三向载荷作用下铁路磨耗型车轮和钢轨的接触应力分析

The Interior Stress Distribution on Railway Worn Profile Wheel and Rail Under the Action of Three Directional Loading

本文用理论分析方法,并结合数值计算和光弹实验,分析了铁路磨耗型车轮与钢轨在三向载荷作用下内部的应力场分布,得到了一些重要结果。假设当两个接触面处于相对滑动的临界状态时,切向力与垂向力成正比。为了说明应力分布的情况并根据车轮与钢轨相接触的实际情况,假设切向力与垂向力的比例数值(即摩擦系数)为1/3。用叠加方法计算出了在垂向力和切向力联合作用下及三向载荷作用下的应力分布,对应力最大值进行了分析。其中的超越函数和复杂积分是用数值计算程序处理的。计算结果表明,在三向载荷作用下,最大接触正应力在接触面附近有一个变成拉应力,并且最大数值比只在垂向力作用的情况增大58％。结果还表明,在垂向力和摩擦力联合作用下,最大剪应力出现两个峰值,一个在表面附近,一个在表面以下,且数值增大。在三向载荷作用下,在表面下z=0.25a处最大剪应力峰值超过最大接触应力值,是垂向力作用情况下的3倍。本文还分析了轮轨的接触疲劳破坏。

By way of theoretical analysis, and numerical calculation and photoelastic test, this thesis analyses the interior stress distribution on railway worn profile wheel and rail under the action of three-directional loading, and obtains a series of important results. Provided two contact bodies are in the critical state of relative sliding, the tangential force is proportional to the vertical force. In order to indicate stress distribution and in accordance with the practical contact of wheel and rail, it is supposed that the proportional numerical value between tangential and vertical force is 1/3. Using superposition principle, it calculates the stress distribution under the action of threedirectional loading, and analyses maximum values of the stresses, in which, the transcendental function and complex integral are treated in the process of numerical calculation. The calculation results indicates, under the action of three-directional loading, one of the maximum contact normal stressse turns into tensile stress near the contact area, and the maximum value increases 58% of the situation only uneler the action of vertical force. And the results also show, under the united action of vertical and tangential forces, the maximum shear force turns out two peak values, one is near surface, and another below swrface, and the values greatens. Under the action of three-directional loading, the peak value of maximum shear force at the position of z=0.25a, belowsurfaee, exceeds maximum value of contact normal stress, to be 8 times that under vertical force. There is also analysis of fatigue and on failure on the contact of wheel and rail.