Abstract
In the present study, the interaction of two non-coplanar cracks and their growth behavior in round bars was investigated using the superposition finite element method (s-version FEM, S-FEM) and a number of fatigue fracture criteria. The S-FEM, in the frame of finite element method, is a global-local overlaying method. The interactions of two static cracks were analyzed by changing the relative distance between the cracks and the crack sizes. Simulations of the experimental conditions were then performed. The fatigue crack growth simulations were based on linear elastic fracture mechanics. The crack opening level was analyzed by a single elastic-plastic analysis and then integrated into the simulation while taking plasticity-induced crack closure into consideration. The simulation results were then compared to the experimental results, which were found to be in sufficient agreement. Finally, the variation of the stress intensity factor due to the interaction of two propagating cracks was investigated.
