Estimation of stress intensity factors from crack flank displacements

Abstract In the present numerical investigation, the efficacy of a recently proposed displacement based method for estimation of mixed mode (I/II) stress intensity factors of 2D configurations are demonstrated using additional benchmark examples. The proposed displacement based technique is simple, efficient and robust and can be used for the fatigue crack growth simulations. This technique uses the crack opening and crack sliding displacements obtained from the finite element analysis to determine the mode I, mode II and mixed mode (I/II) stress intensity factors (SIFs). This technique can provide the sign of the mode II stress intensity factors which enables it to be used for the fatigue crack growth simulations involving numerous computational steps. Quarter point elements (QPEs) are employed around the crack tip. Convergence of the present method is studied and the performance is assessed by comparing the extracted SIFs using other methods such as displacement extrapolation, J-integral and interaction integral techniques. The present study indicates that very accurate values of SIFs can be computed using the proposed technique and the accuracy of the SIF solutions are of the order of the path independent integrals