The problem of an interface crack between dissimilar piezoelectric layers under mechanical and electrical impacts is formulated by using integral transform and Cauchy singular integral equation methods. The dynamic stress intensity factor and dynamic energy release rate (DERR) are determined through use of the obtained solutions and the effects of the loading ratio, the geometry of crack configuration and the combination of material parameters on the above two quantities are discussed. The numerical calculations indicate that the electrical load can promote or retard the crack growth depending on its magnitude, direction and the existence of the mechanical load and that with the increase of the value of ratio of two material parameters, some material parameters will inhibit the crack growth. On the other hand, some material parameters play the contrary roles. In addition, the geometry of the crack configuration has the significant effects on the DERR. Finally the results are compared with those obtained in a previous investigation.

Some closed-form equations for the coupling problem of buckling and growth of circular delamination are derived by recourse to the moving boundary variational principle The axisymmetric buckling of a circular delamination subjected to an equal bi-axial compression is analysed by using high-order perturbation expansion The axisymmetric buckled delamination has the following properties: under a certain residual pressure, there exist two characteristic radii, namely the critical radius Rc and growing radius Rg; for a certain interface toughness, the blister has three configuration of stationary, stable growth and unstable growth with increasing the loads Under a higher edge thrust, the nonaxisymmetric secondary buckling will occur on the base of axisymmetric buckling and then the toughness and the driving force of the interface crack will be different along the delamination front. So the growth of circular delamination will not be self-similar. Without any assumption regarding the delamination front, the cogfigurations of the blister with several nonaxisymmetric buckling modes n=2, 3, 6, 8, are simulated. The nonaxisymmetric growth process for the nonaxisymmetric buckling mode n=2 is simulated also under a sequence of loads.