基于耦合锥结构的光纤光栅超声波传感器及其无损检测研究

Fiber Grating Ultrasonic Sensor Based on Coupling Cone Structure and Its Application in Nondestructive Detection

提出一种基于耦合锥结构的光纤光栅超声波传感器,对超声波耦合锥的结构进行数值仿真及优化,分析了光纤光栅长度对超声波探测性能的影响。在此基础上,将所设计的超声波传感器与光谱边带滤波解调技术相结合,用于识别6061型铝合金板中的缺陷。结果表明:所设计的超声波传感器能有效探测铝合金板中传输的兰姆波,通过分析兰姆波时域信号和S0模式幅值的变化量,可以准确判决铝合金板中有无圆孔缺陷及缺陷大小,同时证明所设计超声波传感器具有测量灵敏度高、布置位置灵活可调、可重复利用的优点,在结构体损伤识别等领域具有潜在的应用价值。

A fiber grating ultrasonic sensor based on coupling cone structure is proposed. Numerical simulations and optimization of the ultrasonic coupling cone structure are performed, and the influence of fiber-grating length on the ultrasonic detection performance is analyzed. In conjunction with edge-filter-demodulation technology, the proposed ultrasonic sensor is applied to the identification of defects in a 6061 aluminum alloy plate. The experimental results show that the proposed ultrasonic sensor can effectively detect the Lamb wave transmitted in the aluminum alloy plate. By analyzing the variations in amplitude of the temporal waveform and S0 mode of the Lamb wave, hole-type defects and defect size in the aluminum alloy plate can be readily determined. The proposed ultrasonic sensor has a number of advantages, including high sensitivity, flexible and adjustable positioning, and reusability, all of which are key factors for its potential application in the field of structural damage identification.