solidspy 1.0.11a0

A simple Finite Element program

SolidsPy: 2D-Finite Element Analysis with Python

This repo contains a simple finite element analysis code for 2D elasticity problems. The code uses as input simple-to-create text files defining a model in terms of nodal, element, material and load data.

Features

The code allows the user to find the displacement, strain and stress solution for an arbitrary two-dimensional domain discretized into finite elements and subjected to point loads. It has been created for academic purposes and it is part of the teaching material developed for the courses IC0602 Introduction to the Finite Element Methods and IC0285 Computational Modeling at Universidad EAFIT. The code is organized in independent modules for pre-processing, assembly and post-processing allowing the user to easily modify it or add features like new elements.

The repo contains 5 main folders:

1. solidspy/ which stores the source code in the following modules:

   • solids_GUI.py: The main program;
   • preprocesor.py: Pre-processing subroutines including Gmsh convertion functions using meshio
   • assemutil.py: Assembly of elemental stiffness matrices ;
   • femutil.py: Shape functions, its derivatives and general finite element method subroutines;
   • uelutil.py: Elemental or local matrix subroutines for different elements; and
   • postprocesor.py: Several results handling subroutines.

2. meshes/ Complete models including its Gmsh representation and a Python script to produce the required (nodes, elements, materials and load) text files ready for input.

3. docs/ Documentation files in the form of easy-to-follow tutorials showing how to define a SolidsPy model in terms of text files and model creation with Gmsh.

4. examples/ Specific applications using SolidsPy functions to conduct analysis.

5. tests/ Unit testing scripts.

Installation

The code is written in Python and it depends on numpy, scipy and sympy.

To install SolidsPy open a terminal and type:

pip install solidspy

To run the examples with specification of the folder stoing the input files through a GUI you will need to install easygui.

To easily generate the required SolidsPy text files out of a Gmsh model you will need meshio.

These two can be installed with:

pip install easygui
pip install meshio

How to run a simple model

After installation, you can run an analysis in 3 easy steps (see template):

• Create the model (i.e., geometry and mesh) using Gmsh. Several meshes are available in the repo SOLIDSPy-meshes
• Generate the text files (eles.txt, nodes.txt, mater.txt and loads.txt) required by SolidsPy using a python script based on meshio.
• Run it in Python as follows:

import matplotlib.pyplot as plt  # load matplotlib
from solidspy import solids_GUI  # import our package
disp = solids_GUI()  # run the Finite Element Analysis
plt.show()    # plot contours

This would not work properly in Anaconda for Mac OS. In that case is suggested to use an IPython console to run the example.

License

This project is licensed under the MIT license. The documents are licensed under

Creative Commons Attribution License.

Authors

• Juan Gomez, Professor at Universidad EAFIT.
• Nicolás Guarín-Zapata, Researcher at the Applied Mechanics Group at Universidad EAFIT.