Hello,

I have a model consisting of three components: Fibre (Isotropic), Interface (Cohesive Elements) and Matrix (Ductile Damage).

If I run the model without the ductile damge, it works fine (first picture) -> Interface fails

If I run the model without the interface, it works fine (second picture) -> Matrix fails

But when I run both together, the interface starts failing and failure is also initiated in the matrix but then it does not converge (third image): "Time increment required is less than the minimum specified".

I suspect that has something to do with the fact, that the matrix material starts failing at the cohesive interface.

Settings:

One part with different sections assigned to it

Units: Length[µm], Time [ms], Stress [GPa]

Periodic Boundary conditions

Solver: Unsymmetric (as recommended in the manual)

Minimum time step: E-25ms

Maximum time step: 10ms

NLGeom: On

Specific dissipated energy fraction: 0.0002

Max ratio of stabilization to strain energy: 0.05

Maximum degradation (matrix&interface): 0.99

I've spend many hours trying to find a solution but was not successful. Do any of you have a tip for me?

Kind regards

Mike