Sound barrier systems

Patent metadata

Field	Value
Publication number	US-9163398-B2
Application number	US-201414281408-A
Country	US
Kind code	B2
Filing date	May 19, 2014
Priority date	May 17, 2013
Publication date	Oct 20, 2015
Grant date	Oct 20, 2015

Abstract

A cellular material barrier system for reducing sound transmission. The cellular material system includes a planar cellular metamaterial arrangement which includes at least one unit cell, the unit cell includes a sound normalizing arrangement, and a planar metamaterial arrangement coupled to the sound normalizing arrangement on a first side, the planar metamaterial arrangement includes a plate, and a frame affixed to the plate, the sound normalizing arrangement configured to normalize incident sound received at non-normal angle to thereby convey sound at normal angles to the planar metamaterial arrangement, the unit cell further comprising a back layer that is coupled to the sound normalizing arrangement on a second side, opposite the first side, the back layer is made from a porous material, including at least one of a fibrous layer, polymeric foams, ceramic foams, and metallic foams.

First claim

The invention claimed is:

1. A cellular material barrier system for reducing sound transmission comprising:
a planar cellular metamaterial arrangement, including at least one unit cell, the unit cell including
a sound normalizing arrangement; and
a planar metamaterial arrangement coupled to the sound normalizing arrangement on a first side, the planar metamaterial arrangement including
a plate, and
a frame affixed to the plate,

the sound normalizing arrangement configured to normalize incident sound received at non-normal angles to thereby convey sound at normal angles to the planar metamaterial arrangement.

2. The cellular material barrier system of claim 1 , the sound normalizing arrangement comprises a lattice structure having a plurality of sound normalizing cells, the plurality of sound normalizing cells configured to normalize incident sound for a frequency range.

3. The cellular material barrier system of claim 2 , the frequency range between 1 and 4,000 Hz.

4. The cellular material barrier system of claim 2 , the frequency range between 1 and 10,000 Hz.

5. The cellular material barrier system of claim 3 , each cell of the plurality of sound normalizing cells having a polygon shape with a depth of at least about 2 mm.

6. The cellular material barrier system of claim 2 , the sound normalizing arrangement made from a low sound speed porous material.

7. The cellular material barrier system of claim 2 , the sound normalizing arrangement made from wood.

8. The cellular material barrier system of claim 2 , the sound normalizing arrangement made from at least one of a composite, polymeric, and metallic materials.

9. The cellular material barrier system of claim 8 , a sub-plurality of the plurality of sound normalizing cells filled with porous sound absorbing material.

10. The cellular material barrier system of claim 1 , the unit cell further comprising a back layer coupled to the sound normalizing arrangement on a second side, opposite the first side, the back layer made from a porous material, including at least one of a fibrous layer, polymeric foams, ceramic foams, and metallic foams.

11. The cellular material barrier system of claim 10 , the porous material includes glass fibers with mass density of less than about 30 kg/m 3 .

12. The cellular material barrier system of claim 1 , wherein ratio of mass of the frame and mass of the plate is between about 1 to about 100.

13. The cellular material barrier system of claim 1 , wherein ratio of elastic modulus of the frame material to elastic modulus of the plate material is between about 1 to about 100.

14. A method for improving sound transmission loss (STL), comprising:
placing a sound normalization arrangement about a space where improving STL is desired, the sound normalization layer configured to normalize incident sound received at non-normal angles to thereby convey sound at normal angles; and
coupling a planar metamaterial arrangement to the sound normalizing arrangement on a first side, the planar metamaterial arrangement including
a plate, and
a frame affixed to the plate.

15. The method of claim 14 , the sound normalizing arrangement comprises a lattice structure having a plurality of sound normalizing cells, the plurality of sound normalizing cells configured to normalize incident sound for a frequency range.

16. The method of claim 15 , the frequency range between 1 and 4,000 Hz.

17. The method of claim 15 , the frequency range between 1 and 10,000 Hz.

18. The method of claim 16 , each cell of the plurality of sound normalizing cells having a polygon shape with a depth of at least about 2 mm.

19. The method of claim 14 , the sound normalizing arrangement made from a low sound speed porous material.

20. The method of claim 15 , the sound normalizing arrangement made from a composite material.

21. The method of claim 20 , a sub-plurality of the plurality of sound normalizing cells filled with porous sound absorbing material.

22. The method of claim 14 , further comprising coupling a back layer to the sound normalizing arrangement on a second side, opposite the first side, the back layer made from a porous material, including at least one of a fibrous layer, polymeric foams, ceramic foams, and metallic foams.

23. The method of claim 22 , the porous material includes glass fibers with mass density of less than about 30 kg/m 3 .

24. The method of claim 14 , wherein ratio of mass of the frame and mass of the plate is between about 1 to about 100.

25. The method of claim 14 , wherein ratio of elastic modulus of the frame material to elastic modulus of the plate material is between about 1 to about 100.

Assignees

• Purdue Research Foundation

Inventors

• Varanasi Satya Surya Srinivas
• Khandelwal Somesh
• Siegmund Thomas
• Bolton John Stuart
• Cipra Raymond J

Classifications

• E04B1/86 Primary

  slab-shaped · CPC title

• E04B2001/748

  Honeycomb materials · CPC title

• G10K11/168

  Plural layers of different materials, e.g. sandwiches · CPC title