U C KY L A B CA R D B OA R D S H E LT E R
S O F I E VA N B R U N S C H O T LU I S LOPEZ R UTG ER OOR PA M E L A Z H I N D O N
Ja nu a ry, 2 0 1 5 This report is the documentation of the research, design and building process for the Buckylab course 2014/2015. A brief was given to design a cardboard shelter for either a homeless person or for refugees in disaster areas. For this project, focus was given to the latter. The project consisted of research on the given material and the design brief, thus determining a set of requirements, developing from this a final design for the shelter and then building a prototype on a 1:1 scale. Primary points of importance were to use the cardboard in a structural way, to meet the needs of refugees in disaster areas and to develop a new shelter that would surpass the existing options. This report describes and visualises the process of the project. Sofie van Brunschot Luis Lopez Rutger Oor Pamela Zhindon
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TABLE OF CONTENTS
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INTRODUCTION Problem statement The goal of the project was to develop a design for a refugee shelter made out of cardboard. This objective has two main purposes: first is to try to solve the problem of emergency shelters or homes in disaster areas, where solutions should be as cheap, fast and efficient as possible. This remains a challenge and the shortcomings in this area effect refugees in disaster areas enormously. The second is to explore the possibilities of using cardboard or paper for architectural purposes. The potential of this material is well known, yet the research in this field not yet sufficient. These two problems combined provide a clear challenge and lead to the task of developing a design for a refugee shelter that can be made out of cardboard. The important questions to consider in this case are as follows. Firstly, the properties of cardboard should be determined so that the material can be used to its full potential. Secondly, the shape of the material as used in the design should be considered as to make it most economically and ecologically efficient, creating lower material cost, lower transport cost and emissions, easier handling and assembly and optimal use of available material. Furthermore, the design for the shelter should be so defined that it meets the aforementioned requirements, that is the low cost, fast transportation, fast assembly and efficiency. Next to that a human factor should be considered, which means thinking about the living quality of these shelters, the possibility of creating personal space and community building potential. The idea of using the structural properties of cardboard, as beams instead of sheets, was prominent during the very first phases of the design process. This would also add value to the design in terms of economic efficiency and a simplified transportation and assembly process. Besides that it would also give enough freedom to experiment with not only the basic requirements, but to turn the design into more humane, appealing shelter. By using cardboard for the design, new typologies and ideas for emergency shelters could be explored. To combine this with the implementation of new technologies in design and production techniques and with the possibilities of computer aided and parametrically defined design, a new sort of structure could be achieved.
Concept The final concept is a dome built from ribs interlocking in a waffle-like structure. What led to this design is the structural use of the material and the simplicity and therefor flexibility of the dome shape. The use of ribs secures flat-packaging and easy transport and it proves to also be simple and straightforward in assembly. Besides, the shape allows for a “cozy” personal space but also the use of clustering possibilities to be able to simplify the process of (re)building communities in disaster areas.
Principle The idea of the concept is based on the existing principle of a waffle rib structure, which consists of a three-dimensional grid with components (ribs) in the X- and Y-direction that intersect where they meet. At the intersection of two components in different directions, a connection is creating by means of a “half lap joint”, which cuts the top half of one of the components and the bottom half of the other component, creating a smooth joint and a continuous rib in shape and size. The principle of the waffle structure was further developed and applied through use of an algorithm built in Grasshopper. This definition was flexible, easy to adjust and could be applied to various structural shapes and objects. Several structures and buildings of different scales have been erected using this technique. Most notable precedent was the Metropol Parasol project, in Sevilla, Spain by Jürgen Mayer-Hermann.
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Finally the problem that eventually led to the initial concept and the final design was to use the structural properties of the extremely common material cardboard, aided by new techniques, to create a shelter that could be mass produced, easily and cost-efficiently transported and quickly built by anyone anywhere in the world.
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WEEK 1 22 - 24 october
S WAT a n a l y s i s The first days after the Elevator Pitch a project group was formed based on similarities or possible relations between the four different projects. To analyse the different concepts and come to a conclusion about their strengths and weaknesses, a SWAT-analysis was executed, the results of which are seen below (fig. 1 - 4).
1. Lift emergency shelter
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The idea behind the project is to develop a shelter made out of mostly cardboard that can be consistently assembled in a series of simple steps, the shelter should be able to adjust to different kinds of climate as well as providing some features out from its shape such as waterproofing, natural temperature control and better use of sunlight. The shelter is able to fit a family of 4 and its purpose is to be used in situations of natural disasters such as earthquakes, hurricanes or floods. Also economy, packing and transportation were taken into consideration in order to develop the idea.
