Cracks at interfaces—Atomistic versus continuum models

Sharp cracks with tips at interfaces in a bimaterial medium show a much richer variety of singularities in the stress fields near the tips as predicted by continuum linear elastic models than do similar cracks in a homogeneous elastic medium. The real or complex magnitudes of these singularities depend upon the ratio of the elastic constants of the two media as well as upon the angle between the crack and the interface. Problems incurred in comparing results of atomistic simulations of such cracks with the relevant continuum solutions are discussed.