Newsletter Simulation Based Engineering & Sciences Year
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ECS System Simulation - Architecture Frequency-Reconfigurable Microstrip Antenna for Software and Performance Optimization from Defined Radio the Early Phases of System Design Optimization of a Boomerang shape using modeFRONTIER
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Multidisciplinary optimization for an IEEE 1902.1 “RuBee” tag International CAE Conference 2012: More than 700 participants
Newsletter EnginSoft Year 9 n°4 -
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Flash Virtual Simulation creates more and more interest in diverse industrial fields and among the young; it is a driving force for innovation, for employment and creates opportunities for companies.
It is in this spirit that we are approaching the New Year at EnginSoft. We invite our readers to enjoy the articles in this Newsletter and to contact us with feedback and ideas for collaboration.
With the CAE Poster Award, EnginSoft fosters and promotes collaborations between industry and universities. At the International CAE Conference 2012, the Award was presented for the first time to six outstanding Young Researchers and businesses for their highly innovative work in the field of simulation. Many of our guests with whom I spoke at the Conference shared the enthusiasm for innovative research and to create new business, to realize visions, to make the most out of the enormous resources we have available in our network.
This issue presents contributions on the use of modeFRONTIER for the optimization of a boomerang shape, the analysis work performed for a frequency-reconfigurable microstrip antenna and the Particle Finite Element Method, PFEM. The latter is an effective numerical technique for multidisciplinary engineering problems which involve fluidsoil-structure interaction. Alenia Aermacchi, Politecnico di Torino and the Università del Salento inform us about ECS System Simulation for architecture and performance optimization. Further case studies cover the development work of Lovato Electric, the Feat Group, the Department of Information Engineering of University of Pisa as well as the use of the Grapheur technology for material selection.
While the year turns to an end, we are building on these foundations, on the opportunities and new activities we have created together with our customers and partners. Success is possible – together.
We introduce the RuBeeCOMP, the INTERCER2 and the “MUSIC” (which stands for: Multi-layer control & cognitive System to drive metal and plastic production line for Injected Components) Research Projects. Our Software Updates feature the latest ANSYS Workbench 14.5 release and SIMPACK, a multi-body simulation tool. We report from the TechNet Alliance Fall Meeting in Germany, the Round Table Meeting of companies from Venetia and offer a comprehensive review of the International CAE Conference to which EnginSoft had the great pleasure to welcome more than 700 attendees. We encourage our readers to download the Conference Proceedings and to look at the inspiring work of the awarded young researchers, the six Posters we also highlight in this Newsletter. Please stay tuned to the EnginSoft Training Program and Event Calendar. We hope to welcome many of you to our CAE courses and events in 2013 and beyond. EnginSoft and the Editorial Team wish you and your families a very happy, healthy and a prosperous New Year!
Stefano Odorizzi Editor in chief
Ing. Stefano Odorizzi EnginSoft CEO and President
Flash
4 - Newsletter EnginSoft Year 9 n°4
Sommario - Contents
CASE STUDIES
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Optimization of a Boomerang shape using modeFRONTIER The Particle Finite Element Method. An effective numerical technique for multidisciplinary engineering problems involving fluid-soil-structure interaction Frequency-Reconfigurable Microstrip Antenna for Software Defined Radio ECS System Simulation - Architecture and Performance Optimization from the Early Phases of the System Design How Geometrical Dimensioning & Tolerancing influence the performances of an electromechanical contactor Research Activities on Slot-Coupled Patch Antenna Excited by a Square Ring Slot Grapheur for Material Selection Studio di fattibilità produttiva attraverso simulazione numerica di processo di forgiatura
RESEARCH & TECHNOLOGY TRANSFER
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Multidisciplinary Optimization for an IEEE 1902.1 “RuBee” tag integrated in a fiber-reinforced composite structure through the “RuBeeCOMP” Numerical Platform
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Meeting conclusivo del progetto "RuBeeCOMP"
SOFTWARE UPDATES
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Le Novità in ambito Mechanical della nuova Release ANSYS Workbench 14.5 Simulating Gear Pairs within SIMPACK
RESEARCH & TECHNOLOGY TRANSFER
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EnginSoft coordinates the new “MUSIC” European Project Modellazione e Progettazione Ottimale di Strutture Ceramiche EnginSoft ed il progetto INTERCER2
TRAINING
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Corsi di Addestramento Software 2013
EVENTS
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International CAE Conference: like never before!
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Trainer europei di ANSYS alla scuola EnginSoft
CAE Poster Award. A reward to the genius of young researchers EnginSoft sostiene le attività di Ricerca dell’Istituto Mario Negri di Milano Le reti d’impresa? Serve un cambio di mentalità CAE Conference 2012 welcomed Sponsors from Japan. Post-conference interviews Event Calendar
Contents
Newsletter EnginSoft Year 9 n°4 -
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Newsletter EnginSoft Year 9 n°4 - Winter 2012
PAGE 16 ECS SYSTEM SIMULATION OF AN ALENIA AIRCRAFT
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PAGE 24 HOW GEOMETRICAL DIMENSIONING & TOLERANCING INFLUENCES THE PERFORMANCES OF AN ELECTROMECHANICAL CONTACTOR
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PAGE 56 INTERNATIONAL CAE CONFERENCE 2012: MORE THAN 700 PARTICIPANTS The EnginSoft Newsletter editions contain references to the following products which are trademarks or registered trademarks of their respective owners: ANSYS, ANSYS Workbench, AUTODYN, CFX, FLUENT and any and all ANSYS, Inc. brand, product, service and feature names, logos and slogans are registered trademarks or trademarks of ANSYS, Inc. or its subsidiaries in the United States or other countries. [ICEM CFD is a trademark used by ANSYS, Inc. under license]. (www.ansys.com) modeFRONTIER is a trademark of ESTECO srl (www.esteco.com)
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RESPONSIBLE DIRECTOR Stefano Odorizzi - newsletter@enginsoft.it PRINTING Grafiche Dal Piaz - Trento The EnginSoft NEWSLETTER is a quarterly magazine published by EnginSoft SpA
Contents
Autorizzazione del Tribunale di Trento n° 1353 RS di data 2/4/2008
PAGE 41 MULTIDISCIPLINARY OPTIMIZATION FOR AN IEE 1902.1 “RUBEE” TAG
ESTECO www.esteco.com CONSORZIO TCN www.consorziotcn.it • www.improve.it
6 - Newsletter EnginSoft Year 9 n°4
Optimization of a Boomerang shape using modeFRONTIER A boomerang is a flying object apparently simple but particularly challenging for the complex physics modeling, since it should indeed involve: • six degrees of freedom body dynamics; • aerodynamics of rotational blades; • personal capabilities of the thrower; In this paper we show how the design optimization software modeFRONTIER, developed by ESTECO, can be employed for a non-standard problem consisting in the numerical simulation of the boomerang flight and the final optimization of its shape. The boomerang trajectory is obtained by means of a dynamic model integrated to a CFD analysis able to compute aerodynamic coefficients. To steer the complete optimization process modeFRONTIER is coupled to Catia v5 for the boomerang shape modification, to MATLAB for the dynamic simulation, and to Star-CCM+ for aerodynamic analysis. Moreover, dedicated RSM (Response Surfaces Methods) available in modeFRONTIER are used to extrapolate the aerodynamic coefficients as a function of the boomerang angle of incidence and velocity, as required by the dynamic model, allowing a reduced number of CFD analyses for each geometric configuration. Different design simulations are therefore automatically executed by modeFRONTIER, following a dedicated optimization strategy until the optimal geometry of the boomerang is found accordingly to the specified requirements, such as minimum energy for the launch and desired accuracy in returning. 1. Equations of the boomerang motion Considering that a boomerang spins fast, it is possible to write the so-calleds moothed boomerang equations in which the different quantities (velocities, angles, forces) are timeaveraged over a boomerang rotation:
where: Iz is the maximum boomerang principal moment of inertia; V is the velocity magnitude of the boomerang center
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of mass; m the boomerang mass; ψ is the angle of incidence of the boomerang; ϑ, φ, ψ are the Euler angles of a xyz reference system partially fixed on the boomerang (such that the boomerang center of mass is always placed in the xyz origin, the z axis is always directed as the maximum boomerang moment of inertia axis, namely normal to the section plane shown in Fig.3, and the projection of the boomerang center of mass velocity on the xy planes is directed as the –x axis); ωz the boomerang angular velocity around the z axis; Tx, Ty, Tz, Fx, Fy, Fz, are torque and force components in the xyz reference system, basically due to the interaction between the boomerang and the air and the gravity force. The gravity force can be expressed in the xyz reference system as:
The absolute position of the boomerang center of mass can be found as function of the previous parameters by:
The equations of motion can be integrated numerically (high order Runge-Kutta method) once the initial conditions are provided and the forces and torques are available at any time step. A candidate boomerang trajectory can therefore be simulated through the flowing steps: i) for a certain number of Ψ and U pairs (where U=V/ωza), with a distance between the boomerang center of mass and the farthest boomerang point from the center of mass) the corresponding not-dimensional values of F and T are computed by CFD simulations: a dimensional analysis can prove indeed that F and T depend only on Ψ and U for a given boomerang geometry and for a Reynolds number range typical of boomerang flights; ii) response surfaces for F(Ψ,U) and T(Ψ,U) are built; iii) equations of motion are integrated starting from given initial conditions and using the response surfaces computed previously to express forces and torques at any position and time step. The trajectory of the boomerang is affected by the initial conditions, namely by the way the boomerang is launched.
Newsletter EnginSoft Year 9 n°4 -
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Four launching parameters are considered (they will be automatically tuned for each candidate boomerang by the optimization methodology described in section 4): • V: initial boomerang translational velocity; • Spin: initial boomerang spin; • Aim: angle between the initial boomerang translational velocity and the horizontal plane; • Tilt: angle between the initial boomerang rotational plane and the vertical axis (0° tilt corresponds to a vertical boomerang plane of rotation). 2. Boomerang Parameterization The boomerang geometry chosen for the optimization will be the classical two arms “V” and “Ω” shape type. The most important parameters that affect the boomerang behavior are linked to the blades profile, the angle between the two arms and the dihedral of the arms. A total number of 9 input parameters has been defined. A. Blade profiles Changing the profile by playing with the angle of attack and cutting on the top of the leading and trailing edge can change a lot the lift provided by the arm. The lift in particular affects the turn capability of the Fig. 1 - Effect on blade profile of Bezier boomerang (precession control points effect). The arc blades are in general designed with a positive angle of attack; this helps the boomerang plane to lay down and to float in air. For the parametric boomerang geometry a flat bottom airfoil has been chosen. The blade profiles are built by a Bezier parametric curve, with 4 control points. The profile shape is modified by the changing vertical and horizontal position of the Bezier control points. In this way it is possible to change the angle of attack and the thickness of the blades (see Fig.1). The profiles of the leading and of the trailing arm are controlled by the same parameters, in order to reduce their total number. In particular the vertical position of the trailing arm is set as a fraction of the vertical position of the leading arm. B. Dihedral angle Boomerang arms usually have a positive dihedral angle of about 10°-15°; the dihedral affects both the lift and the lay down velocity of the rotation plane, keeping practically unchanged the mass of the boomerang. The boomerang parametric model is provided with the two parameters α and d that allow to change the dihedral by removing a small amount of material from the boomerang arms tips (Fig.2). The α parameter is basically the stabilizer’s angle of attack.
Fig. 2 - Leading and trailing edges; dihedral angle.
C. Angle between arms This angle usually ranges between 70° and 140°. In fact, this parameter has an important effect on the boomerang stability. The length of the arms is fixed to keep a constant overall size of the boomerang. 3. Aerodynamic forces computation details by CFD The CFD software employed is Star-CCM+. The approach we considered consists in using two reference systems - one external and inertial, the other fixed with respect to the boomerang and having its origin placed in the boomerang center of mass. Also, two domains and two grids are used: the first is spherical, having its origin placed in the boomerang center of mass and associated to the boomerang reference system; the second corresponds to an external parallelepiped shape associated to the external reference system. The internal spherical domain is provided with a rotation velocity around an axis normal to the boomerang plane and passing through the boomerang center of mass. The information exchange between the two domains is provided by an interface boundary that allows to interpolate the field values. In Star-CCM+, a polyhedral mesh with prisms layers at the boomerang walls is defined within the sphere around the boomerang and an hexahedral mesh is defined in the rest of the domain (Fig.3). The two-equations RANS SST (Shear Stress Transport) turbulent model, with wall functions, is chosen and a segregated solver with constant density is employed. A mesh size of about 2.5 millions of cells has been defined, this being a good tradeoff between Fig. 3 - Particular of a mesh section
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8 - Newsletter EnginSoft Year 9 n°4
Fig. 4 - CFD results on different revolution frames
accuracy and computational efforts. Fig.4 shows the pressure field on a boomerang surface in different time steps during a rotation. It is possible to notice that the pressure force on each arm changes a lot during the rotation according to the relative position of the blades with respect to the translational velocity. At the end of the numeric simulation (for a given Ψ,U pair) the averaged forces and torques acting during the rotation are computed and then the corresponding F and T are available. 4. Process flow automation in modeFRONTIER The whole process aiming at evaluating and optimizing the performances of the boomerang has been completely automatized through the software modeFRONTIER. In this modular environment, the complete process flow is defined by the user, who can select among several available optimization algorithms, including Genetic and Evolutionary Algorithms, Game Strategies, Gradient-based Methodologies, Meta-Models and Robust Design Optimization.
Fig. 5 - modeFRONTIER main workflow
modeFRONTIER effectively automates the computation of the boomerang trajectory through the following steps: 1. modify the boomerang Catia model parameters; 2. obtain the updated geometry (stl file) from Catia and transfer it to Star-CCM+ execution module; 3. launch Star-CCM+ to build the computational mesh; 4. launch different Star-CCM+ simulations using the same mesh prepared as above varying U and Ψ parameters for an appropriate number of samples; for each U and Ψ pair the corresponding forces and torques F and T are obtained;
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5. use the set of simulations computed in iv) as training set to build in modeFRONTIER response surfaces to obtain F(Ψ,U) and T(Ψ,U) over the whole range of variation of Ψ,U 6. pass the response surfaces and the boomerang inertia data to a MATLAB script to compute the trajectory by integrating equations of motion using a 4th order RungeKutta method; 7. run an internal optimization for the given configuration to tune the four launching parameters (by minimizing the arrival distance); 8. the main multi-objective algorithm assesses how good the trajectory is with respect to specified objectives (total energy needed for the launch to be minimized) 9. the steps i)-viii) are repeated automatically by the algorithm until one or more optimal configurations are obtained. The modeFRONTIER workflow is shown in Fig.5. In particular, on the top we find the nodes (green subsystem) that define the range of variations of all the geometrical parameters, then the process flow (black line) starts with the interfaces to select the optimization algorithms and set their options, to continue with the CATIA direct interface that allows to automatically update the geometric model at the variation of the parameters, obtaining as results the updated Stl model, which is transferred to the following script node used to run Star-CCM+ to create the mesh for the proposed geometry. The mesh (.sim file) is then transferred to the following application node, which basically launches in batch mode another modeFRONTIER project file, running a set of CFD computations through Star-CCM+ on the same mesh varying U and Ψ parameters, as described at point iv) above. The output of the internal modeFRONTIER project is a Response Surface (RSM) or Metamodel, based on the available training set, able to extrapolate F(Ψ,U) and T(Ψ,U) over the whole range of variation of the two parameters (fig.6). The algorithm used for the RSM training is Kriging and the model is automatically exported as a C-script, which can be read by MATLAB. The last application node in the process flow is another modeFRONTIER project node, called “launch_parameters_tuning”. This node actually runs another optimization project in batch mode, using as input variables the four launch parameters described in section 1. The boomerang shape is fixed and the objective is defined by the minimization of the distance from the arrival position and the launching position. For this purpose, a fast monoobjective algorithm is used (Simplex) and the project just executes a MATLAB script through the corresponding direct interface for each set of launching parameters; basically the script drives a Runge-Kutta integration to compute the
Newsletter EnginSoft Year 9 n°4 -
Fig. 6 - Response surfaces of boomerang aerodynamic forces
boomerang trajectory (retrieving the needed F(Ψ,U) and T(Ψ,U) values for each integration time step directly from the Response surface available for each boomerang geometry). The final outcome of the modeFRONTIER Batch node in the main process flow for each boomerang geometry is therefore its tuned trajectory, whose performances are to be optimized in the external loop. For this purpose, from this node the following outputs are extracted: • Range: this is the maximum distance reached by the boomerang during its flight; it has just been considered as a constraint in the optimization, to penalize configurations of too small range;; • Accuracy: this is the difference between the position from which the boomerang is launched and the position where the boomerang returns (optimized by the internal loop as described above for each boomerang candidate solution) • Energy: this is the energy (translational plus rotational) necessary to launch the boomerang, that is a quantity to be minimized (to reduce the effort for the thrower). 5. Optimization Strategy and Optimization Results Several tests were performed in order to find the proper number of simulations required to create enough accurate response surfaces. It has been found that a matrix of 12 points guarantees an error of approximation lower than 5% and this was the size of the training set finally selected. This means that each boomerang trajectory computation needs 12 CFD simulations. For this reason a classical multi-objective optimization algorithm that may require hundreds of designs evaluations is not practically feasible, therefore a different strategy, based on the Game Theory (Hierarchical Games), has been chosen. As indicated in the previous chapter, two different objectives (returning accuracy and launch global energy) have to be considered. Actually, any candidate solution is first optimized by the internal workflow in order to tune the launching parameters (follower player); then, the identified optimal solution is evaluated by the external optimization workflow which handles the energy objective minimization by changing properly the geometrical parameters (leader player). Note that for both the internal and external optimizer the same modeFRONTIER algorithm, Simplex, has
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been used due to its efficiency to solve single-objective problems in few iterations. Fig.7 reports the global results of the optimization process, in the space of the objectives and constraints considered. In particular the abscissa reports the launch energy (Joule), the ordinate indicates the range (meters), and the color of the bubbles reports the returning accuracy for each design (distance in meters). At the end of the process, one of the optimal boomerang configuration has been chosen and its geometry and trajectory are also reproduced in Fig.8. The energy required to launch the boomerang is 3.5 J, the ratio of rotational with total energy is only 7% that corresponds to an initial spin of about 4 Hz and to an initial translational velocity equal to 15 m/s; the tilt angle is 0°, while the aim is about 20°. This set should make the boomerang launch pretty easy, with a range of 14.5 m. In conclusion, this paper has described an automatic and efficient methodology for the multi-objective optimization of a boomerang shape, resulting an interesting benchmark and proof of concept to illustrate the multi-objective and multidisciplinary capabilities of the optimization environment modeFRONTIER. Rosario Russo, Alberto Clarich - ESTECO Spa Enrico Nobile, Carlo Poloni - Università di Trieste For more information: Francesco Franchini, EnginSoft info@enginsoft.it
Fig. 7 - Optimization results
Fig. 8 - Optimal boomerang configuration and trajectory
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10 - Newsletter EnginSoft Year 9 n°4
The Particle Finite Element Method. An effective numerical technique for multidisciplinary engineering problems involving fluid-soil-structure interaction Introduction The analysis of problems involving the interaction of fluids, soil/rocks and structures is relevant in many areas of engineering. Examples are common in the study of landslides and their effect on reservoirs and adjacent structures, off-shore and harbour structures under large waves, constructions hit by floods and tsunamis, soil erosion and stability of rockfill dams in overspill situations, excavation and drilling problems in civil and petroleum engineering, etc. The author and his group have developed in previous works a particular class of Lagrangian formulation for solving problems involving complex interactions between (free surface) fluids and solids. The so-called particle finite element method (PFEM, www.cimne.com/pfem), treats the mesh nodes in the fluid and solid domains as particles which can freely move and even separate from the main fluid domain representing, for instance, the effect of water drops. A mesh connects the nodes discretizing the domain where the governing equations are solved using a stabilized FEM. An advantage of the Lagrangian formulation used in PFEM is that the non-linear and non symmetric convective terms disappear from the fluid equations. The difficulty is however transferred to the problem of adequately (and efficiently) moving the mesh nodes. In the next section the key ideas of the PFEM are outlined. Next the basic equations for a general continuum using a Lagrangian description and the formulation are schematically presented. We present several examples of application of the PFEM to solve multidisciplinary FSSI problems such as the motion of rocks by water streams, the stability of breakwaters and constructions under sea waves, the study of a landslide falling into a reservoir, the sinking of ships and the collision of ships with ice blocks.
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The basis of the particle finite element method In the PFEM both the fluid and the solid domains are modelled using an updated Lagrangian formulation. That is, all variables are assumed to be known in the current configuration at time t. The new set of variables in both domains is sought for in the next or updated configuration at time t + Δt. The finite element method (FEM) is used to solve the equations of continuum mechanics for each of the subdomains. Hence a mesh discretizing these domains must be generated in order to solve the governing equations for each subdomain in the standard FEM fashion. The quality of the numerical solution depends on the discretization chosen as in the standard FEM. Adaptive mesh refinement techniques can be used to improve the solution.
Fig. 1 - Scheme of a typical solution with PFEM. Sequence of steps for moving a “cloud” of nodes representing a domain containing a fluid and a solid part from time n (t=tn) to time n+2 (t=tn + 2Δt)
Newsletter EnginSoft Year 9 n°4 -
For clarity purposes we will define the collection or cloud of nodes (C) pertaining to the analysis domain (V) containing the fluid and solid subdomains and the mesh (M) discretizing both domains. A typical solution with the PFEM involves the following steps. 1. The starting point at each time step is the cloud of points in the fluid and solid domains. For instance nC denotes the cloud at time t = tn (Figure 1). 2. Identify the boundaries for both the fluid and solid domains defining the analysis domain nV in the fluid and the solid. This is an essential step as some boundaries (such as the free surface in fluids) may be severely distorted during the solution, including separation and reentering of nodes. The Alpha Shape method is used for the boundary definition. 3. Discretize the fluid and solid domains with a finite element mesh. nM We use an effect mesh generation scheme based on the extended Delaunay tesselation. 4. Solve the coupled Lagrangian equations of motion for the overall continuum. Compute the state variables in at the next (updated) configuration for t + Δt: velocities, pressure and viscous stresses in the fluid and displacements, stresses and strains in the solid. 5. Move the mesh nodes to a new position n n+1C where n+1 denotes the time tn + Δt, in terms of the time increment size. This step is typically a consequence of the solution process of step 4. 6. Go back to step 1 and repeat the solution for the next time step to obtain n+2C (Figure 1). We emphasize that the key differences between the PFEM and the classical FEM are the remeshing technique and the identification of the domain boundary at each time step. Generation of a new mesh A key point for the success of the PFEM is the fast regeneration of a mesh at every time step on the basis of the position of the nodes in the space domain. In our work the mesh is generated using the so-called extended Delaunay tesselation (EDT). As a general rule for large 3D problems meshing consumes around 15% of the total CPU time per time step, while the solution of
Fig. 2 - Modelling of contact conditions at a solid-solid interface with the PFEM
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the equations (with typically 3 iterations per time step) and the system assembly consume approximately 70% and 15% of the CPU time per time step, respectively. These figures refer to analyses in a single processor Pentium IV PC and prove that the generation of the mesh has an acceptable cost in the PFEM. Indeed considerable speed can be gained using parallel computing techniques. Identification of boundary surfaces One of the main tasks in the PFEM is the correct definition of the boundary domain. Boundary nodes are sometimes explicitly identified. In other cases, the total set of nodes is the only information available and the algorithm must recognize the boundary nodes (Figure 2). In our work we use a Delaunay partition for recognizing boundary nodes and, hence, boundary surfaces. This is performed by using the so-called Alpha Shape method. This method also allows one to identify isolated fluid particles outside the main fluid domain. These particles are treated as part of the external boundary where the pressure is fixed to the atmospheric value. We recall that each particle is a material point characterized by the density of the solid or fluid domain to which it belongs. The mass lost when a boundary element is eliminated due to departure of a node from the analysis domain containing a fluid is regained when the node falls down and a new boundary element is created by the Alpha Shape algorithm. The boundary recognition method is useful for detecting contact conditions between the fluid domain and a boundary, as well as between different solids as detailed in the next section. Treatment of contact conditions in the PFEM Known velocities at boundaries in the PFEM are prescribed in strong form to the boundary nodes. These nodes might belong to fixed external boundaries or to moving boundaries. Contact between fluid particles and fixed boundaries is accounted for by the incompressibility condition which naturally prevents fluid nodes to penetrate into the solid boundaries. The contact between two solid interfaces is treated by introducing a layer of contact elements between the two interacting solid interfaces. This layer is automatically created during the mesh generation step by prescribing a minimum distance (hc) between two solid boundaries. If the distance exceeds the minimum value (hc) then the generated elements are treated as fluid elements. Otherwise the elements are treated as contact elements where a relationship between the tangential and normal forces and the corresponding displacement is introduced (Figure 2). This algorithm allows us to identify and model complex frictional contact conditions between two or more interacting bodies moving in water in an extremely simple manner. The algorithm can also be used effectively to model frictional contact conditions between rigid or elastic solids in structural mechanics applications. Modeling of bed erosion Prediction of bed erosion and sediment transport in open channel flows are important tasks in river and environmental
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12 - Newsletter EnginSoft Year 9 n°4 engineering. Bed erosion can lead to instabilities of the river basin slopes. It can also undermine the foundation of bridge piles thereby favouring structural failure. Modeling of bed erosion is also relevant for predicting the evolution of surface material dragged in earth dams in overspill situations. Bed erosion is one of the main causes of environmental damage in floods. In a recent work we have proposed an extension of the PFEM to model bed erosion. The erosion model is based on detaching elements belonging to the bed surface in terms of the frictional work at the surface originated by the shear stresses in the fluid. The resulting erosion model resembles Archard law typically used for modeling abrasive wear in surfaces under frictional contact conditions. Sediment deposition can be modeled by an inverse process. Hence, a suspended node adjacent to the bed surface with a velocity below a threshold value is attached to the bed surface.
