Abstract
Three-dimensional cracks in an infinite medium or semi-infinite medium are analyzed using the self-similar crack expansion (SSCE) method, in which the stress intensity factors at crack tips are determined by calculating the crack-opening displacements over the crack surface. Calculations show that this method yields very accurate results for stress intensity factors of cracks with various geometries. Based on the numerical calculation by the SSCE method, the effects by Poisson’s ratio of materials on stress intensity factors are discussed for cracks in an infinite medium and semi-infinite medium.