A multi-cantilever beam low-frequency FBG acceleration sensor

Abstract

The acquisition of 2–50 Hz low-frequency vibration signals is of great significance for the monitoring researches on engineering seismology, bridges & dams, oil & gas exploration, etc. A multi-cantilever beam low-frequency FBG acceleration sensor is proposed against the low sensitivity that predominates in the low-frequency vibration measurement by FBG acceleration sensors. Structural parameters of the sensor is subjected to simulation analysis and optimization design using the ANSYS software; the real sensor is developed based on the simulation results in the following manner: Three rectangular of the cantilever beams are evenly arranged around the mass block at 120°to improve the sensitivity and alleviate the transverse crosstalk of sensor; in the end, a performance test is performed on the sensor. According to the research findings, the sensor, whose natural frequency is approximately 64 Hz, is applicable for monitoring the low-frequency vibration signals within the range 16–54 Hz. The sensor sensitivity is approximately $$87.955\,{\text{pm/m}}\;{\text{s}}^{ - 2}$$ 87.955 pm/m s - 2 , the linearity being greater than 99%, the transverse interference immunity being lower than 2.58%, and the dynamic range being up to 86 dB. The findings offer a reference for developing sensor of the same type and further improving the sensitivity of fiber optic acceleration sensor.

Optical fiber vibration sensor for bearing fault detection based on Sagnac interferometer

“…Compared with other sensors, optical fiber sensors have attracted more attention because of their light weight, simple structure, anti-electromagnetic interference and other characteristics. Various types of fiber sensors have been developed for vibration detections based on Fabry-Perot interferometer (FPI) [3][4][5], Mach-Zehnder interferometer (MZI) [6][7][8][9], Sagnac interferometer (SI) [10,11], multimode interferometer [12,13], fiber Bragg grating (FBG) [14,15], Michelson interferometer (MI) [16,17], etc. An optical fiber vibration sensor is multimode sandwiched between two single-mode fibers (SMFs).…”

Serially Connected Cantilever Beam-Based FBG Accelerometers: Design, Optimization and Testing

“…Zhang et al proposed a double semi-circle cantilever beam with high sensitivity and a minimum detectable frequency of 5 Hz [ 27 ]. Hong et al designed a multi-cantilever beam mainly composed of three rectangular cantilever beams with low frequency, within the range of 16–54 Hz and a sensitivity of 87.955 pm/g [ 28 ]. A low-frequency FBG accelerometer based on a polyphenylene ether (PPE) thermoplastic cantilever beam with a sensitivity of 110 pm/g and a natural frequency of 9 Hz was proposed by Hafizi et al [ 29 ].…”