【作者】 谢剑锋；

【导师】 张华；

【作者基本信息】 南昌大学 ， 材料加工工程， 2007， 博士

【摘要】 光纤布拉格光栅（FBG）及其在光纤传感器和光纤通信中的应用研究引起了人们普遍的关注，光纤光栅传感器具有不受电磁干扰、信号带宽大、灵敏度高、易于复用、重量轻、结构紧密、适合在高温、腐蚀性或危险性环境使用等优点。这种传感器在大型建筑和油井等特殊场合的安全检测方面具有极为广泛的应用前景。本文主要以光纤布拉格光栅作为研究对象，对光纤光栅的保护、基本特性及传感性能进行了理论、实验和仿真研究，主要内容包括：本文对光纤光栅进行了有效的保护。提出了一种无粗化的光纤表面化学镀的工艺，并且镀层和光纤有较好的结合力。根据本课题后续处理的特点，用镀层的结合力、电学性能、光亮度以及镀速四个性能指标作为判断化学镀工艺是否最佳的主要依据，采用正交试验方法得出了最佳化学镀工艺，最佳工艺为：NiSO₄·6H₂O 25g．L^-1、NaH₂PO₂·H₂O 20 g．L^-1、C₃H₆O₂ 20mL．L^-1、H₃BO₃ 20g．L^-1、NaF1 g．L^-1、糖精2mg．L^-1、PH值4.5、温度86℃。对化学镀后的光纤光栅进行了电镀。并对化学镀和电镀的结果进行了理论分析。根据镀镍FBG的特点，分析了镀镍FBG温度变化时的应力应变，从理论上推导出镀镍FBG的温度灵敏度系数公式并用实验对公式进行了验证，用理论证明了镀镍FBG的波长漂移、应力和应变与温度变化成线性关系。分析了镀镍FBG的温度灵敏度系数与镀层厚度的关系。用ANSYS软件对镀镍FBG在温度变化时的应力应变进行了仿真。理论分析得到镀层厚度为4.26um的镀镍FBG的温度灵敏度系数为14.3235pm／℃，实验值为13.92pm／℃。理论、实验和仿真得到了基本一致的结果。为了研究镀镍光纤布拉格光栅温度灵敏度系数与镀层厚度的关系，用同一根FBG分四次进行化学镀镍，每次化学镀后都测量其镀镍层厚度并进行温度传感实验，从而得到在不同镀镍层厚度时的温度灵敏度系数。讨论了镀镍FBG的温度灵敏度系数公式，理论分析并用实验证明了镀镍层厚度与温度灵敏度系数的关系，理论分析得到镀层厚度分别为2.315um、16.655um、85.255um的镀镍FBG的温度灵敏度系数依次为12.2403pm／℃、17.3782pm／℃、19.6026pm／℃，实验值依次为12.313pm／℃、17.1pm／℃、20.024pm／℃。理论值与实验值基本一致。讨论了镀镍FBG波长移位的滞回现象并用热处理的方法消除了滞回现象。对FBG埋入水泥砂浆后的温度灵敏度系数进行了理论和实验研究。分析了裸光纤光栅和镀镍光纤光栅埋入后的应力应变，推导了FBG埋入后的温度灵敏度系数公式，并用实验验证了温度灵敏度系数公式，对埋入水泥砂浆的FBG受温度变化时的应变进行了理论分析并用ANSYS软件进行了仿真。理论、实验和仿真得到了一致结果。分析了FBG经过保护再埋入金属后温度变化时的应力应变，推导了FBG埋入金属后的温度灵敏度系数公式。以FBG埋入金属铝为例，对埋入金属后的FBG受温度变化时的应力应变进行了理论分析并用ANSYS软件进行了仿真（有限元分析）。理论和仿真得到了一致结果。更多还原

