Underwater sound absorption metamaterial based on novel pore cavity

A technology of metamaterials and cavities, applied in the direction of sound-generating devices, instruments, synthetic resin layered products, etc., can solve the problems of acoustic performance degradation, easy deformation, etc., to enhance water pressure resistance, meet integration requirements, and designability strong effect

Active Publication Date: 2020-11-06
NAT INNOVATION INST OF DEFENSE TECH PLA ACAD OF MILITARY SCI
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The purpose of the present invention is to solve the technical problem that the traditional cavity-containing polymer is easily deformed under high hydrostatic pressure, which leads t

Method used

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  • Underwater sound absorption metamaterial based on novel pore cavity
  • Underwater sound absorption metamaterial based on novel pore cavity
  • Underwater sound absorption metamaterial based on novel pore cavity

Examples

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Embodiment 1

[0044] The cell side length is 50mm and the thickness is 70mm. The thickness of each layer of fiber reinforced resin panels is 2mm. The fiber reinforced resin panels are glass fiber reinforced resin materials with an elastic modulus of 18GPa, a Poisson's ratio of 0.15, and a density of 1700g / cm. 3 . The thickness of the upper and lower layers of viscoelastic polymer is 26mm and 38mm respectively, and the viscoelastic polymer is modified polyurethane with a density of 960kg / m 3 , the Young's modulus is 30MPa, the Poisson's ratio is 0.49, and the equivalent isotropic loss factor is 0.5. In the combined cavity, the bottom cavity of the upper cavity has a radius of 6mm and a height of 22mm, and the cavity radius varies between 2 and 6mm with the height; the lower cavity has a radius of 20mm and a height of 32mm, and the cavity radius changes with the height. Change between 8 and 20mm. The characteristic density of water is 1000kg / m 3 , the speed of sound is 1500m / s. The prepar...

Embodiment 2

[0047] The side length of the cell is 48mm and the thickness is 68mm. The thickness of each layer of fiber reinforced resin panels is 2mm. The fiber reinforced resin panels are carbon fiber reinforced resin materials with an elastic modulus of 80GPa, a Poisson's ratio of 0.15, and a density of 1200g / cm. 3 . The thickness of the upper and lower layers of viscoelastic polymer is 24mm and 38mm respectively, the viscoelastic polymer adopts modified polyurethane, and the density is 1100kg / m 3 , the Young's modulus is 35MPa, the Poisson's ratio is 0.49, and the equivalent isotropic loss factor is 0.45. In the combined cavity, the bottom cavity of the upper cavity has a radius of 7 mm and a height of 20 mm, and the cavity radius varies from 1 to 7 mm with the height; the lower cavity has a radius of 22 mm and a height of 30 mm. Change between 7 ~ 22mm. The characteristic density of water is 1000kg / m 3 , the speed of sound is 1500m / s. In the preparation process of underwater sound...

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Abstract

The invention provides an underwater sound absorption metamaterial based on an optimized pore cavity. The underwater sound absorption metamaterial comprises periodically arranged cellular units, and each cell is composed of three parts: a fiber reinforced resin panel, a viscoelastic polymer layer and an optimized pore cavity combination. The three fiber reinforced resin panels divide the cell intoan upper layer and a lower layer with different heights along the incident propagation direction of the sound part, the two layers are filled with viscoelastic polymers, and the optimized pore cavitycombination comprises two independent pore cavities which are respectively positioned in the two layers of viscoelastic polymers. The pore cavity of the underwater sound absorption metamaterial adopts a curve optimization type appearance to realize low-frequency broadband sound absorption, and the fiber reinforced resin panel is adopted to enhance the water pressure resistance so that the fiber reinforced resin panel can be applied to the condition that the two ends are both water backs, the limitation that the traditional polymer containing the pore cavity needs to be attached to a rigid shell material is overcome, and a new choice is provided for an underwater sound absorption material. The metamaterial has the characteristics of simple structure, readily available raw materials, maturepreparation process, strong designability of geometric parameters of the pore cavity and the like, meets the integrated requirements of light weight and low-frequency broadband sound absorption, andhas wide application in the fields of sound absorption skins of underwater equipment or vibration and noise reduction materials and the like.

Description

technical field [0001] The invention belongs to the technical field of underwater sound absorption, in particular to an underwater sound absorption metamaterial based on a novel cavity. Background technique [0002] Underwater acoustic detection and stealth have always been important technical problems in the field of underwater acoustic engineering. With the continuous development of underwater acoustic detection technology and equipment, its active and passive detection frequencies continue to develop to low frequencies, thus enabling long-distance detection threats. Damping polymer materials embedded with periodically distributed cavities have been widely studied and applied in the field of underwater sound absorbing materials, including resonant and non-resonant types. They are usually laid on the steel shell of underwater equipment to absorb underwater sound waves. . [0003] The resonant sound-absorbing structure is usually divided into several layers, and the pore s...

Claims

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Application Information

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IPC IPC(8): B32B3/26B32B27/08B32B27/40B32B27/04B32B33/00G10K11/168B29C39/02
CPCB32B3/26B32B27/08B32B27/40B32B33/00G10K11/168B29C39/02B32B2260/021B32B2260/046B32B2307/102
Inventor 邹春荣周晓松沈同圣郭少军黎松
Owner NAT INNOVATION INST OF DEFENSE TECH PLA ACAD OF MILITARY SCI
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