Non-Linear Thermal Expansion Analysis

Turbokraken
Turbokraken Altair Community Member
edited October 2020 in Community Q&A

Hi Everyone,

 

I am currently looking at how a composite plate with a certain Lay-Up will deform when temperature is applied. However with this material the coefficient of thermal expansion changes with temperature. I do have sufficient data points to model this but I am not sure how.

I am using a composite material (MAT8) and I would like to have a non-linear thermal expansion coefficient (A1). I have looked into non-linear stress/strain modelling with MAT1S cards but I do not think this is what I need.

I already have a table with the values I need (as a TABLES1, is this correct?)

 

I just need a hint to the right direction. :)/emoticons/default_smile.png' srcset='/emoticons/smile@2x.png 2x' title=':)' width='20' />

 

Thank you very much for reading and I hope you can help me.

 

EDIT: Also, I am using OptiStruct. Is this solver cabale of doing this? I am not familiar with any other.

 

Best Regards,

Lennart

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Answers

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

    Please check if MAT8/9ORT along with MAT4 helps (TABLEM). Refer sample deck.

    Unable to find an attachment - read this blog

  • Turbokraken
    Turbokraken Altair Community Member
    edited January 2019

    Hi Everyone,

     

    ok small update here:

    I managed to put in a table (TABLEM1) and entered my temperature/CTE data points. I also activated the required MATT8 card in the material card.

    But no matter what I do, the MATT8 card is ignored.
    What type of load step do I need to use? Right now I am using the 'Generic' One.

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

    Can you share us the .fem file with ftin link available in my signature.

  • Turbokraken
    Turbokraken Altair Community Member
    edited January 2019

    Due to this work being confidential, I unfortunately cannot share it...

     

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

    Which version of OptiStruct solver you are running? Can you share us .out file of the run atleast.

  • Turbokraken
    Turbokraken Altair Community Member
    edited January 2019

    Dear Rahul,

    I have copied two sections from the .out File that I believe are important:

     

     *** WARNING # 1376
     Field 11 in MATT8 2 defines temperature dependence,
     but the same field on MAT card is zero or blank.
     Respectively, this zero value will be processed
     by the temperature-dependent tables.
     With TABLEM1, the value will be replaced by the table value.
     With TABLEMi(i=2,3,4), the value will remain as zero.
     
     *** WARNING # 1377
     Temperature-dependent materials are present in Linear Static subcases
      without SYSSETTING,TLOADMAT,1/2. TEMP(BOTH) or TEMP(MAT) (depending on their
      order) will be used to update material properties for temperature-dependent
      materials in linear static subcases. If TEMP(BOTH) and TEMP(MAT) are not
      present, then TEMP(INIT) is used instead.

     

    Does the last warning tell me that that for the linear static subacase I need to make additional adjustments?

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

    Please refer to comments from help of OptiStruct version 2018.0.1.

    <?xml version="1.0" encoding="UTF-8"?>MATT8 Comments.JPG

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