Piezoelectric wafer active sensors for in situ ultrasonic‐guided wave SHM

Abstract

A B S T R A C T In situ structural health monitoring aims to perform on-demand interrogation of the structure to determine the presence of service-induced damage and defects using nondestructive evaluation ultrasonic wave methods. Recently emerged piezoelectric wafer active sensors (PWAS) have the potential to significantly improve damage detection and health monitoring. PWAS are low-profile transducers that can be permanently attached onto the structure or inserted in between composite laminates, and can perform structural damage detection in thin-wall structures using guided wave methods (Lamb, Rayleigh, SH, etc.). This paper describes the analytical and experimental work of using PWAS-guided waves for in situ structural damage detection on thin-wall structures. We begin with reviewing the guided wave theory in plate structures and PWAS principles. The mechanisms of Lamb wave excitation and detection using PWAS is presented. Subsequently, we address in turn the use of PWAS to generate Lamb waves for damage (cracks and corrosion) detection in metallic structures. Pulse-echo, pitch-catch, phased array and time reversal methods are illustrated demonstrating that PWAS Lamb-waves techniques are suitable for damage detection and structural health monitoring. The last part of the paper treats analytically and experimentally PWAS excitation and tuning in composite materials. The research results presented in this paper show that in situ SHM methodologies using PWAS transducers hold the promise for more efficient, effective and timely damage detection in thin-wall structures.

Zinc oxide nanoparticle-polymeric thin films for dynamic strain sensing

“…Piezoelectric transducers such as piezo-ceramic lead zirconate titanate (PZT) and poly(vinylidene fluoride) (PVDF) piezo-polymers have been widely adopted for sensing [1], actuation [2], control [3], and energy harvesting [4]. Unique to piezoelectric materials is their inherent ability to simultaneously serve as sensors and actuators.…”

A structural health monitoring system with ultrasonic MEMS transducers

“…However, the coupling efficiency of these films is too low (~25%) to be considered as a viable alternative to the bulk PZTs. Additionally, piezoelectric wafer active sensors (PWASs) have been investigated as an alternative [3,14,15]. Although PWAS operation is based on the piezoelectricity concept, its operation principle is quite different.…”

“…Although PWAS operation is based on the piezoelectricity concept, its operation principle is quite different. These non-resonant devices are permanently bonded and transfer the waves directly to the structure via in-plane strain coupling [15]. However, there are inherent limitations of the PWAS concept.…”

Rapid localization of damage using a circular sensor array and Lamb wave based triangulation

“…An analytical, numerical and experimental analysis on Lamb wave propagation in a narrow beam and plate with a notch simulating a damage and the effect of such damage on different Lamb wave modes was reported in Refs. [5][6][7].…”