anaStruct 2D Frames and Trusses
Analyse 2D Frames and trusses for slender structures. Determine the bending moments, shear forces, axial forces and displacements.
Installation
For the actively developed version:
$ pip install git+https://github.com/ritchie46/anaStruct.git
Or for a release:
$ pip install anastruct
Read the docs!
Questions
Got a question? Please ask on gitter.
Includes
- trusses ✔️
- beams ✔️
- moment lines ✔️
- axial force lines ✔️
- shear force lines ✔️
- displacement lines ✔️
- hinged supports ✔️
- fixed supports ✔️
- spring supports ✔️
- q-load in elements direction ✔️
- point loads in global x, y directions on nodes ✔️
- dead load ✔️
- q-loads in global y direction ✔️
- hinged elements ✔️
- rotational springs ✔️
- non-linear nodes ✔️
- geometrical non linearity ✔️
- load cases and load combinations ✔️
- generic type of section - rectangle and circle ✔️
- EU, US, UK steel section database ✔️
Examples
from anastruct import SystemElements
import numpy as np
ss = SystemElements()
element_type = 'truss'
# Create 2 towers
width = 6
span = 30
k = 5e3
# create triangles
y = np.arange(1, 10) * np.pi
x = np.cos(y) * width * 0.5
x -= x.min()
for length in [0, span]:
x_left_column = np.ones(y[::2].shape) * x.min() + length
x_right_column = np.ones(y[::2].shape[0] + 1) * x.max() + length
# add triangles
ss.add_element_grid(x + length, y, element_type=element_type)
# add vertical elements
ss.add_element_grid(x_left_column, y[::2], element_type=element_type)
ss.add_element_grid(x_right_column, np.r_[y[0], y[1::2], y[-1]], element_type=element_type)
ss.add_support_spring(
node_id=ss.find_node_id(vertex=[x_left_column[0], y[0]]),
translation=2,
k=k)
ss.add_support_spring(
node_id=ss.find_node_id(vertex=[x_right_column[0], y[0]]),
translation=2,
k=k)
# add top girder
ss.add_element_grid([0, width, span, span + width], np.ones(4) * y.max(), EI=10e3)
# Add stability elements at the bottom.
ss.add_truss_element([[0, y.min()], [width, y.min()]])
ss.add_truss_element([[span, y.min()], [span + width, y.min()]])
for el in ss.element_map.values():
# apply wind load on elements that are vertical
if np.isclose(np.sin(el.ai), 1):
ss.q_load(
q=1,
element_id=el.id,
direction='x'
)
ss.show_structure()
ss.solve()
ss.show_displacement(factor=2)
ss.show_bending_moment()
from anastruct import SystemElements
ss = SystemElements(EA=15000, EI=5000)
# Add beams to the system.
ss.add_element(location=[0, 5])
ss.add_element(location=[[0, 5], [5, 5]])
ss.add_element(location=[[5, 5], [5, 0]])
# Add a fixed support at node 1.
ss.add_support_fixed(node_id=1)
# Add a rotational spring support at node 4.
ss.add_support_spring(node_id=4, translation=3, k=4000)
# Add loads.
ss.point_load(Fx=30, node_id=2)
ss.q_load(q=-10, element_id=2)
# Solve
ss.solve()
# Get visual results.
ss.show_structure()
ss.show_reaction_force()
ss.show_axial_force()
ss.show_shear_force()
ss.show_bending_moment()
ss.show_displacement()