Widening, transition and coalescence of local resonance band gaps in multi-resonator acoustic metamaterials: From unit cells to finite chains
Widening, transition and coalescence of local resonance band gaps in multi-resonator acoustic metamaterials: From unit cells to finite chains
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DOI：
10.1016/j.jsv.2021.116716
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发表时间：
2022-01-19
影响因子：
4.7
通讯作者：
Singh, T.
中科院分区：
文献类型：
--
作者：
Stein, A.;Nouh, M.;Singh, T.
声学超材料的局域共振带隙以其衰减强、频率跨度窄而著称。后者限制了实现宽带衰减的亚波长带隙的实际能力，并激发了近年来新型超材料的设计。在本文中，我们研究了声学超材料的行为，其中单元格容纳多个以不同配置堆叠的共振元件，旨在激发各种波传播剖面，否则无法实现。多谐振腔超材料的色散力学是用纯解析表达式来描述和解释这种系统的潜在动力学，包括在单位细胞水平上以及它们的有限实现的频率响应。该框架揭示了具有平行谐振腔的超材料中上下带隙边界跃迁导致带隙显着扩大的机制。该分析还说明了具有双周期超级电池的超材料能够表现出一系列色散跃迁的能力，最终导致声学和光学带的坍缩解决方案，从而实现局部共振带隙的合并，共振的消失，以及其间的许多有趣的场景。
Local resonance band gaps in acoustic metamaterials are widely known for their strong attenuation yet narrow frequency span. The latter limits the practical ability to implement subwavelength band gaps for broadband attenuation and has motivated novel metamaterial designs in recent years. In this paper, we investigate the behavior of acoustic metamaterials where unit cells house multiple resonating elements stacked in different configurations, aimed at instigating a wide array of wave propagation profiles that are otherwise unattainable. The dispersion mechanics of the multi-resonator metamaterials are developed using purely analytical expressions which depict and explain the underlying dynamics of such systems both at the unit cell level as well as the frequency response of their finite realizations. The framework reveals the mechanism behind the transition of the lower and upper band gap bounds in metamaterials with parallel resonators resulting in a significant band gap widening. The analysis also illustrates the ability of metamaterials with dual-periodic super cells to exhibit a range of dispersion transitions culminating in collapsing solutions of acoustic and optical bands, enabling a coalescence of local resonance band gaps, vanishing resonances, and a number of intriguing scenarios in between.