Geometry and material constraint effects on fracture resistance behavior of bi-material interfaces

Abstract

The finite element method based on GTN ductile damage mechanics model has been used to investigate the interaction effects of geometry and material constraints on fracture resistance behavior of bi-material interfaces. The geometry constraint is changed by changing the specimen width W, and the material constraint is changed by changing the work hardening mismatch. The main findings of this work are that the material constraint effect on fracture resistance of bi-material interfaces is related to geometry constraint, and there exists interaction between them. For lower geometry constraint, the material constraint effect on fracture resistance is insignificant. Under the condition of middle geometry constraint, the material constraint effect on fracture resistance is the most significant. With further increasing geometry constraint, the fracture resistance behavior of the interfaces is gradually dominated by the higher geometry constraint, and the material constraint effect becomes weaken. These results are analyzed by the stress triaxiality levels ahead of crack tips and crack path deviation.