I am modeling the debonding between concrete and CFRP subjected to tangential loading using ANSYS Workbench, I used (CZM/VCCT)  techniques to model the debonding. as you know with workbench you can't choose the element type directly. you have to insert commands for Solid65. or use the default solid186.

I already tried the following to get my model to converge for solid65 in workbench:

1- Refining the mesh.

2- Reducing the normal stiffness of the contact region

3- Use newton Raphson residuals.

4- Playing with steps and sub-steps (applying displacement in small intervals).

Any help or suggestions will be highly appreciated.

Thanks in advance.