Problem with RBE3 in Hyperworks

Guilherme Arruda
Guilherme Arruda Altair Community Member
edited September 12 in Community Q&A

Hi, i´m working in a analysis in Hyperworks using the Optistruct as a solver

image

I need to use a remote force in this point beside the geometry and my ideia is to connect the point and the holes with rbe3 elemments, but i´m having these messages

image

and idk how to proceed, i would like to fix this errors

thank you

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Answers

  • Adriano A. Koga
    Adriano A. Koga
    Altair Employee
    edited August 2021

    Hi Guilherme,

     

    the solver will error out a message in your case, because your RBE3 needs at least 3 "legs", and non-colinear.

    As a very simple example, you can thing about a simple chair where you're going to sit. If there is on 2 legs, it won't keep stable. If you have 3 legs it will be more stable, but if all of them are aligned, then, you loose stability again.

    Maybe you could just create a single RBE3 connecting directly the nodes in your holes, instead of adding 3 different ones.

  • Guilherme Arruda
    Guilherme Arruda Altair Community Member
    edited August 2021
    Adriano A. Koga_21884 said:

    Hi Guilherme,

     

    the solver will error out a message in your case, because your RBE3 needs at least 3 "legs", and non-colinear.

    As a very simple example, you can thing about a simple chair where you're going to sit. If there is on 2 legs, it won't keep stable. If you have 3 legs it will be more stable, but if all of them are aligned, then, you loose stability again.

    Maybe you could just create a single RBE3 connecting directly the nodes in your holes, instead of adding 3 different ones.

    Hi Adriano,

    I was trying to fix the errors, but it still occurs that the elements are colinear

    The dependent node is the node i will aply the force and the independents are in the holes

    Is it possible to make it non colinear?

    thanks for the help

    image

  • Nkrainer
    Nkrainer
    Altair Employee
    edited September 11

    I have the same error with an RBE3 that's created from 8 radially distributed RBE3 elements around a circle.

    But on what direction are they collinear? they don't sit on a same axis.

    Does every RBE defines a virtual axis, and these axii are colinear and it causes the problem?

  • Rajashri_Saha
    Rajashri_Saha
    Altair Employee
    edited September 12
    Niv Krainer said:

    I have the same error with an RBE3 that's created from 8 radially distributed RBE3 elements around a circle.

    But on what direction are they collinear? they don't sit on a same axis.

    Does every RBE defines a virtual axis, and these axii are colinear and it causes the problem?

    Hi Niv,

    Please share your .fem file for investigation.

    Thanks

    Rajashri

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