Fig. 5 - Erosion of a soil mass due to sea waves and the subsequent falling into the sea of an adjacent lorry
Fig. 6 - Simulation of landslide falling on constructions using PFEM
Fig. 3 - Breaking waves on breakwater slopes containing reinforced concrete blocks
Examples Impact of sea waves on piers and breakwaters Figure 3 shows the analysis of the effect of breaking waves on two different sites of a breakwater containing reinforced concrete blocks (each one of 4x4x4 mts). The figures correspond to the study of Langosteira harbour in A Coruña, Spain using PFEM. Soil erosion problems Figure 4a shows the capacity of the PFEM for modelling soil erosion, sediment transport and material deposition in a river bed. The soil particles are first detached from the bed surface under the action of the jet stream. Then they are transported by the flow and eventually fall down due to gravity forces into the bed surface at a downstream point. Figure 4b shows the progressive erosion of the unprotected part of a breakwater slope in the Langosteira harbour in A Coruña, Spain. The non protected upper shoulder zone is progressively eroded under the sea waves. Falling of a lorry into the sea by erosion of the road slope due to sea waves Figure 5 shows a representative example of the progressive
Fig. 4 - (a) Erosion, transport and deposition of soil particles at a river bed due to an impacting jet stream (b) Erosion of an unprotected shoulder of a breakwater due to sea waves
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Fig. 7 - Lituya Bay landslide. Left: Geometry for the simulation. Right: Landslide direction and maximum wave level
erosion of a soil mass adjacent to the shore due to sea waves and the subsequent falling into the sea of a 2D object representing the section of a lorry. The object has been modeled as a rigid solid. This example and the previous ones, although still quite simple and schematic, show the possibilities of the
Fig. 8 - Lituya Bay landslide. Evolution of the landslide into the reservoir obtained with the PFEM. Maximum level of generated wave (551 mts) in the north slope
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height observed was 208 mts, while the PFEM result (not shown here) was 195 mts (6% error). Simulation of sinking of ships The PFEM can be effectively applied for simulating the sinking of ships under a variety of scenarios. Figure 9 shows images of the 2D simulation of the sinking of a cargo vessel induced by a breach in the bow region. Figure 10 displays a 3D simulation of the skinking of a simple fisherman boat induced by a hole in the side of the hull. These examples evidence the potential of PFEM for the study of the sinking of ships. Colision of boat with ice blocks Figures 11 shows an example of the application of PFEM to the study of the collision of a ship with floating ice blocks. The boat and the ice blocks have been modelled as rigid bodies in this example. Indeed, the deformation of the ship structure due to the ice-ship interaction forces can be accounted for in the analysis.
Fig. 9 - 2D simulation of the sinking of a cargo vessel due to a breach in the bow region. (a) Water streamline at different times. (b) Water velocity pattern at different times during sinking
PFEM for modeling complex FSSI problems involving soil erosion, free surface waves and rigid/deformable structures.
Conclusions The particle finite element method (PFEM) is a promising numerical technique for solving fluid-soil-structure interaction (FSSI) problems involving large motion of fluid and solid particles, surface waves, water splashing, frictional contact situations between fluid-solid and solid-solid interfaces and bed erosion, among other complex phenomena. The success of the PFEM lies in the accurate and efficient solution of the equations of an incompressible continuum using an updated Lagrangian formulation and a stabilized finite element method allowing the use of low order elements with equal order interpolation for all the variables. Other essential solution ingredients are the efficient regeneration of the finite element mesh, the identification of the boundary nodes using the Alpha-Shape technique and the simple algorithm to treat frictional contact conditions and erosion/wear at fluid-solid and solid-solid interfaces via mesh generation. The examples presented have shown the potential of the PFEM for solving a wide class of practical FSSI problems in engineering.
Modelling of landslides The PFEM is particularly suited for modelling landslide motion and its interaction with structures and the environment. Figure 6 shows a simulation using PFEM of a soil mass representing a landslide falling on four constructions modelled as rigid body solids. A case of much interest is when a landslide occurs in the vicinity of a reservoir. The fall of debris material into the reservoir typically induces large waves that can overtop the dam originating an unexpected flooding that can cause severe damage to the constructions and population in the downstream area. We present some results of the 3D analysis of the landslide produced in Lituya Bay (Alaska) on July 9th 1958 (Figure 7). The landslide was originated by an earthquake and Eugenio Oñate mobilized 90 millions tons of rocks that fell on the bay International Center for Numerical Methods originating a large wave that reached a hight on the opposed in Engineering (CIMNE), Spain slope of 524 mts. Figure 8 shows images of the simulation of the Universitat Politècnica de Catalunya (UPC), Spain Lituya Bay landslide with PFEM. PFEM results have been compared with observed values of the maximum water level in the north hill adjacent to the reservoir. The maximum water level in this hill obtained with PFEM was 551 mts. Fig. 10 - 3D simulation of the sinking of a boat induced by a hole in the side of the hull This is 5% higher than the value of 524 mts. observed experimentally. The maximum height location differs in 300 mts from the observed value. In the south slope the maximum water Fig. 11 - 3D simulation of a boat colliding with five ice blocks
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14 - Newsletter EnginSoft Year 9 n째4
Frequency-Reconfigurable Microstrip Antenna for Software-Defined Radio The increasing demand for portable devices with wireless connectivity within a wide frequency spectrum presents an ambitious challenge for the designer of the RF front-end who has to manage different wireless standards (GSM, UMTS, WiMAX, WiFi, Bluetooth, LTE). Covering several frequency bands simultaneously with a single antenna can be a very demanding task, which is why the employment of many different antennas integrated in the device and the use of multiband or broadband antennas might be a feasible solution for the problem. The use of different antennas implies an increase of the overall cost and space requirements. Broadband antennas transmit and receive signals within a large bandwidth but they may suffer an unbearable deterioration of the signal to noise ratio and thus a reduction of the overall efficiency of the system. Moreover, the electromagnetic spectrum is a shared resource that is more and more congested with the increasing number of users of wireless devices and the further exploitation of the available frequencies by other services poses practical and regulatory difficulties. To cope with this problem, the employment of an unused part of the spectrum or the opportunistic and temporary use of a shared portion may offer new resources.
upgrade, without changing the controlled hardware. This ambitious objective imposes strict requirements to the capabilities of the device radio front-end especially in terms of the requested frequency agility necessary for the smart and dynamic adaptation to the wireless environment. In particular, severe constraints are placed on critical components such as filters, matching networks and antennas. The SDR architecture requires a reconfigurable antenna which is able to modify one, or a combination, of its fundamental radiation properties depending on the adopted scheme [6]. A radiating device can exhibit a frequency agility, which allows to set its instant working frequency, a change in pattern shape, or an alteration of the electric field polarization. The reconfiguration is obtained by adjusting the path of currents on the antenna or even by altering the geometry of the radiating device. The three aforementioned degrees of reconfigurability can be realized by recurring to different technologies among which electrical RF switches such as PIN diodes and varactors, photoconductive elements or MEMS. Different kinds of antennas have been proposed for the enhancement of the SDR radio frontend including PIFAs, monopoles and patches.
The Cognitive Radio (CR) concept has been proposed as a Within this framework, we have recently developed a solution since the related CR radio network is able to evaluate reconfigurable microstrip patch antenna by using PIN diodes the instant occupancy of spectrum and decides on this basis as RF switches whose biasing network is how to allocate services on temporarily software-controlled via a PIC unoccupied parts of the EM spectrum. microcontroller. The microstrip patch This recent paradigm of communication antenna has been chosen for its low allows an efficient spectrum usage but profile, robustness and easy also poses some challenges, with regard manufacturing. The aim is to obtain an to hardware and software, which have antenna with a reconfigurable motivated the rise of the Software frequency response between 850 MHz Defined Radio (SDR) concept during the and 3.5 GHz by simply changing the last years. A device based on SDR is an state of the RF switches. After a integrated system which must exhibit preliminary optimization study based on extreme hardware performance to the cavity model of the patch antenna, support the necessary software-based we have considered the configuration signal processing and guarantee the shown in Fig. 1 in which five PIN diodes desired flexibility. The final goal is Fig. 1 - Top view of the frequency-reconfigurable microstrip patch antenna. The continuous circles are able to guarantee a proper sweep of therefore to implement most of the radio indicate group#1 whereas dashed circles designate the working frequency. The positions of system in software, easy to update or group#2.
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the RF switches have been chosen by inspecting the path of the currents on the patch surface to individuate the most suitable placement of the diodes to guarantee the current flow. The overall size of the patch antenna is 84 mm × 70 mm. It is worthwhile to mention that the size of each element in the antenna and the position of the PIN diodes were chosen under two imposed constraints. First of all, in order to reduce the complexity of the design, we aimed at a configuration where all the RF-switch biasing lines had to be placed on the top layer of the antenna substrate, avoiding any cut in the ground plane. Next, we also searched for a solution without any matching network thus requiring in each RF-switch state an impedance close to the 50 Ohm of the feeding line. Two shorting pins with a 1.0-mm-diameter were inserted as illustrated in Fig. 1, the former in one of the outer sections and the latter in the inner element. To obtain a correct evaluation of the antenna behavior, the diodes have been considered by using their circuit model in the Ansoft HFSS simulations (Fig. 2) instead of substituting them as an open circuit in the "Off" case and as a short circuit when in "On" state. The employed PIN diode is an Avago HSMP-4890 which presents Rs = 2.5 Ohm, L = 1 nH, CT = 0.3 pF and RP in the order of KOhm. The PIN diodes were placed by using silver conductive epoxy to avoid overheating of the device. Fig. 2 - PIN diode circuit In our design the five PIN diodes model for the "On" state (a) have been divided into two groups and "Off" state (b). (continuous and dashed circles as shown in Fig.1) thus providing four possible configurations. Each group allows current to flow when the diodes are in "On" state whereas the propagation of the RF signal is interrupted when they are set to "Off" state. The biasing network comprises two lines on the top of the dielectric substrate which connect each of the outer sections of the patch to the DC source. A RF block is necessary to isolate the RF and DC source on these biasing lines. Moreover, the inner element of the antenna and the other one inside the simil-loop element are connected to the ground plane by using the 1.0-mm-diameter via. This configuration allows modifying the state of the two RF-switch groups by simply changing the voltage between the ground plane and the two lines connected to each antenna side. In order to change on demand the instantaneous frequency, we have programmed a PIC16F688 flash microcontroller to switch among the four possible configurations described above and we have Fig. 3 - The antenna configuration is completely software-controlled by using the directly connected the PC which operates on the PIC microcontroller prototype board to a to change the state of PIN diodes.
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Fig. 4 - Frequency response of the antenna when PIN diodes belonging to group#2 are in "On" state and others are in "Off" state.
laptop through an USB interface (Fig. 3). Therefore the activation and deactivation of the RF switches is performed by a microcontroller which can change the working frequency on the basis of the information collected by another antenna (sensing antenna) which is scouting the available frequency slots, as proposed in the CR paradigm. A comparison between the simulated and measured S11 parameters for the configuration with group#1 in OFF state and group#2 in ON state is reported in Fig.4 and the agreement is satisfactory except for some frequency shifts which could be attributed to discrete component tolerances and soldering effects.
Fig. 5 - Comparison between the simulated (continuous line) and measured (dashed line with triangles) radiation patterns at 850 MHz: φ = 0 deg., φ = 90 deg.
The simulated and measured patterns on the xz (φ = 0) and yz (φ = 90) planes are reported in Fig. 5. From the inspection of the results it is apparent that there is no significant distortion of the antenna pattern caused by the PIC microcontroller and the biasing lines. Ing. Simone Genovesi, Prof. Agostino Monorchio Microwave and Radiation Lab., Dip. Ingegneria dell'Informazione (www.mrlab.it) Università di Pisa For more information, please contact: simone.genovesi@iet.unipi.it agostino.monorchio@iet.unipi.it
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ECS System Simulation - Architecture and Performance Optimization from the Early Phases of the System Design In today’s aircraft thermal design, we can observe a trend towards electronics systems integration characterized by higher heat densities and a more frequent use of composite primary structures. All these factors require robust thermal management and thermal architecture design already at the preliminary design stages. The thermal architecture will have to be developed in order to mitigate thermal risks for temperature-sensitive equipment as well as to limit the aircraft systems overdesign. The improvement and optimization of the thermal architecture is regarded as one of the key success factors for future aircraft developments. It requires a complete pyramid of simulation tasks to be set up, from the individual equipment to aircraft section simulation, to the global aircraft thermal analysis. Many difficulties arise from this simulation framework due to the variety of physical models, partners, techniques and tools used at each level of the pyramid.
In this context, the aim of this paper is to describe an Environmental Control System design approach as applied in Alenia Aermacchi. The main technical challenges addressed in this paper are: • Air conditioning pack architecture design • Air distribution line design and trade-off study, • Multidisciplinary optimization of the air distribution system components • A/C cabin thermal environment evaluation and occupants’ thermal comfort. Background The air conditioning system is designed in such a way that it maintains the air within the pressurized fuselage
Fig. 2 - Thermal aircraft schematic
Fig. 1 - A/C air conditioning pack and air distribution system
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Table 1 - Electrical equipment dissipated power
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compartment at the required level of pressure, temperature, flow rate and purity. The air is supplied to the system from the engine compressor, the hot compressed air is cooled and conditioned in the air conditioning pack before being distributed to the various compartments through the air conditioning system (see Figure 1).
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As shown in Figure 4, the standard air condition pack architecture has been considered. Figure 4 illustrates also the mono-dimensional model built in LMS Amesim. The heat exchanger mono-dimensional model (low fidelity model) has been validated by comparing its results with CFD model results (high fidelity model). In Figure 5, we can see the validation analysis results.
Accordingly, in order to guarantee a comfortable A/C cabin environment, it is necessary to design and optimize the air conditioning pack and air distribution system. Air conditioning pack architecture design Requirements This study focuses on the following requirements: • A/C schematic configuration (see Figure). • Thermo-acoustic insulation U factor. • Electrical equipment dissipated power (see Table 1). • Temperature requirements for cabin/ cockpit. • Environmental envelope (see Figure 3). • The certification and performance requirements of ECS are reported below: o Minimum fresh flow per passenger: 0.55 lb/min. o Minimum fresh flow per crew member: 10 cfm. o Minimum fresh flow per galley 15 cfm. o Maximum ratio recirculation / total flow 0.4. o Maximum fresh flow per passenger/crew member for single pack operations 0.4. o Cabin stabilized temperature between 21°C -27°C. o Cockpit stabilized temperature between 21°C-27°C. Methodology The design of the air conditioning pack architecture has been reached through the following steps: • Definition of air conditioning pack monodimensional model. • Definition and validation of heat exchanger mono-dimensional model. • Definition of A/C cabin thermal monodimensional model. • Optimization of heat exchanger design, in order to meet certification and performance requirements.
Fig. 3 - Environmental envelope
Fig. 4 - ECS pack 1D- model
Fig. 5 - Heat exchanger size
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18 - Newsletter EnginSoft Year 9 n°4 • Steady state, cruise cold day (40 kft, -70 °C, Mach 0.85, 20% passengers) The heat exchanger has been defined in terms of its geometrical characteristics and number of plates. As shown in Figure 7, the analysis results confirm the compliance of the air conditioning pack architecture with the certification and performance requirements.
Fig. 6 - A/C mono-dimensional thermal model
Air distribution line design and trade-off study In order to determine the air conditioning pack architecture, the second step focused on the definition of the air distribution system. The latter depends on the following aspects: • Performance in terms of pressure losses. • Integration in aircraft. • Reliability and maintainability. Two different architectures have been analyzed. The first one (Architecture A) shown in Figure 8 is a parallel architecture composed of an underfloor line and a low pressure air distribution line that allow to distribute the airflow coming from the mixing chamber in parallel through the risers.
Fig. 7 - Performance of air conditioning pack
Fig. 8 - Air distribution system CAD model – Architecture A
Fig. 10 - Mono-dimensional model Architecture A.
Fig. 9 - Air distribution system CAD model – Architecture B
In order to design the air cycle machine and heat exchanger, the cabin aircraft mono-dimensional thermal model shown in Figure 6 has been built. It allowed to evaluate the cabin thermal environment and hence the compliance with varying pack performance depending on the heat exchanger design. The operating conditions analysed have been: • Steady state, ground hot day (ISA+25, 100% passengers) • Steady state, ground cold day (ISA-55, 20% passengers) • Steady state, cruise hot day (40 kft, -35°C, Mach 0.85, 100% passengers)
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Fig. 11 - Mono-dimensional modelArchitecture B.
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As boundary conditions we assumed the data reported below in various flight conditions, then the steady state analysis has been carried out: • Temperature, air flow, pressure and humidity coming from the air conditioning pack. • External conditions in terms of temperature. • Equipment and light heat load. • Passengers heat load. Figure 12 shows the analysis results in terms of pressure drop vs mass flow curve. In particular, the results highlight that the air distribution system pressure losses of Architecture A are higher than those of Architecture B.
Fig. 12 - Pressure loss vs massflow curves
The second one (Architecture B) shown in Figure 9 is a sequential architecture where the under floor is much limited, and the cabin air distribution system is developed above the floor. Starting from the CAD model shown above, a monodimensional model for each architecture has been built in LMS Amesim (see Figures 10 and 11). The mono-dimensional models are composed of the following parts: • Connection with air conditioning pack mono-dimensional model. • Cockpit line • Cabin line • Simplified A/C thermal model as thermal node. • Internal macro that allows to simulate the physiology of the passengers in terms of heat load and humidity released.
Fig. 13 - Technical performance measure
A comparison analysis has been performed by means of a Technical Performance Measure (TPM) methodology. First, all of the key requirements (performance, system integration in the aircraft, RMT) have been defined, categorized and weighted according to their degree of importance. Key factors and preferences have been established on the basis of Alenia’s experiences. Normalized weights of 0-1 range have been assigned as per the above to each key requirement. Then, each requirement has been split into sub-requirements, as follows: • Performance: o Pressure loss. • System Integration in the aircraft: o Influence on cabin noise; o Weight; o Ease of installation. • RMT o Reliability; o Maintainability. Each sub-requirement has been weighted according to its degree of importance compared to the others. Then, each weight has been normalized in absolute terms, in accordance with the key requirements. Also a score has been assigned to each sub-requirement, as follows: • 1 = VERY POOR: the proposed solution does not meet the system’s requirements; • 2 = POOR: the proposed solution does not meet the system’s requirements but the requirement deviation is acceptable;
Fig. 14 - CAD model for Outlet
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20 - Newsletter EnginSoft Year 9 n°4
Fig. 15 - Parametric model
• 3 = ACCEPTABLE: the proposed solution meets the system’s requirements, but with some risks. • 4= GOOD: the proposed solution meets the system’s requirements. Subsequently, attributes, weights and scores have been allocated, the quantitative frame which builds a rational evaluation has been defined, calculating the relevant weighted score for each sub-requirement. Figure 13 shows details of the TPM comparison analysis results. Following the outcome of the TPM approach, the results of architecture A of the air distribution system are preferred. Multidisciplinary optimization of air distribution system components The shape optimization of the air vent outlet has been carried out through the following phases: 1. Mesh accuracy study 2. Input sensitivity study 3. Design of Experiment (DOE) Analysis 4. Optimization 5. Automatic updating of the party in the product Design specifications Based on the flow of incoming air assigned to the maximum operative mass flow rate, the shape of the air vent outlet has been optimized (Figure 14) with the objective of minimizing pressure losses and noise levels. To achieve these goals, the geometry for the surface connection between the inlet and outlet of the nozzle has been parameterized.
Among the geometric parameters that were evaluated for the optimization is the angle Alpha; it is important to mention that this angle is formed by the axis coming from the centre of the inlet and the centre of the outlet, it changes the direction in which the air flow enters the cabin. Parameterization For the parameterization 6 points have been identified; these 6 points are located on the intersection of a virtual plane perpendicular to the line joining the centres of the inlet and the exit outlet. The 6 splines in Figure 15 have been initially identified as points A, B, C, D, E, F. As these point change their locations, the area of the opening will be adapted for the purpose of the optimization. Based on this configuration and by changing the location of the points, it becomes possible to update the area of the opening and in this way to modify the purpose of the optimization. modeFRONTIER Model In the modeFRONTIER model the geometric inputs are held constant while varying only the parametric data for the CAE model. The process flow consists of three blocks: 1. CATIA process: it opens the file CatiaV5 CATPart geometry of the nozzle, then it converts files into IGS and sends them to the next process. 2. STAR Process: StarCCM+ runs a mesh with Base Size Length which is assigned to the CAE_Input, then it automatically performs the calculations. It estimates the time taken (CPU_Time), and sends the simulation file (SIMfile) for the next process. 3. Process PostPRO: StarCCM+ checks for the simulation file, and if there are further calculations to determine the pressure and noise levels, in particular, according to the PostPRO_Input, a visual representation is saved in a jpeg file containing the pressure, the speed or noise level, as well as images of the mesh and the graph of the residue. The variables monitored are CPU processing time in seconds, CPU_Time, and total pressures in Pascal in and out of the nozzle: p_in p_out respectively.
Fig. 16 - modeFRONTIER model for shape and noise optimization of the outlets
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Design Of Experiment (DOE) Analysis In modeFRONTIER (whose workflow is shown in Figure 16) a DOE analysis has been performed taking into account the 3 free parameters dx_CF, dy_AB, and dy_DE, while, dx_AB, dx_DE, and dy_CF remain constant or the abscissas of points A, B, D and E. The ordinates of tpoints C and F remain stationary as assigned by the geometry.
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Table 2 - Table of results for optimal pressure and optimal noise reduction based on DOE
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Table 3 - MDO results based on the NSGA-II analysis
The range of variations of the free parametersis as follows: • dx_CF varies from -5 mm to +25 mm in steps of 10 mm (5 mm, +5 mm, +15 mm, +25 mm) • dy_AB ranges from -10 mm to +20 mm in steps of 10 mm (-10 mm, 0 mm, +10 mm, +20 mm) • dy_DE ranges from -10 mm to +20 mm in steps of 10 mm (-10 mm, 0 mm, +10 mm, +20 mm) The challenge of the optimization has been a multidisciplinary and multi-objective problem: the disciplines involved have been fluid dynamics and acoustics, the objectives were minimizing the pressure drop (p_in - p_out) and minimizing the level of noise emitted from outlets and walls.
Fig. 18 - Parallel Coordinates Chart optimization
Fig. 18 - Acoustic analysis for the outlet Fig. 17 - Parallel Coordinates Diagram for the restriction of the domain space of pressure loss and noise
Results A 4 level full factorial DOE has been carried out on the 3 variables, which means that 64 configurations have been tested (43 = 64 experiments). Following are the results which represent a significant improvement to the previously adopted design. The minimum pressure drop (corresponding to the configuration process number 9) and the minimum sound level (corresponding to the configuration process number 59) are shown in Table 2. From the table, it becomes clear that the two objectives cannot be achieved simultaneously, as the minimum pressure drop is far from the minimum level of noise produced by the walls (Table 2). Therefore, the analysis moved on to a Multidisciplinary Design Optimization MDO. Outlet MDO To refine the research of the investigation it has been decided to filter the results by imposing the limits of acceptance for the pressure drop in relation to the level of noise emitted from the walls. The filtering action narrowed the range of variations. This effect is shown in the filters operating diagrams in Figure 17, where the parallel coordinates were
Fig. 19 - Outlet CFD analysis for pressure drop
reduced to a range of 3 to 28 dB noise levels and a maximum pressure drop of 4 Pa. As before, the three parameters that vary have been dx_CF, and dy_AB dy_DE, while the other 3 parameters, dx_AB, and dx_DE dy_CF, remain constant, or the abscissas of points A, B, D and E. • dx_CF ranges from +12.5 mm to +25.0 mm in steps of 2.5 mm • dy_AB varies from -2.5 mm to +12.5 mm in steps of 2.5 mm • dy_DE varies from -2.5 mm to +12.5 mm in steps of 2.5 mm The optimization has been performed by implementing the Non-dominated Sorting Genetic Algorithm II (NSGA-II) with
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22 - Newsletter EnginSoft Year 9 n°4 treatment) of roughly 2 million cells has been constructed. • Boundary condition definition: all operating conditions. In this paper, we show the results of the boundary conditions, they are reported in Figure 20. Furthermore, an internal macro has been developed and embedded into StarCCM+ in order to simulate the physiology of the passenger in terms of heat load and % of humidity released. • Physics model: steady state, KEpsilon with two layers, all Y+ wall treatment, multi-phase model (air/water), segregated flow with radiation model.
Fig. 20 - Simplified CAD model and Boundary condition
10 generations in a population of 8 configurations chosen from the best, previously tested in the DOE analysis. Results The results of the best iteration in minimum pressure drop (corresponding to the configuration process number 130) and in minimum sound level (corresponding to the configuration process number 82) are presented in Table 3.
