Sound attenuating structures

Patent metadata

Field	Value
Publication number	US-9466283-B2
Application number	US-201414772968-A
Country	US
Kind code	B2
Filing date	Mar 12, 2014
Priority date	Mar 12, 2013
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

A sound attenuation panel is configured with a substantially acoustically transparent planar, rigid frame divided into a plurality of individual, substantially two-dimensional cells. A sheet of a flexible material is fixed to the rigid frame, and a plurality of platelets fixed to the sheet of flexible material such that each individual cell of the plurality of cells is provided with a respective platelet to establish a resonant frequency, the resonant frequency defined by the planar geometry of the individual cells, the flexibility of the flexible material and the platelets. The cells are divided into at least two different types of the individual cells, configured so that sound waves emitted by a first type of said different types of individual cells establishes a sound cancellation pattern with sound waves emitted by a second type of said different individual cells or an aggregation of different types of the individual cells.

First claim

What is claimed is:

1. A sound attenuation panel comprising:
a substantially acoustically transparent planar, rigid frame divided into a plurality of individual, substantially two-dimensional cells;
a sheet of a flexible material fixed to the rigid frame, and a plurality of platelets fixed to the sheet of flexible material such that each individual cell of the plurality of cells is provided with a respective platelet, thereby establishing a resonant frequency, the resonant frequency defined by the planar geometry of the respective individual cells, the flexibility of the flexible material and said respective platelet thereon, and the resonant frequency tuned by adjusting at least one of a mass on the sheet of flexible material, said mass comprising one of said platelets, dimensions of the flexible material and tension on the flexible material; and
the plurality of cells divided into at least two different types of the individual cells, distributed in a planar arrangement in an alternating fashion or according to a predetermined pattern on the sound attenuation panel, the different types of individual cells configured so that sound waves emitted by a first type of said different types of individual cells establishes a sound cancellation pattern with sound waves emitted by a second type of said different individual cells or an aggregation of different types of the individual cells.

2. The sound attenuation panel of claim 1 , further comprising the different types of individual cells having a configuration comprising the planar geometry of the respective individual cells, the flexibility of the flexible material and said respective platelet thereon that establishes an out-of-phase relationship between sound waves emitted by at least two of the different types of individual cells.

3. The sound attenuation panel of claim 1 , wherein at least a plurality of the cells comprise sizable orifices or openings through which air can flow freely sufficiently for providing or promoting air ventilation.

4. The sound attenuation panel of claim 1 , further comprising each cell constructed into said least two different types of the individual cells as type-A cells and type-B cells arranged in a predetermined alternating pattern.

5. The sound attenuation panel of claim 4 , wherein:
the type-A cells each comprise a sheet of elastic material fixed on the cell frame, and at least one platelet attached to the sheet; and
the type-B cells each comprise a sheet of elastic material fixed on the cell frame, and either at least one platelet having a weight different from that of platelets attached to the type-A cells attached to the sheet, or without a platelet.

6. The sound attenuation panel of claim 4 , wherein said platelets have a mass in the range of 0.1 to 10 g.

7. The sound attenuation panel of claim 4 , wherein said sheet comprises multiple layers of said flexible material.

8. The sound attenuation panel of claim 4 , wherein:
the sheet of flexible materials comprise impermeable flexible material.

9. A sound attenuation panel comprising:
a plurality of panels stacked together, wherein each panel of the plurality of panels comprises a rigid frame divided into a plurality of individual cells;
a sheet of a flexible material;
a plurality of platelets affixed to the sheet of flexible material such that each of the plurality of individual cells has attached thereto at least one of said platelets, whereby said cells have resonant frequencies defined by the planar geometry of each said individual cell, the flexibility of said flexible material and said respective platelet thereon, and the resonant frequency tuned by adjusting at least one of a mass on the sheet of flexible material, said mass comprising one of said platelets, dimensions of the flexible material and tension on the flexible material; and
the plurality of cells divided into at least two different types of the individual cells, distributed in a planar arrangement in an alternating fashion or according to a predetermined pattern on the panel, the different types of individual cells configured so that sound waves emitted by a first type of said different types of individual cells establishes a sound cancellation pattern with sound waves emitted by a second type of said different individual cells or an aggregation of different types of the individual cells.

10. The sound attenuation panel of claim 9 , further comprising the different types of individual cells having a configuration comprising the planar geometry of the respective individual cells, the flexibility of the flexible material and said respective platelet thereon that establishes an out-of-phase relationship between sound waves emitted by at least two of the different types of individual cells.

11. A sound attenuation panel comprising:
a substantially acoustically transparent planar, rigid frame divided into a plurality of individual, substantially two-dimensional cells;
a sheet of a flexible solid material fixed to the rigid frame, and a plurality of platelets fixed to the sheet of flexible material such that each cell is provided with a respective platelet, thereby establishing a resonant frequency, the resonant frequency defined by the planar geometry of the respective individual cells, the modulus of elasticity of the solid material and said respective platelet thereon, and the resonant frequency tuned by adjusting at least one of a mass on the sheet of flexible material, said mass comprising one of said platelets, dimensions of the flexible material and tension on the flexible material; and
a membrane selected to provide a resonant characteristic for at least a subset of the cells, with selection criteria including at least one of thickness of the membrane, elasticity of the membrane, Young's modulus and the Poisson ratio of the membrane, the mass and dimension of the platelet, and the cell dimension, said resonant characteristic providing a selection of a working frequency in the range from subsonic (below 1 Hz) to ultrasonic (above 1 MHz).

12. The sound attenuation panel of claim 11 , further comprising:
the plurality of cells divided into at least two different types of the individual cells, distributed in a planar arrangement in an alternating fashion or according to a predetermined pattern on the panel, the different types of individual cells configured so that sound waves emitted by a first type of said different types of individual cells establishes a sound cancellation pattern with sound waves emitted by a second type of said different individual cells or an aggregation of different types of the individual cells.

13. The sound attenuation panel of claim 11 , wherein the thickness of the sheet of solid materials varies across the cell.

14. The sound attenuation panel of claim 11 , further comprising:
multiple layers of said solid material.

15. The sound attenuation panel of claim 11 , further comprising:
a plurality of panels stacked together wherein each said panel comprises a rigid frame divided into a plurality of individual cells, a sheet of a solid material, and a plurality of platelets, with each platelet fixed to said sheet of solid material to provide each cell with a respective platelet;
a working frequency of the sound attenuation structure defined by the planar geometry of the individual cells, the flexibility of said solid material, and said respective platelet thereon.

16. The sound attenuation panel of claim 15 , further comprising:
each said panel formed with platelets having different weights from other said panels in the panel.

17. A sound atten

Assignees

• Univ Hong Kong Science & Tech

Inventors

• Yang Zhiyu
• Sheng Ping
• Ma Guancong
• Yang Min
• Li Yong

Classifications

• G10K11/172

  using resonance effects · CPC title

• G10K11/175 Primary

  using interference effects; Masking sound · CPC title