topic Yet another new Simulation Failure. in Fusion Design, Validate & Document Forum

Yet another new Simulation Failure.

jasonhomrighaus — Tue, 15 Nov 2016 17:13:32 GMT

Heres the latest Failure message

_____ 2016-11-15 11:57:48 _____
Document is being uploaded to cloud storage. Cloud job is pending.
Scheduling job.
Job scheduled successfully.
118784 Tetrahedra : 100.0% of elements (100.0% of volume)
Face Angle min: 4.23, max : 162
Dihedral Angle min: 6.53, max : 165
Worst shape ratio : 22.9 on element 64819
Worst aspect ratio : 9.62 on element 7408, shortest edge: 0.000166, longest : 0.0562
Lowest collapse ratio : 0.0748 on element 46495
Worst Jacobian ratio : 3.16 on element 56917
Base mesh: 188831 nodes, 118784 elements
Solver mesh: 188831 nodes, 118784 elements
Job has finished with errors. Receiving results.
Error: FATAL ERROR E5004: STIFFNESS MATRIX SINGULAR OR NON-POSITIVE DEFINITE
Error: Solver Error
Error: An error occurred while solving the model.

Re: Yet another new Simulation Failure.

AndrewSears — Tue, 15 Nov 2016 19:13:58 GMT

Jason,

Can you attach the model so I can take a look?

Thanks,

Andy

Re: Yet another new Simulation Failure.

jasonhomrighaus — Tue, 15 Nov 2016 21:31:17 GMT

Here you go.

Re: Yet another new Simulation Failure.

AndrewSears — Wed, 16 Nov 2016 01:11:43 GMT

Here is the link to the Nastran error code. E5004 Error def. This error is telling you that your model is not stable. Inspecting your model, the constraint is the issue.

You applied a fixed constraint to a super small area. This is not a realistic location for the constraint given that you defined four, 4kN bearing loads. Modify this and go to item 2.

When I modified the location for the constraint, the model solved.

2. You have sick mesh refinements. This does not stop you from solving but should be addressed.

I am reaching out to others to see if something can be done to warn you if mesh refinements are sick, as with your model.

Andy