Crack front waves in an anisotropic medium

A crack front wave is a dynamic perturbation of the edge of an extending crack; it propagates along the edge without attenuation and thus implies absence of radiation of energy from the perturbation into the bulk of the medium. The existence of such a wave was recognised about a decade ago, when the elastic medium through which the crack propagates is isotropic. Here, the corresponding analysis is presented for a crack under Mode I loading extending on a plane of symmetry of an otherwise general anisotropic elastic medium.