Damage behavior investigation of CFRP/Ti bolted joint during interference fit bolt dynamic installation progress

摘要

Interference fit can significantly enhance the tensile and fatigue strength of CFRP/Ti bolted joints, however, the damage can occur during interference fit bolt installation progress. Therefore, an experimental study was conducted to understand damage behaviors of the joint during the interference fit bolt installation progress using dynamic installation method based on electromagnetic dynamic force. The installation resistance was evaluated and the damage mechanism was discussed. Moreover, the influence of interference size on damage behaviors was also studied. The test results demonstrated that the installation resistance exhibited two typical stages and mainly generated by Ti plate, which agreed with theoretical analysis. Damage modes of the joint were dominated by CFRP damage and significantly influenced by interference size. The internal damage mainly occurred in the entrance and the exit of the hole in CFRP, especially, the first ply along the installation direction was the most critical ply, on which a typical damage ring was observed. The dynamic installation method can reduce the damage and the layer deflection of CFRP, which is suggested to be used to improve joint designs.