Fi g . 1 : E l e va t o r p i t c h L u i s Lopez
WEEK 1 The project consists of three major components, a lifting honeycomb structure, a base substructure to gain height and a covering fabric. The secondary components are a base perimeter and a floor mat for the inside. The lifting structure is an hexagonal, cornered filleted of 3.1x3.1m, 20mm corrugated cardboard plate, the plate hast a series of cuts inside the shape that go around and into the center of the shape. These cuts follow the external profile and are separated an equivalent distance of 15cms one from the other. The cuts in the plate provide the shape of a honeycomb structure once it gets lifted from the center, result it a inverted cone like shape shelter strengthened by a light weight honeycomb structural pattern. Once the honeycomb is lifted, diagonal reinforcements ribs are added, each of the ribs has a connection to the columns of the substructure. Then covering fabric over proceeds, in order to start protecting the structure and gain time while putting it on to the sub-structure. It has to be known that lifting cardboard in such a way can be a bit hard since the material in such a way is strong, on the other side that characteristic helps to assure that the lifting structure plus the reinforcement ribs are enough to support the geometry. The substructure consists in a set of 6 15x15cms columns of 1.1m meters height in cardboard profile that are reinforced with scissor like pivoted structure that attach from a column to another, building a substructure around a perimeter that that to be previously set along with the floor mat, this to determine the position of the shelter. The next step will consist of setting the second part of the perimeter on top the substructure in order receives the lifting structure with the covering fabric. Once the covering fabric is taken down completely and the shelter gets fully covered and ready to use. In the scenario of package and delivery a big box could be used where panel de compiles the lifting structure will dictate the size of the packing, the same box should be able to contain all the pieces needed for the assembly of the shelter.
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+ Flat packaging/transport + Integrated covering - Not structural on its own
2. Cardboard bricks The aim of the Bucky Lab Cardboard Project was to create a cardboard shelter. There were two different approaches for its development. I chose the one, that focuses in create shelter for homeless people in the city. Some parameters for this project were established: - Since cardboard is the assigned material, structure and covering should be made of it.- Although the architectural program was not developed, it was necessary to determine the type of shelter of the design. The project aims to be the temporary place where people can stay after they are taken from the streets. Hence, this parameter would influence in the scale of the project. After analysing this aspects, I ended up with the idea of creating modular cardboard blocks, which can be assemble together and work as an whole structure. In the developing of these blocks, different volumes were tried both physically and digitally. I decided to use the structural properties of the triangle in order to provide strength to the cardboard module. So, I used the
Fi g . 2 : E l e va t o r p i t c h Pa m e l a Z h i n d o n
platonic solids: - Octahedron as the main structure: walls and roofs. - Tetrahedron as the modules that would be used to join. Â For the development of the conceptual idea of the shape, the use of Maya helped me to visualize the different options of placing and laying the bricks. In a first stage, the project consisted on only one type of module. It was a tetrahedron. At this point, Maya was not the best option for modeling the project, due to the exactitude and precision required to align the modules. Nevertheless, a script to generate a module aligned to one surface was created to facilitate the arrangement of them. Although the use of this command helped to create the geometry easily, I realized that this type of module, the tetrahedron, was too flexible to create the desired kind of shelter. Therefore, another type of module was introduced: an octahedron. This new module was settled as the main structure of the design, and the tetrahedron as the connectors between walls and roof. The use of Maya for the arrangement of the principal module was very practical. The scale of each module was around 1.5x1.5x1.5 meters. This size would allow that three
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WEEK 1 people carry the module. However for the assembly, it would be necessary the use of a crane. The design aims to be consider as a semi temporal movable urban-architectural sculpture. Nevertheless, the weak part of the project is the connection between them. This aspect was not developed due to the lack of time. + Component based + Structural components + Modular - Connections - Amount of material
3 . Wa f f l e s t r u c t u r e d o m e Since the main goal of the studio was to design a lightweight and an easy to transport paper shelter, I realized that I had to find an idea that will take advantage of the properties of the material in order to create a strong, lightweight, economic and easy transportable shelter. In this context, I started shaping my idea. The paper, as a material, it is not suitable for the outer layer of a shelter due to the fact that it is not waterproof. For that reason I knew that my shelter should be covered by another material like a waterproof textile. So I realized that I had to use the properties of paper in order to create a structure that will protect the people who are going to live there and that will give also the final shape of the shelter. As a paper material I chose the corrugated cardboard because it has a good weight – stiffness ratio, in comparison with the gray cardboard which is heavier. So I decided to design a “waffle” structure which is consists of ribs in two directions perpendicular to each other. By selecting this type of structure, we can have thin ribs and at the same time a strong structure due to the grid.
