轮对通过磨耗后固定辙叉的试验研究及接触分析

Experimental Study and Contact Analysis of Fixed Frog After Wheel Set Passing Through Wear

为研究轨道车辆轮对通过磨耗后道岔固定辙叉的接触磨耗问题,搭建一种全尺寸轮对-固定辙叉试验台进行轮对通过辙叉的试验研究。并根据轮对过叉接触位置试验结果,选取5个典型接触位置建立轮对固定辙叉弹塑性接触模型,通过有限元仿真计算对轮叉间的接触斑与等效应力进行分析。由轮叉试验得出车辆轮对顺向(由心轨端驶向翼轨端)通过固定辙叉时,从距离理论尖端225 mm至237 mm位置处轮对与心轨翼轨同时接触;由有限元计算可知,辙叉心轨等效应力很大,易发生严重的磨耗;轮对过叉过程中,垂向位移会有明显的降低,且过叉速度越小,垂向位移相对降低值越大;轮对过叉方向不同,对辙叉最大冲击作用位置不同,但由于对中位置轮对与心轨的接触面积比翼轨小得多,故固定辙叉心轨磨耗比翼轨严重;有限元计算与试验研究结果相一致,为减缓辙叉磨耗提供有效试验方法。

In order to study the contact wear of the fixed frog of the turnout after the wheel set of the rail vehicle passes through the wear,a full-scale wheelset fixed frog test bench was built to test the wheelset passing through frog.According to the test results of wheelset crossing contact position,five typical contact positions were selected to establish the elastic-plastic contact model of wheelset fixed frog,Through the finite element simulation calculation,the contact spot and equivalent stress between the wheel and fork are analyzed.According to the wheel and fork test,when the vehicle wheelset passes through the fork in the forward direction(from the center rail end to the wing rail end),the wheel set contacts with the center rail wing rail at the same time from 225 mm to 237 mm away from the theoretical tip;From the finite element calculation,it can be seen that the equivalent stress of frog point rail is very large,which is easy to cause serious wear;In the process of wheelset crossing,the vertical displacement will decrease obviously,and the smaller the crossing speed is,the larger the relative decrease value of vertical displacement is;However,the contact area between the wheel set and the center rail is much smaller than that of the wing rail,so the wear of the center rail of the fixed frog is more serious than that of the wing rail;The finite element calculation is consistent with the experimental results,which provides an effective test method for reducing frog wear.