目的 为了提高螺栓连接结构的可靠性，分析剪切激励下螺栓连接结构松动失效机理，并研究润滑脂对螺栓连接松动行为的影响。方法 基于自主设计的试验装置，开展了剪切激励下螺栓连接结构的松动试验，分析了两种润滑脂(MoS2润滑脂和锂基润滑脂)对螺栓连接结构松动行为的影响，试验结束后使用扫描电子显微镜分析螺纹表面的损伤情况。结果 在相同预紧力条件下，使用润滑脂的螺栓连接结构初始预紧力矩可降低30%~40%。螺栓连接结构所承受的剪切载荷存在门槛值，即当剪切载荷低于门槛值时，连接结构不会完全松动。在螺栓前三圈接触螺纹表面添加润滑脂(局部润滑)，门槛值降低;在螺栓全部接触螺纹表面均添加润滑脂(完全润滑)，门槛值进一步降低。当承受载荷幅值低于门槛值时，局部润滑有利于防松，螺栓连接结构的松动程度可降低20%以上。结论 螺纹接触界面的微观滑移和微动磨损是螺栓连接结构松动的主要原因，在螺纹接触界面添加润滑脂可有效减缓螺纹表面的微动磨损。

The work aims to improve the reliability of bolted joints by analyzing the self-loosening mechanisms of bolted joints subject to dynamic shear load and investigating the effect of lubricating grease on the self-loosening behaviour of bolted joints. Based on the self-designed experimental equipment, loosening tests were carried out to the bolted joints under the shear load to analyze the effect of two lubricating greases (molybdenum disulfide grease and lithium grease) on the self-loosening behavior of bolted joints. After tests, the damage of the first engaged thread was analyzed by scanning electron microscopy (SEM). The initial tightening torque of the bolted joints with lubricating grease was reduced by 30%~40% under the same preload. There was a critical value of shear load on bolted joints. When the amplitude of shear load was below a critical value, complete loosening would not occur. The critical value decreased when the first three engaged thread surfaces of bolts were lubricated (local lubrication), and then further decreased when all of the engaged thread surfaces of bolts were lubricated (complete lubrication). When the amplitude of shear load was smaller than the critical value, local lubrication was effective to improve the anti-loosening performance of bolted joints, and the loosening degree of the bolted joints was reduced by more than 20%. Microslip and fretting wear between the contact threads are the main loosening mechanisms of bolted joints. Adding lubricating grease at the thread interface can effectively reduce the fretting wear on the thread surface.