锥螺栓干涉连接对2024铝合金接头疲劳性能的影响

By simulating the taper-bolts installation and applying process of pre-tightening force preloading of 2024 aluminum alloy joints, fatigue life was predicted with the application of distal alternating load, fatigue tests were carried out to verity the simulation results, and fatigue fracture was analyzed. The results show that No. 2 hole of middle plate is the weak part of joint fatigue failure. With the increase of interference level, the stress concentration degree of No. 2 hole of middle plate is relieved. Fatigue tests verity that fatigue failure appears in No. 2 hole of middle plate. The trend of fatigue life obtained by simulation and test is basically same. With the interference increases, the fatigue life first increases then decreases, and reaches the maximum with interference level of 4, which is two times of clearance fit. The suggested interference level for engineering is 3 and 4. The macro fracture is multi-source fracture. Interference fit can strengthen the hole wall and inhibite crack initiation. Microfracture is quasi cleavage fracture with a small amount of equiaxed dimples and river pattern.