Topological phononic crystal plates with locally resonant elastic wave systems

In this paper, we study the topological properties of subwavelength bands in elastic phononic crystal (PC) plate hybridized with extra local resonances and analyze the band-structure evolution of a topological PC plate with local resonator using finite element method (FEM). Our structure can produce two bandgaps in the subwavelength region: one originates from the local resonator of unit cell and the other one stem from breaking the C6v symmetry of an original plate PnC in a honeycomb lattice to introduce valley pseudospins. It is found that the edge states only existed in the Bragg bandgaps and the directional spread of elastic waves can be realized in both straight and bent waveguides, and the numerical simulation in a waveguide plate perfectly agrees with the theoretical results. In addition, experimental test is used to validate theoretical and numerical approach to the design of topological waveguides. This study provides an effective approach of producing robust elastic wave topological edge modes in the subwavelength region for plate-like structure. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This paper investigates the topological properties of subwavelength bands in elastic phononic crystal (PC) plate hybridized with extra local resonances, and analyzes the band-structure evolution of a topological PC plate with local resonator using finite element method (FEM). The structure is capable of producing two bandgaps in the subwavelength region, and experimental tests validate the theoretical and numerical approach to the design of topological waveguides.