光纤光栅埋入热喷涂涂层实现新型智能结构控制应用的研究

In the field of aviation, energy, petrochemical and other engineering fields, the structural health monitoring of the important instruments are particularly important. The optical fiber smart structure can realize effectively the damage monitoring and identification of the instrument structures, and the integration between the optical fiber sensor and the instruments is one of the key technologies. Thermal spray technology owns the advantages such as heat-resistant, anti-oxidation and high bonding strength, which is especially suitable for the integration applications. However, the integration of the optical fiber sensor into the thermal spray coating involves the complex inherent interaction mechanism between the fiber and the coating. This project combines the optical fiber smart structure and the thermal spray technology to carry out the multi-disciplinary studies. Firstly, the heat flux evolution during the thermal spray process is analyzed quantitatively. Then, the fiber Bragg grating is selected as the sensing unit, and the thermo-mechanical behavior of the embedded optical fiber is analyzed using the finite element method. Next, according to the ultimate tensile strength of the embedded fiber, the maximal incident heat flux density is fixed and the corresponding experimental elaboration parameters are optimized. Finally, the experimental setup is built up to embed the fiber Bragg grating into the thermal spray coating. The proposed newly smart composite structure can be applied in the field of high-temperature monitoring of the instrument structures.

在航空，能源，石油化工等领域，重要仪器在高温工作环境下的结构健康监测十分关键。通过引入光纤传感器形成“光纤智能结构”能有效实现对仪器结构的损伤监测与识别，其中光纤传感器与仪器的的集成是关键技术之一。热喷涂涂层由于耐高温，抗氧化，粘合强度大等优点尤其适合于此类集成应用。然而如何将光纤传感器埋入涂层并保证其“传感”属性不受影响涉及光纤与涂层材料相互作用的复杂内部物理机制。本项目拟以此为切入口，创新结合光纤智能结构与热喷涂技术展开跨领域基础研究。首先拟首次采用“集总电容”这一电学思想分析热喷涂过程中的热流演变。然后选取光纤光栅为传感单元，基于有限元方法探究光纤及光栅埋入热喷涂涂层的热机械行为，光纤折射率以及光栅性质变化。接下来反馈得出最大入射热流密度阈值并优化热喷涂实验研制参数。最后搭建实验平台探究光纤光栅埋入热喷涂涂层，从而最终实现可应用于高温健康监测领域的新型智能复合结构。

本项目主要针对光纤智能复合结构及其在温度传感领域的应用展开研究，并选择了不同光纤智能复合结构的封装材料（热喷涂涂层材料，有机聚合物胶PDMS等）进行详细研究。具体研究内容包括：（1）基于三维有限元仿真方法，理论研究光纤埋入热喷涂涂层材料这一过程中光纤的热机械行为变化，理论揭示了热源热流温度, 光纤热机械行为与光纤性质变化之间关联性的内部物理机制；（2）提出了一种利用光纤传感器对封装材料PDMS的热光系数进行动态测量的实验方法；（3）基于一种多模光纤传感器与PDMS材料结合实现研制了一种简易的光纤智能结构并应用于温度传感；（4）基于一种错芯干涉式光纤传感器与PDMS材料，光纤光栅共同相结合实现了一种高精度，大动态测试范围的光纤智能结构，灵敏度最高超过10nm/℃。基于以上主要学术成果，发表学术论文14篇（其中，SCI收录国际期刊论文12篇，EI收录国际会议论文2篇）；申请及授权专利4项（其中2项已授权，2项在实质审查过程中）；联合培养了博士1名，硕士2名。