FEM FrontISTR Workbench

Introduction

The FEM FrontISTR Workbench is a FreeCAD addon that enables FrontISTR, an open-source large-scale parallel FEM program for nonlinear structural analysis.

Intended work-flow

1. Set up an analysis model by FEM module (in the same way as CalculiX).
2. Switch to the workbench FrontISTR and create a FrontISTR solver object by clicking on the toolbar button .
3. Double-click on the solver object in the document tree and set the working directory.
4. Click on the button Write input file
5. Click on the button Run FrontISTR
6. Check FISTR_Results for post-processing.

Features

• static analysis, element check
• geometrical linear|nonlinear analysis
• elements: 1st/2nd order tetrahedron
• loads: mechanical concentrated and distributed loads, gravity
• boundary: points fixed or displacement
• step control: auto time increment and cutback
• linear equation solver
  • iterative
    • preconditioner: AMG, SSOR, Diagonal, ILU(k)(k=0,1,2)
    • method: CG, BiCGSTAB, GMRES, GPBiCG
  • direct: MUMPS
• output file format: AVS, VTK (ParaView required)

Features to be supported in the future

• analysis: thermal transfer, dynamic, eigenfrequency
• materials(mechanical): elastoplastic, hyperelastic, creep, viscoelastic
• contact
• MPC(TIE)
• elements: prism, hexa, beam, shell, truss, etc.

Limitations

• FISTR_Results only contains results for surfaces. If you need the interior results, change the Output File Format to VTK and visualize the results with ParaView.
• The FEM FrontISTR workbench does not yet support thermal analyses. FISTR itself can perform thermal analyses and support for this is planned in the near future.
• Mechanical analyses with different materials in the model are not yet possible.

Benchmark results

See https://github.com/FrontISTR/FEM_FrontISTR/tree/master/sample/benchmarks.

Installation

Addon Manager

FEM_FrontISTR can easily be installed via the FreeCAD Addon Manager from the Tools → Addon manager menu. FEM_FrontISTR is under active development and will get new features frequently. Therefore you should update it regularly using the menu Tools → Addon manager. The FEM_FrontISTR code is hosted and developed on GitHub.

Manual

See How to install additional workbenches.

Prerequisites

• FreeCAD 0.19 or newer
• ParaView (optional)

FrontISTR Solver Installation

FrontISTR binaries will be automatically downloaded and installed on the first run. If the download does not proceed, please follow the steps below to install the solver.

Windows

1. Download FrontISTR-latest.zip
2. Create directory FEM_FrontISTR/bin
3. Extract FrontISTR-latest.zip and put all files in FEM_FrontISTR/bin directory.

Linux

Under preparation.

Mac

Under preparation.

Tools

• Solver FrontISTR Standard: Creates a new FrontISTR solver for this analysis.

References

• Author: kinagaki rigarashi
• Source code: Github.com
• FreeCAD Forum: 58019
• Tutorials: https://frontistr-commons.gitlab.io/FEM_FrontISTR/en/
• FrontISTR solver documentation: https://manual.frontistr.com/en/
• Report bugs: Please report bugs at Github.com