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The ribs in both directions are like rings allowing the floor of the shelter to be lifted from the ground, avoiding the moisture problem and letting the water from the rain to pass through and not gather underneath the shelter. Also because it is really important to cluster the shelter with other shelters and create bigger spaces, I designed two doors with a 90° relationship, one in each rib direction. In order to have an easy transportable shelter, each rib will be divided in 6 or 7 parts, which will have almost the same size. The division of the ribs allows all the parts to fit in small box. Each part will be tagged because the users of the shelter will have to take the pieces and assemble the ribs with specific connections. Finally the structure is covered by a prefabricated waterproof textile that it is going to be installed to the structure, from the users, as a “sweater”. In this “waffle” structure concept, the future users will take a box with the rib parts and their connections. First they will have to assemble the ribs with their connections and with tools that their also included in the box. After they have created the ribs, they will have to assemble the structure. Finally, they will have to install the prefabricated covering and then the shelter is ready for use.
+ Structural use of cardboard properties + Clustering + Shape components - Stability
Fi g . 3 : E l e va t o r p i t c h R u t g e r O o r
4. Quarter isogrid dome The main requirement for the cardboard refugee shelter was that it would provide an easy to assemble, simple structure that would provide protection from external conditions and that used the structural properties of cardboard optimally. It was also important that the shelter would need the least amount of material and the least expertise and time to assemble. Finally it should be easy to pack and transport, making it cheaper to provide the shelters. The starting point was to use the cardboard more structurally than just as flat sheets of cardboard. Therefore the cardboard was used as ribs instead of plates, with loading in the long direction, using its strength optimally. A structure for the ribs was sought and different patterns for a grid were considered. Both a rectangular and a triangular grid were considered, yet in the end a quarter isogrid was chosen. The triangular shaped grid would provide stability compared to the rectangular grid, but a quarter isogrid would do this in the same way with less material. These ribs could now be used to create any desired shape, keeping themselves in place by interlocking connections that remain perpendicular throughout the whole structure. The shape was determined by a hexagonal floor plan that forms the base of a dome. The hexagonal shape was chosen so that it would be easy to cluster multiple shelters together. This shape would give a lot more options to combine shelters and many different compositions could
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WEEK 1 be achieved this way. The hexagonal base shape also worked perfectly with the quarter isogrid. Canopies that extend from the dome were added to the design to be able to lock the domes together and create smooth connections, resulting not just in â€œhallwaysâ€? between the shelters, but melting two shelters into one area. In short, the main concept for the refugee shelter was a simple dome with hexagonal floor plan, consisting of multiple interlocking ribs that were arranged in a quarter isogrid pattern. The ribs provide optimal use of the strengths of cardboard and also make for a flat packaging system, easy to pack and transport, thus reducing CO2 emissions and costs. By using ribs, the amount of material needed for the shelter was also kept to a minimum. The simplicity of the system and the dome shape made for an easily assembled structure, perfect for emergency situations where speed and simplicity are key factors.
+ Structural use of cardboard properties + Clustering + Shape components - Stability
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WEEK 1 Rib structure After this SWAT analysis the concepts of a dome consisting of interlocking ribs in either a wafflepatterned structure or a quarter isogrid structure (see fig. 5) were deemed most structurally sound and least complex to actually build. It was decided that this concept would be further researched and developed during the project.
Fi g . 5 : Wa f f l e g r i d a n d Quarter Isogrid
Pa r a m e t e r s Looking into the geometrical properties and joining options for each building system, some parameters were needed in order to proceed with the design process. The following parameters were set:
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- Maximum internal space - Capacity to cluster multiple structures with each other - Simplicity in assembly method - Modular parts
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WEEK 2 Pa r a m e t e r s The form-finding process began to strongly rely on the previously set parameters. The parameters were defined in a more specific way and new ones were added to further specify the details of the design and help with the development. The set parameters were then as follows: - Capacity to cluster multiple structures with each other, with direct connections - Symmetry, to reduce amount of different parts and to simplify process - Simplicity in assembly method - Rib structure of a waffle grid or quarter isogrid - Floor area of inside space minimum 10 m2
Sketching and shape finding
Fi g . 6 : S k e t c h e s f o r clustering of shelters
Fi g . 8 : S k e t c h e s o f s t r u c t u ral i de a s
Fi g . 7 : S k e t c h e s o f dome shaped shelters
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To be able to proceed with the design of the cardboard shelter, possible assembly systems and shapes were explored through sketching both manually and digitally for both waffle and quarter isogrid structures. At the same time different possibilities for clustering were researched, in order to find an efficient and flexible way to create a community from the resulting shelter design.
