浮空器柔性复合蒙皮变形光纤光栅传感方法

Optical Fiber Grating Sensing Method for Flexible Composite Skin Deformation of Aerostat

针对浮空器气囊蒙皮变形的实时监测需求,提出了基于光纤光栅(fiber Bragg grating,简称FBG)的柔性复合蒙皮变形传感方法。根据蒙皮材料的多层结构特点及光纤光栅传感原理,设计了“光纤光栅-粘贴层-基体”的柔性蒙皮传感结构。通过对传感结构进行理论分析,得知平均应变传递效率随粘贴层剪切模量增加而增大。实验采用GD414和DP420两种不同剪切模量的粘接剂将光纤传感器粘接在柔性蒙皮表面,建立了传感解调实验系统。分析了浮空器柔性复合蒙皮变形光纤光栅传感器灵敏度及重复性,研究了两种不同胶接剂封装下光纤光栅中心波长随曲率变化的关系,结果显示剪切模量较大的DP420胶接剂封装的FBG具有良好的线性度和重复性,其灵敏度可达145.4 pm/m-1。对浮空器柔性复合蒙皮变形进行重构分析,验证了传感方法的可行性。研究结果表明,光纤光栅传感器可用于柔性复合蒙皮变形监测,在浮空器气囊蒙皮形态监测中具有广阔的应用前景。

In response to the real-time monitoring requirements of the aerostat skin deformation,a flexible com⁃posite skin deformation sensing method based on fiber Bragg grating(FBG)is proposed.According to the char⁃acteristics of the multilayer structure of the skin material and the principle of FBG sensing,a flexible skin sens⁃ing structure of"FBG-adhesive layer-base"is designed.Through theoretical analysis of the sensing structure,it is concluded that the average strain transfer efficiency increases with the increasing of the shear modulus of the adhesive layer.In the experiment,two adhesives with different shear modulus,GD414 and DP420,are used to bond the FBG sensor to the surface of the flexible skin and a sensor demodulation experiment system is estab⁃lished.The sensitivity and repeatability of the aerostat flexible composite skin deformed FBG sensor are ana⁃lyzed.The relationship between the center wavelength of the FBG and the curvature of the FBG encapsulated by two different adhesives is studied.The FBG encapsulated by DP420 adhesive which with larger shear modu⁃lus has good linearity and repeatability and its sensitivity can reach 145.4 pm/m-1.Reconstruction analysis of the deformation of the flexible composite skin of the aerostat has verified the feasibility of the sensing method.The research results show that the FBG sensor can be used to monitor the deformation of flexible composite skin and it has broad application prospects in the shape monitoring of aerostat skin.