The aim of the analysis has been the study of the A/C cabin, we have analyzed and verifyied the following parameters: • Velocity field (see Figure 21) • Relative humidity pattern (see Figure 22) • Temperature pattern in cabin zones (see Figure 23). • Cabin average temperature
The Parallel Coordinates in the diagram of Figure 18 illustrate the results for the r80 run configurations generated for the optimization. Figure 18 shows the acoustic FEA analysis, and Figure 19 shows the CFD pressure losses analysis. Evaluation of the A/C cabin thermal environment and the occupants’ thermal comfort Once the design of the air distribution system and of the air conditioning pack were completed, the final steps have been the evaluation of the cabin thermal environment and the passengers’ comfort assessment. This activity has been developed through the following steps: • Tri-dimensional cabin thermal model development. • Assemby of a complete mono-dimensional model. • Comparison between the two approaches. Tri-dimensional CFD cabin thermal model The tri-dimensional cabin thermal model has been developed in the StarCCM+ environment, through the following steps: • Domain definition: due to its symmetry, a 2 meter long section of the cabin has been analyzed. • Mesh construction: in order to study, in adequate detail, the distribution of velocity, temperature and humidity, a polyhedral mesh (with a prism layer for turbulence
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Fig. 21 - Velocity field
Fig. 22 - Relative humidity pattern
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temperature calculated with the CFD analysis is comparable with the average temperature calculated with the mono-dimensional model, assuming the same input conditions. The CFD model allowed to obtain a detailed evaluation of the cabin thermal environment, the temperature stratification, the stagnation zones, and the thermal environment near the passengers for evaluating the status of the passenger comfort. The mono-dimensional thermal model allowed, in a sufficiently accurate way, to obtain a fast evaluation of the cabin thermal environment in terms of average temperature and % of humidity. Fig. 23 - Temperature pattern
Passenger comfort requirements imposed by the aeronautical rules are: • Differential temperature between aft and forward side are not to exceed 2°C • Differential temperature between head and feet are not to exceed 3°C. • Differential temperature between left and right side are not to exceed 2°C. Considering as boundary conditions the data reported in Figure 20, our CFD model provides the following results: • Average relative humidity: 36.37% • Cabin average temperature: 23.8°C • As shown in Figure 23, the compliance with comfort requirements described above could be guaranteed. Complete ECS system mono-dimensional model. The complete mono-dimensional model has been obtained by linking the air conditioning pack model (see Figure 4) with the air distribution system model (see Figure 10), and with the A/C thermal model shown in Figure 6. The aim of the analysis was to study the A/C cabin thermal environment, analyzing and verifying the following parameters: • Average relative humidity • Cabin average temperature The analyses have been performed at different A/C and flight conditions. Considering as boundary conditions the data reported in Figure 20, our mono-dimensional model delivered the following results: • Average relative humidity: 40% • Cabin average temperature: 24.1°C. Results In order to evaluate the mono-dimensional model results (low fidelity model), its results have been compared with the CFD tri-dimensional model results (high fidelity model). The performed analysis has highlighted that the average
Conclusions Various new frontiers are currently emerging in the aerospace industry. They require new initiatives and approaches for the role of engineering design and analysis, mainly due to the profound knowledge of the importance of cross-firms and cross-disciplines collaboration in large scale engineering design processes, such as aircraft design. This kind of collaboration and interaction is now more possible than ever before due to the current state of digitization of engineering design data, an IT infrastructure that enables a universal communication of data, the current engineering platforms which support collaboration, and the increasing computational power, which allows us to integrate multidiscipline, multi-physics and engineering data in one shared environment. This state-of-art design environment is leading to a new opportunity, and to a challenge. As the present study shows, process integration between different design disciplines is an essential factor for automating design processes. The design process presented in this paper is actually used in the Environmental Control System department of Alenia Aermacchi, where fluid dynamic problems are approached with innovative tools and innovative methodologies that allow to define the architecture and to optimize the performance from the early stages of the system design. The described approach allowed to achieve the following reported goals: • Reduction/elimination of physical tests and related costs during the development phase. • Minimization of certification tests. • Minimization of risks and costs linked to the re-design of parts in the manufacturing phase. Alenia Aermacchi S.p.A. – G. Mirra, P. Borrelli, A. Romano Politecnico di Torino – M. Tosetti, L. Pace Università del Salento – B. Palamà, A. Camillò For more information: Francesco Franchini, EnginSoft info@enginsoft.it
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24 - Newsletter EnginSoft Year 9 n°4
How Geometrical Dimensioning & Tolerancing influence the performances of an electromechanical contactor return stable coupling of fixed parts, adequate freedom of moving parts and appropriate room to house electrical parts. For simplicity, we will call “functioning measurements� all those the contactor dimensions from which its reliable operation depends. In other words, if one or more functioning measurements is not comprised between assigned limits, the contactor assembly does not work properly and has to be rejected. Lovato Electric has been a prestigious Italian company operating Generally speaking, overall dimensions (including the in the electromechanical and electronic components market for functioning measurements) of a multi-part assembly depend on more than 90 years. Its wide catalog includes magneto-electric how both surfaces and edges of adjacent parts touch switches, contactors, sensors, digital multi-meters, soft-starters, themselves. From this point of view, the study of the assembly relays, automatic power factor correctors and other devices. Top geometrical properties becomes a tridimensional problem, whose quality, reliability and product variety make Lovato Electric a complexity grows with the number of contacts and shape of the star player in the world market. Company success is gained involved features. If parts had nominal shape, then the through constant valorization of internal competences and assembly would be univocally determined and solved by using parallel effective collaboration with customers and suppliers. any CAD tool. Real assembly conditions are far from the ideal In a past engineering service, EnginSoft was requested by ones, because real geometries exhibit a certain dispersion due Lovato Electric to investigate how the operation of an to the manufacturing processes. As a consequence, the assembly electromechanical contactor is influenced by dimensional and output is no longer univocally determinable and functioning geometrical tolerances of its components (GD&T analysis). measurements become dispersed as well. The contactor designer Electromechanical contactors constitute a relevant fraction of controls and limits the variability of the functional Lovato Electric production, so that the topic was perceived as of measurements (trying to keep them between the acceptance primary importance. limits) by assigning proper An electromechanical contactor is a dimensional and geometrical compact device including an tolerances to the components. The electromagnetic actuator investigation of how tolerances affect mechanically connected to a set of the dispersion of the functioning contacts. When the command signal measurements is carried out through a (a low power current) activates the statistical approach. internal inductor, a piston moves and change the connected contact status. The contactor that has been analyzed in the consulting service is composed Typically, this device is used to break a power circuit from changes by existing parts (i.e. taken from other production lines) and specifically location, without manually accessing designed new parts. EnginSoft the switch. The contactor is contribution has made possible to composed by both plastic and predict both mean values and metallic components held together by dispersions of the 5 functioning snapfeatures and screws. Plastic parts are manufactured by injection dimensions selected by the customer and shown in Figure 1. At the same molding process, while metallic parts time, an extensive sensitivity analysis are manufactured by cold forming of has made possible to identify the sheets. The contactor works reliably if factors influencing these dimensions, the assembly process creates both which are the key information to precise clearances and precise assess corrective strategies in case of interferences between parts, where unsatisfying distribution of the they are necessary. Fig. 1 - Contactor section highlighting the 5 outputs. Indeed, these geometrical conditions functioning measurements
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Newsletter EnginSoft Year 9 n째4 -
The service was completed through different tasks. First, the 3D CAD model was analyzed in detail to understand how the components interact and to select the surfaces involved in the contacts. Then, the dimensional chains were written accordingly. Each dimensional chain provides a vectorial representation of the geometrical relationships between component dimensions and functional measurements. For the analyzed device, it was found that 35 dimensions (among hundreds available) were affecting the functional measurements. As expected, the 5 dimensional chains resulted to be interdependent, since some dimensions were simultaneously included in more than one relationship. At the end of the problem definition, a virtual model of the contactor was developed, and the values of the 5 functioning measurements were calculated. A model used to investigate GD&T problems needs to faithfully reproduce geometrical interactions between parts. In order to meet such requirement, the virtual assembly is performed by putting into contact both surfaces and edges, instead of aligning planes and axes as we normally do in a CAD environment. The hardest phase of such work, which is also the deeper added value of this service, is really the mathematical description of the tridimensional interactions between component features. The model is finally parameterized, so that it includes the variability (in terms of position and size) of all geometrical details involved in the contact definition. Virtual measurements can be taken easily, in accordance to the model purposes. It is not difficult to see that a model with the mentioned characteristics, virtually reproduces any possible configuration of the multi-part assembly. From a different perspective, we could look at the model as to a numerical representation of the dimensional chains previously identified: it correlates the outputs (i.e. the functioning measurements), to the inputs (i.e. the component dimensions). The statistical investigation of the GD&T problem was carried out by assigning a normal distribution to each dimension of the components. This was an arbitrary choice, since we did not have information about. Obviously, we could have assigned any kind of distribution to each dimension. Mean values were picked in the middle of the corresponding tolerance ranges, while standard deviations were assumed as equal to 1/6 of the widths. These assumptions relate to the quality of the manufacturing processes we consider. By filling the tolerance range with 6 standard deviations, we implicitly assume that just 1 component out of every 370 has the considered dimension out of its tolerance. We investigated how tolerance effects propagate to the functioning dimensions, by generating a huge number of device configurations in a limited time. Distributions of the 5 outputs were then compared with the given acceptance limits, in order to identify the percentages of devices fulfilling the requirements. Main results are collected in Figure 2, the distributions of the 5 functioning measurements are compared to the corresponding requirements. All distributions are still of normal type, with symmetric shape. Plots highlight that significant fractions of the entire production are not meeting the operational requirements.
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Fig. 2 - Distributions of functioning measurements in the virtual production
The probability for a contactor to not be accepted after assembly is about 37%, mainly because the measurement n. 4 goes out of its acceptance limits. Plots of Figure 2 shows that non conformities can be caused by both an excessive width of the distribution (FUNC.MEAS.3) or a misalignement of the mean value with the acceptance range (FUNC.MEAS.2 and FUNC.MEAS.4). The statistical sensitivity analysis carried out on the population has made possible to select the dimensions (among the 35 involved) with the highest influence on the 5 outputs. Thus, appropriate adjustments were assessed to reduce the risk of non-conformity. In particular, the mean value of FUNC.MEAS.4 was moved to right (almost making null the area lying out of the acceptance bounds) by adjusting the nominal value of 2 component dimensions. This result really highlights the power of the GD&T analysis: an assembly issue is fixed with no need to narrow tolerance ranges. In other words, the reduction of rejected devices is obtained without increasing manufacturing costs. In this example, the collaboration between Lovato Electric and EnginSoft has returned valuable benefits. EnginSoft has simulated the assembly process through advanced numerical tools, providing crucial information about the relationships between component dimensions and final contactor performances. As issues were identified, proper corrections were planned and verified immediately. This has allowed Lovato Electric to shorten the physical prototyping phase, which turned into an effective reduction of overall production costs. For more information: Fabiano Maggio - EnginSoft info@enginsoft.it
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26 - Newsletter EnginSoft Year 9 n째4
Research Activities on Slot-Coupled Patch Antenna Excited by a Square Ring Slot A novel slot-coupling feeding technique for wideband dualpolarized patch antennas is presented. A square patch is fed through a square ring slot excited by two non-overlapping feeding lines printed on the same side of a single-layer substrate. Reflection coefficient, port isolation and radiation patterns are evaluated by numerical simulations with ANSYS Designer and compared with measurements on an antenna prototype operating at the WiMAXTM 3.3-3.8 GHz frequency band (14% impedance bandwidth). Based on the slot coupled feeding technique, the following antennas have been designed and prototyped: a 2x2 array of dual-feed circularly-polarized square patches, a single-feed circularly-polarized square patch, also in a stacked version, a 2x2 array of dual-polarized circular patches fed through a circular slot, a 2x1 array of stacked square patches fed through square slots. 1. INTRODUCTION The last years have seen a significant exploitation of printed antenna technology in mass production of planar arrays for base stations and subscriber units of cellular communication systems. Indeed, microstrip antennas are characterized by low profile, light weight, easy construction, and high flexibility in designing shaped-beam and multiband antennas. Although there are some considerable concerns regarding the microstrip antenna inherently resonant feature, a number of efficient techniques have been proposed to meet the large impedance bandwidth requirement of modern broadband communication systems. Furthermore, several dual-polarized patch
Fig. 1 - Some configurations of dual-polarized slot-coupled patch antennas, with different positions of the two coupling slots with respect to the patch center. Feeding lines with the same color are printed on the same side of the dielectric slab; in X1 an air bridge is needed to avoid line overlapping.
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configurations have been designed to be used as radiators in arrays for polarization-diversity based radio links. A common feeding technique for wideband antennas is based on slotcoupling, where a microstrip line is coupled to the radiating patch through a slot in a metallic ground plane, as first proposed by D.M. Pozar. Slot-coupled patches can exhibit a quite large impedance bandwidth at the cost of an affordable construction complexity, and allow for more space for the feed network with respect to microstrip fed arrays (the latter being an important need especially for dual-polarized dense phased arrays). Moreover, the metallic slot plane prevents the spurious radiation from the feed network and then reduces the amplitude of the cross-polar components. Finally, the two-layer structure allows for using a thick low-permittivity substrate for the patch (which guarantees a larger impedance bandwidth and a higher efficiency) and a thin high-permittivity substrate for the feed circuitry (as required to suppress radiation from the feed line and to save space for the feed circuitry). To extend the singlefeed, single-polarization design to the dual-polarization antenna design, a large number of aperture-coupled patch antennas have been presented in the open literature (most of them are shown in Figure 1). Dual-polarized microstrip antennas require the excitation of the two orthogonal fundamental modes of a microstrip patch. Dualmode excitation can be obtained by coupling the radiating patch to the feeding network through two orthogonal slots in a metallic ground plane: either a cross-shaped slot or separated orthogonal slots have been used. Besides gain and radiation pattern values, design concerns are also about the port isolation and the cross-polarization level, since they impact on the communication system performance. Both above properties are markedly related to the electrical and the geometrical symmetry properties of the antenna layout with respect to the principal radiation planes. Moreover, a symmetry property of the antenna with respect to the two input ports is also a valuable feature, as in this case the two polarization ports exhibit identical impedance and radiation characteristics. In this paper a novel dual-polarized slot-coupled feeding technique is presented. With respect to other slot-coupling feeding techniques for dual-polarized patch antennas, the proposed configuration exhibits a simple structure and a valuable
Newsletter EnginSoft Year 9 n°4 -
symmetry property with respect to the two feeding ports, while preserving a satisfying isolation between them (greater than 20 dB). A square patch is coupled to a pair of microstrip feeding lines by a square ring slot realized in a metallic ground plane, and both feeding lines are printed on the same side of a singlelayer substrate. Antenna layout performance is shown for a design relevant to a patch operating in the 3.3-3.8 GHz WiMAXTM frequency band. Simulation data agree with measurements on an antenna prototype. The proposed coupling technique is suitable for the design of large planar arrays with dual linear polarizations (vertical/horizontal polarizations or 45° slanted polarizations). Dual circular polarization can also be implemented by adding a 90° hybrid coupler. ANSYS Designer is the electromagnetic simulator code used for all patch antennas design. The physical quantities taken into account in all projects are the reflection coefficient, the isolation between the two channels in the dual polarization configurations, the axial ratio for circular polarized antennas, the gain and directivity, the 3D radiation patterns and the Eθ and Eφ components in the two principal antenna planes, the back radiation, the side lobes level. Each antenna element is parameterized in order to analyze each parameter effect on the antenna performance and in order to simplify the optimization process. For example, thanks to the parameterization, modifying the distance between two array elements elements is not necessary to re-design the feeding network. The simulated results are very close to the prototype measurements, also avoiding systematic errors that are committed in the measurement process, as implementation prototype errors, welds discontinuities, etc. The article is organized as follows. The novel slot-coupling feeding technique and its working principle are illustrated in Section 2 together with simulated results obtained with a fullwave commercial tool and with measurements on an antenna prototype. Section 3 describes the new feeding technique applications to some circular polarized arrays and stacked antenna. Finally, concluding remarks are drawn in Section 4. 2. A Square Ring Slot Feeding Technique The novel dual-polarized slot-coupled patch antenna fed through a square ring slot is shown in Figure 2. Both feeding lines are printed on the same side of a single layer substrate and a metallic reflector is added to limit the back radiation. It is apparent that the layout is symmetric with respect to the two input ports, which means that identical radiation and input impedance properties are expected. The latter represents a useful feature when designing a circular polarized patch (requiring an additional feeding circuit to generate two signals with the same amplitude and a 90° phase shift), or when designing the feeding network of a dual-polarized array. Moreover, since the slot and patch phase centers overlap, the radiation pattern main direction is not depointing at any frequency. The radiating elements are fed in ANSYS Designer through an edge port inserted between the microstrip line (printed on the dielectric substrate upper surface) and the antenna ground plane (on the other side of the same substrate). The proposed
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Fig. 2 - The square patch fed through a square ring slot: (a) stackup and (b) layout. Dimension of the geometrical parameters for a 3.5 GHz WiMAXTM antenna: P=22 mm, L=17 mm, K=0.5 mm, W1=2.5 mm, W2=3.7 mm, S1=2 mm, S2=6 mm, H1=22 mm, H2=11 mm.
feeding technique allows to simultaneously feed the patch by using two orthogonal microstrip lines, furthermore the above lines can be properly connected to get circular polarization. To evaluate the isolation between these two channels and to analyze separately the Eθ and Eφ components contribution generated by the two microstrip lines, it was necessary to insert two edge ports. To show the working principle and the radiation properties of the proposed slot-coupled patch, a sample antenna operating at the 3.3-3.8 GHz WiMAXTM frequency band has been designed, fabricated and characterized. It is worth noting that the proposed geometry can be used for any application requiring a planar dual-polarized antenna with a 10-15% fractional bandwidth (larger impedance bandwidth can be also obtained by adding a square stacked patch) and a 20 dB port isolation. In the sample antenna, both microstrip lines are printed on the same 90x90 mm2 Rogers RO4003 laminate (εr=3.55, tanδ=0.0027, thickness=1.524 mm), available in the ANSYS Designer material library. The low loss Roger RO4003 used for the antenna active part, although more expensive, allows to obtain higher antenna gain thanks to lower feeding line losses. Instead, the low cost FR4 was used to print the patches, electromagnetically coupled to the microstrip line. The stackup is shown in Figure 2a. The square ring slot has a perimeter of 68 mm (Figure 2b) and it is etched on the other side of the above substrate, namely on the metallic ground plane separating the feed lines from the square patch. As in other slot-coupled patch configurations, the ground plane prevents spurious radiation from the feed network and the length of the open-circuited stub behind the slot is optimized for input impedance tuning. A 160x160 mm2 square aluminum reflector is placed at a distance of 22 mm from the feed lines to reduce back radiation and increase the antenna gain. The 22x22 mm2 copper patch is printed on the bottom layer of a 90x90 mm2 FR4 laminate, which is 1.6 mm thick (it also acts as a cover for the antenna). The air gap between the patch and the slot plane is 11 mm thick. Figure 3 illustrates the electric field distribution inside the square ring slot when Port1 of the patch in Figure 2 is fed. It is apparent that the field distribution resembles that of the fundamental resonating mode of a ring slot. This is in agreement with the slot perimeter length that is close to the guided wavelength λg of a slotted line with the
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28 - Newsletter EnginSoft Year 9 n°4 same geometrical and electrical parameters as those of the slot: Oviedo. The frequency set for the mesh was thus chosen as 5 λg=66 mm at 3.5 GHz. The electric field distribution shown in GHz, which was a good compromise between mesh accuracy and Figure 3 reveals a number of interesting features. The side of simulation times (Figure 5). The sweep analysis was varied from the ring slot that is directly fed and that one parallel to it (i.e. 3000 to 4000 MHz. the vertical sides of the ring slot shown in Figure 2b) are both excited, and the electric field induced into the two slot sides Both measured and Designer simulated results for the reflection are in phase and with a similar amplitude; as a consequence, coefficient and port isolation are shown in Figure 6, and they due to above phase relationship and the symmetric position of exhibit a reasonable agreement. For both polarizations, the the vertical sides with respect to the reflection coefficient is less than -10 dB, patch center, the resonant mode of the from 3.3 GHz to 3.8 GHz (percentage patch (that one associated to Port1) is impedance bandwidth is 14%). The port properly excited and low crossisolation is greater than 20 dB in the whole polarization is expected. Moreover, the 3.5 GHz WiMAXTM frequency band. electric field distribution induced into the In Figure 7, the co-polar and cross-polar two sides of the slot orthogonal to the components of the radiation patterns, in the previous ones (i.e. the horizontal sides of θ=45° and θ=-45° radiation planes, are the ring slot shown in Figure 2b) are out shown, when Port2 is fed (indeed, dual-linear of phase and do not excite the orthogonal polarized antennas are usually used to resonant mode of the patch (that one Fig. 3 - Direction and amplitude of the electric implement base station antennas with ±45° associated to Port2). Finally, the induced field inside the square ring slot, when Port1 of slanted polarizations). Measured half power electric field does vanish close to the the antenna in Figure 2 is fed (ANSYS Designer beamwidth at 3.55 GHz is around 56° in both data). center of the horizontal sides of the slots; planes and cross-polar components are below
Fig. 4 - A square ring slot antenna prototype for 3.5 GHz WiMAXTM applications.
Fig. 5 - Antenna mesh at 5 GHz.
it means that a relatively high port isolation is expected when that point is used to couple the slot ring to the orthogonal feed line corresponding to Port2. It is worth noting that since the slot perimeter is less than the free-space wavelength (actually it is around a slot-line guided wavelength) and the patch perimeter is almost double the free-space wavelength, the whole square ring slot does always remain under the patch, for any design frequency. Finally, due to the perfect symmetry between the two ports, the same radiation patterns (in both E and H planes) and the same gain for the two ports are expected in the whole antenna frequency bandwidth. The presented novel layout can be seen as an advancement of “O” configuration in Figure 1. Indeed, it is apparent that the four-slot arrangement, symmetric with respect to the patch center, resembles the ring slot geometry. The significant difference is that in the novel configuration all four sides of the ring slot contribute effectively and correctly to the excitation of the two orthogonal fundamental patch resonant modes, while in the “O” configuration two of the four slots are parasitic elements. A 3.5 GHz WiMAXTM prototype (Figure 4) has been realized and measured in the anechoic chamber at the Department of Electrical Engineering of the University of
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Fig. 6 - Measured and simulated S-parameters of the square ring slot patch.
-18 dB in the broadside direction. Measured gain is between 8 dB and 8.7 dB in the band of interest (Figure 8). Similar results are obtained when Port1 is fed. 3. Square Ring Slot Technique Applications Basing on the ring-slot coupled feeding technique, the following antennas have been designed and prototyped: a 2x2 array of dual-feed circularly polarized square patches (Figure 9), a single-feed circularly polarized square patch, also in a stacked
Fig. 7 - Measured and simulated co-polar and cross-polar components for the square slot patch in Figure 2, at f=3.55 GHz when Port2 is fed: (a) θ=45° plane and (b)θ=-45° plane.
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version (Figure 10), a 2x2 array of dualdesigned to increase the percentage polarized circular patches fed through a bandwidth up to 44.5% in order to be circular slot (Figure 11), a 2x1 array of used at base stations where wideband stacked square patches fed through square antennas are needed (e.g. base stations slots (Figure 12). In Figure 9, the sequentially for GSM, PCS, UMTS, WLAN applications). rotated 2x2 array prototype with a complete The simulation times, for all the microstrip feeding network is shown. Each antennas designed and presented in this dual-linear polarized patch has been fed paper, vary between 15 and 60 minutes, through a reactive 3 dB power divider in order depending on the antenna operating to have a single feeding line. The feeding band and the radiating elements number network consists of microstrip lines whose Fig. 8 - Measured and simulated gain of the in the configuration. The ANSYS Designer square ring slot patch in Figure 2, when Port2 lengths have been adjusted to achieve the is fed. simulation process has saved a lot of required 90° current phase difference time: the prototype procedure (up to between adjacent elements. To get a wide impedance and wide connectorization process) and measured process is very axial ratio bandwidth, a sequential rotation feeding technique onerous: the prototype process was about 60 minutes, the has been adopted. A single feed slot-coupling solution has radiation patterns measurements component for a single plane been applied to gain circular polarization. A meandered slot is at a single frequency was about 2 minutes). Then this procedure designed to excite two orthogonal modes and the same kind of was repeated for each plane, both the components and the perturbation is applied to the patch. To preserve the antenna entire band of interest. Moreover, it is necessary to take symmetry, two identical meanders have been added on two account of the entire prototyping and measurement cost (the opposite sides of the square ring. Both width and length of the materials cost, the instrumentation, the available facilities). It above slots have been optimized. To improve axial ratio was therefore fundamental to get to the measurement stage performance, a stacked solution has been proposed (Figure 10) with reliable projects, obtained with ANSYS Designer. to get a 12% 3 dB axial ratio bandwidth. Basing on Figure 9, the configuration shown in Figure 11 is 4. CONCLUSIONS designed with both circular slot and patch. The performances of A novel wideband slot-coupled patch fed through a square ring the two configurations are shown and compared for two slot has been presented and design criteria have been fabricated prototypes. Antennas shown in Figure 9 and Figure discussed. Owing to its simple structure, the patch described 11 have been designed to operate in the WiMAXTM frequency here can be used as the radiating element of medium and large band around 3.5 GHz. The configuration shown in Figure 12 is planar arrays with dual linear polarizations (vertical/horizontal a 2x1 array of square stacked patches. This antenna has been polarizations or ±45° slanted polarizations). Antenna performance in terms of port isolation and cross-polar component level has been shown through the design, fabrication and characterization of a patch operating at the 3.3-3.8 GHz WiMAXTM frequency band. A 20 dB port isolation has been obtained, in a 500 MHz frequency band (14% fractional bandwidth), with cross-polar level less than -18 dB at the broadside direction. We have also experienced that the final design of the proposed solution is a result of a trade-off between frequency bandwidth enlargement and isolation improvement. Impedance bandwidth enlargement can be Fig. 10 - Single-feed circularly polarized achieved by adding either stacked patches or other parasitic Fig. 9 - 2x2 array of dual-feed stacked square patch for 3.5 GHz circularly polarized square patches elements close to the main radiating patch, while preserving WiMAXTM applications. for 3.5 GHz WiMAXTM applications. the original symmetry properties. Finally, due to the symmetry of the antenna layout with respect to the two feed ports, good axial ratio performance can be obtained when it is used to radiate a circularly polarized field.
R. Caso, A. Buffi, P. Nepa - Department of Information Engineering, University of Pisa A. Serra - EnginSoft Fig. 11 - 2x2 array of dual-polarized circular patches fed through a circular slot for 3.5 GHz WiMAXTM applications.
Fig. 12 - 2x1 array of stacked square patches fed through square slots for GSM, PCS, UMTS, WLAN applications.
