弯曲光纤布拉格光栅靶式流量传感器的研究

设计了一种基于光纤布拉格光栅(FBG)的弯曲靶式流量传感器，采用COMSOL软件仿真了弯曲靶臂受力时的应变分布规律，并将两支FBGs分别粘贴于靶臂的外侧和内侧进行应力测试，仿真与实验结果表明在外力作用下靶臂外侧和内侧分别产生拉应变和压应变，FBGs反射中心波长产生红移和蓝移。同时，测试了该结构的温度特性，在20 ℃~40 ℃两支FBGs反射中心波长均与温度呈线性关系，从而可消除温度对测量结果的影响。随后搭建了弯曲靶式FBG流量传感器测量装置，在0~800 L/H范围内的测量结果表明，两支FBGs反射中心波长与水流量呈较好的线性关系，其流量灵敏度为48 L/H。

Study on bending fiber Bragg grating target flow sensor

A bending target type flow sensor based on fiber Bragg grating(FBG) is designed. The strain distribution of bending target is simulated by COMSOL software and measured by two FBGs adhered on outside and inside surface of the target. Simulation and experiment results show that outer and inner sides of the target produce tensile strain and compressive strain respectively, and FBGs reflection wavelength have red shift and blue shift under external force. At the same time, temperature characteristics of the structure are tested and two FBGs reflection wavelength and temperature are linear at 20 ℃~40 ℃. Thereby the method can eliminate the effect of temperature in practical applications. Then measuring device of bending target type flow sensor is built, results show that two FBGs reflection wavelength and water flow have a good linearity within 0 L/H~800 L/H, and corresponding flow sensitivity is 48 L/H.