Is it possible to do coupled analysis(thermal - structual) on Nastran?

[shimazaki.kc]

Hi all,

I would like to do coupled analysis(thermal - structual) on Nastran.

Can I do that on Nastran? 

If it is possible, I would like to know the procedure.

I hope you can see the attached image for more details.

Best regards

[John_Holtz]

Hi @shimazaki.kc 

I see the image in your PDF, but I do not understand what you are asking. If you want to calculate the expansion due to the temperature, this tutorial (Autodesk Inventor Nastran 2022 Help | Tutorial B6: Heat Transfer and Thermal Stress Analysis of an E...) or this article (Autodesk Inventor Nastran 2022 Help | How to perform a thermal expansion/ thermal stress in Inventor...) should help.

If you need to simulate different physics, please write a description of what effects you want to simulate.

John

[shimazaki.kc]

Thanks for your comment.
I would like to see how the surface of partB deforms and what shape it takes when I set the surface temperature of partA to 473K and press at 50N towards partB (298K). This is a dynamic analysis.

[John_Holtz]

Hi @shimazaki.kc 

Did the tutorial or article answer any of your questions? What aspect of your analysis did they not answer?

What we need to know is if and how the load affects the temperature calculation, and how the temperature affects the stress calculation. For example,

1. If the parts are steel and 500 mm in diameter, the 50 N load does very little to the displacement. Therefore, the temperatures can be calculated using a transient heat transfer analysis without worrying about the 50 N load. Then the temperature results can be used to calculate the thermal expansion.
2. If the parts are bubble gum and 5 mm in diameter, the 50 N load changes the contact area, and the changing contact area affects the heat transfer analysis.
3. Does the temperature change the material properties so that the contact area changes significantly as part B heats up and the load is applied?
4. Is the load applied first? Is the load applied slowly while the heat is transferred from A to B? Is the load applied after parts A and B come to a steady state temperature?

In other words, if you were to hire someone to run this analysis for you, they need to know all the details so that the analysis can be setup. Without knowing those details, no one can say "yes it can be done in Inventor Nastran" or "no it cannot be done in Inventor Nastran because of ....".

Based on the tutorial and article, Inventor Nastran can perform a transient heat transfer analysis which is independent of a stress analysis. It can transfer the temperature from one time step to a stress analysis which will give the stress and displacements due to the temperature and other loads. You can run different stress analyses using a different time step from the heat transfer analysis to see how the part deforms at different temperatures.

I hope this helps.

John

[shimazaki.kc]

Hi @John_Holtz ,

Thank you for your reply.
I checked the tutorial you mentioned. However, that tutorial only evaluates thermal stresses, and what I want to do is a coupled unsteady thermal and structural analysis. I want to see the shape of the deformation when a certain shape of hot metal (SUS) is pressed against a certain shape of plastic (LCP). Sorry, about the load, 50N was a mistake for 500N. As attached, it takes 3 seconds to crush about 3mm. I would also like to take into account that when part B is heated and loaded, the contact area will change significantly and thus the material properties will change. Attached is a simple model as an example, but I would like to develop another model. Am I making myself clear?

Best regards,

Kyota

[John_Holtz · Accepted solution]

Thanks Kyota. That description makes it clear.

Inventor Nastran cannot do that type of coupling between stress and heat transfer. The stress analysis can not change the heat transfer analysis.

The only coupling available is using the heat transfer results (temperature) in the stress analysis to calculate the thermal strain (including temperature dependent material properties).

John

[shimazaki.kc]

Hi @John_Holtz ,

I'm glad you understood it. And I understood nastran cannot do that.

Thank you for your response.I'm grateful for your help.

Kyota