高速铁路弹条疲劳对其扣压力的影响

高速铁路弹条长期在循环荷载作用下工作,不可避免地出现疲劳,弹条的疲劳将对其扣压力产生影响。本文以WJ-7型扣件弹条为例,首先对弹条进行静力试验分析,运用应变电测法测量出弹条在不同的安装预紧力作用下其危险部位的等效应力大小,得出弹条较为合理的安装预紧力为25 kN;然后使用疲劳试验机对弹条施加3种循环荷载分析其扣压力的损失,并根据疲劳试验结果给出了不同循环荷载作用下弹条扣压力与弹条中圈位移间的关系式。

Influence of Spring Bar Fatigue on its Fastening Force for High Speed Railway

The spring bar of high speed railway works under the cyclic load for a long time,which inevitably leads to fatigue.The fatigue of spring bar will affect its fastening force.Taking the WJ-7 fastener spring bar as an example,the static test analysis of the spring bar was firstly carried out,the equivalent stress of the dangerous parts of the spring bar under different installation preload was measured by strain electrical measurement,and it is concluded that the reasonable installation preload of spring bar is 25 kN.Then,three kinds of cyclic loads were applied to the spring bar by fatigue testing machine to analyze the loss of fastening force.According to the fatigue test results,the relationship between the fastening force of spring bar and the ring displacement of spring bar under different cyclic loads was given.