For more information: Andrea Serra, EnginSoft info@enginsoft.it
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30 - Newsletter EnginSoft Year 9 n째4
Grapheur for Material Selection In this article the criteria of mechanical behavior of the MCDM for Material selection woven textile composites during the draping and the further When multiple criteria from different disciplines are to be involved simulations and analysis are included in the process satisfied in a material selection problem, often complexities of the optimal design and decision making. For this purpose, the advanced software architecture of Grapheur for interactive optimization and MCDM is utilized. In this software the identified challenges of utilizing MCDM are improved via connecting the data mining/visualization and optimization through the user interaction. For the optimal Fig. 1 - Simulation of the draping process design of composites, with the aid of advancement of interdisciplinary and data analysis tools, a series of criteria including mechanical, electrical, chemical, cost, life cycle assessment and environmental aspects aspects can now be simultaneously considered. As one of the most efficient approaches, the MCDM applications can provide the ability to formulate and systematically Fig. 2 - A combination of four different simulation criteria including the compression, bend, compare different alternatives against the large stretch, and shear form the draping a) Mechanical modeling of the bending; the behavior of sets of design criteria. However, the mechanical textile under its weight is simulated by manipulating the related geometrical model within behavior of woven textiles during the draping the CAGD package. b) Geometrical model increase due to criteria conflicts. Many applications and process has not yet been fully integrated into the optimal algorithms of MCDM have been previously presented to deal design approaches of the MCDM algorithms. with decision conflicts often seen among design criteria in material selection. However, many of the identified Introduction In the integrated engineering design process and optimal drawbacks and challenges are associated with the applicability. design, the material selection for the composite can determine the durability, cost, and manufacturability of final products. The process of material selection begins with Draping indentifying multiple criteria properties of mechanical, The manufacturing of woven reinforced composites requires a electrical, chemical, thermal, environmental and life cycle forming stage so-called draping, in which the preforms take costs of candidate materials. However, the mechanical the required shapes. The main deformation mechanisms behavior of woven textiles during the draping process has during forming of woven reinforced composites are not yet been fully integrated into the optimal design compression, bend, stretch, and shear which cause changes approaches of the MCDM algorithms. in orientation of the fibers. Since fiber reorientation
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Newsletter EnginSoft Year 9 n째4 -
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Fig. 3 - Geometrical modeling of double dome utilizing the Khabazi [11] algorithm.
influences the overall performance, it would be an important factor that should be taken into account along with the other criteria. Mechanical modeling and simulation of the draping The mechanical models of drape involve much higher computational cost when compared to the kinematic models; yet, they offer the benefit of representing the non-linear material behavior. Moreover the mechanical simulation, as the most promising technique, gives a real-life prediction of the fiber reorientation. Geometrical modeling and simulation of the woven textiles Moreover, of all the approaches for the geometrical modeling of woven textiles presented so far, the Spline-based methods are the most effective technique. In fact, the Spline-based geometrical representation of a real-life model of any type of flat-shaped woven textile, is realized by implementing the related computer-aided geometrical design (CAGD) code. However, the mathematical representation of a woven multiple-dome shape, in the practical scale, may not be computationally valid. In order to handle the computational complexity of geometrical modeling the multiple-dome woven shapes, utilizing the NURBS-based CAGD packages are essential. Khabazi introduced a generative algorithm for creating these complex geometries. His improved algorithm is capable of producing the whole mechanism of deformation with combining all details of compressed, bended stretched and sheared properties. It is assumed that if the mechanical behavior of a particular woven fabric of a particular type and material is identified then the final geometrical model of the draping could be very accurately approximated. In this
technique the defined mechanical mechanisms of a particular material, in this case glass fiber, is translated into a geometrical logic form integrated with the NURBS-based CAGD package through a process called scripting. Integration the MCDM-assisted material selection with draping simulation In order to select the best material of a woven textile, the draping simulation needs to be carried out for a number of draping degrees. The results of all the draping simulations of different drape angles are gathered as a data-set for consideration, in addition to already existing data-sets from the earlier study case, including the latter criteria i.e. mechanical, electrical, chemical, cost, life cycle assessment and environmental. Visualization; an effective approach to MCDM and material selection Visualization is an effective approach in the operations research and mathematical programming applications to explore optimal solutions, and to summarize the results into an insight, instead of numbers. Fortunately, during the past few years, huge developments in combinatorial optimization, machine learning, intelligent optimization, and reactive search optimization (RSO) have taken place, which have moved advanced visualization methods forward. Previous work in the area of visualization for MCDM allowed the user to better formulate the multiple objective functions for large optimization runs. Alternatively, in our research utilizing RSO, which advocates the learning of optimization, the algorithm selection, adaptation and integration are done in an automated way and the user is kept in the loop for subsequent refinements. Here, one of the crucial issues in MCDM is to critically analyze a mass of tentative solutions
Fig. 4 - Mechanical modeling of draping process for a number of draping degrees
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32 - Newsletter EnginSoft Year 9 n°4 design, modeling, and decision-making. The software has implemented a powerful interface between a generic optimization algorithm and decision maker. While optimization systems produce different solutions, the decision maker is pursuing conflicting goals and tradeoff policies represented on the multi-dimensional graphs. Conclusions The utilization of a software architecture for MCDM, including the mechanical modeling of the draping, with a particular emphasis on supporting flexible visualization has been discussed. The applicability of the software can be easily customized for different problems and usage contexts. The preliminary tests of the software environment, in the context of designing a multiple dome shape, have shown the effectiveness of the approach in rapidly reaching a design that meets the expectations of the decision maker.
Fig. 5 - a) Parallel chart considering five optimization objectives b) The 7D visualization graph
which are visually mined to extract useful information. Concerning the solving of the MCDM problems, the final user is not distracted by technical details, but instead concentrates on using his expertise and informed choice for the large number of possibilities. Software architecture of the proposed reactive and interactive MCDM The proposed software is based on a three-tier model, independent from the optimization package, called Grapheur which is an effective and flexible software architecture for integrating problem-solving and optimization schemes into the integrated engineering design processes and optimal
Amir Mosavi, Miklos Hoffmann, Atieh Vaezipour University of Debrecen, Hungary
LIONsolver by Reactive Search Srl: the "Big Data" challenge and opportunity Nowadays, more and more enterprises can afford to enlarge their data storage means at will. Information that a few years ago would have been thrown away is now kept in the main storage area, ready to be retrieved and analyzed. Enterprises are now discovering that they lack the means to draw insights from this large amount of data: while storage room builds up nicely, communications and processing power needed to extract useful information from data is beyond their reach. Such power is now made available thanks to parallel processing platforms such as Apache Foundation’s Hadoop, however their use remains a big challenge for most organizations. The LION difference: machine learning and optimization Consider a web server farm as used by many enterprises. Every webpage accessed by a visitor results in the addition of a line of text to a log file recording the instant of of the request, its source, and many other pieces of information (similar logs are produced by activity in social networks like Twitter, Facebook, etc). Server logs keep growing and, to avoid unusably large files, they are broken into smaller files and eventually moved to different disks. When the LIONsolver machine learning and optimization platform is combined with a Hadoop implementation for web log analysis, previously unknown patterns emerge that show the behavior of customers in a website. For example, event data,
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such as video views, email registrations, or literature downloads can be correlated to engagement (time on site), pages visited and interacted with (suggesting the efficacy of web design) and ultimately with purchase follow through. As shown below, LIONsolver drives the flow of data and computation in the Hadoop system, visualizes the results once they are made
available by the framework, develops models by "learning from data" and suggests improving strategies. LIONsolver goes beyond simple visualizations to show correlations that impact business decisions to inform customer and content targeting, web design, business rules, and so on. For more information, visit http://lionsolver.com/ or contact us at info@lionsolver.com.
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Studio di fattibilità produttiva attraverso simulazione numerica di processo di forgiatura Nello studio di processo di produzione per deformazione a caldo di una forcella in acciaio C25 è stato affrontato anche il problema della resistenza a frattura duttile degli stampi. Eseguendo una preventiva analisi del processo di produzione di una Forcella, è stato possibile valutare l’influenza dei diversi parametri dell’intero processo produttivo, successivamente sono state condotte analisi FEM delle diverse fasi di progetto per poter definire gli stati tensionali e deformativi del materiale in deformazione e degli stampi, mediante codice numerico. Si sono potute così valutare le diverse cause del fenomeno di bassa durata produttiva degli stampi, calcolando i valori di intensificazione delle tensioni nei punti in cui nella realtà si verifica l’innesco della cricca. E’ stata inoltre studiata l’ottimizzazione dell’intero processo, per ottenere un prodotto integro da difetti, un miglioramento del comportamento a fatica degli stampi ottenendo benefici produttivi sia economici che energetici. Introduzione I processi di lavorazione per deformazione plastica sono un campo di estremo interesse per le moderne tecniche CAE vista la complessità teorica dei singoli processi e l’influenza dei vari parametri. In particolare il processo di deformazione a caldo di acciaio in stampi chiusi è stato storicamente uno dei primi processi investigati attraverso le tecniche di simulazione numerica. Ciò soprattutto per l’elevato grado di ripetibilità della “massiva” produzione di dato processo e dei numerosi parametri in gioco. Un approccio di tipo FEM (Finite Element Method) è il più adatto allo studio del processo nel suo dettaglio, con la possibilità di previsione delle tensioni e delle deformazioni indotte dalla lavorazione per deformazione plastica a caldo. L’applicazione di tale metodologia è assai complessa, vista la non linearità di comportamento del materiale che viene schematizzato con un modello elasto-visco-plastico. Il problema che il tecnologo di produzione si trova ad affrontare è quello di definire le diverse fasi di stampaggio per trasformare il disegno del pezzo finito nel disegno del grezzo e della
cavità degli stampi, con un procedimento che segue diverse fasi di progetto. Lo stampaggio prevede un ciclo di lavoro molto complesso, con aspetti che richiedono competenza scientifica ed esperienza per la definizione delle diverse fasi in maniera corretta sia per l’ottenimento di un corretto manufatto esente da difetti, sia nella scelta della soluzione più economica. Lo studio condotto si prefigge l’obiettivo di dare un contributo significativo allo sviluppo di tecniche per la progettazione e l’ottimizzazione dei processi di lavorazione per deformazione di acciai. L’intero progetto ha lo scopo di poter migliorare il controllo del processo di deformazione, l’analisi delle difettosità, delle forze e delle sollecitazioni a fatica degli stampi su base ripetibile in ambiente produttivo della moderna realtà industriale. Il componente forgiato preso in esame è una forcella, organo meccanico di collegamento atto alla trasmissione di forze statiche e dinamiche, prodotto in tre passaggi: Preformatura, Abbozzatura e Finitura. Nella prima parte dell’attività si è esaminato lo stato dell’arte del processo di produzione del particolare preso in considerazione, conducendo studio FEM del processo reale: studio della parte “teorica” di processo, introduzione ed approfondimento delle basi della fisica, meccanica e strutturale per comprendere le dinamiche della deformazione plastica a caldo di un materiale metallico, le metodologie e le operazioni che li caratterizzano. Nell’ultima fase di stampaggio, Finitura, dopo un numero esiguo di prodotti, si riscontra nella realtà produttiva il fenomeno di rottura dello stampo superiore in una regione ben localizzata di concentrazione degli sforzi. Lo studio si è focalizzato sull’analisi di tale fenomeno, il quale inficiava la produttività reale del processo, ponendosi l’obiettivo di minimizzare il carico pressa necessario alla deformazione, e ottimizzare il binomio processo/prodotto variando le condizioni a contorno, nel pieno rispetto dei vincoli di completo riempimento e nulla difettologia sul forgiato finale.
Case Histories
34 - Newsletter EnginSoft Year 9 n°4 L’ottimizzazione è stata condotta sull’intero processo, concatenando le diverse operazioni di forgiatura intimamente accoppiate con l’evoluzione termica del componente in deformazione e nelle fasi intermedie di passaggio da una all’altra operazione. I risultati hanno permesso di correlare la variazione dei principali parametri di processo ai benefici ottenuti: risparmio di materiale (benefit economico) e diminuzione di onerosità di processo (benefit energetico-economico-ecologico). Nella parte finale dello studio, ci si è concentrati nell’analisi di sollecitazione degli stampi con approccio disaccoppiato. Si è testato attraverso analisi FEM, dapprima la riproduzione di sollecitazione e plasticizzazione dello stampo nelle aree di innesco rottura, con verifica del numero di cicli e previsione di vita utile prima di arrivare a rottura duttile; in un secondo momento si è testato come le condizioni di ottimo apportassero significative migliorie anche al fenomeno di “rottura a fatica”. Processo di deformazione plastica a caldo Le lavorazioni per deformazioni plastica di materiali metallici hanno origini lontanissime nella storia della tecnica. Sottoposto all’azione di forze esterne tramite presse o magli, il materiale varia permanentemente la sua forma originale; tale trasformazione avviene allo stato solido-viscoso. I processi di lavorazione per deformazione possono essere suddivisi in: • primari, utilizzando materiale da fusione e ottenendo semilavorati commerciali destinati ad uso diretto o ad ulteriori deformazioni; • secondari, da prodotti di deformazione primaria si ottengono manufatti di forma e dimensioni finite.
stampaggio a caldo è una tipica lavorazione per produzione di grande serie. Di contro lo svantaggio è quello di necessitare di energia per il riscaldo, favorire l’ossidazione del metallo ed inoltre risulta difficile prevedere la precisione dimensionale ottenibile. La billetta iniziale è uno spezzone quadro (sezione 120x120 mm, raccordo R20, lunghezza 327 mm, peso 36 kg) proveniente da deformazione primaria, in C25/1.0406, il volume della billetta
Fig. 2 - Bielletta iniziale in C25. Forcella Forgiata - Prodotto Finito
tiene conto anche della maggiorazione della percentuale di perdita di materiale per ossidazione (calo termico); mentre il prodotto finale di forgiatura è una forcella di trasmissione meccanica (Fig.2). Lo spezzone di acciaio viene riscaldato in forno con lo scopo di arrivare alla temperatura idonea di stampaggio, che deve essere la più alta possibile, rimanendo tuttavia distante dal punto di La corretta progettazione dello stampaggio deve assicurare un fusione per evitare liquefazioni e bruciature di materiale: circa corretto e completo riempimento degli stampi, studiandone i parametri ed i fattori che lo influenzano: 1250°C. Tale temperatura deve essere maggiore di quella critica di transizione vetrosa per poter sfruttare la migliore deformabi• deformabilità e resistenza allo scorrimento; lità, il materiale a tale temperatura ha una caratteristica elasto• uso di lubrificanti; • temperatura della parte deformabile e degli stampi; visco-plastica. Il tempo che intercorre dall’uscita forno al primo step di deformazione provoca una caduta termica della superfi• forma del pezzo finale; • calcolo della forza necessaria. cie della billetta che scambia calore con l’aria circostante (minimizzazione del tempo di fuori forno). Nella maggior parte dei casi di processo di stampaggio è necesI processi di deformazione a caldo avvengono ad una temperasario deformare progressivamente il materiale di partenza, per tura maggiore della temperatura critica di ricristallizzazione, i garantire un riempimento accurato degli stampi e per ottenere vantaggi di tale metodo sono sia le minori forze e potenze riuna valida distribuzione delle fibre all’interno del prodotto finachieste, sia la possibilità di indurre grandi deformazioni e l’ottele. La non uniformità di deformazione influenza negativamente nimento di forme anche complesse, grazie alla maggior duttilità le caratteristiche meccaniche finali dello stampato, per cui eledei metalli alle alte temperature (Fig1). Limitando le forze nevata cura va profusa nello studio dell’intero processo. Spesso si cessarie e sfruttando la migliore deformabilità del materiale, lo necessita quindi di sbozzati intermedi la cui forma e dimensione è mediata tra lo spezzone iniziale e lo stampato finale, attraverso stampi sbozzatori, con caratteristiche simili a quelli finitori, possono essere ottenuti tali sbozzati. Il processo industriale reale è uno stampaggio in tre fasi deformative: Preforma, Abbozzatura e Finitura. Tutte e tre le fasi di Fig. 1 - Deformazione Plastica di un Materiale metallico e proprietà. Effetti dell’incrudimento sulle stampaggio sono ottenute dall’azione della caratteristiche meccaniche. Effetti della temperatura sulle caratteristiche meccaniche di un materiale Pressa Meccanica (Fig.3) che impartisce il metallico.
Case Histories
Newsletter EnginSoft Year 9 n°4 -
Fig. 3 - Pressa Meccanica. Sx Schema di una pressa meccanica ad eccentrico. Dx Cinematismo Biella-Manovella
cinematismo. La pressa meccanica utilizzata nel processo industriale analizzato ha le seguenti caratteristiche cinematiche: Raggio di manovella = 100 mm, Velocità di rotazione = 55 rpm, Rapporto (raggio di manovella)/(Lunghezza di biella) = 0.14285. L’organo mobile con un moto alternativo esercita una forza sul materiale da deformare, durante la sua corsa attiva fino al Punto Morto Inferiore. In tale punto di lavoro la forza disponibile tende all’infinito, ma i costruttori limitano con dispositivi di protezione, la forza massima esprimibile in deformazione ad un valore detto nominale. La forza richiesta dal processo di deformazione deve essere sempre inferiore a quella disponibile. La prima deformazione è in gergo una tipica ricalcatura dello spezzone per discagliatura successiva al riscaldamento in forno ed un miglior posizionamento all’interno della sagoma della stazione di deformazione successiva. La billetta deformata viene collocata sullo stampo inferiore di Abbozzatura, in modo da poter coprire il più possibile il vuoto ricavato nello stampo, e quindi la figura da dover ottenere. In questa seconda fase, al contrario di quella di Ricalcatura in cui gli stampi sono piani, il materiale deve riempire il vuoto fra gli stampi, e quindi deve scorrere sulla loro superficie sotto l’azione della Pressa Meccanica che impartisce il cinematismo. La fase di Abbozzatura presenta un posizionamento della billetta ricalcata che non è univoco, infatti non sono state predisposte sullo Stampo Inferiore delle staffe di appoggio e trattenimento della billetta deformata proveniente dalla fase di Ricalcatura. E’ stata fatta la scelta di posizionare la billetta in modo che la superficie superiore coincidesse con la fine della superficie cava dello stampo inferiore, il robot antropomorfo ha un errore trascurabile nella determinazione di tale posizione. A fine deformazione l’abbozzato ha una forma moto simile a quella del prodotto finito, ma, in questa fase di deformazione, naturalmente, non viene richiesto né un riempimento ottimale né l’assenza di difetti, quali ripieghe. L’abbozzato viene tolto dalla cavità degli stampi tramite l’ausilio di un apposito estrattore, il manipolatore lo posiziona nella cavità dello stampo finitore; avendo una forma molto simile la figura riesce ad auto centrarsi per gravità nella posizione corretta desiderata. Sotto l’azione della stessa Pressa Meccanica, il manufatto viene portato a dimensioni nominali di progetto, il fi-
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nito rispetta la condizione di completo riempimento degli stampi, non presenta difetti nelle parti in cui non possono essere tollerati nella qualità di produzione ed ha un’altezza di bava pari a 5 mm. Il finito di stampaggio verrà successivamente sottoposto al processo di eliminazione della bava, sempre in linea quindi a caldo, trattamento termico, pulitura superficiale, coniatura e controllo prima di essere inviato alle macchine utensili per le lavorazioni per asportazione di truciolo. Sebbene il processo non presenta difetti di stampaggio, si nota prima di tutto che il materiale iniziale utilizzato per lo spezzone di billetta potrebbe essere minimizzato, visto il peso rilevante occupato dalla bava; secondariamente, in ordine di tempo ma non di importanza, si evidenzia come dopo un numero di cicli esiguo per una larga produzione di serie si arrivi alla rottura degli stampi. Studio di Processo attraverso Analisi FEM Lo studio del processo reale è stato condotto attraverso codice numerico che permettesse dapprima di poter definire tutti i parametri di processo e poi poterne studiare, secondo la loro variazione, le influenze nel processo stesso. E’ stato implementato l’intero ciclo di stampaggio partendo dalla billetta fredda dimensionata secondo progetto reale ed il suo inserimento in forno, fino alla completa deformazione in fase di Finitura; nel Codice Numerico è stato implemento un chaining delle varie fasi di stampaggio, in modo da poter automaticamente far calcolare l’intera sequenza e seguire in essa l’evoluzione del comportamento del materiale in deformazione, con particolare attenzione alla termica del processo, alle tensioni ed alle sollecitazioni. La modellazione del processo nelle sue diverse fasi prevede non solo quella geometrica, di facile implementazione con i moderni CAD, ma anche quella fisica, in cui il materiale, la termica ed i contatti rivestono ruoli primari. Il materiale della parte deformabile è descritto tramite il modello di Hansel Spittel (Fig.4), mentre gli stampi in ogni fase di stampaggio sono considerati come elementi indeformabili, infinitamente rigidi ed a temperatura costante (temperatura a regime). Lo scambio termico è definito in modo da descrivere il fenomeno sia quando la billetta è a contatto con gli stampi (αT = 2.0e+04 W/m²°K; effus = 1.176362e+04), sia quando non lo è e quindi scambia calore con l’ambiente circostante (αText = 10.0e+00 mW/mm/°C); per la velocità di esecuzione di proces-
Fig. 4 - Coefficienti del modello di Hansel Spittel del C25/ 1.0406
Case Histories
36 - Newsletter EnginSoft Year 9 n°4 so di deformazione alla pressa meccanica, ci si aspetta che l’influenza dello scambio termico sia di bassa rilevanza tra i diversi parametri in gioco. Attraverso la Legge di Coulomb-Tresca, l’attrito è stato definito in maniera conforme alla realtà dei diversi setup delle fasi di processo reale; in fase di abbozzatura non viene interposto alcun lubrificante, mentre le fasi successive di abbozzatura e finitura hanno una lubrifica spinta per poter far scorrere il materia- Fig. 6 - Lo stampo superiore, nella fase di finitura, presenta rottura dopo un numero esiguo di le in deformazione nelle parti vuote dello stampate, rispetto alla totale produzione, concentrata in una determinata zona ben visibile. Materiale stampo: X37CrMoV5 H11 bonificato 42 HRC. stampo. E’ stato quindi implementato un coefficiente alto di attrito in fase di abbozzatura (m = 0.6; µ = 0.3) stampo in fase di finitura (quello che nella realtà subiva la rote più basso in fase di abbozzatura e finitura (m = 0.1; µ= 0.05) tura dopo un esiguo numero di cicli di stampaggio). A tale scorispettando l’omogeneità di distribuzione dei lubrificanti che po si è adottato un modello dello Stampo di Finitura deformabinella realtà è ottenuta in maniera automatizzata. le, sia elasticamente che elasto-plasticamente, ed è stato calcoTutte le fasi di stampaggio (Fig.5) sono ottenute mediante la lato il grado di sollecitazione e deformazione elasto-plastica traperfetta implementazione cinematica del manovellismo della mite la proiezione su di esso delle forze ricavate dal modello a pressa meccanica precedentemente descritto. Tra una fase di stampi rigidi. Dall’analisi delle sollecitazioni dello stampo dustampaggio e quella successiva è stato implementato il calcorante la fase di finitura si evidenzia, nella parte finale di deforlo della caduta termica in aria per un tempo necessario alla mazione, la concentrazione di elevati valori della tensione prinmovimentazione reale della billetta, ottenendo quindi una cipale (1srPrincipalStressTensor) in quella che nella realtà appamappa della temperatura più adiacente alle condizioni reali di re come la linea di innesco della frattura (Fig.6); se positivo, il stampaggio. 1srPrincipalStressTensor rappresenta il massimo sforzo di trazione, ed il superamento di valori critici è il primo fattore di rottuTutte le fasi di stampaggio (Fig.5) sono ottenute mediante la ra fragile. I valori pur non superando quelli critici hanno caratperfetta implementazione cinematica del manovellismo della tere ciclico, per cui la fenomenologia da indagare è quella di rotpressa meccanica precedentemente descritto. Tra una fase di tura per fatica oligociclica. stampaggio e quella successiva è stato implementato il calcoLo stampo superiore, nella fase di finitura, presenta rottura dolo della caduta termica in aria per un tempo necessario alla po un numero esiguo di stampate, rispetto alla totale produziomovimentazione reale della billetta, ottenendo quindi una ne, concentrata in una determinata zona ben visibile. Il materiamappa della temperatura più adiacente alle condizioni reali di le stampo è X37CrMoV5 H11 bonificato 42 HRC. stampaggio. I risultati ottenuti dal calcolo FEM, sono stati confrontati con quelli reali di stampaggio validando la scelta dei nuFenomeno di Rottura per Fatica Oligociclica merosi parametri di processo assunti nelle varie fasi. La forma fiLo studio condotto ha permesso di legare la fatica ai fenomeni nale dello stampato, la sua mappa termica e le forze di stampagdi micro-deformazioni plastiche cicliche locali indotte dal ciclo gio calcolate sono identiche a quelle ottenute nella realtà, così di sollecitazioni, il cui valore di sforzo localmente può superare come i difetti di ripieghe sono collocati negli stessi punti, cioè il carico di snervamento anche se il carico macroscopico esterno in bava e nelle zone di lavorazione meccanica successiva. rimane sempre al di sotto di esso. Il danneggiamento per fatica Tale studio preliminare condotto ha avuto l’obiettivo di modelprocede attraverso un primo assestamento microstrutturale, che lare le condizioni reali di processo, fino a poter valutare il grastabilizza il ciclo di isteresi plastica dello stampo metallico e, di do di sollecitazione degli stampi durante il processo deformaticonseguenza, stabilizza alcune caratteristiche meccaniche e fisivo. Gli stampi, come precedentemente affermato, sono stati asche dello stesso. Si generano microintagli dovuti a slittamenti sunti come infinitamente rigidi ed indeformabili, per cui la se"disordinati" dei piani cristallini del metallo che nella successiconda fase di studio, partendo dai risultati validati, ha valutato, va fase di nucleazione andranno a costituire l'innesco del dancon approccio disaccoppiato, lo stato di sollecitazione dello neggiamento per fatica. Gli sforzi risultano amplificati per effetto d'intaglio cosicché facilmente il materiale in quel punto cede e si formano delle microcricche. Queste tendono a riunirsi andando a formare la cricca vera e propria, che si considera ormai nucleata quando raggiunge la profondità di circa 0,1 mm. Dopo la nucleazione della cricca, la sua propagazione avviene in maniera fragile e in senso perpendicolare a quello del massimo sforzo. L'avanzare della cricca porta ad una progressiva diminuzione di sezione resistente: quando questa diventa inferiore alla Fig. 5 - Risultati delle simulazioni di stampaggio
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sezione critica, si ha la frattura finale di schianto per sovraccarico (statico). La resistenza a fatica degli stampi è frutto della combinazione di stress meccanici e termici, in Fig.7 è rappresentata qualitativamente la metodologia di Valutazione composita delle componenti meccaniche e termiche della deformazione, ciò ha permesso di stimare la vita utile dello stampo studiandone la sollecitazione ed i suoi effetti di fatica (Materiale stampo: X37CrMoV5 H11 bonificato 42 HRC). Al fine di valutare eventuali variazioni termiche sullo stampo, sono state analizzate le temperature della billetta in corrispondenza della zona maggiormente sollecitata ed i fattori metallur- Fig. 7 - Valutazione composita delle componenti meccaniche e termiche della deformazione gici di influenza Il limite di fatica si lega inevitabilmente: Con algoritmi di tipo MAES (Meta-model Assisted Evolution • alla tensione di rottura Rm ed ai fattori che la modificano; Strategies MAES) si utilizza una valutazione delle minimizzazio• fattori meccanici legati all'esercizio e al dimensionamento ni e dei vincoli per selezionare gli individui che si vogliono efdel prodotto metallico; fettivamente calcolare. Ci sono differenti tecniche per costruir• la finitura superficiale e la corrosione. lo e il tempo di valutazione usando il Meta Model varia in funzione della tecnica scelta ma in tutti i casi esso è molto più breAnche la forma del pezzo ha importanza sulla vita a fatica, ogni ve della semplice analisi FEM ed è quindi possibile incrementalieve variazione di sezione, determinando delle concentrazioni di re la dimensione della popolazione mantenendo il tempo per tensioni e localizzando le deformazioni, agisce sempre nel senl’ottimizzazione pressoché costante. so di una netta diminuzione del limite di fatica, per questo hanno un'azione dannosa fori, intagli e spigoli vivi. Ottimizzazione di Processo Lo studio di lavorazione per deformazione fin qui descritto è stato propedeutico alla ricerca del miglior setup per l’individuazione dell’ottimo binomio prodotto/processo ed all’analisi avanzata dell’influenza dei vari parametri. Si è proposto quindi l’impiego di un approccio statistico da correlare alla fase di raccolta dati che permettesse alla progettazione di raggiungere i seguenti risultati: • riduzione dei tempi di sviluppo dei processi; • uso più efficiente delle risorse; • maggiore affidabilità dei processi. Nell'ambiente industriale la complessità dei fenomeni impedisce il pieno controllo dei fattori sotto indagine e una conoscenza teorica completa: ciò significa che non sempre è nota a priori la relazione di causa-effetto tra i fattori che influiscono sul processo in esame e le variabili da ottimizzare, una delle tecniche di progettazione per massimizzare le informazioni derivanti da dati sperimentali è il Design of Experiments (DOE), metodo che consta di due fasi principali: • fase di screening: identificazione dei fattori significativi e loro correlazione; • fase di ottimizzazione: identificazione della risposta. La scelta dell’algoritmo nel codice numerico utilizzato è di tipo generico: • iniziare da una popolazione: un numero predefinito di individui che può essere definito prima generazione; • valutarli (calcolarli e valutare minimizzazioni e vincoli); • selezionare i migliori, riprodurli e creare una nuova generazione.
