Fatigue test and analysis of Hi-Lock bolt lap joint structure

Abstract

Abstract Hi-Lock bolt lap joint structure is widely used in aircraft, such as wings, tails and etc. During the service of an aircraft, the joints are subjected to variable loading, which may usually tend to fatigue failure. The single-shear lap joint with four Hi-Lock bolts is taken as the research object. The static tensile test and fatigue test of the Hi-lock bolt lap joint structure are conducted. The macroscopic and microscopic fracture analysis were carried out. It is found that the crack source is located on the joint surface of the two plates, which is on the longitudinal direction away from the edge of the hole, but not on the edge of the connection plate. The results also show that there is no significant difference between the effect of clearance and interference fit on the fatigue life of the lap joint structure under high load conditions.