I am working on modeling fracture at a bi-material composite interface in Abaqus 6.14-5, and I need guidance on how to properly introduce Cohesive Zone Model (CZM) and Extended Finite Element Method (XFEM) in this context. My objective is to realistically capture interfacial debonding and crack propagation.

The difficulty I am facing is how to correctly assign the interaction step at the bi-material interface. In CZM, choosing and calibrating interface stiffness and fracture energy is non-trivial, and in XFEM, defining initiation and propagation laws at an interface is not straightforward. Moreover, Abaqus 6.14-5 seems to restrict simultaneous use of cohesive behavior and XFEM in the same model, which makes the choice of method critical.

My problem is: How can XFEM and CZM be assigned to a bi-material composite interface in Abaqus 6.14-5, and what is the most reliable way to capture interfacial debonding in such a system? Any suggestions, best practices, or stepwise guidance from those with prior experience would be greatly appreciated.