Adaptive remeshing with XFEM?

[Ply22]

Hey guys, i am currently simulating a crack propagation problem with XFEM in ABAQUS. For the mesh i want to use an adaptive remeshing process to generate the optimum mesh for this problem. I was wondering if there is a possibility in Abaqus to do an adaptive remeshing around the crack tip during the simulation process itself. I know there is an adaptive remeshing tool integrated in ABAQUS, but i tried it and it doesn't seem to work in conjunction with XFEM enriched elements.
I would be glad about any help.

 

[FEA way]

According to Abaqus documentation (chapter: "Modeling discontinuities as an enriched feature using the extended finite element method") it’s not possible to use XFEM woth adaptive remeshing. But remeshing shouldn’t be necessary in this case because XFEM is mesh-independent method.

 

[Ply22]

Okay thanks for the tip. I thought an adaptive remeshing could help with convergence problems though, that was my initial motivation. But you're saying it wouldn't make any difference?

 

[FEA way]

If you have convergence issues in analysis with XFEM then there are other ways to handle this. Try automatic stabilization, include damage stabilization in material definition and modify default solution controls (set discontinuous analysis and increase I_A to 20).

 

[DrZoidberWoop]

I always thought XFEM was heavily mesh dependent because of the activation criterion being based on the stress and strain values of the enriched elements. For instance, I've had plenty of spurious results where multiple cracks initiated simultaneously in adjacent elements because the mesh was too fine.

 

[FEA way]

Indeed this mesh independence of XFEM applies more to the fact that mesh doesn’t have to match the geometric discontinuities. Best results are achieved when initial flaw is included in the model.

 

[Ply22]

Yes, i got the same oroblem with multiple cracks when the mesh is too fine. That was one of the reasons why i was wondering if there is such a thing as adaptive remeshing with XFEM enriched elements. But i guess there is not, so i will do a mesh study an check which mesh works the best. Thank you for your answers!