CN217214139U - Switch type metamaterial unit cell and acoustic superstructure thereof - Google Patents

Abstract

The utility model discloses a switch-type metamaterial unit cell and acoustics superstructure thereof. The switch type metamaterial unit cell comprises a supporting part, a cavity part, a particle part and a regulating part, wherein the cavity part is arranged on the supporting part, the particle part is arranged in the cavity part, and the regulating part can be arranged at the upper end of the cavity part in an up-and-down moving mode; when the lower extreme of regulation and control portion and granule portion contact, the degree of freedom of motion that regulation and control portion is used for retraining granule portion, and nonlinear characteristic is in the closed condition, is equipped with the clearance between the lower extreme of regulation and control portion and granule portion, and regulation and control portion is used for releasing the degree of freedom of motion of granule portion, and nonlinear characteristic is in the open condition. The utility model discloses under the condition that need not rely on big deformation and big load excitation, easily aroused the nonlinear characteristic of metamaterial unit cell, improved the stability and the reliability of metamaterial unit cell nonlinear characteristic, overcome the not enough of the unable accurate conversion in metamaterial unit cell linearity and nonlinear stage, have simple structure, green, low cost's advantage.

Description

A switchable metamaterial cell and its acoustic superstructure

technical field

The utility model belongs to high-tech equipment (airplanes, rail trains, large ships, intelligent vehicles, new transmission and transformation systems, silent air conditioners, etc.), functional buildings (wind tunnels, highways, bridges/tunnels, passenger halls/halls, conference venues, Recording/studio halls, anechoic rooms, etc.) vibration and noise reduction new materials and new technologies, more specifically, a switch-type metamaterial cell and its acoustic superstructure.

Background technique

Acoustic metamaterial structure refers to a new type of acoustic material or structure composed of specially designed artificial acoustic microstructural units/cells (such as local resonance structural units, microvibrator units, or oscillators for short) arranged in an elastic medium in a predetermined manner. It can obtain extraordinary physical properties (such as negative mass density, negative refraction, and negative modulus) that natural materials do not have, and can realize extraordinary manipulation of elastic waves and sound waves, making it very important in many fields. Application value, such as acoustics Cloak, vibration isolation/shock resistance, vibration reduction and noise reduction, acoustic imaging, acoustic screen, etc.

The artificial acoustic microstructure unit is the basic unit for constructing acoustic metamaterials, which directly affects the extraordinary physical properties of acoustic metamaterials. The traditionally designed artificial acoustic microstructure units mainly include hard and soft material block oscillators, thin film concentrated mass oscillators, spiral labyrinth oscillators, double cantilever beam oscillators, and bistable buckling structures. Theoretically speaking, these artificial acoustic microstructure units have two stages: linear and nonlinear. When the structure works in the linear stage, it produces linear characteristics, and the structure is called linear structure at this time; when the structure works in the nonlinear stage, it produces nonlinear characteristics. Linear characteristics, the structure is also called nonlinear structure at this time; but in fact, most of these microstructure units work in the linear stage, and their inherent structure determines that they usually only produce linear characteristics. If you want to generate nonlinear characteristics, you need to Relying on large deformation or large load excitation, they are highly dependent on the outside world, which makes their nonlinear characteristics difficult to stably control, and these microstructure units cannot achieve accurate conversion between linear and nonlinear stages. These undoubtedly limit Industrial application of traditional artificial acoustic microstructure units.

Utility model content

The purpose of the present utility model is to provide a switch-type metamaterial cell and its acoustic superstructure to overcome the defects existing in the prior art.

In order to achieve the above object, the technical scheme adopted by the present utility model is as follows:

A switch-type metamaterial cell, comprising a support part, a cavity part, a particle part and a regulation part, the cavity part is arranged on the support part, the particle part is arranged in the cavity part, the The regulating part is arranged on the upper end of the cavity part which can move up and down; when the lower end of the regulating part is in contact with the particle part, the regulating part is used to constrain the freedom of movement of the particle part, and the switch The nonlinear characteristic of the metamaterial cell is in a closed state, and when a gap is set between the lower end of the regulating part and the particle part, the regulating part is used to release the freedom of movement of the particle part, and the The nonlinear properties of the switched metamaterial cells are turned on.

Further, a gap is provided between the particle portion and the inner wall of the cavity portion, the number of the particle portion is at least one, and a gap or contact is provided between adjacent particle portions.

