TensegrityPy is a project collecting functions related to tensegrity structures for scientific research.
This is an ongoing project.
A tensegrity is created by providing three parameters: nodal coordinates, connectivity and member types. Nodal coordinates and connectivity are Numpy arrays, while member types is a list of enum tensegrity.Member.
The coordinates of each node form a row vector. For a 3D structure, the 1st column of the nodal coordinate matrix corresponds to x coordinate, the 2nd and 3rd correpond to y and z coordinates, respectively.
Connectivity is a matrix with dimension b by 2, where b is the number of members. Each row specifies which nodes the corresponding member connects. The node number counts from 1. For example, if Member 3 connects Node 1 and Node 2, then the 3rd row (index 2) should be [1, 2]. One should put the node number with smaller value at the first column.
Member types are specified with an enum whose members are CABLE and BAR.
import numpy as np
import tensegrity
config = {'nodal_coordinates': np.array([[0.2588, 0.9659, 0.5], # Node 1
[-0.9659, -0.2588, 0.5], # Node 2
[0.7071, -0.7071, 0.5], # Node 3
[0.2588, -0.9659, -0.5], # Node 4
[0.7071, 0.7071, -0.5], # Node 5
[-0.9659, 0.2588, -0.5]]), # Node 6
'connectivity': np.array([[1, 2],
[2, 3],
[1, 3],
[4, 5],
[5, 6],
[4, 6],
[1, 5],
[2, 6],
[3, 4],
[1, 4],
[2, 5],
[3, 6]]),
'member_types': [tensegrity.Member.CABLE, tensegrity.Member.CABLE, tensegrity.Member.CABLE, tensegrity.Member.CABLE,
tensegrity.Member.CABLE, tensegrity.Member.CABLE, tensegrity.Member.CABLE, tensegrity.Member.CABLE,
tensegrity.Member.CABLE, tensegrity.Member.BAR, tensegrity.Member.BAR, tensegrity.Member.BAR]}
structure = tensegrity.Tensegrity(**config)