Stress Intensity Factor Analysis of an Interface Crack between Dissimilar Materials under Thermal Stress Condition by Virtual Crack Extension Method.

Abstract

A new method is presented for stress intensity factor analysis of interface crack problems under thermal stress conditions. The virtual crack extension method, which is used with the finite element method, is a powerful tool for estimation of the energy release rate. The virtual crack extension method is applied to stress intensity factor analyses of thermal interface crack problems. The energy release rate obtained by the virtual crack extension method is separated into individual stress intensity factors, K1 and KII, by the principle of superposition. The presented method is applied to several thermal stress interface crack problems. The results are compared with those obtained by the displacement and stress interpolation methods. It is found from these analyses that the present method gives very accurate results which are insensitive to the size of finite elements.