某型地铁车辆轴箱弹簧下盖螺栓断裂机理分析

Analysis of Bolt Fracture Mechanism on the Axle Box Spring Lower Cover of A Metro Vehicle

地铁车辆轴箱弹簧系统属于复杂的螺栓连接结构。通过有限元方法研究了在运用过程中其下盖螺栓断裂的机理。原结构U型底漆调整垫抗滑能力不足,在纵向载荷作用下发生滑动接触,导致螺栓承受较大交变弯矩,最终发生断裂。改进的圆型打砂调整垫显著提高了抗滑能力,改善了螺栓受载环境,大幅度降低了螺栓承受的弯矩载荷。结果表明:被紧固结构的接触状态直接影响紧固螺栓的使用寿命。

Metro axle box spring system is a kind of complex bolt connection structure.The mechanism of lower cover bolt fracture occurred during application is studied by using finite element method(FEM).Due to the insufficient anti-sliding ability of the original structure U-type primer adjustment pad,the sliding contact occurs under the action of longitudinal load,and the bolt is subjected to large alternating bending moment and eventually breaks.Modified round milled sand adjustment pad could significantly improve the anti-sliding ability and the bolt loading environment,reduce the bending moment load on the bolt.The results show that the contact state of the fastened structure directly affects the life span of the tightening bolt.