Contact US

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!

*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

Contact boundaries and stress results averaging

Contact boundaries and stress results averaging

Contact boundaries and stress results averaging

Dear all,

I recently completed successfully a 3d connection problem where two steel plates are connected with a bolt and subjected to tension/bending. The question arises from the observation that the element stress results through the "extrapolation" option need to be "averaged" or remain "linear" depending on the contact boundary option. I explain:

With contact boundaries set to "Discrete" and "job results"-->"Element results" option set to "all points" then during post processing I need to "average" the stresses through the settings-->Extrapolation in order to see the correct results. To avoid this, "Element results" option has to be set to "centroid" from the "job results" menu. Then the correct stresses appear with the extrapolation set to "linear" (default setting, no intervention from the user).

With contact boundaries set to "Analytical" exactly the opposite happens: Element results are set to "all points" and the stresses appear correctly without "averaging". If the "centroid" option is active then the stresses have to be "averaged".

Does anyone know/guess why the contact boundaries affect the element stress results? As far as I understand in both cases the results are correct, however "averaging" is needed to have the results matching as explained above.

I sincerely hope that my question isn't a confusing one; should any additional info is needed please ask me to provide more details.
Thank you in advance for your kind assistance.

RE: Contact boundaries and stress results averaging

Further investigation showed that the problem described above was evident only when the model was subjected to a pure tensile load (single point force). There was no significant difference in stress results between discrete and analytical contact in other loading conditions (such as bending). Maybe it has to do with the contact detection options.

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! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close