Laboratory for Bio-inspired, Bionic, Nano, Meta Materials and Mechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, 38123 Trento, Italy.
School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
Philos Trans A Math Phys Eng Sci. 2022 Nov 28;380(2237):20210389. doi: 10.1098/rsta.2021.0389. Epub 2022 Oct 10.
The design of structures that can yield efficient sound insulation performance is a recurring topic in the acoustic engineering field. Special attention is given to panels, which can be designed using several approaches to achieve considerable sound attenuation. Previously, we have presented the concept of thickness-varying periodic plates with optimized profiles to inhibit flexural wave energy propagation. In this work, motivated by biological structures that present multiple locally resonant elements able to cause acoustic cloaking, we extend our shape optimization approach to design panels that achieve improved acoustic insulation performance using either thickness-varying profiles or locally resonant attachments. The optimization is performed using numerical models that combine the Kirchhoff plate theory and the plane wave expansion method. Our results indicate that panels based on locally resonant mechanisms have the advantage of being robust against variation in the incidence angle of acoustic excitation and, therefore, are preferred for single-leaf applications. This article is part of the theme issue 'Wave generation and transmission in multi-scale complex media and structured metamaterials (part 2)'.
在声学工程领域，设计能够产生高效隔音性能的结构是一个反复出现的主题。特别关注的是面板，可以使用几种方法来设计，以实现相当大的声音衰减。以前，我们提出了厚度变化的周期性板的概念，具有优化的轮廓，以抑制弯曲波能量的传播。在这项工作中，受具有多个局部共振元件的生物结构的启发，这些元件能够引起声隐身，我们扩展了我们的形状优化方法，以设计使用厚度变化轮廓或局部共振附件来实现改进隔音性能的面板。优化是使用结合了 Kirchhoff 板理论和平面波展开方法的数值模型进行的。我们的结果表明，基于局部共振机制的面板具有对声激励入射角变化的稳健性优势，因此，更适合单叶应用。本文是主题为“多尺度复杂介质和结构超材料中的波产生和传输（第 2 部分）”的一部分。
