地铁扣件Ⅲ型弹条失效有限元分析  

FINITE ELEMENT ANALYSIS OF TYPE Ⅲ RAIL FASTENING CLIP FAILURE IN METRO LINES

作　　者：尚红霞[1,2] 温泽峰[1] 吴磊[3] 李伟[1] 张树峰[1] 金学松[1] 

机构地区：[1]西南交通大学牵引动力国家重点实验室,成都610031 [2]天津铁道职业技术学院,天津300240 [3]西南交通大学峨眉校区机械工程系,峨眉614202

出　　处：《工程力学》2015年第9期210-215,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(51105318);教育部博士点基金项目(20130184110005);四川省科技支撑计划项目(2011GZ0090)

摘　　要：为了分析地铁扣件III型弹条的断裂原因,建立了详细的扣件系统有限元模型,研究了Ⅲ型弹条不同安装状态和弹程对其扣压力和应力的影响。结果表明,弹条中肢插入铁垫板孔长度在69 mm^76 mm时,对弹条的扣压力影响很小,但对弹条最大等效应力影响比较大;同时,随着弹条中肢插入铁垫板插孔长度的增加,弹条后端与铁垫板的接触状态由线接触转化为多点接触,使得弹条后端圆弧与铁垫板端部发生挤压,产生局部应力集中。随着列车的反复通过,弹条在应力集中处容易萌生裂纹,最终裂纹扩展导致弹条发生疲劳断裂。数值分析结果与现场多数弹条断裂破坏位置相吻合。在线路运营维护中,应将弹条后端圆弧与铁垫板端部的距离严格控制在8 mm^10 mm内。In order to analyze the reasons for type III rail fastening clip fracture in metro lines, a detailed finite element model of the rail fastening system was established to study the effect of the clip＇s different installation states and the vertical displacement of its finger on its clamping force and stresses. Results show that the when the length of the center leg of the clip inserting into the shoulder is between 69 mm and 76 mm, it has little effect on the clamping force, but a large effect on the maximum equivalent stress in the clip. As the distance increases, the contact state between the clip and the shoulder becomes multi-point contact instead of line contact, and localized extrusion pressure occurs between the rear arch of the clip and the shoulder end, which results in a stress concentration in the clip. After repeated passage of trains, crack initiation can easily occur in the clip＇s stress concentration area, and its crack propagation may finally accelerate its fatigue fracture. The numerical results agree well with the fracture position of a majority of clips in metro lines. In track operation and maintenance, the distance between the inner arc of the rear arch and the shoulder end should be between 8 mm to 10 mm.

关 键 词：Ⅲ型弹条 失效 安装状态 应力 有限元法 

分 类 号：U213.531[交通运输工程—道路与铁道工程]