A metamaterial device with non-local multi-tunable particle damping for wide low-frequency vibration reduction

Abstract

The present invention discloses a non-local multiple adjustable particle damping wide low-frequency vibration reduction metamaterial device, comprising a base plate, triangular particle damping, spherical particle damping, an enclosure structure and a non-local connecting device; the base plate is divided into six damping areas; each damping area includes more than four triangular particle damping, each triangular particle damping includes an upper triangular particle damping unit, a middle triangular particle damping unit and a lower triangular particle damping unit, and each layer of particle damping unit is provided with a spherical particle damping; an enclosure structure is provided on the outside of each damping area, and a vibration isolation frequency band control device is provided in the enclosure structure; a vibration transmission device is provided between each damping area, between the triangular particle damping in each damping area, between the spherical particle damping in each damping area, and between each enclosure structure and the corresponding damping area; the non-local connecting device is used to connect the triangular particle damping in two damping areas separated by one damping area.

Description

Technical Field

[0001] The present invention belongs to the technical field of engineering vibration isolation and noise reduction, and in particular relates to a non-local multiple adjustable particle damping wide low-frequency vibration reduction metamaterial device. Background Art

[0002] Metamaterials are a class of materials that exhibit mechanical properties not found in nature through the careful design of their internal structures. Their physical properties are primarily determined by their structure, rather than the properties of their constituent materials. In the 21st century, with the advancement of computer simulation and manufacturing technologies (such as 3D printing), the design and precision manufacturing of complex structures has become possible, and research on mechanical metamaterials has rapidly advanced. The application of mechanical metamaterials in band gaps holds great promise. Through careful design and manufacturing, precise control of waves can be achieved, thereby promoting the development of related technologies and applications. These materials, through the design of their internal structures, prevent the propagation of mechanical waves (such as acoustic and elastic waves) within certain frequency ranges, enabling the control and modulation of these waves. This has important applications in noise control, vibration isolation, waveguide design, energy harvesting, and other areas.

[0003] Particle damping is a passive vibration reduction technology that uses granular materials to dissipate vibration energy. A particle damping system consists of a closed chamber containing freely moving particles. When the system is subjected to vibration, collisions and friction occur between the particles within the chamber and between the particles and the chamber walls, converting the vibration energy into heat or other forms of energy dissipation. When vibration causes the particles to move, frequent collisions between the particles and between the particles and the chamber walls dissipate energy. This dissipation is primarily dependent on the particle velocity and collision frequency. The particles generate friction during their movement, which also dissipates vibration energy into heat. The energy dissipation efficiency of particle damping is closely related to the particle material, shape, size, density, packing ratio, and chamber design. Optimizing these parameters can significantly improve the damping effect. It is widely used in aerospace, automotive engineering, construction, and machinery manufacturing. Currently, particle damping mainly consists of bulk particle damping, layered particle damping, and embedded particle damping. However, the maximum efficiency of particle damping in dissipating vibration energy has not yet been achieved. Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of the prior art by providing a non-local, multi-adjustable particle damping metamaterial device for wide, low-frequency vibration reduction. This device enhances the particle damping's ability to dissipate vibration energy through collision and friction, achieving wide, low-frequency vibration isolation. By fully leveraging the collision and friction energy dissipation properties of particle damping, the present invention designs a non-local, multi-adjustable particle damping metamaterial device for wide, low-frequency vibration reduction, maximizing the efficiency of particle damping's energy dissipation properties.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A non-local multi-adjustable particle damping wide low-frequency vibration reduction metamaterial device comprises a base plate, a triangular particle damper, a spherical particle damper, an enclosure structure and a non-local connection device; the base plate is a regular hexagonal structure, and a partition structure is fixed to the base plate, the partition structure is installed along the diagonal of the hexagon and divides the metamaterial device into six damping areas; each damping area includes four or more triangular particle dampers, each triangular particle damper includes an upper triangular particle damping unit, a middle triangular particle damping unit and a lower triangular particle damping unit, and each layer of particle damping unit is provided with a spherical particle damper; an enclosure structure is provided on the outside of each damping area, and a vibration isolation frequency band control device is provided in the enclosure structure; a vibration transmission device is provided between each damping area, between the triangular particle dampers in each damping area, between the spherical particle dampers in each damping area, and between each enclosure structure and the corresponding damping area; the vibration transmission device comprises a spring and a rectangular connecting rod;

[0007] The non-local connection device is used to connect the triangular particle dampers in two damping areas separated by one damping area, and there is no vibration transmission device directly connected between each triangular particle damper and the adjacent damping area.

