This repository is designed for learning about CalculiX (an open-source Finite Element Analysis solver) and using Python to automate and enhance post-processing. accessible and programmable.

The goal is to build a set of tools to read, analyze, and visualize FEA results directly in Python, allowing for custom workflows beyond standard GUI pre/post-processors.

This project uses uv for dependency and Python version management.

1. Install uv Follow the instructions at docs.astral.sh/uv.

2. Setup Python Install Python 3.12.2 and create the virtual environment using this version:

   uv python install 3.12.2
   uv venv --python 3.12.2

3. Install Dependencies Install the project dependencies into the virtual environment:

   uv sync

To launch a Jupyter Notebook environment with access to the project's dependencies:

uv run --with jupyter jupyter notebook

You can run the provided example scripts directly:

uv run src/example.py

To run the project's test suite:

uv run pytest .\tests\

• examples/1_simple_plate_static: A basic static analysis of a shell element plate. Includes the .inp file for CalculiX and Python scripts to visualize the results (Von Mises stress, etc.).

The Python codebase (src/) provides the following functionality:

• Model Reading (model/):

  • Parse CalculiX Input files (.inp).
  • Extract Nodes, Elements (Shell 4-node, Truss 2-node, Tetrahedral 10-node), and Shell Thicknesses.
  • Parse Materials (*MATERIAL, *ELASTIC, *DENSITY) and Solid Sections (*SOLID SECTION).
  • Utility to find nodes along lines/coordinates.

• Result Reading (results/):

  • Parse CalculiX Result files (.frd).
  • Extract multiple Steps, Time/Increments, and nodal data (Displacement, Stress, Force, Strain, etc.).
  • Truss Force Calculator: Compute axial forces in truss members based on displacements and element properties.
  • Utilities to map node results to coordinates for plotting (get_nodes_results).
  • Result comparison logic (e.g., ratio of Von Mises stress between two analyses).

• Visualization (plotting/):

  • matplotlib-based plotting engine.
  • Plot mesh geometry (Shells as patches, Trusses as lines).
  • Visualize field variables (Stress, Displacement) as heatmaps (Shells).
  • Deformed Shape Plotting: Visualize truss deformation with scaled displacement.
  • Compare results between two models with ratio plotting.
  • Configurable plotting (custom ranges, highlighting neutral values, etc.).