FEM tutorial/en: Difference between revisions

Revision as of 20:50, 5 September 2015

Topic
Tutorial
{{{Topic}}}
Level

Time to complete

Authors

FreeCAD version
0.16
Example files

See also
None

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.

Create a new document
Activate the Part Workbench
Create a Cube

Now we have a model with which to work with.

Meshing the model

Switch to the FEM Workbench

Netgen

Select the model
Select File:Fem FemMesh.svg Create FEM mesh
Click Ok
Select the Mesh from the Tree View
Click 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.

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

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

Other languages:

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+=== 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.
+[[Image:FEM_tutorial_result.png|480px]]
+=== Requirements ===
+* FreeCAD version 0.16 or above
+* [http://sourceforge.net/projects/netgen-mesher/ Netgen] and/or [http://geuz.org/gmsh/ GMSH] is installed on the system
+* In the case of GMSH, installation of  [https://github.com/psicofil/Macros_FreeCAD psicofil's macro] is recommended
+* [http://www.calculix.de/ 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.
-==== Select Part Workbench ====
+==== Modeling ====
+In this example a Cube is used as the study object, but models created in the Part or PartDesign Workbenches can used instead.
+# Create a new document
+# Activate the Part Workbench
+# Create a Cube
+Now we have a model with which to work with.
+==== Meshing the model ====
+# Switch to the FEM Workbench
+===== Netgen =====
+# Select the model
+# Select [[Image:Fem_FemMesh.svg|32px]] [[FEM Create|Create FEM mesh]]
+# Click '''Ok'''
+# Select the Mesh from the Tree View
+# Click [[Image:Fem_Analysis.svg|32px]] [[FEM Analysis|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 =====
-[[File:FEM_Analysis_(1).png|500px]]
+The usage of psicofil's 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'''
+We have now meshed our object and are ready to add constraints and forces.
-==== Create a Cube ====
+==== Constraints and Forces ====
-[[File:FEM Analysis(2).png|500px]]
+# Hide the mesh from the Tree View.
+# Show the original model
+# Select [[Image:Fem_ConstraintFixed.svg|32px]] [[FEM FixedConstraint|Create FEM fixed constraint]]
+# Select the bottom face of the Box and click OK
+# Select  [[Image:Fem_ConstraintForce.svg|32px]] [[FEM ForceConstraint|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.
-==== Highlight the Cube in the selection tree and select the data tab to check the dimensions ====
+==== Final preparations ====
-[[File:FEM Analysis(3).png|500px]]
+# Select [[Image:Fem_Material.svg|32px]] [[FEM Material|Mechanical material...]] and choose Steel-generic as the material
+# Click '''OK'''
-==== Switch to the FEM Workbench ====
+====  Running the Solver ====
+# Select  [[Image:Fem_NewAnalysis.svg|32px]] [[FEM Calculation|Start calculation]] from the menu
+# Select '''Write Calculix Input File'''
+# Select '''Run Calculix'''
+# Click '''Close'''
+==== Analyzing Results ====
-[[File:FEM Analysis(4).png|500px]]
+# Select [[Image:Fem_Result.svg|32px]] [[FEM ShowResult|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 [[Image:Fem_PurgeResults.png|32px]] [[FEM PurgeResults|Purge results]]
 [[Category:User Documentation]]