John Doyle
Ansys Employee
Are you expecting the concrete structure to develop cracks, but not catastrophically fail? Could it be possible that the nonconvergence you are experiencing is actually indicative of a physical instability leading to catastrophic failure? If that is the case, you will not be able to solve this beyond the point where the structure becomes unstable without adding more stabilization damping or solving with arc-length method. Or perhaps run this as a full transient analysis with damping.nYou mention that you ....modeled cracks by deleting specific number of elements... I assume you are using EKILL based on certain strain limits in /POST and executing restarts? If not, that would be the recommended approach as opposed to just deleting elements.nAlso, it looks like one of your plasticity material models is BISO or BKIN with near zero tangent stiffness. Is this associated the r-Bar? Are the elements associated with this material model going plastic also? If so, perhaps it would help to increase the tangent modulus to make this material model more forgiving in terms of convergence once plastic strains begin to develop.