Discussions on weight functions and stress intensity factors for radial crack(s) emanating from a circular hole in an infinite plate

A thorough verification is made for two recently developed weight functions (WFs) by Jin et al. for a single crack and two symmetric radial cracks emanating from a circular hole in an infinite plate. Through comparisons with other WFs (or Green's functions), it is found that the Jin et al.'s WFs are in marked disagreement to those of Shivakumar-Forman, Newman and Wu-Carlsson, especially for the single crack geometry. Significant disagreements in SIFs obtained by using Jin et al.'s WFs are also found for loadings which are much different from the reference load cases used for deriving their WFs. Possible sources for the poor accuracy of Jin et al.'s WFs are discussed and identified, including limitation of the two-reference-load-cases-based WF approach, choice of reference load cases and sensitivity of these WFs to the inaccuracy of the two reference SIF-solutions. By using a the Wu-Carlsson unified WF approach with crack opening displacement as an additional condition, new analytical WFs for the two hole-edge crack geometries are developed and verified, and further used to derive closed form SIF-expressions for several basic crack line stresses. The new analytical WFs will facilitate more accurate fatigue and fracture analyses for arbitrarily loaded hole-edge crack(s) in an infinite plate.