A Python Structural Analysis Package for linear problems.
Clone or download from github directory to import StructPy. The StructPy package contains the following modules:
• Element.py : defines elemData class and its associated methods localize, elemLength
• Model.py : defines Model class and its associated method index_fr
• Kinematics.py : defines functions create_A_Matrix, create_ag_Matrix, create_Af_Matrix
• Load.py : defines functions create_P_vector, create_Pf_vector
• StiffnessMatrix.py : defines functions create_k_Matrix, create_Ks_Matrix, create_Kff_Matrix
• DispMethod.py : defines function solver that applies the displacement method of analysis
• plotter2D.py : defines functions window, undeformed2D, deformed2D, axial_Force2D
• plotter3D.py : (not yet implemented)
✓ 2-D Truss Analysis
3-D Truss Analysis
2-D Frame Analysis
3-D Frame Analysis
✓ 2-D Plotting
✓ Undeformed Shape
✓ Deformed Shape
✓ Axial Force
Shear Force
Bending Moment
3-D Plotting
Hinge modeling
Distributed Loading
Dynamic Loading
First begin by importing the necessary modules from StructPy:
from StructPy import Element, Model, DispMethod, plotter2D
import numpy as np
Define the model geometry, where XYZ contains nodal positions, CONN contains connectivity information and BOUND specifies boundary conditions (0 for free and 1 for fixed):
# Nodal Position & Nodal load definition
XYZ = np.array([[0,0,0],[1,2,0],[2,0,0]]).astype(np.float32)
nodal_load = {2:[100.,100.]}
# Connectivity
CONN = np.array([[1,2],[2,3],[1,3]])
# Boundary Condition
BOUND = np.array([[1,1,0],[0,0,0],[0,1,0]])
Create Elem object that contains material information on elements:
for i in range(n):
Elem.E[i] = 10000.
Elem.A[i] = 20.
Elem.I[i] = 1000.
Elem.TYPE[i] = 'TRUSS'
Create model object and use displacement method to solve for nodal displacements U and element internal forces Q:
# Create model
model = Model.CreateModel(Elem, XYZ, CONN, BOUND)
# Nodal displacement U, element force Q
U,Q = DispMethod.solver(model, Elem, nodal_load)
The undeformed and deformed shape, as well as axial forces can then be plotted:
undeformed = plotter2D.undeformed2D(model, nodal_load)
deformed = plotter2D.deformed2D(model,U, scale = 100)
axialForce = plotter2D.axial_Force2D(model, Q)
A more complicated model can be created by simply changing the geometry numpy arrays XYZ, CONN and BOUND. A simply supported Pratt truss is shown in this example:
# Nodal Position & Nodal load definition
XYZ = np.zeros([16,3])
for i in range(9):
XYZ[i] = [i*100, 0, 0]
for i in range(9,16):
XYZ[i] = [(i-8)*100, 100, 0]
nodal_load = {13:[0.,-100.]}
# Connectivity
CONN = np.zeros([29,2]).astype(np.int64)
for i in range(8):
CONN[i] = [i+1,i+2]
for i in range(23,29):
CONN[i] = [i-13, i-12]
CONN[8:23,:] = [[1,10],
[2,10],
[3,10],
[3,11],
[4,11],
[4,12],
[5,12],
[5,13],
[5,14],
[6,14],
[6,15],
[7,15],
[7,16],
[8,16],
[9,16]]
In this example, a 2-D arch structure measuring 180 ft in width and 60 ft in height is analyzed. Again change model geometry through XYZ, CONN and BOUND:
# Nodal Position & Nodal load definition
x1 = np.linspace(-90,90,19)
x2 = np.linspace(-80,80,19)
y1 = 60 - 0.00741 * np.square(x1)
y2 = 50 - 0.00781 * np.square(x2)
XYZ = np.zeros([38 , 3])
XYZ[0:19,0] = x1
XYZ[0:19,1] = y1
XYZ[19:,0] = x2
XYZ[19:,1] = y2
nodal_load = {10:[100.,0.], 29 :[100,0]}
# Connectivity
CONN = np.zeros([71,2]).astype(np.int64)
for i in range(18):
CONN[i] = [i+1, i+2]
for i in range(18,36):
CONN[i] = [i+2, i+3]
for i in range(36, 45):
CONN[i] = [i-34, i-16]
for i in range(45,54):
CONN[i] = [i-35, i-15]
for i in range(54,71):
CONN[i] = [i-52, i-33]
# Boundary Condition
BOUND = np.zeros([38,3]).astype(np.int64)
BOUND[0] = [1,1,0]
BOUND[19] = [1,1,0]
BOUND[20] = [1,1,0]
BOUND[37] = [1,1,0]
