Multi-mass synergetic coupling perforated bi-layer plate-type acoustic metamaterials for sound insulation

Thin plate-type acoustic metamaterials have the advantages of lightweight, high rigidity and adjustable parameters, showing great practical application values in sound wave control. In this paper, a type of perforated bi-layer plate-type acoustic metamaterials (PBPAM) is designed for low-frequency noise control. The sound insulation peaks can be increased by combining the perforated plate and synergetic masses, making the sound insulation performance close to the mass law at the resonant frequency. Compared to the results predicted by the mass law, a better performance of sound insulation is achieved based on the PBPAM. The effects of the structural parameters are investigated in this study. Based on the impedance tube experiments, the measured results have a good agreement with the simulated ones. This work can provide a reference for low-frequency and broadband sound insulation based on plate-type acoustic metamaterials in practical engineering.

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Plate-type metamaterials for extremely broadband low-frequency sound insulation

International Journal of Modern Physics B ◽

10.1142/s0217979218500194 ◽

2018 ◽

Vol 32 (03) ◽

pp. 1850019 ◽

Cited By ~ 3

Author(s):

Xiaopeng Wang ◽

Xinwei Guo ◽

Tianning Chen ◽

Ge Yao

Keyword(s):

Transmission Loss ◽

Structural Parameters ◽

Low Frequency ◽

Thin Plates ◽

Sound Insulation ◽

Frequency Noise ◽

Low Frequencies ◽

Acoustic Metamaterial ◽

Unit Cells ◽

Plate Type

A novel plate-type acoustic metamaterial with a high sound transmission loss (STL) in the low-frequency range ([Formula: see text]1000 Hz) is designed, theoretically proven and then experimentally verified. The thin plates with large modulus used in this paper mean that we do not need to apply tension to the plates, which is more applicable to practical engineering, the achievement of noise reduction is better and the installation of plates is more user-friendly than that of the membranes. The effects of different structural parameters of the plates on the sound-proofed performance at low-frequencies were also investigated by experiment and finite element method (FEM). The results showed that the STL can be modulated effectively and predictably using vibration theory by changing the structural parameters, such as the radius and thickness of the plate. Furthermore, using unit cells of different geometric sizes which are responsible for different frequency regions, the stacked panels with thickness [Formula: see text]16 mm and weight [Formula: see text]5 kg/m2 showed high STL below 2000 Hz. The acoustic metamaterial proposed in this study could provide a potential application in the low-frequency noise insulation.

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SeMSA: a compact super absorber optimised for broadband, low-frequency noise attenuation

Scientific Reports ◽

10.1038/s41598-020-73933-0 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Andrew McKay ◽

Ian Davis ◽

Jack Killeen ◽

Gareth J. Bennett

Keyword(s):

New Technology ◽

Perforated Plate ◽

Low Frequency ◽

Broadband Noise ◽

Frequency Noise ◽

Noise Attenuation ◽

Loss Mechanism ◽

Small Form Factor ◽

Broadband Sound ◽

Sub Wavelength

Abstract The attenuation of low-frequency broadband noise in a light, small form-factor is an intractable challenge. In this paper, a new technology is presented which employs the highly efficient visco-thermal loss mechanism of a micro-perforated plate (MPP) and successfully lowers its frequency response by combining it with decorated membrane resonators (DMR). Absorption comes from the membranes but primarily from the MPP, as the motion of the two membranes causes a pressure differential across the MPP creating airflow through the perforations. This combination of DMR and MPP has led to the Segmented Membrane Sound Absorber (SeMSA) design, which is extremely effective at low-frequency broadband sound absorption and which can achieve this at deep sub-wavelength thicknesses. The technology is compared to other absorbers to be found in the literature and the SeMSA outperforms them all in either the 20–1000 Hz or 20–1200 Hz range for depths of up to 120 mm. This was verified through analytical, finite element and experimental analyses.

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Fractal Acoustic Metamaterials with Subwavelength and Broadband Sound Insulation

Shock and Vibration ◽

10.1155/2019/1894073 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7

Author(s):

Yu Liu ◽

Meng Chen ◽

Wenshuai Xu ◽

Tao Yang ◽

Dongliang Pei ◽

...

