Negative Poisson's ratio structure and damping device

Abstract

The invention discloses a negative Poisson's ratio structure and a damping device, and the negative Poisson's ratio structure comprises a plurality of ring parts which are arranged at intervals; any two adjacent ring parts are connected through the connecting beams, the connecting beams extend in the tangential direction of the ring parts, and at least one side in the thickness direction of the middle part of at least part of the connecting beams in the length direction is provided with a concave part. According to the negative Poisson's ratio structure disclosed by the invention, the acoustic black hole structure is formed at the concave part of the connecting beam, so that the propagation speed of mechanical waves in the negative Poisson's ratio structure is effectively reduced, the reflection at the tail end of a boundary is obviously reduced, an area with high energy density is formed, the negative Poisson's ratio structure is optimized, and the vibration and noise reduction effects are enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of vibration reduction, and in particular to a negative Poisson's ratio structure and a vibration reduction device. Background Art

[0002] Negative Poisson's ratio structure is a special material or design, which is characterized by the fact that when subjected to tensile force, the material not only stretches in the direction of the applied force, but also expands in the direction perpendicular to the applied force; on the contrary, when subjected to compressive force, the material shrinks in the perpendicular direction. This structure is completely opposite to the behavior of conventional positive Poisson's ratio materials (that is, the material shrinks when stretched and expands when compressed).

[0003] Therefore, negative Poisson's ratio structures are often used in vibration reduction structures and have good vibration reduction effects. However, the vibration reduction and energy absorption effects of different negative Poisson's ratio structures vary greatly. It is necessary to optimize and improve the negative Poisson's ratio structure so that it can achieve better vibration reduction and energy absorption effects. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a negative Poisson's ratio structure, which optimizes the negative Poisson's ratio structure and enhances the effect of vibration reduction and noise reduction.

[0005] The present invention also provides a vibration reduction device, comprising the above-mentioned negative Poisson's ratio structure

[0006] According to an embodiment of the present invention, the negative Poisson's ratio structure includes: a ring portion, which is a plurality of spaced-apart ring portions; a connecting beam, through which any two adjacent ring portions are connected, the connecting beam extends along the tangential direction of the ring portion, and at least one side of the middle portion in the length direction of the connecting beam in the thickness direction has a recessed portion.

[0007] According to the negative Poisson's ratio structure of the embodiment of the present invention, any two adjacent ring portions are connected by a connecting beam, the connecting beam extends along the tangential direction of the ring portion, and at least one side of the middle portion in the length direction of at least part of the connecting beam in the thickness direction has a recessed portion, so that the recessed portion of the connecting beam forms an acoustic black hole structure, thereby effectively reducing the propagation speed of mechanical waves in the negative Poisson's ratio structure, significantly reducing the reflection at the boundary end, forming a region with high energy density, optimizing the negative Poisson's ratio structure, and enhancing the vibration reduction and noise reduction effect.

[0008] In some embodiments of the present invention, the distance between the point x located on the inner wall of the concave portion and the center plane of the connecting beam in the thickness direction is h(x), h(x)=Ax m +h min, where x≥0, m≥2, x is the minimum distance between the projection of the lowest point of the concave portion on the central plane and the projection of point x on the central plane, h min It is the distance between the lowest point of the concave portion and the center plane of the connecting beam in the thickness direction, and the lowest point of the concave portion is higher than the center plane of the connecting beam in the thickness direction.

[0009] In some embodiments of the present invention, the maximum thickness of the connecting beam is h, h / 10≤h min ≤h / 5, and 1mm≤h min .

[0010] In some embodiments of the present invention, there are two recessed portions, and the two recessed portions are respectively disposed on two sides of the connecting beam in a thickness direction and are arranged opposite to each other.

[0011] In some embodiments of the present invention, the negative Poisson's ratio structural unit further includes: a damping layer, wherein the damping layer is disposed in the recessed portion, and the damping layer covers at least a portion of an inner wall surface of the recessed portion.

[0012] In some embodiments of the present invention, the damping layer is a rubber layer or a foam layer.

