🎉Community Raffle - Win $25

An exclusive raffle opportunity for active members like you! Complete your profile, answer questions and get your first accepted badge to enter the raffle.

Join and Win

Non-Linear Thermal Expansion Analysis

Turbokraken

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

Find more posts tagged with

English

OptiStruct

Accepted answers

All comments

Rahul Rajan_21763

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

Unable to find an attachment - read this blog

Turbokraken

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

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

Turbokraken

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

Rahul Rajan_21763

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

Turbokraken

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

Please refer to comments from help of OptiStruct version 2018.0.1.

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