ON STATIONARY AND MOVING INTERFACE CRACKS WITH FRICTIONLESS CONTACT IN ANISOTROPIC BIMATERIALS

The asymptotic structure of near-tip fields around stationary and stea dily growing interface cracks, with frictionless crack surface contact , and in anisotropic bimaterials, is analysed with the method of analy tic continuation, and a complete representation of the asymptotic fiel ds is obtained in terms of arbitrary entire functions. It is shown tha t when the symmetry, if any, and orientation of the anisotropic bimate rial is such that the in-plane and out-of-plane deformations can be se parated from each other, the in-plane crack-tip fields will have a non -oscillatory, inverse-squared-root type stress singularity, with angul ar variations clearly resembling those for a classical mode II problem when the bimaterial is orthotropic. However, when the two types of de formations are not separable, it is found that an oscillatory singular ity different than that of the counterpart open-crack problem may exis t at the crack tip for the now coupled in-plane and out-of-plane defor mation. In general, a substantial part of the non-singular higher-orde r terms of the crack-tip fields will have forms that are identical to those for the counterpart open-crack problem, which give rise to fully continuous displacement components and zero tractions along the crack surfaces as well as the material interface.