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Low-frequency sound absorption covering layer with gradient change cylindrical cavity

A technology of sound-absorbing covering layer and gradient change, which is applied in the direction of sound-emitting devices and instruments, can solve the problem of narrow frequency bandwidth and achieve simple structure, good underwater low-frequency sound absorption effect, and simple structure

Active Publication Date: 2021-03-26
HARBIN ENG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The structure is a sound-absorbing structure in which a single-layer cylindrical cavity array is distributed in PDMS silicone rubber. The axis of the cylindrical cavity is perpendicular to the direction of the incident sound wave. The cavity resonance and waveform conversion mechanism can greatly attenuate the incident sound wave, and The effective sound absorption frequency can reach the low frequency range of hundreds of hertz, but the frequency bandwidth is narrow

Method used

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  • Low-frequency sound absorption covering layer with gradient change cylindrical cavity
  • Low-frequency sound absorption covering layer with gradient change cylindrical cavity
  • Low-frequency sound absorption covering layer with gradient change cylindrical cavity

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] 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 cavities are distributed in the sound-absorbing covering. The sound-absorbing covering layer with the same number and spacing of the cylindrical cavities of the present invention is compared with the sound-absorbing covering layer with the same number and spacing of the cylindrical cavities. For the embodiment of the present invention, the sound-absorbing covering layer with gradient changes in the number and spacing of cylindrical cavities: in each unit, the first layer contains 1 cylindrical cavity, and the second layer contains 2 cylindrical cavities at equ...

Embodiment 2

[0028] 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 cavities are distributed in the sound-absorbing covering.

[0029] The sound-absorbing covering layer with the number and gradient of the cylindrical cavities with different parameters from that of Example 1 was used for comparison with the sound-absorbing covering layer with the same number and spacing of cylindrical cavities. In the embodiment of the present invention, the sound-absorbing covering layer with a gradient change in the number and spacing of cylindrical cavities: in each unit, the first layer contains 1 cylindrical cavity, and the second layer c...

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Abstract

The invention discloses a low-frequency sound absorption covering layer with a gradient change cylindrical cavity, and relates to the technical field of underwater navigation detection. 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, and the section of the front surface of the sound absorption layer is rectangular; in each unit, a first-layer cylindrical cavity, a second-layer cylindrical cavity and a third-layer cylindrical cavity are distributed in the incident direction, one cylindrical cavity is distributed in the first layer, two cylindrical cavities are distributed in the second layer at equal intervals,and three cylindrical cavities are distributed in the third layer at equal intervals; sealing layers are arranged at the two ends of the first-layer cylindrical cavity, the two ends of the second-layer cylindrical cavity and the two ends of the third-layer cylindrical cavity; the sealing layer and the sound absorption layer are both made of PDMS, and the base layer is made of a steel material. Thecovering layer is advantaged in that the number of the cylindrical cavities is designed in a gradient change mode, the frequency range of a sound absorption frequency band can be effectively reduced,good low-frequency sound absorption performance is obtained through a simple structure, the structure is simple, and the low-frequency sound absorption device is suitable for being applied to low-frequency vibration and noise reduction.

Description

technical field [0001] The invention relates to the technical field of underwater navigation detection, in particular to a low-frequency sound-absorbing covering layer containing a gradient-varying cylindrical cavity. Background technique [0002] The sound-absorbing coating is widely used to cover the shell of the underwater vehicle, which can suppress the vibration of the shell and absorb the detection sound waves of the active sonar, reduce the acoustic reflection intensity of the underwater vehicle, and then reduce the intensity of the active sonar Detection distance. At present, most of the sound-absorbing covering layers used at home and abroad are made of rubber materials with certain damping properties. The rubber layer is embedded with periodic cavity structures, such as spherical, frustum-shaped, cylindrical, etc., using cavity resonance and waveform conversion The mechanism of relaxation effect can effectively absorb sound waves. However, the sound-absorbing fre...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G10K11/168
CPCG10K11/168
Inventor 胡博王世博杜逸眉李明杰陈聪
Owner HARBIN ENG UNIV
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