光纤Michelson干涉仪的声发射检测实验研究

Experimental research on acoustic emission detection using an optical fiber Michelson interferometer

提出了一种基于Michelson干涉仪原理构成的非接触式光纤超声传感系统,用于固体中传播的超声波的检测.这种传感器的特点是能够精确地检测由固体中传播的超声波产生的微弱振动.当超声波信号导致反射器振动时,干涉仪的输出光强度受到了超声信号的调制.通过检测干涉仪的输出光强度,并利用Fourier变换,测得了超声信号的振幅和频率.对传感系统的位相调制特性进行了仿真,并对实验结果进行了分析,表明该系统可用于固体中声发射的频率特征识别.

This paper proposes a non-contact optical fiber supersonic sensor based on a Michelson interferometer to accurately detect the faint vibrations produced by ultrasonic waves propagating in a solid body. When an optical reflector on the solid body is vibrated by ultrasonic wave signals, the output optical intensity of the interferometer is modulated by the supersonic signals. The amplitude and frequency of ultrasonic signals are obtained from the output optical intensity of the interferometer by using Fourier transform. Phase-modulation characteristics of an optical fiber sensor system were simulated. The experiment results were analyzed, indicating that the system can be used to identify the frequency characteristics of acoustic emissions.