P O R T F O L I O BENVGF12 THESIS PORFOLIO: INITIAL PROJECTS S T U D E N T: M A R I A - E L E N I PA PA N D R E O U RC101- SINGLE POUR HOUSE MARCH DESIGN FOR MANUFACTURE THE BARTLETT SCHOOL OF ARCHITECTURE DIRECTED BY: JELLE FERINGA | MATTHIJS LA ROI | TIM LUCAS
CONTENTS 00. a brief inrtoduction
C OM P ONE N T D E S IG N - TERM 1 01. getting familiar with concrete 02. design research 03. form-finding with RV 04. further design of the shell structure 05. fabrication scenarios
F OR MWO R K S T U D IE S - TERM 2 06. compare & contrast 07. gridshell prototype 08. cable-net in tension 09. hot-wire foam cutting 10. casting experiment 11. house design 12. what’s next
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07 08 12 14 18 20
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00. A BRIEF INTRODUCTION FORCE INFORMED ARCHITECTURE There have been numerous attempts within architectonic research to blend engineering and architecture. How could statics be nested into a shape, structural calculation enrich creativity or technical thinking guide and define the synthetic process and conformation of a building? Many methods have been developed for these questions to be answered. From experimental form-finding to digital simulation and structural optimization, architects and engineers have tried merging their synthetic abilities and technical knowledge. In the work presented below, both in Term 1 and Term 2, I investigate how the implementation of digital tools can give us information about the force flow of a structure to obtain its efficient shape. An attempt is made to explore the virtue of structure as a primary component of architectonic composition, by focusing on the methods of form finding and digital simulation. The conception of structural properties from the early stages of the design constitutes a key element of the synthetic process. As the main material of the RC101 cluster brief is concrete we will start in Term 1 by studying compression only structures. What does funicular mean and how boundaries and supports affect the shape of a volume? How does concrete behave and how carefully a mold should be designed and treated? In Term 2, we will continue with a deeper investigation of formwork systems. We will conduct digital simulations to create systems that work in tension and are able to support large concrete volumes with the minimun material arranged in such way that it represents its stronger state. Last but not least, we will try not only to be efficient in terms of structure but also on fabrication methods. Material cost and waste, on site labour, transportation issues, accuracy, assembly and cast time are only a few of
Heinz Isler’s examples of the endless forms possible for shells,
the parameters that we took into consideration for the realization of these
from the 1959 IASS conference (Isler, 1960)
projects.
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Parametric FEM Solutions for meshing complex geometries. The new central station for the Stuttgart 21 infrastructure project by Ingehoven Architects with Frei Otto features complex double curved concrete geometries.
Building in concrete with a knitted stay-in-place formwork: Prototype of a concrete shell bridge Popescu M., Reiter L., Liew A., Van Mele T., Flatt R.J. and Block P - ETH Zurich
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COMPONENT DESIGN DESIGN STUDIO PROJECT term 1
01.
getting familiar with concrete
02. design research 03. form-finding with RV 04.
further design of the shell structure
05. fabrication scenarios
01. GETTING FAMILIAR WITH CONCRETE
COMPONENT DESIGN Our first task was to design a component for our first casting workshop. They design would be a simple origami form. My intention was to make and object, which when multiplied, can form a wall that could either carry vegetation or serve as a bookcase or in general provide variations of lighting.
references: Design robotics group, Harvard GSD, (1) Robotic casting workshop Japan, (2) Robotic casting workshop Gratz, (3) ceramic design project by Linda Zhang and Jenny Hong // (4) Archi Union Architects, AU Office and Exhibition Space
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aggregation of components
origami exploration
cardboard test model
unrolled mold surface for lazer cutting
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MOLD DESIGN I chose plywood for the material of the mold. It was easy to assemble and to demold. The main problem was that because wood is opaque there is no way to guarantee that the concrete has flown everywhere within the mold, especially in such a complex geometry that I chose to cast in. We can see in the resultant component that there is discontinuity of the material in some corners. Moreover the surface has a nice rough finishing but at the same time it is too brittle.
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CASTING WORKSHOP In our first casting workshop we used a mix of one part fast-dry cement, 3 parts sand and water. Below are some pictures of the process as well as the result of the casted object.