Further, the regulating part includes a handle, a pressure block connected to the handle, the pressure block is located in the cavity part, and a lifting structure that drives the pressure block to move up and down along the cavity part through the handle, When the compact is in contact with the particle part, the regulation part is used to constrain the freedom of movement of the particle part, and the nonlinear characteristic of the switch-type metamaterial cell is in a closed state. When there is a gap with the particle part, the regulation part is used to release the freedom of movement of the particle part, and the nonlinear characteristic of the switch-type metamaterial cell is in an open state.

Further, the lifting structure includes an internal thread provided on the inner sidewall of the cavity portion, and an external thread provided on the pressing block, and the pressing block is connected to the internal thread of the cavity portion through the external thread. In cooperation, the handle is arranged along the tangential direction of the inner side wall of the cavity portion.

Further, the lifting structure includes a chute arranged on the side wall of the cavity portion, the handle is perpendicular to the direction of the inner side wall of the cavity portion and is connected to the pressing block after passing through the chute, The outer end of the handle is provided with a boss.

Further, the support portion is a solid elastic cylinder, a hollow elastic cylinder or a spring.

Further, the material of the support part is steel, aluminum, rubber, carbon fiber, polyurethane, nylon or asbestos, the material of the particle part is steel, copper, stone, plastic or silicon rubber, the cavity The material of the body is iron, steel, aluminum, copper or plastic.

The present invention also provides an acoustic superstructure, comprising a basic part and the above-mentioned switch-type metamaterial cell, wherein the switch-type metamaterial cell is arranged on the basic part or embedded in the basic part.

Further, there are at least two switch-type metamaterial cells, and a plurality of switch-type metamaterial cells are connected to the base portion according to a predetermined arrangement or embedded in the base portion according to a predetermined manner.

Further, the basic part is a homogeneous beam/slab structure, a reinforced beam/slab structure, a sandwich beam/slab structure, a carbon fiber composite beam/slab structure or a multi-layer composite beam/slab structure.

Compared with the prior art, the advantages of the present invention are: the cavity part in the present invention acts as the main mass effect of the metamaterial cell in the linear stage on the one hand, and is used to surround the particle part and act as the metamaterial cell on the other hand. The impacted body of the cell in the nonlinear stage; the particle part acts as the sub-mass role of the metamaterial cell in the linear stage on the one hand, and the main impactor role of the metamaterial cell in the nonlinear stage on the other hand; the support part on the one hand It supports the cavity part, the particle part and the regulation part and acts as the main stiffness of the metamaterial cell in the linear stage, and acts as a load input channel on the other hand; the regulation part mainly adjusts the particle part by adjusting the gap between it and the particle part The degree of freedom of movement can be restrained and released, so as to open or close the nonlinear characteristics of the metamaterial cell, and realize the precise conversion between the linear stage and the nonlinear stage of the metamaterial cell. The utility model easily excites the nonlinear characteristics of the metamaterial cells without relying on large deformation and large load excitation, greatly improves the stability and reliability of the non-linear characteristics of the metamaterial cells, and overcomes the It solves the problem that the linear and nonlinear stages of metamaterial cells cannot be accurately converted, and also has the advantages of simple structure, green environmental protection, and low cost.

Description of drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are just some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

In Figure 1, a is a schematic diagram of the helix-regulated metamaterial cell, and b is a schematic diagram of the chute-regulated metamaterial cell.

In Fig. 2, a is a schematic diagram of the number of particle parts in the present invention, b is a schematic diagram of two particle parts, and c is a schematic diagram of a plurality of particle parts.

In Fig. 3, a is a schematic diagram of the start of the switch-type metamaterial cell helical regulation of the present invention, and b is a schematic diagram of the downward movement of the regulating portion along the cavity portion.

In Fig. 4, a is a schematic diagram of the start of regulation of the switch-type metamaterial cell chute of the present invention, b is a schematic diagram when the handle and the cavity part are loosened when the chute is regulated, and c is the control part moving down along the chute of the cavity part Schematic.

In Fig. 5, a is a schematic diagram of the supporting part being a hollow elastic column in the present invention, and b is a schematic diagram that the supporting part is a spring.

FIG. 6 is a schematic diagram of an embodiment of the acoustic superstructure based on switch-type metamaterial cells of the present invention.

FIG. 7 is a plurality of combined diagrams of FIG. 6 .

FIG. 8 is a schematic diagram of another embodiment of the acoustic superstructure based on switch-type metamaterial cells of the present invention.

FIG. 9 is a schematic diagram of two embodiments of the cell arrangement of the switch-type metamaterial of the present invention.

FIG. 10 is a schematic diagram of an embodiment of the number and variation of the cell arrangement of the switch-type metamaterial of the present invention.

