초록 ▼

The present invention provides means of enhancing the acoustic attenuation and vibration damping of a material by (1) embedding a plurality of small particles of either a high characteristic acoustic impedance or a low characteristic acoustic impedance or combinations of high and low characteristic

The present invention provides means of enhancing the acoustic attenuation and vibration damping of a material by (1) embedding a plurality of small particles of either a high characteristic acoustic impedance or a low characteristic acoustic impedance or combinations of high and low characteristic acoustic impedance materials to form a matrix material to act as a acoustic attenuator or vibration damper; and (2) combing this matrix material with a second layer of a decoupling material that serves to effectively isolate the matrix material and reduce its tendency to vibrate sympathetically to the impinging acoustic energy. The mass of the resultant material may be very low while retaining excellent acoustic attenuation, vibration damping, and structural characteristics.

대표청구항 ▼

What is claimed is: 1. An acoustic attenuation and vibration damping material comprising: a first layer of a matrix material with a plurality of at least two species of particles incorporated therein, said particles being species differentiated by their characteristic acoustic impedances, and said

What is claimed is: 1. An acoustic attenuation and vibration damping material comprising: a first layer of a matrix material with a plurality of at least two species of particles incorporated therein, said particles being species differentiated by their characteristic acoustic impedances, and said particle species being proportionally distributed in said matrix material so that an increase in acoustic attenuating and vibration damping effect of said matrix material with said combination of at least two species of particles incorporated therein, relative to the acoustic attenuating and vibration damping effect of said matrix material with no particles incorporated therein, is greater than the sum of increases in acoustic attenuating and vibration damping effects of each particle species incorporated individually at the same concentration in said matrix material, relative to the acoustic attenuating and vibration damping effect of said matrix material with no particles incorporated therein, and a second layer of decoupling material that is at least partially in physical contact with said first layer, wherein said physical contact between said first layer and said second layer comprises less than ten percent of the surface area of said first layer. 2. The acoustic attenuation and vibration damping material of claim 1, wherein said second layer of decoupling material is comprised of an open-weave, low-density mat consisting of an inorganic fibrous material. 3. The acoustic attenuation and vibration damping material of claim 2, wherein said mat is composed of material selected from the group consisting of an organic polymer, an inorganic polymer, a polyester type material, a urethane type material, a silicone rubber type material, a natural fiber material, fiberglass, a composite fiber type material, and combinations thereof. 4. The acoustic attenuation and vibration damping material of claim 2, wherein said mat has flame-retardent qualities. 5. The acoustic attenuation and vibration damping material of claim 2, wherein said mat is a urethane type material. 6. The acoustic attenuation and vibration damping material of claim 1, wherein said matrix material is a urethane type material. 7. The acoustic attenuation and vibration damping material of claim 1, wherein said matrix material is a silicone rubber type material. 8. The acoustic attenuation and vibration damping material of claim 1, wherein said matrix material is an elastomer. 9. The acoustic attenuation and vibration damping material of claim 1, wherein said matrix material is a polymer. 10. The acoustic attenuation and vibration damping material of claim 1, wherein said matrix material is a petroleum extract. 11. The acoustic attenuation and vibration damping material of claim 1, wherein said matrix material is gypsum. 12. The acoustic attenuation and vibration damping material of claim 1, wherein one of said particle species is lead. 13. The acoustic attenuation and vibration damping material of claim 1, wherein one of said species of particles is of low impedance and another of said species of particles is of high impedance. 14. The acoustic attenuation and vibration damping material of claim 13, wherein said low impedance particle is cork and where said high impedance particle is steel. 15. The acoustic attenuation and vibration damping material of claim 1, wherein one of said particle species is glass micro spheres. 16. The acoustic attenuation and vibration damping material of claim 1, wherein one of said particle species is aluminum. 17. The acoustic attenuation and vibration damping material of claim 1, wherein one of said particle species is cork. 18. The acoustic attenuation and vibration damping material of claim 1, wherein said physical contact further comprises adherence of said second layer of decoupling material to said first layer. 19. The acoustic attenuation and vibration damping material of claim 18, wherein said commercially available adhesive is a type of epoxy cement. 20. The acoustic attenuation and vibration damping material of claim 18, wherein said commercially available adhesive is a type of non-corrosive glue. 21. The acoustic attenuation and vibration damping material of claim 1, wherein said first layer is adhered o said second layer by an adhesive between said first layer and said second layer. 22. The acoustic attenuation and vibration damping material of claim 1, wherein said adherence of said first layer to said second layer is accomplished by means of applying sufficient heat so tat the layers become at least partially physically connected. 23. A method of providing acoustic attenuation comprising reducing the sympathetic vibration between a substrate and sound attenuation materials by inserting a decoupling layer between said substrate and said sound attenuation material, wherein the sound attenuation material is comprised of the two layer acoustic attenuation and vibration damping material of claim 1. 24. The method of claim 23, wherein said second layer of decoupling material is comprised of an open-weave, low density mat consisting of an inorganic fibrous material. 25. The method of claim 23, wherein said sound attenuation material is adhered to said decoupling layer by an adhesive between said attenuation material and said decoupling layer. 26. The method of claim 23, wherein said matrix material is a polymer. 27. The method of claim 23, wherein one of said species of particles is of low impedance and another of said species of particles is of high impedance. 28. The method of claim 27, wherein said low impedance particle is cork and where said high impedance particle is steel.