基于正弦式波纹膜片的压差式FBG静力水准仪

Differential pressure type FBG static level based on sinusoidal corrugated diaphragm

为解决建筑物不均匀沉降长期、可靠监测的问题,基于连通器原理,推导了膜片半径r、刚度K、光纤自由段长度l、波长变化量Δλ_(B)等参数和沉降量的线性关系式。以此设计了带有正弦式波纹膜片的压差式光纤布拉格光栅(FBG)静力水准仪,并通过标定试验验证压差式FBG静力水准仪的传感性能。结果表明:此静力水准仪灵敏度不小于13.2 pm/mm,综合误差不大于3.26%,相关性系数均在0.99以上。该型静力水准仪传感性能满足工程结构沉降测量的要求,丰富了FBG静力水准仪的研究,具有理论和现实意义。

In order to solve the problem of long-term and reliable monitoring of uneven settlement of buildings,based on the theory of communicating vessels,linear relationship between the parameters such as diaphragm radius r,stiffness K and free section length of optical fiber l,wavelength variation Δλ_(B) and settlement is derived.Based on this,a differential pressure type fiber Bragg grating(FBG)static level with sinusoidal corrugated diaphragm is designed.The sensing performance of differential pressure type FBG hydrostatic leveling is verified through calibration test.The results show that the sensitivity of the hydrostatic level is not less than 13.2 pm/mm,comprehensive error is not more than 3.26 %,and correlation coefficient is more than 0.99.The sensing performance of this type of static level meets the requirements of engineering structure settlement measurement,enriches the research of FBG hydrostatic level,and has theoretical and practical significance.