超声激励-相移光纤光栅分布全方位传感的机械损伤识别与成像技术

项目名称： 超声激励-相移光纤光栅分布全方位传感的机械损伤识别与成像技术

项目编号： No.51505187

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 机械、仪表工业

项目作者： 孟丽君

作者单位： 江汉大学

项目金额： 20万元

中文摘要： 相移光纤光栅是在均匀光栅栅区引入一定相移而形成的特殊光栅，除具有光纤光栅的抗电磁干扰、分布式多参数测量、可靠性高等特点外，还具有极高波长选择度和极窄线宽的特殊光谱特性。本项目将相移光纤光栅传感技术与超声波检测技术相结合，通过超声波激励机械装置，利用分布式布置的相移光纤光栅测量超声应变波、结构应力等机械损伤的场信号，创建大型机械装备结构损伤识别与成像的新理论和新技术。项目主要研究全方位超声敏感的相移光纤光栅传感体结构及传感特性、相移光纤光栅分布式测量的结构损伤场信号高速解调与信息融合、基于分布式测试数据的机械损伤的识别与成像算法等科学问题。本项目的创新点在于突破传统机械损伤的检测局限，将相移光纤光栅分布传感技术和超声波检测技术相结合，研究机械结构损伤在线动态检测、识别与成像的基础问题。本项目的开展对提高大型机械装备安全稳定运行水平，丰富和发展机械设备状态检测与故障诊断理论，具有重要的意义。

中文关键词： 相移光纤光栅；超声检测；损伤识别；损伤成像

英文摘要： Phase shifted fiber Bragg grating is a special fiber grating which is introduced a certain phase shift in the gate region of a uniform fiber Bragg grating. In addition to having the detection advantages of fiber Bragg gratings such as electromagnetic interference immunity, distributed multi-parameter measurement, high reliability characteristics, it also has the special spectral characteristics of high wavelength selection and very narrow line width. In this project, the phase shifted fiber Bragg grating sensing technology is combined with ultrasonic detection technology to create a new damage identification and imaging theory of the large mechanical equipments by using ultrasonic wave to excite the mechanical structure and the distributed phase shifted fiber Bragg gratings to measure the mechanical damage field signals such as ultrasonic waves, structure stress. It focuses on the following scientific problems: the structure and sensing characteristics of the phase shifted fiber Bragg grating sensor which is sensitive to ultrasonic wave in all directions; the high-speed demodulation and information fusion technology of distributed phase shifted fiber Bragg grating signals; mechanical damage identification and imaging algorithm based on distributed test data. The innovation of this project is that it breaks through the traditional mechanical damage detection technology limitation and connects the phase shift fiber grating sensing technology with ultrasonic detection technology to study the basic problems of mechanical structure damage online dynamic detection, identification and imaging. The launching of this project can improve the safe and stable operation level of the large mechanical equipments as well as enrich and develop the theory of the state detection and fault diagnosis of mechanical equipments.

英文关键词： phase shifted fiber Bragg grating;ultrasonic detection;damage identification;damage imaging