A linear elastic finite element approach to fatigue life estimation for defect laden materials

Abstract

This work assumed that the stress-life behaviors of defect-laden materials converge at a certain low life cycle and attempted to estimate fatigue life by applying relative knock-downs to the endurance limit of a reference stress-life data. Linear elastic finite element analysis on small cracks initiated from defects was performed to evaluate the effect of defect size, aspect ratio, and location on endurance limit. While for internal defects size and shape are both influential, size and depth were found to be more important for surface defects. These findings were validated against the fatigue lives of laser powder bed fused Ti-6Al-4V specimens.