Keyword(s):

Low Frequency ◽

Sound Insulation ◽

Acoustic Metamaterials ◽

The Finite Element Method ◽

Transmission Losses ◽

Effective Parameters ◽

Retrieval Method ◽

Sound Control ◽

S Parameter ◽

Broadband Sound

We construct new fractal acoustic metamaterials by coiling up space, which can allow subwavelength-scale and broadband sound insulation to be achieved. Using the finite element method and the S-parameter retrieval method, the band structures, the effective parameters, and the transmission losses of these acoustic metamaterials with different fractal orders are researched individually. The results illustrate that it is easy to form low-frequency bandgaps using these materials and thus achieve subwavelength-scale sound control. As the number of fractal orders increase, more bandgaps appear. In particular, in the ΓX direction of the acoustic metamaterial lattice, more of these wide bandgaps appear in different frequency ranges, thus providing broadband sound insulation and showing promise for use in engineering applications.

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Plate-Type Acoustic Metamaterials: Experimental Evaluation of a Modular Large-Scale Design for Low-Frequency Noise Control

Acoustics ◽

10.3390/acoustics1020019 ◽

2019 ◽

Vol 1 (2) ◽

pp. 354-368 ◽

Cited By ~ 2

Author(s):

Linus Ang ◽

Yong Koh ◽

Heow Lee

Keyword(s):

Large Scale ◽

Noise Control ◽

Traffic Noise ◽

Low Frequency ◽

Industrial Applications ◽

Frequency Noise ◽

Acoustic Metamaterials ◽

Scale Design ◽

Stress Uniformity ◽

Plate Type

For industrial applications, the scalability of a finalised design is an important factor to consider. The scaling process of typical membrane-type acoustic metamaterials may pose manufacturing challenges such as stress uniformity of the membrane and spatial consistency of the platelet. These challenges could be addressed by plate-type acoustic metamaterials with an internal tonraum resonator. By adopting the concept of modularity in a large-scale design (or meta-panel), the acoustical performance of different specimen configurations could be scaled and modularly combined. This study justifies the viability of two meta-panel configurations for low-frequency (80–500 Hz) noise control. The meta-panels were shown to be superior to two commercially available noise barriers at 80–500 Hz. This superiority was substantiated when the sound transmission class (STC) and the outdoor-indoor transmission class (OITC) were compared. The meta-panels were also shown to provide an average noise reduction of 22.7–27.4 dB at 80–400 Hz when evaluated in different noise environments—traffic noise, aircraft flyby noise, and construction noise. Consequently, the meta-panel may be further developed and optimised to obtain a design that is lightweight and yet has good acoustical performance at below 500 Hz, which is the frequency content of most problematic noises.

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Research on the Sound Insulation Properties of Membrane-type Acoustic Metamaterials

E3S Web of Conferences ◽

10.1051/e3sconf/202125202028 ◽

2021 ◽

Vol 252 ◽

pp. 02028

Author(s):

Jinyu Hao ◽

Sheng Guo ◽

Jian Cheng ◽

Zhaopin Hu ◽

Hongyu Cui

Keyword(s):

Cell Structure ◽

Sound Insulation ◽

Frequency Noise ◽

Acoustic Metamaterials ◽

Medium Frequency ◽

Low Frequencies ◽

Acoustic Metamaterial ◽

Membrane Type ◽

Insulation Performance ◽

Excessive Noise

Low- and medium-frequency noise from ship cabins is difficult to control effectively. Excessive noise can seriously affect the acoustic stealth performance of ships. A novel membrane-type acoustic metamaterial is proposed in this paper with light weight and good sound insulation performance at low frequencies. The sound insulation performance of the metamaterial structure is analysed by using the acoustic-solid coupling module in COMSOL software. Then, the ability to change the sound insulation performance of membrane-type acoustic metamaterials with cell structure and material parameters is obtained. The research results in this paper provide powerful technical support for noise control in ship cabins.

