长标距光纤布拉格光栅应变监测研究

Study of Strain Monitoring Based on Long-gage Fiber Bragg Grating

一些大型工程结构体积大、跨度长,传统的小标距光纤布拉格光栅应变传感器很难监测整体应变。长标距光纤布拉格光栅(FBG)应变传感器作为光纤光栅传感器的一种以其高精度和更大测量范围受到了关注。本文首先介绍FBG传感原理,然后对长标距和短标距FBG应变传感器进行应变监测研究,同时利用引伸计对应变进行监测。结果表明同短标距FBG应变传感器相比长标距FBG应变传感器测得的应变和引伸计测得的应变更接近,反射波长和应变具有更好的相关性,相关系数为0.9997优于短标距传感器相关系数0.9992。长标距FBG传感器更适合对结构整体应变监测。

It is difficult for short-gage fiber Bragg grating to monitor the overall strain of Some major engineering structures with large volume and long span. This thesis firstly introduces the sensing theory, and then monitors strain using long-gage and short-gage FBG strain sensor respectively. Meanwhile, uses extensometer monitor strain. The results show that the strain measured by the long-gage FBG strain sensor, compared with short-gage FBG strain sensor, is closer to that measured by extensometer . The long-gage FBG’s correlation coefficient is 0.9997 and the short-gage FBG’s is 0.9992, the long-gage FBG strain sensor obtain better correlation coefficient of reflection wavelength and strain. Long-gage FBG sensor is more suitable to monitor strain of structural integrity.