Implementation of a new algorithm for evaluating 3D fracture analysis

This paper presents a new method for calculating the elastic stress intensity factors for 3D structural components under complex loads and with complex geometry. To this end, a hybrid element formulation was developed where the hybrid element has its stiffness matrix corrected to exactly reflect the existence of the true 3D crack geometry within the element. To obtain the stiffness matrix of the hybrid element, this approach involves the combined use of the redundant force method together with the displacement field results arising from the finite element alternating technique (FEAT). This matrix was subsequently used together with a standard commercial finite element package to obtain the force field of the nodes. Finally, these forces were used to determine the stress intensity factors along the crack front. This procedure was validated by comparison with results available in the literature.