Bug in RigidLink beam?

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Lost
Posts: 16
Joined: Sun May 26, 2013 2:08 am
Location: National Technical University of Athens

Bug in RigidLink beam?

Post by Lost »

Hello! I am trying to use in series a rigidLink beam element and then an equalDOF constraint (for a zero-length element), however I have a problem.
When creating the zero-length element to use after a rigidLink beam and connecting its nodes with equalDOF (all 6 DOFs) the eigenvalues are different than those when using only the rigidLink beam element. However, they are the same as if I were using two equalDOFs in series. Is there a possibility that when a constraint comes after a rigidLink beam, it is treated as equalDOF 1 2 3 4 5 6;
Thanks!
Lost
Posts: 16
Joined: Sun May 26, 2013 2:08 am
Location: National Technical University of Athens

Re: Bug in RigidLink beam?

Post by Lost »

Hm, maybe I haven't followed the rule for the Transformation command:
2) If multiple nodes are constrained, make sure that the retained node is not constrained in any other constraint.
I'll look into it and post again if the problem persists.
Lost
Posts: 16
Joined: Sun May 26, 2013 2:08 am
Location: National Technical University of Athens

Re: Bug in RigidLink beam?

Post by Lost »

Yep, replacing the equalDOFs with very rigid materials in the ZeroLength Element fixed the problem! :D
fmk
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Re: Bug in RigidLink beam?

Post by fmk »

another option would have been to use the Penalty method for enforcing the constraints.
Lost
Posts: 16
Joined: Sun May 26, 2013 2:08 am
Location: National Technical University of Athens

Re: Bug in RigidLink beam?

Post by Lost »

Thanks for the answer! I prefer to use the Transformation constraints though so I don't have to change and check the penalty factors and if the results are correct.
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