Bettini Paolo, Guerreschi Erika, Sala Giuseppe
Department of Aerospace Science and Technology, Politecnico di Milano, 20156 Milan, Italy.
Sensors (Basel). 2015 Jan 12;15(1):1321-41. doi: 10.3390/s150101321.
The interest of the aerospace industries in structural health and usage monitoring systems is continuously increasing. Among the techniques available in literature those based on Fibre Bragg Grating sensors are much promising thanks to their peculiarities. Different Chirped Bragg Grating sensor configurations have been investigated in this paper. Starting from a numerical model capable of simulating the spectral response of a grating subjected to a generic strain profile (direct problem), a new code has been developed, allowing strain reconstruction from the experimental validation of the program, carried out through different loading cases applied on a chirped grating. The wavelength of the reflection spectrum for a chirped FBG has a one-to-one correspondence to the position along the gauge section, thus allowing strain reconstruction over the entire sensor length. Tests conducted on chirped FBGs also evidenced their potential for SHM applications, if coupled with appropriate numerical strain reconstructions tools. Finally, a new class of sensors-Draw Tower Grating arrays-has been studied. These sensors are applicable to distributed sensing and load reconstruction over large structures, thanks to their greater length. Three configurations have been evaluated, having different spatial and spectral characteristics, in order to explore possible applications of such sensors to SHM systems.
航空航天工业对结构健康与使用监测系统的兴趣在不断增加。在文献中现有的技术中，基于光纤布拉格光栅传感器的技术因其特性而颇具前景。本文研究了不同的啁啾布拉格光栅传感器配置。从一个能够模拟受一般应变分布的光栅光谱响应的数值模型（正问题）出发，开发了一种新代码，通过对啁啾光栅施加不同加载情况进行程序的实验验证来实现应变重构。啁啾光纤布拉格光栅反射光谱的波长与沿测量段的位置一一对应，从而能够在整个传感器长度上进行应变重构。对啁啾光纤布拉格光栅进行的测试还证明，如果与适当的数值应变重构工具相结合，它们在结构健康监测应用中的潜力。最后，研究了一类新型传感器——拉丝塔光栅阵列。由于其更长的长度，这些传感器适用于大型结构的分布式传感和载荷重构。评估了三种具有不同空间和光谱特性的配置，以探索此类传感器在结构健康监测系统中的可能应用。
