FEM tutorial
Tutorial |
Topic |
---|
{{{Topic}}} |
Level |
Beginner |
Time to complete |
10 minutes + Solver time |
Authors |
Drei |
FreeCAD version |
0.16 or above |
Example files |
See also |
None |
Introduction
! DO NOT TRANSLATE AT THE MOMENT ! This tutorial is meant to introduce the reader to the basic workflow of the FEM Module, as well as most of the tools that are available to perform a static analysis.
Requirements
- For working with FreeCADs FEM_Module it is STONGLY recommended to use version 0.16 or above.
- The use of FreeCADs FEM_Module requires the installation of some external software. Check FEM_Install for further install instructions.
- The reader has the basic knowledge to use the Part and PartDesign Workbenches
Procedure
Geometrical model
In this example a Cube is used as the study object, but models created in the Part or PartDesign Workbenches can be used instead.
- Create a new document
- Activate the Part Workbench
- Create a Cube by clicking on Create a cube solid.
- We have a geometrical model to work with.
Create an analysis and mesh the geometrical model
- Switch to the FEM Workbench
- Select the cube in tree view
- Click New mechanical analysis create an analysis.
- An analysis container and a solver object will be created.
Netgen
- If FreeCADs build in mesher Netgen is available you will be directed to the task panel of File:Fem FemMesh.svg Create FEM mesh. If you did not change the size of the cube (10, 10, 10) you can leave the settings and click ok.
- The mesh will be created.
- The properties of the FEM mesh can be seen in the property editor of FreeCAD.
GMSH
- If FreeCADs build in mesher Netgen is not available you will get a popup saying "The FEM module is build without Netgen support ... " The usage of GMSH_macro is recommended, and is used for this example.
- Activate the macro
- Select the object you wish to use, in this case our Cube
- Check the box Create Mechanical Analysis from mesh
- Click OK
You can also drag and drop a mesh to a Mechanical Analysis that does not have a mesh within the Tree View.
We have now meshed our object and are ready to add constraints and forces.
Constraints and Forces
- Hide the mesh from the Tree View.
- Show the original model
- Select Create FEM fixed constraint
- Select the bottom face of the Box and click OK
- Select Create FEM force constraint
- Select the top face of the Box and set the Area load value to 20 000
- Click OK
We now have established the restrictions and forces for our static study.
Final preparations
- Select File:Fem Material.svg Mechanical material... and choose Steel-generic as the material
- Click OK
Running the Solver
- Select File:Fem NewAnalysis.svg Start calculation from the menu
- Select Write Calculix Input File
- Select Run Calculix
- Click Close
Analyzing Results
- Select File:Fem Result.svg Show result
- Choose among the different Result types to view the results
- The slider at the bottom can be used to alter the mesh to view the deformation in a simplified manner
- To remove the results select File:Fem PurgeResults.png Purge results
We are now finished with the basic workflow for the FEM Module.