How to Solve the Warning: "Jacobian of gamma function is equal to ZERO"

Rolando Ho

I am trying to use the viscoplastic model based on overstress.

For certain parameter combinations, when i run the forward homogenization simulations, i keep getting the warning: "Jacobian of gamma function is equal to ZERO".  The simulation freezes and cannot be solved.

Below are the screenshots of the parameters and simulation i am running. Only simulation 5 is being used for the forward homogenization. 

What does this mean? 

How should I adjust my parameters to avoid this warning?

 

 

Layup ID 2 corresponds to 11 90-degree plies with nominal thickness of 0.315mm.

Any help or suggestions is appreciated.