Interfacial fracture analysis for heterogeneous materials based on phase field model

Simulating crack initiation/propagation in heterogeneous materials has long been a challenge due to their complex topology and the complicated interactions between each phase. In order to address this task, an interfacial debonding phase field model is established for interfacial fracture behavior of highly heterogeneous solids in this work. Inspired by the phase field framework, a discrete interface is transformed into a smeared interface using interface phase field. The developed model has the following novelties: (1) interface properties are smeared such that singularity of material property can be eliminated; (2) due to the interaction between characteristic length scale parameters of the interface and the crack, critical energy release rate of interface is regularized; and (3) it can predict complex cracking phenomena such as multiple crack initiation, merging and branching. Particularly, the proposed model is validated experimentally and numerically. With the proposed model, influence of interface properties such as Young's modulus and critical energy release rate on fracture behavior is studied in detail. The proposed model is potential in predicting interfacial debonding and the crack kinking path in complicated quasi-brittle heterogeneous materials.