【作者】 陈猛； 刘宇； 杨洮； 肖伯雅； 姜恒； 王育人；

【Author】 CHEN Meng;LIU Yu;YANG Tao;XIAO Bo Ya;JIANG Heng;WANG Yu Ren;Key Laboratory of Microgravity,Institute of Mechanics,Chinese Academy of Sciences;University of Chinese Academy of Sciences;

【机构】 中国科学院力学研究所微重力重点实验室； 中国科学院大学；

【摘要】 自相似分形结构是一种典型的空间折叠构型,其包含多重振动模态,会产生多重亚波长带隙。本文以具有曲线通道的二维自相似分形结构为基础,将其进行旋转耦合,设计了对称性较好、具有Mie共振特性的二维自相似分形结构。计算结果表明在分形结构中存在亚波长的Dirac点,随着分形阶数增加Dirac点数目增加,且向低频移动。在Dirac点附近表现出近零质量密度特性,在特定频率处声波能够实现超常传输,在复杂结构中仍具有较好的声波传输特性,这为奇异声学器件设计提供了新的技术手段。更多还原

【Abstract】 Self-similar fractal structure is a typical spatial folding configuration,which contains multiple vibration modes and generates multiple subwavelength band gaps.Based on the two-dimensional self-similar fractal structure with curved channels,this paper uses rotational coupling to design a two-dimensional self-similar fractal structure with good symmetry and Mie resonance characteristics.The calculation results show that there are sub-wavelength Dirac points in the fractal structure.With the increase of the fractal order,the number of Dirac points increases and moves to low frequencies.Near the Dirac point,it exhibits near-zero mass density characteristics.Acoustic waves can achieve extraordinary transmission at specific frequencies,and still have good acoustic wave transmission characteristics in complex structures.This provides new technical means for the design of singular acoustic devices.更多还原