What is the difference between combine (merge) and share topology?

- July 7, 2022 at 12:18 pm
  
  Balha
  Subscriber
  
  Ansys SpaceClaim
  I have two bodies to be welded together.
  First I run the analysis using the share topology, and then I combined the two bodies together and ran the analysis again.
  I get other results that are completely different (the equivalent stress with combined bodies is much less).
  can someone please explain the difference to me?
  Thank you
- July 7, 2022 at 5:55 pm
  
  peteroznewman
  Subscriber
  
  You can get similar stress results for a mesh based on Share topology and a mesh using a Merge to unite two bodies into one if you make sure the element size near the region of high stress is similar.
  It's likely your geometry includes a stress singularity such as a sharp interior corner. In that case, when the element at point of highest stress is half the size, the stress can roughly double. Measure the distance between two nodes at the point of high stress and see if the shorter distance is the mesh with the higher stress.
  Please insert some images of the two meshes with the peak stress contoured on them.