anastruct 1.6.1

Finite element analysis of 2D structures

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!

Documentation

Questions

Got a question? Please ask on gitter.

Includes

• trusses :heavy_check_mark:
• beams :heavy_check_mark:
• moment lines :heavy_check_mark:
• axial force lines :heavy_check_mark:
• shear force lines :heavy_check_mark:
• displacement lines :heavy_check_mark:
• hinged supports :heavy_check_mark:
• fixed supports :heavy_check_mark:
• spring supports :heavy_check_mark:
• q-load in elements direction :heavy_check_mark:
• point loads in global x, y directions on nodes :heavy_check_mark:
• dead load :heavy_check_mark:
• q-loads in global y direction :heavy_check_mark:
• hinged elements :heavy_check_mark:
• rotational springs :heavy_check_mark:
• non-linear nodes :heavy_check_mark:
• geometrical non linearity :heavy_check_mark:
• load cases and load combinations :heavy_check_mark:
• generic type of section - rectangle and circle :heavy_check_mark:
• EU, US, UK steel section database :heavy_check_mark:

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()

Real world use case.

Non linear water accumulation analysis