温补型光纤Bragg光栅压力传感器在锚杆支护质量监测中的应用

为了改善现有光纤光栅压力传感器应变-温度交叉敏感的问题,基于光纤光栅传感原理及弹性膜片结构,设计了一种新型的温度补偿压力传感器。建立了膜片结构变形力学模型,推导出了光纤光栅中心波长漂移与压力之间的数学关系,建立了传感器灵敏度与膜片材料和结构尺寸参数之间的数学方程,Matlab数值分析了膜片参数对灵敏度的影响,利用有限元软件ABAQUS对膜片变形特征进行了仿真分析。传感器理论压力灵敏度为40.43 pm/MPa,标定实验的灵敏度为35.6 pm/MPa,经温度补偿后的实际灵敏度为37.62 pm/MPa,实现了压力测量中的温度补偿。测试结果表明该传感器具有良好的线性度、较低的啁啾性及较高的稳定性,现场应用结果证实了光纤光栅传感技术在煤矿安全监测中的可行性,适合进一步推广应用。

Application of temperature compensation fiber Bragg grating pressure sensor for bolting quality monitoring

For the purpose of improving the existing Fiber Bragg grating pressure sensors’ cross-sensitivity of strain and temperature,a novel type of FBG pressure sensors with temperature compensation was developed based on the fundamental principles of FBG and elastic diaphragm structure.The mechanical deformation model of diaphragm structure was established and the mathematical relationship between the FBG center wave length drift and pressure as well.Also,the influence of diaphragm’s material and dimensions on the sensitivity was numerically analyzed using Matlab,and additionally the numerical simulation of the deformation characteristics of the diaphragm was conducted with finite element software ABAQUS.The theoretical value of the sensors’ pressure sensitive value is 40.43 pm/MPa,35.6 pm/MPa by calibration test and 37.62 pm/MPa with temperature compensation.The performance test indicated that this sensor had a good linearity,low frequency chirp and high stability.The application results show the feasibility of fiber Bragg grating sensing technology in coal mine monitoring and suitable for the further popularization and application.