Assign Coefficient of thermal expansion (CTE) / temperature to RBE2 Element

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hello,

 

I am using Optistruct for my thermoelastic simulation. I am investigating the thermal expansion of some components connected with RBE2 elements. 

 

I am trying to assign CTEs to RBE2 elements. I have read that this is possbile by doing a card edit (screenshot).

 

After that I have chosen the nodes of the RBE2 elements (2 rigid spiders and a RBE2 connection for a bolt) and assigned the Temperature increase (BCs -> create -> Temperature).

 

I have included in the load step the initial temperatures for all nodes with subcase TEMP and the increased temperatures with subcase TEMP_LOAD.

 

Unfortunately the RBE2 element is not expanding. Surrounding solids and shells are normally expanding.

 

I guess that the CTE is assigned, but somehow the RBE2 element does not know, that its temperature increased... Does somebody have experience with that.

 

Thank you for your help.

 

Vincent

<?xml version="1.0" encoding="UTF-8"?>csrd edit.PNG

<?xml version="1.0" encoding="UTF-8"?>ceramic.PNG

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Answers

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited January 2019

    Which version of OptiStruct you have used for analysis? Can you please share us the .out file of the run.

     

    Note: If using any lower version of OptiStruct 14.220 then please migrate to 14.230(rbe2 thermal expansion issue fixed) or latest version 2018.0.1 

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2019

    Hello Rahul,

     

    i am using the latest version of optiscruct.


    Anyway, I solved the problem by repeating every step properly and the RBE2 element is expanding now. It seems like works exactly like I described.

    (assign alpha by card edit -> assign initial temp -> assign increased temp -> solve).

     

    Another question: As I need to card edit every rbe2 spider, is there the possibility to card edit all the elements at once?

    When I selected mutiple spiders and try to edit it, I get the message: 'No valid entities were selected'

     

    Thank you for your help.

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited January 2019

    Please set the config to rigidlink instead of rigid while card editing.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2019

    Thank you. What is the difference between both?

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