J-Integral and Crack Opening Displacement Fracture Criteria

Abstract

A number of investigators have proposed the mathematical formulation of elastostatic conservation laws as path independent integrals of some functionals of the elastic field over the bounding surface of a closed region. For notch problems, Rice [1] introduced the two-dimensional version of the conservation law, a path independent line integral, known as the J-integral. The present chapter is devoted to the theoretical foundation of the path independent J-integral and its use as a fracture criterion. The critical value of the opening of the crack faces near the crack tip is also introduced as a fracture criterion.