Course director : Dr.Elif Erdine
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Emergent Technologies and Design
Founding director : Dr.Michael Weinstock
Studio Tutors : Abhinav Chaudhary, Alican Sungur, Eleana Polychronaki, Lorenzo santelli
REVOLVED ASSEMBLY Group 04 Devaiah Ponnimada Emergent Technologies and Design - Design and Technology
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Elliot Ouchterlony
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Emergent Technologies and Design - Design and Technology
Contents
CONTENTS
Emergent Technologies and Design - Design and Technology
Contents
1.0
Abstract
2.0
Material Intelligence Material transition
3.0 3.1
Material Adaptation Linear assembly Radial assembly
4.0 4.1 4.2
Assembly Full scale assembly Jig Load-testing
5.0 5.1 5.2 5.3
Pseudo - Code
6.0
Karamba Analysis
7.0
Final assembly Conical Assembly Global Geometry
8.0 8.1 8.2
Conclusion
9.0
2
3
Emergent Technologies and Design - Design and Technology
Abstract
ABSTRACT The design and technology brief was to scale up an existing design using a new material. In our case, a revolved assembly originally fabricated from polypropylene and paper was to be scaled to twice its original scale . Through a series of tests which incrementally built on one another, we gained an understanding of veneer as a material and methods of assembly for our specific design. Gaining an understanding of veneer through material testing prompted a complete redesigning of the structural system. As veneer is a tempermental material, throughout our design process we continually tested the material both physically and with Finite Element Analysis. In order to constrain the veneer components into positions where they were unable to split or break while also providing structure, we designed and incorporated specific hardware. The design’s complexity created a need to analyze our assembly process and design systems and processes to fabricate the system. We designed jigs and fixtures to constrain the components while they were being assembled. Once we had gained an understanding of our material, we were able to test and calibrate how elements like tension affected the full scale assembly, its load bearing capacity and rigidity.
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3.1 . Material transition
Fig 3.0 - Paper model ( bootcamp )
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Fig 3.1 - Polypropelene model ( bootcamp )
Emergent Technologies and Design - Design and Technology
3.0 . Material intelligence
Material Intelligence Material transition The change in scale and material prompted a complete redesign of the structural system. The previous design was fabricated in paper and polypropylene. Based on the materials flexibility, the structural system was created using flat patterns that were folded and curved in multiple directions. Because of the veneer’s grain direction and flexibility, one of the first decisions we made was to not bend or curve our structural components more than once ( Fig 3.3 ). This drastically reduced the stress within each part.
Fig 3.2 - multiple bends
Fig 3.3 - single bend
Fig 3.4 - initital prototype ( paper)
This change created a demand for a new system to join the components end to end. We explored various methods that this could be done with using only the veneer components and not adding a second material. Initial testing with paper, creating overlapping finger joints where four components met at the end proved to create a somewhat successful joint. The joint system worked well under compression and was flexible enough to distribute loads through multiple components.
Fig 3.5 - initital testing (paper) Emergent Technologies and Design - Design and Technology
Fig 3.6 - initital testing (veneer) 6
3.0 . Material intelligence
Once confident the structural system was worth moving forward, we began to do testing individual components to determine appropriate width to length proportions for the components. We also performed these tests in Karamba, calibrating the system to our material as early as possible
1:3
1:6
1:5
1:4
1:7
1:8
1:9
1:10
Fig 3.7 - test for proportions
350
Length (B)
Height (C)
Defelection
Length (B)
300
350
250
300
200
250 150
100
100
50
50 0
1:10
1:09
1:08
1:07
1:06
1:05
1:04
1:03
1:10
1:09
1:08
1:07
1:06
1:05
1:04
Defelection
12
5
3
2
1
0
0
0
Defelection
12
8
6
4
3
2
1
0
Height (C)
71
64
57
50
43
36
29
21
Height (C)
71
64
57
50
43
36
29
21
Length (B)
248
223
198
175
148
124
99
74
Length (B)
248
223
198
175
148
124
99
74
Fig 3.8 - physical analysis 7
Defelection
200
150
0
Height (C)
1:03
Fig 3.9 - karamba analysis Emergent Technologies and Design - Design and Technology
4.0 . Material Adaptation
Material Adaptation Linear Assembly Following deflection analysis we tested the system in linear assembly.
Fig 4.1 - linear assembly
Fig 4.2 - tension strings
Fig 4.3 - finger joints
- Tension string was incorporated within the cells so as to keep the finger joint under compression. Strips of veneer were added to the top and bottom of the assembly to constrain the curved components movement. - Finger joints proved to work effectively in a linear assembly. Emergent Technologies and Design - Design and Technology
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4.0 . Material Adaptation
Radial Assembly Based on the principles gathered from the linear assembly we tested the system in radial assembly.
