Maximum Interference Fit Size of Hi-lock Bolted Joints

Interference fit is an effective process method for improving fatigue life of bolted joints.The finite element model(FEM) is developed and the process of oversized titanium alloy hi-lock bolt pressed into a hole is simulated.At different interference fit size,the maximum stress values on hi-lock bolt and hole wall and the stress distribution characteristics of lap plates are presented,the simulation result shows that maximum interference fit size is 2.0% for hi-lock bolt static installation,then the law of plastic zone size and protuberance size on lap plates with the interference fit size increasing are also investigated.Base on the numerical simulation,the experimental test of hi-lock bolt installation is done,by the comparison of test result and simulation prediction on squeeze force and protuberance height at hole exit,the numerical simulation is validated.The reason of cracking or latency crack at hole exit of specimen having the concavity around holes is studies,and the experimental protuberance scope size effected on the fatigue fretting of bolted joints is also analyzed,which shows that the interference-fit size should be less than 2.0%.