Bearing-based FBG acceleration sensor for low-frequency vibration measurement

Low-frequency vibration measurement is of great significance in fields such as earthquake and tsunami monitoring, large-scale structural health detection, and precision instrument manufacturing. Aiming at the difficulty of accurately extracting low-frequency microvibration signals, a kind of fiber Bragg grating (FBG) acceleration sensor combining a bearing and cantilever beam is proposed. The sensor pickup model is built, and its theoretical formula is derived. The optimization objective function of key parameters is solved by MATLAB, the simulation is carried out by ANSYS, and the sensor is developed and tested for performance. The research results indicate that the sensitivity of the sensor is 1226.6 pm/g, the natural frequency is 82 Hz, the flat response range is 0.3–57 Hz, the temperature sensitivity is 0.10 pm/℃, and the lateral interference resistance is less than 6.88 %. The study's findings serve as a guide for enhancing the capability of low-frequency FBG acceleration sensors for low-frequency vibration measurement.