Superscattering of plate bending wave

Patent metadata

Field	Value
Publication number	US-11448281-B2
Application number	US-202017067102-A
Country	US
Kind code	B2
Filing date	Oct 9, 2020
Priority date	Oct 9, 2020
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

Devices for superscattering a plate bending wave include a solid plate, and a circular array of spring-mass resonators positioned on a surface of the plate. All resonators in the circular array have a resonance frequency that can be matched to a frequency of a target flexural wave. The circular array has a diameter that can further be matched to the wavelength of the target flexural wave. Scattering efficiencies can exceed several multiples of the theoretical limit.

First claim

What is claimed is:

1. A device for superscattering a flexural wave, the device comprising:
a plate; and
a circular array of spring-mass resonators positioned on the plate, the array having N degrees of rotational symmetry about a center point, where N is the number of resonators in the array.

2. The device as recited in claim 1 , wherein N is six.

3. The device as recited in claim 1 , wherein the plate has a minimum lateral dimension that is equal to or greater than six-times a diameter defined by the circular array of spring-mass resonators.

4. The device as recited in claim 1 , wherein each spring-mass resonator comprises:
a spring portion connected to the plate and formed of a resilient element having a spring constant, k; and
a mass portion supported by the spring portion and having a mass, m,

wherein each spring-mass resonator has a resonance frequency, f 0 , according to an equation:

f
0

=

1

2
⁢
π

⁢

k
m

,

and each spring-mass resonator of the plurality has substantially the same resonance frequency.

5. The device as recited in claim 4 , wherein each resonator of the circular array has substantially the same spring constant, k, and mass, m.

6. The device as recited in claim 1 , wherein each resonator of the circular array is substantially identical.

7. The device as recited in claim 1 , comprising a flexural wave source positioned on the plate at a distance from the circular array, and operable to generate a target flexural wave having wavelength, A, such that the target flexural wave propagates from the flexural wave source to the circular array, defining a propagation direction.

8. The device as recited in claim 7 , wherein each resonator of the circular array has a resonance frequency, f 0 , that corresponds to the wavelength, λ, of the target flexural wave by an equation:

λ
=

2
⁢
π
⁢

D

ρ
⁢

⁢

t
⁡

(

2
⁢
π
⁢

f
0

)

2

4

,

wherein ρ is plate density, t is plate thickness, and D is plate bending stiffness.

9. The device as recited in claim 7 , wherein the circular array defines a diameter, d, that is substantially equal to λ/2.

10. The device as recited in claim 7 , wherein the plate has a width, w, perpendicular to the propagation direction, the width being greater than or equal to 3λ.

11. A vehicle having a device for superscattering a flexural wave, the vehicle comprising:
a structural plate of the vehicle; and
a circular array of spring-mass resonators positioned on the plate, the array having N degrees of rotational symmetry about a center point, where N is the number of resonators in the array.

12. The vehicle as recited in claim 11 , wherein the structural plate is a floorboard.

13. The vehicle as recited in claim 11 , wherein the structural plate is a floor of an engine compartment.

14. The vehicle as recited in claim 11 , wherein the structural plate is a truck bed.

15. The vehicle as recited in claim 11 , wherein N is six.

16. The vehicle as recited in claim 11 , wherein the plate has a minimum lateral dimension that is equal to or greater than six-times a diameter defined by the circular array of spring-mass resonators.

17. The vehicle as recited in claim 11 , wherein each spring-mass resonator comprises:
a spring portion connected to the plate and formed of a resilient element having a spring constant, k; and
a mass portion supported by the spring portion and having a mass, m,

wherein each spring-mass resonator has a resonance frequency, f 0 , according to an equation:

f
0

=

1

2
⁢
π

⁢

k
m

,

and each spring-mass resonator of the plurality has substantially the same resonance frequency.

18. The vehicle as recited in claim 17 , wherein each resonator of the circular array has substantially the same spring constant, k, and mass, m.

19. The vehicle as recited in claim 11 , wherein each resonator of the circular array is substantially identical.

20. The vehicle as recited in claim 11 , comprising a flexural wave source positioned on the plate at a distance from the circular array, and operable to generate a target flexural wave having wavelength, λ, such that the target flexural wave propagates from the flexural wave source to the circular array, defining a propagation direction.

Assignees

• Toyota Eng & Mfg North America

Inventors

• Lee Taehwa
• Iizuka Hideo

Classifications

• B62D33/02

  Platforms; Open load compartments {(flat wagons including posts or standards B61D3/08)} · CPC title

• F16F7/116

  on metal springs · CPC title

• B62D25/20

  Floors or bottom sub-units {(sub-frames for mounting engine or suspensions B62D21/11; drip trays F16N31/006)} · CPC title

• F16F7/108 Primary

  on plastics springs · CPC title

• B62D37/02

  by aerodynamic means · CPC title