A dual oblique wing-based low-frequency FBG accelerometer.

• This accelerometer principally consists of a pair of identical mass blocks, a pair of identical inclined cantilever beams, a pair of identical fixing blocks, a pair of identical columns, and a base. • The natural frequency of this accelerometer is 46 Hz, which has good flatness in the frequency range of 0.1 to 28 Hz. • Static stress analysis and modal simulation analysis using ANSYS. • Built a low-frequency vibration testing system consisting of a low-frequency vibration system and an optical fiber sensing system. • The signal of the time series is transformed into a fast Fourier transform using the periodogram method. The low-frequency vibration measurement technology is significant in energy exploration, aerospace, geophysical activities, health monitoring of large engineering structures, etc. A low-frequency FBG accelerometer based on a dual oblique wing is proposed to address the issue of difficulty in accurately measuring low-frequency vibration signals in current fiber Bragg grating accelerometers. Firstly, the structure of this accelerometer was theoretically analyzed and dimension-optimized. Secondly, the static stress analysis and modal simulation analysis are carried out, and the accelerometer is developed. Finally, it is fixed on the vibration table, and the low-frequency vibration test system is built to test the performance. The experimental results show that the natural frequency of the accelerometer is 46 Hz, the working frequency band is 0.1–28 Hz, the sensitivity is 55.6 pm/g, the dynamic range is 48.94 dB, and the resistance to transverse interference of less than 5.62 %. The accelerometer designed in this paper provides a new idea for low-frequency vibration signal measurement. [ABSTRACT FROM AUTHOR]