Stability analysis of nut coefficient of aero-engine rotor connection bolt

Aiming at the problem that it is difficult to control the preload consistency of aero-engine rotor bolts, the bolt tightening experiment was carried out on the fastener torsion tension testing machine, and the influence of controllable factors such as bolt usage times and tightening speed on the nut coefficient was analyzed. The experiment results show that the nut coefficient decreases with the increase of the torque in the process of bolt tightening; the average value of the final nut coefficient at the tightening speed of 20 r/min is higher than that of 8 r/min and 50 r/min, and the mean square deviation decreases with the increase of tightening times; the nut coefficient of the final tightening is the largest at the first tightening, then decreases rapidly at the second tightening, and then tends to be stable. Therefore, the tightening times should be distinguished and the tightening speed should be restricted in order to control the consistency of bolt preload.