Navy & Shipbuilding Capabilities

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NAVY & SHIPBUILDING CAPABILITIES


COST-EFFECTIVE SOLUTIONS THROUGH WORLD-CLASS RESEARCH

NAVY & SHIPBUILDING CAPABILITIES


What sets us apart from conventional engineering firms? Applied science research and advanced analysis. We employ the most advanced scientific and technological tools to solve problems of national importance that concern the safety of ships, submarines, airports and military installations. We work closely with naval engineers, designers and personnel to develop cost-effective solutions to even their most vexing challenges.


Technological Creativity

MISSION & VALUES For more than 70 years, Thornton Tomasetti has stood for innovation. Mathematical modeling by our research engineers has produced new ideas, like generating bubble screens to shield vessels from mine explosions and using lightweight composites to protect loading docks against blast impacts. EPSA, NLFlex and other specialized Thornton Tomasetti-developed software have become industry and government standards. Our experience in research and development covers the broadest range of naval problems – from the response of submarines, surface ships and autonomous systems to conventional and nuclear weapons effects to noise and vibration analyses and transduction systems studies. We foster creativity and independence in our staff, cultivating employees who are passionately committed to the projects they undertake. They maintain the highest professional and ethical standards and strictly safeguard the privacy of clients and the confidentiality of their information.

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Sponsoring & Technical Oversight Agencies Office of Naval Research NAVSEA NSWC Carderock Division NAVSEA NUWC Newport Division NAVSEA 05P NAVSEA SBIR NAVSEA PEO Ships, PMS 317, PMS 400, PMS 500, PMS 515 NAVSEA PEO Submarines, PMS 397, PMS 450 NAVSEA PEO USC, PMS 406 United States Naval Research Laboratory Air Force Research Laboratory Defense Threat Reduction Agency Defense Advanced Research Projects Agency U.K. Ministry of Defence U.K. Defence Science and Technology Laboratory Department of National Defence (Canada) Federal Ministry of Defence (Germany)

© www.navy.mil

Netherlands Defence Materiel Organisation


Reducing Vulnerability

UNDEX ENGINEERING SERVICES We’ve long been at the forefront of design, analysis, testing and qualification support for U.S. and foreign navy systems for underwater explosive (UNDEX) shock. Our proprietary and thirdparty analytical approaches, and our extensive experience in the related fields of airblast and ground shock, have earned us a solid reputation for accurate engineering results. Our expertise is anchored in extensive finiteelement analysis (FEA) and computational fluid dynamics (CFD) capabilities for near- and far-field explosions. Our engineers have developed UNDEX simulation and decision-making software used extensively in the U.S. Navy and internationally. This software, as well as our analytical procedures and staff expertise, has been repeatedly validated against UNDEX test data for more than 70 years.

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© www.navy.mil

Full-ship shock testing of LPD19 Response simulation of ship structure


Judicious Use of Technology

M&S OF U.S. NAVY ASSETS Our expertise in modeling and simulation (M&S) is founded on a long history of analytical support of the U.S. Navy in physical testing and shock qualification of equipment and assets and in M&S assessments of AIREX (air explosive) and UNDEX survivability, lethality, and acoustic signatures of surface and underwater vessels. This experience enables us to consistently deliver accurate pretest predictions and to detect issues early in the concept-development cycle. We’ve also developed a host of specialty in-house software applications to resolve challenging physics or to enhance M&S quality assurance. A case in point: Our MODCHK software, developed in 1998 as an FEA model quality checker for the DDG-53 program, remains a mainstay of ship finiteelement model development at major shipyards, contractors and navy laboratories.

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Reduced-order model of frigate EPSA evaluation of turbine generator


Performance Under Pressure

SEISMIC AIRGUNS Against the backdrop of the rising cost of ship testing, the U.S. Navy recognized the need to replace traditional full-ship shock tests with a more economical and environmentally acceptable approach. Our patented airgun technology offers an alternative to conventional explosive shock testing: airguns rapidly release highly pressurized air very close to the vessel, mimicking conditions that occur when an underwater explosive detonates. This novel technology, combined with our expertise in modeling and simulation, enables us to plan and execute dockside full-ship tests with very low risk of fish kill or injury to sea mammals. In 2012, the U.S. Navy concluded that airguns should be used as the energy source for the testing element of the full-ship shock trial alternative process.

U.S. patent no. 6,662,624 and U.K. patent no. GB2355076

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Airgun array prior to deployment Pier-side airgun ship shock testing


When the Pressure Is Too Great

IMPLOSION The rapid, catastrophic inward collapse (implosion) of a submerged vessel creates shock waves in the water that are potentially damaging to nearby structures. In the design and assessment of submersible vessels, this damage potential needs to be minimized without adding significant weight to the structure. We’ve developed tools that enable the navy to rapidly assess the collapse pressure of a specified design, approximate the emanating pressure waves under hydrostatic and UNDEX conditions, and evaluate damage to nearby structures. These tools, based on high-fidelity multiphysics computational models that have been extensively validated against experimental data, help the navy manage its ever-expanding portfolio of unmanned underwater vehicle (UUV) designs.

