5MN光纤布拉格光栅力值传感器

针对山体滑坡中大力值监测的应用需求,提出了基于光纤Bragg光栅(FBG)的5 MN力值传感器。该传感器采用8根FBG构成4组光栅偶对圆柱弹性体的应变进行采集,光栅偶能有效地补偿温度对FBG尺寸的影响。通过ANSYS数值模拟计算并优化了圆柱弹性体的结构尺寸,并按照国家规程进行了传感器检定实验。实验结果表明,该传感器的直径为124mm,长度为302mm,应力测量范围为500~5 000kN,综合精度为1%,最大力值对应的波长变化为2 567pm,灵敏度为2kN/pm。该传感器除具有光栅传感的基本特点以外还具有结构简单、量程大、精度高等优点,不仅适用于滑坡力值监测,还适用于建筑、化工、煤矿、军事等领域的力值监测。

Five MN force sensor based on fiber Bragg grating

In view of the increasing demand for strong force value monitoring in landslide, a 5 MN force sensor based on Fiber Bragg Grating(FBG) was proposed.The sensor adopted 8 FBGs to compose 4 group of grating pair for cylindrical elastic strain collection.The grating pair can effectively compensate the effect of temperature on the size of FBG.The dimension of the cylindrical elastomer was determined and optimized via ANSYS numerical simulation.Then the force sensor was tested according to the national regulations.The experimental results show that the sensor with diameter of 124 mm and length of 302 mm, can provide a measurement range of 500-5000 kN and an overall accuracy of 1%.In addition, the wavelength variation corresponding to the maximum force value is 2 567 pm and the sensitivity is 2 kN/pm.The sensor is characterized by simple structure, large measuring range and high precision besides basic characteristics of the grating sensing.The sensor can be applied to force monitoring not only in landslide, but also in construction, chemical industry, coal mine, military and other fields.