Sound absorption of a new oblique-section acoustic metamaterial with nested resonator

This study designs and investigates high-efficiency sound absorption of new oblique-section nested resonators. Impedance tube experiment results show that different combinations of oblique-section nest resonators have tunable low-frequency bandwidth characteristics. The sound absorption mechanism is due to air friction losses in the slotted region and the sample structure resonance. The acousto-electric analogy model demonstrates that the sound absorption peak and bandwidth can be modulated over an even wider frequency range by changing the geometric size and combinations of structures. The proposed structure can be easily fabricated and used in low-frequency sound absorption applications.

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Realizing high-efficiency low frequency sound absorption of underwater meta-structures by acoustic siphon effect

Modern Physics Letters B ◽

10.1142/s021798492150319x ◽

2021 ◽

pp. 2150319

Author(s):

Li Bo Wang ◽

Cheng Zhi Ma ◽

Jiu Hui Wu ◽

Chong Rui Liu

Keyword(s):

Absorption Coefficient ◽

Sound Absorption ◽

High Efficiency ◽

Physical Mechanism ◽

Low Frequency ◽

Area Ratio ◽

Underwater Acoustic ◽

Element Simulation ◽

Average Absorption Coefficient ◽

New Perspective

The underwater acoustic siphon effect is proposed in this work, which aims to reveal the basic physical mechanism of high-efficiency sound absorption in meta-structures composed of multiple detuned units. Furthermore, the influence of the area ratio on the underwater acoustic siphon effect is then investigated by finite element simulation (FES) and theoretical calculation. On this basis, a meta-structure with the maximum absorption coefficient of almost 100% and average absorption coefficient of 80% at 600–1400 Hz is achieved. The underwater acoustic siphon effect could provide a better understanding of high-efficiency sound absorption and offer a new perspective in controlling underwater noises.

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Hybrid acoustic metamaterial as super absorber for broadband low-frequency sound

Scientific Reports ◽

10.1038/srep43340 ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 58

Author(s):

Yufan Tang ◽

Shuwei Ren ◽

Han Meng ◽

Fengxian Xin ◽

Lixi Huang ◽

...

Keyword(s):

Energy Dissipation ◽

Absorption Coefficient ◽

Sound Absorption ◽

Low Frequency ◽

Functional Materials ◽

Theoretical Method ◽

Acoustic Metamaterials ◽

Mechanical Stiffness ◽

Acoustic Metamaterial ◽

Frequency Sound

Abstract A hybrid acoustic metamaterial is proposed as a new class of sound absorber, which exhibits superior broadband low-frequency sound absorption as well as excellent mechanical stiffness/strength. Based on the honeycomb-corrugation hybrid core (H-C hybrid core), we introduce perforations on both top facesheet and corrugation, forming perforated honeycomb-corrugation hybrid (PHCH) to gain super broadband low-frequency sound absorption. Applying the theory of micro-perforated panel (MPP), we establish a theoretical method to calculate the sound absorption coefficient of this new kind of metamaterial. Perfect sound absorption is found at just a few hundreds hertz with two-octave 0.5 absorption bandwidth. To verify this model, a finite element model is developed to calculate the absorption coefficient and analyze the viscous-thermal energy dissipation. It is found that viscous energy dissipation at perforation regions dominates the total energy consumed. This new kind of acoustic metamaterials show promising engineering applications, which can serve as multiple functional materials with extraordinary low-frequency sound absorption, excellent stiffness/strength and impact energy absorption.

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New acoustical technology of sound absorption based on reverse horn

Modern Physics Letters B ◽

10.1142/s0217984916504030 ◽

2016 ◽

Vol 30 (34) ◽

pp. 1650403 ◽

Cited By ~ 2

Author(s):

Yong Yan Zhang ◽

Jiu Hui Wu ◽

Song Hua Cao ◽

Pei Cao ◽

Zi Ting Zhao

Keyword(s):

High Frequency ◽

Sound Absorption ◽

Mechanical Energy ◽

Low Frequency ◽

Acoustic Energy ◽

Absorption Mechanism ◽

Structure Changes ◽

Potential Applications ◽

Energy Focusing ◽

The One

In this paper, a novel reverse horn’s sound-absorption mechanism and acoustic energy focusing mechanism for low-frequency broadband are presented. Due to the alternation of the reverse horn’s thickness, the amplitude of the acoustic pressure propagated in the structure changes, which results in growing energy focused in the edge and in the reverse horn’s tip when the characteristic length is equal to or less than a wavelength and the incident wave is compressed. There are two kinds of methods adopted to realize energy dissipation. On the one hand, sound-absorbing materials are added in incident direction in order to overcome the badness of the reverse horn’s absorption in high frequency and improve the overall high-frequency and low-frequency sound-absorption coefficients; on the other hand, adding mass and film in its tip could result in mechanical energy converting into heat energy due to the coupled vibration of mass and the film. Thus, the reverse horn with film in the tip could realize better sound absorption for low-frequency broadband. These excellent properties could have potential applications in the one-dimensional absorption wedge and for the control of acoustic wave.