FIG. 11 is a vibration transfer curve of an embodiment of the switch-type metamaterial cell of the present invention.

In the figure: the support part 1, the cavity part 2, the particle part 3, the regulating part 4, the handle 4a, the pressing block 4b, the switch-type metamaterial cell 5, and the base part 6.

Detailed ways

The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, and the protection scope of the present invention can be more clearly defined.

Example 1

Referring to a of FIG. 1 , the present embodiment discloses a switch-type metamaterial cell 5 , which includes a support part 1 , a cavity part 2 , a particle part 3 and a regulation part 4 , wherein the cavity part 2 is arranged on the support On the part 1 , the particle part 3 is arranged in the cavity part 2 , that is, the particle part 3 is surrounded by the cavity part 2 , and the regulating part 4 is arranged on the upper end of the cavity part 2 which can move up and down.

When the lower end of the regulation part 4 is in contact with the particle part 3 (locally in contact), the regulation part 4 is used to constrain the freedom of movement of the particle part 3 , and the nonlinear characteristic of the switch-type metamaterial cell 5 is in a closed state. When there is a gap between the lower end of the particle part 3 and the particle part 3, the regulating part 4 is used to release the freedom of movement of the particle part 3, and the nonlinear characteristic of the switch-type metamaterial cell 5 is in an open state.

Specifically, on the one hand, the cavity part 2 acts as the main mass of the metamaterial cell in the linear stage, and on the other hand, it is used to surround the particle part 3 and act as the impacted body of the metamaterial cell in the nonlinear stage; the particle part 3 On the one hand, it acts as the sub-mass effect of the metamaterial cell in the linear stage, and on the other hand, it acts as the main shock body of the metamaterial cell in the nonlinear stage; on the one hand, the support part 1 supports the cavity part 2, the particle part 3 and the regulation part 4 and acts as the main stiffness effect of the metamaterial cell in the linear stage, and on the other hand acts as a load input channel; the regulation part 4 mainly adjusts the degree of freedom of movement of the particle part 3 by adjusting the gap between it and the particle part 3 to achieve Constraining and releasing the movement degrees of freedom of the particle part 3 plays the role of opening or closing the nonlinear characteristics of the metamaterial cell, and realizes the precise conversion between the linear stage and the nonlinear stage of the metamaterial cell. The switch-type metamaterial cell 5 can easily excite the nonlinear characteristics of the metamaterial cell without relying on large deformation and large load excitation, which greatly improves the stability of the nonlinear characteristic of the metamaterial cell. and reliability, and overcomes the deficiency that the metamaterial cell cannot be accurately converted in the linear and nonlinear stages. At the same time, the switch-type metamaterial cell 5 also has the advantages of simple structure, green environmental protection, and low cost.

In this embodiment, a gap is set between the particle part 3 and the inner wall of the cavity part 2, for example, the gap between the particle part 3 and the inner wall of the cavity part 2 is 0.3 mm, 2.6 mm, 10.0 mm, etc. Preferably, The gap between the particle part 3 and the inner side wall of the cavity part 2 is larger than the radius of the particle body.

In this embodiment, the number of the particle parts 3 is at least one (that is, greater than or equal to one), as shown in a, b, and c in FIG. 2 , for example, the number of particles in the particle part 3 may be an integer such as 1, 2, 9, etc. , and the adjacent particle parts 3 are provided with gaps or are in contact with each other. Preferably, each particle part 3 may be in point contact.

Specifically, the control part 4 in this embodiment includes a handle 4a, a pressure block 4b connected to the handle 4a, the pressure block 4b is located in the cavity part 2, and the pressure block 4b is driven by the handle 4a to move up and down along the cavity part 2 When the lifting structure makes the pressing block 4b contact with the particle part 3 (local contact), the regulating part 4 is used to constrain the freedom of movement of the particle part 3, and the nonlinear characteristics of the switch-type metamaterial cell 5 are in a closed state. , when the lifting structure sets a gap between the pressing block 4b and the particle part 3, the regulating part 4 is used to release the freedom of movement of the particle part 3, and the nonlinear characteristic of the switch-type metamaterial cell 5 is in an open state.

1a, the lifting structure of this embodiment includes an inner thread provided on the inner side wall of the cavity portion 2, and an outer thread provided on the pressing block 4b, and the pressing block 4b is connected to the cavity portion 2 through the external thread. The inner threads are matched, and the handle 4a is arranged along the tangential direction of the inner side wall of the cavity portion 2 . At this time, the pressing block 4 b of the regulating part 4 is connected to the inner side wall of the cavity part 2 , and the regulating part 4 can move up and down along the tangential direction of the inner wall of the cavity part 2 . With reference to a and b in FIG. 3 , the rotating handle 4 a can push the regulating part 4 to move up and down along the tangential direction of the inner side wall of the cavity part 2 .

