Fatigue strength evaluation on resistance spot welds of the vehicle body

摘要

This article evaluates the fatigue stress-fatigue life relationship of spot-welded structures in the vehicle body, considering the residual stress effect. When a vehicle travels on an actual road, the resistance spot welds of the vehicle structure are exposed to complex loadings. Because fatigue strength in the resistance spot weld of a vehicle body can be determined by residual stresses, joint geometry, and loading state during driving, actual loading state must be estimated with consideration of residual stresses. In this study, fatigue stress-fatigue life relationship derived from residual stress was obtained by thermoelastic, plastic, finite-element analysis. Applied loading in resistance spot weld of the vehicle body was calculated by dynamic analysis. Assumptions regarding fatigue life were based on proposed methods.