Ansys Mechanical, convergence on holes in volumic

[Pouchel]

Hi everybody,

I'm using Ansys Mechanical quite often but so far I'm unable to reach convergence when there are holes. In my volumic model, I generally use a fixed support condition on the hole's inside walls and there are forces somewhere else on the part.

In general, the more refined the mesh is, the more stress there is. At the end the stress concentration is located on a ridiculously small area, but it is still there !

I've tried to use mesh refinements, and also to to a more realistic chamfer around the hole edges, but I got nothing.

Does some of you have tips to reach convergence ? By the way I surprizingly didn't find any papers related to that rather common problem.

Cheers
Charles

 

[hanxi]

Pouchel:

Good day.
Your case might be an example of Singularity problem.
Does your loading applied on a single node only? Have you tried distributing it on a set of nodes, say distribute the point load to 6 or 8 nodes (just an example).
Maybe it can help you to eliminate non-convergence problem.

Cheers.

 

[Pouchel]

Hi Hanxi,

Thanks for your answer.
In general for my problem the loads are applied on a surface. Therefore it is applied on multiple nodes. That is indeed the same for my fixed support.
Correct me if I'm wrong but I don't think that it is possible to apply a force on a specific node of the mesh in Ansys Mechanical. That make it different from the other EF software, but it's annoying for two reasons:
- Convergence problems like mine
- You must have a geometry to apply a load or a force, so you need to have for example a hole, which complicates the model

Charles