Stress intensity factors for cracks emanating from two-dimensional semicircular notches using the composition of SIF weight functions

This paper presents stress intensity factor (SIF) solutions for edge cracks emanating from semicircular notches using the composition of SIF weight functions. The method isolates and combines the geometrical influences defined by constitutive SIF weight functions to yield SIFs for semicircular notches in finite thickness bodies. Finite element analysis was employed to obtain the required stress distributions and to generate reference constitutive SIFs. Problems encountered with curve fitting high gradient stress distributions were addressed and a robust mathematical solution for these was formulated. The new SIF solutions were verified by comparison with published solutions showing a high degree of accuracy and reliability. The composition model was demonstrated to allow rapid generation of SIFs for mode I cracks in complex geometries where the relevant simple constitutive solutions are available. These new solutions expressed as SIF weight functions allow interpolation between the geometrical parameters for which they are valid and also to include the effect of complex stress distributions such as those due to residual stresses.