Tensioning method for tensegrity keel

Patent metadata

Field	Value
Publication number	US-2023234721-A1
Application number	US-202318191089-A
Country	US
Kind code	A1
Filing date	Mar 28, 2023
Priority date	Sep 30, 2020
Publication date	Jul 27, 2023
Grant date	—

Abstract

A tensioning method for a tensegrity keel includes the steps of: (Step 1) determining target values at an attainment of tensegrity; (Step 2) forming an outline of the integral keel; (Step 3) secondarily tensioning a middle stiffening ring through stretching a hub shaft, thereby attaining a self-equilibrium state; (Step 4) providing telescopic rods between stiffening rings and central trusses so that the stiffening rings and the central trusses are connected together; (Step 5) mounting longitudinal ties; (Step 6) releasing constraints on bisection points and the central trusses and tensioning the integral keel by stretching the telescopic rods, thereby introducing tension to the longitudinal ties; (Step 7) secondarily tensioning lateral stiffening rings by stretching the hub shaft, thereby attaining a self-equilibrium state; and (Step 8) making adjustments using iterative methods so that target values at the attainment of tensegrity will be reached.

First claim

1 . A tensioning method for a tensegrity keel, comprising the steps of:
step 1: determining target values at an attainment of tensegrity, the target values including target tensile force value for longitudinal ties, first final coordinates for bisection points, a second final coordinate for a first end and a third final coordinate for a second end at the attainment of tensegrity; step 2: successively placing a plurality of stiffening rings and a plurality of central trusses to form an outline of the keel and fixing bisection points of the individual stiffening rings; step 3: secondarily tensioning a first stiffening ring, thereby attaining a self-equilibrium state; step 4: providing telescopic rods between the stiffening rings and the central trusses so that the stiffening rings and the central trusses are connected together; step 5: mounting the longitudinal ties; step 6 releasing constraints on the bisection points and the central trusses and tensioning the keel, thereby introducing tension to the longitudinal ties so that tensile forces on the longitudinal ties at the attainment of tensegrity will reach the target tensile force value; step 7: secondarily tensioning the other stiffening rings than the first stiffening ring, thereby attaining a self-equilibrium state; and step 8: adjusting initial position coordinates of the bisection points, the first end and the second end so that the bisection points will reach the first final coordinates, the first end will reach the second final coordinate and the second end will reach the third final coordinate, at the attainment of tensegrity.

2 . The tension method of claim 1 , wherein in the step 3, the first stiffening ring is secondarily tensioned by stretching a hub shaft.

3 . The tension method of claim 2 , wherein in the step 5, the longitudinal ties are mounted by attachment following stretching or compression of them.

4 . The tension method of claim 3 , wherein in the step 5, the longitudinal ties are successively mounted in order from a middle to both ends.

5 . The tension method of claim 4 , wherein in the step 5, the longitudinal ties are mounted in symmetry.

6 . The tension method of claim 5 , wherein in the step 5, an initial length of the longitudinal ties when they are not under stress is adjusted using a first iterative method so that the stiffening rings will not skew when a final shape is formed by tensioning.

7 . The tension method of claim 6 , wherein the first iterative method comprises: determining coordinates of first chords in the stiffening rings; determining coordinates of second chords in the stiffening rings; determining average position coordinates of the first chords and the second chords; and adjusting a length of the longitudinal ties when they are not under stress so that differences between the average position coordinates and the first final coordinates are less than a predetermined value, and then stopping iteration.

8 . The tension method of claim 7 , wherein in the step 6, the keel is tensioned by stretching the telescopic rods.

9 . The tension method of claim 8 , wherein in the step 6, the telescopic rods are stretched by raising a temperature.

10 . The tension method of claim 9 , wherein in the step 6, a temperature load on the telescopic rods is adjusted using a second iterative method.

11 . The tension method of claim 10 , wherein the second iterative method comprises: determining tensile forces on the longitudinal ties; adjusting the temperature load on the telescopic rods so that differences between the tensile forces on the longitudinal ties and the target tensile force value are less than a predetermined value, and then stopping iteration.

12 . The tension method of claim 11 , wherein in the step 8, initial position coordinates of the bisection points, the first end and the second end are adjusted using a third iterative method.

13 . The tension method of claim 12 , wherein the third iterative method comprises: determining position coordinates of the bisection points at the attainment of tensegrity; and adjusting the initial position coordinates of the bisection points so that differences between the position coordinates of the bisection points at the attainment of tensegrity and the first final coordinates are less than a predetermined value.

14 . The tension method of claim 13 , wherein the third iterative method comprises: determining a position coordinate of the first end at the attainment of tensegrity; and adjusting the initial position coordinate of the first end so that a difference between the position coordinate of the first end at the attainment of tensegrity and the second final coordinate is less than a predetermined value.

15 . The tension method of claim 14 , wherein the third iterative method comprises: determining a position coordinate of the second end at the attainment of tensegrity; and adjusting the initial position coordinate of the second end so that a difference between the position coordinate of the second end at the attainment of tensegrity and the third final coordinate is less than a predetermined value.

16 . The tension method of claim 15 , wherein the longitudinal ties are tension members, which are linearly elastic when tensioned.

17 . The tension method of claim 16 , wherein the longitudinal ties are made of carbon fibers.

18 . The tension method of claim 17 , wherein the central trusses are thin-walled tubular compression members.

19 . The tension method of claim 18 , wherein the central trusses are linearly elastic when compressed.

20 . The tension method of claim 18 , wherein the central trusses are made of carbon fibers.

Assignees

• Univ Shanghai Jiaotong
• New United Group Co Ltd

Inventors

• Chen Wujun
• Zhang Yibei
• Gao Chengjun
• Hu Jianhui
• Xu Jiandong
• Liu Jing
• Xiang Haijun

Classifications

• B64B1/08 Primary

  Framework construction · CPC title

• B64F5/10

  Manufacturing or assembling aircraft, e.g. jigs therefor · CPC title

• B64F5/00 Primary

  Designing, manufacturing, assembling, cleaning, maintaining or repairing aircraft, not otherwise provided for; Handling, transporting, testing or inspecting aircraft components, not otherwise provided for · CPC title

• G06F30/15 Primary

  Vehicle, aircraft or watercraft design · CPC title

• G06F30/20

  Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) · CPC title