Referring to a and b in FIG. 5 , the support portion 1 is a solid elastic cylinder, a hollow elastic cylinder or a spring.

In this embodiment, the support portion 1 is a steel support portion, an aluminum support portion, a rubber support portion, a carbon fiber support portion, a polyurethane support portion, a nylon support portion, an asbestos support portion, or the like.

In this embodiment, the particle part 3 is a steel particle part, a copper particle part, a stone particle part, a plastic particle part, a silicone rubber particle part, or the like.

In this embodiment, the cavity part 2 is an iron cavity part, a steel cavity part, an aluminum cavity part, a copper cavity part, a plastic cavity part, or the like.

In this embodiment, in order to achieve accurate conversion, a scale may be provided on the handle 4a or the cavity portion 2 . And can use manual control or electric drive control.

Figure 11 is a vibration transfer curve for an embodiment of a switched metamaterial cell.

Embodiment 2

Referring to b in FIG. 1 , other structures of this embodiment are the same as those of the first embodiment, the difference is that the lifting structure in this embodiment includes a chute provided on the side wall of the cavity portion 2 , and the handle 4a is perpendicular to the cavity The inner side wall of the body 2 is connected to the pressing block 4b after passing through the chute, and the outer end of the handle 4a is provided with a boss.

In this embodiment, there is a gap of 1.0 mm between the pressing block 4b of the regulating part 4 and the inner side wall of the cavity part 2, and the handle 4a is rotated to loosen the outer wall of the cavity part 2 and the boss of the handle 4a, and then push the The regulating part 4 moves up and down along the direction of the chute of the cavity part 2 .

Embodiment 3

Referring to FIG. 6 to FIG. 10 , the present embodiment provides an acoustic superstructure, including a basic part 6 , the switch-type metamaterial cell 5 in the first embodiment or the second embodiment, and the switch-type metamaterial cell 5 is arranged in the The base part 6 is on or embedded in the base part 6 .

In this embodiment, the number of switch-type metamaterial cells 5 is at least two, for example, the number is 5, 20, or 30, and a plurality of switch-type metamaterial cells 5 are connected to the base portion according to a predetermined arrangement. 6 or embedded in the base part 6 in a predetermined manner. For example, metamaterial cells are arranged in uniform grid points (as shown in Figures 7 and 8) or non-uniform grid points (as in Figure 9).

In this embodiment, each component (support part 1, cavity part 2, particle part 3 and regulation part 4) in each switch-type metamaterial cell 5 can be the same, or can be changed in a predetermined manner, for example, each supermaterial The height of the support part 1 in the material cell shows a trend of 4mm-2mm-0.5mm-4mm-2mm, and the number of particle parts 3 in the switching metamaterial cell 5 shows 27-9-17-12-25 changing trend.

Preferably, the basic part 6 is a homogeneous beam/plate structure, a reinforced beam/plate structure, a sandwich beam/plate structure, a carbon fiber composite beam/plate structure or a multi-layer composite beam/plate structure.

Embodiment 4

Referring to FIG. 4 to FIG. 6 , this embodiment provides an acoustic superstructure, including a basic part 6, a switch-type metamaterial cell 5 in the first or second embodiment, and the switch-type metamaterial cell 5 is arranged in the basic part 6 on.

In this embodiment, the base portion 6 is a beam-like structure made of aluminum alloy, the number of switch-type metamaterial cells 5 is 10, the cell spacing is 100 mm, and the cavity portion 2 is cylindrical, with a side chute, and a cavity. The number of particle parts in the body part 2 is 4, and the particle part 3 is a steel spherical structure with a diameter of 4 mm.

In this embodiment, the control part 4 is composed of a handle 4a and a pressing block 4b, the pressing block 4b is located in the cavity part 2, and a lifting structure is used to drive the pressing block 4b to move up and down along the cavity part 2 through the handle 4a. When the pressing block 4b is in contact with the particle part 3 (partial contact), the regulating part 4 is used to constrain the freedom of movement of the particle part 3, and the nonlinear characteristic of the switch-type metamaterial cell 5 is in a closed state. When the lifting structure makes the pressing block 4b When there is a gap with the particle part 3, the regulating part 4 is used to release the freedom of movement of the particle part 3, and the nonlinear characteristic of the switch-type metamaterial cell 5 is in an open state.

