A three-dimensional formula for determining stress intensity factors in finite element analysis of cracked bodies

Abstract A three-dimensional crack opening displacement correlation formula to calculate stress intensity factors is derived for 20-node collapsed isoparametric quarter-point elements. This formula has one order higher accuracy than the one usually used. Numerical results show that the new formula is insensitive to the variation of element size as compared to the old one for the finite element analysis of three-dimensional fracture problems.