2D underwater acoustic metamaterials incorporating a combination of particle-filled polyurethane and spiral-based local resonance mechanisms

2019 ◽  
Vol 220 ◽  
pp. 1-10 ◽  
Author(s):  
Haibin Zhong ◽  
Yinghong Gu ◽  
Bin Bao ◽  
Quan Wang ◽  
Jiuhui Wu
Keyword(s):  
Acoustic Metamaterials ◽  
Underwater Acoustic ◽  
Local Resonance

Tunable underwater acoustic metamaterials via quasi-Helmholtz resonance: From low-frequency to ultra-broadband

2021 ◽  
Vol 118 (7) ◽  
pp. 071904
Author(s):  
Mingyu Duan ◽  
Chenlei Yu ◽  
Fengxian Xin ◽  
Tian Jian Lu
Keyword(s):  
Low Frequency ◽  
Acoustic Metamaterials ◽  
Underwater Acoustic ◽  
Helmholtz Resonance

scholarly journals A Composite Perforated Partitioned Sandwich Panel With Corrugation for Underwater Low-Frequency Sound Absorption

2021 ◽  
Vol 7 ◽  
Author(s):  
Junyi Wang ◽  
Jiaming Hu ◽  
Yun Chen
Keyword(s):  
Acoustic Wave ◽  
Composite Structure ◽  
Sound Absorption ◽  
Low Frequency ◽  
Propagation Loss ◽  
Sound Waves ◽  
Acoustic Metamaterials ◽  
Underwater Sound ◽  
Underwater Acoustic ◽  
Frequency Sound

Underwater acoustic wave absorption and control play an important role in underwater applications. Various types of underwater acoustic metamaterials have been proposed in recent years with the vigorous development of acoustic metamaterials. Compared with airborne sound, underwater sound waves have a longer wavelength and much smaller propagation loss, making them more difficult to control. In addition, given that the acoustic impedance of water is much greater than that of air, numerous conventional materials and structures are not suited to underwater use. In this paper, we propose a composite structure based on an excellent broadband low-frequency sound absorber of air using aluminum mixed with rubber. Our composite structure possesses broadband low-frequency (<1,000 Hz) sound absorption underwater, omnidirectional high sound absorption coefficient under the oblique incidence (0–75°), and pressure resistance. It has promising applications for underwater acoustic wave control and contributes to the design of underwater acoustic metamaterials.

scholarly journals Experimental and Numerical Assessment of Local Resonance Phenomena in 3D-Printed Acoustic Metamaterials

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
D. Roca ◽  
T. Pàmies ◽  
J. Cante ◽  
O. Lloberas-Valls ◽  
J. Oliver
Keyword(s):  
Acoustic Waves ◽  
Unit Cell ◽  
Material Structure ◽  
Cell Design ◽  
Acoustic Metamaterials ◽  
Local Resonance ◽  
Resonance Phenomena ◽  
Resonance Frequencies ◽  
Characteristic Wavelength ◽  
3D Printed

Abstract The so-called locally resonant acoustic metamaterials (LRAMs) are a new kind of artificially engineered materials capable of attenuating acoustic waves. As the name suggests, this phenomenon occurs in the vicinity of internal frequencies of the material structure and can give rise to acoustic bandgaps. One possible way to achieve this is by considering periodic arrangements of a certain topology (unit cell), smaller in size than the characteristic wavelength. In this context, a computational model based on a homogenization framework has been developed from which one can obtain the aforementioned resonance frequencies for a given LRAM unit cell design in the sub-wavelength regime, which is suitable for low-frequency applications. Aiming at validating both the proposed numerical model and the local resonance phenomena responsible for the attenuation capabilities of such materials, a 3D-printed prototype consisting of a plate with a well selected LRAM unit cell design has been built and its acoustic response to normal incident waves in the range between 500 and 2000 Hz has been tested in an impedance tube. The results demonstrate the attenuating capabilities of the proposed design in the targeted frequency range for normal incident sound pressure waves and also establish the proposed formulation as the fundamental base for the computational design of 3D-printed LRAM-based structures.

scholarly journals A review of underwater acoustic metamaterials

2020 ◽  
Vol 65 (15) ◽  
pp. 1396-1410
Author(s):  
Ying Cheng ◽  
Ke’an Chen ◽  
Yanni Zhang ◽  
Xiaying Hao
Keyword(s):  
Acoustic Metamaterials ◽  
Underwater Acoustic

Multi-large low-frequency band gaps in a periodic hybrid structure

2016 ◽  
Vol 30 (08) ◽  
pp. 1650116 ◽  
Author(s):  
T. Wang ◽  
M. P. Sheng ◽  
H. B. Guo
Keyword(s):  
Frequency Band ◽  
Phononic Crystal ◽  
Low Frequency ◽  
Hybrid Structure ◽  
Band Gaps ◽  
Response Analysis ◽  
Acoustic Metamaterials ◽  
Frequency Range ◽  
Local Resonance ◽  
Small Series

A hybrid structure composed of a local resonance mass and an external oscillator is proposed in this paper for restraining the elastic longitudinal wave propagation. Theoretical model has been established to investigate the dispersion relation and band gaps of the structure. The results show that the hybrid structure can produce multi-band gaps wider than the multi-resonator acoustic metamaterials. It is much easier for the hybrid structure to yield wide and low band gaps by adjusting the mass and stiffness of the external oscillator. Small series spring constant ratio results in low-frequency band gaps, in which the external oscillator acts as a resonator and replaces the original local resonator to hold the band gaps in low frequency range. Compared with the one-dimensional phononic crystal (PC) lattice, a new band gap emerges in lower frequency range in the hybrid structure because of the added local resonance, which will be a significant assistance in low-frequency vibration and noise reduction. Further, harmonic response analysis using finite element method (FEM) has been performed, and results show that elastic longitudinal waves are efficiently forbidden within the band gaps.

Sign in / Sign up

Export Citation Format

Share Document