×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Huge errors of nonlinear transient coupled thermal-electrical problem (linear vs quadratic elements)

Huge errors of nonlinear transient coupled thermal-electrical problem (linear vs quadratic elements)

Huge errors of nonlinear transient coupled thermal-electrical problem (linear vs quadratic elements)

(OP)
Dear Expertises

I have performed coupled thermal-electrical analyses, which involves fully coupled nonlinear transient thermal-electrical equation. For the analyses, only brick elements (default type) were considered.
When comparing the solution from linear brick elements with one from quadratic elements, there were huge difference in tempeature. In some regions (space), using quadratic elements approximated negative tempeature profile, which must be wrong...... Why there is huge difference in converged solutions from linear element and quadratic element??
From my understanding, the quadratic elements more accurately approximate the solutions in msot cases. Is there any exception??

Simply explaining my model, the case is 3D composite laminate (16 plies) with temperature-dependent thermal/electrical conductivity and nonlinear thermal radiation boundary.

Best regards,
Juhyeong Lee

RE: Huge errors of nonlinear transient coupled thermal-electrical problem (linear vs quadratic elements)

Read that:
Users Manual 6.5.2 Uncoupled heat transfer analysis -> Spurious oscillations due to small time increments

RE: Huge errors of nonlinear transient coupled thermal-electrical problem (linear vs quadratic elements)

"..quadratic elements more accurately approximate the solutions in msot cases."

Since I have more a structural background, I will stick to a structural view: It depends on the kinematics of interest. For instance, if there is contact involved, you'd want to stick to linear elements, and not quadratic ones.

*********************************************************
Are you new to this forum? If so, please read these FAQs:

http://www.eng-tips.com/faqs.cfm?fid=376
http://www.eng-tips.com/faqs.cfm?fid=1083

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources