FEM Install/it

Introduzione
Per eseguire una Analisi agli elementi finiti (FEA) utilizzando il modulo FEM FreeCAD si avvale di due programmi esterni. Uno è utilizzato per generare la Mesh FEM e l'altro per risolvere il sistema di equazioni.

FEM Solver
For solving the system of equations CalculiX is used. See http://www.calculix.de/ FreeCAD writes an CalculiX input file starts CalculiX and reads the output of CalculiX. It means CalculiX binary is standalone and independent from FreeCAD. Because of this and since there are more possibilities to get a valid FEM-Mesh it is recommended to install the Solver first. Up To date (mid 2015) CalculiX is the only supported Solver of the FEM module.

FEM Mesh Generator
As meshing tool to create a FEM-Mesh netgen is used. See https://sourceforge.net/projects/netgen-mesher/ To use Netgen in FEM module FreeCAD needs to be compiled against netgen libraries. Apart from Netgen a common way to create a FEM Mesh is the use off GMSHMacro. Check out FEM_Mesh for the various possibilities to create an FEM Mesh in FreeCAD.

Windwos
Se viene utilizzata una versione stabile o di sviluppo prelevata da Download non è necessario installare altro ulteriore software. Netgen e Calculix sono già compresi nel pacchetto di download di FreeCAD.

Ubuntu PPA
Il modo più semplice per ottenere un Ambiente FEM che lavora su Linux consiste nell'usare il PPA Ubuntu per la propria versione. Consultare la pagina Pacchetti PPA di Ubuntu. Netgen che è il generatore FEM Mesh è giá incluso nella versione ppa. Anche Calculix è un pacchetto extra fornito dal PPA Ubuntu. Se il repositorio PPA di Ubuntu è giá aggiunto al gestore di pacchetti si può installare Calculix con: apt-get install ccx

I seguenti pacchetti FreeCAD del PPA Ubuntu contengono NetGen e Calculix:
 * Ubuntu 14.04 (Trusty Tahr)
 * Ubuntu 14.10 (Utopic Unicorn)
 * Ubuntu 15.04 (Vivid Vervet)

For Developers: There is a huge forum thread in which the creation of the Ubuntu PPA packages was disscussed. It may be usefull if the Ubuntu PPA packages needs to be updated. On Launchpad there are more than one CalculiX packages. Only one CalculiX package should be installed and any of them should work. There is a simple reason for not taking the one which was allready on Launchpad. We did not know about it (see http://forum.freecadweb.org/viewtopic.php?f=18&t=10393&start=90#p85498)

Other
On other Linux distributions you need to make sure to get the appropriate software and libraries installed yourself before using FEM workbench.

CalculiX
Since CalculiX is a standalone software you either can install a CalculiX binary or compile CalculiX yourself. Any CalculiX version from 2.7.X works with FreeCAD. Since there hasn't been much changes in CalculiX resently lower versions than 2.7.X might work as well.

Install CalculiX Binary
There are only a few Linux Distributions which are known to have CalculiX Packages in their Repositories. Following a list:
 * Arch Linux --> https://aur.archlinux.org/packages/calculix/

On the CalculiX Website it is possible to download a generic Linux binary of CalculiX. Check out http://www.dhondt.de/ Since any Linux Distribution could have different library paths it is likely possible this binary will not work out of the box at your linux distribution. Check out the following FreeCAD forum threads for more infomation:
 * Fedora 21 --> http://forum.freecadweb.org/viewtopic.php?f=18&t=10140
 * Some bash commands that may help --> http://forum.freecadweb.org/viewtopic.php?f=3&t=11830&start=20#p95741

Compile CalculiX
Compiling CalculiX is not as easy as it is with many OpenSource software. There are many different resources at FreeCAD forum and the internet. Check out the following:
 * Debian --> http://forum.freecadweb.org/viewtopic.php?f=4&t=5975&start=10
 * There is a CMake Repository on github, but at FreeCAD forum noone has reported if this one works
 * https://github.com/ricortiz/CalculiX-cmake

Netgen
There have been mixed results with the Netgen mesher and the compilation of FreeCAD with Netgen support.
 * ToDo

Further Informations
The FreeCAD forum is a very good resource for informations in this regard. Check out google search on FreeCAD forum page by :
 * calculix site:forum.freecadweb.org
 * netgen site:forum.freecadweb.org

OSX
Né NetGen né Calculix sono inclusi nei pacchetti di FreeCAD scaricabili daDownload

CalculiX
Consultare questa discussione nel forum.

Netgen
There is no known documantion source for FreeCAD and netgen on OSX. As stated before use GMSHMacro and check FEM_Mesh for the various possibilities to create an FEM Mesh in FreeCAD.