General perturbation solution
- John Raymond Willis (University of Cambridge, Department of Applied Mathematics and Theoretical Physics, United Kingdom)
Abstract
A solution for a general 3D dynamic perturbation of a crack which, when unperturbed, propagates at uniform speed in the plane $x_3 = 0 $, so that, at time t, it occupies the surface $$ \left\{ x :-\infty < x_1 < Vt , -\infty < x_2 < \infty , x_3 =0 \right\} $$ was developed in recent years by Willis and Movchan. When coupled with a fracture criterion, it permits the study of the dynamic stability of the propagating crack. This has so far provided explicit confirmation of the existence of a "crack front wave", which is an in-plane disturbance of the crack front, which propagates along it without attenuation or dispersion. Also, more recently, it has been employed in its 2D specialisation to study the stability of the crack to out-of-plane disturbance. An outline of the general perturbation solution will be presented and both of these applications will be described.