光纤光栅测力环在悬索桥索力监测中的应用

Application of FBG Force-testing Ring in Monitoring Cable Force of Suspension Bridge

桥梁索力监测一直是工程界亟待解决的难题。现有检测手段仅能用于短期测试,无法满足工程长期测试需求。提出了一种基于光纤光栅传感技术的差动式结构的测力装置—光纤光栅测力环,该装置运用了光纤光栅传感新技术和差动式结构设计,解决了索力长期监测的技术瓶颈,即信号的远距离传输和温度补偿。试验研究表明,该测力环信号传输距离超过10 km,温度补偿误差不超过满量程的0.1‰/℃,而且测量精度高,长期稳定性好,可以实现索力的分布式测量。该装置应用于阳逻悬索桥的锚跨索力测量,安装使用方便,实现了索力的远程、长期、实时在线监测,满足了工程测试需求。

The monitoring for cable force of bridges is always considered by engineers as an urgent problem.Present test means are only useful for short-term measurement but cannot meet the demand for long-term monitoring.A novel type of force-testing device which has differential structure design,fiber Bragg grating（FBG） force-testing ring,was put forward based on FBG sensing technology.The device can solve technique bottlenecks of long-term monitoring,which are long distance transmission and temperature compensation of sensing signals.The result of experiment shows that the signal transmission distance of the device exceeds 10 km and the temperature compensation error is below 0.1‰ of full scale per centigrade;（2） it has such nice features as higher measurement precision,better long-term stability and distributing measurement.The new type of force-testing device has been applied on Wuhan Yangluo Yangtze River Bridge.It has more convenient fixing for long distance,long-term and online monitoring of cable force and meets engineering test demand.