Simple impact simulation do not converge
Altair EmployeeHi,
I am trying to learn how to realize an impact test with RADIOSS. I folowed this tutorial from Altair University: https://www.youtube.com/watch?v=aDeNhQFvqjE&t=304s
I folowed every steps of this video but my simulation seems not to converge... I stopped it after 30 minutes and here is the last iteration message:
You can see that after 1715s I had an error of 99.9%, and the remaining time was increasing again and again (so the response couldn't converge)
Before running the test, I had no error in the model checker:
And here is the picture of mu model:
I attached a file to this post which is the model i use for this simulation.
Thank you very much for the help. Quentin BERMOND
Answers
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help？
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Hi,
the shared model had some issues:
- unit consistency: input units were defined as kg, m, s in the begin card, but initial velocity and material (steel?) had values more consistent with tonne, mm, s unit system
- impactor with 34000 mm/s (122.4 km/h) initial velocity and 450 kg mass has too much initial kinetic energy for the plate to absorb
- animation output frequency (ANIM/DT) was too low to capture deformations
- contact was modified
The model is able to solve with failure plastic strain (EPS_p_max) defined. Without material fracture the model will fail to solve as the loading is so high the plate will undergo unrealistic deformations causing numerical difficulties.
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Thank you very much for the help, I will try to run this simulation during the week with the modifications you suggested. I would never have noticed these errors without you since these values are directly taken from the Altair Tutorial.
Best regards, Quentin
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