The experimental investigation were conducted in order to study the dynamic strength of the mechanically fastened composite joints, involving interference-fit joints with blind bolt and sliding-fit joints with high lock bolt. The joint type of the specimens researched was single-bolt, double-lap, which was a standard test configuration in ASTM for composite joints. Experimental results showed that the fatigue performance of the blind bolted joint was better than that of the high-locking bolted joint. The fatigue life of the blind bolted joints was 10-100 times higher than that of the high-locking bolted joint under the same cyclic stress, and the limit fatigue strength of the blind bolted joints was over 50MPa higher than hat of the high-locking bolted joints.

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.