I am a long time user of FreeCAD, and I have usually been able to somehow get the FEM module to work even though it always required at least one day of adjustments even for simple models.
I am now required to perform a thermomechanical simulation on a slightly more complex part, which you can see here:
I have spent the better of two full work days to simply get the meshing and materials into a state where the .inp file can even be written instead of spending 1600 seconds and telling me it fails. Gmsh appears to be unsuitable in my case, for the mesh result has many elements with non-positive jacobians. I have therefore reverted to using the Netgen mesher.
Anyways, the model is now in a state where the .inp file can be written, which takes around 8 minutes. However, no matter what I do, I cannot get the simulation to run without errors, not even an extremely basic mechanical one with only a single movement constraint. I would highly appreciate it if someone could attempt to run the simulation in the file and let me know if the problem is real, or just caused by some quirk of my local environment. You can download it here.
The error appears to be related to non-positive jacobians, but I am at a loss as to what I can do to perform meshing in a way that does not produce non-positive jacobians. See the first line in this error output from the Report view:
Code: Select all
CalculiX returned an error due to nonpositive jacobian determinant in at least one element Use the run button on selected solver to get a better error output. Error() We will load the ccx frd and dat result file. Read ccx results from frd file: C:\Users\magla\AppData\Local\Temp\fcfemsolv_rontsnqf\FEMMeshNetgen.frd We have nodes but no results in frd file, which means we only have a mesh in frd file. Usually this happens for analysis type 'NOANALYSIS' or if CalculiX returned no results because of nonpositive jacobian determinant in at least one element. Traceback (most recent call last): File "C:\Users\magla\Desktop\FreeCAD_0.19\Mod\Fem\femguiobjects\_ViewProviderFemSolverCalculix.py", line 308, in calculixFinished self.fea.load_results() File "C:\Users\magla\Desktop\FreeCAD_0.19\Mod\Fem\femtools\ccxtools.py", line 1122, in load_results self.load_results_ccxfrd() File "C:\Users\magla\Desktop\FreeCAD_0.19\Mod\Fem\femtools\ccxtools.py", line 1131, in load_results_ccxfrd importCcxFrdResults.importFrd(frd_result_file, self.analysis, 'CCX_') File "C:\Users\magla\Desktop\FreeCAD_0.19\Mod\Fem\feminout\importCcxFrdResults.py", line 192, in importFrd return res_obj UnboundLocalError: local variable 'res_obj' referenced before assignment
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.18024 (Git)
Build type: Release
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United Kingdom (en_GB)