[0013] In some embodiments of the present invention, the plurality of ring portions are arranged in multiple rows and columns.

[0014] In some embodiments of the present invention, two adjacent ring portions in the same column are connected via one connecting beam; and / or two adjacent ring portions in the same row are connected via one connecting beam.

[0015] In some embodiments of the present invention, a plurality of connecting beams spaced apart along the circumferential direction of the ring portion are connected to the peripheral wall of the ring portion, the plurality of connecting beams include at least one group of connecting beams, and each group of connecting beams includes two connecting beams that are relatively arranged in parallel in the radial direction of the ring portion and extend in opposite directions.

[0016] The vibration reduction device according to the embodiment of the present invention includes the above-mentioned negative Poisson's ratio structure.

[0017] According to the vibration reduction device of the embodiment of the present invention, by setting the above-mentioned negative Poisson's ratio structure, any two adjacent ring parts are connected by a connecting beam, the connecting beam extends along the tangential direction of the ring part, and at least one side of the middle part in the length direction of at least part of the connecting beam in the thickness direction has a recessed portion, so that the recessed portion of the connecting beam forms an acoustic black hole structure, thereby effectively reducing the propagation speed of mechanical waves in the negative Poisson's ratio structure, significantly reducing the reflection at the boundary end, forming a region with high energy density, optimizing the negative Poisson's ratio structure, and enhancing the vibration reduction and noise reduction effect.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 is a front view of a negative Poisson's ratio structure according to an embodiment of the present invention;

[0021] Figure 2 is a partial enlarged view of a negative Poisson's ratio structure according to an embodiment of the present invention;

[0022] Figure 3 Schematic diagram of a connecting beam of a negative Poisson's ratio structure according to an embodiment of the present invention.

[0023] Reference numerals:

[0024] 10. Negative Poisson's ratio structure;

[0025] 1. Ring;

[0026] 2. connecting beam; 21. recessed portion;

[0027] 3. Damping layer;

[0028] 4. Center plane;

[0029] 5. Connecting plate. DETAILED DESCRIPTION

[0030] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] Reference below Figure 1-Figure 3 A negative Poisson's ratio structure 10 according to an embodiment of the present invention is described.

[0034] like Figure 1-Figure 3 As shown, the negative Poisson's ratio structure 10 according to an embodiment of the present invention includes: a ring portion 1 and a connecting beam 2 .

[0035] Specifically, refer to Figure 1-Figure 3 Any two adjacent ring portions 1 are connected by a connecting beam 2, which extends along the tangential direction of the ring portion 1, and at least one side of the middle portion of the length direction of the connecting beam 2 in the thickness direction has a recessed portion 21.

[0036] It can be understood that at least one side of the middle part of the length direction of the connecting beam 2 has a concave portion 21, and the inner wall surface of the concave portion 21 is a curved surface, thereby forming an acoustic black hole structure at the concave portion 21 of the connecting beam 2, thereby effectively reducing the propagation speed of mechanical waves (especially bending waves) at the concave portion 21, thereby reducing the propagation speed of mechanical waves at the connecting beam 2, thereby reducing the propagation speed of mechanical waves between multiple ring portions 1, significantly reducing the reflection at the end of the boundary, forming a region with high energy density, thereby enhancing the effect of vibration reduction and noise reduction. As a result, the negative Poisson's ratio structure 10 is optimized and the vibration reduction and noise reduction effect of the negative Poisson's ratio structure 10 is enhanced.

[0037] Furthermore, if Figure 2 and Figure 3 As shown, along the length direction of the connecting beam 2, the thickness of the connecting beam 2 at the recessed portion 21 first decreases and then increases, thereby allowing a recessed portion 21 of the connecting beam 2 to be formed into two acoustic black hole structures connected along the length direction of the connecting beam 2. Through the joint action of the two acoustic black hole structures, the propagation speed of the mechanical waves in the negative Poisson's ratio structure 10 is further reduced, and the reflection at the boundary end is significantly reduced, thereby further enhancing the vibration reduction and noise reduction effect.