Fi g . 9 : S k e t c h e s o f d o m e shaped shelters
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Fi g . X : S k e t c h e s o f dome shaped shelters
Fi g . 1 0 : S k e t c h i n g o f strucutre s
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Fi g . 1 1 : D i g i t a l e x p e r i m e n t i n g and sketching
Fi g . 1 2 : D i g i t a l e x p e r i m e n t i n g and sketching
WEEK 2 Rib s tructure As for the rib structure, some conclusions were already forming. The quarter isogrid appeared (in work models, see fig. X) to be extremely strong. By definition this â€œpatternâ€? would also provide more stability to the whole structure, because of the triangular shapes. However, it was found that the waffle grid would be none the less be more suitable. First of all it would need less material and less connection points, but most decisive was the fact that assembly would be infinitely less complicated.
Fi g . 1 3 : Q u a r t e r i s o g r i d wo r k m o d e l
Wo r k m o d e l A sample of the rib structure is built in a scale 1:2 working model. By taking a part of the structure and building a model of this a general idea of how the ribs will be laminated, of the main structural issues and the production technique can be acquired. It provided a way of testing certain dimensions for the structure and using these as reference for the dimensioning. Fi g . 1 4 : Wa f f l e g r i d wo r k model
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Fi g . 1 5 : Wa f f l e g r i d wo r k model
In the meantime, possibilities for covering of the structure were explored. Regardless of the final shape of the structure, the rib structure would have to be covered in some way to protect inhabitants from external conditions. The options considered were filling the holes of the structure with cardboard boxes or covering the whole dome with a waterproof cloth that would also provide insulation somehow. Below are two examples of these ideas. possible insulation cardboard boxes
Fi g . 1 6 : Po s s i b l e c ove r i n g options
waterproof fabric cover
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C ove r i n g
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WEEK 3 3 - 7 n ove m b e r
Digital de sign proce ss This week some digital experimentation began to find different shapes and forms and compare those. Using the software Rhino, Grasshopper and T-Splines, different test shapes were explored. Multiple parametric definitions were developed in Grasshopper in order to speed up the design process and make it as flexible as possible. Several definitions were tested of which some were discarded. A trial and error process began to find the final Grasshopper definition that would be able to transform various shapes in the designed grid structure. quarter isogrid
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Fi g . 1 7 : Te s t i n g d e f i n i t i o n s for s t ru c t u re s a nd sh ap e s
WEEK 3 C ove r i n g One of the proposed covering solutions was to use certain cardboard “boxes” to fill the gaps between the rib structure of the shelter. This would function as a way of closing of the interior, but also to stabilise the whole structure and to provide better connections between the ribs. However, some problems with this method are the following. It was concluded that too much material would be necessary to achieve this, that all the gaps would be varying in size too much to create a general shape for the boxes and that the boxes would soak up and retain water, dirt, etc. In the end it seemed like a too complex idea that wouldn’t necessarily add any extra qualities. Therefore it was decided to further develop the idea of a cloth covering.
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Fi g . 1 9 : I d e a f o r t h e c ove r i n g and insul ation system
WEEK 4 C ove r i n g t e s t s During this week a test was done for one of the concepts for the covering. Part of the first test model of the rib structure was covered with a cloth. To this cloth were attached “pockets” filled with insulating material, that formed a sort of cushions in between the structural ribs. Considered were easily available materials such as hay, grass, sheep’s wool, old newspapers, etc. to make the design adaptable to local products in any environment, to reuse materials and to reduce costs.
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Fi g . 2 0 : C ove r i n g t e s t
WEEK 4 Dome shaped shelter By this time a few main concepts for the shape of the shelter were left. These different shapes were researched and considered, yet the search for a appropriate form led back to the simple shape of a dome every time, as this was the most pure and simple form and the easiest to apply the rib structure to and to meet the set requirements. The digitised definition for the shape and the rib structure was therefore finalised for a dome with waffle shaped rib structure.
Pa r a m e t e r s The parameters for the shelter are now defined as follows: - Capacity to cluster multiple structure with each other, with direct connections - Symmetry, to reduce amount of different parts and to simplify process - Simplicity in assembly method - Rib structure in a waffle grid - Floor area of inside space minimum 10m2 - Dome shaped - Suitable to be defined in a Grasshopper definition - Simplicity in shape so as to be understood by user
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WEEK 4 Te s t i n g With the decision for the shape finalised, the Grasshopper definition fine-tuned and working and a first working model finished, a series of problem have to be determined and solved to improve the final design. To get a better idea of how the final shelter will work a small 1:20 scale model is made using laser-cut parts of 3mm MDF. The symmetry is also tested through this model and a first idea of the assembly process is obtained. Besides this, possible structural weaknesses that might affect or compromise the structure are examined too. Some mistakes in the definition are found and it is changed to obtain the desired symmetry. The number of ribs and the distances between each of them are also adjusted for this purpose. This leads to the final shape of a pure symmetrical ribbed dome with two sides â€œcutâ€? to provide entrances and connection possibilities. A second scale 1:20 model is laser-cut from 3mm MDF and confirms the final shape.
