Accurate Estimation of Mixed-Mode Stress Intensity Factors Using Crack Flank Displacements

Abstract

Accurate estimation of mixed-mode stress intensity factors is essential for the fracture and fatigue studies of structural components. A recently proposed displacement-based method utilizing the nodal values of crack opening and crack sliding displacements for the estimation of stress intensity factors is discussed in this work. Convergence characteristics of the present method are studied using finite element meshes of various mesh densities. The performance analysis of the present method is carried out using various benchmark examples available in literature, and the SIF solutions are compared with the commonly used techniques such as displacement extrapolation, interaction integral and J-integral techniques. The present method requires less computational efforts only than its path independent integral counterparts. Furthermore, unlike the other popular displacement method considered in this study, the present method also provides the sign of the mode II stress intensity factor. This enables the present method to be used for the fatigue crack growth simulations.