FEM tutorial/en

Introduction
This tutorial is meant to introduce the reader to the basic workflow of the FEM Workbench, as well as most of the tools that are available to perform a static analysis.



Requirements

 * FreeCAD version 0.16 or above
 * Netgen and/or GMSH is installed on the system
 * In the case of GMSH, installation of psicofil's macro is recommended
 * Calculix is installed on the system
 * The reader has the basic knowledge to use the Part and PartDesign Workbenches

Procedure
The following steps show in detail how to perform a Finite Element Analysis (FEA) on a basic cube.

Modeling
In this example a Cube is used as the study object, but models created in the Part or PartDesign Workbenches can used instead.


 * 1) Create a new document
 * 2) Activate the Part Workbench
 * 3) Create a Cube

Now we have a model with which to work with.

Meshing the model

 * 1) Switch to the FEM Workbench

Netgen

 * 1) Select the model
 * 2) Select [[Image:Fem_FemMesh.svg|32px]] Create FEM mesh
 * 3) Click Ok
 * 4) Select the Mesh from the Tree View
 * 5) Click [[Image:Fem_Analysis.svg|32px]] New mechanical analysis from the menu to create an analysis from the mesh that was created.

You can also drag and drop a mesh to a Mechanical Analysis that does not have a mesh within the Tree View.

GMSH
The usage of psicofil's macro is recommended, and is used for this example.
 * 1) Activate the macro
 * 2) Select the object you wish to use, in this case our Cube
 * 3) Check the box Create Mechanical Analysis from mesh
 * 4) Click OK

We have now meshed our object and are ready to add constraints and forces.

Constraints and Forces

 * 1) Hide the mesh from the Tree View.
 * 2) Show the original model
 * 3) Select [[Image:Fem_ConstraintFixed.svg|32px]] Create FEM fixed constraint
 * 4) Select the bottom face of the Box and click OK
 * 5) Select  [[Image:Fem_ConstraintForce.svg|32px]] Create FEM force constraint
 * 6) Select the top face of the Box and set the Area load  value to 20 000
 * 7) Click OK

We now have established the restrictions and forces for our static study.

Final preparations

 * 1) Select [[Image:Fem_Material.svg|32px]] Mechanical material... and choose Steel-generic as the material
 * 2) Click OK

Running the Solver

 * 1) Select  [[Image:Fem_NewAnalysis.svg|32px]] Start calculation from the menu
 * 2) Select Write Calculix Input File
 * 3) Select Run Calculix
 * 4) Click Close

Analyzing Results

 * 1) Select [[Image:Fem_Result.svg|32px]] Show result
 * 2) Choose among the different Result types to view the results
 * 3) The slider at the bottom can be used to alter the mesh to view the deformation in a simplified manner
 * 4) To remove the results select [[Image:Fem_PurgeResults.png|32px]] Purge results