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02. DESIGN RESEARCH
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FREEFORM VS. FORM FOUND In search of a general form that would be comprised by smaller concrete components, I conducted a structural analysis to understand the structural behavior of shells. I used Karamba software for the calculation and visualization of the deflections under gravity loads of two given
rhinoVault surface
freeform surface
models; a freeform surface and a form-found shell. The material I used for the simulation was concrete C35/45.
a
b
c
Displacement values (a) and deformed mesh in plan (b) and side view (c)
SETTING CONSTRAINTS - THE HOUSE CONCEPT To delimit the design space of my digital experiments I realised I have to put some constraints in my simulations. Can we design a vault structure using rhinoVault, where the form, apart from structural, produces a functional efficiency as well?
support points could create more private areas where necessary
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computational workflow diagram
03. FORM FINDING WITH RV perspective
bird-eye view
form graph
force graph
force (kN)
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EVALUATION OF THE RESULTS After numerous trials with Rhino Vault I finally reached a shape that would serve my housing goals. As is indicated in the section diagram, in the big open space of the front side, the living areas are located and they are directly related to the patio. The back side of the patio’s perimeter is lowered to the ground to provide privacy to the sleeping areas. On the right side the vault, support points to specific places create a solid front where the bathroom would be located.
base surface
form diagram
form graph
force graph
6 5 4 3 2 1 0
kitchen
patio
bedrooms
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bathroom
living room
MESH OUTPUT An attempt is made below to apply a component (a) and a brick pattern (b) on the mesh geometry. The resultant mesh of rhino vault is not organised in such a way that I can directly use it for further design of my shell structure. Further manipulation of my digital model is necessary to organise my geometry in such a way that I can continue my parametric workflow. How can we extract useful geometries from the resultant shape?
By using directly the mesh output of rV for further design of my shell I get a random division & orientation of bricks
a
b
a
b
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CONVERT TO SURFACE Below there is a definition of converting the rV output to a valid surface that we can analyse and proceed to further design & construction solutions. The idea behind this grasshopper definition to get a surface out of the mesh is inspired by the falsework used to build such structures. First we create a dense planar grid (a), then we project it to the mesh (b) and finally we use this 3d set of curves to create a surface. On the last figure (c) we can see the 3d shape of the lofted planar and projected lines.
a
b
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c
03. FURTHER DESIGN OF THE SHELL STRUCTURE
TEXTURE Now that we have obtained a valid 3d geometry of our compression only vault we can proceed to applying construction elements to its surface. A rough finishing is proposed for the interior of the shell in order to fix acoustical problems of such curved space.
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COMPONENT DESIGN Considering the initial goal of this term I decide to break the surface into individual interlocking components. When they are placed together they create the shell structure.
vertical & horizontal contours to split the surface
component boundaries
ACOUSTIC TILES REFERENCES (1) ‘sleath’ by 3d wall panels, (2) One brick type rotated into 6 different position by Klink and Petersen Tegl, (3) wooden decorative wall, (4) LAINE, acoustical panel by Anne Kyyrö Quinn, (5) acoustic tiles in the Elbphilharmonie Hamburg by Herzog & de Meuron, (6) Scale by Filz Felt, (7) 3d pixel by Beau
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05. FABRICATION SCENARIOS
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POLYURETHANE FOAM MOLDS Two 3d models were prepared for CNC milling. One contained 3 components and the other a scaled model of the whole shell structure.
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PREPARATION OF THE MOLD There are certain important steps to be taken into consideration for the milling process and preparation of the mold out of Polyurethane Foam. First, measuring the block is of high importance. As we can see in the second picture there is a big difference between each side of the foam block volume. This extra material needs to be removed in order to achieve high accuracy. After the geometry has been produced, the surface that we will cast within needs to be sealed as is shown in the last picture. The use of PVA glue was not the best choice since its is a water disolved material. As a result demolding was quite a challange for both models. Since the scaled model of the shell was really thin, it broke while I was removing it the foam. two-part mold digital model
fixed tolerances for the tiles to interlock
CONCRETE RESULTS A fibre reinforced premix with no aggregates was used this time for casting. The mix was fluid enough to reach all the parts of the complex geometry produced. The material result is a nice matte texture which has not changed through time.
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STEPWISE CONSTRUCTION OF THE SHELL If every concrete component is unique then milling is not the most efficient way of production. So another way of construction in layers is proposed. The mold is comprised by a steel formwork for the interior side of the building and the insulation for the exterior side. The distance between them is controlled by spacers. The process is described below: 1. we fix the steel formwork and insulation material 2. we pour the concrete 3. once the concrete is dry, we remove the formwork and place it on top of the compacted concrete 4. we pour the second batch of concrete 5. once the construction is finished, the exterior sur-
1
2
face is sprayed with concrete
sprayed concrete steel formwork
insulation
poured concrete
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5
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FORMWORK STUDIES DESIGN STUDIO PROJECT term 2
06. compare&contrast 07. gridshell prototype 08. cable-net in tension 09. hot-wire foam cutting 10. casting experiment 11. house design 12. what’s next
06. COMPARE & CONTRAST DESIGN & CONSTRUCTION REFERENCES In the examples presented in this chapter we look at two completely different projects both in terms of design approach and construction methods. These two projects follow opposite principles but yet have a quite similar geometrical expression.
