基于光纤光栅PGCD的材料冲击试验研究

Research on material impacting based on PGCD with fiber Bragg grating

光纤光栅抗电磁干扰和易于构成分布式光纤传感网络,对设备健康监测和高频应力作用下的材料力学性能测试具有独特优势。波长编码信号解调系统的频率低是制约光纤光栅传感器在高频信号环境下使用的关键问题之一,采用M-Z干涉技术,设计了一套基于相位载波(PGC)的相位解调方法的光纤光栅高频解调系统,对正弦信号激励和冲击试验产生的信号进行了测试和分析,取得了比较理想的试验结果,实现了10 kHz频率范围内高频信号的检测。

The unique merits of fiber Bragg grating, such as it is immune to electromagnetic field and easy to constitute a distributed sensors network, are effectively used for equipment health monitoring and testing mechanical characteristics of materials under high frequency stress load. The frequency of wavelength encoded signal demodulation is one of the key problems that limit the use of fiber Bragg grating sensor in high frequency signal environment. Mach-Zehnder interference technology is adopted to design a high-frequency demodulation system for fiber Bragg grating,which bases on phase generated carrier demodulation （PGCD）. With this designed demodulation system, the signals produced by sinusoidal stimulating and impact setup are measured. The experimental results are satisfied. The measurement of 10 kHz frequency is achieved.