FEM Install/fr

Introduction
Pour pouvoir effectuer une analyse par éléments finis (FEA) dans atelier FEM, FreeCAD utilise deux programmes externes: l’un est utilisé pour générer le FEM Mesh, l’autre pour la résolution numérique du analyse réelle. Vous pouvez tester si votre installation FreeCAD est prête pour FEA en exécutant l’exemple FEM CalculiX Cantilever 3D fourni avec l'installation de FreeCAD depuis la v0.17.



FEM Solver
Le solveur par défaut pour effectuer des calculs par éléments finis est CalculiX, un solveur simple pour l'analyse de structures. FreeCAD écrit un fichier d'entrée CalculiX, lance le solveur et lit le résultat qui peut ensuite être présenté visuellement dans la fenêtre d'affichage. Cela signifie que le binaire CalculiX est autonome et indépendant de FreeCAD. Etant donné que de nombreux programmes peuvent générer un maillage, il est recommandé d’installer le solveur et de s’assurer qu’il fonctionne en premier.

Si le solveur est correctement installé, vous pouvez exécuter la commande unique dans le terminal pour obtenir une réponse simple:

Si le solveur est installé, assurez-vous que l'atelier FEM est capable de trouver le binaire. Allez à. Si vous avez compilé le solveur vous-même, décochez l'option et donnez le chemin correct au fichier binaire. Pour les autres solveurs pouvant être utilisés avec FreeCAD, voir FEM Solveur.

Générateur de maillage FEM
Afin de créer un FEM Mesh, FreeCAD utilise Gmsh comme mailleur par défaut. Pour que cela fonctionne, Gmsh doit être installé séparément de FreeCAD.

Si le programme est correctement installé, vous pouvez exécuter la commande dans le terminal pour lancer l'interface graphique du programme. Cette interface n’est pas utilisée par FreeCAD mais montre que le programme est installé.

If the mesher is installed, make sure the FEM Workbench is able to find the binary; go to. If you compiled the mesher yourself, untick the option, and give the correct path to the binary. See FEM Mesh for various possibilities of obtaining a valid mesh for analysis.

Netgen
In previous versions of FreeCAD, Netgen was the default mesher. For it to work with the FEM Workbench, FreeCAD had to be linked against the Netgen libraries at compile time. As FreeCAD transitioned from OCE 0.17 to OCCT 7.1, Netgen 4.9.13 failed to link against this version of OCCT, so it was decided to drop Netgen support in the FEM Workbench (the Netgen button was removed). Nevertheless, shortly afterwards some users reported success in patching Netgen 5.3.1, so that it worked with OCCT 7.x and FreeCAD.

For historical reference, see the threads:
 * (Ubuntu Daily PPA) Transitioning to OCCT7, VTK7...
 * Ubuntu Daily Builds PPA now using OCC 7.1.0
 * patching Netgen 5.3.1 to work with OCCT 7.1
 * Troubles with gmsh in FEM wb (netgen nostalgy)

Despite Netgen not being available from within the FEM Workbench, it can still be used by itself to produce meshes that can then be imported.

If the program is correctly installed, you may run the command in the terminal to launch the graphical interface of the program.

Installing on Windows
The FreeCAD packages available from the download page already include Netgen and CalculiX, so no additional software needs to be installed.

Installing on Linux
Linux distributions have different ways of installing software. Many distributions have software repositories and package managers; before compiling source code, look in your package manager for, , or , and install them following the instructions of your own distribution.

Ubuntu PPA
The freecad-stable and freecad-daily personal package archives (PPA) provide a more recent version of FreeCAD than is available in the official Ubuntu repositories. These PPAs include the most recent, , and packages as well. See Install on Unix for more information on setting up the repositories.

If a PPA is already added to your system, install the packages as follows

The freecad-community PPA also provides, , and packages for testing. If they are stable enough, they may be added to the daily or stable repositories.

the thread Ubuntu Repository discusses the creation of the Ubuntu PPA packages. At the time it was written, CalculiX was not included in the Debian repositories, so there were several personal packages in Launchpad. Only one package should be installed.

Arch Linux
Get the CalculiX package from the AUR repository.

Debian

 * Debian 9 Buster: the packages in the repository are outdated, but you can use the packages from the Ubuntu PPA . See Gmsh 4 package available for testing in Community Extras PPA (forum post).
 * Debian 8 Stretch: the packages in the repository are outdated, but you can use the packages from the Ubuntu PPA . See Gmsh 4 package available for testing in Community Extras PPA (forum post).
 * Debian 7 Jessie: install the packages from Debian 8 Stretch using . See Debian source package for Calculix (forum post).

CalculiX binary
The CalculiX authors provide a pre-compiled Linux binary of the solver; it can be downloaded from the authors' website. However, since different Linux distributions have different library paths, most likely this binary will not work without making some adjustments.

To use the binary with Fedora 21, see the thread Making FEM run on linux fedora 21. For newer Fedora versions, you should compile CalculiX yourself.

If you use this binary, check that the binary is executable, that it is in the executable of your system, and that you have the necessary version of the libraries (,, , etc.) against which it was compiled. This is mentioned in the forum post FEM WB.

Use the command to see the libraries that are linked by the binary. Install any missing dependency.

Compile CalculiX
Since CalculiX is a standalone application, you can either install a binary packaged for your distribution, or compile it yourself. Any CalculiX version from 2.7.x onwards should work with FreeCAD, and since the code hasn't changed much in years, lower versions than 2.7.x may work as well.

Compiling CalculiX is a task for experienced users, requiring editing the Makefiles and build options in different platforms. See the following information:
 * Debian: Debian source package for Calculix, Gmsh 4 package available for testing in Community Extras PPA, Compiling CalculiX ccx on fedora, ubuntu and debian.
 * Fedora 27, 28, 29: Compiling CalculiX ccx on fedora, ubuntu and debian.
 * There is a CMake version of the source package in a github repository, but at the FreeCAD forums no one has reported if this package works.

Compile Netgen
Netgen was originally linked by FreeCAD when FreeCAD used OCE, the community fork of OpenCascade (OCCT). As OCE lagged in development behind OCCT, FreeCAD switched back to OCCT. This broke the linking of Netgen, which could only link against OCCT 6.9 or OCE 0.18 and below. As OCCT 7.x versions improved the core funcitonality of FreeCAD, it was decided to drop Netgen support in favor of Gmsh.

Since then some success has been achieved patching and linking newer versions of Netgen against OCCT 7.x. Nevertheless, the inclusion of Netgen with FreeCAD is still problematic.

Installing on OSX
The OSX development packages of FreeCAD may include Netgen but may not include CalculiX.

CalculiX
Voir ce message de forum FreeCAD Fem on OSX comment installer CalculiX sur OSX Les informations suivantes peuvent être obsolètes:
 * forum
 * forum

The following posts may be outdated:
 * FEM on Mac OSX, post 1
 * MacPorts users: CalculiX port test request

Further information
The FEM Workbench is under constant development. The most recent information is found in the FreeCAD forum.

If you have problems installing Netgen, Gmsh, or CalculiX, or another external tool, please search the forum first:
 * netgen site:forum.freecadweb.org
 * gmsh site:forum.freecadweb.org
 * calculix site:forum.freecadweb.org