光纤应变传感器在桥梁应变监测上的应用研究

随着外界应力的变化,光纤应变传感器中干涉光发生相应移动,输出多个干涉明暗变化,光波相位发生改变。利用此特性,通过对干涉光相位的解调,就可以测出应变的大小。实验结果与理论分析证明,该测试系统具有结构简单、测量范围大、稳定性好、灵敏度和信噪比高等特点,其测试精度达1微应变。可满足土木工程结构健康监测的要求,特别为桥梁的应变监测提供了新方法。

Application of Fiber Optic Strain Sensor in Monitoring of Bridge Strain

With the changing of outside stress,the interference light in fiber optic strain sensor will shift correspondingly,the multiple interference light and shade changes output,and the light phase changes.According to this characteristic,the demodulating of the interference light phase can achieve the value of the strain.Both experiment results and theoretical analysis indicate that the test system has the characteristics of simple structure,large scope of measurement,good stability,high sensitivity and SNR(signal to noise ratio),and its test precision can reach 0.1με.All this can satisfy the requirement of health monitoring the civil engineering structure,so a new method for monitoring the strain of bridge is provided.