Toyo Ito & Associates Crematorium in Kakamigahara The main concept of the design and optimization process of this building is a smooth, hill-like roof. The algorithm used to improve its structural performace iteratively seeks for possible design alternatives, with respect to the supports, the perimeter of the roof and a structural principle. This building exemplifies the optimization process as a means of design exploration, in a way that priority is given to the form rather than mechanical, economical or environmental properties. Same logic was applied on its fabrication method. Large pieces of wood were bent or milled with CNC on specific shapes to create this rigid and unique formwork. The cost, labor and waste of material behind the creation of this temporary structure was significant.
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Block research group ETH Zurich NEST HiLo The roof of HiLo is a thin shell structure to be constructed using a prestressed, cable-net and fabric formwork. The shape of the roof is largely determined by the geometry of its boundary edges as well as its supports. Its tickness is variable and reduced in accordance with a load simulation that was applied in the resultant form-found geometry. The reusable and lightweight mixed
cable-net
and
fabric
formwork system that was used for the construction of this project allows the creation of doubly curved thin shell structures without the typically associated high labour and resource investments. The project aims to reduce construction cost of shell designs. It is easily transported and there is no need for scaffolding or temporary foundations.
KEY DIRECTIONS As is evident there are numerous ways of solving the construction of curved concrete geometries. Since the material itself is relatively cheap, the production of the formwork and scaffolding in most concrete buildings is the biggest expense in terms of material price, transportation and labor. Furthermore, when we have to deal with a unique digitally generated shape the cost and waste on producing it is even higher. The Crematorium’s construction methods revealed to me a great challenge that needs to be addressed and HiLo’s roof a big inspiration in terms of efficient, weight, reusability and adaptability of formwork solutions.
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Material & geometry studies for a geometrically adaptable and resusable formwork
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07. GRIDSHELL PROTOTYPE GENERAL DEFINITION keeping edge lengths of a quad mesh equal This aim of this research is to create an adaptable formwork system with standarized components that could take any shape and then be reused in another project. To achieve this we try to analyse a solid shape to a mesh with equal edge lengths. We developed a scrip that starts from a flat mesh grid and then it is draped over a solid shape. The result is a mesh that describes the initial solid shape with node to node distance fixed but variable angles between the edges. The logic behind the digital simulation is explained below:
p
Set N to 1 to start the simulation. Raise to 10 to increase the strength constraint and maintain curves original length after the simulation
[raise 10 to the power of N]
length lines
10N
strength
gravity force
nodes
[smaller integer for strength input > curves deform]
solid geometry
[larger integer for strength input > curves try to maintain their original length]
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solver
1<N<10
equal length curves on solid geometry
runs.
HYPERBOLIC CORE applying the concept to a pre-defined form
flat ceiling
The design brief of this term was about the creation of a structure that would be defined by a hyberbolic column. We produced a geometry in which continuity is
freeform part
maintained from the ruled surface of the hyperbolic paraboloid to the flat ceiling. We choose to run our drape simulation definition to the intermediate freeform part of
ruled surface
the composition.
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7.
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3.
6.
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UNIVERSAL JOINT standarizing the components We designed a universal joint that could accommodate almost every angle in plan and section. This joint would have slots to receive equal length steel pipes. For our 1.10 model its was not feasible to create such components so we 3d printed all 110 unique joints to essemble the mesh. The pipes were created out of copper rods.
section
plan
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SHUTTERING MATERIALS potential options to seal the gridshell The formwork system could be shuttered with various materials in order to act as a mold. The following diagrams show some material proposals such as textile and foam that could be combined with the steel gridshell. We will invastigate both how textile patterns can be produced and how foam blocks can be shaped in accordance with the desirable geometry.
1.
2. 1.
steel gridshell steel gridshell
3. 2.
