线路参数对地铁小半径曲线低轨滚动接触疲劳的影响分析

Analysis of the Influence of Line Parameters on Rolling Contact Fatigue in Low Rail on Small Radius Curve of Metro Line

针对国内某地铁线路在小半径曲线低轨上产生的疲劳损伤问题,通过建立地铁车辆系统动力学模型和损伤函数模型,分析了曲线超高、摩擦系数和轨底坡这3个线路参数对低轨滚动接触疲劳的影响,并提出了相应的减缓措施。研究结果表明,增大曲线超高与低轨摩擦系数均会降低低轨的疲劳损伤值,但低轨会发生疲劳损伤的区域基本保持不变;随着低轨轨底坡的不断减小,低轨会发生疲劳损伤的区域将从轨顶偏向外侧处逐渐移至靠近轨距角处,同时疲劳损伤峰值会先减小随后而又增大;适当增大曲线超高与低轨摩擦系数,并将低轨轨底坡调为1/70,可减缓该小半径曲线低轨滚动接触疲劳的形成和发展。

Aiming at the rolling contact fatigue(RCF)in low rail on small radius curve of a domestic metro line,the metro vehicle system dynamics model and the damage function model are established to analyze the influence of three line parameters of curve superelevation,friction coefficient and rail cant on the RCF in low rail,and the corresponding mitigation measures are put forward.The research results show that increasing the curve superelevation and the friction coefficient of low rail will reduce the RCF damage value of low rail,but the area where the RCF occurs in low rail remains basically unchanged.With the continuous reduction of the low rail cant,the area where the RCF occurs in low rail will gradually move from the outside of the rail top to near the gauge angle,and the peak value of RCF damage will first decrease and then increase.Increasing the curve superelevation and the friction coefficient of low rail to an appropriate extent and adjusting the low rail cant to 1/70 can slower down the formation and development of the RCF in low rail on small radius curve.