摘要
为研究并模拟列车频繁制动作用导致的钢轨累积位移现象,以弹条Ⅲ型分开式扣件作为试验对象,对钢轨进行长期重复拉力加载,并通过数据采集软件采集拉力及钢轨位移数据,得到扣件纵向阻力与钢轨残余变形规律,获得在未超过扣件最大阻力的单向循环荷载加载下,钢轨纵向累积位移与加载循环次数的关系。研究结果表明:钢轨纵向累积位移随循环次数的增加而增大,在经过大量重复加载后残余位移增长速率有所减小,但位移值有进一步增大的趋势。对于弹条Ⅲ型分开式扣件,钢轨纵向残余位移f(x)和循环次数x间的函数关系近似满足幂函数形式:f(x)=0.01758x^(0.2332),且拟合度较高(R^(2)=0.9351)。该拟合公式具有一定的可信度,可以用于预测获得不同重复荷载作用后钢轨纵向累积位移值。经过大量纵向荷载重复作用后,扣件纵向刚度、扣件最大纵向阻力和扣件滑移阻力会有所增大,扣件弹塑性界限位移将会有所减小。研究成果可用于预测多次加卸载之后钢轨累积残余位移值,为相关线路设计与养护维修提供借鉴,同时也可为扣件本构关系的改进提供试验依据。同时可将钢轨残余位移预测值和扣件纵向刚度结合后计算出加载时钢轨最大纵向位移,通过对比不同地段钢轨最大纵向位移的限值,可以判断多次重复荷载后加载瞬间钢轨纵向位移是否超限。
In order to study and simulate the cumulative displacement phenomenon of fastener caused by frequent train braking,taking spring-bar type Ⅲ split fastener as the test object,long-term repeated tension loading on the rail was carried out.The tension and rail displacement data were collected through the data acquisition software.And then the longitudinal resistance of the fastener,rail residual deformation law,and the relationship between the longitudinal cumulative displacement of the rail and the number of loading cycles under the unidirectional cyclic load of no more than the maximum resistance of the fastener were obtained.The results are as follows.The longitudinal cumulative displacement of the rail increases with the increase in the number of cycles.After many repeated loads,the growth rate of the residual displacement has decreased,but the residual displacement value has a further increasing trend.For spring-bar Ⅲ type split fastener,the functional relationshipbetween the longitudinal cumulative displacement of the fastener f(x)and the number of cycles x approximately satisfies the power function form:f(x)=0.01758x^(0.2332),and has a high degree of fit(R^(2)=0.9351),with a high degree of credibility can be used to predict and obtain the longitudinal cumulative displacement value of the rail after different repeated loads.After the repeated action of many longitudinal loads,the longitudinal stiffness of the fastener,the maximum longitudinal resistance of the fastener and the sliding resistance of the fastener will increase,and the elastic-plastic limit displacement of the fastener will decrease.In conclusion,the research results can be used to predict the cumulative residual displacement of rail after multiple loading and unloading,provide reference for relevant line design,maintenance and repair,and also provide experimental basis for improving the constitutive relationship of fasteners.At the same time,the maximum longitudinal displacement of the rail during loading can be calculated by combining the p
作者
曾志平
胡籍
王卫东
黄相东
李平
田春雨
ZENG Zhiping;HU Ji;WANG Weidong;HUANG Xiangdong;LI Ping;TIAN Chunyu(School of Civil Engineering,Central South University,Changsha 410075,China;MOE Key Laboratory of Engineering Structures of Heavy Haul Railway(Central South University),Changsha 410075,China;Guangzhou Metro Design&Research Institute Co.,Ltd.,Guangzhou 510010,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2022年第5期1243-1249,共7页
Journal of Railway Science and Engineering
基金
湖南省自然科学基金资助项目(2019JJ40384)
广州地铁设计研究院股份有限公司科学技术开发项目(2019K028)
中南大学中央高校基本科研业务费专项资金资助项目(2019zzts873)。
关键词
循环荷载
列车频繁制动
弹条Ⅲ型分开式扣件
钢轨纵向累积位移
本构关系
残余变形
cyclic load
frequent train braking
spring-bar Ⅲ type split fastener
longitudinal cumulative displacement of rail
constitutive relationship
residual deformation
