Study on Band-Gap Characteristics of 2D Hierarchical Phononic Crystal

Recently, phononic crystals have attracted a wide attention. Many potential existences of phononic bandgaps have been investigated, which can be used to manipulate the propagation of acoustic/elastic waves. In the current work, a two-dimensional (2D) phononic diamond crystal is proposed, with a hierarchical periodicities and two-stage band-gaps. The proposed structure is modeled by the finite element method and calculated by the COMSOL Multiphysics software. According to the Bloch theory, the band-gaps of the structure are calculated by applying the Floquet boundary conditions. This structure represents full and directional band-gaps which is different from the one-dimensional periodic structure.