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Thermal stress analysis

Hello, I am currently performing a thermal stress analysis with sequential load steps, which comprises two nonlinear static analysis steps. In the first load step, a global temperature change is applied to the structure to obtain thermal deformation results. How can I enable the second analysis step to conduct new analyses based on the thermal deformation achieved from the first step?

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Accepted answers

Alberto Campagna

This is happening because you have to keep the temperature applied in the 2nd loadcase. Try with this.

thermal.fem

Alberto

All comments

Alberto Campagna

Hi,

if both loadcases are mechanical, you have to enable the continuation card CNTNLSUB in the second loadstep. Refer to the documentation:

https://help.altair.com/hwsolvers/os/topics/solvers/os/cntnlsub_sub_r.htm?zoom_highlight=CNTNLSUB

Kind Regards

Alberto

h_h

In the first load step, I will apply a global temperature change (temperature reduction) to the entire structure, and the structure should then retain the state after thermal deformation (shrinkage). In the second load step, I will impose a forced displacement load and reference the first analysis step via the CNTNLSUB card. However, based on the results, the thermal deformation rebounds to the initial position, and the expected effect has not been achieved. How should I resolve this issue? Attached is my model—could you please inform me of the necessary setup adjustments? Thank you very much.

thermal.hm

Alberto Campagna

This is happening because you have to keep the temperature applied in the 2nd loadcase. Try with this.

thermal.fem

Alberto

h_h

It's very helpful. You mean that I also have to check TEMP_LOAD in the second analysis step, right？

Alberto Campagna

Correct, otherwise the temperature is removed from the second loadstep and the model goes back to the original deformation.

h_h

OK, thank you very much!