Abstract
First, the separated dynamic J integral and the separated dynamic energy release rate useful for dynamic interfacial fracture mechanics are presented. The path independent separated dynamic J integrals have the physical significance of energy flows into an interfacial crack tip from adjacent individual material sides. Second, new definitions of the stress intensity factors for dynamically propagating interface cracks are derived, which are consistent with the dynamic stress intensity factors for cracks in homogeneous materials. Based on this, an explicit relationship between the dynamic J integral and the stress intensity factors is also derived. Then, using this relation, to extract mixed-mode stress intensity factors in dynamic interfacial crack problems, the component separation method is developed. This method is more advantageous than the M1 integral method often used for interfacial crack problems, since the present method requires no auxiliary solution field that is sometimes not possible to construct. Finally, to demonstrate the applicability of the separated dynamic J integral and the component separation method, interfacial cracks subject to impact loading as well as dynamically propagating interfacial cracks are solved using a moving finite element method. Several useful points are elucidated from the numerical simulation results.