【Abstract】 Recently, fiber Bragg gratings （FBG） have received much attention in the areasof optical Communications and fiber sensors. Fiber Bragg Grating sensors offermany important advantages such as electrically passive operation,big signalbandwidth,high sensitivity and multiplexing capabilities,low weight, smallconfiguration and suitable to be used in the high temperature,corrosive and dangerousenvironment.The fiber bragg grating sensors possess broad application foreground inthe safety scrutiny of especially situation,for example,big architecture and oilwell.Fiber Bragg gratings is the mainly research object in the dissertation. Theprotected technics,basic properties and sensing application of FBG are studied intheory and verified by experiments and simulation.The following are the maincontents:Fiber Bragg grating is protected effectively in the dissertation, a non-coarseningfiber surface electroless plating technics with good adhesion force between layer andfiber is proposed, according to the characters of this project’s post-processing, usingplating layer’s adhesion force,electric properties,brightness and plating depositionrate as the main judgment of the electroless plating, with the help of orthogonaltesting, the technics for optimal elecroless plating is achieved, optimum conditionsare: NiSO₄·6H₂O 25g.L^-1,NaH₂PO₂·H₂O 20g.L^-1,C₃H₆O₂ 20mL.L^-1,H₃BO₃ 20g.L^-1,NaF 1 g.L^-1,saccharin 2mg.L^-1,pH 4.5,temperature 86℃.The Fiber Bragggrating is electroplated after electroless plating.for the more, theoretical analyses forthe results is applied here.According to the characteristic of nickel-coated FBG sensors, the strains andstresses on the nickel-coated FBG sensors under varied temperature were analyzed.The temperature sensitivity of nickel-coated FBG sensors was deduced in theory andverified by experiment. It was proved that wave shift and strains/stresses ofnickel-coated FBG sensors are proportional to the temperature change. Therelationship between plating thickness and temperature sensitivity was analyzed. AFinite Element Analysis Software （ANSYS） was used to simulate the stresses andstrains on the nickel-coated FBG sensors under varied temperatures. When plating thickness was 4.56um, temperature sensitivity was 14.3235pm/℃in theory andexperiment result was 13.92pm/℃.The results of theoretical analysis matches theones from experiments and simulation well.In order to research the relation between temperature sensitivity and platingthickness of nickel coated fiber bragg grating,the same FBG was electroless platedfour times, plating thicknesses of nickel coated FBG and temperature sensitivitieswere measured after every electroless plating, so the temperature sensitivities ofnickel coated FBG with different plating thickness were athieved. The temperaturesensitivity formula of nickel coated FBG was discussed, the relation betweentemperature sensitivity and plating thickness of nickel coated fiber bragg grating wasanalyzed in theory and verified by experiment。When plating thickness were2.315um, 16.655um,85.255um respectively, temperature sensitivities were12.2403pm/℃,17.3782pm/℃,19.6026pm/℃in theory and experiment results were12.313pm/℃, 17.1pm/℃,20.024pm/℃, The results of theoretical analysis matches theones from experiments well. The hysteresis of wave-shift was discussed andhysteresis disappeared after heat treatmentThe temperature sensitivity of naked and nickel-clad FBG which embedded incement mortar was researched by theory and experiment, the strains and stresses onthe embedded FBG sensors under varied temperature were analyzed. Thetemperature sensitivity formula of embedded FBG was deduced in theory and verifiedby experiments. The strains of FBG which embedded in cement mortar under variedtemperature were analyzed in theory and simulated by ANSYS software. The resultsof theoretical analysis matches the ones from experiments and simulation well.The strains and stresses on the FBG in smart metal structure under variedtemperature were analyzed.The temperature sensitivity of FBG in smart metelstructure was deduced in theory. Take FBG （which protected by Ni-P alloy andembedded in Aluminum-Alloy） as example, the strains of FBG under variedtemperature was analyzed in theory and simulated by Finite Element AnalysisSoftware （ANSYS）. The results of theoretical analysis matches the ones fromsimulation well.更多还原