Differences in results between solid mesh and surface mesh

General Questions
1

Hi to All. I wanted to simulate 3 forces on reference points using Distributing Coupling on solid elements and rigid body links with surface elements. I applied distributing coupling to surface element on solid and rigid links on node set.
Here are the results.

Solid Element:

image
image1474×845 160 KB

Surface Element:

{21ECE329-B2E6-4C25-B65B-380C8C6943B9}
{21ECE329-B2E6-4C25-B65B-380C8C6943B9}1522×909 303 KB

Why there can be error in stress distribution in surface mesh? Or the solid mesh is wrong?

Normally If we apply concentrated force on Node sets we need to divide the total force by the number of nodes. In rigid link do we need to do this again?.

Kind Regards,
Deniz.

2
  1. Which type of distributing coupling ?
  2. Are both constraints applied only to the hole ?
  3. Forces are applied only to the reference node of rigid body or coupling constraint.
  4. Why don’t you try with a simple test model where you can compare both approaches with analytical solution ?
  5. Can you share the file ?
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3

1.Distributing in 6 DOF.
2.Constraint only applied to the holes separetly.
3.Forces applied to reference node with rigid body constraint. in the menu of constraints->rigid body.
4. I did it on simple plate and the difference in displacement around 0.x, works quite well in a simple case but the structure is complex.
5. Not now, maybe tomorrow morning I can share it.

thanks for you reply.

4

*COUPLING and *DISTRIBUTING keywords ? There’s also *DISTRIBUTING COUPLING:

Also, be careful when using rigid body constraints with shell elements - this typically leads to non-convergence in nonlinear analyses.

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