脉冲电流作用下高铁接触网吊弦线拉伸试验探究

Investigation on Tensile Experiments of High-speed Rail Catenary Suspension String under Pulse Current

吊弦是电力传动机车接触网的重要组成部分,是高铁运行过程中必不可少的零部件之一。吊弦线在列车运行时容易发生断丝、断股或中间位置断裂,对机车稳定运行造成严重阻碍,因此通过脉冲电流辅助拉伸破坏实验对整体载流吊弦线工作状态下的抗拉强度和应力变化进行研究具有重要的意义。试验发现,拉伸前电流预处理会增大吊弦线的塑性,减小吊弦线抗拉强度和最大应力;电流辅助拉伸时,吊弦线中最大应力和抗拉强度随着电流增大而减小;电流相同而预处理时间不同时,吊弦线中的最大应力随着预处理时间的增长而减小。试验结果验证了铜镁合金材料的电致塑性效应理论,为高铁吊弦实际应用过程提供参考。

The suspension string is an important part of the electric transmission locomotive contact network and one of the indispensable parts in the operation of the high-speed railway.When the train is running,it is prone to breakage,broken strands or intermediate position breakage,which is a serious obstacle to the stable operation of the locomotive.Therefore,it is of great significance to study the tensile strength and stress changes under the working condition of the whole current-carrying suspension string by pulse current-assisted tensile failure test.It is found that the pre-stretching current pretreatment will increase the plasticity of the hanging string and reduce the tensile strength and maximum stress of the hanging string.In current-assisted stretching,the maximum stress in the hoisting string decreases with increasing current without pretreatment.The current is the same and the pretreatment time is different,the maximum stress in the hanging string decreases as the pretreatment time increases.The experimental results verify the electro-plastic effect theory of copper-magnesium alloy materials,and provide reference for the practical application process of high-speed rail suspension strings.