Estimates of the J-Integral for Elastic-Plastic Specimens in Large Scale Yielding

Abstract

A generalization of the area under the load-deflection curve method for estimating the J-integral in cracked elastic-plastic specimens in large scale yielding is proposed. The results of this method are compared to values of J from other theoretical techniques, all based on finite element calculations for plane strain cracked specimens. The new formulae are found to be reasonably accurate. In particular, the results for the compact tension specimen are superior to those obtained from the established Merkle-Corten formula. The technique could be extended to structures in service containing cracks, and then would have similarities to the reference stress method already used in high temperature design against creep.