航空发动机转子螺栓连接预紧力散差分析

Analyses of preload variations in aeroengine rotor bolted connections

螺栓连接预紧力的一致性对于保障航空发动机转子的安全运行有重要作用。该文针对航空发动机转子零部件的法兰止口典型连接结构的螺栓紧固控制问题,提出了含收口自锁力矩的扭拉关系修正模型,分析了收口自锁力矩衰减引入的偏差项的影响;并设计了工艺差异条件,搭建模拟试验环境开展了试验研究。结果表明:收口自锁力矩会因收口螺母的重复使用而发生衰减,从而对预紧力转化造成影响;不同润滑方式对预紧力转化有较大影响;随紧固件重复使用次数的增加,预紧力呈一定趋势变化,不同润滑方式下,预紧力变化趋势存在显著差异;不同批次螺栓也存在差异。该研究揭示了影响航空发动机转子螺栓连接预紧力一致性的关键要素,并对各要素引起的预紧力散度进行了精确评估,为下一步优化工艺方案提供了参考依据。

The preload consistency of bolted connections plays an important role in ensuring the safety operation of aeroengine rotors. A model was developed here for the torsional tension relationship with a self-locking torque of closing to improve bolt tightening control of flanged joints of aeroengine rotor assemblies. The model was used to investigate the influence of changes introduced by the self-locking torque attenuation for various processing conditions. Tests were then used to verify the model. The results show that the remained self-locking torque is reduced by repeated use of the tightening nut resulting in some loss of the preload on the flange. In addition, the lubrication conditions greatly impact the preload. Also, repeated use of the tightening nuts changes the preload along a known trend and different batches of bolts have different preloads. This study shows the key factors affecting the consistency of preloads of aeroengine rotor bolted connections and how to accurately evaluate the preload variations caused by each factor as a reference for optimizing the bolt processing.