Menu

Discussion Forum

New Discussion
Filter

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Thermal Expansion 2D don't agree with analitical value of 3D

Posted Jan 12, 2018, 8:59 p.m. EST Structural & Acoustics, Results & Visualization, Structural Mechanics Version 5.3a 2 Replies

Gabriel Gama
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi,

I've been using the 2D Thermal Expansion Module to verify some results. I've built a copper bar with 300 x 10x3.5 (The 3.5was put on thikness of solid mechanic module). It shows that the displacement was 5.2 when subjected to an enhance of 800K. The theoric value gives . This is a diference abaut 30%, even thoug it is a very simply simulation. But if I simulate the same values for a 3D sistem, the result agree with theory. Why is there this difference? Is it possible that I've been using the of displacement measurement wrongly?

Thanks and best regards

Gabriel Gama

https://drive.google.com/open?id=1fpRo2YUGzLP_6pEzkgatqxFobOLdtT3- https://drive.google.com/open?id=1eAWI9lId5ZE1Am88VwszdIX9NqewXKYH

Attachments:

2 Replies Last Post Jan 15, 2018, 7:28 p.m. EST
Edgar J. Kaiser Certified Consultant
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 7 years ago Jan 13, 2018, 6:18 a.m. EST
Updated: 7 years ago Jan 13, 2018, 6:23 a.m. EST

Gabriel,

this is a thin plate, so you should use the plane stress approximation instead of plain strain in the solid node. The predescribed displacement is not required and imposes a deviation from the analytic solution.

Cheers Edgar

-------------------
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Gabriel, this is a thin plate, so you should use the plane stress approximation instead of plain strain in the solid node. The predescribed displacement is not required and imposes a deviation from the analytic solution. Cheers Edgar
Gabriel Gama
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 7 years ago Jan 15, 2018, 7:28 p.m. EST

Dear, E. J. Kaiser.

I'd like to thank you. I made like you said and worked.

Best regards,

Dear, E. J. Kaiser. I'd like to thank you. I made like you said and worked. Best regards,

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content