[0038] According to the negative Poisson's ratio structure 10 of the embodiment of the present invention, any two adjacent ring portions 1 are connected by a connecting beam 2, the connecting beam 2 extends along the tangential direction of the ring portion 1, and at least one side of the middle portion in the length direction of at least part of the connecting beam 2 in the thickness direction has a recessed portion 21, so that the recessed portion 21 of the connecting beam 2 forms an acoustic black hole structure, thereby effectively reducing the propagation speed of mechanical waves in the negative Poisson's ratio structure 10, significantly reducing the reflection at the boundary end, forming a region with high energy density, optimizing the negative Poisson's ratio structure 10, and enhancing the vibration reduction and noise reduction effect.

[0039] In some embodiments of the present invention, Figure 3 As shown, the distance between the point x located on the inner wall of the concave portion 21 and the center plane 4 in the thickness direction of the connecting beam 2 is h(x), h(x)=Ax m +h min , where x≥0, m≥2, x is the minimum distance between the projection of the lowest point of the recessed portion 21 on the center plane 4 and the projection of point x on the center plane 4, hmin is the distance between the lowest point of the recessed portion 21 and the center plane 4 in the thickness direction of the connecting beam 2, and the lowest point of the recessed portion 21 is higher than the center plane 4 in the thickness direction of the connecting beam 2.

[0040] It can be understood that the distance between the point x located on the inner wall of the concave portion 21 and the center plane 4 in the thickness direction of the connecting beam 2 is h(x), and h(x)=Ax m +h min , so that the connecting beam 2 at the concave portion 21 can obey the power law distribution, thereby better forming an acoustic black hole structure, so that the acoustic black hole properties are better utilized, thereby further reducing the propagation speed of mechanical waves in the negative Poisson's ratio structure 10, significantly reducing the reflection at the end of the boundary, forming a region with high energy density, optimizing the negative Poisson's ratio structure 10, and enhancing the effect of vibration reduction and noise reduction. At the same time, according to the change of the function, the connecting beam 2 can also be designed and manufactured more accurately.

[0041] Furthermore, if Figure 3As shown, the lowest point of the recessed portion 21 is higher than the center plane 4 in the thickness direction of the connecting beam 2, that is, the distance between the lowest point of the recessed portion 21 and the center plane 4 in the thickness direction of the connecting beam 2 is greater than 0. Therefore, when the middle part of the length direction of the connecting beam 2 has recessed portions 21 on both sides of the thickness direction, it can avoid that the connecting beam 2 is cut off by two recessed portions 21.

[0042] It should be noted that when the connecting beam 2 at the recessed portion 21 is formed into a one-dimensional acoustic black hole structure (such as the present invention), the recessed portion 21 of the connecting beam 2 penetrates the connecting beam 2 along the width direction of the connecting beam 2; when the connecting beam 2 at the recessed portion 21 is formed into a two-dimensional acoustic black hole structure, the recessed portion 21 is formed into a conical concave surface. One-dimensional acoustic black holes and two-dimensional acoustic black holes are familiar to those skilled in the art and will not be described in detail here.

[0043] In some embodiments of the present invention, the maximum thickness of the connecting beam 2 is h, where h / 10≤h min ≤h / 5, for example h min It can be h / 10, 3h / 20 or h / 5, etc., thereby ensuring the strength of the connecting beam 2 at the lowest point of the recessed portion 21 on the one hand, and ensuring a good truncation effect on the mechanical wave on the other hand.

[0044] Furthermore, 1mm≤h min For example, hmin can be 1mm, 2mm, 3mm or 4mm, etc., which facilitates the processing of the process.

[0045] In some embodiments of the present invention, Figure 1-Figure 3 As shown, there are two concave portions 21, which are respectively arranged on both sides of the thickness direction of the connecting beam 2 and are arranged opposite to each other. As a result, both sides of the thickness direction of the connecting beam 2 can form an acoustic black hole structure, thereby further reducing the propagation speed of mechanical waves in the negative Poisson's ratio structure 10, significantly reducing the reflection at the boundary end, forming a region with high energy density, optimizing the negative Poisson's ratio structure 10, and enhancing the effect of vibration reduction and noise reduction.

