RBE2 + CBUSH force transfer

Rafał Szypulski_22596
Rafał Szypulski_22596 Altair Community Member
edited August 2022 in Community Q&A

Hello!

I'm trying to get a better understanding of CBUSH and RBE2 elements. I've created a simple model (hm file attached below). I would like to simulate a remote force acting on a bar2 element (PBEAML) transferring both force and torque. The bar2 is connected to the independent node of radially placed rigids through a CBUSH element with very high stiffness on all DOFs except for the torsional one round the bar's axis (6th one in this case). 

The results are shown below. The CBUSH seems to be working pretty well, however, the rigid element connecting the force to my 1D elements starts to rotate uncontrollably around the bar's axis. How should I fix the model in order to introduce the remote force correctly? Thank you so much! 

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Nodes 1 and 2 are connected with an RBE2 element with all DOFs checked
CBUSH element connects two coincident nodes - an indepenent node of the radially placed rigids and one on the nodes on the bar (3).
The RBE2s transfer all translational DOFs to the dependent nodes.

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Answers

  • Robinson Ferrari_20451
    Robinson Ferrari_20451
    Altair Employee
    edited August 2022

    Hi Rafa,

    Please take a look at the file attached. I modified the stiffness to 100N.mm/mm.

    Use DOF123456 to the rbe2 since you are already using CBUSH with rotational stiffness on the z-axis.

    The result looks fine to me, please let me know if it works for you.

    If it answers your question, please mark it as correct to help others.

    Thank you very much,

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