Experiments in Structures Works | 2021.9 — 2021.12 Instructor | Mohamad Alkhayer
Ruili Wang Dayu Long Chenglu Xue
CONTENTS
01
Fink Truss Bridge
01
02
Tension Rods
07
03
Weaving
09
04
Single-layered Tensegrity
13
05
Double-layered Tensegrity
17
06
Folding
21
07
Final Project: Tensegrity Structure
23
Fink Truss Bridge Case Study
Structure Analysis —— Digital Model
A
B
Design Points
Two design points of the bridge structure
Fink Truss Bridge (Hamden, 1857) (1)
Truss Layer 1
Diagonal ties are divided into three groups, a group of diagonal tensioning to stabilize the frame structure.
This is/was the oldest metal bridge in the USA. It is said that Hunterdon County kept all the parts in a warehouse, waiting for someday when the end post can be recast for an affordable price. The Hamden Road Fink truss was an all iron bridge.
The second group of v-ties to stabilize the four groups of square frame, the third group to play a stable bridge structure stability.
Details (2)
Truss Layer 2
In the node design, we take into account as a physical model need to take into account the rationality. It is important to consider how the nodes link the bars, how the screws on the nodes are fixed, the screws on the form of tension locks with the nodes fixed.
The nodes of the Fink Truss bridge are complex and require multiple nodes to be connected from multiple directions. Therefore, it is necessary to focus on the design of nodes
Truss Layer 3 01
02
Node Refinement Design —— Digital Model
Set-up Process —— Physical Model
Laser-cut panels and wood round sticks together form a rod structural system.
A
A connector is added outside the node as decoration. B
03
04
Set-up Process —— Physical Model
Physical Model
The model builds a unique light and shadow effect.
05
06
Tension Rods Tension Prototype
Physical Model
In this Rod structure, we would like to try the action mode of tensioning structure. Our idea is to form a relatively stable triangular structure through wires and tubes, and then connect the base to the main tube through iron wires.
Axonmetric —— Digital Model
Finally, they are all connected together and the whole structure is tensed by adjusting the wire regulator.
Elevation
07
08
Weaving Axonmetric —— Digital Model
Elevation
Elevation_1
Plan Generation Elevation_2 Weaving takes the form of a 12-sided weave with six guitar tighteners and six holes on each side of the wood. As a result, the 12 variant energy best corresponds to this configuration. We used Grasshopper for parametric experiments, and finally determined the weaving with 12 edges as the main body.
09
10
Elevation_3
Plan Generation —— Grasshopper
Physical Model
11
12
Single-layered Tensegrity
Axonmetric_1
Prototype The single-layered tensegrity is made of octagons as the outer frame, through the wood frame to achieve, the middle of a number of octagons link automatically formed squares to form the whole plane. The nodes are nested using bolts and 3D-printed nodes that act as tightenable keys for the line and frame links.
Axonmetric_2
Layers
Axonmetric_3 Plan
Perspective
13
14
Physical Model
15
16
Double-layered Tensegrity Space Filling Polyhedra
Linear Analog —— Digital Model
The prototype of space geometry selected in this scheme is Truncated Octahedron. Duplicate it many times and place it in the hexagon frame. By simplifying Truncated Octahedron and extracting its border line, the border is connected with the external hexagonal border by iron wire. Meanwhile, spatial processing is made to make the structure between them more stable.
Generation Process
Plan
Prototype: Truncated Octahedron
Put in the hexagon border
Overlaying
17
Rationalization
Perspective
18
Digital Model
Physical Model
Elevation
Axonmetric_1
Axonmetric_2 19
20
Folding Physical Model Folding Pattern The folding pattern is acquired through a series of experiments. In order to fold, it is necessary to leave a space in the concave parts of the front and the back sides; otherwise, it is necessary to foldin the convex parts.
Experiments
21
22
Final Project: Tensegrity Structure Concept Generation
Basic Form
Plan 1
Plan 2
Orthogonal Axon
Hexagon Axon
The artwork "Snelson's X" is designed by Fuller. Fuller gave the structure a name, combining "tensegrity" with "tensional" and "integrity." This example shows that the force is accomplished through four nodes. The top view above shows that different individuals can form tensioning forces through four nodes.
“Snelson's X”
Based on the orthogonal form of the tensegrity model, a hexagon form is create. Two different-scaled hexagons act as a group. Two groups are then connected together.
The model from Design Optimization: combining Evolutionary Algorithms and Tensegrity shows how the rope holding two structures with the combination of tensions and compressions.
23
Tension Diagram
Connection Pattern 24
Superposition Step —— Digital Model
Tensegrity Core
Tensegrity Outskins
Weaving Layers
Hexagon acts as the main element of the project. Tensegrity core is developed from the basic form. The supporting cables are connected by hexagonal nodes spaced apart.
The outskin applied the same tensegrity as the core. Meanwhile, two hexagon frames on the top and bottom of the model is prepared for the next step of weaving.
Weaving step is based on the top and bottom hexagon frames. It confroms to the form of core cables` connection way.
1
2
25
3
26
Superposition Step —— Physical Model
Node Details —— Digital Model
Outskins Node 1
Single Hexagon Structure
Tensegrity Core
The outer nodes need to be inserted with two sticks and a small hole for the connection.
Outskins Node 2 This node needs to be connected to sticks and lines from four directions. It bears force from two directions, and acts as connection of two directions, so the node applies buckle strategy.
Single Outskins Structure
27
Tensegrity Outskins
Hexagon Node The hexagon nodes are connected in a horizontal pattern, connecting the sticks on both sides.
Outskins Node 3 The node is connected to four sticks, which conform to the Angle of the hexagon and have a certain tilt to adapt to the direction of the force.
The node design mainly considers the force direction of the rod and the connection mode of the line. Due to the particularity of space hexagon, the Angle needs to be adjusted accurately. Because of the weaving strategy and the weaving system is cross-connected, the links between the weaving systems should not collide. 28
Physical Model
30