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Implosion design assessment tool Hydrostatic implosion


Confidence in Modeling

UNCERTAINTY QUANTIFICATION Decision makers increasingly rely on computational models for component qualification, performance reliability and structural safety. But these models sometimes contain uncertainties due to data gaps, inexact model parameters and modeling approximations. The Department of Defense recognizes that deterministic solutions based on presumed information alone can produce misleading results. So the U.S. Navy contracted us to develop an uncertainty-quantification and model-validation framework for its full-ship shock-test alternative process. Our uncertainty-quantification framework, which is integrated into our software, enables us to assess the probability of possible outcomes for a model and statistically evaluates the confidence in these results.

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Probabilistic assessment of structural stability Limit state with PDF contours


Mechanics of Failure

DUCTILE FRACTURE We’ve maintained industry-leading expertise in material-failure modeling for a wide range of applications. Recently, we developed a reliable, efficient fracture-prediction methodology for large-scale structures, like ship hulls, that cannot practically be modeled with conventional approaches based on three-dimensional continua. This methodology relies on a dilatational plasticity model with a phenomenological damage function, allowing representation of the softening behavior in a shell-mechanics framework. This innovation permits the practical simulation of failure in very large ship structures. The shell-based ductile fracture-prediction approach, developed and extensively validated by our scientists, represents the state of the art in ductile-fracture mechanics for large-scale, thin-walled structures. It enables highly accurate fracture prediction while maintaining discretization levels and computational efforts that are reasonable for structural applications.

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Test (Giagmouris et al.) & simulation Thornton Tomasetti’s finite-element prediction


Multiphysical & Multidisciplinary

STRUCTURES IN FIRE We have extensive experience in simulating the thermomechanical behavior of structures exposed to fire. A notable example is our forensic investigation of the collapses of the World Trade Center towers on September 11, 2001. Our ongoing research in this field is driven by the need to assess the effects of fire on steel and aluminum ships. Under the sponsorship of the Office of Naval Research, we’ve developed a unique method that allows a unified computational approach to evaluate the operational capacity of ships during and after fires. Fire has a number of effects on metal structures, including decreased material strength and stiffness, which can lead to component failures. We have significant experience in analytically capturing these effects. At the root of this capability is a fundamental constitutive model, based on classical viscoplasticity, which allows accurate prediction of both high-strain rate deformation at low-tomedium temperatures and creep-dominated behavior at high temperatures.

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Model of aluminum ship hull section Detailed model of World Trade Center 2


Focus on Resilience

STRUCTURAL FATIGUE & AGING The need for recapitalization of aging aircraft has led to increased interest in the topics of aging and sustainment applications. This is especially important for sea-based aircraft subjected to highly corrosive environments. Changing mission profiles and the need for platform versatility also require a more general life-cycle design approach based on accurate prediction of the aging and fatigue life of complicated structures. Advanced hybrid materials, such as fiber metal laminates (FML), dramatically reduce the life-cycle costs of aircraft. We’ve developed an efficient fatigue-simulation methodology for modeling FML using a stacked-shell approach. And our multiscale framework for thermo-chemo-mechanical coupling represents the full spectrum of physics involved in aircraft fatigue evaluation. This approach can be applied to a variety of materials, including polymeric and metal matrix composites, as well as monolithic metallic components.

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Strain during delamination Model of fiber-reinforced composite


A Sound Profile

STRUCTURAL ACOUSTICS Structural acoustics is the study of the interaction between elastic waves in structures and acoustic waves in fluids. In ship systems, it affects the habitability, durability, fatigue life and acoustic signatures of platforms. We’ve been active in this discipline for decades and were among the first firms to tackle the challenging problem of the dynamic interaction of ship-sized structures with exterior fluids. Over the years, we’ve expanded our skills and simulation capabilities and applied them to a number of U.S. and foreign navy platforms. Although structural-acoustics problems are usually linear, the demand for accurate resolution at high frequencies requires very detailed computational models. Our software-development expertise, coupled with our skill in applying third-party tools, represents a unique set of capabilities for the comprehensive analysis of vibrating systems. In-house developments include advanced finiteelement analysis, analysis of structural-acoustics design problems and radiating structures, and inwater eigenanalysis of ships.

