A Miniaturized Low-Frequency FBG Accelerometer Based on Symmetrical Cantilever Beam

Real-time monitoring of vibration characteristics of large-scale engineering structures such as buildings, bridges, and dams is important for research in structural health monitoring and other fields. Aiming at the key problem that the characteristic index and miniaturization of the existing fiber Bragg grating (FBG) accelerometer with a cantilever beam cannot be considered simultaneously, a miniaturized low-frequency FBG accelerometer with a symmetrical cantilever beam is proposed. Using formula derivation and analysis system (ANSYS) simulation software, the structural parameters of the sensor are optimized and simulated for analysis. According to the simulation results, the real sensor is made. Finally, the sensor performance is tested. The results show that the natural frequency of the sensor is about 72 Hz, which can be used to monitor vibration signals in the frequency range of 8–52 Hz. The sensitivity of the sensor is about 681.7 pm/g, and the resistance to transverse interference is less than 4.9%. Its volume is only 6.48 cm3, which is much smaller than that of an FBG accelerometer of the same kind. The research results provide a reference for the development of an FBG accelerometer of the same type.