Fi g . 2 2 : Te s t m o d e l 1 : 2 0
Fi g . 2 3 : I n t e r i o r v i e w o f both 1:20 models clustered
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Fi g . 2 4 : A s s e m b l y o f t h e test model 1:20
WEEK 4 Connections However, it is found that by using the continuing ribs that form â€œringsâ€?, even if this is only in one direction, the design is compromised extremely. Not only does this strongly complicate the assembly process, it is also highly likely that the corners will weaken the entire structure. The rings are therefore discarded. Instead, ribs for the floor and ribs for the dome are now considered separately and connections between these elements need to be designed.
? Fi g . 2 5 : D i s c a r d i n g r i n g s t r u c t u r e , connection solution needed
Meanwhile, laminating tests begin in order to understand the capability and technique on how to join the ribs for the dome, since they individually surpass the size of the module given by the cardboard supplier. Different techniques are tried but it is concluded that easiest would be to glue a number of layers together by means of overlapping parts. This because using bolts would be too time consuming and would weigh the structure down significantly more than glue would.
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Fi g . 2 6 : C o n n e c t i o n o p t i o n s rib parts
WEEK 5 1:5 model
Fi g . 2 7 : N e s t i n g f o r t h e 1 : 5 wo r k m o d e l
Fi g . 2 8 : M a k i n g t h e 1:5 model
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The next step was to test the entire structure in a scaled working model made of cardboard instead of MDF in order to get more realistic results. A scale 1:5 model was made to get a more accurate representation of the final design. This model showed some vital weaknesses in the ribs, which were very unstable by themselves. This made the assembling of the model quite difficult. Once all the ribs were in place, however, they worked together and formed a strong structure. It was concluded that the ribs by itself neednâ€™t be dimensioned to be fully stable as long as together they would be strong enough. This was considered enough confirmation that the structure would be able to stand 1:1.
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WEEK 5 Stability After completing the 1:5 model, it was found that the structure was not as stable as suspected. When applying pressure, some parts of the structure deformed somewhat and some displacement could be observed. As the ribs in this model were executed thinner and with less layers than the final prototype would be, it was assumed that the displacement and deformation would be significantly lower than in the 1:5 working model. None the less it was decided that some measures should be taken in case the stability of the final structure should prove not to be sufficient. Two options were therefore developed. The first was a system of cardboard L-shaped profiles that could be attached on four corners of the connections at the crucial points. Bolting these profiles would provide stiffness to the connections and would therefore achieve a more stable structure. If this system would not be sufficient to stabilise the whole structure due to unforeseen forces, the profiles could be adjusted in such a way that tension cables could be attached to them to stabilise the structure further.
Fi g . 2 9 : C o n c e p t f o r c o n n e c t i o n and stabilising the structure with L-profile s
Fi g . 3 0 : C o n c e p t f o r s t a b i l i s i n g t h e structure with tension cable s
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WEEK 6 Wo o d e n s h o e s The problem of the connections between dome ribs and floor ribs, however, still remained. The best solution for this was wooden connections, as cardboard, whether laminated or bolted, would require too much material to provide enough strength and stability. Scale 1:1 models were built to explore the possibilities and at the same time test them. Finally a sort of clamp was generated that would be bolted to connect and strengthen the arch and floor parts. These L-shaped clamps were considered â€œwooden shoesâ€? for the ribs.
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Two types of connections were made on a 1:1 scale: the simple connection where one arch is connected to one floor beam and the more complex connections where two of each type interlock and have to be connected by the joint. The wooden shoes for this work model were made with scraps of wood and joined by six 30 mm bolts and nuts.
Fi g . 3 1 : D e s i g n i n g o f t h e connection
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WEEK 6 C ove r i n g f a b r i c For the covering system of the dome a material still had to be assigned. The fabric that intended as a covering should meet a few requirements. The first being that the fabric is waterproof and can protect against rain and/or snow. The second that it also provides some sort of protection against sunlight and heat. Therefore, a completely transparent fabric or cloth was not suitable. However, to emphasise the structure from the outside view and to be able use natural lighting within, a slightly translucent fabric would be ideal. This was found at â€œBinghamâ€? in Schiedam, a company specialising in sailing fabrics, outdoor advertising materials and coverings. Here a fabric was found that suited the design perfectly; a translucent, woven PVE fabric. To get an impression this fabric was tested on the 1:5 model and the light was filtered beautifully, seen from the inside.
