Global-local finite element models for calculating fracture parameters

The finite element iterative method (FEIM) is applied to two types of problems for the evaluation of fracture parameters in laminated composite plates. The FEIM is first used to evaluate the order of power-type singularities and the angular variation in the displacement components near the crack tip at an interface between two dissimilar materials. Next, a numerically enriched global-local finite element is formulated that incorporates the asymptotic singular behavior as calculated by the FEIM in the assumed form of the displacements for calculating stress intensity factors. Examples of both approaches yield results that agree very well with existing analytic solutions.