Fig. 8 - Scelta casuale della popolazione iniziale rispetto al numero dei parametri
Tali algoritmi presentano la limitazione di richiedere diverse centinaia di valutazioni e di simulazioni complete; la Strategia di Evoluzione Assistita da Meta-Model (MAES) rende possibile ridurre considerevolmente il numero dei calcoli effettivi. Si possono ottenere buoni risultati all’interno di poche decine di calcoli e grazie al calcolo parallelo, le analisi/simulazioni possono essere condotte allo stesso tempo riducendo il tempo di ottimizzazione. Gli algoritmi evolutivi (ES) consistono tipicamente di tre operazioni: selezione, ricombinazione e mutazione, per ridurre il numero di valutazione di funzioni. Lo studio di ottimizzazione condotto sul processo deformativo preso in considerazione può essere riassunto nella scelta dei target della funzione Obiettivo da minimizzare, parametri di variazione e vincoli da rispettare: Target Obiettivo di ottimizzazione • Minimizzazione volume iniziale billetta. • Minimizzazione carico pressa durante la fase di abbozzatura. • Minimizzazione carico pressa durante la fase di finitura. Vincoli di ottimizzazione • Completo riempimento stampi in fase di finitura. • Assenza di difetti di stampaggio in fase di finitura.
Case Histories
38 - Newsletter EnginSoft Year 9 n°4 Analizzando non solo i setup efficaci, ma l’intera popolazione di parametri scelti nei ranges di interesse, si sono valutate le influenze che la variazione di parametri scelti hanno sul carico degli stampi in fase di abbozzatura e soprattutto di finitura, visto che questa è la fase in cui la rottura degli stampi avviene dopo un numero esiguo di cicli di stampaggio. Fig. 9 - Intera popolazione di individui di ottimizzazione. La variazione di massa della billetta iniziale riflette una variabilità estremamente accentuata della forza di stampaggio nella fase di abbozzatura, mentre nella fase di finitura, così come ci si aspetta dalla configurazione della fase di stampaggio, presenta una più modesta minimizzazione. Il grafico di Fig.9 riporta la totalità dei casi analizzati. Nel grafico di Fig.10 si riporta l’andamento Fig. 10 - Individui che soddisfano i vincoli della forza di stampaggio in funzione della massa iniziale di billetta, solo per i 21 casi (su 40) soddisfacenti il vincolo di completo riempimento e nessuna ripiega in finitura, si evidenzia come la ricerca dell’ottimo, pur spaziando su tutto il range, si concentra nella zona di minimo carico e minimo volume. Nel grafico di Fig.11 si riporta l’andamento della forza di stampaggio in funzione del posizionamento della billetta in fase di abbozzatura rispetto alla posizione originaria. Si nota Fig. 11 - Influenza della variazione di posizione della billetta in fase di abbozzatura sulla forza di stampaggio nella fase di abbozzatura e sulla fase di finitura. Individui che soddisfano i vincoli come la forza di stampaggio risulta essere non correlabile alla variabile posizionamento, infatti la billetta ricalcata posizionata sullo stampo inferiore di Parametri di ottimizzazione abbozzatura tende sempre a “scivolare” verso la parete di ap• Lunghezza billetta = min 94% lunghezza originale, corripoggio perdendo la variazione di posizionamento. I risultati dispondente a una riduzione massima di peso di 2 kg. mostrano come la convergenza dell’algoritmo MAES porti ad una • Posizionamento billetta: traslazione massima 15,5 mm lungo soluzione soddisfacente in cui il vincolo di riempimento è sodasse X (Xg = -2mm). disfatto dopo la prima generazione dell’algoritmo, e le generazioni successive permettono di minimizzare l’acciaio impiegato L’algoritmo MAES è stato organizzato con una popolazione di 10 e di minimizzare la forza impiegata nelle fasi di Abbozzatura in famiglie di 4 individui ciascuna, per un totale di 40 casi di commaniera significativa e di Finitura in misura minore (Fig12). In binazioni. Ogni combinazione prevede lo sviluppo di tutto il proquesta fase gli stampi accolgono tutto l’abbozzato andando a cesso di forgiatura e quindi le varie fasi di Ricalcatura, contatto con lo stesso direttamente sulla bava, il materiale in Posizionamento billetta ricalcata nella fase di Abbozzatura, deformazione è costretto a riempire, ma non può fluire verso Abbozzatura e Finitura, per un totale di 160 simulazioni complel’esterno. Le cavità degli stampi sono già completamente riemte di forgiatura. pite quando al cinematismo mancano ancora 3,5 mm di corsa, durante la quale il carico della pressa non aumenta, vista la suRisultati perficie ormai tutta in presa, bensì aumentano gli sforzi di traL’interfaccia grafica di visualizzazione dei risultati del codice zione massima sugli stampi nella sezione in cui si innesca la numerico utilizzato è estremamente intuitiva, attraverso rancricca. Tale ultimo risultato, unitamente alla deformazione e king dei diversi casi, permette di valutare immediatamente la riempimento visualizzabile step by step, ha posto le basi di imsoluzione migliore. Il ranking viene organizzato in maniera auplementazione di ottimizzazione successiva: partendo dalla sotomatica mediante una funzione di costo, che valuta il rispetto luzione migliore di prima ipotesi ed indagando un range di vadei vincoli inseriti ed il risultato ottenuto in termini di miniriazione del volume iniziale della billeta che minimizzasse ultemizzazioni richieste. Analizzando i numerevoli risultati prodotriormente il risultato ottenuto, ed aggiungendo ad essi una difti, automaticamente si riesce a distinguere, in verde, i setup che ferente geometria del preformato di Abbozzatura. hanno rispettato i vincoli di processo imposti, cioè il completo La nuova fase di abbozzatura studiata prevede un prodotto pririempimento e l’assenza di difetti nei volumi ove ciò è richievo di bava, la forma è molto meno vicina al finito di stampagsto, dalle soluzioni in arancione in cui le impostazioni non sogio, quindi più intermedia. Questa soluzione registra una noteno sufficienti a soddisfare tali vincoli.
Case Histories
Newsletter EnginSoft Year 9 n°4 -
vole diminuzione del carico pressa in fase di Abbozzatura, ma anche in fase di Finitura. La modifica al processo, dopo l’analisi di ottimizzazione e le valutazioni delle influenze dei parametri, ha permesso una distribuzione più omogenea degli sforzi e delle deformazioni nelle diverse fasi di processo, studiando una preformatura che permettesse di utilizzare ancor meno materiale (Fig.13), garantendo un completo riempimento ed assenza di difetti nel prodotto finale. Per minimizzare il rischio di rottura duttile nello stampo di finitura è stato accentuato il raggio di raccordo nel punto di innesco (R1) per non favorire la concentrazione localizzata degli sforzi di trazione, gli altri parametri geometrici (R2 ed L1) non sono significativi, così come la temperatura iniziale (T1) dello stampo perché bassa, mentre è da monitorare la temperatura finale (T2) perché ad un suo aumento corrisponde una maggiore deformabilità del materiale fino a valori critici.
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Fig. 12 - a) Diverso posizionamento in fase di Abbozzatura. b) Contatti e riempimento in Finitura del Caso Iniz. e del Caso Ott. c) Carico in Abbozzatura per il Caso Iniz. e per il Caso Ott. d) Carico in Finitura per il Caso Iniz. e per il Caso Ott.
Conclusioni Lo studio condotto sul processo di stampaggio a caldo di acciaio si è incentrato su un’analisi numerico sperimentale, i cui obiettivi principali sono stati l’ottimizzazione del processo prendendo in esame le variazioni dei parametri nei range di analisi; tale approccio ha consentito di dare rigore a quelle soluzioni nel processo in esame che discendevano dalla Fig. 13 - Influenza dei parametri geometrici dello stampo su resistenza a Fatica Termo Meccanica. semplice esperienza degli operatori ed ha con- Risparmio di materiale dopo due studi di ottimizzazione di processo. sentito l’ottimizzazione del ciclo di produzione di un componente di geometria complessa. La modellazione numerica, analizzando i fattori più influenti, ha L’ottimizzazione multi-obiettivo è stata condotta sull’intero prodato l’opportunità di proporre ulteriore minimizzazione del macesso ed i risultati hanno permesso di correlare i principali pateriale e suggerire variazioni delle geometrie degli stampi al firametri di processo ai benefici desiderati ed ottenuti: risparmio ne di avere un prodotto che in fase di finitura richieda una midi materiale (benefit economico) e diminuzione di onerosità di nore drasticità di applicazione del carico pressa, intimamente processo (benefit energetico-economico-ecologico): collegato al fenomeno di rottura degli stampi in quella • Ottimizzazione del materiale: faseL’ottima rispondenza nel confronto numerico sperimentale • -27% di risparmio di materiale scartato dopo Prima ha consentito di desumere l’affidabilità dei risultati forniti, il Ottimizzazione che potrà portare alla possibilità di migliorare cicli già esisten• -49% di risparmio di materiale scartato ti, ma anche di progettare nuovi componenti e cicli di produziodopo Seconda Ottimizzazione ne con vantaggi in termini di tempo ed economici. La sperimen• Ottimizzazione del carico pressa pari a: tazione virtuale non è più considerata come una fase di test vol• 1399 T fase di abbozzatura: - 24 % dopo Prima ta a verificare se l'implementazione pratica di un nuovo procesOttimizzazione so/prodotto risponde effettivamente agli obiettivi fissati in fa• 1200 T fase di abbozzatura: - 31,4 % dopo se di progettazione. Essa apporta valore aggiunto se pensata Seconda Ottimizzazione non solo come conferma di quanto previsto ma soprattutto co• 1500 T fase di finitura: - 4,2 % dopo Prima me potenziale fonte di opportunità di miglioramenti non intuiOttimizzazione bili a priori. • 1400 T fase di abbozzatura: - 10,4 % dopo A.Pallara - EnginSoft, Seconda Ottimizzazione Y.Cogo, S. Mazzoleni - Feat Group • Assenza di difetti e di ripieghe nella soluzione ottimizzata. Per ulteriori informazioni: • Completo riempimento in fase di finitura della soluzione Marcello Gabrielli, EnginSoft ottimizzata. info@enginsoft.it
Case Histories
40 - Newsletter EnginSoft Year 9 n°4
Nella International CAE Conference si è tenuto il Meeting Italiano degli utilizzatori di Forge Il 23 ottobre, all'interno della International CAE Conference, il centro di competenza simulazione di processo - forgiatura di Enginsoft ha voluto invitare tutti gli utilizzatori del software Forge/ColdForm per una sessione di aggiornamento sui prodotti. Transvalor, la casa produttrice del software, ha voluto essere presente con il dott. Jean Fourniols e l'ing. Laetitia Pegie, che hanno illustrato la roadmap di sviluppo dei prodotti e suggerito il "modus operandi" di utilizzo. L'incontro, al quale hanno assisitito una quarantina di persone, ha visto protagonisti anche alcuni utenti, che hanno presentato il proprio lavoro: l'ing. Sartori di Muraro-Stipaf (nella foto) ha raccontato come intere linee di laminazione circolare vengono progettate in virtuale, tenendo conto di tutte le fasi e della metallurgia del materiale, l'ing. Pallara di Enginsoft ha mostrato un caso pratico di ottimizzazione di una forcella in acciaio stampata a caldo da FEAT
Group, il dott. Michele Francesco Novella del DII - Università di Padova ha mostrato come è possibile prevedere l'evento di frattura duttile nello stampaggio a freddo ed infine l'ing Inaki Perez di Tecnalia ha illustrato come nei laboratori spagnoli si utilizzano questi strumenti per simulare il complesso processo di rotary forging. I partecipanti hanno potuto apprendere informazioni utili per l'uso quotidiano di Forge e ColdForm, ma soprattutto conoscersi e scambiarsi consigli su come far rendere al meglio questi strumenti. Il centro di competenza di Enginsoft sulla forgiatura (in foto da sinistra a destra l'ing. Andrea Pallara, l'ing. Marcello Gabrielli e l'ing. Federico Fracasso) ha nelle pause approfondito tematiche individuali, con il supporto di Transvalor. Appuntamento per tutti all'edizione numero 10 dell'Italian Forge Users' Meeting, nel 2013. Per ulteriori informazioni: Marcello Gabrielli, EnginSoft info@enginsoft.it
Events
EnginSoft al Convegno AIM di Trento Dal 7 al 9 novembre si è svolto a Trento il 34° Convegno Nazionale di A.I.M. (Associazione Italiana Metallurgia), che ha visto la partecipazione di oltre 300 persone provenienti sia dal mondo universitario e della ricerca, che dal mondo industriale. Enginsoft ha voluto essere presente a questo importante evento in una duplice veste, come sponsor e portando dei contributi scientifici nelle sessioni tecniche. E' stato quindi allestito uno stand, dove si sono alternati Marcello Gabrielli, Piero Parona e Giampietro Scarpa, che hanno dato informazioni in merito alle diverse attività di simulazione e di ottimizzazione che Enginsoft è in grado di affrontare. Per le sessioni tecniche, Marcello Gabrielli ha presentato nella sessione Acciaieria un lavoro di ottimizzazione condotto in collaborazione con FEAT Group dal titolo "Studio di fattibilità produttiva attraverso simulazione numerica", mentre Giampietro Scarpa ha illustrato nella sessione Pressocolata, che ha visto come chairman Piero Parona (Presidente del Centro di Studi Pressocolata di AIM) il lavoro "Analisi delle difettologie nel processo di pressocolata: contributo della simulazione numerica".
Enginsoft è stata invitata a tenere una lezione al Corso di "Siderurgia e fonderia" del 5° anno Corso di Laurea Magistrale in Ingegneria dei Materiali. Il 20 novembre l'ing. Marcello Gabrielli è stato invitato dal prof. Giovanni Staffelini a tenere una lezione agli studenti del 5° anno di Laurea Magistrale dell'Università di Trento - Facoltà di Ingegneria del Materali. La lezione ha riguardato una panoramica dei processi di solidificazione in lingottiera e di colata continua, affrontati dal punto di vista della simulazione numerica. Il docente ha illustrato quanto sia difficile definire un materiale per questo tipo di simulazioni, per poter ottenere dei risultati prossimi alla realtà produttiva. La presentazione di alcuni casi reali ha stimolato la discussione in aula e l'interesse dei ragazzi, che hanno visto applicate nella pratica le nozioni apprese durante il loro percorso di studi. Sono emersi anche alcuni temi di interesse, che saranno approfonditi in prossimi lavori di tesi, nei quali la simulazione potrà avere un ruolo importante.
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Multidisciplinary optimization for a IEEE 1902.1 “RuBee” tag integrated in a fiber-reinforced composite structure through the “RuBeeCOMP” Numerical Platform INTRODUCTION TO THE RUBEECOMP PROJECT THE OBJECTIVES RuBeeCOMP is a research project co-funded by the Regione Toscana (Italy) in the frame of the POR CReO funding program.
which were installed into the vehicle as illustrated in the concept picture in Figure 1, enable these measurements. The main objective of the RuBeeCOMP project is to define the best possible configuration for the composite structure and the wireless tag. For the specific work and the required data, a numerical platform was developed that coordinates both, the geometrical/functional parameters of the tag and the composite laminate. The technological platform was developed in order to integrate the data obtained during the project’s preliminary phases and from the parametric FE models, to achieve the best configuration for the executive design.
Fig. 1 - Simulation of a submarine mission for the inspection of the seabed
The aim of the project is to study, test and assess materials, systems, technologies as well as design methodologies for the manufacturing of composite material components. Wireless communication systems able to operate in radiofrequency unfriendly environments, such as oil or water, are also included in the study and project activities. At first, the composite demonstrator with the wireless communication system has been installed into a submarine vehicle, which is able to explore the seabed and to monitor the submarine environment by performing optical and sound surveys, and physical and chemical analyses. Suitable sensors
Fig. 2 - 3-point-bending test realized on composite virgin and aged specimens
Fig. 3 - Environment tests on composite specimens containing the wireless tag (a) and electromagnetic setup of the communication systems (b)
Research & Technology Transfer
42 - Newsletter EnginSoft Year 9 n°4 The five main Project “Work Packages” completed during the last two years allow to define the optimum solution for the technological demonstrator realized, guaranteeing the highest achievable level of performances in terms of structural and electromagnetic response.
Fig. 5 - Structural FE model developed in ANSYS Mechanical and ANSYS ACP environments
EXPERIMENTAL ANALYSIS Once the functional requirements of the wireless tag and the whole vehicle are defined on the base of mission length, depth and velocity expected and amount of information collected, a preliminary study of the vehicle geometry is carried out, of Fig. 6 – Draping and Flat Wrap analysis realized in ANSYS ACP on the rear double-curved surfaces the candidate wireless communication systems and of a set of candidate composite laminate, several full parametric models are realized using an materials through a rich experimental campaign. On the hybrid approach (numerical and empirical) verified within composite materials chosen, a set of physical and mechanical ANSYS Maxwell and ANSYS HFSS simulation environments. The tests are realized on virgin and aged specimens, with or main variables evaluated for the electromagnetic issue are without the wireless tag. magnetic field and inductance, functions used hereinafter in the optimization environment to select the best allowed configuration. The first model represents the prototype of an antenna with a 42mm radius multi-turn coil made of 33 loops of a copper wire (section radius equal to 0.25mm). The second model is a multi-turn printed loop on a 0.8mm thick FR4 laminate. The CPW fed antenna is made of 16 properly distanced 0.6mm wide microstrip copper line turns. The background scenario was modeled by imposing radiation boundaries to the problem region in order to simulate free emission into space. In the operational environment, the latter could be a lossy and/or conductive media like sea water Fig. 4 - Electromagnetic F models developed in ANSYS HFSS simulation or oil and it should be consequently modeled with the environment correspondent electric characteristics. To evaluate the established communication degree, two different multi-turn tags are tested: a 33-turn copper wire coil STRUCTURAL MODELS and a multi-turn microstrip coil. All the composite specimens The numerical platform developed for the RuBeeCOMP research are tested through thermal and moisture loads, structural project allows to maximize the structural and electromagnetic loads (time-increasing distributed pressure, bending), performances through suitable optimization tools, analyzing vibrations and shockproof, monitoring internal and external custom FE models built in ANSYS environment. The damages using an ultrasound waves control. The tests realized technological demonstrator’s geometry, containing the allow to make an accurate mechanical characterization of the wireless communication system, is defined during the first composite materials, analyzing the electromagnetic preliminary study on the base of the results obtained through performances of the multi-turn tags and the agreement fluid-dynamic analysis. Once the demonstrator’s geometry is between communication systems and composites as well. defined, it is imported and analyzed within the platform using the ANSYS code and in particular its ACP module - ANSYS ELECTROMAGNETIC MODELS Composite Prep/Post – which represents the most suitable tool to evaluate the whole composite structure’s performances. The The IEEE 1902.1 “RuBee” communication standard defines the ACP’s features allow to manage in an efficient and flexible way air interface for radiating transceiver radio tags using long all the pre and post-processing phases, evaluating the wavelength signals, up to 450 kHz. These devices have a very industrial feasibility according to the assumed production low power consumption (a few microwatts), they operate over process (ACP’s Draping & Flat wrap functions). Moreover, other medium ranges (0.5 to 30 meters) and at low data transfer specific features allow to verify damage conditions deriving speeds (300-9600 bps). To design and optimize the from in-plane and out-of-plane stress distributions, through communication systems dipped in a multi-layer composite
Research & Technology Transfer
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interface to build the laminate’s stacking sequence for each design during the optimization process. Through this interface the definition of the laminate layup is driven by a customized algorithm that allows to create a symmetric and balanced laminate, using practical engineering rules based on sublaminate approach, in order to guarantee an easy implementation from the production point of view. In this way the problems caused by technological effects are completely deleted, avoiding the need to insert any constraint after the definition of the composite layup within the optimization process.
Fig. 7 – Sub-laminate approach used by ESAComp-modeFRONTIER interface for the definition of the laminate’s stacking sequence for each optimization design
PLATFORM USER INTERFACE In order to create an accessible and easy-to-use technological platform and a comprehensible multidisciplinary design procedure, a Java language user interface is created through a customization focused on the logical procedure and on the specific electromagnetic and structural issues studied. When using the user interface, the designer does not need to edit the programming code manually; the code allows to manage automatically the numerical FE models, the input variables, the objective functions and the file transfers. Through the interface, the user can edit the ESAComp composite materials
customized multi-failure criteria, such as Max Stress, Max Strain, Tsai Wu, Tsai Hill, Puck 2D/3D, Hashin 2D/3D, LArC, Cuntze and so on. During the platform and user interface development, the debugging of the platform that implements the design procedure is realized using a simplified geometry in which the wireless system is contained. Once the main platform requirements are obtained in terms of effectiveness, efficiency and flexibility, its robustness and accuracy are evaluated analyzing the whole prototype structure. The technological platform allows to study the mechanical behavior of the submarine vehicle optimizing the performances, according with the objective functions related to structural stiffness and Fig. 9 – Analysis of results obtained through advanced post-processing tools in modeFRONTIER environment strength. EFFICIENT LAMINATE DEFINITION PROCEDURE One of the main results obtained during the development of the project is the processing and implementation of the ESAComp-modeFRONTIER interface within the technological platform. Within the design procedure, ESAComp fulfills the role of a library, in which the composite material data collected from the experimental campaign are contained. The material library is used by the ESAComp-modeFRONTIER
library, some geometrical and functional parameters of the wireless tag, the technological demonstrator’s geometry and the loads and constraints operating conditions. The platform allows to obtain the best solution maximizing or minimizing the objective functions linked with the structural performances considering several load cases at the same time.
