FEM Workbench

    From FreeCAD Documentation
    (Redirected from FEM Module)
    FEM workbench icon


    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).



    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.

    FEM Workbench workflow.svg

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

    Menu: Model

    • FEM Analysis.svg 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.


    Element Geometry

    Electromagnetic Constraints

    Fluid Constraints

    Geometrical Constraints

    Mechanical Constraints

    • FEM ConstraintTie.svg Constraint tie: Used to define a tie constraint ("bonded contact") between two faces.
    • FEM ConstraintForce.svg Constraint force: Used to define a force in [N] applied uniformly to a selectable face in a definable direction.

    Thermal Constraints

    Constraints without solver

    Overwrite Constants

    Menu: Mesh

    • FEM MeshRegion.svg FEM mesh region: Creates a localized area(s) to mesh which highly optimizes analysis time.
    • FEM MeshGroup.svg FEM mesh group: Groups and labels elements of a mesh (vertex, edge, surface) together, useful for exporting the mesh to external solvers.
    • FEM CreateNodesSet.svg Nodes set: Creates/defines a node set from FEM mesh.

    Menu: Solve

    • FEM SolverZ88.svg Solver Z88: Creates the solver controller for Z88.

    Menu: Results

    • FEM PostPipelineFromResult.svg Post pipeline from result: Used to add a new graphical representation of FEM analysis results (color scale and more display options).
    • FEM PostFilterWarp.svg Warp filter: Used to visualize the scaled deformed shape of the model.
    • FEM PostFilterCutFunction.svg Function cut filter: Used to display the results on a sphere or a plane cutting through the model.
    • FEM PostFilterClipRegion.svg Region clip filter: Used to clip a field with a sphere or a plane cutting through the model.
    • FEM CompPostCreateFunctions.png Filter functions: This is an icon menu in the FEM Results toolbar that holds the following commands:

    Menu: Utilities

    Context Menu

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



    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.


    Tutorial 1: FEM CalculiX Cantilever 3D; basic simply supported beam analysis.

    Tutorial 2: FEM Tutorial; simple tension analysis of a structure.

    Tutorial 3: FEM Tutorial Python; set up the cantilever example entirely through scripting in Python, including the mesh.

    Tutorial 4: FEM Shear of a Composite Block; see the deformation of a block that is comprised of two materials.

    Tutorial 5: Transient FEM analysis

    Tutorial 6: Post-Processing of FEM Results with Paraview

    Tutorial 7: FEM Example Capacitance Two Balls; Elmer's GUI tutorial 6 "Electrostatics Capacitance Two Balls" using FEM Examples.

    Coupled thermal mechanical analysis tutorials by openSIM

    Video tutorial 1: FEM video for beginner (including YouTube link)

    Video tutorial 2: FEM video for beginner (including YouTube link)

    Many video tutorials: anisim Open Source Engineering Software (in German)

    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