Steering and focusing of fundamental shear horizontal guided waves in plates by using multiple-strip metasurfaces

¹ LTCS and College of Engineering, Peking University - Beijing 100871, China
² Center for Applied Physics and Technology, Peking University - Beijing, China

^(a) lifaxin@pku.edu.cn

Received: 9 June 2019
Accepted: 27 August 2019

Abstract

We proposed a metasurface consisting of multiple parallel strips with varied widths which can steer and focus the fundamental shear horizontal (SH₀) wave in plates. Firstly, the group velocity of the quasi-SH₀ wave in different-width strips was calculated. Then, a multiple-strip metasurface was designed which was realized by through-thickness grooving in an aluminum plate. Finite-element simulations show that this metasurface can steer the SH₀ wave to a prescribed angle. Later, experiments were conducted in which thickness-shear (d₁₅) piezoelectric strips were used as SH₀ wave exciters and receivers, and experimental results well reproduced the simulation results. Finally, another multiple-strip metasurface was designed to focus the SH₀ wave at a designated point. Both simulations and experiments were conducted, and results validated the proposed design. This work may provide guidance for the design of SH wave metasurfaces.