Fastener fatigue fracture analysis and life prediction of composite connection structure

Abstract

According to the two failure mechanisms of fatigue fracture of fasteners, the fatigue damage evolution equation of microcrack initiation and propagation of fasteners is proposed, and the crack initiation life and crack propagation life models are deduced. After superposition, the fatigue model of fastener fracture failure is obtained. Based on the fatigue test results, two widely used fatigue life models (exponential and power functions) are compared. The results show that the exponential type and power function type only fit the test data without considering the different failure modes of the structure. Based on the failure mechanism, the fitting results of the model are in good agreement with the experimental results, and have great reference value in the design of fatigue structure.