Strength degradation and damage mechanism of TA1 titanium alloy clinched joints under fatigue loading

A digital model for the strength degradation of titanium alloy clinched joints was established using strength degradation tests and a fatigue cumulative damage model. This model aims to investigate the strength degradation law and fatigue damage failure mechanism of titanium alloy clinched joints under fatigue loading. Fractured test specimens were scanned to analyse the fatigue damage failure mechanism by examining the evolution of fracture morphology under varying fatigue cyclic loading times. The results demonstrate that the power index degradation model accurately predicts the strength degradation of titanium alloy clinched joints. As the number of fatigue loading cycles increases, cleavage features emerge alongside fatigue cracks, leading to a gradual reduction in joint strength. Ultimately, the strength degradation power index model for titanium alloy clinched joints is verified by the test to have high accuracy in predicting residual strength.