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Fi g . 3 2 : I m p r e s s i o n o f t r a n s l u c e n t c ove r i n g
WEEK 7 Cut ting pat terns
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Meanwhile, the final digital model for the building weeks was refined and fine-tuned, then digitally taken apart and “nested” as flat ribs, to be cut from cardboard. Each piece got a logical number assigned so the cutting, laminating and finally the assembly would be as efficient as possible. The pieces were cut so as to fit the 1.22 x 2.44 m sheets of 6.4mm thick corrugated cardboard. They were fitted onto the sheets by hand as the computer couldn’t handle the action and to use the sheets as efficiently as possible to reduce the amount of waste. To print these cutting patterns on big enough paper to cover the cardboard sheets wasn’t possible due to the high cost. It was decided that the sheets would be divided into A3’s then cut out and put together like a puzzle and used as a cutting pattern for the cardboard sheets. The total number of A3’s needed for the parts of the ribs was 1032. This is excluding the 105 A3’s that were needed for the parts for the wooden shoes, making a total of 1137 A3’s that were cut and put together into 1.22 x 2.44 sheets.
Fi g . 3 3 : Fi n a l n e s t i n g o f the ribs
Aâ€™ Fi g . 3 4 : Fi n a l G r a s s h o p p e r definition
0.76 0.25 1.82
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0.14 2.96 2.68
0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.40
Fi g . 3 7 : S e c t i o n C S 1
Fi g . 3 5 : C a r d b o a r d r i b s parts
0.16 2.83 2.53 0.14
0.18 2.60 2.29
WEEK 7 1 TS 1.2
0.75 0.22 3.00 0.14
Fi g . 3 6 : Wo o d e n f l o o r parts
0.36 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.44
Fi g . 3 8 : S e c t i o n F C 1
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0.13 3.00 2.73
0.77 0.24 2.96 1.81 0.14
WEEK 7 0.35
Rib 6.4 mm CARDBOARD (x3)
Fi g . 3 9 : D e t a i l o f connections
Rib-Arch 6.4 mm CARDBOARD (x3)
Fi g . 4 0 : D e t a i l o f connections
Corner clamp 6mm MDF (x3)
NOTE: Every hole is determined to receive a 6x6x30mm screw and bolt.
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0.178 1 0.1
0.19 0 .13 0.22 3 3
Slab 6.4 mm CARDBOARD (x3)
Slab 6.4 mm CARDBOARD (x3)
Corner clamp 6mm MDF (x3)
0.135 0.067 0.067
Rib 6.4 mm CARDBOARD (x3)
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corrugated cardboard rib dome
pinewood sheet flooring
pinewood wooden shoes
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WEEK 8 B u i l d i n g we e k s
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The first week of the building weeks was used solely for cutting the parts. After the two floor parts were cut from wood, the rest of the puzzled layouts were taped to the sheets of cardboard and the patterns used to cut the 380 individual parts. It seems logical that the symmetry of the design and the use of multiple layers per rib would result in identical parts. However, this was not considered during the nesting therefore too much work to find these identical parts and pair them. In hindsight this cost a lot of extra time and work, because all the parts had to be cut one by one. This was done by hand after a few test runs with the Festool tools, which turned out to take longer and result in less accurate pieces. However, the cutting was all finished in time so it didnâ€™t cause any complications for the further assembly of the 1:1 prototype. Meanwhile, the wooden shoes had been cut from 6 mm MDF using the wood workshop at the Architecture Faculty. They were sorted and bolted, ready to fit the final structure.
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WEEK 9 Lamination and assembly After the cutting work, the lamination process began. Per rib three layers of 6.4 mm were glued together to form a final section thickness of 19.2 mm. The ribs for both directions of the grid were collected and sorted then glued together using wood glue. Soon it became clear that by reducing the thickness of the rib and the amount of layers to three, the ribs themselves had become significantly less strong and more unstable than expected. This didnâ€™t lead to any problems for the floor parts, which were put together quite easily. The wooden shoes were attached to the ends of the floor ribs and bolted together and the floor parts were put in place. As the size of the prototype was 1:1, the ribs were extremely large and turned out to be difficult to handle. The combination of the big size and the weakness of the ribs made the assembly more complicated than expected and in the end couldnâ€™t be done without damaging the individual ribs. The size of the dome was also severely underestimated and more help than planned was needed to manage to put all ribs into place. However, when all ribs were finally assembled and the dome was complete and connected correctly to the wooden shoes and the floor parts, the structure as a whole was much stronger and stable than expected at the beginning. Together the ribs worked as one and their strengths combined made for a very successful shelter.
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The assembly wasnâ€™t timed accurately as the floor parts were assembled at a different time, as were the wooden shoes. A rough estimate, however, shows that the building time needed to assemble the complete structure would be between 1 and 1.5 hours, including more helping hands to keep the structure and the ribs upright while the others were put in place.