[0046] In some embodiments of the present invention, Figure 2 and Figure 3 As shown, the negative Poisson's ratio structure 10 unit also includes: a damping layer 3, which is arranged in the recessed portion 21, and the damping layer 3 covers at least a portion of the inner wall surface of the recessed portion 21. It can be understood that the damping layer 3 can effectively dissipate the energy of mechanical waves. When the mechanical wave enters the acoustic black hole structure and is guided to the damping layer 3, the damping material absorbs part of the energy of the mechanical wave and converts it into heat energy. The presence of the damping layer 3 reduces the reflection of the sound wave inside the acoustic black hole structure, which means that fewer sound waves are reflected back into the environment, thereby reducing the noise level.

[0047] Furthermore, if Figure 2 and Figure 3 As shown, the number of the damping layers 3 is equal to the number of the concave portions 21 . For example, in the present invention, there are two concave portions 21 , and there are also two damping layers 3 corresponding to the two concave portions 21 .

[0048] In some embodiments of the present invention, the damping layer 3 is a rubber layer or a foam layer, wherein the foam layer may be a VHB (Very High Bonding) foam layer.

[0049] In some embodiments of the present invention, the thickness of the damping layer 3 is h min 2-4 times, for example, 2 times, 3 times, 3.5 times or 4 times, thereby ensuring the thickness of the damping layer 3, thereby ensuring the absorption effect of the damping layer 3 on mechanical waves, and further ensuring the noise reduction and vibration reduction effects.

[0050] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, the multiple ring parts 1 are arranged in multiple rows and columns, so that the negative Poisson's ratio structure 10 can absorb energy in multiple directions, thereby improving the vibration reduction effect.

[0051] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, two adjacent ring parts 1 in the same row are connected by a connecting beam 2; thus, the arrangement of the connecting beam 2 can be reduced, which on the one hand ensures the deformation space of the negative Poisson's ratio structure 10 and the vibration reduction effect, and on the other hand can reduce the cost.

[0052] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, two adjacent ring parts 1 in the same row are connected by a connecting beam 2. Thus, the number of connecting beams 2 can be reduced, which ensures the deformation space of the negative Poisson's ratio structure 10 and the vibration reduction effect, and reduces the cost.

[0053] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, a plurality of connecting beams 2 spaced apart along the circumferential direction of the ring portion 1 are connected to the peripheral wall of the ring portion 1, the plurality of connecting beams 2 include at least one group of connecting beams 2, and each group of connecting beams 2 includes two connecting beams 2 which are arranged parallel to each other in the radial direction of the ring portion 1 and extend in opposite directions.

[0054] It can be understood that, through the above-mentioned setting, when the negative Poisson's ratio structure 10 is stretched and deformed in a certain direction, two connecting beams 2 in one group of connecting beams 2 will be deformed and moved in a direction away from each other, thereby driving the ring part 1 to rotate and deform, so that the two connecting beams 2 in the remaining group of connecting beams 2 are deformed and moved in a direction away from each other, so that the negative Poisson's ratio structure 10 will also be deformed and stretched in another direction. Therefore, through this deformation motion transmission, internal friction is generated during deformation, and the vibration energy is converted into heat energy through the internal friction, thereby achieving a vibration reduction effect.

[0055] Below Figure 2 The example shown is used to describe the stress deformation of the negative Poisson's ratio structure 10. For example, in the present invention, two groups of connecting beams 2 are connected to the peripheral wall of each ring portion 1, namely a first group of connecting beams 2 and a second group of connecting beams 2. The first group of connecting beams 2 includes two connecting beams 2 on both sides of the ring portion 1 in the up and down directions, and the second group of connecting beams 2 includes two connecting beams 2 on both sides of the ring portion 1 in the left and right directions. When the negative Poisson's ratio structure 10 is pulled in the left and right directions, the two connecting beams 2 in the second group of connecting beams 2 are deformed and moved away from each other, thereby making the negative Poisson's ratio structure 10 as a whole longer in the left and right directions. At this time, the movement of the second group of connecting beams 2 causes the rotational deformation of the ring portion 1, thereby driving the two connecting beams 2 in the first group of connecting beams 2 to deform and move away from each other, thereby making the negative Poisson's ratio structure 10 as a whole longer in the up and down directions.

