Fiber bragg grating accelerometer based on asymmetric shaped flexible hinge structure

Abstract

To achieve real-time health monitoring in civil engineering, a FBG acceleration sensor with asymmetric shaped flexible hinge structure is proposed. Combined with the theoretical analysis, the expressions of resonance frequency and sensitivity are deduced, and the effects of the structural parameters of the sensor on the resonance frequency and sensitivity are analyzed and simulated. Based on the optimization results, a fiber Bragg grating acceleration sensor was designed and fabricated. The amplitude-frequency response, linear sensitivity response, and lateral anti-interference ability were tested experimentally. The experimental data shows a sensor resonance frequency of 350 Hz, a sensitivity of 90.96 pm/g, and a linear correlation of 99.59%. These results closely align with the theoretical predictions of a resonance frequency of 344 Hz, and a sensitivity of 98 pm/g, confirming the accuracy of the sensor's theoretical analysis.The transverse interference immunity of the sensor is 3.7%, and an operating frequency band of 10–250 Hz. It indicates that the sensor is promising for medium and low frequency vibration measurement.