A numerical analysis of interface damage effect on mechanical properties of composite materials

•A new damage model is proposed for interfaces in composite materials.•A 3D XFEM code is developed taking into account the interface damage.•The macroscopic behavior of composite is strongly affected by the interface damage.•The interface damage is influenced by the inclusion size.

Interfaces play an important role on macroscopic behaviors of composite materials. A number of studies have been devoted to analytical and numerical analyses of linear elastic interfaces. In this work, a new damage model is proposed to describe the progressive degradation of interfaces. The proposed model is implemented in the framework of extended finite element method. A series of numerical simulations performed. It is found that the interface damage induces a reduction of both macroscopic elastic stiffness and mechanical strength of composites. Further, related to the interface damage, we have also investigated the inclusion size effect on macroscopic behaviors of composites. It is found that the interface damage is enhanced by large size inclusions leading to a reduction of macroscopic damage threshold of materials.