过度磨耗钢轨的打磨廓形设计方法

Design method of grinding profile of over worn rail

针对过度磨耗钢轨的打磨,提出一种以圆弧切点为关键参数的钢轨廓形设计方法;以轮轨接触位置为优化区域,以钢轨磨耗和打磨材料去除量作为优化目标函数,以廓形边界范围、凹凸性、脱轨系数和轮轨横向力为约束条件,建立磨耗钢轨打磨设计廓形多目标函数;集成多元模拟退火寻优算法进行求解;为了得到能代表重载线路曲线区段的钢轨廓形,作为优化的输入数据,采用最小二乘距离算法、算术平均算法、加权平均算法和散点重构算法得出4种钢轨代表廓形;使用Pearson相关系数、Kendall秩相关系数和Spearman秩相关系数计算出4种算法的钢轨代表廓形与实测廓形接触点概率分布曲线的相关性,取相关性最高的代表廓形为等效重载线路曲线区段的实际廓形;对某重载线路过度磨耗钢轨的经济性打磨廓形以及采用圆弧型廓形设计方法的优化廓形进行分析。分析结果表明:优化廓形与现场打磨廓形相较,截面廓形磨削量减少69.56mm^(2),下降64.98%,脱轨系数小幅增大,轮轨横向力基本不变,轮对横移变化较小,曲线通过性能相近,80万次通过量下的磨耗面积增加2.19mm^(2),钢轨的磨耗速率略微增大,整体仍延长了钢轨寿命。

A rail profile design method with the arc tangency point as the key parameter was proposed for the grinding of over worn rail.Specifically,taking the wheel-rail contact region as the optimization area and the rail wear and the removed amount of grinding material as the optimization objective function,taking the profile boundary,concavity and convexity,derailment coefficient and wheel-rail lateral force as the constraint conditions,the multi-objective function of designed grinding profile of worn rail was established.The multiple simulated annealing optimization algorithm was integrated for solutions.To obtain the rail profile representing the curve of a heavy haul line,which was adopted as the optimized input data,the representative profiles of four kinds of rails were obtained by using the least square distance algorithm,arithmetic average algorithm,weighted average algorithm and scatter reconstruction algorithm.The correlations between the rail representative profiles of the four algorithms and the measured profile contact point probability distribution curve were calculated by using the Pearson correlation coefficient,Kendall rank correlation coefficient and Spearman rank correlation coefficient,and the representative profile with the highest correlation was taken as the actual profile of the curve section of the equivalent heavy haul line.The economical grinding profile of over worn rail in a heavy haul line and the optimized profile using the arc profile design method were analyzed.Analysis results show that compared with the on-site grinding profile of rail,the optimized rail profile has a reduced grinding and cutting amount for its sectional profile by 69.56mm^(2),a decrease of 64.98%,a slightly increased derailment coefficient,the same lateral wheel-rail force,small lateral wheelset displacement change,and similar curve passing performance.Although the wear area under 800000passes increases by 2.19mm^(2),and the wear rate of rail slightly rises,the overall service life of rail is still prolonged.3tabs,17figs,30refs.