光纤光栅振动传感器的振动理论分析

Vibration Theory Analysis on Fiber Bragg Grating Vibration Sensor

为了分析光纤布喇格光栅振动传感器的振动理论,对所建立的物理模型采用了等效刚度变换。首先,根据光纤布喇格光栅振动传感器的振动特点,将其近似为单质点的弦振动模型,然后对其进行等效刚度变换,将其等效为简单的弹簧-质量系统,最后对具有粘性阻尼系统的受迫振动进行了理论分析,通过计算阻尼比,求出该系统的最大振幅和光纤光栅中心波长最大变化量。理论计算和实际测量结果表明:光纤光栅振动中心波长变化量在同一个数量级,能满足基于光纤布喇格光栅振动传感器的周界入侵报警系统的实际应用需要。

In order to analysis the structure of fiber bragg grating（FBG） vibration sensor,a physical model was established and it was equivalent to a simple spring-mass system by doing equivalent transform of stiffness to it.This model was equivalent to a string vibration model of a single particle according to the vibration characteristics of FBG vibration sensor.It was equivalent to a simple spring-mass system by doing equivalent transform of stiffness to it.Finally,the forced vibration theory of the viscous damping system was analyzed.The maximum amplitude of the system and the maximum variation of FBG center wavelength were calculated through the damping ratio of the system.Experimental results indicate that the theoretical maximum variation of the FBG center wavelength and the actual measurement are in the same order of magnitude,which can satisfy the practical application requirements of perimeter intrusion alarm systems based on FBG vibration sensor.