A path independent integral for the crack extension force of the circular arc crack

A path independent integral expression for the crack extension force of a t wo-dimensional circular are crack is presented. The integral expression, wh ich consists of a contour and an area integral, is derived from the princip le of virtual work. It is implemented into a FEM post-processing program an d the crack extension force is calculated for a circular are crack in a lin ear elastic material. Comparison with exact solutions by Cotterell and Rice [10] for the effective elastic stress intensity factor shows acceptable ac curacy for the numerical procedure used. (C) 2000 Elsevier Science Ltd. All rights reserved.