FEM: Added read nastran95 inp file ability in FemMesh.cpp

[ceanwang]

Forum talk at here https://forum.freecadweb.org/viewtopic.php?f=18&t=51569

[luzpaz]

@ceanwang why did you close it ?

[ceanwang]

Seems nothing is happening. I give up.

[luzpaz]

@berndhahnebach ping

[berndhahnebach]

have some patience. I am really busy ... christmas time is familly time ... Furthermore there are some dead lines in my daily job before christmas ...

[luzpaz]

@berndhahnebach any idea at what point you'll have time to address this PR ?

[wwmayer]

I have merged it now.

It's a bit weird that the same file extension (.inp) is used for Abaqus and Nastran-95 files. The difficulty of this PR was that it doesn't handle both formats at the same time but basically disabled the Abaqus support.

So, I solved it this way: if an inp file is given then FreeCAD first tries the Abaqus importer and if afterwards the mesh is empty (i.e. it has no nodes) the Nastran-95 imported is used.

Btw, here is a link to a file that can be used for testing: https://forum.freecadweb.org/viewtopic.php?f=18&t=39234&start=10#p412743

[ceanwang]

Thanks.  The question was raised in the forum, but no input. I was thinking a FEM WB setting to choose which importer to use for inp extension: https://forum.freecadweb.org/viewtopic.php?f=18&t=51569&start=10#p443787 Abaqus must copied Nastran. It’s good FC can support a Free and open source one.  

[berndhahnebach]

It's a bit weird that the same file extension (.inp) is used for Abaqus and Nastran-95 files. The difficulty of this PR was that it doesn't handle both formats at the same time but basically disabled the Abaqus support.

BTW: this was the reason I did not merge it myself earlier.

[berndhahnebach]

https://forum.freecadweb.org/viewtopic.php?f=18&t=51569&p=485503#p485503