Mesh convergence - How to do it

Mods FEM
1

I have drawn a structure in freecad and I would like to do a mesh convergence analysis.
How do I do that?

Thanks!

2
  1. Select the initial mesh size
  2. Run the analysis and examine the results, find hot spots
  3. Refine the mesh, possibly locally (around hot spots) and rerun the analysis
  4. Compare the new results (maximum displacements and stresses) with the previous ones and calculate the difference. If it’s higher than around 5%, repeat the last two steps. If it’s less than 5% you can consider the solution converged. A plot of mesh size vs maximum displacement/stress can be helpful to visualize convergence.

If after multiple repetitions and with good meshes you still can’t get the results to converge because the stresses keep increasing significantly then it can be a stress singularity often caused by sharp corners/edges. In such cases, you can add small fillets or include plasticity to see local yielding.