A new device for stress monitoring in continuously welded rails using bi-directional strain method  

作　　者：Ganzhong Liu Hao Liu Anqi Wei Jieling Xiao Ping Wang Shaozheng Li 

机构地区：[1]MOE Key Laboratory of High-speed Railway Engineering,School of Civil Engineering,Southwest Jiaotong University

出　　处：《Journal of Modern Transportation》2018年第3期179-188,共10页现代交通学报（英文版）

基　　金：the fund support by the National Natural Science Foundation of China (No. 51425804, No. U1234201 and No. U1334203)

摘　　要：The technology of continuously welded rails （CWRs） is important in modern railway track structures. To measure rail stress, resistance strain gauges are preferred due to their good stability, sensitivity, and esistance to external interference. Based on the bi-directional strain method, we present a new method for measuring longitudinal rail stress using resistance strain gauges and develop a monitoring device for rail stress to realize long-term and multi-point measurement. Also relevant experimental verification and analysis are conducted. Results indicate that under various constraints the rail stress–strain values can be calculated just with the measured total longitudinal strain and total vertical strain. Considering the measurement error caused by sectional feature of sensors, we put forward a correction equation applicable to different stress conditions. Although the temperature values of the four full-bridge stress gauges can offset each other, the measurement error caused by rail flexural strain can also be eliminated to a certain extent at the same time, the nonuniform distribution of rail cross section temperature and unbalanced flexural strain still affect the measurement error. The experimental results also show that the developed rail-stress-monitoring sensor is suitable for measuring rail stress with reliable working performance.The technology of continuously welded rails （CWRs） is important in modern railway track structures. To measure rail stress, resistance strain gauges are preferred due to their good stability, sensitivity, and esistance to external interference. Based on the bi-directional strain method, we present a new method for measuring longitudinal rail stress using resistance strain gauges and develop a monitoring device for rail stress to realize long-term and multi-point measurement. Also relevant experimental verification and analysis are conducted. Results indicate that under various constraints the rail stress–strain values can be calculated just with the measured total longitudinal strain and total vertical strain. Considering the measurement error caused by sectional feature of sensors, we put forward a correction equation applicable to different stress conditions. Although the temperature values of the four full-bridge stress gauges can offset each other, the measurement error caused by rail flexural strain can also be eliminated to a certain extent at the same time, the nonuniform distribution of rail cross section temperature and unbalanced flexural strain still affect the measurement error. The experimental results also show that the developed rail-stress-monitoring sensor is suitable for measuring rail stress with reliable working performance.

关 键 词：Resistance strain gauge Continuously weldedrail Longitudinal force in rail Bi-directional strainmethod Monitoring instrument 

分 类 号：U216.3[交通运输工程—道路与铁道工程]