Extended finite element method for three-dimensional crack modelling

An extended nite element method (X-FEM) for three-dimensional crack modelling is described. A discontinuous function and the two-dimensional asymptotic crack-tip displacement elds are added to the nite element approximation to account for the crack using the notion of partition of unity. This enables the domain to be modelled by nite elements with no explicit meshing of the crack surfaces. Computational geometry issues associated with the representation of the crack and the enrichment of the nite element approximation are discussed. Stress intensity factors (SIFs) for planar three-dimensional cracks are presented, which are found to be in good agreement with benchmark solutions