[0008] Furthermore, the upper triangular particle damping units and the lower triangular particle damping units are larger than the middle triangular particle damping units, and each triangular particle damping unit is provided with a cavity for placing the spherical particle damper.

[0009] Furthermore, the walls of the upper triangular particle damping unit and the lower triangular particle damping unit are both provided with rectangular openings; the height of the rectangular openings is smaller than the diameter of each spherical particle of the spherical particle damping;

[0010] The middle-layer triangular particle damping units in the same damping area are connected to each other through springs, and three springs are used between the walls of two opposite middle-layer triangular particle damping units;

[0011] The lower triangular particle damping units in different damping areas are connected to each other through springs;

[0012] The spherical damping particles in all adjacent upper triangular particle damping units in different damping areas and the same damping area are connected by rectangular connecting rods.

[0013] Furthermore, the cavity bottom surfaces of the upper triangular particle damping unit, the middle triangular particle damping unit and the lower triangular particle damping unit are set as inclined surfaces. When the spherical particle dampers are stationary inside the triangular particle damping units of each layer, they can move closer to each other to ensure that the spherical particle dampers fully collide with each other during vibration.

[0014] Furthermore, the triangular particle damper is placed horizontally on the bottom plate, and the upper surface of the bottom plate and the lower surface of the triangular particle damper are designed to be relatively rough so as to provide friction between each other during vibration and consume vibration energy.

[0015] Furthermore, the enclosure structure includes a fixed baffle, a limiting bolt, a movable baffle, an adjusting spring A, an adjusting spring B, a measuring ruler and a spherical particle limiting plate. The spherical particle limiting plate is arranged inside the upper triangular particle damping unit and the lower triangular particle damping unit close to the enclosure structure. The outer wall of the spherical particle limiting plate is connected to the movable baffle through the adjusting spring A. The inner wall of the movable baffle is provided with a protruding structure, and the outer wall is provided with a limiting structure. The limiting structure is provided with a fixed gasket and a limiting bolt, and a measuring ruler is fixed through the fixed gasket. The limiting bolt is sleeved with an adjusting spring B, one end of the adjusting spring B contacts the fixed baffle, and the other end contacts the limiting structure; the end of the limiting bolt passes through the bolt hole on the fixed baffle and is fixed by a nut, and the fixed baffle is fixed to the outermost side of the bottom plate; the movable baffle, limiting bolt, adjusting spring A, adjusting spring B, measuring ruler and spherical particle limiting plate together constitute a vibration isolation frequency band control device.

[0016] Furthermore, when the spring A is compressed, the raised structure on the inner wall of the movable baffle can contact the triangular particle damper, thereby directly transmitting the vibration to the triangular particle damper, and the spherical particle limit plate plays the role of transmitting the vibration;

[0017] Each movable baffle is provided with four limit structures on the outer wall. When the adjustment spring B is in a compressed state, it provides thrust to the movable baffle. At the same time, the limit bolt is in a fixed state, pulling the movable baffle to keep it in a balanced state. The measuring ruler is used to measure the moving distance of the adjustment spring B.

[0018] Furthermore, the movable baffle of the enclosure structure can be moved by adjusting the limit bolts and the corresponding nut structure, wherein the inward movement of the movable baffle can make the triangular particle dampers tighter; the triangular particle dampers are close to each other, and the rectangular connecting rod connecting the spherical particle dampers cannot be stretched, so that the spherical particle dampers are also tighter; the outward movement of the movable baffle can make the triangular particle dampers looser; similarly, the spherical particle dampers are looser; by adjusting the tightness between the triangular particle dampers, the vibration isolation frequency band can be controlled.

[0019] Furthermore, each of the non-local connecting devices includes a non-local connecting rod and two sliding bolts. The non-local connecting rod is a rectangular parallelepiped structure and a sliding groove is provided at the bottom of the non-local connecting rod. The bottom of the sliding bolt is fixed to the upper surface of the triangular particle damper, and the top of the sliding bolt is provided with a slider that cooperates with the sliding groove.

