光学 精密工程, 2014, 22 (2): 311, 网络出版: 2014-03-03
用于船舶结构监测的大量程光纤布拉格光栅应变传感器
Large range FBG sensor for ship structure health monitoring
光纤传感器 光纤布拉格光栅 应变传感器 健康监测 船舶结构 复合结构 有限元法 fiber sensor Fiber Bragg Grating(FBG) strain sensor health monitoring ship structure composite structure finite element method
摘要
平板结构的贴片式光纤光栅传感器应变测量范围较小, 难以满足船舶结构健康监测中的应变测量要求。本文采用不锈钢材质, 设计了一种采用环形平面弹簧和平板复合结构的贴片式传感器, 通过环形平面弹簧结构将复合结构的大应变转化为光栅的小应变, 降低被测物体与光栅之间的应变耦合系数, 实现了大应变测量。理论分析了复合结构的传感原理, 通过有限元方法仿真了该结构的应力分布, 结果证明了该结构能够实现大应变测量。将传感器胶粘在特种钢试件上进行了载荷试验, 试验结果表明: 该复合结构传感器的量程大于20 000 με, 且线性度较好, 相关系数大于0.99。另外, 设计的传感器体积较小, 便于安装, 能较好地解决船舶结构健康监测中的大应变测量问题。
Abstract
Fiber Bragg Grating(FBG) sensor with a stickup plane structure can not test the strain precisely in ship structure health monitoring due to its small measuring range. For overcoming this problem, this paper designs a composite structure stickup FBG sensor composed of an annular plane spring and a slab on the basis of stainless steel. This kind of stickup FBG sensor can convert the large strain of composite structure into a small strain of FBG by the annular plane spring. By decreasing the strain coupling coefficient between FBG and tested structure, large-scale strain test is implemented. The sensing principle of the composite structure is analyzed and the stress and strain distribution of the stickup FBG sensor are simulated through finite element method. The simulation result demonstrates the feasibility of this structure in a large strain test. Finally, a loading experiment are performed on a special steel sample. The experiment result shows that this structure has a measuring range more than 20 000 με and good linearity. In addition, the correlation coefficient is up to 0.99. As a conclusion, the sensor is convenient for setting up because of the small volume, and can resolve the problem of large strain test in ship structure health monitoring with good performance.
吴晶, 吴晗平, 黄俊斌, 顾宏灿. 用于船舶结构监测的大量程光纤布拉格光栅应变传感器[J]. 光学 精密工程, 2014, 22(2): 311. WU Jing, WU Han-pin, HUANG Jun-bin, GU Hong-can. Large range FBG sensor for ship structure health monitoring[J]. Optics and Precision Engineering, 2014, 22(2): 311.