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WEEK 9 Dismantling The problem of the weak ribs, however, was still there and became even more apparent when taking apart the shelter. When the first few ribs were removed, several of the remaining ribs buckled under the pressure and broke. It was obvious that the connections of the different parts of one arch were the weak points, as the laminating wasnâ€™t done securely enough. Reducing the thickness of the ribs to three layers proved the fatal mistake, however this could not be helped as the amount of available cardboard provided turned out not the be enough for the original design. Getting this news the week before the building weeks, the rash decision to reduce the amount of layers was made without having time to fully understand the consequences. Looking back, it would have been wiser to keep more layers and instead reduce the size or the scale of the final prototype to save on material.
Us e d m a t e r i al Final list of materials used for the prototype: - 6.4mm x 3 layers laminated cardboard for dome and floor ribs (38 cardboard sheets) - 6 mm MDF for wooden joints between ribs (26 wooden joints) - 19mm brown plywood for floor finishing (2.5 1.22x2.44m plywoods plates) - 6x30mm bolts and nuts for connecting cardboard ribs and wooden joints (284 bolts) Total cardboard weight: ~70 kg Total floor area: ~9 m2
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EVALUATION Design decisions During the process the design decisions were made mainly by testing these with the goal that was defined at the beginning: creating a shelter that could be mass produced, easily and costefficiently transported and quickly built by anyone anywhere in the world using the structural properties of cardboard. Next to this overall requirement, a growing list of parameters and requirements was used to base the design decisions on. These “ground-rules” evolved from the basic requirements to the specific needs and wishes for the final product. The requirements used to test every decision were then as follows: Basic design needs: 1. Capacity to cluster multiple structure with each other, with direct connections 2. Symmetry, to reduce amount of different parts and to simplify process 3. Simplicity in assembly method 4. Rib structure in a waffle grid 5. Floor area of inside space minimum 10m2 Form finding: 6. Dome shaped Digital optimisation: 7. Suitable to be defined in a Grasshopper definition Adapting to disaster area specific needs: 8. Simplicity in shape so as to be understood by user
Ac h i e ve d g o a l s
All ground rules defining the basic design needs were achieved without much difficulty and formed main concept for the project. The form finding process was somewhat messier in a way, probably because the set requirements for it were not as specifically determined. This part of the design process took longer than excepted, since a lot of extremely varying shapes and forms were researched and considered, making it hard to finalise decisions. For this part of the process computer aided design played a big part, as many programs and techniques were explored here, most notably Rhino, Grasshopper and T-Splines. This added a considerable delay, but was none the less useful. Even if in the end the most simple shape of a dome with two sides cut off was chosen, this decision couldn’t have been made without exploring the other possibilities and finding that didn’t meet the basic requirements of clustering possibilities, basic symmetry and easy assembly. Besides this, the shapes didn’t work as well with chosen the waffle grid structure. Furthermore, the final shape of the dome helped immensely in the digital design process. The simpler the shape, the easier to optimise and adapt it. It proved to be a sustainable shape in the sense that is a logical and recognisable form and further development and final assembly and use follow naturally. As it’s a tangible and universal shape, the dome would be most likely to be understood and used well as a dwelling by most. It is also generic and adaptable, which makes it suitable for any location in the world. The straightforward shape would lead most people to understand the assembly procedure without any building knowledge and would also allow for easy adaption to new living circumstances and surroundings.
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During the process and with the final prototype the main goal - to creating a shelter that could be mass produced, easily and cost-efficiently transported and quickly built by anyone anywhere in the world using the structural properties of cardboard - was achieved for the biggest part. Most set goals that were defined with the above mentioned set of requirements were also met and were an efficient tool to give shape to the design process.
EVALUATION Wh a t we n t r i g h t Process The design process for the cardboard shelter was smooth and without any big obstacles. It is quite common to follow a process that is not a straight line but a continuous curve that turns back on itself to reconsider previous steps and this is basically how the process occurred. The process happened very organically and with continuous progress from the abstract first concept to exploring and discarding ideas to the actual building of the 1:1 prototype. Main influence on the smooth process was the simplicity of the shape for the shelter, as this allowed experimenting and developing easily, without compromising the final design. It is a straightforward shape and therefore easy to adapt to many needs. Cutting Hand cutting the pieces seemed an enormous task at first and was maybe a bit controversial but was necessary due to limited means. Though a lot of parts of the ribs had to be cut individually, which wasn’t the most efficient way to do it in the end, it didn’t take as long as expected. When testing the use of tools for this preparation process it was also found that cutting by hand would lead to a much higher accuracy of the parts. The downside was the physical strain of this task, but this change from the work of digitally designing was actually much appreciated. Of course if this shelter were to be actually produced in large quantities to be used for emergency situations, cutting the parts by hand would be out of the question. This was merely the best way to do it for the purpose of creating the prototype, but would be done automated when needed in bigger quantities. In this case it also enhanced the experience of creating from scratch a design and finally building it into a 1:1 model and gave extreme satisfaction. Needless to say this satisfaction would not occur if the design would be fully produced by machines. Building time
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Once all the parts were cut and laminated into the structural ribs, it only took around 1 to 1.5 hour to completely assemble the shelter. Considering the size of the dome and the structural performance, this is an extremely fast assembly time and can be seen as huge advantage, speeding up the process of setting up emergency shelters significantly. This of course does not include the covering of the shelter, but even this would take hardly any time as it’s a fairly simple process to cover the dome with the provided material. Some problems during assembly that could have been avoided were the underestimated size and height of the dome and the weakness of the ribs when handled separately. This will be explained below.