[0020] The heights of the sliding bolts on the tops of the triangular particle dampers between adjacent damping areas are different, while the heights of the sliding bolts on the tops of two triangular particle dampers connected by the same non-local connecting rod are consistent; the triangular particle dampers are obtained by 3D printing technology.

[0021] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0022] (1) The present invention is based on mechanical metamaterials, combined with non-local structures and particle damping structures, and has a wider low-frequency vibration isolation effect than traditional vibration isolation and noise reduction structures;

[0023] (2) The device of the present invention adopts a multi-adjustable particle damping structure, that is, an inner and outer double particle damping structure. The outer particle damping is a triangular structure, and its tightness can be adjusted by the enclosure structure. The triangular particle damping mainly uses friction to dissipate energy, and the inner part of the triangular particle damping is spherical particle damping, and the spherical particle damping mainly dissipates vibration energy through collision. This is because compared with round particles, triangular particles have a larger contact area with the base plate and have greater friction. Compared with triangular particles, round particles are easier to roll under vibration, resulting in collisions between particles. The two particles are combined in a nested manner, which can better exert their respective energy dissipation characteristics compared to mixing triangular particles and round particles together. Compared with traditional single-type particle damping, the present invention classifies and strengthens the friction energy dissipation characteristics and collision energy dissipation characteristics of particle damping, and thus has a better and wider vibration isolation frequency band.

[0024] (3) The device of the present invention can adjust the distance between the triangular particles by adjusting the position of the movable plate, and the change in the distance between the triangular particle damping will change the distance of the internal spherical particle damping; the change in the distance between the particle damping can change the vibration isolation frequency band of the vibration isolation device, thereby achieving the adjustment of the vibration isolation frequency band.

[0025] (4) The device of the present invention has a non-local connection device, a spring connection structure and a rod connection structure; wherein the spring mainly realizes the connection between the triangular particle dampers, the rod mainly realizes the connection between the spherical particle dampers inside the adjacent triangular particle dampers, and the non-local connection device mainly realizes the direct connection between the internal triangular particle dampers between different domains. These connection devices can amplify the vibration of a single point or a single surface and transmit it to the entire vibration isolation device, so that all the particle dampers in the device of the present invention generate vibration, thereby achieving more efficient vibration isolation.

[0026] (5) The device of the present invention is a purely mechanical device, does not contain electronic components, and the parts thereof are easy to process; compared with general electronic control structures, it has the advantages of low cost, good durability and no electromagnetic interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic structural diagram of a vibration isolation device provided in an embodiment of the present invention.

[0028] FIG2(a) is a schematic diagram of the front structure of the vibration isolation device provided in an embodiment of the present invention; FIG2(b) is a schematic diagram of the left structure of the vibration isolation device provided in an embodiment of the present invention; FIG2(c) is a schematic diagram of the top structure of the vibration isolation device provided in an embodiment of the present invention; FIG2(d) is a schematic diagram of the three-dimensional structure of the vibration isolation device provided in an embodiment of the present invention;

[0029] Figure 3 This is a cross-sectional structure of the first layer and an enlarged schematic diagram of the vibration isolation device provided in an embodiment of the present invention.

[0030] Figure 4 The second layer cross-sectional structure and enlarged schematic diagram of the vibration isolation device provided in an embodiment of the present invention.

[0031] Figure 5 The third layer cross-sectional structure and its enlarged schematic diagram of the vibration isolation device provided by an embodiment of the present invention.

[0032] Figure 6 A schematic diagram of the explosion structure of the vibration isolation device provided in an embodiment of the present invention;

[0033] FIG7( a ) is a schematic diagram of the exploded structure of the enclosure structure of the vibration isolation device provided in an embodiment of the present invention; FIG7( b ) is a schematic diagram of a partially enlarged structure of the enclosure structure.

[0034] Figure 8 This is a schematic diagram of the cross-sectional structure of the first layer of the vibration isolation device provided by an embodiment of the present invention.

[0035] Figure 9 This is a schematic diagram of the second-layer cross-sectional structure of the vibration isolation device provided by an embodiment of the present invention.

[0036] Figure 10This is a schematic diagram of the cross-sectional structure of the third layer of the vibration isolation device provided by an embodiment of the present invention.

[0037] Figure 11 This is a schematic cross-sectional view of a vibration isolation device provided in an embodiment of the present invention.

