TIME-DEPENDENT RESPONSE OF AN INTERFACE CRACK BETWEEN DISSIMILAR VISCOELASTIC MEDIA1*

Abstract

ABSTRACT A general solution of an interface crack between dissimilar viscoelastic media subjected to a time-dependent antiplane load is considered in this work. A complex potential function is derived via a special technique of analytical continuation to satisfy the continuous condition along the interface. A Cauchy-type singular integral is applied to solve the crack problem. The interaction between a singularity and an interface crack is then found with the aid of the superposition principle. According to the Kelvin–Maxwell model used to simulate the viscoelastic properties, the time-dependent full field solution can be obtained in a straightforward manner. Some typical loading types and the effects of dissimilar viscoelastic media on the energy release rate at the interface crack are also discussed. The result shows that the energy release rate becomes over-responsive when the relaxation constant of the upper half-space is smaller than that of the lower half-space. *Communicated by K. K. Choi.