Design of an S-type elastic composite fiber optic vibration sensor

This article focuses on the background of real-time safety monitoring of low-frequency vibration signals generated in key parts of large-scale engineering such as water turbine units. A fiber optic grating vibration sensor based on S-shaped elastomers and wedge-shaped beams as elastic sensitive components is designed, and an elastic theoretical model of its vibration sensitive component is established. The finite element numerical model is used to optimize the parameters of the vibration sensitive component and conduct static analysis. An experimental platform is built to conduct vibration performance related tests. The research shows that the designed fiber optic grating vibration sensor has functions such as ultra-low frequency pickup, high sensitivity feedback, and temperature adaptive compensation. The pickup frequency of the sensor can be as low as 0.5Hz, with a pickup sensitivity of up to 789pm/g and a nonlinear error of less than 2%. The sensor group can be formed by using wavelength division multiplexing technology to form a quasi distributed chain. Network monitoring, it can solve the technical problem of achieving ultra-low frequency vibration safety monitoring in large projects such as water turbine units under strong electromagnetic interference.