Fatigue Analysis of Spot-Welded Automobile Components Considering Fatigue Damage-Induced Stiffness Degradation in Time and Frequency Domains

초록

In this study, fatigue analysis was performed on a multi-point spot-welded outrigger structure utilized in an automobile engine room, where stiffness degradation from accumulated fatigue damage were considered. The S-N curve was obtained through a fatigue test on a single-point tensile-shear spot-welded specimen under constant amplitude load and finite element analysis based on the Rupp/LBF model. Fatigue analyses were performed in the time and frequency domains on the spot-welded outrigger structure, where changes in the local stress distribution and transfer function due to accumulated fatigue damage to the welding points were considered. Based on these results, it can be stated that the fatigue life of multi-point spot-welded structure under random loading should be evaluated considering the stiffness changes due to accumulated fatigue damage under the frequency domain.

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