On stress intensity factor computation from the quarter‐point element displacements

In conjunction with the quarter‐point element, a wide range of stress intensity factor computation techniques may be employed. Of these, the displacement correlation technique (DCT) and the quarter‐point displacement technique (QPDT) have been in common use. It has been suggested by various investigators that the DCT is more rational in formulation and should therefore be more accurate than the QPDT. However, published numerical studies provide conflicting results on the relative performance of either technique. To resolve this anomaly, this study provides a detailed investigation on the DCT and QPDT performance. On the basis of considering the second term in Westergaard's expression and supported by numerical experiments, it is concluded that the QPDT would generally perform better than the DCT.