3.
foam foam
foam
foam
textile textile concrete concrete
textile
concrete
concrete
concrete
concrete
textile textile
steel gridshell steel gridshell
foam
textile
foam
steel gridshell steel gridshell
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08. CABLE-NET IN TENSION METHOD IMPROVEMENT introduction of a stronger technique that can support concreteâ&#x20AC;&#x2122;s heavy loads After assembling the rectangular gridshell of the mixed system of rods and joints that is presented in the previous pages we realised that it was rather weak and likely unable to support the weight of the concrete. Consequently, we started searching for a stronger solution that would serve our goals. By physicaly and digitally constructing a system that works in tension we understood that a cheap, lightweight and resuable material such as steel wire when prestressed and fixed properly can generate a variety of geometries and carry significantly heavy loads. We created a parametric definition that used a radial rather than a rectangular grid to facilitate fabrication.
Test model with cotton string to understand how a mesh in tension works
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DIGITAL DEFINITION parametric definition of the tension simulation & the construction process
top anchor points
creating the mesh
generating the base for a radial grid
intersection of the base division with the roof perimeter
producing a surface by connecting top & bottom anchor points
verctical force to the nodes
mesh in tension
geometric simplification for fabrication
construction elements
applying inverse gravity force to the points of the mesh
setting the rest length of the lines to be smaller than the initial length
equalizing the different lengths of the resultant geometry
orienting consctruction details to the resultant geometry
boundary conditions base of the column & roof perimeter
radial division
VARIATIONS OF THE SYSTEM applying the concept to an off-centred geometry or a 2-columns composition
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Final model of a radial grid in tension
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Details of steel wires, joints, pipe spacers, fixtures and turnbuckles
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DETAILS The system we propose is covered with a waterproof textile. Foam blocks which will be the insulation of the building are placed in a certain distance from the textile. These two materials form the mold where the concrete will be poured. Below are some details that show how the
2. textile fixture
1. insulation foam block
system could be built in real scale.
steel pipes wires foam block
3. joint detail
4. tension archor
textile textile fixture steel joint
steel beam tension anchor bolts
steel pipes wires steel joint
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Physical model scale 1.10
Construction process of the mesh
Initial system before stretched
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Sewing process of the PVC Textile
Tensioned state after all the components are pulled
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09. HOTWIRE FOAM CUTTING SCALE 1.10 casting experiment We used a KUKA robot to hot wire cut the second part of our mold out of polysterene foam. We simplified the geometry into a ruled surface and split it into 4 pieces for our first casting experiment. After we cut the pieces we glued them and sealed them with latex in order to be waterproof. Then we covered the surface with fibreglass tape and placed on top a steel mesh for the reinforcement of the concrete. Bellow is the toolpath the robot will follow to cut the pieces and on the next page some pictures of the final result of the foam pieces glued together.
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5.
9.
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SCALE 1.1 prestressed foam block system In a 1.1 scale the geometry of our shell would be cut in smaller foam blocks. These would have an interlocking system on the sides in order to be assembled easily. Steel wires would pass through them in two directions and would be stretched at the ends to hold the whole system in place. Because tension is applied displacements due to the pressure of the casting process would be eliminated.
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2.
9.
10.
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3.
3. Bottom layer: Foam 6.
1. Hot wire cut foam blocks INSULATING CONCRETE FORM (ICF) PANELS 6. 2. Concrete
details of the3. Hot formwork system wire cut foam blocks 4. Cable wires
7. Nut 8. Tread rod
5. Steel pipes
9. Foam piece
6. Panels join to connect the
10. Metal plate
Even though in our physical model we will test a combination of PVC textile and foam as a mold, we briefly investigate the possibility of having three layersThe together. on both sides foam. same logic of a system that works in tension applies here as well. Once on site the wires that run inside the foam
blocks are stretched giving the final shape of the volume. There are spacers that assure that the foam blocks will stay in a certain distance.
Section of the erected system
Physical model of the insulation panels in tension / scale 1.50
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Tensioned foam blocks
IICF PANELS CF PANELS
details of the formwork system
Tensioned foam blocks Tensioned foam blocks details of the formwork system 4. 5. details of the formwork system
1. Top layer: Foam 6. 5. 5.
1. Top layer: Foam 1. Top layer: Foam
6. 6.
6.
2. Middle layer: Concrete
2. Middle layer: Concrete 2. Middle layer: Concrete
4. 4.
6. 6.
3. Bottom layer: Foam 3.3.Bottom Bottomlayer: layer:Foam Foam
6. 6.
1. Hot wire cut foam blocks Hotwire wirecut cutfoam foamblocks blocks 1.1.Hot 2. Concrete 2. Concrete
Concrete 3. Hot2. wire cut foam blocks
Hot wire cut foam blocks 3.3.Hot wire cut foam blocks 4. Cable wireswires 4. Cable 4. Cable wires Steel pipes 5. Steel5. pipes 5. Steel pipes 6. Panels joinconnect to connect the 6. Panels joinjoin to 6.three Panels connectthe the layers to together. threethree layers together. layers together.
