strange result for contact constraint

About the development of the FEM module/workbench.
UR_
Posts: 44
Joined: Tue Jan 03, 2017 8:42 pm

strange result for contact constraint

Postby UR_ » Tue Mar 14, 2017 9:58 pm

Hello,
I am running into an strange issue, while doing some analysis containing contact constraints.
There was something wrong with provided results.

So i setup appended test case with known analytical solution
doppelbalken.png
doppelbalken.png (142.12 KiB) Viewed 129 times

doppelbalken.FCStd
(790.52 KiB) Downloaded 3 times


Here deflection should be
[/quote]
analytical.png
analytical.png (38.64 KiB) Viewed 129 times


I have tested two binaries for windows
cygwin build:
https://github.com/easyw/ccx_prool/blob/master/CalculiX-bin-folder/win64/ccx2_11_MT-64.exe
referenced here:
https://forum.freecadweb.org/viewtopic.php?f=3&t=17068&start=30#p137816
with this result
result easyw.png
result easyw.png (22.55 KiB) Viewed 129 times


and this

mingw64 build:
https://github.com/ddfem/ccx_mingw64/blob/master/ccx_2.11_MT.exe
with this result
result ddf.png
result ddf.png (20.87 KiB) Viewed 129 times


Have i done something wrong, or overseen? :?

Done with:
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.10460 (Git)
Build type: Release
Branch: master
Hash: 91c59c7910436c44ede608e29d9a90a287121a11
Python version: 2.7.8
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.0.0
User avatar
bernd
Posts: 3924
Joined: Sun Sep 08, 2013 8:07 pm
Location: Zürich, Switzerland

Re: strange result for contact constraint

Postby bernd » Tue Mar 14, 2017 10:39 pm

I have not yet tested your files. What I can tell is different ccx binaries could give different results, yes. I had similar issue. You may read this topic: https://forum.freecadweb.org/viewtopic.php?f=18&t=20276 The maintainer said some ccx uses patched libraries for compiling.

I'm gone try your example too.