On the virtual crack extension method for calculating the derivatives of energy release rates for a 3D planar crack of arbitrary shape under mode-I loading

This paper generalizes the analytical virtual crack extension method presented by Lin and Abel [Int. J. Fract. 38 (1988) 217] by providing the energy release rates and their derivatives at all points along a three-dimensional (3D), planar crack front of arbitrary shape. It is shown that the local variation of curvature along the crack front and interaction between crack front perturbations at adjacent crack points must be considered to properly...