Stress intensity factors in anisotropic bodies using singular isoparametric elements

A simple, yet accurate, approach for the determination of the stress intensity factors (SIFs) in three-dimensional (3-D) cracked anisotropic bodies modeled with quadratic isoparametric elements is presented. The main advantage of this formulation is that it does not require any code modification and the SIF calculation can be very easily performed as a simple post-processing of only four (in 2-D cases) nodal displacements. When tested against problems with known exact analytical solutions, it is found that the proposed approach yields very satisfactory results.