利用平面拉脹性超穎材料進行可調式聲波傳遞

Abstract

本文主要探討可調頻平面超穎材料之聲波傳遞行為。首先透過商用有限元素分析軟體進行分析模擬，針對一具拉脹性薄膜結構之超穎材料作週期性排列設定，分析其單元之能帶結構，因其結構拉脹特性，利用幾何變形將可能阻擋某些特定頻率下聲波通過，達到可調頻的效果。另外，亦透過聲學實驗觀察該特定頻率下的波傳衰減行為，並與模擬進行比較與相互映證，結果顯示該結構將能阻隔特定頻率範圍內的聲波傳遞。

A tunable planar auxetic metamaterial for controlling and filtering acoustic waves was investigated. In the study, the commercial finite element software package was utilized for numerical simulations. A planar auxetic structure was placed periodically, and its acoustic band structure was obtained. It was found that the bandages may appear in certain frequency range because of the geometric deformation of the auxetic structure. In addition, the wave attenuation behavior at a specific frequency was investigated experimentally, and the experimental results were compared with those obtained from numerical simulations. Both the numerical and experimental results showed that the planar auxetic structure is tunable for controlling the sound wave propagation and filtering the waves within a specific frequency range.