[0038] Figure 12 This is a schematic cross-sectional view of a vibration isolation device provided in an embodiment of the present invention.

[0039] Figure 13 A perspective view of one-sixth of the damping area of ​​the vibration isolation device provided by an embodiment of the present invention.

[0040] FIG14(a) is a schematic diagram of the front structure of the triangular particle damper in one-sixth of the damping area of ​​the vibration isolation device provided by an embodiment of the present invention; FIG14(b) is a schematic diagram of the left structure of the triangular particle damper in one-sixth of the damping area of ​​the vibration isolation device provided by an embodiment of the present invention; FIG14(c) is a schematic diagram of the top structure of the triangular particle damper in one-sixth of the damping area of ​​the vibration isolation device provided by an embodiment of the present invention; FIG14(d) is a schematic diagram of the three-dimensional structure of the triangular particle damper in one-sixth of the damping area of ​​the vibration isolation device provided by an embodiment of the present invention;

[0041] Figure 15 This is a schematic diagram of the first-layer cross-sectional structure of the triangular particle damper in one-sixth of the damping area of ​​the vibration isolation device provided by an embodiment of the present invention.

[0042] Figure 16 This is a schematic diagram of the second-layer cross-sectional structure of the triangular particle damper in one-sixth of the damping area of ​​the vibration isolation device provided by an embodiment of the present invention.

[0043] Figure 17 This is a schematic diagram of the third layer cross-sectional structure of the triangular particle damper in the one-sixth damping area of ​​the vibration isolation device provided by an embodiment of the present invention.

[0044] Figure 18 A schematic perspective structural diagram of a triangular particle damper of the vibration isolation device provided in an embodiment of the present invention.

[0045] Figure 19 This is a schematic cross-sectional structural diagram of an upper triangular particle damping unit in a triangular particle damper of a vibration isolation device provided by an embodiment of the present invention.

[0046] Figure 20 This is a schematic cross-sectional structural diagram of a middle-layer triangular particle damping unit in a triangular particle damper of a vibration isolation device provided by an embodiment of the present invention.

[0047] Figure 21 This is a schematic cross-sectional structural diagram of a lower triangular particle damping unit within a triangular particle damper of a vibration isolation device provided by an embodiment of the present invention.

[0048] FIG22( a ) is a schematic diagram of the structure of the non-local connecting devices provided in an embodiment of the present invention; FIG22( b ) and FIG22( c ) are schematic diagrams of the three-dimensional enlarged structure of the non-local connecting rod and the sliding bolt.

[0049] Figure 23 A comparison diagram of acceleration responses of a vibration isolation device provided by an embodiment of the present invention within the range of 0-300 Hz, showing a vibration isolation device with triangular particle damping and a vibration isolation device without triangular particle damping.

[0050] Figure 24 A comparison diagram of the velocity responses of a vibration isolation device provided by an embodiment of the present invention within the range of 0-300 Hz, a vibration isolation device with triangular particle damping and a vibration isolation device without triangular particle damping.

[0051] Figure 25 A comparison diagram of the deformation responses of a vibration isolation device provided by an embodiment of the present invention within the range of 0-300 Hz, with and without triangular particle damping.

[0052] Figure 26 A stress response comparison diagram of a vibration isolation device provided by an embodiment of the present invention within the range of 0-300 Hz, showing a vibration isolation device with triangular particle damping and a vibration isolation device without triangular particle damping.

[0053] Figure 27 A comparison diagram of acceleration responses of a vibration isolation device provided by an embodiment of the present invention within the range of 0-300 Hz, a vibration isolation device with spherical particle damping within a triangular particle damping structure and a vibration isolation device without spherical particle damping within a triangular particle damping structure.

[0054] Figure 28 A comparison diagram of the velocity responses of a vibration isolation device provided by an embodiment of the present invention within the range of 0-300 Hz, a vibration isolation device with spherical particle damping within a triangular particle damping structure and a vibration isolation device without spherical particle damping within a triangular particle damping structure.

[0055] Figure 29 A comparison diagram of the deformation responses of a vibration isolation device provided by an embodiment of the present invention within the range of 0-300 Hz, a vibration isolation device with spherical particle damping within a triangular particle damping structure and a vibration isolation device without spherical particle damping within a triangular particle damping structure.