Fig. 8 – User interface and modeFRONTIER workflow that manage the information and the variables of the numerical platform’s logical flow
MULTIOBJECTIVE AND MULTIDISCIPLINARY OPTIMIZATION Once all the main design parameters are defined by the interface, the numerical platform applies the implemented design procedure working independently. The information present in the material library are used to define for each design the laminate’s stacking sequence with the rules set in the ESACompmodeFRONTIER interface; the current composite laminate configuration is translated and exported for the next
Research & Technology Transfer
44 - Newsletter EnginSoft Year 9 n°4 realized, a final experimental campaign on the whole structure has been achieved to verify the quality of the electromagnetic signal within an unfriendly environment. The dissemination activities have brought a high visibility and prestige to the partial and final results obtained: the work progresses have been presented in dedicated sessions at the “International CAE Conferences” in 2009, 2010 and 2011. At this year's International Conference, the final results have been presented during the “Composite Session” where the presenters showed the technological demonstrator in a dedicated space within the ESAComp stand. Fig. 10 – Experimental tests realized on technological demonstrator in unfriendly environment
steps, represented by ANSYS HFSS (for the electromagnetic analysis) and ANSYS ACP (for the structural simulations). The numerical models built are solved and evaluated based on the strength of the objective functions’ values obtained, then available modeFRONTIER post-processing features allow to classify the results with multidimensional diagrams and charts. For the RuBeeCOMP research project, the postprocessing tools allow to evaluate the electromagnetic response of the multi-turn printed tag dipped in the fiber-
Fig. 11 – Exhibition of technological demonstrator at International CAE Conference 2012
reinforced composite laminate and the fiber-reinforced composite laminate and the structural performances of the technological demonstrator in several operating load conditions. In this case the objective functions are represented by the antenna inductance (L), magnetic field intensity (H), weight of the structure (W), displacements (D), Inverse Reserve Factor distribution (IRF). The information collected through the experimental campaign, preliminary design analyses and the results obtained through the platform, allow up to identify the best configuration to realize the executive design. CONCLUSIONS AND DISSEMINATION ACTIVITIES The RuBeeCOMP research project carried out during the last two years has enhanced the already robust relationship between EnginSoft, WASS and IDNOVA. The most important result is the production of the technological demonstrator, according to the executive design, containing the wireless communication system integrated within the composite demonstrator component. Once the demonstrator has been
Research & Technology Transfer
For more information: Fabio Rossetti, EnginSoft info@enginsoft.it
Meeting conclusivo del progetto "RuBeeCOMP" Il Competence Center fiorentino di EnginSoft ha ospitato il ‘meeting’ conclusivo del progetto "RuBeeCOMP" – attività di ricerca finanziata dalla Regione Toscana nelle modalità del programma POR CReO 2007-2013. Obiettivo principale della indagine tecnica è lo sviluppo di metodologie finalizzate alla progettazione integrata prodotto-processo per la realizzazione di componenti in materiale composito, caratterizzati da sistemi di comunicazione wireless; quest’ultimi sono concepiti al fine di operare correttamente in ambienti ostili alla radiofrequenza, come ad esempio l’acqua, l’olio, ecc. Il sistema RuBeeCOMP costituirà elemento principale di eccellenza dell’allestimento tecnologico della piattaforma AUV (Automonous Underwater Vehicle) denominata V-Fides Progetto di Ricerca al quale partecipa anche EnginSoft – e destinato alla gestione delle comunicazioni da e verso la piattaforma di lancio in acqua e/o a terra. Al sistema è infatti deputato l'onere di ricevere le informazioni dalla base, quindi la trasmissione alla stessa dei dati raccolti dal drone nel corso della missione subacquea finalizzata ad operazioni di detezione, esplorazione del fondale marino EnginSoft ha contribuito al progetto in modo poliedrico; lo sforzo tecnico spazia infatti dalla progettazione e simulazione dell’antenna di trasmissione/ricezione all’ottimizzazione del processo di produzione del supporto in materiale composito. All’incontro hanno partecipato tutti i partner che hanno collaborato allo studio e alla realizzazione del progetto: Whitehead Sistemi Subacquei (Wass), IDNova ed EnginSoft; inoltre alla riunione erano presente l’ing Vittorio Falcucci, attualmente Direttore tecnico di Eurotorp ma all’inizio dell'attività mentore e fortissimo sostenitore in Wass della liceità e delle prospettiche aspettative positive del progetto stesso e, il Professor Giuseppe Martini quale supervisore designato dalla Regione Toscana: tale ruolo, va detto, è stato interpretato in forma progressiva e stimolante, sicuramente percepibile nel corso dei meeting per la puntualità e la competenza dei chiarimenti tecnici richiesti.
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Le Novità in ambito Mechanical della nuova Release ANSYS Workbench 14.5 La nuova release 14.5 di ANSYS Workbench, uscita a Novembre 2012, presenta numerose novità utili nella quotidianità delle applicazioni ingegneristiche. In particolare, analizzando l’ambiente Mechanical, si possono individuare diverse nuove funzionalità, sia per quanto riguarda la gestione della geometria, la generazione della mesh, la definizione dei contatti, che per quanto riguarda la soluzione vera e propria del problema e il post-processamento dei risultati. Si accenna qui alle più importanti novità rinviando i lettori interessati al servizio di assistenza tecnica EnginSoft per gli approfondimenti. Per quanto riguarda la geometria, è possibile ottenere in DesignModeler, modelli di più rapida gestione sia in fase di importazione che in fase di Fig. 1 - Gestione della geometria fino a 10 trasferimento a volte più rapida Simulation (velocità fino a 10 volte superiore per modelli di grandi dimensioni!). Questo è reso possibile dal fatto che la conversione a Parasolid non avviene più al momento dell’importazione dell’intero assieme come avveniva nelle release precedenti, ma solo al momento in cui si definiscano in DesignModeler delle modifiche alla geometria, e solo limitatamente alle zone interessate da tali modifiche (fig.1) Riguardo ai contatti, una “matrice dei contatti” configurabile consente una miglior comprensione delle connessioni tra le parti. Tale matrice è completamente personalizzabile e consente di gestire sia contatti veri e propri, che connessioni generiche quali spot weld, joint e spring. E’ possibile inoltre evidenziare i contatti presenti solo su un singolo corpo o su una named selection, in modo da facilitare la comprensione delle connessioni anche per assiemi complessi (fig.2).
Fig. 2 - Matrice dei contatti
Al fine di facilitare la leggibilità di modelli complessi, sono disponibili nella nuova release sia filtri basati sul nome dei componenti o delle named selections, sia la possibilità di utilizzare colori diversi in maniera random per plottare diverse condizioni di carico, vincolo, diverse named selection così da renderle facilmente identificabili (fig.3).
Fig. 3 - Colori random per il plottaggio di named selections
Per semplificare l’imposizione di condizioni al contorno o di carico simili, quasi tutti gli oggetti inseribili in Simulation possono essere riprodotti e copiati secondo diversi pattern, mantenendo però inalterati i dettagli dell’oggetto originario. E’possibile copiare in questo modo, per esempio, l’imposizione del medesimo precarico su un insieme di viti o ripetere gli
Software Update
46 - Newsletter EnginSoft Year 9 n°4
Fig. 4 - pattern di bolt pretension
stessi controlli di mesh su corpi simili (fig.4). Eseguire sub-model consente di risparmiare tempo quando si è interessati a ciò che accade in dettaglio su una porzione del modello. Oggi in WB è completamente implementata la procedura di sub-model per modelli 3D, in via completamente nativa. La rimappatura degli spoFig. 5 - Vantaggi derivanti dall’utilizzo della stamenti nelle zone di tecnologia GPU taglio non è eseguita con comandi APDL ma attraverso procedure interne a WB, e ciò consente di utilizzare le potenzialità di rimappatura già implementate per l’importazione di carichi ottenuti da solutori esterni (coefficienti convettivi, forze, temperature di bulk,..). Per quanto riguarda la fase di soluzione, il metodo “sparse solver” adesso può utilizzare GPU multiple al fine di ridurre il tempo di soluzione (fig.5). Per ridurre le dimensioni dei file dei risultati ottenuti durante il run, inoltre, la memorizzazione di essi viene effettuata a singola precisione per quanto riguarda le grandezze derivate, come le tensioni e le deformazioni (variabili di elemento). Per lo stesso motivo, le tensioni principali non vengono salvate nel file dei risultati, ma vengono rivalutate qualora se ne richieda il plot come quantità di post-process. In questo modo si riescono ad ottenere file di risultati fino al 50% più piccoli rispetto al passato. Per modelli con geometria ciclica, al fine di minimizzare lo spazio di memoria richiesto in fase di plottaggio, i risultati possono essere mostrati ed animati su una frazione di tutto il corpo simmetrico, scegliendo il numero di settori che si vogliono visualizzare. Spesso è utile inserire carichi o vincoli particolari, che possono essere presen-
Software Update
ti in numerose analisi che si vogliono impostare, come opzione dell’ambiente di simulazione. Nuovi carichi e condizioni al contorno possono essere aggiunti ad ANSYS- Mechanical tramite il nuovo modulo di personalizzazione ACT (per esempio condizioni al contorno acustiche). E’ possibile inoltre creare risultati personalizzati, come ad esempio il plot di criteri di massimo ammissibile basati su un rapporto di tensioni vs una proprietà del materiale, e inserirli nell’albero come un qualsiasi risultato standard. E’ possibile, sempre grazie ad ACT, utilizzare WB per lanciare solutori esterni o inserire add-on esterni nell’interfaccia Mechanical. E’ spesso necessario indagare, possibilmente in modo semplice, le conseguenze di cricche che compaiono in un componente a causa del processo di manifattura o a causa della fa-
Fig. 6 - effetto della presenza di una cricca in un sub-model
tica, al fine di evitare rotture premature dello stesso. Nella nuova release 14.5 cricche ellittiche possono essere inserite in geometrie nominali importate in WB, semplicemente definendo un centro di posizionamento associato ad un sistema di riferimento e le dimensioni della cricca che si vuole rappresentare. La mesh è quindi gestita automaticamente dal software senza la necessità di ulteriori azioni da parte dell’utente. I parametri di cricca (K1 per il modo 1, K2, K3, Stress intensity factor, Mixed mode J-integral, …) possono essere postprocessati e visualizzati lungo il path che segue il fronte della cricca, al fine di agevolare la comprensione dei risultati. Una cricca può essere introdotta anche all’interno di un submodel per ridurre il tempo computazionale totale e allo stesso tempo incrementare l’ accuratezza locale dei risultati ottenuti (fig.6). Si ricorda che è sempre possibile trovare informazioni relative alle novità inserite nella release 14.5 all’interno dell’help sotto la voce “Release Notes”. Per maggiori informazioni: Valentina Peselli - EnginSoft info@enginsoft.it
Newsletter EnginSoft Year 9 n°4 -
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Simulating Gear Pairs within SIMPACK
SIMPACK, a Multi-Body Simulation software tool, enables complete mechatronic systems which include high fidelity drivetrains to be accurately simulated. The individual forces acting between the gear wheel teeth can be easily visualized with force arrows and plotted. The SIMPACK Gear Pair element enables full three dimensional behavior such as dynamically changing angular and radial misalignments to be investigated. HISTORY Fig. 1 - Bevel gear with crowning Initially developed for Formula 1 high performance engines back in 2003 (by Lutz Mauer, an used for achieving the optimum balance between solver executive board member of SIMPACK AG), the SIMPACK speed and accuracy. For example, simple one-dimensional Gear Pair functionality has since been used in a large elements may be used for torsional analyses whereas variety of industrial sectors, e.g. automotive, wind, rail, gearbox elements (e.g. planetary gear stage) may be used shipping, aerospace, concrete mills, material handling, for more detailed analyses when reaction moments on the etc. housing are required. For simulations where individual tooth contact forces are required, the SIMPACK Gear Pair GENERAL force element, FE 225, may be used. This element enables the additional analyses of the meshing forces and In SIMPACK, a large variety of elements are available for moments, shaft bending, bearing forces, and a host of the simulation of torque converters. Depending upon the task at hand, elements of various level of detail may be other pertinent analyses (Fig. 2). Gear Pair FE 225 is an analytical element, and therefore, extremely fast simulation times can be achieved. Graphical primitives are defined for the gear wheels which are subsequently used for the force calculations. This results in accurate animation of the gear tooth contacts and play. The Gear Pair FE 225 includes the following: Gear Types: • Involute spur • Helical • Ring • Rack and Pinion • Bevel
Fig. 2 - Gear box with Gear Pair forces and other resultant forces
Input: • Profile Shift • Backlash
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48 - Newsletter EnginSoft Year 9 n°4 All modification types can be input for the right and left flanks or for both together.
Fig. 3 - Motion of floating sun within a planetary stage (© IMM, TU Dresden)
GEAR PAIR FORCE ELEMENT HIGHLIGHTS For simulating gear pairs with non-parallel axes, “slicing” of the gear wheel contact area is necessary. This is achieved by setting a single parameter (i.e. “Number of slices”) within the gear pair force element. The handling of the offset angles for helical gears is now fully automatic. Slicing is also necessary if flank modification is used. Shuttling forces, i.e. the axial displacement of the contact forces, is included. In the case of helical gears, this will result in an additional tilt moment. Users can easily switch on and off, and choose between, various output value types. This enables easier handling and a more efficient use of data storage space. The different types of output are described below. GEAR PAIR DATA CHECK In order to check the input parameters and initial conditions of the gear pairs within a model, a user can perform a “Test Call”. This will result in a list being generated for each gear pair consisting of important input parameters and calculated data. Information such as the theoretical center distance, radial offset, axial offset, transverse contact ratio, overlap ratio, and total contact ratio will now be readily available.
Fig. 4 - Bevel gear primitives
• Viscous and Coulombic damping • Tooth profile and flank modification. Simulated Behavior: • Meshing frequencies • Shuttling forces • Dynamically changing misalignments (radial and angular). GEAR PAIR PRIMITIVES For all gear pair types, tooth and flank modification is available. The modifications are primarily used for smoothing the non-linear internal excitations due to the continually changing number of teeth in contact. The following modification types have been added: • Tip (Fig. 5) • Root • Circular • Left and Right Side • Lead Crowning (Fig. 6) • Input Function Array
GEAR PAIR OUTPUT VALUES By way of parameterization, a user can choose for which gear pairs the “Basic Output Values” will be generated. These values include such data as the relative angles and angular velocities, “total normal contact stiffness” and the “dynamic transmission error”. Similarly, a user can also choose which “Advanced Output Values” are to be saved (Fig. 8). These values are primarily used for analyzing the coupling forces of the gear pairs, either for the sum of all teeth in contact or the individual tooth-pair contacts. In addition the “Advanced Fig. 5 - Tip profile modification Output Values” enable easy animation of the force arrows in the PostProcessor (Fig. 9). After an integration run is complete a user can subsequently choose which output values to generate. Re-running the time integration is not necessary. Only re-performing “measurements” is required.
Fig. 6 - Crowning, left and right flank
Software Update
CONCLUSION The SIMPACK Gear Pair Force Element is an important component in the analysis of drivetrains. Full three
Newsletter EnginSoft Year 9 n°4 -
dimensional non-linear dynamic behavior can be investigated. Customer specific tooth profile and flank modification enables accurate simulation of meshing frequency excitations. Easy animation and plotting of contact forces accelerates comprehension of the dynamic non-linear behavior. Although major milestones in the development of the SIMPACK Gear Pair element have already been achieved, further development will continue to be implemented, enabling the Gear Pair to fulfill the even more demanding customer requirements of the future.
For more information: Fabiano Maggio, EnginSoft info@enginsoft.it
Fig. 7 - Rack and pinion gear
Fig. 8 - User choice for advanced output values
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TechNet Alliance Fall Meeting 2012 26th -27th October, Kassel - Germany The Fall Meeting of the TechNet Alliance, one of the world's largest networks of engineering solution providers, has taken place at the Schlosshotel Bad Wilhelmshöhe in Kassel on the last days of October. Apart from the many interesting lectures, the leading theme of the meeting was a full immersion into the HPC environment for technical computing. To update the audience from around the world on the latest developments in this area, three exciting presentations were delivered: 1. Herbert Güttler from MicroConsult provided a detailed history of HPC and a comparison chart which allowed the delegates to “travel” through the years, various versions and hardware of HPC and GPU performances in ANSYS. 2. Dejan Milojicic from Hewlett Packard spoke about his comparisons of different commercial cloud computing solutions for true HPC calculations in the engineering market. 3. Johannes Heydenreich, PhilonNet Engineering Solutions, presented his company’s experiences in setting up a remote cluster utilization at the University of Athens. Mr Güttler’s speech was an extremely deep analysis of multi GPU performances on single and multi-node clusters. It covered a very complex benchmark which was impressive in terms of its good scaling results in the thermo-elastic-plastic mechanical scenario. Already during the presentation, it became clear that it would be quite time consuming to carry on the work. Key points of the presentation where, among others, the speed performances of releases 14 and 14.5 on the new Intel platforms E5-26XX (due to compiler optimized code) and GPU/CPU scaling in both the PCG and Direct Matrix Solver. Dejan Milojicic presented a wide spectrum of benchmarks performed on commercial cloud computing services with respect to performances of multi-core scientific (chemical and number crunching) calculations. The findings were, as a professional user would expect, the following: - Commercial real HPC cloud computing can only be delivered by a limited number of providers - All web offers are only able to provide, in most cases, 4 cores and no real high speed interconnection. - True HPC for scientific computing has to be provided by specialized companies. Mr Heydenreich’s brief presentation was about the real use case of setting up a remote visualization for scientific computing at the University of Athens. He presented web components that have been chosen to deliver services to students and professors on a centralized cluster system for both calculation and visualization.
Fig. 9 - Animation arrows of normal loads “Indiv. load (fl_n) i,k”
For more information: Gino Perna, EnginSoft - info@enginsoft.it
Software Update
50 - Newsletter EnginSoft Year 9 n°4
ENGINSOFT coordinates the new “MUSIC” European Project
After a long procedure, the “MUSIC” project times, and shorter intervals between (the acronym stands for: “Multi-layer successive generations of products. control & cognitive System to drive a metal Therefore, MUSIC is strongly aimed at and plastic production line for Injected leading EU-HPDC/PIM factories, for a Components”) has finally received the cost-based competitive advantage positive approval of a technical and through the necessary transition to a scientific Committee. The decision-makers demand-driven industry with lower waste are responsible for selecting Collaborative generation, higher efficiency, robustness IP Projects in the FoF-ICT sector (Factory of and minimum energy consumptions. The Future and Information & Communication Fig. 1 - MUSIC PROJECT LOGO development and integration of a Technologies) applied to energy-aware, completely new ICT platform, based on agile manufacturing and customization. an innovative Control and Cognitive system linked to real time The core concept of the project focuses on the result of the monitoring, allows an active control of quality, avoiding analysis and the possible improvements that can be achieved defects or over cost by directly acting on the process-machine and applied to the two most representative large-scale variables optimization or equipment boundary conditions. The production-lines in the manufacturing field: High Pressure Die Intelligent Manufacturing Approach (IMA) works at machineCasting (HPDC) of light alloys and Plastic Injection Moulding mould project level to optimize the production line starting (PIM). Both are of strategic importance to the EU industry from the management of manufacturing information. An which is largely dominated by SMEs. Intelligent Sensor Network (ISN) monitors the real-time Due to the high number of process variables involved and the production acquiring the multi-layers data from different non-synchronization of the process control units, HPDC and devices and an extended meta-model correlates the input and PIM are most “defect-generating”. Moreover, “energy sensors data with the quality indexes, energy consumption consumption” processes in the EU industries provide less cost function. Data homogenization, centralization and flexibility to any changes in product and process evolution. synchronization are the key aspects of a control system to Owing to both of these factors, sustainability requires that collect information in a structured, modular and flexible machines/systems are able to efficiently and ecologically database. support the production with higher quality, faster delivery Process simulation, data management and meta-models are the key factors to generate an innovative Cognitive system to improve the manufacturing efficiency. The MUSIC project is an FP7 European project that introduces new ICT technologies at manufacturing plants with introduces significant potential impacts: (i) it can strengthen the global position of the European manufacturing industry; (ii) it can create a larger European market for advanced technologies such as electronic devices, control systems, new assistive automation and robots; (iii) it improves the intelligent management of manufacturing information for customization and environmental friendliness. The MUSIC project’s final target is the transformation of an extremely conventional manufacturing sector such as HPDC of light alloys and PIM of polymers into an Intelligent Manufacturing System, capable of zero-defect production, Fig. 2 - MUSIC core concept
Research and Technology Transfer
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Fig. 3 - MUSIC project structure in EUCOORD
energy saving and cost reduction. The achievement of this target passes through multi-level objectives, contributing to a knowledge-based and dynamic management of HPDC/PIM manufacturing data. The MUSIC Project started on September 1st, 2012 and will run for 4 years, under EnginSoft Coordination and Management, with more than 9 million Euros of costs, two thirds funded by the European Commission. MUSIC is a fully integrated project, since the Consortium is constituted by 16 complementary European members (ENGINSOFT SPA, ELECTRONICS GMBH, HOCHSCHULE AALEN, MAGMA GMBH, UNIVERSITA DEGLI STUDI DI PADOVA – DTG, FUNDACION TEKNIKER, FUNDACIO PRIVADA ASCAMM, OSKAR FRECH GMBH CO KG, TOOLCAST SNC, MAIER, S.Coop. AUDI AKTIENGESELLSCHAFT, RDS MOULDING TECHNOLOGY SPA, MOTUL SA, REGLOPLAS AG, FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V, ASSOMET SERVIZI S.R.L) which cover with their different activities and know-how, the entire value-chain, from RTD to demonstration, from prototyping to standardization, as described in the 8 work-packages into which the project is subdivided. For a more efficient and easy management of the project, EUCOORD is proving a very useful tool, since it is a web-based collaborative tool specifically designed for Project Management and Financial Accounting. It assists Coordinator and Partners in keeping the project on track, allowing project structure handling (details on Workpackages, Tasks, Milestones, Deliverables, in terms of technical content, leadership, duration and deadlines), correct data collection (partners information, profiles, contacts, detailed activities assignment with related resources), accounts management (inputs of costs and effort provided by partners are stored and validated by the coordinator), reports generation and disseminations planning, web-site creation, management and customization, including also a passwordprotected area for internal communication and document sharing, also of confidential nature. The starting point of the project was marked in Vicenza, on September 17th and 18th 2012, when the Kick-off Meeting took place. A group of 60 people representing the 16 partners engaged in the project, gathered at the University of Padova located in Vicenza, for a two-day meeting. The meeting content was articulated in three different sessions aiming respectively at:
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1. Analyzing the state of the art of the control for different devices in the production line. 2. Providing attendees with general information concerning management & coordination, communication strategies, project content and structure, partners’ interactions and contributions, responsibilities and duties in compliance with the contract and its annexes. 3. Presenting WP1 tasks and objective so to focus and structure the first RTD objectives to be discussed and performed. The activities performed by now are mainly concentrated in the technical and scientific tasks of WP1 and management (WP8) as well. First project dissemination activities have been promoted so to give visibility to project existence by presenting the public summary and objectives in two different international event, ALUMINUM 2012 (Düsseldorf Messe, 9-11 October 2012) and INTERNATIONAL CAE Conference (Lazise – Verona, 22-23 October 2012). As soon as first results and achievements will be available, further actions will be planned for targeted knowledge transfer and sharing. In this perspective the project has been submitted to NAFEMS World Congress of next year (Salzburg – June 2013). The MUSIC Project web site has been submitted to the European Commission on November
Fig. 4 - The kick-off meeting in Vicenza
15th, 2012. It describes the structure, contents and functionalities of the Project portal: http://music.eucoord.com/ and its connection with the EUCOORD platform for Project Management. This first meeting has been very successful, especially because all of the participants were enthusiastic to start the new challenge and at the same time could share with each other their cutting-edge technologies and knowledge. These exchanges among the partners are fundamental for a positive beginning of the project. The enthusiastic and promising assertiveness is essential for good and profitable results to move from “music” to “symphony” in manufacturing production lines! For more information: Nicola Gramegna, EnginSoft info@enginsoft.it
Research and Technology Transfer
52 - Newsletter EnginSoft Year 9 n°4
Modellazione e Progettazione Ottimale di Strutture Ceramiche Un progetto di ricerca e innovazione nell’ambito dei Partenariati e percorsi professionali industria-università Il gruppo di ricerca in Meccanica dei Solidi e delle Strutture del Dipartimento di Ingegneria Meccanica e Strutturale dell’Università di Trento coordina il progetto INTERCER2, finanziato dalla Comunità europea nell’ambito degli IAPP (Partenariati e percorsi professionali industria-università). Il gruppo di ricerca è guidato dai professori Davide Bigoni e Luca Deseri e include tra i suoi componenti il professor Massimiliano Gei e i ricercatori Francesco Dal Corso, Andrea Piccolroaz e Roberta Springhetti. Il progetto INTERCER2 mira ad un approfondimento della conoscenza scientifica del processo produttivo della ceramica, con il duplice scopo di ottimizzare la produzione e sviluppare nuove strategie tecnologiche ed industriali che consentano di ridurre i costi di progettazione e fabbricazione dei componenti ceramici, migliorandone contemporaneamente la prestazione e l’affidabilità. Gli obiettivi verranno raggiunti sia attraverso la modellazione della compattazione delle polveri e del processo produttivo sia mediante lo sviluppo di strutture e materiali ceramici multifunzionali avanzati.
L’industria ceramica è un settore ampiamente consolidato in Europa e le ceramiche avanzate sono cruciali nello sviluppo di nuove tecnologie, con applicazioni alla nanotecnologia; tuttavia la produzione industriale delle componenti ceramiche si basa ancora spesso su processi empirici, non sempre sufficientemente razionalizzati e difficilmente controllabili, con la conseguente generazione di quantità rilevanti di scarti e residui di produzione. Il progetto di ricerca è focalizzato sulla modellazione meccanica, implementazione numerica e simulazione dei processi produttivi, con particolare riguardo alla simulazione dei processi di formatura delle polveri ceramiche, dove il gruppo di Meccanica dei Solidi e delle Strutture ha già un’esperienza ben consolidata. Usando tecniche moderne basate sulla teoria dell’elastoplasticità si è infatti sviluppato un modello costitutivo che, tarato su prove meccaniche con protocollo preparato ad hoc, permette la simulazione di processi di formatura a freddo rendendo possibile la determinazione dello ‘spring-back’, delle distribuzioni di densità, stress residui e delle caratteristiche elastiche interne al pezzo a fine forma-
Fig. 1 - Grafici, da sinistra: distribuzioni di stress residuo, densità di vuoti e modulo di elasticità tangenziale nel componente ceramico a termine del processo di formatura. I risultati sono ottenuti da simulazioni numeriche in cui è implementato un modello costitutivo specifico per le polveri ceramiche compattate a freddo sviluppato dal gruppo di Meccanica dei Solidi e delle Strutture dell’Università di Trento.
