Quantitative Identification and Prediction of 5182 Aluminum Alloy Clinched Joint Fatigue Life

ABSTRACT Clinching has emerged as a key research area in lightweight automotive design. A single‐lap clinched joint of 5182 aluminum alloy was selected as the subject of this study. A dynamic response test platform was developed to conduct fatigue–dynamic response tests on clinched joints. The rate of change in the natural frequency characterizes the stages of fatigue failure, and a life cycle prediction model for clinched joints was established. The results indicate significant changes in the 14th‐order natural frequency under high and medium loads, whereas the ninth‐order frequency changes significantly at low loads. The crack propagation rate was the highest at the medium load level, and the natural frequency change remained stable for the first 66% of its lifespan, with significant changes following crack initiation. The proposed prediction model quantitatively identifies the real‐time service state of a clinched joint and predicts its fatigue life.