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Low-frequency sound absorption covering layer containing cylindrical scatterers with parameters changing in gradient mode

A technology of sound-absorbing covering layer and gradient change, which is applied in the direction of sound-emitting devices, layered products, and metal-layered products. simple effect

Pending Publication Date: 2021-12-17
HARBIN ENG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The optimization results show that there is a broadband sound absorption effect in the 1.3kHz-10kHz frequency band, and it is verified that the sound absorption performance of the broadband can be effectively improved by laying a sound-absorbing layer with different parameters, but the sound absorption coefficient in the 1000-2000Hz frequency band lower

Method used

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  • Low-frequency sound absorption covering layer containing cylindrical scatterers with parameters changing in gradient mode
  • Low-frequency sound absorption covering layer containing cylindrical scatterers with parameters changing in gradient mode
  • Low-frequency sound absorption covering layer containing cylindrical scatterers with parameters changing in gradient mode

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Embodiment 1

[0029] The material of the sound-absorbing layer and the sealing layer in the sound-absorbing cover layer of the present invention is a kind of PDMS silicone rubber, and the density of the PDMS silicone rubber is 1000kg / m 3 , the complex Young's modulus is (1.879+0.540i) MPa, and Poisson's ratio is 0.4997. The density of the base layer is 7890kg / m 3 , Young's modulus is 210GPa, Poisson's ratio is 0.3. Three layers of cylindrical cavities are distributed in the sound-absorbing covering.

[0030] In the present invention, the low-frequency sound-absorbing covering layer containing a cylindrical scatterer with a parameter changing in gradient, the sound-absorbing covering layer containing a cylindrical cavity with a parameter changing in a gradient, and the low-frequency sound-absorbing covering layer containing a cylindrical scatterer with a parameter changing in a negative gradient comparing. For the sound-absorbing covering layer of the present invention containing cylindri...

Embodiment 2

[0033] The material of the sound-absorbing layer and the sealing layer in the sound-absorbing covering layer of this example is a kind of PDMS silicone rubber, and the density of PDMS silicone rubber is 1000kg / m 3 , the complex Young's modulus is (1.879+0.540i) MPa, and Poisson's ratio is 0.4997. The density of the base layer is 7890kg / m 3 , Young's modulus is 210GPa, Poisson's ratio is 0.3. Three layers of cylindrical diffusers are distributed in the sound-absorbing covering.

[0034] Compared with the present invention, the sound-absorbing covering layer with the thickness of the cladding layer in two cylindrical scatterers having a different distribution from the sound-absorbing covering layer containing the cylindrical scatterer whose parameters change in gradients in the present invention is used for comparison. For the sound-absorbing coating of the present invention that contains cylindrical scatterers whose parameters vary in gradient: in each unit, the first layer, ...

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Abstract

The invention relates to a low-frequency sound absorption covering layer containing cylindrical scatterers with parameters changing in a gradient mode. The low-frequency sound absorption covering layer comprises a sealing layer, a sound absorption layer and a base layer, wherein the sound absorption layer is formed by periodically arranging a plurality of identical cuboid units, a sealing layer is attached to the front surface of the sound absorption layer to guarantee water tightness, and the base layer is attached to the lower surface of the sound absorption layer to simulate a shell of an underwater structure. Three cylindrical scatterers are arranged in each unit of the sound absorption layer from top to bottom. Each cylindrical scatterer is formed by wrapping the side face of a cylindrical cavity with two layers of elastic rubber having the same thickness and different moduli. The sealing layer and the sound absorption layer are made of polydimethylsiloxane (PDMS) silicone rubber, and the base layer is made of a steel material. The problem that the low-frequency sound absorption performance is poor due to the fact that a single material is adopted is solved, the moduli and the thicknesses of coating layers in the cylindrical scatterers are designed to be in gradient change, so the frequency range of a sound absorption frequency band can be effectively reduced, and a sound absorption coefficient is improved. The covering layer is high in designability and suitable for being applied to the aspects of low-frequency vibration reduction and noise reduction.

Description

technical field [0001] The invention relates to a low-frequency sound-absorbing covering layer containing a cylindrical scatterer with gradient parameters, in particular to a low-frequency sound-absorbing covering layer in which the cylindrical scatterer is a cavity covered with multiple layers of elastic materials. Background technique [0002] The sound-absorbing coating is widely used to cover the shell of underwater vehicles, and its acoustic performance is an important indicator for judging the acoustic stealth ability of underwater vehicles. The function of the sound-absorbing coating is mainly reflected in two aspects: one is to reduce the probability of being discovered by the enemy's passive sonar and its range of action by reducing the radiation noise level of the aircraft; the other is to reduce the acoustic target of the aircraft. Intensity, thereby increasing the detection range of the enemy's active sonar. At present, most of the sound-absorbing covering layer...

Claims

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Application Information

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IPC IPC(8): G10K11/168G10K11/16B63G8/34B63C11/52B32B25/20B32B15/18B32B15/06B32B7/12B32B3/26B32B3/08
CPCG10K11/168G10K11/161B32B15/18B32B25/20B32B15/06B32B3/085B32B7/12B32B3/26B63G8/34B63C11/52B32B2307/10B32B2307/56
Inventor 胡博王世博李松张揽月杜逸眉刘凯王帅印
Owner HARBIN ENG UNIV
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