Crack-tip Caustics at a bi-Material Interface

The size and the shape of crack-tip caustics, at a bi-material interface, under static load, are studied. When the crack-tip, which is perpendicular to interface, is at the interface of the bi-material, the caustic depends on the properties of the two materials. Thus, the caustic is divided into two branches. The size of the two branches of the caustic mainly depends on the elastic modulus and Poisson's ratios of the two materials. This revised version was published online in July 2006 with corrections to the Cover Date.