大秦铁路钢轨轨角型核伤的扩展与安全评估  

Growth and Safety Appraisement of Oval Flaws at Rail Corners in Da-Qin Railway

作　　者：习年生[1] 李晓宇 王卫东 

机构地区：[1]中国铁道科学研究院铁道科学技术研究发展中心,北京100081

出　　处：《失效分析与预防》2011年第1期15-18,27,共5页Failure Analysis and Prevention

基　　金：中国铁道科学研究院铁道科学技术研究发展中心项目(2004YF042006YF14)

摘　　要：对大秦铁路线路上某种钢轨在使用过程中出现的核伤进行研究,通过对大量核伤断口的观察分析确定了钢轨轨角型核伤的发展模式(包括起源位置和扩展方向);采用检测方法测量在不同时间(累计通过总重)下的核伤尺寸,得到一系列关于累计通过总重和核伤尺寸的数据组,对测量数据进行统计分析得到不同核伤尺寸下的裂纹扩展速率;依据轨角型核伤发展模式建立了简化的断裂力学模型和临界尺寸评估方法,并进行安全评估,得出大秦重车线该种钢轨核伤的临界裂纹尺寸和临界应力。Oval flaw is one of the chief failure modes of rails. Oval flaws occurring at a certain rail in DaQin railway have been studied. Fracture surface observation and analysis were made to confirm the development mode of oval flaws at rail comers, including crack origin and propagation direction. The sizes of oval flaws in different periods or under different accumulative pass gross weights have been measured by rail flaw detection and a series of group data were obtained about accumulative pass gross weight and oval flaw size. Then the group data were analyzed statistically to get the growth rates under different flaw sizes. A simplified fracture mechanics model of oval flaws at rail corners has been set up according to the development mode, based on which safety appraisement has been done and correlative critical crack sizes of oval flaws and critical stress for the rail in DaQin heavyhaul railway have been given.

关 键 词：钢轨 核伤 裂纹扩展 安全评估 

分 类 号：U213.4[交通运输工程—道路与铁道工程]