Fatigue crack growth simulation of multiple surface cracks using dislocation dynamics

Abstract

This paper presents a numerical analysis method for surface crack problems based on the discrete dislocation dynamics (DDD) method. To satisfy the free surface boundary condition, the superposition principle is utilized. Virtual dislocation loops are placed at the outside of the body of interest to remove the dislocation singularity at the free surface. In this study, the DDD method for surface cracks was applied to the fatigue crack propagation problem for double surface cracks. First, fatigue crack growth analysis was performed for one surface crack, and the results were compared with the Newman-Raju solution to verify the validity of the numerical analysis method using the DDD method. Next, fatigue crack growth analysis was performed for double surface cracks and the results were compared with FEM.