当前位置: X-MOL 学术Eng. Res. Express › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Multi-tonal subwavelength metamaterial for absorption and amplification of acoustic and ultrasonic waves
Engineering Research Express Pub Date : 2021-05-13 , DOI: 10.1088/2631-8695/abfe1c
Marco Boccaccio , Gian Piero Malfense Fierro , Fabrizo Bucciarelli , Michele Meo

In this work, an acousto-ultrasound metamaterial-based concept is proposed to achieve high multi-tonal sound absorption at specific design frequencies and their multiple harmonics, which generally requires large and complex systems. This structure can be deployed to improve the performance of air-coupled nonlinear acoustic/ultrasound imaging by filtering unwanted fundamental ultrasound responses while amplifying high order harmonics, since nonlinear ultrasonic experiments generally necessitate advanced signal processing tools digital and pass-band filters to highlight nonlinear features. The structure proposed is an Archimedean inspired spiral cavity metamaterial with a thickness of 1/62 wavelength to achieve high multi-tonal sound absorption performances at a design frequency and the multiple harmonics. The same geometrical configuration can also be used to filter a fundamental design excitation frequency f0 and amplify second harmonic of the desired excitation frequencies, 2f0. An analytical model was developed to optimise the sound absorption and amplification frequencies of the structure with a design frequency of 690 Hz, by matching the geometrical parameters with the resonance and antiresonance mechanisms of the system. Additionally, a parallel arrangement of two Archimedean-inspired spirals is also analytically and experimentally proposed, in order to achieve harmonic absorptions at the resonant frequency of each subsystem (i.e. f01=850 Hz, f02=950 Hz). Furthermore, acoustic impedance analyses have been analytically conducted in order to physically explain all the resonance and antiresonance mechanism occurring with the proposed structures. Experimental investigations show that the proposed 3D printed metamaterial-based structures are capable to achieve multi-tonal high absorption peaks (above 90%) at the fundamental frequency f0 and odd harmonics (3f0, 5f0, etc) and sound amplification of the even harmonics (2f0 and 4f0). The results show good correlation between the predicted model and experimental results, and thus the sub-wavelength metamaterial provides promising potential for controlling and achieving high level sound absorption at low frequencies and enhancing accuracy of nonlinear ultrasound imaging applications.



中文翻译:

用于声波和超声波吸收和放大的多色调亚波长超材料

在这项工作中,提出了一种基于声超声超材料的概念,以在特定设计频率及其多次谐波下实现高多音调吸声,这通常需要大型复杂的系统。这种结构可用于通过过滤不需要的基本超声响应同时放大高次谐波来提高空气耦合非线性声学/超声成像的性能,因为非线性超声实验通常需要先进的信号处理工具数字和通带滤波器来突出非线性特征. 所提出的结构是一种受阿基米德启发的螺旋腔超材料,其厚度为 1/62 波长,以在设计频率和多次谐波下实现高多音调吸声性能。0并放大所需激励频率 2f 0 的二次谐波。通过将几何参数与系统的共振和反共振机制相匹配,开发了一个分析模型,以优化设计频率为 690 Hz 的结构的吸声和放大频率。此外,还通过分析和实验提出了两个阿基米德螺旋的平行排列,以便在每个子系统的谐振频率(即 f 01 =850 Hz,f 02)下实现谐波吸收=950 赫兹)。此外,声阻抗分析已经进行了分析,以从物理上解释所提出的结构发生的所有共振和反共振机制。实验研究表明,所提出的基于 3D 打印的超材料结构能够在基频 f 0和奇次谐波(3f 0、5f 0等)处实现多音调高吸收峰(90% 以上)和声音放大。偶次谐波(2f 0和 4f 0)。结果表明预测模型与实验结果之间具有良好的相关性,因此亚波长超材料为控制和实现低频下的高水平吸声以及提高非线性超声成像应用的准确性提供了广阔的前景。

更新日期:2021-05-13
down
wechat
bug