基于悬臂梁结构的光纤布拉格光栅振动传感器频响特性研究OA

To reduce the cost of current engineering structural health monitoring and real-time measurement,the influence law of the packaging structure of fiber Bragg grating vibration sensors on their characteristic frequencies is studied.A simple fiber Bragg grating vibration sensing system is designed and constructed by adopting tunable laser and photodetector.Five groups of structures with different cantilever beam lengths ranging from 10 mm to 30 mm are adopted in experiments.Vibration data of the sensor within the frequency range of 50～800 Hz are collected by a single-chip microcomputer,and the real-time acceleration output of the vibration exciter is calibrated by a piezoelectric accelerometer simultaneously.It is shown by experimental results that the natural frequency and sensitivity of the sensor can be effectively regulated by changing the cantilever beam length.With the increase of cantilever beam length,the low-frequency sensitivity is improved obviously,and the sensitivity of the 30 mm cantilever beam is about 2.4 times that of the 10 mm one.A good linear relationship of the system is verified through experiments,and a flexible solution is provided for low-cost vibration monitoring scenarios.