Localization of Lamb wave source with a single transmitter-receiver combination by elastic metamaterials

Abstract

Many nondestructive testing (NDT) and structural health monitoring (SHM) systems utilize Lamb wave transducer arrays for identification and localization of scattering wave sources. A large number of transducers are usually required during array signal processing and source localization, which increases hardware cost and reduces system reliability. To overcome this limitation, a metamaterial structure is designed in this study to realize source localization with a single transmitter-receiver combination. The basic design principle is the utilization of local resonators to customize propagation characteristics of Lamb waves. In particular, amplitude-frequency modulation and velocity dispersion are customized during metamaterial design. Uncorrelated amplitude-frequency modulation is extracted from signal frequency spectrum for orientation identification. Velocity dispersion is extracted from signal time-frequency spectrum for distance evaluation. After orientation