spacether / pycalculix

Python 3 library to automate and build finite element analysis (FEA) models in Calculix. Meshing uses Calculix or GMSH.
http://justinablack.com/pycalculix/
Apache License 2.0
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*ERROR in e_c3d: nonpositive jacobian determinant in element 193 #33

Closed tomchallands closed 6 years ago

tomchallands commented 6 years ago

OS: Linux Mint 18.3 (Ubuntu 16.04.2) Python 3.6.3 Pycalculix 0.9.4 Calculix 2.13

I am receiving the following error messages with the hole-in-plate-full.py example from:(https://github.com/spacether/pycalculix/tree/feature/adds_samples_testing

I assume it must be something to do with how the materials are set for the elements though could not be sure.

The 'ERROR....' message repeats several times over for elements 191-193

Any pointers to solving greatly appreciated.

Tom

` *ERROR in e_c3d: nonpositive jacobian determinant in element 193

Factoring the system of equations using the symmetric spooles solver Using up to 1 cpu(s) for spooles.

Using up to 1 cpu(s) for the stress calculation.

Job finished

Solving done! Reading results file: hole-kt-study.frd Reading nodes Traceback (most recent call last): File "hole_kt_study.py", line 88, in prob.solve() File "/usr/local/lib/python3.5/dist-packages/pycalculix/problem.py", line 285, in solve self.rfile.load() File "/usr/local/lib/python3.5/dist-packages/pycalculix/results_file.py", line 92, in load self.read_frd() # read nodal results File "/usr/local/lib/python3.5/dist-packages/pycalculix/results_file.py", line 1053, in read_frd ','.join(base_classes.RESFIELDS[mode])) KeyError: 'off' `

spacether commented 6 years ago

Thank you for reporting this. Sorry to hear that the sample file isn't working. I am working on an update which will resolve this issue across operating systems and gmsh/calculix versions.

When are you seeing the: ` *ERROR in e_c3d: nonpositive jacobian determinant in element 193 Errors, during solving?

Can you try using the latest version of Calculix from: https://github.com/spacether/pycalculix/tree/feature/adds_samples_testing And report back?

If you are still getting the error: KeyError: 'off' Then the issue is probably that the .frd file is formatted in a slightly weird way. When I release v0.9.5 I will make sure that it fixes this issue.

spacether commented 6 years ago

Version 0.9.5 was released today. I successfully ran pycalculix hole-in-plate-full.py without any errors raised on: Ubuntu 16.04.3 (64 bit) Python: 3.5.2 Pycalculix: 0.9.5 Calculix 2.9 Gmsh 2.10.1