Application of Piezoelectric Wafer Active Sensors for Elastic Guided Wave Excitation and Detection in Structural Health Monitoring Systems for Elongated Constructions

Abstract

At present, technologies for continuous ultrasonic monitoring of the state of extended structures using elastic guided waves excited and measured by an array of piezoelectric wafer active sensors are being actively developed. Guided waves interact with inhomogeneities (defects) of any nature, revealing their presence by reflected and scattered waves arising due to diffraction, while a change in their characteristics indicates the degradation of the strength properties of the material during operation. Based on measurements taken on laboratory samples, we demonstrate the capabilities of piezoelectric wafer active sensors to generate probing signals of various types and vary their amplitude-frequency characteristics in a wide frequency range. Mathematical modeling of wave processes is carried out within the framework of an integral approach based on an explicit integral and asymptotic representation of excited waves through the Fourier symbol of the Green’s matrix of the waveguide structure under consideration. The experimental measurements confirm the applicability of the simplified model developed on this basis for the two-mode excitation range of fundamental Lamb waves.