Investigation of near-tip displacement fields of a crack normal to and terminating at a bimaterial interface under mixed-mode loading

The displacement fields near the tip of a crack in a bimaterial joint under mixed-mode loading have been investigated by using a highly sensitive moiré interferometry technique. With a scheme adopted for data reduction, the study find that the near-tip displacements due respectively to opening and slipping loads are non-coupled and separable. The study on the parameters characteristic of the crack-tip deformation include: (1) the strength of stress singularity; (2) the angular distribution; and (3) the stress intensity factors KI and KII. The characteristic parameters determined experimentally are compared with the theoretical ones for the problem given by Zak and Williams [J. Appl. Mech. 30 (1963) 142], and Chen [Eng. Fract. Mech. 49 (4) (1994) 517].