Dear all, question again:
I'm using XFEM to model crack propagation. There is convergence problem when I turned on NLGEOM, it works well if turned off NLGEOM. Moreover, if I change input elastic-plastic properties to linearly elastic properties, it works well even when NLGEOM is turned on. Anybody has some idea of this? I tried stabilization function at *step but failed to resolve this problem. Attached is my .inp file.
THANKS for any help.
RACHEL
| Attachment | Size |
|---|---|
| Job-1.txt | 152.31 KB |
Forums
MSG file reminds excessive
MSG file reminds excessive distorting at crack region, or sometimes reminds cracked elment might not be calculated correctly.
I'm stuck here for one
I'm stuck here for one week. Hope someone can help me get over this. Thanks a lot.
In reply to I'm stuck here for one by Rachel Clinton
Re: Abaqus XFEM crack propagation (NLGEOM not converge)
Your model is seeing excessive plastic deformation of the stiffer material.
There can be several solutions depending on what you're actually trying to simulate. For example:
1) Add cohesive elements between the interface of the two materials. The interface strength should be much lower than that of the bulk material.
2) Add more enriched elements around the crack zone, both above and below the interface. Note that the enrichment functions are based on linear elastic fracture mechanics and may not be correct when you have significant plastic deformation in the lower layer before the crack tip reaches it.
3) Use realistic material properties. This includes your failure criterion. A maximum principal stress criterion is not always appropriate.
-- Biswajit