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Labyrinthine Structure with Subwavelength and Broadband Sound Insulation

Shock and Vibration ◽

10.1155/2020/8868324 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8

Author(s):

Heng Jiang ◽

Yu Liu ◽

Wenshuai Xu ◽

Tao Yang ◽

Dongliang Pei ◽

...

Keyword(s):

Structural Parameters ◽

Low Frequency ◽

Good Control ◽

Acoustic Properties ◽

Sound Insulation ◽

Sound Waves ◽

Effective Parameters ◽

Retrieval Method ◽

S Parameter ◽

Broadband Sound

In this text, the combination of spiral structure and zigzag channels is introduced to design labyrinthine structures, in which sound waves can propagate alternately in the clockwise and counterclockwise directions. Finite element method and S-parameter retrieval method are used to calculate band structures, effective parameters, and transmission properties of the structures. The influences of different structural parameters on their acoustic properties are also studied. These results show labyrinthine structures have multiple bandgaps in the range of 0 Hz–1000 Hz, and the proportion of bandgaps exceeds 33%, which indicates labyrinthine structures have good broadband properties. The normalized frequency of the lowest bandgaps is far smaller than 1, which indicates the structures take good control of sound waves on subwavelength scale. Combining units with different structural parameters can achieve better sound insulation. This research provides a new kind of space-coiling structure for low-frequency and broadband sound waves control, which have excellent application prospects.

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Research on Low Frequency Sound Insulation Properties of Membrane-Type Acoustic Metamaterials

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1210/1/012001 ◽

2021 ◽

Vol 1210 (1) ◽

pp. 012001

Author(s):

Xiaokai Yin ◽

Yongchao Xu ◽

Hongyu Cui

Keyword(s):

Noise Control ◽

Low Frequency ◽

Sound Insulation ◽

Frequency Noise ◽

Acoustic Metamaterials ◽

Frequency Sound ◽

Field Coupling ◽

Cabin Noise ◽

Sound Structure ◽

Membrane Type

Abstract To solve the problem of low-frequency noise control in ship cabins, a new membrane-type acoustic metamaterial (MAM) with bulges on the surface of thin films is designed based on the characteristics of lightweight and low-frequency sound insulation of membrane-type acoustic metamaterials. The sound structure coupling module of COMSOL multiphysical field coupling software is used to analyse the sound insulation performance of MAMs. The sound insulation properties of the additional mass film and self-similar fractal convex structure are further discussed. The metamaterial structure studied in this paper has a better sound insulation effect than ordinary film, which provides strong technical support for ship cabin noise control.

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The experimental study on low frequency sound transmission characteristics of the acoustic black hole

Modern Physics Letters B ◽

10.1142/s021798491950458x ◽

2019 ◽

Vol 33 (36) ◽

pp. 1950458 ◽

Cited By ~ 1

Author(s):

Xiao Liang ◽

Zhuo Zhou ◽

Jiu Hui Wu

Keyword(s):

Black Hole ◽

Low Frequency ◽

Sound Transmission ◽

Numerical Results ◽

Acoustic Energy ◽

Sound Insulation ◽

Frequency Noise ◽

Transmission Characteristics ◽

Acoustic Black Holes ◽

Insulation Performance

The acoustic black hole has good sound insulation performance in low frequency range. The transmission and insulation characteristics of acoustic black hole is investigated by experiments. First, we study the transmission and insulation characteristics of the acoustic black hole by numerical simulation. Second, we studied the sound transmission characteristic of multi-level acoustic black hole. Finally, the sound transmission and insulation characteristics of the acoustic black hole are studied by experiments. The influence of the acoustic black hole tip’s diameter on sound insulation coefficient is studied. The sound transmission characteristics of the first, two and three level acoustic black holes are also studied by experiments. Our numerical results show that low frequency acoustic energy can be effectively focused at the tip of the acoustic black hole, and can be effectively insulated by the acoustic black hole. Our numerical results are verified by the experimental results. Our study can provide a feasible method for controlling the low frequency noise.

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