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6.
6. 6.
7. Nut
7. Nut 7. Nut 8. Tread 8. Tread rod 8. Tread rod
rod
9. Foam 9. Foam piece 9. Foam piece
piece
10. Metal plate 10.plate Metal 10. Metal
plate
10. CASTING EXPERIMENT SCALE 1.10 pouring concrete from bottom to top We poured concrete through a plastic tube of 50mm diameter at the centre of the structure. The concrete mix contained sand, cement, 10mm aggregates, water and plasticizer. The casting process took place from bottom to top. Some deformation occured due to two reasons. The casting didnâ&#x20AC;&#x2122;t happen in one go and the fixtures got loosened as the pressure from the concrete increased. When our mold was half full we started pouring from the corners. After the casting process finished the concrete was left to set for approximately 3 days. Then we flipped the model to remove the wooden frame, the PVC textile and the wiremesh. The foam was not removed. The concrete finishing was glossy the first day but it got matte during the next days.
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11. HOUSE DESIGN APPLICATION OF THE METHOD Even though the building method proposed in this exercise is still in an experimental stage we invastigated briefly how it could be transformed into a fully functional private residence. The concrete core of the house is used as the main structural system and design element. The facade is simple glazing. All uses are arranged around the core apart from the bathroom which is placed inside the concrete element.
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HOUSE DESIGN +4.50
+3.70
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0
0.5
1
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5
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Odico Formwork Robotics - Robotic Hot-Blade cutting
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12. WHATâ&#x20AC;&#x2122;S NEXT The methods presented in the projects above tried to approach and tackle problems of the contemporary construction industry within a very tight timeframe. In the short period of 6 months we had the chance to get familiar with novel fabrication techniques and understand key factors of translating something from a digital model to the physical world. Having powerful computational tools at our command, we can generate a wide range of possible design solutions which correspond to specific performance. Finding ways to enhance the utility of those tools by using them in conjunction with other technologies like robotic fabrication and additive or substractive manufacturing is one of the biggest challenges in the contemporary construction industry. In this respect, through the next months I would like to achieve a highly integrated computational design and fabrication process that follow two main directions: collaboration of multiple robots for the efficient production of architectural components and minimizing material waste.
SYNCHRONIZATION OF MULTIPLE ROBOTS During this term I had the chance to comprehend how complicated it is to create a toolpath for large scale architectural components that will be produced by a 6-axis robot synchronized with a 2-axis rotary table. The limitations of the robots or the end effectors are numerous but also the potential of the process is immense. The results I got from the digital fabrication processes I used were highly accurate but the process was incomplete, in the sense that creating a element which can be used in the construction of a building is way more complicated than just transfering a geometry from the digital to the physical world. There is always some further manipulation that is necessary (especially if we are trying to create some sort of formwork) such as detailing, connections of multiple elements etc. Moreover, even though hot wire cutting is a way quicker process than milling, there are some geometrical limitations on what we can achieve with a the hotwire setup. My interest lies in a group of robots that will perform synchronized activities. Through this process we could overcome geometrical limitations or make the fabrication process of construction elements more complete. For example, the combination of a milling and a hot wire end-effector can produce a bespoke ICF panel as presented in the previous chapters very quickly since the one robot will be cutting the unnecessary material and the other will be drilling the holes where the steel wires will pass through. Another way of using a group of robots could be in a setup like the one in the picture on the left that allows the creation of double curvature (instead of just a ruled surface) out of one block using a linear tool like a hot wire or a blade.
MINIMIZING MATERIAL WASTE ON ROBOTIC FABRICATION What I would like to achieve through this direction is that for a given material block and a specific end-effector how can we stack the components that need to be cut inside the volume of the given material in order to have minimun offcuts. At first glance this direction seems purely computational but there are various challenges in the physical world to be taken into consideration when trying to cut multiple components out of one block. For example, how can the robot run in automatic mode to achieve time efficiency while assuring that it will not damage the final geometries. I consider hotwire foam cutting a very interesting process but at the same time material wasteful and I believe that through this program we are given the opportunity to give answers to the aforementioned questions.
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ACKNOWLEDGEMENTS The above work was supported by Peter Scully, Vincent Huyghe, William Victor Camilleri, Alex Mc Cann, Melis Van Den Berg and many other nice people at the BMADE. Thank you very much for your generous help!
THAN K . YO U