FBG传感器和电阻应变仪的振动监测特性

将光纤布拉格光栅（FBG）传感器和电阻应变片固定在等强度梁上，研究了两种传感器的振动监测性能，总结比较了其优缺点。通过固定在等强度梁末端的电机来产生振动，测试了FBG 传感器和电阻应变片监测到随时间变化的振动信号，并分析了振动信号经傅里叶变换（FFT）的频谱图。实验结果表明，FBG 传感器和电阻应变片监测到振动信号的时域图基本一致，但是FBG 传感器监测到振动信号经FFT 变换的频谱图出现较明显的二次谐波和三次谐波，电阻应变仪监测到的频谱图出现的谐波较弱。在实验中还观察到，在有电磁干扰情况下，电阻应变仪监测不到振动信号，而FBG 传感器正常工作，不受电磁干扰。

Vibration detection characteristics of FBG sensor and resistance strain gauge

Fiber Bragg grating (FBG) sensor and resistance strain gauge sensor were fixed on the uniform strength beam. Vibration detection characteristics of two kinds of sensors were investigated. The advantage and disadvantage of two kinds of sensors were compared. Vibration was caused by a motor which was fixed at the end of uniform strength beam. The vibration signal in time domain was measured, which was monitored by FBG sensor and resistance strain gauge sensor simultaneously, and the frequency spectrum was analyzed from the vibration curve through FFT. The results show that the vibration graph monitored by FBG sensor is consistent with the vibration graph monitored by resistance strain gauge sensor. But the frequency spectrum monitored by FBG sensor has second harmonic and third harmonic obviously. The frequency spectrum monitored by resistance strain gauge sensor has weak subharmonic. The experiment investigation also indicates that the vibration signal can not be monitored by resistance strain gauge under the electromagnetic interference conditions, but can be monitored by FBG sensor.