A Tunable Planar Acoustic Waveguide Based on Non-Uniform Period Thermal Fields

作     者：Zhou, Xiao-Liang Yang, Shuai Li, Jin-Rong Bian, Zu-Guang Shi, Ying-Li 

作者机构：China Academy of Space Technology Hangzhou Institute Hangzhou310012 China School of Aeronautics and Astronuatics Zhejiang University Hangzhou310027 China School of Civil Engineering and Architecture Anyang Normal University Anyang455000 China School of Civil Engineering and Architecture Zhejiang University of Science and Technology Hangzhou310023 China  Chengdu610054 China 

出 版 物：《SSRN》 

年 卷 期：2023年

核心收录：

主　　题：Energy gap 

摘      要：Elastic wave metamaterials, such as phononic crystals (PnCs) always composed of several materials in terms of periodical structures, possess unique acoustic characteristic which can exhibit outstanding performance in forbidding wave propagation with some specific frequencies. In the present paper, due to the thermal sensitivity of thermally induced shape memory polymers (SMP) and period thermal fields, a tunable planar acoustic metamaterial which is constituent homogeneous is proposed and designed to realize the function of waveguides. A thin plate model composed of homogenous thermally induced SMP and adhered with a series of metallic films at the top boundary which plays the role of local heating sources is established. The homogenous plate can be transferred into acoustic metamaterial once the non-uniform period thermal fields is imported. Based on Fourier law of heat conduction and finite element method (FEM), a two-dimensional numerical model via COMSOL Multiphysics is carried out to perform the in-plane mode band structures and transmission spectra. The results show that the band gap will be effectively opened and change obviously as the injected heat flux increases. Furthermore, band structures of 7×1 supercell with thermal defect is performed to reveal the design guideline of waveguides which is supposed to be the basis of line-type and L-type waveguides. The tunable characteristic of waveguides based on thermal fields with thermal defects are also discussed. These results may pave a new avenue for the design of tunable acoustic metamaterial composed of thermal sensitive material which own a prospect to be applied in area of acoustic waveguides. © 2023, The Authors. All rights reserved.