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Newsletter EnginSoft Year 9 n°4 -
tura. Attraverso lo strumento su cui il gruppo di ricerca sta lavorando è possibile ottimizzare la forma dello stampo e la composizione delle polveri per ridurre lo scarto e ottenere pezzi di caratteristiche meccaniche ottimali. Più nel dettaglio, gli argomenti che saranno sviluppati nel progetto di ricerca sono i seguenti: Formatura di polveri ceramiche. Si svilupperanno strumenti per la modellazione e la simulazione del processo di formatura, basandosi su teorie costitutive innovative per la descrizione delle proprietà meccaniche dei materiali ceramici. Tali modelli saranno fondamentali per l’implementazione in codici numerici e la loro applicazione allo sviluppo di nuove e più efficienti tecnologie di produzione. Trattamento di composti ceramici. Una profonda comprensione dell’influenza dei parametri del materiale alla scala micrometrica all’interno del processo permetterà di raggiungere elevati standard di qualità nella produzione e sinterizzazione della ceramica. Miglioramento delle proprietà delle ceramiche. Si affronteranno problematiche legate alla meccanica della frattura ed alla caratterizzazione delle ceramiche e dei materiali compositi, impiegando in maniera duale l’approccio sperimentale e tecniche numeriche. In particolare si svilupperà una tecnica speciale per la simulazione delle proprietà ceramiche capace di descrivere i complicati processi di nucleazione del danno e di propagazione della frattura. I risultati numerici verranno verificati mediante varie tecniche a raggi x in-situ ed in laboratorio ricreando ambienti realistici. Modellazione di componenti meccaniche in presenza di difetti. Strutture ceramiche con difetti e interfacce imperfette, con enfasi sull’interazione fra incrinature e microstruttura, verranno analizzate mediante modellazione analitica e numerica. Nuove applicazioni tecnologiche per i materiali ceramici. L’obiettivo è la modellazione e progettazione di prodotti ceramici innovativi contenenti strati sottili d’interfaccia ed aventi proprietà multifunzionali. Il progetto è inoltre volto a stimolare la mobilità intersettoriale e a migliorare la condivisione delle conoscenze tra i partner del consorzio, in particolare mediante l’assunzione di ricercatori esperti, il distaccamento di personale dall’accademia al settore industriale e viceversa e l’organizzazione di conferenze internazionali, workshop e seminari. Il consorzio responsabile del progetto di ricerca, oltre all’Università di Trento, vede la partecipazione delle università britanniche di Liverpool e Aberystwyth e di due industrie. I partner industriali sono la EnginSoft, che si occupa degli aspetti computazionali della modellazione di componenti ceramiche, e la Sacmi, gruppo internazionale e leader mondiale nel settore delle macchine per la produzione di ceramici.
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Davide Bigoni e Luca Deseri Università di Trento Gruppo di ricerca in Meccanica dei Solidi e delle Strutture http://ssmg.unitn.it/ Sito del Progetto INTERCER2 http://intercer2.unitn.it/
EnginSoft ed il progetto INTERCER2 EnginSoft contribuirà al progetto collaborando con le Università e con Sacmi per lo sviluppo e l’implementazione di modelli di simulazione del processo di formatura del materiale ceramico. A partire da modelli esistenti in letteratura, che faranno da banco di prova, fino ad arrivare all’implementazione delle equazioni costitutive innovative per la descrizione delle proprietà meccaniche della ceramica che andranno declinate all’interno dello strumento FEM in relazione ai tipi di analisi richieste. Non solo, EnginSoft potrà contribuire anche alla caratterizzazione degli stessi materiali sulla base di dati sperimentali e utilizzando ove necessario tecniche DOE (Design of Experiment) per la definizione di un preciso piano di esperimenti siano essi fisici o virtuali atti a comprendere al meglio la sensibilità dei più significativi parametri di uscita rispetto a quelli di ingresso Una volta disponibili modelli rappresentativi del fenomeno sarà possibile anche implementare metodologie utilizzabili al livello industriale, ed atte alla ottimizzazione del processo di produzione delle ceramiche o parti di esso, processo che ha come fine ultimo lo sviluppo di prodotti ceramici innovativi. Il progetto pur operante sul piano della ricerca e difatto rilasciando indicazioni ingegneristiche di contenuto innovativo è già noto nelle problematiche ed in metodologia per effetto di recenti attività svolte dal team di EnginSoft Il contenuto delle attività di analisi è la realizzazione di una procedura numerica tale da consentire la determinazione della forma dello stampo di un semplice componente ceramico per ottenere una precisa geometria della ceramica a valle del processo produttivo di essicazione e cottura. Tuttavia lo studio è da intendersi come preliminare, in quanto le leggi che descrivono il comportamento del materiale in queste due fasi, sono ricavate da modelli semi-empirici noti in letteratura. Tali leggi potranno essere sostituite da modelli più accurati in eventuali fasi successive di analisi. In estrema sintesi lo studio si sviluppa sulla capacità di riprodurre una geometria in formato 3d in seguito ad una serie di analisi pilotate autonomamente ed automaticamente dal software e a partire da una popolazione di forma iniziali fino ad arrivare alla forma ottima in grado cioè di ridurre al minimo la differenza tra la forma finale ottenuta numericamente e quella obiettivo desiderio del marketing. Per ulteriori informazioni: Francesco Franchini, EnginSoft info@enginsoft.it
Research and Technology Transfer
54 - Newsletter EnginSoft Year 9 n°4
Corsi di Addestramento Software 2013 L'attività di formazione rappresenta da sempre uno dei principali obiettivi di EnginSoft. Per ciascuno dei possibili livelli cui la richiesta di formazione può porsi (quella del progettista, dello specialista o del responsabile di progettazione), EnginSoft mette a disposizione la propria esperienza per accelerare i tempi del completo apprendimento degli strumenti necessari con una gamma completa di corsi differenziati sia per livello (di base o specialistico), che per profilo professionale dei destinatari (progettisti, neofiti od analisti esperti). La finalità è sempre di tipo pratico: condurre rapidamente all'utilizzo corretto del codice, sviluppando nell'utente la capacità di gestire analisi complesse attraverso l'uso consapevole del codice di calcolo. Per questo motivo ogni corso è diviso in sessioni dedicate alla presentazione degli argomenti teorici alternate a sessioni 'hands on', in cui i partecipanti sono invitati ad utilizzare attivamente il codice di calcolo eseguendo applicazioni guidate od abbozzando, con i suggerimenti del trainer, soluzioni per i problemi di proprio interesse e discutendone impostazioni e risultati. Anche per il 2013 EnginSoft propone una serie completa di corsi che coprono le necessità di formazione all'uso dei diversi software commercializzati. Le novità proposte, confermano che l’idea che EnginSoft ha della formazione non è una realtà statica che si ripropone uguale a se stessa di anno in anno, ma è un divenire, guidato dall'esperienza accumulata negli anni, dall'evoluzione del software e dalle esigenze delle società che si affidano a noi per la formazione del proprio personale. In tale contesto EnginSoft organizza e sviluppa anche attività didattiche attraverso un programma formativo personalizzato, soluzioni di progettati in relazione alle necessità e alle specifiche esigenze aziendali del committente.
Training
In particolare, l’offerta dei corsi ANSYS viene ridefinita ogni anno per adeguarsi, sia all’evoluzione del software ed alle caratteristiche dell’ultima versione disponibile, che all’introduzione di nuovi moduli e solutori. In tale senso si segnala: • in campo fluidodinamico-strutturale l'introduzione, accanto ai corsi tradizionalmente erogati, del corso ANSYS CFX - MECHANICAL: Corso Interazione FluidoStruttura. • in campo fluidodinamico l'introduzione del corso ANSYS CFD: Corso Avanzato di Aeroacustica. Sono stati inoltre rivisti ed aggiornati i corsi relativi a tutti gli altri software sostenuti da EnginSoft per adeguarli allo stato attuale delle relative distribuzioni. In particolare per quanto riguarda SCILAB si evidenzia l’introduzione di un nuovo corso: • SCILAB-03-IT: Introduzione a Xcos e Modelica. Dal punto di vista organizzativo nel 2013 tutte le sei sedi EnginSoft saranno impegnate nella formazione, dando la possibilità agli utenti di scegliere la location a loro più conveniente in termini di vicinanza geografica alla propria società. Tutto questo a riprova dell'impegno nella formazione che, per EnginSoft, è e rimane un punto fondamentale della politica aziendale, un impegno costante verso l'eccellenza, un servizio per fare crescere i suoi clienti e, se lo desiderano, crescere con loro.
www.enginsoft.it/formazione Segreteria organizzativa: corsi@enginsoft.it
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56 - Newsletter EnginSoft Year 9 n°4
International CAE Conference: like never before! More than 700 people from all over Europe attended the 28th edition of the International CAE Conference. Special guest Professor Parviz Moin, from Stanford (USA), presented innovation algorithms aimed to simulate large scale CFDs models. The edition 2012 of the “International CAE Conference”, was held October 22nd and 23rd, at the Hotel Parchi del Garda in Lazise, Verona – Italy. More than 700 people coming from all over the world and representing the fields of research, academic and the companies operating in the sector attend the Italian landmark event in the world of simulation technology and CAE (Computer Aided Engineering). Dozens of international companies and institutions engaged in the event, hardware vendors (HP, IBM) and CAE solution’s providers: EnginSoft, ANSYS, EESTECO, Mentor Graphics, Lms , AVL, SCSK and many others. Special guest, during the morning section, was Professor Parviz Moin, founder and director of the Centre for Turbulence Research at Stanford University (California). An initiative created in 1987 as a research consortium
between NASA and Stanford University and is dedicated to the study of turbulent motions; it concerns many different areas of our daily lives: from aviation to wind energy, from medicine to biology. Professor Moin has pioneered the use of Large Eddy Simulation, which is a particular methodology for the simulation of turbulence and a reference point in the sector. The conference opened with a letter by Giorgio Squinzi, President of Italian Industrial Association – CONFINDUSTRIA - who, despite his absence, wanted to express his good wishes. Squinzi highlighted the need on the part of companies "to roll up their sleeves and tackle contingencies, without losing sight of the competitive environment in the medium term," stressing that "the issues addressed in the CAE Conference are undoubtedly exceptional competitive levers for the development of better products and reduced operational costs and times".
Fig. 1 - Prof. Parviz Moin, University of Stanford, special guest of the 2012 CAE Conference
Events
Professor Moin, in his speech, emphasized the role played by simulation in terms of business and investment as well as in occupation. "Simulation is important because it improves efficiency for companies and decreases costs he explained. Virtual testing today is used not only to validate laboratory experiments but mainly to make new discoveries, in addition, of course, to the work of designing new products. Simulations are more accurate; in particular the carrying out of the design phase has improved 20 thousand times since the origins. “Where is simulation used? As Moin explains, it
Newsletter EnginSoft Year 9 n°4 -
Fig. 2 - The Plenary Session
is an advanced technology that touches all sectors: from the design of aircraft turbines to the analysis of pollution, passing through automotive cooling systems. "Virtual simulation can become an opportunity for employment for young people: "Industry is adopting simulation in the process of design and production, so there are great opportunities for work - concluded Professor Moin. But it is essential to focus on a type of education that has a solid foundation in calculus, physics, and computer science". Among the leading companies present at the event, is EnginSoft, a world leader in innovation consulting, testing and virtual CAE, as well as being a sponsor of the conference. Stefano Odorizzi, President and Founder of EnginSoft, highlighted, in his speech, that simulation has grown over the years and he especially emphasized the large number of areas where it can be applied."Through numerical simulation it is possible to reproduce the behaviour of a particular subject in a potentially infinite number of diverse situations. From mechanics to fluid dynamics, from acoustics to the biomedical sector, simulation allows great strides forward, as it accurately reproduces reality. We have learned that networking is the key to promoting innovation, because each sector has something to offer in terms of know-how. By joining forces we can get better results". Simulation has positive repercussions in the biomedical field, as testified by Andrea Remuzzi, Director of the Department of Biomedical Engineering at the Institute of Pharmacological Research Mario Negri. Remuzzi presented the research project for "validation of computational models for surgical planning of vascular access in
57
haemodialysis patients". Currently there are about 2 million people worldwide suffering from end-stage renal disease, a condition that in most cases requires haemodialysis. As explained by Remuzzi, currently the leading cause of morbidity and hospitalization in haemodialysis patients consists of the short and long-term dysfunction in the vascular access used to connect the patient's bloodstream to the artificial kidney. "Through this project - said Eng. Remuzzi – computational tools have been developed with the specific aim of preventing complications during surgery". The next step will be to validate this study on the clinical front, in order to be able to understand the effectiveness, functionality and impact of this new tool that could pave the way for other simulation applications in the biomedical field. For more information: info@caeconference.com www.caeconference.com
Fig. 3 - Attendees at the Technical Sessions
Fig. 4 - Attendees at the Exhibition Area
Events
58 - Newsletter EnginSoft Year 9 n°4
CAE Poster Award: A reward to the genius of young researchers As part of the CAE Conference, a prize has been awarded to the top six innovative ideas in the field of simulation. Amongst the winners: The University of Padua, the Mario Negri Institute and the Polytechnic of Milan. The CAE Poster Award is an award for the genius, the commitment and the resourcefulness of young people, researchers and businesses. Among this year's winning posters are: an innovative motorcycle helmet, a project that simulates the restructuring of the Arena of Verona, a method for the treatment of heart disease, new solutions in the automotive field. This award demonstrates that simulation can be a real opportunity for young people, in their exchange of ideas with companies and institutions, to reach new frontiers in occupation and employment. The Poster Award is a project promoted and sponsored by EnginSoft, a world leader in innovation consulting, with the aim of promoting and spreading the culture of simulation and of rewarding the quality of new developments by young researchers. Six of them have been rewarded for their innovative ideas in the use of virtual simulation technology. The competition was divided into two categories: Industry (for companies) and Academy (for universities) and saw the participation of more than 50 students and businesses from all over Italy and Europe. An initial selection of the 10 best posters in each category was made by a Scientific Committee, who later announced the three winners for the Industry and three students for the Academy section, who won a Tablet PC each. The event, hosted by Luca Viscardi, of Radio NumerOne, was attended by Stefano Odorizzi, president and founder of
Events
EnginSoft, and Andrea Remuzzi, Director of the Department of Biomedical Engineering at the Institute of Pharmacological Research Mario Negri. Odorizzi said that he was pleased with the competition: "The Poster Awards were a success. Many projects were submitted, much beyond our expectations. Through this undertaking we wanted to create an opportunity for interaction between the business world and the universities." Over 50 projects were presented, 31 of which reached the final stage. They are mostly posters created by young students from Italian universities, particularly from those of Padua, Salento, Basilicata and Ferrara, from the Milan and Turin Polytechnics, from the Universities of Bologna, Cassino and Pisa. One of the projects comes from the Mario Negri Institute, while, amongst the companies, we note Mox-Off, Pierburg Pump Technology and LyondellBasell. Eng. Remuzzi, representing the Mario Negri Institute, stressed the important role that virtual simulation can have in the biomedical sector, "Biomedicine needs these new technologies to test new and different techniques, in order to achieve important results". As for the students, the winners were: • Davide Bertini, from the University of Padua; Mr Bertini submitted a poster on the simulation of renovation of complex historical buildings, such as the Arena of Verona;
Newsletter EnginSoft Year 9 n°4 -
59
• Matteo Longoni of Mox-off; Mr Longoni implemented a project to simulate the comfort of a motorcycle helmet while aiming at reducing time and costs associated with the design phase; • Marco Stevanella, from Polytechnic of Milan; Mr Stevanella presented a study to detect and quantify aortic malformations, which affect about 2 percent of the European population. Amongst the companies and the research community, the winners were: • Massimo Nutini, who submitted a poster on the characterization of plastic reinforced with glass fibre, widely used in most industrial productions. Nutini works for LyondellBasell, the third largest independent chemical company in the world; • Lorenzo Botti, from the Mario Negri Institute, presented a study, on an open source software platform, concerning a system that simulates blood circulation; • Giorgio Peroni of Pierburg Pump Technology presented a poster on the vacuum pump, for automotive applications. For more information: EnginSoft Marketing Department eventi@enginsoft.it
EnginSoft sostiene le attività di Ricerca dell'Istituto Mario Negri di Milano Venerdì 30 Novembre Stefano Odorizzi, ha visitato la sede di Milano - Bicocca dell’Istituto Mario Negri per rinnovare la collaborazione tra EnginSoft e la Fondazione iniziata in occasione dell’International CAE Conference 2012. Silvio Garattini, fondatore e Direttore dell’istituto di ricerche farmacologiche, ha accompagnato il CEO di EnginSoft in una vista ai laboratori e agli strumenti in dotazione alle centinai di ricercatori che si adoperano quotidianamente nella comprensione degli intimi meccanismi di funzionamento degli organismi viventi ed individuare le ragioni per cui insorgono le varie malattie in seguito all'introduzione di sostanze estranee. Nel corso dell’incontro Odorizzi ha consegnato al Professor Garattini un contributo di destinato ad alimentare le attività della Fondazione. “Ringrazio EnginSoft, e la sensibilità dell’ingegner Odorizzi, per l’attenzione dimostrata al lavoro svolto dell’Istituto – ha dichiarato Silvio Garattini -. Il sostegno profuso da Aziende e privati cittadini è un pilastro fondamentale e strategico sul qual poggia il Mario Negri. Questa generosità consente a tutti noi di combattere, da oltre 50 anni, la quotidiana battaglia contro le malattie dell’uomo”. “EnginSoft sostiene da sempre la Ricerca e le iniziative atte a valorizzare il capitale intellettuale dei giovani ricercatori e riteniamo questa collaborazione con il Mario Negri un ottimo modo per farlo – afferma Stefano Odorizzi -. Ringraziamo il
Professor Silvio Garattini per averci dato questa preziosa opportunità e ci auguriamo che ci siano altri importanti progetti per unire le nostre forze”. L'Istituto di Ricerche Farmacologiche Mario Negri è un'organizzazione scientifica che opera nel campo della ricerca biomedica. È stato costituito giuridicamente nel 1961 e ha iniziato le attività nella sede di Milano il 1° febbraio 1963. L’impegno della fondazione guidata da Silvio Garattini si articola, oltre che sulla Ricerca Farmacologica, anche nell’Informazione e Formazione. Infatti l'Istituto svolge anche attività di insegnamento per la formazione professionale di tecnici di laboratorio e ricercatori laureati e contribuisce, con molteplici iniziative, alla diffusione della cultura scientifica in campo biomedico: sia in senso generale che a specifico sostegno della pratica sanitaria per un uso più razionale dei farmaci. Tutti possono contribuire a sostengo delle attività dell’Istituto Mario Negri. I contributi che Enti e Privati Cittadini offrono all'Istituto di Ricerche Farmacologiche Mario Negri sotto forma di liberalità, donazioni e lasciti ereditari sono devoluti a incrementare i programmi di ricerca per lo studio delle più gravi malattie che affliggono l'uomo e a istituire borse di studio per i giovani ricercatori cui saranno affidate le ricerche future. Dettagli sulle attività di Ricerca, e come sostenerle con un contributo tangibile, possono essere consultate sul sito web dell’Istituto: www.marionegri.it
Events
CAE Poster Award 2012: Winners
Dipartimento di Costruzioni e Trasporti
Introduction The simultaneous need to preserve historic heritage and to appreciate its seismic vulnerability requires the development of techniques and methods used to properly establish the structural behaviour of historical monuments .
Method
resulting from non-destructive diagnostic tests, carried out on the masonry structures of the building, which allow to detect the real mechanical behaviour without loss of their functionality and efficiency.
Steps of the work The work has required the completion of the following basic steps:
x creation of a Finite Element Model complete in terms of structural geometry, loads, constraints and material properties;
x recovery of data from experimental studies previously carried out in significant positions of the monument;
x calibration of the model on the basis of the results of tests in situ.
Assumptions The starting hypothesis on which is based the development of the entire modeling is the use of materials with a linear elastic constitutive law . This assumption is generally recommended especially for qualitative analysis designed to asses the structural behaviour of a complex building.
Simulation and experimental validation The Finite Element Model of the whole building was refined and calibrated on the basis of data from experimental investigations carried out on the so-called "Ala" ,
t vibration modes, it was obtained a significant correspondence between simulation
what is left of external ring after destructive past earthquakes.
and experimental results which has allowed to judge the correctness of the dynamic
In 1996 were realized some tests to determine its structural behaviour in relation to
behaviour of the Finite Element Model.
dynamic stresses: the acquisition of the signals was made with four accelerometers placed in pre-selected points of the structure. The Frequency Response Function obtained represents the deformability of each point of the structure to vary the excitation frequency. Modal shapes resulting from dynamic simulation applied to the Finite Element Model
[m]
Mode 01
Mode 02
Mode 03
Frequency 1,68 Hz
Frequency 2,42 Hz
Frequency 4,91 Hz
Mode 04
Mode 05
Mode 06
Frequency 5,89 Hz
Frequency 6,20 Hz
Frequency 7,18 Hz
P03 P01
Experimental Frequency Response Function for control points P01 and P03
P04 P02
1.4E-04 1.2E-04 1.0E-04 8.0E-05 6.0E-05 4.0E-05 2.0E-05 0.0E+00 0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
11.0
12.0
13.0
14.0
[Hz]
Findings The modeling has been conducted assuming a linear elastic behaviour of all materials. This approximation has proved to be very useful to develop a model sufficiently accurate, avoiding the complications introduced by the use of non-linear diagrams. The validity of elastic modeling is demonstrated by the fact that the starting model, without corrections for adaptation to experimental values, has directly provided results very close to reality.
Future developments The study could be further developed taking into consideration the real constitutive laws of materials and the localized phenomena of deterioration which may affect the structural behaviour of the building.
CAE Poster Award 2012: Winners A multiphysic approach to improve helmets comfort and reduce time and costs in design process Longoni Matteo1, Formaggia Luca2, Ferrandi Paolo1 1
Moxoff Srl, Via D’Ovidio 3, 20131 Milano, Italy 2 MOX - Modeling and Scientific Computing Dipartimento di Matematica “F. Brioschi”, Politecnico di Milano, Italy Motivation
Goal
Improve helmet comfort in every-day conditions Key issue: pleasure of driving and safety
Develop a support design tool for engineers Simulate helmet performances efficiently
Technology
Starting point: very latest research works Handling of real and complex CAD geometries Model coupling: aerodynamics 3D, thermofluid 2D and vibroacustics 3D Multiphase (water/vapour) flows in porous media (comfort tissue/human hair) Human head sweating model for heat generation Advanced numerical methods Improvement and development of robust simulation codes Mathematical model
Vibroacoustic model - WIP!
ThermoFluid dynamic problem Navier–Stokes coupled with Darcy–Forchheimer: Penalized NS ρCF μ (ρ(u · ∇)u − μΔu) χΩf + ∇p + u + √ |u|u χΩp = 0 k k ∂T + Cf u · ∇T = ∇ · (λp ∇T ) − le s(h, w , T ) Temperature T : ∂t ∂h Humidity h: + u · ∇h = Dh Δh + s(h, T , w ) ∂t ∂w Sweat content w : = ∇ · (Dw ∇w ) − s(h, T , w ) ∂t Mv Evaporation rate s: s(h, T , w ) = E (psat (T ) − pv (h, T )) χw + 2πRT
Ωf ,p ,w = fluid , porous, wet domain ρ = air density u = flow velocity t = time μ = dynamic viscosity p = pressure k = permeability Dh = water diffusivity χ = indicator function Cf , λp , le = thermodynamics Mv , R, psat , pv = psychrometrics CF , Dw , E = coefficients
Elastodynamics equations: ⎧ ρ∂tt u − ∇ · σ(u) = f, in Ω × [0, T ] ⎪ ⎪ ⎪ ⎪ on ΓD × [0, T ] ⎪ u = 0, ⎪ ⎨ σ(u) · n = t, on ΓN × [0, T ] on ΓNR × [0, T ] ⎪ non-reflecting b.c., ⎪ ⎪ ⎪ in Ω × {0} ⎪ ∂ t u = u1 , ⎪ ⎩ in Ω × {0} u = u0 ,
u = displacement t = time n = unit normal σ = stress tensor u0,1 = initial conditions f = external force Ω = 3D domain Γ = boundaries
Discontinuous Galerkin formulation Space–Time formulation Multi-domain formulation 3D hexa mesh
Multiphysic approach
Results
Accurate and efficient simulations of the physics involved Evaluation tool for engineers to explore different design solutions Time and costs of the overall design process drastically improved Optimized process satisfying comfort requirements for a successful product.
References P.F.Antonietti et al., “Non-conforming high order approximations of the elastodynamics equation”, CMAME, 2012. C.Canuto and F.Cimolin, “A sweating model for the internal ventilation of a motorcycle helmet”, Computers & Fluids, 2011.