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Deep subwavelength acoustic metamaterial for low-frequency sound absorption

EPL (Europhysics Letters) ◽

10.1209/0295-5075/118/44002 ◽

2017 ◽

Vol 118 (4) ◽

pp. 44002 ◽

Cited By ~ 11

Author(s):

Yufan Tang ◽

Fengxian Xin ◽

Lixi Huang ◽

Tianjian Lu

Keyword(s):

Sound Absorption ◽

Low Frequency ◽

Acoustic Metamaterial ◽

Frequency Sound

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Structural Design and Sound Absorption Properties of Nitrile Butadiene Rubber-Polyurethane Foam Composites with Stratified Structure

Polymers ◽

10.3390/polym10090946 ◽

2018 ◽

Vol 10 (9) ◽

pp. 946 ◽

Cited By ~ 7

Author(s):

Xueliang Jiang ◽

Zhijie Wang ◽

Zhen Yang ◽

Fuqing Zhang ◽

Feng You ◽

...

Keyword(s):

Polyurethane Foam ◽

Structural Design ◽

Sandwich Structure ◽

Sound Absorption ◽

Low Frequency ◽

Thickness Ratio ◽

Butadiene Rubber ◽

Absorption Mechanism ◽

Nitrile Butadiene Rubber ◽

Absorption Performance

Sound absorbing composites with stratified structures, including double-layer and sandwich structures, were prepared through the combination of nitrile butadiene rubber (NBR) and polyurethane foam (PUFM). The effects of the thickness ratio of layers, different stratified structures and the variety of fillers on the sound absorption performance of the NBR-PUFM composites and the sound absorption mechanism were studied. The results show that the NBR-PUFM composite with a sandwich structure and thickness ratio of 1:8:1 displays good sound absorption, which could be improved further by adding fillers. Because the airflow resistivity, resonance absorption, interface dissipation and interface reflection were combined organically in the sandwich structure, the composites show excellent low-frequency sound absorption performance. Moreover, the composite also has advantages in cost and functionalization aspects.

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Micro-perforated acoustic metamaterial with honeycomb-corrugation hybrid core for broadband low frequency sound absorption

Acta Physica Sinica ◽

10.7498/aps.67.20181368 ◽

2018 ◽

Vol 67 (23) ◽

pp. 234302

Author(s):

Zhang Feng-Hui ◽

Tang Yu-Fan ◽

Xin Feng-Xian ◽

Lu Tian-Jian

Keyword(s):

Sound Absorption ◽

Low Frequency ◽

Acoustic Metamaterial ◽

Frequency Sound

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Preparation and Low Frequency Sound Absorption Properties of Silicate Composite Material

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.482-484.1338 ◽

2012 ◽

Vol 482-484 ◽

pp. 1338-1342 ◽

Cited By ~ 1

Author(s):

Long Gui Peng ◽

Guang Cheng Zhang ◽

Xing Guo Yu ◽

Ying Li

Keyword(s):

Composite Material ◽

Absorption Coefficient ◽

Sound Absorption ◽

High Efficiency ◽

Low Frequency ◽

Thin Wall ◽

Absorption Properties ◽

Cement Ratio ◽

Water Cement Ratio ◽

Frequency Sound

The silicate based low frequency sound absorption composite material was prepared with powdery polymethacrylimide (PMI) foam as filler. The effects of the amounts of PMI and pore-forming agent, and water-cement ratio on sound absorption properties of composite material were researched. Sound absorption coefficient was characterized by standing wave tube, and micro structure of composite material was analyzed by scanning electron microscope. The results show that: when the amounts of PMI and pore-forming agent are 2.5wt% and 0.04wt%, respectively, and water cement ratio is 0.55, the average value of the absorption coefficient on the sound （≤1000Hz）can up to 0.35. Resonating sound absorption structure formed by micro pore of the silicate and thin wall cavity of PMI in composite materials is beneficial to high efficiency absorption to low frequency sound.

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