[0056] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, the negative Poisson's ratio structure 10 also includes: a connecting plate 5, two connecting plates 5, the two connecting plates 5 are arranged opposite to each other and spaced apart, a plurality of ring portions 1 and a plurality of connecting beams 2 are arranged between the two connecting plates 5, and the ring portion 1 closest to the connecting plate 5 is connected to the connecting plate 5 through the connecting beam 2.

[0057] The following describes a vibration reduction device according to an embodiment of the present invention.

[0058] The vibration reduction device according to the embodiment of the present invention includes the negative Poisson's ratio structure 10 described above.

[0059] According to the vibration reduction device of the embodiment of the present invention, by setting the above-mentioned negative Poisson's ratio structure 10, any two adjacent ring portions 1 are connected by a connecting beam 2, the connecting beam 2 extends along the tangential direction of the ring portion 1, and at least one side of the middle part of the length direction of at least part of the connecting beam 2 in the thickness direction has a recessed portion 21, so that the recessed portion 21 of the connecting beam 2 is formed into an acoustic black hole structure, thereby effectively reducing the propagation speed of mechanical waves in the negative Poisson's ratio structure 10, significantly reducing the reflection at the boundary end, forming a region with high energy density, optimizing the negative Poisson's ratio structure 10, and enhancing the vibration reduction and noise reduction effect.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0061] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A negative Poisson's ratio structure, characterized in that: include: a ring portion, the ring portion being a plurality of spaced-apart ring portions; A connecting beam is provided to connect any two adjacent ring portions, the connecting beam extends along the tangential direction of the ring portion, and at least one side of the middle portion in the length direction of the connecting beam and in the thickness direction has a recessed portion.

2. The negative Poisson's ratio structure according to claim 1, characterized in that: The distance between the point x on the inner wall of the concave portion and the center plane of the connecting beam in the thickness direction is h(x), h(x)=Ax m +h min , where x≥0, m≥2, x is the minimum distance between the projection of the lowest point of the concave portion on the central plane and the projection of point x on the central plane, h min It is the distance between the lowest point of the concave portion and the center plane of the connecting beam in the thickness direction, and the lowest point of the concave portion is higher than the center plane of the connecting beam in the thickness direction.

3. The negative Poisson's ratio structure according to claim 2, characterized in that: The maximum thickness of the connecting beam is h, h / 10≤h min ≤h / 5, and 1mm≤h min .

4. The negative Poisson's ratio structure according to claim 1, characterized in that: There are two recessed portions, which are respectively arranged on two sides of the connecting beam in the thickness direction and are arranged opposite to each other.

5. The negative Poisson's ratio structure according to claim 1, characterized in that: The negative Poisson's ratio structure also includes: A damping layer is disposed in the concave portion, and the damping layer covers at least a portion of an inner wall surface of the concave portion.

6. The negative Poisson's ratio structure according to claim 5, characterized in that: The damping layer is a rubber layer or a foam layer.

7. The negative Poisson's ratio structure according to claim 1, characterized in that: The plurality of ring portions are arranged in a plurality of rows and columns.

8. The negative Poisson's ratio structure according to claim 7, characterized in that: Two adjacent ring parts in the same row are connected by a connecting beam; And / or, two adjacent ring parts in the same row are connected by a connecting beam.

9. The negative Poisson's ratio structure according to claim 1, characterized in that: A plurality of connecting beams spaced apart along the circumferential direction of the ring portion are connected to the peripheral wall of the ring portion, the plurality of connecting beams include at least one group of connecting beams, and each group of connecting beams includes two connecting beams which are arranged parallel to each other in the radial direction of the ring portion and extend in opposite directions.

10. A vibration reduction device, characterized in that: Comprising the negative Poisson's ratio structure according to any one of claims 1-9.

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