Error #179
Description: I'm doing a torional Stiffness study of a monocoque, I belivie I've setup the model correctly following this tutorial https://www.youtube.com/watch?v=U2cJpttNK2c but I keep getting the error #179.
*** ERROR # 179 *** The dependent d.o.f.s of multi-point constraints produces a singular matrix. This may be caused by a circular dependency in which a d.o.f. is indirectly dependent upon itself.
I've tried editing the rigid bodies and double checked all the RBE2's and believe they have been done correctly so not really sure how to fix this error.
Any support would be very much appreciated.
Thanks,
Sam
Product/Topic Name : Hypermesh
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Thank you for your help, I'm using 2024.1 with student licence but don't know if that makes a difference.
Many thanks,
Sam
Altair EmployeePerhaps a node limit limitation? Your model is quite big. You could probably coarsen it quite a bit and still get reasonable results
https://web.altair.com/altair-student-edition
I made the mesh coarser reducing the number of elements from around 900k to 50k but still getting the error #179. The error could be coming from how I'm running my .fem file on the solver. I'm currently just pressing the ANALYZE button in the ANALYZE tab and then running the input .fem file created. Do you have an idea of how this could be going wrong?
Altair EmployeeI see the same message in 2024.1, but not in 2025.0. Possibly a resolved issue?
Otherwise here is the specific error reference
I'll try go download 2025.0 and see if it work.
Thanks,
Sam
What version of Optistruct are you using?
It runs for me without issue in 2025.0