Fatigue Testing and Simulation of Hi-Lock Bolted Single Shear Lap Joints

There are many parts of the aircraft with Hi-Lock bolted lap structures, such as wings and tails. The joints are subjected to alternating loads during the service of the aircraft, and the main failure form is fatigue failure. Taking the Hi-locking bolt single shear lap joint as the research object, the factors affecting the fatigue life of the single shear lap joint are investigated from both test and finite element analysis. Firstly, the fatigue test of the single shear joint of Hi-Lock bolt is conducted to obtain crack initiation location, fatigue life and the mechanical property parameters needed for simulation; secondly, the three-dimensional solid modeling and finite element analysis of the test specimen are carried out based on ABAQUS, and multiple influencing factors, such as two types of interference and clearance fits, load level, interference sizes, preload magnitude, etc., are studied on the fatigue life of the shear joint structure. The results of the finite element analysis show that the interference fit at low load is good for the improvement of the joint life, and the optimal interference size is below 2%; the high preload level applied is advantageous to obtain a higher life.