SimScale CAE Forum

Problems with a Convergence Study


#1

Hello, I’m trying to do a convergence study using a small model created using On-Shape. I created a point on a surface and studied the stress under different meshing conditions. But somehow the results never seem to match or look similar.


#2

Hi @atimotors!

Could you share the project with us please? Will have a closer look and see what might cause the issue.

Best,

Jousef


#3

Hello, @jousefm

Here is the project link: https://www.simscale.com/workbench?publiclink=3cfe4ec5-30ec-469a-96af-896b95dcfba2

Thanks


#5

Hello @atimotors,
the fact that you don’t see a convergence in your data is related to the way how you do the convergence study by only looking at the total number of DOFs but at the same time having non-uniform mesh refinements.

I did a new convergence study of your problem using three distinct meshing approaches:

  1. first order without refinements
  2. second order without refinements
  3. second order with local refinements on the fillets (where the high smax appears):

refinement_fillets

Here the results:

From the results you can see that the mid point stress is converged pretty early whereas the max stress in the model does only converge for a very high nomber of DOFs. This is due to a highly localized stress concentration (see screen shot) where the max stress happens.

Hope this clears your doubts!

Ah, and here the link to the project as reference: https://www.simscale.com/projects/rszoeke/convergence_study/

Best,
Richard


#6

Thank you for the study!