×
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

Convergence anf mesh refinement

Convergence anf mesh refinement

Convergence anf mesh refinement

(OP)
Hello everybody,

I'am trying to create a model of a small connecting rod . It is like a dumbbell with hole at each end to install spherical rod bearing. The boundary conditions are axial load only.
I have created a 2D model on ansys workbench. The axial load is apply with a pressure on line. This pressure is applied to one half of the spherical bearing location. This structural analysis is linear and static.
My problem is when I solve the simulation with finer mesh, there is no convergence of Von mises stresses which increase dramatically as the mesh is refined.
So I have check the maximal principal stresses and shear stresses, and the shear stresses inscrease dramatically and the principal stresses converge.

May you help me to solve this problem of shear stress which increase ?

Thank you very much for your help,

Best Regards,

Mickael



RE: Convergence anf mesh refinement

Hi Mickael,

Have you looked at the location of the maximum stresses for each mesh? If they are located next to the spherical regions of your model it is possible that you have encountered a stress concentration. If you employ local refinement in these regions, the stress values should eventually converge. If the maximum stresses are observed next to a sharp corner or within the same location that you have applied a point load/constraint however, it is possible that you have encountered a singularity. Unfortunately these stresses will increase to infinity as you refine your mesh.

If you search this forum and google you will find a lot more details/discussion of these issues.

Good luck,
Dave

RE: Convergence anf mesh refinement

(OP)
Hi Dave,

Thank you for your response.
The maximum stress location is the same for each mesh: The nodes on the boundary between no displacement boundary condition nodes and nodes with axial load. I have tried to refine the mesh at this location but there is no convergence.

Thanks a lot!
Best Wishes!

Mickaël

RE: Convergence anf mesh refinement

Posting a screen shot of the high stress location would help a great deal (including loads, constraints, and geometry). However, you stated that, "maximum stress location is the same for each mesh: The nodes on the boundary between no displacement boundary condition nodes and nodes with axial load.". If I understand this correctly, then you're saying that the peak stress happens at the constraint. If so, then this is a singularity as well, since at this location you have an infinite discontinuity in the stiffness (from the Young's Modulus to the constraint, which has infinite stiffness).

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