MoS_(2)涂层螺栓连接的摩擦界面失效机制研究

Study on Friction Interface Failure Mechanism of MoS_(2)Coating Bolted Connection

在螺栓表面进行MoS_(2)涂层涂覆处理可提高其减摩性能进而减缓磨损,但也导致螺栓连接时螺纹表面磨损机制更为复杂。通过仿真与实验研究探究MoS_(2)涂层螺栓连接的摩擦界面失效机制,通过ABAQUS仿真软件将MoS_(2)涂层引入螺栓连接结构有限元模型中,得到在不同预紧力和界面摩擦因数下涂层螺栓螺纹处的应力分布及相对滑移幅值,并通过实验验证模型的准确性。结果表明:增大预紧力有助于MoS_(2)涂层螺栓连接防松,但预紧力过大会使螺栓连接界面的应力应变增大进而产生塑性变形,导致螺栓连接的防松效果降低;增大界面摩擦因数将使得螺栓连接界面的应力应变增大,导致其磨损程度也相应增加,并且第一圈工作螺纹磨损程度最严重;螺栓表面有无涂覆MoS_(2)涂层的应力分布规律和相对滑移幅值变化趋势基本相同,且在螺纹牙底均出现应力集中现象;但涂覆MoS_(2)涂层后的应力值相对较小,且螺纹表面的磨损程度降低,其摩擦界面失效机制主要为疲劳磨损。

MoS_(2)coating on the bolt surface can improve its friction reduction performance and slow down wear,but it also leads to more complex thread surface wear mechanism during bolt connection.Simulation and experimental research was carried out to explore the friction interface failure mechanism of MoS_(2)coating bolted connection.The MoS_(2)coating was introduced into the finite element model of bolted connection structure by ABAQUS simulation software.The stress distribution and relative slip amplitude at the thread of the coated bolt under different preload and interfacial friction coefficients were obtained,and the accuracy of the model was verified by experiments.The results show that increasing the preloading force is helpful to prevent loosening of the bolted connection of MoS_(2)coating,but too much preloading force will increase the stress and strain at the interface of the bolted connection and produce plastic deformation,resulting in a decrease in the anti-loosening effect of the bolted connection.The increase of the interface friction coefficient will increase the stress and strain of the interface of bolted connection,resulting in the corresponding increase in the wear degree,and the first circle of working thread wear degree is the most serious.The stress distribution law and relative slip amplitude change trend of bolt surface with or without MoS_(2)coating are basically the same,and the stress concentration phenomenon occurs at the bottom of thread teeth.However,the stress value is relatively small after MoS_(2)coating is applied,and the wear degree of thread surface is reduced.The failure mechanism of friction interface is mainly fatigue wear.