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FEM Workbench

Introduction

The FEM Workbench provides a modern finite element analysis (FEA) workflow for FreeCAD. Mainly this means all tools to make an analysis are combined into one graphical user interface (GUI).

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FEM workbench icon

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Workflow

The steps to carry out a finite element analysis are:

  1. Preprocessing: setting up the analysis problem.
    1. Modeling the geometry: creating the geometry with FreeCAD, or importing it from a different application.
    2. Creating an analysis.
      1. Adding simulation constraints such as loads and fixed supports to the geometric model.
      2. Adding materials to the parts of the geometric model.
      3. Creating a finite element mesh for the geometrical model, or importing it from a different application.
  2. Solving: running an external solver from within FreeCAD.
  3. Postprocessing: visualizing the analysis results from within FreeCAD, or exporting the results so they can be postprocessed with another application.

The FEM Workbench can be used on Linux, Windows, and Mac OSX. Since the workbench makes use of external solvers, the amount of manual setup will depend on the operating system that you are using. See FEM Install for instructions on setting up the external tools.

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Workflow of the FEM Workbench; the workbench calls two external programs to perform the meshing of a solid object, and the actual solution of the finite element problem.

  • image Analysis container: Creates a new container for a mechanical analysis. If a solid is selected in the tree view before clicking on it, the meshing dialog will be opened next.

Materials

Element Geometry

Electromagnetic Constraints

Fluid Constraints

Geometrical Constraints

Mechanical Constraints

Thermal Constraints

Constraints without solver

Overwrite Constants

Context Menu

  • image Clear FEM mesh: Deletes the mesh file from the FreeCAD file. Useful to make a FreeCAD file lighter.
  • image Display FEM mesh info: Displays basic statistics of existing mesh - number of nodes and elements of each type.

Preferences

Information

The following pages explain different topics of the FEM Workbench.

  • FEM Install: a detailed description on how to set up the external programs used in the workbench.
  • FEM Mesh: further information on obtaining a mesh for finite element analysis.
  • FEM Solver: further information on the different solvers available in the workbench, and those that could be used in the future.
  • FEM CalculiX: further information on CalculiX, the default solver used in the workbench for structural analysis.
  • FEM Concrete: interesting information on the topic of simulating concrete structures.

Tutorials

Extending the FEM Workbench

The FEM Workbench is under constant development. An objective of the project is to find ways to easily interact with various FEM solvers, so that the end user can streamline the process of creating, meshing, simulating, and optimizing an engineering design problem, all within FreeCAD.

The following information is aimed at power users and developers who want to extend the FEM Workbench in different ways. Familiarity with C++ and Python is expected, and also some knowledge of the "document object" system used in FreeCAD is necessary; this information is available in the Power users hub and the Developer hub. Please notice that since FreeCAD is under active development, some articles may be too old, and thus obsolete. The most up to date information is discussed in the FreeCAD forums, in the Development section. For FEM discussions, advice or assistance in extending the workbench, the reader should refer to the FEM subforum.

The following articles explain how the workbench can be extended, for example, by adding new types of boundary conditions (constraints), or equations.

A developer's guide has been written to help power users in understanding the complex FreeCAD codebase and the interactions between the core elements and the individual workbenches. The book is hosted at github so multiple users can contribute to it and keep it updated.

Extending the FEM Workbench documentation

More information regarding extending or missing FEM documentation can be found in the forum: FEM documentation missing on the Wiki