75kg/m钢轨接头预留轨缝与接头热应力场分析

Analysis of Reserved Rail Gap and Thermal Stress Fields of 75kg/m Rail Joint

近期某干线铁路区间钢轨接头联结零件出现大量损坏的情况,为进一步探究故障原因,以线路普通接头为研究对象,以十余年轨温数据为基础,计算铺轨作业时预留轨缝、钢轨伸缩量,并且分析其在日常环境下的温度场分布及温度效应。依据轨道真实结构建立75 kg/m钢轨接头联结零件有限元温度场模型,分析不同工况下温度云图,并总结其分布规律。研究发现:该地区15 a内,各月预留轨缝平均值相差不大;对于普通钢轨接头,在螺栓中部、钢轨扣压部分、鱼尾板螺栓孔位置产生应力集中;受螺栓预紧力影响,钢轨接头应力集中点最大点在螺栓中部,且受预紧力影响较大;接头联结螺栓预紧力对钢轨温度应力影响比扣件更为明显;这些研究成果为今后养护维修工作提供理论支持。

To explore the causes of the appearance of a large amount of damage in the rail joints of some main trunk railway in recent years, in this paper, the common line connector is taken as the re- search object to calculate the reserved rail gap as well as the the rail expansion, and analyze the tempera- ture distribution and temperature effect in the daily environment based on the temperature data of ten years. The finite element model was established of temperature field of 75 kg/m rail joint connection parts according to the real structure of track to analyze the temperature contour in different conditions, and summarize its regularities of distribution. The study found that： Within 15 years in this region, the average of reserved rail gap was little changed by month; For the common rail joint, the middle bolt, rail buckling part and position of fishbolt hole would create a stress concentration; Because of the bolt pre-tightening force, the maximum point of the rail joint stress concentration was in the middle of the bolt, and was influenced obviously by the bolt pretightening force;The effect of the bolt pretightening force on the temperature Stress of the rail was more obvious than that of the fastener. These research sults may provide theoretical support for the maintenance and repair work in the future.