金属化保护的光纤布拉格光栅温度传感模型  

Temperature Sensitization Model of Fiber Bragg Grating with Metal Coating

作　　者：冯艳[1] 张华[1] 李玉龙[1] 彭刚[1] 

机构地区：[1]南昌大学机电工程学院机器人与焊接自动化重点实验室,江西南昌330031

出　　处：《光学学报》2009年第2期336-341,共6页Acta Optica Sinica

基　　金：国家973计划前期基础研究专项(2005CCA04300);国家自然科学基金(60844005);江西省自然科学基金(2008GQC0013)资助项目

摘　　要：光纤布拉格光栅(FBG)传感器是智能金属结构首选的信息传输与传感的载体,埋入金属材料内部的FBG传感器必须要经过适当保护,金属镀层是最有效的保护方法之一。FBG经过镀前预处理,通过化学镀方法可获得均匀的金属保护镀层。针对金属保护镀层,应用弹性力学基本原理分析了由于镀层与FBG传感器的热膨胀系数不同而产生的热应力,建立了镀层厚度对FBG温度传感性能影响的数学模型。镀镍FBG的升温和降温传感实验表明,升温时的实际温度灵敏度系数与模型值之间误差为6.22%,降温时的实际温度灵敏度系数与模型值之间误差为6.75%。与裸FBG相比,化学镀镍后的FBG温度灵敏度系数提高1倍多。结果表明该温度模型从理论上解释了镀层金属热应力对FBG起到的温度增敏作用。The optical fiber Bragg grating （FBG） sensor has great potential to be used for measuring temperature, strain, or even detecting fracture in metal materials. Embedding FBG sensor into metal materials is difficult and changing. Metal coating is one of the most efficient methods to protect FBG. Uniform metal coating can be applied in FBG sensor using electroless plating. The temperature changes induce thermal stress between the metal coating and the FBG due to their different thermal expansion coefficients. For the nickel - clad FBG, the thermal stress was analyzed and the math model about the coating thickness influencing temperature sensitivity was built. Temperature increase and decrease sensing experiment of the nickel-clad FBG shows, for increasing temperature and decreasing temperature, the errors between the practical temperature sensitivity coefficient and the model coefficient are 6. 22 % and 6.75 % respectively. Compared with the naked FBG, the temperature sensitivity of the nickel-clad FBG is increased to two times and more. The results show the model is feasible to explain the temperature sensitivity enhancing mechanism.

关 键 词：光纤光学 光纤布拉格光栅 金属保护镀层 热应力 温度增敏 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]