Wh a t c o u l d b e i m p r ove d Material The chosen material from the beginning of the process was cardboard, yet it turned out in the end that for a waffle rib structure this might not be the perfect material. It was found while manufacturing the parts and assembling the final structure that cardboard is extremely likely to fracture upon any impact. It is fragile in the sense that is has a low fracture toughness and will damage easily, e.g. when handled or transported. Although the material worked perfectly for the final structure and it’s easy to cut and very lightweight, a material such as wood would perform the same way without being susceptible to damage during the building process. Thickness of the ribs Because concessions were made for the size and thickness of the ribs, they turned out to be much less strong than expected. These decisions had to be made last minute due to the amount of material needed not being available anymore. Because of the last minute change,
EVALUATION the decisions were made rashly and without considering the effects thoroughly enough. The thickness of the layers were downscaled from 5 layers of 7.2mm cardboard with a total thickness of 3.75 cm, to 3 layers of 6.4 mm cardboard with a total thickness of 1.92 cm. The thickness of the ribs was almost halved. Besides this turning out to be too weak when handling the ribs separately (in the final structure they worked perfectly together and were strong enough), by using 3 layers instead of 5 the connection points where the parts of the rib were laminated together became extremely weak and in some cases broke completely. Looking back it would have been wiser not to change the thickness of the ribs but to scale down the size of the entire shelter in order to save material, for example by building it on a 1:2 scale. Lamination As mentioned previously, the weak part of the ribs turned out to be the overlapping connections that were laminated together. This was mainly because the thickness was downscaled to 3 layers instead of 5, but it is questionable if even 5 layers would have made a strong connection. It might have been considered to add a stronger material to those specific parts such as plywood or MDF. Another option would be to design a different overlapping system, with every single layer overlapping a different amount, instead of every alternating layer. Size of the dome
The size also proved to be a slight problem during the disassembling of the shelter. The ribs worked very well together as a structure and were quite strong, but as mentioned before as soon as they were handled separately they became very weak objects and very susceptible to damage. When taking apart the structure, the ribs couldnâ€™t be handled as carefully as intended due to the enormous height of the dome. This led to a lot of ribs bending or fracturing. Again, scaling down the height of the dome could have prevented this from happening, but also choosing to build the prototype at a 1:2 scale would have made a big difference.
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Once the shelter was built into a 1:1 prototype it became clear that the height of the dome was considerably bigger than necessary. The chosen height was a direct effect of the height of the entrances, but in hindsight this could have been adapted easily without affecting the pure shape of the dome. While the scale and space of the floor plan turned out as expected and of a comfortable size, the height of the dome felt out of proportion and added a lot of useless space. Furthermore, it made the assembly much more difficult as more people than expected were needed to help build the structure and ladders and chairs were required to reach the top parts of the dome. As Dutch people are supposed to be the tallest, this meant that it would certainly not work in other parts of the world. So it would have been a good idea to somehow reduce the height of the dome without compromising the overall shape, the height of the entrances and the floor area of the shelter.
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Overall the final design met the set goal of creating a shelter that could be mass produced, easily and cost-efficiently transported and quickly built by anyone anywhere in the world using the structural properties of cardboard. Besides a few small design details that could have been developed better, the concept and final prototype proved to meet the requirements and expectations. The biggest defeat was the weakness of the separate ribs and the fracturing during disassembly. By taking the forced but rash decision to downscale the thickness of the ribs without considering alternatives, the performance of the shelter was compromised. Looking back this could have been solved better by either adjusting the height of the dome or changing the scale of the prototype. It is now clear that more layers and a bigger rib thickness are necessary to make this structure work with cardboard as a structural material. Besides this, however, the final shelter worked beautifully and gave a whole new perspective to creating emergency shelters for refugees in disaster areas. The concept is simple and structural, the parts relatively easy to manufacture and cheap to transport in flat packaging and the assembly method extremely clear and fast, making it a perfect solution to the design problem.
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