A stress intensity factor estimation method for kinked crack

A method for estimating the stress intensity factors (SIFs) of kinked crack with finite kink length is presented. This method is based on an estimation expression which is derived by He et al. according to the work of Cotterell and Rice from the stress field series of the original (unkinked) crack tip to the second order by using weight function (WF). In order to increase the estimation accuracy for the kinked crack with finite kink length, the third order coefficients of the stress field series of the original crack tip are introduced into this expression and these parameters can be obtained by a fitting procedure. Application of this modified expression to the cases of singly-kinked, edge kinked and doubly-kinked cracks reveals a good approximation with the finite element (FE) results of SIFs and showed that the accuracy is increased.