STRAIN ENERGY RELEASE RATE FOR A CRACK UNDER COMPLEX LOADING

Abstract : This paper gives an expression for the energy release rate in an arbitrary direction for a crack subjected simultaneously to Mode I, Mode II and Mode III conditions. The energy release rate is computed using the elastic solution of a deflected crack, having a main branch and a propagation branch. The elastic solution for the anti-plane problem is easily obtained by use of complex variables. For the in-plane problem we use the limiting solution recently obtained. Using the critical energy release rate criterion, incipient paths of propagation as well as the fracture stresses of such a crack, were obtained from the maximum value of the energy release rate. Results are in close agreement with a few experimental results available in the literature. The energy release rate, in parametric form, can be used for any crack subjected to Modes I, II and III loading conditions. (Author)