Functionally Graded Phononic Crystals with Broadband Gap for Controlling Shear Wave Propagation

Abstract

Metamaterials that can be used in manipulating wave propagation have been shown in previous research. However, existing methods for controlling the propagation of shear waves remain a challenge. By combining the principle of wave destructive interference and the design concept of the gradient-index phononic crystals, here new functionally graded phononic crystals with broadband gap for controlling shear wave propagation are presented. The proposed functionally graded phononic crystals are formed by an array of unit cells with different topological geometries, where the topological geometries of the unit cell are tailored to obtain the frequency bandgap guided by the wave destructive interference. Meanwhile, the frequency bandgap with a target width is obtained by combining the design concept of the gradient-index phononic crystals. This work presents an approach to control the propagation of shear waves, and the advantages of the method reported in this work can be useful in engineering applications, such as bridges, railways, and buildings.