Fracture prediction of hole patterns with multiple cracks using the finite element method

This research develops new techniques for solving fracture problems involving multiple cracks. The hypothesis is that, for structures with interconnected load paths, fatigue loading does not have to result in failure. Each computer model consists of a plate with notches (flaws) subjected to biaxial tension, which creates a fracture hazard. The original prototype structure is a steel plate with a symmetrical diamond pattern of circular holes commonly used in pressure vessel design. The computer models simulate this plate exactly. Results from the literature corroborated the computer models. Prediction of stress intensity factors and flaw shape factors was within negligible error. In addition, test cases produced crack trajectories that were qualitatively correct.