stiffness matrix problem
stiffness matrix problem
I don't know why I can't get the right stiffness matrix result.
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- model.rar
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kesavapraba
- Posts: 468
- Joined: Sat Mar 28, 2020 2:25 pm
Re: stiffness matrix problem
Hi, I observed two issues with your model
1] Using NormUnbalance tester with Penalty constraints: Doing so will cause convergence issue and analysis failure. It is because Penalty constraints can make the right side of system of equations to have large residual forces since the constraint adds artificial springs with high stiffnesses (Penalty factors). Use NormDispIncr in such case.
2] The factors for the stiffness in the GimmeMCK integrator are set to zero (instead mass factor is set to 1!): Please look at the attached figure. You set 1.0 either for Kinitial (initial stiffness matrix) or Kt (tangent stiffness matrix), as per your requirement.
1] Using NormUnbalance tester with Penalty constraints: Doing so will cause convergence issue and analysis failure. It is because Penalty constraints can make the right side of system of equations to have large residual forces since the constraint adds artificial springs with high stiffnesses (Penalty factors). Use NormDispIncr in such case.
2] The factors for the stiffness in the GimmeMCK integrator are set to zero (instead mass factor is set to 1!): Please look at the attached figure. You set 1.0 either for Kinitial (initial stiffness matrix) or Kt (tangent stiffness matrix), as per your requirement.
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- GimmeMCK.png (30.46 KiB) Viewed 594 times
:: With best wishes ::
Prabakaran Kesavan
Prabakaran Kesavan