×
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

split surface singularities

split surface singularities

split surface singularities

(OP)
I'm having a problem with singularities at the boundary of split surfaces when a portion of the surface has a fixed BC applied to it.  As a simple example, if I have cantilevered arm which is supported by a wall over half the arm, I've split the surface in two, and applied a zero displacement in the y direction constraint to one half.  When I solve the model I find that there is a singularity along the split line, the stress goes up and up with each mesh refinement (in this case p-order).  Is there a better way to constrain the model?  Do I need to explore using some more advanced element, like a contact element or something similar?

As an alternative I can compute the reaction load ahead of time and apply it here, and then apply a displacement constraint to another portion of the model just to stabilize it and then check to be sure that any loads at that reaction are insignificant but I don't think this really models the problem as well.
 

RE: split surface singularities

So, your model is basically a diving board?

Well, if you're interested in the stress at the edge of the support, I'd suggest modeling the support. It's a good rule of thumb to apply your boundary conditions sufficiently far from your area of interest.

Honestly, though, if you're modeling a simple beam you can just look in Roarks and solve it by hand, can't you?

//signed//
Christopher K. Hubley
Mechanical Engineer
Sunpower Incorporated
Athens, Ohio
--
http://engineeringliberty.wordpress.com

RE: split surface singularities

(OP)
This is a simplified example, my model is much more complex.  It's actually a keyed assembly and I'm modeling the stresses in the keys.  I guess I can model the assembly and use contact elements, this would be the closest thing to reality but I'm trying to keep the size of my model down.  I was looking for some way I might model it using only the one part.

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