Study of the Guided Wave Sensing by Hybrid Piezoelectric-FBG Approach

Abstract

In this research, analysis of ultrasonic guided wave sensing using fiber optic strain sensors based on fiber Bragg gratings (FBG) is presented. Wave excitation is based on piezoelectric transducers. Sensitivity of the FBG sensors to propagating ultrasonic waves plays an important role in the design process of SHM system based on fiber optic sensors. The presented study has experimental character. Separation of symmetric and antisymmetric modes is studied based on simultaneous sensing of the guided waves with two FBG sensors. The influence of actuation is studied for various frequencies of excitation. Moreover, influence of piezoelectric transducers with different diameters on the wave signals registered at the FBG sensors is investigated. The obtained results show significant impact of the diameter of the piezoelectric actuators on the guided waves signals registered by FBGs.