Hi,

I am trying to model a simple yielding behavior of Al subjected to bending and/or tensile loads. I used, to start with, an elastic-perfectly plastic material model in ABAQUS with *Static option. As I dont know the exact material properties, the idea is to theoretically test different material yield points to assess the material failure pattern for a given load. The structure is subjected to load, and is not displacement controlled.

The problem: I am having convergence issues as I (artificially) reduce the yield stress below certain limit (~180 MPa).

Additional information : - I got a converged result for an Linearly Elastic material model - it gives me some idea of value of von-mises stress distribution (~300 MPa). now, when I assumed elastic-plastic model and yielding is around 200 MPa, the solution still converges, but it does not below a certain value of yield stress - say 180 MPa. I dont know why? For Sigma-Y = 180 Mpa, solution will abort around 97% of load, similarly, for 150 MPa - around 83% of load. What does it mean?

Any suggestions/solutions??

Thanks in advance.

Jay