ON PERTURBATIONS OF PLANE CRACKS

Asymptotic analysis is presented for elasticity problems concerning ou t-of-plane perturbations of plane cracks. Some of the subtleties are f irst illustrated through consideration of two-dimensional problems; we derive formulae that generalize slightly those already available. Sol ution of the more difficult three-dimensional problem is facilitated t hrough novel use of an integral identity. The asymptotic formulae that are developed for the stress intensity factors are more flexible than those available previously, in that no special system of coordinates based on the perturbed crack edge is employed. (C) 1998 Elsevier Scien ce Ltd. All rights reserved.