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Emergent Technologies and Design - Design and Technology
4.0 . Material Adaptation
Fig 2.4 - assembly
Fig 2.5 - joints tend to disassemble
Fig 4.6 - tensioning system
Observations • As a result of the components stress, the finger joints tended to disassemble. Tension components, running from one joint to the joint on the opposing side were incorporated to constrain the joint into the correct position. This addition also required a node in the centre of the assembly, constraining the tension cables. ( Fig 4.6 ) • Manual assembly of the system proved to be difficult as the component were under stress. From this we began to discuss jigs and fixtures to constrain components to ease the assembly process. Emergent Technologies and Design - Design and Technology
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4.0 . Material Adaptation
Observation
Fig 4.7 - finger joint failure
• Veneer under tension were splitting along the grain. When we analyzed this issue we found it was occuring in the same place in every component. The issue was an area that was resisting curvature while being unsupported by the joint. 11
Emergent Technologies and Design - Design and Technology
4.0 . Material Adaptation
splitting point unsupported area
finger joints for support
Unsupported area
Finger joint optimization
Fig 4.8 - diagram indicating finger joint optimization to minimize failure
Fig 4.9 - test for improved finger joint design
Observation • We tested a finger joint design which aimed to resolve grain splitting by reorienting the finger joints such that the area in question was supported. This proved to be successful. Emergent Technologies and Design - Design and Technology
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5.0. Assembly
Assembly Full Scale Assembly Our next test was to scale the assembly to the size we intended for the final structure. • In order to simplify the assembly we built a jig which helped to orient and constrain the components during assembly. • The assembly was load tested physically and in Karamba.
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Emergent Technologies and Design - Design and Technology
5.0. Assembly
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5.0. Assembly
Fig 5.1 - the jig
The Jig In order to facilitate assembly we designed a jig. The system was built from the same dimensions as the assembly so as to hold the components in place during assembly. We fabricated the system from laser cut MDF board. The jig also proved to be useful during load testing. Flipped from the bottom of the assembly to the top, it provided a platform to hold weight.
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Emergent Technologies and Design - Design and Technology
5.0. Assembly
Fig 5.2 - physical load test
Total Load
Span Height
Deflection
Total Load
1600
1400
1200
Overall load (gms)
Overall load (gms)
Deflection
1600
1400 1000 800 600 400 200 0
Span Height
1200 1000 800 600 400 200
50
75
100
125
150
0
Deflection
10.5
15.5
17.5
26
32
50
75
100
125
Deflection
11
15
19
22
26
Span Height
208
202.5
200.5
192
188
Span Height
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205
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198
194
Total Load
400
600
800
1000
1200
Total Load
400
600
800
1000
1200
Fig 5.3 - physical analysis
150
Fig 5.4 - karamba analysis
Observation Based on the karumba testing we discovered that adding tension to the system increased the load capacity, reducing deflection. Because of this, we planned to incorporate an adjustable global tension system to the final assembly.
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6.0 . Pseudo Code
Pseudo - code
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1. Define arcs of global geometry
2. Determine the span heights
3. Generate arcs for all span heights
4. Generate surfaces of the spans
5. Individual half spans
6. Flat pattern
Emergent Technologies and Design - Design and Technology
6.0 . Pseudo Code
7. Generate the global geometry
The global geometry was generated by mirroring the half section spans and patterning them to the specified number of cells. This assembly was then mirrored to create the full, symmetrical assembly. The full assembly was used for visualization and FEA testing.
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7.0 . Karamba Analysis
Karamba Analysis
Fig 7.0 - karamba analysis showing deflection
Prior testing of individual components and smaller assemblies informed the analysis of the full scale assembly. Information generated by the analysis informed decisions on component widths and number of patterned cells to minimize deflection within the assembly.
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Emergent Technologies and Design - Design and Technology
8.0 . Final assembly
Final Assembly Conical Assembly In this test we assembled the first floor of our model to analyze the components in conical assembly. We tested the cleat bracket along with the adjustable tensioning node. Both proved successful, allowing us to move forward with the full scale assembly.
Threaded rod
Master node
Node
Cleat bracket
Assembly jig
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8.0 . Final assembly
Cleat Bracket Previous testing had proven that adjustment of tension cables was essential to structure and ease of assembly. Based on this we designed a bracket which would orient the joints into position while not overcontraining them while providing an interface to easily tension and detention system. Based on the complexity of the part we decided to 3D print the component. Cleat
Assembly
Knot
Fig 8.1 - cleat bracket schematic
Fig 8.2 - 3D printed cleat bracket 21
Emergent Technologies and Design - Design and Technology
8.0 . Final assembly
Fig 8.3 - components for assembly
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8.0 . Final assembly
Fig 8.4 - assembly process images
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Emergent Technologies and Design - Design and Technology
8.0 . Final assembly
Fig 8.5 - global tensioning system schematic
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8.0 . Final assembly
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Emergent Technologies and Design - Design and Technology
8.0 . Final assembly
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8.0 . Final assembly
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Emergent Technologies and Design - Design and Technology
9.0 . Conclusion
CONCLUSION Due to the complexity of the system, it was challenging to understand the dynamics of the full scale assembly until it had been completed. If we had done more testing, If design elements such as adjustable tension had been incorporated into the design earlier, and we had done more testing to understand they system the final assembly may have had the opportunity to be more dynamic. Greatly increasing rigidity under tension, and decreasing rigidity when tension was released. This knowledge of tension could also have been used to our benefit during assembly. Assembling the system in a detentioned state and tensioning the system when all the components were in place, as opposed to assembling the system under tension, could have had the potential to ease the process Although we incorporated finite element analysis early in our design process, the deflection in our final physical assembly was much more than the analysis had indicated. More time could have been spent to calibrate the material within the FEA, specifying elements such as grain direction to have a better understanding of the structural capacity.
SCOPE The structural system proved to be successful in optimizing a delicate material to create structure. Moving forward, it would be interesting to experiment with the same system applied to taller structures. The global tensioning system was incorporated later in the design process. As a result, minimal testing of the system took place. Further experimentation of the system could include linking it to environmental sensors. This could facilitate global tensioning of the assembly when the system is under stress such as wind or other environmental conditions.
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Emergent Technologies and Design - Design and Technology