Strong-reflection underwater acoustic material and application thereof

An underwater acoustic material, strong reflection technology, applied in the directions of sound-producing equipment, measuring ultrasonic/sonic/infrasonic waves, measuring devices, etc., to achieve the effect of good application prospects

Active Publication Date: 2018-11-16
BEIJING INSTITUTE OF TECHNOLOGYGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Aiming at the current lack of strong reflection materials for underwater sound, the present invention provides a strong reflection underwater acoustic material, which has low impedance and high stiffness characteristics, and is effective for broadb

Method used

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  • Strong-reflection underwater acoustic material and application thereof
  • Strong-reflection underwater acoustic material and application thereof
  • Strong-reflection underwater acoustic material and application thereof

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Effect test

Embodiment 1

[0037] The simulated frequency range of the strong reflection plate prepared by using the steel plate and the strong reflection underwater acoustic material of the present invention is 0-700Hz, the thickness of the steel plate and the strong reflection plate are both 21mm, and the wavelength in water is at least 119 times the thickness of the plate. The density and bulk modulus of water is ρ 0 =1000kg / m 3 and K 0 =2.25GPa, the density, Young's modulus and Poisson's ratio of the steel plate are ρ steel =7800kg / m 3 ,E steel = 220GPa and v steel=0.28, the density, stiffness and five-mode characteristic parameters of the strong reflector are ρ s =0.5ρ 0 、K x =0.1K 0 、K y =10K 0 , π=0.999, μ=0.001. The included angle between the main axis and the interface of the strongly reflective underwater acoustic material described in this embodiment is θ=15°, and the wave velocity ratio of the excited shear wave to the longitudinal wave is c T / c L ≈0.015, the longitudinal wave ...

Embodiment 2

[0041] The strong reflective underwater acoustic material described in this embodiment is a honeycomb five-mode material composed of hexagonal unit cells, and the unit cells are composed of Y-shaped rods and cavities 1-3, such as image 3 Shown; fill air or vacuum in the cavity 1-3, Y-shaped bar is formed by the intersecting of a vertical bar 1-1 and two oblique bars 1-2 left and right symmetrically distributed in the unit cell, vertical bar 1- 1 and the disjoint other ends of the two oblique rods 1-2 are respectively located at three non-adjacent vertices in the hexagon; wherein, l is the length of the oblique rod 1-2, m is the length of the vertical rod 1-1, t is the thickness of the vertical bar 1-1 and the inclined bar 1-2, and β is the angle between the extension line of the vertical bar 1-1 and the inclined bar 1-2;

[0042] The specific parameters of the strong reflective underwater acoustic material described in this embodiment are: t=0.4mm, β=74.2°, m=2mm, l=8mm; the ...

Embodiment 3

[0047] The low-frequency and high-directional sound source is a necessary equipment for large-scale acoustic model verification. The high-directional sound waves directly incident on the test target 3 can avoid interference to the experiment through water surface and underwater transmission. The existing low-frequency high-directional sound source is mainly realized by a transducer array, and multiple transducers 2 sound simultaneously to generate an approximate plane wave, which has disadvantages such as a large number of transducers 2, huge cost, and insufficient directivity.

[0048] Based on the strongly reflective underwater acoustic material described in the present invention, this embodiment proposes a low-frequency high-directional sound source assembly, the assembly includes a transducer 2 and an arc reflector 1, and the arc reflector 1 adopts Made of the underwater acoustic material of the present invention;

[0049] The transducer 2 is placed at the focal point of t...

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Abstract

The invention relates to a strong-reflection underwater acoustic material and an application thereof, and belongs to the technical fields of underwater acoustic material design and underwater acousticpropagation control. The underwater acoustic material needs to meet the following conditions: the ratio of shear wave velocity to longitudinal wave velocity is less than 1/5, the ratio of the stiffness in the y principal axis direction and the stiffness in the x principal axis direction is greater than 10, and an angle [Theta] between a principal axis and an interface is not equal to 0 degree and90 degrees. The underwater acoustic material has the characteristics of low impedance and high stiffness, is effective for broadband and oblique incident acoustic waves at the same time and can meetunderwater acoustic strong reflection requirements in a deep high-pressure environment. In addition, the underwater acoustic material has excellent application prospects on the aspects of underwater noise prevention, low-frequency underwater acoustic high-directivity sound sources and acoustic pressure detection.

Description

technical field [0001] The invention relates to an underwater acoustic material with strong reflection characteristics and its application, and belongs to the technical field of underwater acoustic material design and underwater acoustic propagation control. Background technique [0002] When a sound wave is incident from one medium to another, energy reflection occurs due to impedance mismatch. This physical phenomenon is called wave reflection. Acoustic reflection has important applications in both life and scientific research: the sound insulation board on the side of the highway can block the noise by reflecting the noise; by using the strong reflection of the solid to the air sound, a two-dimensional planar air acoustic waveguide can be designed by using a solid thin plate. In the above-mentioned sound insulation and waveguide applications, the reflection strength of the material to sound waves is the key factor affecting the design. The stronger the reflection of the m...

Claims

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Application Information

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IPC IPC(8): G01H17/00G10K11/162
CPCG01H17/00G10K11/162
Inventor 胡更开陈毅刘晓宁
Owner BEIJING INSTITUTE OF TECHNOLOGYGY
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