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Thornton Tomasetti

Frequency (Hz)

Frequency (Hz)

Reference

Angle (deg)

Angle (deg)

Far-field acoustics from FEM Dome for submarine chin array


Sounding Out the Obstacle

SONAR SYSTEM ANALYSIS FLEX, a commercial explicit time-domain multiphysics software package developed by Thornton Tomasetti, has played a major role in the design of sonar arrays for mine hunting, as well as underwater detection and evaluation of surface ships and submarines. Closely tying the program’s development to feedback from commercial sonar manufacturers helped ensure optimum functionality. Its superefficient use of RAM allows it to solve extremely large numerical problems, giving designers valuable insight into sonar’s theoretical capabilities. NLFlex’s intuitive GUI transducer design wizards incorporate many of the common transducer arrangements found in sonar devices. We developed these tool kits, which have been validated by suppliers, in conjunction with the U.S. Navy. NLFlex also includes a rapid 3D extrapolation and visualization tool, providing users a simple means of creating and displaying beam profiles.

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Nine-element hexagonal tonpilz array Stave projector displacement


Assessing Survivability

TEST CAPABILITIES We’ve performed heavyweight equipment and structural shock tests for the U.S. and Canadian navies, U.K. Ministry of Defence and prime contractors, using either explosives or seismic airgun technology. Combining our expert understanding of structural and equipment response to UNDEX and dynamic loading with knowledge gained through extensive trials and experimentation, we’ve developed unique UNDEX testing services and facilities. Our capabilities include full-ship shock testing and equipment and component testing using shock barges and shock machines. Our fully integrated test service offers custom test fixture design and fabrication, along with comprehensive instrumentation fitting and monitoring. For barge and small-target testing, we maintain a secure test facility at Limehillock Quarries. This is the only U.K. inland underwater testing facility licensed for meaningful test-charge sizes and having the infrastructure, test targets, access, and water depth suitable for testing naval structures and systems to U.K., U.S. and NATO standards.

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Airgun shock test of submarine Explosive test of bespoke vehicle


Better Vibration Control

PUMPKIN TM SHOCK ISOLATORS We conceived and developed these innovative naval mounts to protect against the extremes of UNDEX loading and excessive vibration for critical and sensitive equipment. Built on proven techniques used for the legacy X and Y mount family, they combine a constrained layer of elastomeric damping compound with the ability to yield under extreme loads. Key features include excellent acceleration attenuation combined with control of displacement and a high assurance that the equipment will remain captive at the most extreme levels of input. Available in a range of sizes to support masses from 10 to 3,500 pounds per mount, they’ve been proven in static testing to destruction, shocktable tests alongside competing products, and in explosive barge testing to high shock levels.

PUMPKIN TM mounts are manufactured and sold under license by Taylor Devices Inc., North Tonawanda, New York (www.taylordevices.com).

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PUMPKINTM shock isolator An ISO/CONNEX mission module on a shock barge


Physics-Informed

AI & MACHINE LEARNING We’re empowering the U.S. Navy in the acceleration of vulnerability and structural health assessments for naval platforms in a wide range of operating environments. Our physics-informed artificial intelligence (AI) and machine learning (ML) frameworks enable the development of reducedorder models that provide fast, accurate predictions. These new computational approaches make possible a new class of portable, accessible and secure software in support of the certification, decision-making and mission-planning processes. These tools effectively inherit a library of test and physics-based simulations and explore that solution space for optimal answers.

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Database Utility

Machine Learning Module

Database Update

Arrangement Unsuccessful

35% Probability

of structural damage

62% Probability of

personnel vulnerability

Arrangement Unsuccessful

35% Probability of structural damage

62% Probability of

personnel vulnerability

Fast Running Tool

Physics-informed AI / ML


HERE’S HOW

We apply scientific and engineering principles to solve the world’s challenges – starting with yours. Whether we’re focused on the design, construction and performance of buildings or expanding into new disciplines, we never limit ourselves, applying our expertise to all types of projects across a range of industries. How can we help you? We offer solutions for an ever-widening range of services and sectors.


Septem b er 2 02 1

Acoustics, Noise & Vibration Aviation Commercial Construction Engineering Critical Facilities Cultural & Community Decarbonization Defense Education Energy Façades Forensics & Investigations Government Healthcare & Research Hospitality & Gaming Insurance Life Sciences Protective Design & Security Residential Resilience Restoration & Renewal Special Structures Sports & Public Assembly Structural Design Sustainability Tall & Supertall Buildings Transportation & Infrastructure


COST-EFFECTIVE SOLUTIONS THROUGH WORLD-CLASS RESEARCH We undertake research, development and design to engineer practical solutions that manage risks to life across a diverse range of military and civilian applications. We analyze and model everything from buildings, infrastructure and industrial facilities to vehicles, biomedical devices and novel engineered materials.

Offices Worldwide

120 Broadway, New York, NY 10271 2001 K St. NW, Suite 600 North, Washington, DC 20006 2 St. David’s Drive, Dalgety Bay, Fife. KY11 9PF. UK

+1.212.367.2952 Naval@ThorntonTomasetti.com

w w w.ThorntonToma setti.com


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