Effect of Groove Geometry on Stress Distribution and Fatigue Life of TC4 Alloy

Abstract

In this study, the fatigue life prediction simulation of Chen et al. for TC4 titanium alloy components with surface defects is reconstructed and validated. When a scratch defect with a depth of 0.25 mm is introduced into the simulation, stress concentration occurs at the scratch root, and the predicted fatigue life reaches 3.2×10⁵ cycles, with an error of approximately 8% compared to the reference results. Based on this validation, the study is extended to investigate the influence of groove geometry on stress distribution and fatigue life using a dimensionless geometric parameter, i_AR. The results show that as i_AR​ increases, the maximum von Mises stress at the groove root decreases significantly, leading to a nonlinear increase in fatigue life. For i_AR < 2.7, the fatigue life remains lower than that of the initial component, whereas for values exceeding this threshold, the fatigue life is restored and significantly improved.