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Low-frequency sound absorption metamaterial

A metamaterial and sound absorption technology, applied in the field of sound absorption metamaterials, can solve the problems of large structure thickness, poor sound absorption effect, narrow sound absorption frequency, etc., and achieve the effect of small structure thickness, convenient adjustment and improvement of absorption efficiency.

Active Publication Date: 2019-09-24
BEIJING INSTITUTE OF TECHNOLOGYGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problems of existing sound-absorbing materials such as large structural thickness, narrow sound-absorbing frequency, and poor sound-absorbing effect on sound waves below 300 Hz, the purpose of the present invention is to provide a low-frequency sound-absorbing metamaterial, mainly based on a piezoelectric material circuit Control theory, through the external circuit to control the piezoelectric film and piezoelectric stack separately, can greatly improve the matching of acoustic resistance and acoustic reactance, improve the sound absorption performance of metamaterials, and do not need to change its geometric configuration and size, It has a good absorption effect for sound waves below 300Hz

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0121] Such as figure 1 As shown, a wide and low-frequency sound-absorbing metamaterial includes a back cavity 1, a composite film, a piezoelectric film circuit, a piezoelectric stack, and a piezoelectric stack circuit;

[0122] The back cavity 1 is a cavity structure with one end open, and its thickness h c 3cm;

[0123] The composite film is a composite structure formed by bonding the piezoelectric film 2, the metal film 3 and the piezoelectric film 2 in order; wherein the piezoelectric film 2 is a ring structure, and the center of the metal film 3 is processed with a convex platform structure, the piezoelectric film 2 is nested on the boss structure of the metal film 3; the material of the piezoelectric film 2 is a PZT-5H piezoelectric ceramic material, and the other metal film 3 is an aluminum film; in addition, figure 2 R in 1 =1mm, R 2 =20mm, R 3 = 40mm and R 4 = 60mm, the thickness of the piezoelectric film 2 inside and outside the cavity of the back cavity 1 is ...

Embodiment 2

[0130] On the basis of Example 1, modify the negative capacitance I4 to -350nF, the resistance 5 to 180Ω, the negative capacitance II7 to -1.4503nF, and the negative inductance 8 to -1.4H. Other structural components and parameter settings of the material are the same as those of the wide and low frequency sound-absorbing metamaterial in Example 1.

[0131] Apply a normal incident sound wave within 300 Hz to the wide and low frequency sound-absorbing metamaterial described in this example, and evaluate the sound-absorbing effect through theoretical calculation and simulation in the finite element software Comsol. The theoretical calculation and simulation results are detailed in Figure 4 . Through theoretical calculation, it can be seen that the sound-absorbing metamaterial can achieve an absorption rate of more than 0.9 in the range of 91Hz-250Hz, such as Figure 4 As shown in the middle curve A; through the simulation, it can be known that the sound-absorbing metamaterial ...

Embodiment 3

[0133] On the basis of Example 1, modify the negative capacitance I4 to -400nF, the resistance 5 to 55Ω, the negative capacitance II7 to -1.4496nF, and the negative inductance to 0H. In this embodiment, the adjustable narrow low-frequency sound-absorbing metamaterial Other structural components and parameter settings are the same as those of the wide and low frequency sound-absorbing metamaterial in Example 1.

[0134] Apply normal incident sound waves within 300 Hz to the adjustable narrow low-frequency sound-absorbing metamaterial described in this example, and evaluate the sound-absorbing effect through theoretical calculation and simulation in the finite element software Comsol, the results of theoretical calculation and simulation simulation See details Figure 5 . According to theoretical calculations, the absorption rate of the sound-absorbing metamaterial is 0.88 at 81 Hz, as Figure 5 As shown in the middle curve I-A; through simulation, it can be seen that the abso...

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Abstract

The invention relates to a low-frequency sound absorption metamaterial, and belongs to the technical field of sound absorption metamaterials. The sound absorption metamaterial disclosed by the invention is mainly based on a circuit control theory of a piezoelectric material, a piezoelectric film and a piezoelectric stack are independently regulated and controlled through a piezoelectric film circuit and a piezoelectric stack circuit, and the matching condition of the acoustic resistance and the acoustic reactance can be greatly improved without changes of the geometric configuration and the size. The sound absorption strength, the sound absorption frequency and the sound absorption bandwidth of the sound absorption metamaterial are regulated and controlled, a wide sound absorption frequency range is achieved for sound waves below 300 Hz, and the sound absorption frequency can be regulated within the wide range. The sound absorption metamaterial is small in structural thickness, small in size and high in sound absorption efficiency, and the limitation of a traditional method and a common metamaterial in low-frequency (smaller than or equal to 300 Hz) sound absorption is broken through.

Description

technical field [0001] The invention specifically relates to an ultra-thin and light-weight metamaterial with good sound-absorbing effect on sound waves within 300 Hz, and belongs to the technical field of sound-absorbing metamaterials. Background technique [0002] Noise pollution exists widely in our lives, such as urban construction, transportation, industrial production, aerospace and other fields, causing great harm to people's physical and mental health, especially low-frequency noise is a difficult point to deal with. Traditional sound absorption methods mainly include porous media (such as sponges, foams, fiber felts, etc.) and perforated and micro-perforated plates, which absorb sound based on damping dissipation and heat conduction mechanisms, and have good sound absorption effects for mid- and high-frequency noise, but The loss of low-frequency sound waves is very weak, and a structure or material equivalent to the size of the wavelength is required to have a cert...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G10K11/168B32B9/00B32B9/04B32B3/30B32B3/24
CPCB32B3/266B32B3/30B32B9/005B32B9/041B32B2307/10G10K11/168
Inventor 周萧明廖允鸿
Owner BEIJING INSTITUTE OF TECHNOLOGYGY
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