Freecad + CalculiX

About the development of the FEM module/workbench.

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calc4fem
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Freecad + CalculiX

Postby calc4fem » Sat Jun 22, 2013 9:44 pm

One of the best open programs for Fea analysis is CalculiX. (calculix.de, calculixforwin.com ). Now it works thru the netgen mesher and step format. The problem that the step has units inside and the mesh should be translated with using units other than mm. The same problem appears with Elmer-FEM. It came from opencascade kernel but generally it is bot a big deal it you know about that.
Here are some exapmles of meshing STEP geometry in Netgen: http://youtu.be/ZYF2IBd3Fr0 My questions is what the next step in the integration with open-source FEA?
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jriegel
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Re: Freecad + CalculiX

Postby jriegel » Sun Jun 23, 2013 8:55 pm

Next steps in the FEM module is finishing the preprocessor (meshing with NETGEN works already) and then some basic postprocessing.
Stop whining - start coding!
calc4fem
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Re: Freecad + CalculiX

Postby calc4fem » Wed Jul 10, 2013 7:16 am

jriegel wrote:Next steps in the FEM module is finishing the preprocessor (meshing with NETGEN works already) and then some basic postprocessing.
Thank you for the answer. Basically, Netgen supports STEP-IGES-BREP cad geometry, and it is not a big deal to use Freecad with Netgen (or with GMSH)
Here are couple of new samples:
http://youtu.be/eF3Qp77iNTY
http://youtu.be/7JzNsp6UKmI
The possible problem, that it is difficult to obtain normal mesh by default, some additional steps and options required.
Unfortunately I can't help to your team with programming but I will test new features when it appears.
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dubstar-04
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Re: Freecad + CalculiX

Postby dubstar-04 » Tue Feb 18, 2014 8:53 pm

Whats the best way to install calculix on Ubuntu 13.10?

I have been trying to find a PPA.

Thanks,

Dan
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r-frank
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Re: Freecad + CalculiX

Postby r-frank » Tue Feb 18, 2014 9:43 pm

Hello.

Maybe you will try your Luck with these instructions.

There is another Tutorial available here. Maybe use Google Translate ;)

If you do give it a try, please report back if it worked.

Thanks
Roland
Deutsche FreeCAD Tutorials auf Youtube
My GrabCAD FreeCAD-Projects
FreeCAD lessons for beginners in english

Native german speaker - so apologies for my english, no offense intended :)
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NormandC
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Re: Freecad + CalculiX

Postby NormandC » Thu Sep 11, 2014 11:07 pm

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TT-RS
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Re: Freecad + CalculiX

Postby TT-RS » Fri Nov 28, 2014 2:33 pm

I agree that CalculiX is the way to go. There are few other good opensource systems (ELMER, Z88,...), but CalculiX is - I think - the most popular of them and in the area of interest of many people. It is strong and mature package.

However CGX is terrible to use, if FreeCAD could it replace in future (with some extra functionality, like handling assemblies with contacts detection and "naming selection" fucnctionality) it would be very nice. This would bring many users (of CalculiX) to FreeCAD also. IThere is strong demand for such program, because there aren't any cheap or free tools to pre-process CalculiX cases (Hopefully there are some free post-processors).

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Re: Freecad + CalculiX

Postby spacether » Wed Dec 31, 2014 7:15 pm

I'm excited about the progress being made in the FEM module. Of the free FEA options available, I think that Calculix, Elmer, and Code-Aster are all great FEA programs to hook Freecad up to.

Out of those options, Calculix has a very straightforward input file syntax, and it is mature as TT-RS said.
I was also frustrated with the lack of easy to use FEA freeware, so I wrote a python library to wrap around Calculix:

http://justinablack.com/pycalculix/
It allows the user to build, mesh, solve, and post-process 2D Calculix models (plane stress, plane strain, and axisymmetric) from within Python.
Perhaps my code can provide some insight into interfacing with the Gmsh mesher, which it uses.
Gmsh can produce quads, tris, tets, hex, etc. elements.

Pycalculix is good for 2D trade studies, but in the long term, users need easy to use FEA freeware built into a CAD program, and I'm happy to see that Freecad is making progress in this area.
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TT-RS
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Re: Freecad + CalculiX

Postby TT-RS » Tue Jan 06, 2015 4:07 pm

I know PyCalculiX, first time I found it in Google about 2-3 weeks ago. Nice work, it's a pity it doesn't cover 3D problems. But your approach and using Python is very good. FYI there is another CAE 2D software: Agros2D - also opensource, but much bigger and more functional/sophisticated (this is Multiphysics package) - really worth checking!.

FreeCAD has already some basic pre- and post-processing functionality and it works (I used Windows snapshots for this) really OK. I like how FC handle boundary conditions. It is easy and fast, as were you use SolidWorks Simulation or sth. similar. I like it. Contrary CGX is a nightmare to use. I hope FC will also handle assemblies in FEM workbench. Today, FEA without assemblies and automatic contact detection is useless ;)
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