Embedded NDT with piezoelectric wafer active sensors

Abstract

Piezoelectric wafer active sensors (PWAS) are lightweight and inexpensive enablers for a large class of embedded NDT applications such as structural health monitoring (SHM). After a brief review of PWAS physical principles and basic modeling, the paper considers several ultrasonics SHM methods such as: (a) embedded guided-wave ultrasonics, i.e., pitch-catch, pulse-echo, phased arrays; (b) high-frequency modal sensing, i.e., the electro-mechanical (E/M) impedance method; (c) passive detection, i.e., acoustic emission and impact detection. Recent developments in PWAS phased arrays are presented and discussed. The paper ends with conclusions and suggestions for further work to achieve the full potential of this promissing new technology. © RILEM 2013.