Comparative study of elastic wave sensing using piezoceramic and fiber optic FBG sensors

In this paper results of detailed analysis of phenomenon of elastic guided wave sensing using fibre optic strain sensors based on Bragg gratings (FBGs) and piezoelectric transducers (PZT) are presented. Attention in this research is focused on possibility of symmetric and antisymmetric guided wave mode sensing with the possibility of mode separation. For this purpose pairs of sensors located on the top and bottom surface is utilized. Moreover, mode index was introduced in order to distinguish fundamental symmetric and anti-symmetric wave modes. Authors compare sensitivity of elastic wave sensing performed by FBG sensor with one based on PZT. Piezoelectric transducers are very popular in applications related to elastic wave generation and sensing in structural health monitoring and on the other hand FBG strain sensors are utilized more and more in elastic wave sensing purpose. Research was conducted for the case of aluminum panel.