In this embodiment, the switch-type metamaterial cell 5 performs a vibration response test when the nonlinear characteristics are in the closed state and the open state, and through white noise excitation, the average vibration transmission on the upper surface of the beam-shaped basic portion 6 is measured. rate curve (see Figure 11), it can be seen from the figure that under the condition of equal mass, the vibration transfer curve in the frequency band of 0-1000Hz is attenuated when the nonlinear characteristic of the switching metamaterial cell 5 is turned on than when it is turned off, and at 200Hz -800Hz peak attenuation is greater than 8dB. It can be seen that the switch-type metamaterial structure of the present invention has a good low-frequency broadband absorbing effect.

The utility model can easily excite the nonlinear characteristics of the structure through the control part, and has flexible linear and nonlinear conversion functions, which can overcome the difficulty in excitation of the nonlinear characteristics of traditional artificial acoustic microstructure units, and the inability to accurately convert between linear and nonlinear stages. It has the advantages of simple structure and low cost.

Although the embodiments of the present invention are described in conjunction with the accompanying drawings, the patent owner can make various changes or modifications within the scope of the appended claims, as long as the protection scope described in the claims of the present invention is not exceeded, All should fall within the protection scope of the present invention.

Claims (10)

1. A switch-type metamaterial cell, characterized in that it comprises a support portion, a cavity portion, a particle portion and a regulation portion, wherein the cavity portion is arranged on the support portion, and the particle portion is arranged on the described support portion. In the cavity part, the regulating part is arranged on the upper end of the cavity part which can move up and down; when the lower end of the regulating part is in contact with the particle part, the regulating part is used to restrain the movement of the particle part degree of freedom, the nonlinear characteristic of the switch-type metamaterial cell is in a closed state, and when there is a gap between the lower end of the regulation part and the particle part, the regulation part is used to release the particle part. degrees of freedom of motion, the nonlinear properties of the switched metamaterial cells are turned on. 2 . The switch-type metamaterial cell according to claim 1 , wherein a gap is provided between the particle portion and the inner wall of the cavity portion, and the number of the particle portion is at least one, and the number of the particle portion is at least one. A gap or contact is provided between the adjacent particle parts. 3 . The switch-type metamaterial cell according to claim 1 , wherein the regulating part comprises a handle, a pressing block connected with the handle, the pressing block is located in the cavity part, and the pressure block is connected through the The handle drives the pressing block to move up and down along the cavity part. When the pressing block is in contact with the particle part, the regulating part is used to constrain the freedom of movement of the particle part. The non-linear characteristic of the metamaterial cell is in a closed state, and when a gap is set between the compact and the particle part, the regulating part is used to release the freedom of movement of the particle part, and the on-off super Nonlinear properties for material cells are turned on. 4 . The switch-type metamaterial cell according to claim 3 , wherein the lifting structure comprises an internal thread provided on the inner sidewall of the cavity portion, and an external thread provided on the pressing block, 5 . The pressing block is matched with the inner thread of the cavity part through the outer thread, and the handle is arranged along the tangential direction of the inner side wall of the cavity part. 5 . The switch-type metamaterial cell according to claim 3 , wherein the lifting structure comprises a chute provided on the side wall of the cavity, and the handle is perpendicular to the inner side of the cavity. 6 . The wall is connected to the pressing block after passing through the chute, and the outer end of the handle is provided with a boss. 6 . The switch-type metamaterial cell according to claim 1 , wherein the support portion is a solid elastic cylinder, a hollow elastic cylinder or a spring. 7 . 7. The switch-type metamaterial cell according to claim 1, wherein the material of the support portion is steel, aluminum, rubber, carbon fiber, polyurethane, nylon or asbestos, and the material of the particle portion is Steel, copper, stone, plastic or silicon rubber, the material of the cavity is iron, steel, aluminum, copper or plastic. 8. An acoustic superstructure, characterized in that it comprises a base part and the switch-type metamaterial cell according to any one of claims 1-7, wherein the switch-type metamaterial cell is provided on the base part or embedded within the base. 9 . The acoustic superstructure according to claim 8 , wherein there are at least two switch-type metamaterial cells, and a plurality of switch-type metamaterial cells are connected to the base part according to a predetermined arrangement. 10 . Or embedded in the base part in a predetermined manner. 10. The acoustic superstructure of claim 8, wherein the base part is a homogeneous beam/slab structure, a reinforced beam/slab structure, a sandwich beam/slab structure, a carbon fiber composite beam/slab structure or Multilayer composite beam/slab structure.

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