基于能量法的高速铁路无砟轨道钢轨碎弯研究  

Research on the Rail Continuous Bending of Ballastless Track of High-speed Railway Based on Energy Method

作　　者：张向民[1] ZHANG Xiangmin(Central South University,Changsha,Hunan 410075,China)

机构地区：[1]中南大学,长沙410075

出　　处：《铁道工程学报》2019年第3期7-12,共6页Journal of Railway Engineering Society

摘　　要：研究目的:在温度力作用下高速铁路无砟轨道钢轨产生碎弯变形,严重影响行车平稳性、舒适性和安全性。本文将扣件分别假定为连续弹性介质和等间距弹性支座,建立无砟轨道钢轨碎弯分析模型,采用能量法推导相关计算公式,研究扣件刚度与钢轨碎弯波形的关系、碎弯临界温度力、扣件刚度视为连续弹性介质的精度以及为最大限度提高长钢轨稳定性的扣件极限刚度等问题。研究结论:(1)随着钢轨碎弯波长的增加,其临界温度力基本不变,差值不超过1%,但碎弯半波数有了很大的增加,这从理论上解释了碎弯变化的过程,并且有碎弯的长钢轨始终处于不稳定平衡状态;(2)钢轨碎弯存在最不利半波数,并对应最低载荷,主波总波长取10倍扣件间距时,得到主波最不利半波数为5,最低临界温度力为1. 021 5×10~7N;(3)随着扣件刚度的增加,碎弯半波数有所增加,临界温度也升高;随着扣件间距的增加,碎弯半波数也增加,基础模量减小;(4)通过对比分析扣件假定为连续弹性介质和等间距弹性支座计算钢轨碎弯临界温度力,得出当每个半波内有不少于3个扣件时,扣件假定为连续弹性介质能够满足工程精度要求,并且随着半波中扣件数量的增加或者总波长的增加,两者数值更加接近;(5)当半波变形波长为支座间距时钢轨碎弯临界温度力可得最大值,并且随着主波扣件跨数的增加,扣件极限刚度收敛于确定值1. 010 2×10~6N/cm;(6)本研究成果可为高速铁路无砟轨道钢轨碎弯提供理论参考,并可为高速铁路扣件参数的检算及合理性提供计算依据。Research purposes:The rails of ballastless track of high-speed railway will produce continuous bending deformation under temperature force,which seriously affects the running stability,comfort and safety.In this paper,the fasteners are assumed to be continuous elastic medium and equal interval elastic support respectively.The analysis model of the rail continuous bending of the ballastless track is established,and the relevant calculation formula is derived by energy method.Problems such as the relationship between the fastener stiffness and the bending curve of the rail,the critical temperature force of the continuous bending,the precision of the fastener stiffness when regarded as continuous elastic medium,and the ultimate fastener stiffness to furthest improve the stability of the long rail are studied.Research conclusions:(1)As the wavelength of the rail continuous bending increases,the critical temperature force is basically constant,and the difference does not exceed 1%,but the half-wave number of the continuous bending has greatly increased.This result theoretically explains the process of the continuous bending,and the long rails with them are always in an unstable equilibrium state.(2)The most unfavorable half-wave number exists in rail continuous bending,which corresponds to the lowest load.When the total wavelength of the main wave is 10 times the fastener spacing,the most unfavorable half-wave number of the main wave is 5,and the lowest critical temperature force is 1.0215×10^7 N.(3)With the increase of fastener stiffness,the half-wave number of continuous bending and the critical temperature increases.With the increase of the fastener spacing,the half-wave number of continuous bending also increases,and the foundation modulus decreases.(4)By calculating the critical temperature force of the rail continuous bending through the method comparing the fastener assumption of continuous elastic medium and equal interval elastic support,it is concluded that when there are no less than 3 fasteners in each ha

关 键 词：高速铁路 无砟轨道 钢轨碎弯 扣件刚度 能量法 

分 类 号：U213.244[交通运输工程—道路与铁道工程]