FEM useless at the moment?

[sirpete83]

Hallo,
I try to do a thermal simulation. It is the first time i'm doing this, in the past I used simulation for eigenvalues, that worked fine after some problems.

Now i have problems with the new link "think" maybe someone has an idea how to fix.
Tried a lot of ways, part, group, reorganize everything... test with a simple blocks, but no chance, tried every build, the last one with netgen,the new without netgen :
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 32-bit
Version: 0.17.12361 (Git)
Build type: Release
Branch: master
Hash: ad457ba96b14a4c0f2a4d1da019c5c9a83bbab40
Python version: 2.7.8
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.0.0
Locale: German/Germany (de_DE)

fem_2.PNG (83.94 KiB) Viewed 1874 times

fem_1.PNG (81.6 KiB) Viewed 1874 times

attached to pictures to show the problem

[makkemal]

You need the same constraints you would for structural analysis too.
The is a coupled thermal-structural analysis solving temperature and associated displacement/stress simultaneously

[sirpete83]

I don't know what you mean Sorry.

[makkemal]

Post your file. I will show you
You need fixed or displacement constraints

[lambda]

Actually there is nothing wrong with the constraints I think. I do some thermal simulations with FEM too and it works for me.

I think something with your body is wrong: Maybe it is not a solid or compsolid?

I suggest first trying some primitive part like a cube.

Also makeing a sketch in 2D and the extruding in the Part WB works for me. (But without creating a Body with a coordinate system, like you do.)

Sometimes I had the same error in the past, but I don't remember the reason anymore. It was easy to work around for me.

[wmayer]

Now i have problems with the new link "think" maybe someone has an idea how to fix.

This is caused by a recent change on the linking of objects in different groups or bodies that adds some more restrictions. To make this working again the code must be slightly changed.
Since I am not too familiar with the FEM wb it would be good to give step-by-step instructions how to force this error message.

[bernd]

I assume it is about this one https://forum.freecadweb.org/viewtopic.php?f=18&t=24376

I did not have the problem yet and furthermore not yet had time to have a look at this, to be honest ...

[bernd]

Ahh, it is because I have not started to work with bodies ...

[sirpete83]

I will try to post the file in the late evening. Or tomorrow...

Bernd: Did I understand it is not practical at the moment, by the way I am doing it?

[bernd]

I will try to post the file in the late evening. Or tomorrow...

Bernd: Did I understand it is not practical at the moment, by the way I am doing it?

no it means I'm not up to date with FreeCAD PDN tools ... and thus FEM is not, because no other one did have a look at this ... For the models I use I do not realy need PDN. ATM I'd like to finishize the GSoC stuff ...