M.Longoni, L.Formaggia, P.Ferrandi Moxoff, MOX
09/2012
A multiphysic approach to improve helmets comfort
CAE Poster Award 2012: Winners ZZZ ELRPHFK SROLPL LW
Healthy and BAV-affected aortic root dynamics: Fluid-Structure Interaction simulations from MRI-based 3D models M. Stevanella1, F. Sturla1,2, C.A. Conti1, E. Votta1, A. Della Corte3, A. Redaelli1 1 Department of Bioengineering, Politecnico di Milano, Milan, Italy Division of Cardiovascular Surgery, Università degli Studi di Verona, Verona, Italy Department of Cardiothoracic and Respiratory Sciences, Seconda Università di Napoli, Naples, Italy 2
3
Results and Discussion
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CAE Conference 2012
CAE Poster Award 2012: Winners D i Design & CAE C Group G Europe e CAE Support to the Design n of Parts made of GF GF-PP PP* PP ((*Glass Fiber- Reinfo orced Polypropylene) yp py )
M.Nutini M Nutini1, M.Vitali M Vitali1, M.C.Ferrari M C Ferrari1, C.Garc C Garc cia2, D.Sinnone D Sinnone1, F.Secchiero F Secchiero1, F.Weber F Weber3 1 Basell
Poliolefine italia srl; 2 Basell Poliolefinas Co. Co EspaĂąola a S L; 2 Basell Polyolefine Gmbh; Companies of LyondellBasell a,S.L;
Abstract
Simplified method based on orthotropic material laws
Glass fiber Gl fib reinforced i f d polypropylene l l (GF PP) materials (GF-PP) t i l are replacing l i metal t l and d engineering i i polymers l i automotive in t ti structural t t l applications Like all glass fiber reinforced thermoplastics, applications. thermoplastics GF-PP GF PP products can show anisotropy caused by fiber orientation induced by the injection process. process Taking into account fiber orientation in the simulations allows the designers to improve the accuracy of the analyses y and can avoid some arbitraryy choices needed when using g an isotropic p material law. Two methods are here presented: A first approach is based on micromechanical modeling through homogenization methods available from commercial software (Di i tÂŽ) This (DigimatÂŽ). Thi allows ll coupling li off the th structural t t l analysis l i with ith the th fiber fib orientation, i t ti which hi h is i obtained bt i d from f th numerical the i l simulation of the injection process. process The authors developed a simplified approach where the presence of the reinforcing glass fibers is kept into account using an orthotropic p material law. Here the reference directions are g given byy the material flow direction, which can be obtained from a moldfilling analysis. Both the approaches request very simple tensile tests for the determination of the model parameters. I the In th design d i phase, h th choice the h i off either ith approach h will ill depend d d on the th problem bl t be to b studied, t di d on the th resources and d timing ti i available, il bl and on the desired accuracy. accuracy
A simplified method based on an orthotropic non-linear material law with an already existing Ls-dyna (MAT_103) has been d developed. l d F Fundamental d t l items it off thi this approach h are:
Selection of an anisotropic material law ((LS-DYNA (LS DYNA MAT MAT_103) 103)) The selected law (Ls-dyna (Ls dyna MAT_103) MAT 103) is isotropic elastic - anisotropic viscoelastic; its parameters are identified through the simulation of the tensile test on two different orientations using g MOGA ((Multi-Objective-Genetic-Algorithm) j g ) based optimization. p By so doing, a Pareto diagram is built onto which the best set of parameters is identified. As for the approach based on micromechanics, using specimens cut from injection molded plaques is of paramount importance to h have th desired the d i d orientation i t ti with ith respectt to t the th flflow and d similar i il to t the th one obtained bt i d in i the th reall parts. t
Moldfilling analysis results (flow directions) transferred into the structural mesh
Material Structure IIn a multi-phase lti h material t i l such h as SGF-PP, SGF PP th the mechanical h i l properties ti depend d d on the th constitutive tit ti properties ti off the th base b materials t i l and d the composite morphology, morphology ii.e., e the weight fraction fraction, length, length diameter and orientation of the fibers fibers. These properties are induced by material processing, processing as in the case of injection molding molding. Here Here, a classical skin-core skin core structure is observed and and, depending on the thickness,, can be more or less pronounced. p Along g the material thickness,, a central p portion,, or â&#x20AC;&#x153;coreâ&#x20AC;?,, is characterized byy fiber orientations perpendicular to the flow, and a lateral portion is characterized by fiber orientations parallel to the flow.
Moldflow predicted flow direction as material orientation Flow direction from a simple filling analysis is transferred to FEA model as material orientation to be used as reference system for an orthotropic material law.
Failure criteria â&#x20AC;˘ A critical step which is common to both the approaches is the definition of appropriate failure criteria. Best results are achieved when failure criteria are implemented with the characteristics as: A i l tstepi which Anisotropic (Orientation (O ti dependent) d to dboth A- critical h hi ist common b ht) approaches h is the h d definition f off appropriate failure f l criteria. Strain dependent Best resultsrate are achieved when failure criteria are implemented with characteristics such as: Sensitive to(Orientation differentiation tension/ compression -- Anisotropic dependent) Strain rate dependent Sensitive to differentiation tension/ compression
CT image g of GF-PP sample Source: test performed for LyondellBasell by Fraunhofer ITWM
Validation Several benchmark tests were carried out to validate both the approaches proposed proposed.
Method based on Micromechanical Modeling g Two-scale models are used with a macro-scale associated to the part p and a micro-scale associated to the material microstructure. The transition between the two scales can be accomplished through a homogenization process. In this case, fiber content, geometry and fiber distribution, together with the matrix properties, are the required parameters.
â&#x20AC;˘ A first drop test on an injection molded GF-PP box was used to compare the computed force vs. displacement with the experimental curve. The anisotropic simulation using the simplified method was compared with the isotropic analyses, showing a d fi it l b definitely better tt accuracy ((shown h b below). l )
Fundamental items of this approach are then:
Prediction P di ti off Fib Fiber orientation, i t ti , transferred t f d to t the th structural t t l mesh Dedicated software as DigimatÂŽ DigimatÂŽ-MAP MAP by e e-Xstream Xstream are used to map the fiber orientation, orientation predicted by moldfilling analysis onto a p TRI mesh,, into a shell â&#x20AC;&#x201C; QUAD mesh (Fig. ( g a below)) Mid-plane The fiber orientation is predicted using a transport equation for the orientation tensor components aij . Appropriate parameters â&#x20AC;&#x201C; as th fib the fiber interaction i t ti coefficient ffi i t Ci - mustt b be determined. d t i d Thi This is i a critical iti l point: i t a validation lid ti phase h is i mandatory d t for f reliable li bl predictions Here a comparison with measurement from X-ray predictions. X ray tomography is shown (Fig. (Fig b, b below)
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â&#x20AC;˘ A second d drop d test t t on th the same box b but b t with ith an impactor i t off larger l dimensions di i was used d to t compare the th fracture f t patterns. tt Th The results using the simplified method results, method, show a good agreement with the experimental pattern under a great variety of testing conditions and materials. materials Shown below is an example reported with a GF GF-PP PP having a soft matrix matrix.
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â&#x20AC;˘ An impact test on an industrial part as a ribbed beam is proposed for a deeper investigation of the rupture pattern using a different failure criteria. The results, using a Tsai-Wu model coupled with Ls-dyna MAT_103, show a very accurate reproduction of the failure pattern.
Fig. a: Orientation tensor mapped from the TRI mesh used in moldfilling analysis to the QUAD mesh used in structural calculations
Fig. b: Comparison between orientation tensor values predicted and measured on a GF-PP GF PP sample
Fig. c: Comparison between Fig measured and simulated tensile stress-strain curves on specimens cut from a plaque along different orientations
Material laws based on Homogenization method Mean field homogenization software â&#x20AC;&#x201C; like DigimatÂŽ â&#x20AC;&#x201C; are used to predict the non linear constitutive behavior of a multi-phase material, t i l combining bi i the th characteristics h t i ti off each h single i l phase h iinto t an h homogenized i d law l for f the th composite. it
Parameter identification f through optimization Reverse Engineering g g is used byy simulating g the tensile test on specimens pec cut from injection ject molded p plaques aques along g to different orientations with respect to the flow to identify the material law parameters (Fig. c above).
Courtesy from Faurecia Seatings
Conclusions Co c us o s â&#x20AC;˘ Anisotropic materials as GF-PP can be properly modeled using an orthotropic material law, as Ls-Dyna MAT_103, or more e complex approaches as those based on micromechaiical modeling. â&#x20AC;˘ In both cases, cases the information from the injection process is critical for the accuracy of the solution and needs to be carefullyy evaluated and transferred to the structural analysis analysis. â&#x20AC;˘ The Th results lt are d definitely fi it l more accurate t th than simply i l using i iisotropic t i methods. th d
References [1] M.Nutini, M.Vitali, â&#x20AC;&#x153;Simulating anisotropy with Ls-dyna in glass-reinforced, polypropylene-based componentsâ&#x20AC;?, Ls-dyna Anwenderforum m, Bamberg 2010 [2] C.Ferrari, CF i C.Garcia, C G i M.Nutini, M N ti i â&#x20AC;&#x153;A â&#x20AC;&#x153;Assessmentt off Fib Fiber Orientation O i t ti i Injection-Molded in I j ti M ld d SGF-PP SGF PP itemsâ&#x20AC;&#x153;, it â&#x20AC;&#x153; C Connect! t! Moldflow M ldfl U Users Meetin M ti g 2011, 2011 Frankfurt, F kf t 2012 [3] M.Nutini, M Nutini M.Vitali, M Vitali â&#x20AC;&#x153;Simulating Simulating failure with Ls Ls-dyna dyna in glass glass-reinforced reinforced, polypropylene-based polypropylene based componentsâ&#x20AC;? components , Ls Ls-dyna dyna German Users Forum, um Ulm Ulm, 2012
CAE Poster Award 2012: Winners An Open-Source Incompressible Navier-Stokes Solver for Hemodynamic Simulations at High Reynolds Numbers 1,2Lorenzo
2Mario
Botti, 2Bogdan Ene-Iordache,
1,2Andrea
Remuzzi, 2Luca Antiga
1University of Bergamo, Dalmine (BG), Italy Negri Institute, Department of Biomedical Engineering, Ranica (BG), Italy
INTRODUCTION
RESULTS
Hemodynamic simulations rely on the ability to numerically solve the incompressible Navier-Stokes (INS) equations in realistic geometries. Physiological conditions are often associated to moderate or high Reynolds numbers flow conditions where inertial forces dominate viscous forces. Convection-dominated incompressible flows constitute a challenging class of problems both in terms of numerical stability and computational cost.
Re 400
Re 600
METHODS An INS solver implementation suitable for large scale hemodynamic simulations in complex three 3D geometries has been recently proposed in [1]. The discrete formulation is based on a pressure-correction scheme combining a discontinuous Galerkin (dG) approximation for the velocity and a standard continuous Galerkin (cG) approximation for the pressure. •The main interest of pressure-correction algorithms is the reduced computational cost compared to monolithic strategies. •The dG discretization of the decoupled momentum equation renders this method suitable for high Reynolds numbers simulations. •The cG discretization limits the computational cost associated to the Laplacian operator in the projection step. •The space couple is LBB stable for dG(k)-cG(k-1) velocity-pressure pairs as well as for dG(k)-cG(k) equal order discretizations. We propose an open-source hemodynamics solver based on this formulation [Gnuid, http://github.com/lorbot/Gnuid]. •The solver relies on libMesh [http://libmesh.sourceforge.net/] for mesh management, finite element function spaces and numerical integration. •PETSc [http://www.mcs.anl.gov/petsc/] ensures efficiency of the solution process on parallel architectures.
Steady state hemodynamic simulations in an anastomosis surgically created in the arm of an hemodialysis patient. Bottom, 253.000 elements tetrahedral mesh obtained with vmtk [www.vmtk.org]. Top row, streamlines and velocity volume rendering at Re=400 and 600. dG(2)-cG(1) discretization.
Text
Steady state hemodynamic simulations in a three-bends carotid siphon recontructed from 3D rotational angiography. Left, computational domain and hybrid mesh obtained with vmtk [www.vmtk.org]. Right, velocity contours at Re=300, 600 and 1000. dG(3)-cG(2) discretization.
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Spatial convergence of the finite element discretization evaluated on the steady counterpart of the Navier-Stokes problem proposed in [2]. We are able to confirm the theoretical convergence rates regarding to the mesh size h.
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Pulsatile simulation on a three-bends carotid siphon, Re=400, 1000 time steps per cardiac cycle. Left, maximum inflow velocity computed by means of the inverse Womersley method [5], and considering a physiological trend over the cardiac cycle. Top row, velocity contours over transversal and longitudinal sections of the siphon. 77050 elements hybrid mesh, dg(2)-cG(1) discretization.
CONCLUSIONS The ability to solve the incompressible Navier-Stokes equations by means of high order accurate finite element methods has been demonstrated. The fully implicit discontinuous Galerkin discretization of the advection-diffusion step extends the applicability of the pressure-correction algorithm to convectiondominated pulsatile flows. The decoupling of the incompressibility constraint from the momentum equation ensures an effective an robust solution process based on standard preconditioned iterative solvers.
REFERENCES 1. L. Botti, D.A. Di Pietro, J Comp Phys, submitted, preprint at http://hal.archives-ouvertes.fr/hal00458293/en. 2. C.R. Ethier, D. Steinman, Int J Num Meth Fluids, 19 (1994), 369-375. 3. S. Albensoeder, H.C. Kuhlmann, J Comp Phys, 206 (2005) 536-558. 4. S. Tsangaris, N. Stergiopulos, J Biomech, 21 (1998) 263-266. Spatial accuracy evaluated on the 3D lid-driven cavity flow at Re=1000. Top row and bottom row right, streamlines. Bottom row left, comparison with accurate results presented in [3]. 50x50x50 hexahedral mesh, dG(2)-cG(1) discretization.
The ARCH project is funded by the European Commission within the 7th framework programme (FP7-ICT-2007-2) grant agreement nr. 224390 http://www.vph-arch.eu
CAE Poster Award 2012: Winners
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66 - Newsletter EnginSoft Year 9 n°4
Le reti d’impresa? Serve un cambio di mentalità Il convegno di Veneto Innovazione con enti e aziende sul tema delle reti e delle soluzioni per finanziare l’aggregazione d’impresa. Occorre un cambio di mentalità per andare nel mercato con maggiori opportunità. Nell’epoca della crisi e della sempre maggiore competitività, la sfida della cooperazione è una della prospettive più importanti per le PMI Italiane. Tuttavia, fare rete vuol dire prima di tutto cambiare la mentalità degli imprenditori che devono superare lo schema classico della competizione per ritrovare, nel mercato, dei partner e non degli avversari con cui condividere un percorso comune di crescita e di sviluppo. È questo quanto emerge dal convegno “B2gether”, svoltosi il 22 ottobre 2012, all'Hotel Parchi del Garda, a Lazise (VR), dal titolo, “Imprese e competitività, insieme per il successo”. La tavola rotonda è stata organizzata da Veneto Innovazione, con la collaborazione del Parco Scientifico Tecnologico Kilometro Rosso, il consorzio Intellimech,
Fig. 1 - Mirano Sancin, Kilometrorosso, moderatore della Tavola Rotonda
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EnginSoft, Habitec (Distretto Tecnologico Trentino per l'energia e per l'ambiente), Distretto Aerospaziale Pugliese, Mesap (Meccatronica e sistemi avanzati di produzione) ed Ecipa, società di formazione professionale. Mirano Sancin, direttore del Parco Scientifico Tecnologico Kilometro Rosso ha aperto la conferenza parlando dell’attuale situazione italiana: “Dobbiamo guardare alla crisi come a un opportunità – ha dichiarato – perché in tempi come questi le imprese sono più disponibili a cercare nuove strade per aumentare i margini di profitto e quindi più propense verso l’innovazione”. Sancin ha proseguito parlando di “Open innovation” e di quanto la contaminazione di settori e mondi diversi sia necessaria per ripartire portando l’esperienza di Kilometro Rosso. Ma fare rete d’impresa non è però semplice. “Sembra quasi che le PMI italiane non vogliano crescere”. A dirlo è il professor Marco Vedovato, Direttore del Master in Innovazione Strategica, Università Cà Foscari di Venezia intervenuto per conto di Ecipa. “Le alleanze strategiche sono quelle che sul breve periodo danno maggiori risultati ma allo stesso tempo sono associate all’idea di un più alto tasso di
Newsletter EnginSoft Year 9 n°4 -
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triplicati”. Zangola è tornato poi sulla necessità “che al vertice ci sia uno staff di persone in grado di guidare il gruppo verso l’innovazione”.
Fig. 2 - Partecipanti alla Tavola Rotonda
fallimento”. La motivazione è legata all’innata volontà di autonomia delle piccole e medie imprese del nostro Paese, superabile solo attraverso un nuovo approccio più dirigenziale. “In Italia c’è la volontà di unirsi e di fare rete. Bisogna saper cogliere le sinergie che ma anche applicare delle tecniche a livello di management per fare in modo che le reti funzionino” conclude Vedovato. Questo tema è stato ripreso anche da Gianni Lazzari, Amministratore Delegato Habitech, Distretto Tecnologico Trentino per l'Energia e per l'Ambiente che nel corso del suo intervento ha dichiarato: “Bisogna puntare alla complementarietà ma evitando la conflittualità”. Lazzari ha proseguito parlando dell’aggregazione nel settore edile e degli strumenti per realizzarla. “L’edilizia stava vivendo una fase di stallo, era sempre più necessario rinnovare il settore. Per questo abbiamo creato le filiere”.
La conferenza si è conclusa con gli interventi di Giuseppe Acierno e Matteo Ametis. Il primo ha presentato l’esperienza del Distretto Aerospaziale Pugliese di cui è Presidente e Amministratore spiegando la necessità percepita al momento della sua fondazione di “prendere di petto l’innovazione creando un distretto che aggregasse e promuovesse le aziende del territorio”. Ametis, Vice Direttore di Veneto Innovazione ha parlato invece del ruolo della Pubblica Amministrazione sottolineando il fatto che “non deve solo erogare fondi ma aiutare le aziende a mettere le basi su cui costruire le relazioni” ma anche che è necessario cambiare i modelli mentali del management “vero ostacolo al concetto di aggregazione”. La tavola rotonda moderata dal giornalista del Sole 24 Ore, Federico Pedrocchi, è stata visibile anche in streaming web sperimentando nuove formule di divulgazione dei contenuti per l’impresa. Per maggiori informazioni: Mosè Necchio, EnginSoft info@enginsoft.it
Mauro Zangola, Responsabile di Programma Mesap ha parlato dell’aumento delle aziende che vogliono entrare nelle reti d’impresa, facendo specifico riferimento all’esperienza piemontese. “Le aziende che vogliono puntare sull’aggregazione sono aumentate gradualmente nel corso degli anni, non solo nel settore della meccatronica. Oggi in Piemonte i poli scientifici sono
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68 - Newsletter EnginSoft Year 9 n°4
CAE Conference 2012 welcomed Sponsors from Japan. Post-conference interviews based on the strong relationships between EnginSoft and its customers. Mr.Imai: The attendance was high and the conference place was excellent. We could see that both, the host and the delegates, were very positive and had high motivations. The program was well organized and included a variety of topics. We enjoyed attending different sessions and presentations on diverse and critical topics.
At this yearâ&#x20AC;&#x2122;s International CAE Conference two Japanese sponsors participated to introduce their self-developed software products which are quite unique. Akiko Kondoh, EnginSoft Consultant in Japan, had the pleasure to meet and interview the representatives of SCSK Corporation and Cybernet Systems Co.Ltd. after the event.
Interview with SCSK Akiko Kondoh: What are your main impressions of the CAE Conference 2012? Mr.Nakayama: We participated in the conference for the first time with the aim to investigate the European market for our products. I can say that we are simply impressed by the strong presence of EnginSoft in the CAE market which was clearly reflected by the large number of attendees from the EU and other, various countries. Although we were worrying about the turnout before the conference, as we had heard a lot of negative news about the economic situation in Europe, in Lazise we soon noticed that our concern proved unfounded. The quality of the conference was very high, all of the sessions including keynote speeches, user meetings, and product updates were conducted extremely well. I think that the success of the conference is
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AK: Did you have the opportunity to speak with EnginSoft? Mr.Nakayama: We appreciated the opportunity to meet with Mr. Stefano Odorizzi and other members of the EnginSoft team, to exchange opinions regarding our product. EnginSoft understands the features and advantages of the product very well. We could hear positive opinions about the effective use, from the perspective of the license sales and the consulting and engineering services for the customers. I believe that EnginSoft is a real expert organization for engineering and simulation. Mr.Imai: I feel that EnginSoft has an extensive network and strong influence on a number of different fields. Another interesting point we experienced was that EnginSoft provides CAE solutions from a much wider point of view than CAE companies in Japan. It appears to us that many of the challenges CAE engineers are facing in their work are the same or nearly the same in Italy and in Japan.
An example of a large scale mesh model (20million DOF). ADVENTURECluster
Newsletter EnginSoft Year 9 n°4 -
AK: Apart from the Conference, did you have time to explore Italy a bit? Mr.Nakayama: I went to the city of Verona by train after the conference. The old town, the scenery, the stone pavements and the river flowing through are just like I had imagined it always. I enjoyed the atmosphere in the historic city. Unfortunately, I didn’t have enough time to visit the House of Juliet which is famous, also in Japan. I hope to visit Verona and Italy again some time soon and to be able to also stay for a few days as part of a holiday. Mr. Imai: There was no time for sightseeing and to visit other places. But I enjoyed the ambience around the conference venue which was surrounded by vineyards and which allowed me to enjoy Italy. AK: Would you say that your presence at the Conference, also as an exhibitor, was effective? Mr.Nakayama: The exchange of opinions with EnginSoft and the opportunity to present our product and case stories was very valuable for us. On the other hand, it was a pity that we couldn’t talk enough with the end users directly at the exhibition booth, to understand the real feedback on our product. I guess one of the reasons was that this was the first participation in the EnginSoft Conference and our company name and our product are not yet familiar to the attendees. We think we should continue the promotional activities with patience and take time to explore and position ourselves in the European market. Lastly, I am really grateful to Ms. Luisa Cunico and Ms. Akiko Kondoh, for their deep consideration and to everybody at EnginSoft. Mr.Imai: We could understand the positive attitude towards CAE and the trend now in Europe. Both was helpful for us for defining our vision and the directions for our overseas development. Although it was not easy to obtain in-depth reactions from the attendees, due to our company being lowprofile in Europe at this time, overall it was absolutely effective for us to participate in the conference.
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glad to be able to experience the excellent atmosphere. We could exchange opinions and information very easily, with customers and other sponsors and exhibitors. AK: Did you have the opportunity to speak with EnginSoft ? Mr.Futura: I was very impressed by the EnginSoft business style. EnginSoft clearly is not just a software vendor. The company provides CAE tools to their customers, effective and substantial technologies, that are complemented with EnginSoft’s sophisticated engineering services. At Cybernet, we want to do our best to continue the good partnership with such a great company. AK: Apart from the Conference, did you have time to explore Italy a bit? Mr.Furuta: I’ve had some time to visit Milano the day before the conference. Milano’s landmark, the Duomo is a breathtaking beauty, especially due to its magnificent and sensitive design, I think. This was my second visit to Italy, and I love it. The streets and the atmosphere in Italy are always elegant and beautiful, one can feel the country’s deep culture and rich history.
Interview with Cybernet Systems AK: What are your impressions of the CAE Conference 2012? Mr.Furuta: It was a vigorous conference with so many customers from different fields, such as ANSYS users, ANSYS complementary software users, and other CAE engineers, not only from Italy but also from a wider area in Europe. I was so
PlanetsX: The Injection Molding CAE System fully embedded in ANSYS Workbench
AK: Would you say that your presence at the Conference, also as an exhibitor, was effective? Mr.Futura: Yes, it was very effective for us. Many prospects and customers visited our booth and attended our presentation. It was a great pleasure and success for us to meet a new customer who already said at the conference that he wants to use our product. We could find an opportunity for PlanetsX to go into the European market. I hope to participate in the conference again in the years ahead, to introduce promising CAE topics from Japan. This interview was conducted by Akiko Kondoh, Consultant for EnginSoft in Japan
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70 - Newsletter EnginSoft Year 9 n°4
Trainer europei di ANSYS alla scuola EnginSoft A valle dei costanti e continui confronti tra i rispettivi gruppi Si è svolto il 13 e 14 Novembre scorso, presso il Competence di sviluppatori e tecnici, per ANSYS Inc. è del tutto naturale Center EnginSoft di Firenze, il Corso di Formazione sulle chiedere a EnginSoft, in quanto profondo conoscitore della Dinamica Avanzata al quale hanno partecipato i formatori materia, di organizzare un corso avanzato sulle tematiche di ANSYS dei principali paesi europei e alcuni Channel Partner. Dinamica. La didattica di questo appuntamento si è articolata Pierre Thieffry - Product line manager di ANSYS Inc. per le su quattro filoni fondamentali: soluzioni di Meccanica Strutturale - ha affidato ad EnginSoft • la corretta lettura della fisica che governa il fenomeno l’organizzazione del corso riconoscendo di fatto al Channel dinamico da rappresentare; Partner italiano un ruolo fondamentale nello sviluppo • la capacità di leggere i dati sperimentali nei formati tecnologico dei propri prodotti e nel contempo delle risorse interpretati correttamente dal software; umane che li devono promuovere e calare nelle differenti • la metodologia numerica da impiegare per cogliere con realtà industriali. attendibilità il fenomeno dinamico in essere; La particolarità del Corso, ideato strutturalmente da Roberto • la lettura critica dei risultati, analitici e sperimentali, al Gonella – executive manager della business unit di EnginSoft per il FEM - e operativamente coordinato e condotto da fine di coglierne vantaggi e svantaggi. Al termine della due giorni fiorentina gli ‘scolari’ coinvolti Valentina Peselli - specialista tecnica sulle tematiche di non hanno risparmiato apprezzamenti positivi sia sulla dinamica avanzata - è da leggersi nella genesi dello stesso. qualità delle lezioni che il bagaglio di conoscenza espresso EnginSoft e ANSYS, infatti, interpretano all’interno del dai tutor che si sono succeduti. Mercato ruoli diversi ma complementari. ANSYS ha l’onere di sviluppare nuove capacità di calcolo, e di rappresentazione A cura della redazione della simulazione, attraverso le tecnologia agli Elementi Finiti. EnginSoft è da decenni costante applicatore delle tecnologie di simulazione e calcolo numerico quindi rivisita quotidianamente le potenzialità numeriche alla luce di casi industriali e concreti a contatto diretto con il Mercato. Per ANSYS, quindi, l’importanza strategica di un Channel Partner con le caratteristiche e l’autorevolezza di EnginSoft è duplice: infatti, da un lato essa consiste nel riportare, attraverso iniziative quali i “Council Meeting” e l’analisi tecnica delle richieste di supporto applicativo ovvero i ‘desiderata’ di ingegneri ed analisti CAE italiani utenti delle soluzioni sviluppate dall’azienda di Pittsburgh. Non meno importante il know-how espresso da EnginSoft Luxmoore e Alex Pett di ANSYS UK; Sylvain Coste e Simon Mendy di ANSYS nella conoscenza del valore dei parametri teorici che Joe Francia; Podbevsek Frans di Infinite Simulation Systems (distributore ANSYS per compongono l’uso avanzato della tecnologia al fine di l’Olanda); Czyz Tomasz di Mesco (distributore ANSYS per la Polonia); Roberto Gonella ottenere soluzioni ben rappresentative della realtà di EnginSoft; Davide Fugazza di ANSYS Belgio; Valentina Peselli di EnginSoft; Mauro Peselli, Advance Dynamic Technical Opinion Leader simulata.
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Newsletter EnginSoft Year 9 n°4 -
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