Ruili Wang, Dayu Long, Chenglu Xue | Experiment in Structure

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