基于疲劳传感器的桥梁载荷谱检测研究

设计了一种结构独特的应变增幅器,使疲劳计的响应灵敏度大大提高,从而使疲劳计较高响应门槛值能与结构高周疲劳情况相匹配,扩展了疲劳计的应用范围,满足了桥梁工程结构疲劳检测要求.由恒幅标定数据和等效原理用插值方法得到复杂加载下疲劳响应计算方法,并根据桥梁载荷谱的瑞利分布特点,得到该分布下的疲劳响应计算方法.采用增幅器的双疲劳计结构设计,利用疲劳计响应的非线性特性,得到疲劳传感器电阻变化与桥梁瑞利载荷谱的对应关系.该传感器的检测原理提供了一种新的工程疲劳检测方法,它较目前采用的其它方法效率高、精度好,适用于长期疲劳监测.疲劳实验表明,实验载荷谱与预测载荷谱相当吻合,所设计的疲劳传感器性能良好、满足桥梁疲劳载荷检测要求.

Monitoring Research of Long Span Bridge Based on Fatigue Life Gage

A new strain multiplier was designed,the strain multiplier greatly promotes the fatigue life sensor's sensitivity.The relatively small surface strain of engineering structure can be amplified above fatigue life sensor's threshold.Therefore,its appliance can be in low strain cases which is in very common situation.And it satisfy the demands of fatigue monitoring for bridge.Firstly,on the basis of fatigue life gauge response data that calibrated in the condition of constant amplitude loading,the complex fatigue loading response can be reached with the aid of data insertion and equivalent resistance change method.Secondly,by using this analytical mode,the Rayleigh density distribution which is the loading characteristic of bridge structure response was also conducted successfully.The relation between resistance change of fatigue life gauge and Rayleigh distribution parameter was established by a program calculation with dual sensor design in a fatigue life gauge and its great non-linearity character.It has high efficiency and more accuracy compared to the other methods recently in use,and is vary suitable for long time monitoring of long-span bridge.Experiment results explain that this fatigue life gauge has well properly and satisfactory for monitoring fatigue of bridge.