[0056] Figure 30 A stress response comparison diagram of a vibration isolation device provided by an embodiment of the present invention within the range of 0-300 Hz, a vibration isolation device with spherical particle damping within a triangular particle damping structure and a vibration isolation device without spherical particle damping within a triangular particle damping structure.

[0057] Figure markings: 1-base plate, 2-partition structure, 3-damping area, 4-enclosing structure, 5-non-local connecting device, 6-nut No. 1, 7-fixed baffle, 8-adjusting spring B, 9-measuring ruler, 10-limiting bolt, 11-nut No. 2, 12-fixing bolt No. 1, 13-nut No. 3, 14-fixing gasket, 15-fixing bolt No. 2, 16-movable baffle, 17-adjusting spring A, 18-spherical particle limiting plate, 19-spring, 20-rectangular connecting rod, 21-spherical particle damping, 22-triangular particle damping, 23-spring, 24-rectangular connecting rod, 25-sliding bolt, 26-non-local connecting rod. DETAILED DESCRIPTION

[0058] The following is a detailed description of embodiments of the present invention. Examples of these embodiments are shown in the accompanying drawings, in which the same or similar reference numerals are used to represent the same or similar elements, or elements having the same or similar functions. These examples are provided for illustrative purposes only and should not be construed as limiting the present invention.

[0059] By adjusting the connection spring stiffness, particle damping density, particle damping geometry, and the number of triangular particle damping layers, the width and position of the elastic wave band gap can be controlled. This embodiment provides a non-local, multi-adjustable particle damping, wide-band, low-frequency vibration reduction metamaterial device. By specifically enhancing the frictional energy dissipation and vibration energy dissipation characteristics of the particle damping, it can achieve wide-band, low-frequency vibration isolation on a two-dimensional plane.

[0060] The solution adopted by the non-local multi-adjustable particle damping wide low-frequency vibration reduction metamaterial device of the embodiment of the present invention is to connect the device domain requiring low-frequency vibration isolation to the fixed outer baffle in the embodiment of the present invention. Vibration waves on the two-dimensional plane are transmitted to the peripheral triangular particle dampers through the enclosure structure. The triangular particle dampers begin to vibrate and generate relative motion with the base plate, thereby dissipating vibration energy through friction. The vibration of the triangular particle dampers drives the vibration of the spherical particle dampers within them, and the spherical particles constantly collide and dissipate vibration energy. At the same time, the vibration of the triangular particle dampers at the edge is transmitted to the triangular particle dampers at the center of the damping area through springs and connecting rods. The triangular particle dampers at the center then transmit the vibration to the triangular particle dampers in other damping areas through the non-local connection device, achieving an overall vibration isolation effect. At the same time, due to the influence of the bandgap characteristics of the periodic structure, it has a better vibration isolation effect for specific frequency bands.

[0061] The non-local multiple adjustable particle damping wide low frequency vibration reduction metamaterial device of the embodiment of the present invention is as follows Figures 1 to 6As shown, the structure mainly includes a base plate 1, a partition structure 2, a damping area 3, an enclosure structure 4, and a non-local connection device 5. The base plate 1 and the partition structure 2 are welded to form six damping areas 3. In this embodiment, each damping area 3 includes four triangular particle dampers 22; each triangular particle damper 22 includes an upper triangular particle damping unit, a middle triangular particle damping unit, and a lower triangular particle damping unit, and each layer of particle damping unit is provided with a spherical particle damper 21. The enclosure structure 4 and the damping area 3 are in contact with each other, so that the movement of the particle damper is fixed to a fixed area. In this embodiment, the triangular particle damper at the center of each damping area is connected by the non-local connection device 5, so that the vibration can be transmitted to all damping areas, and the vibration energy can be dissipated more thoroughly. Figures 8 to 10 is a cross-sectional view of an embodiment of the present invention, showing the positions and distribution of the first layer of granular balls, the second layer of granular balls, and the third layer of granular balls respectively; Figure 11 and Figure 12 They are respectively vertical cross-sectional views of the embodiments of the present invention in different directions;

[0062] FIG7 is an exploded schematic diagram of the enclosure structure provided by an embodiment of the present invention. The enclosure structure 4 mainly includes a No. 1 nut 6, a fixed baffle 7, an adjusting spring A8, a measuring ruler 9, a limit bolt 10, a No. 2 nut 11, a No. 1 fixing bolt 12, a No. 3 nut 13, a fixing washer 14, a No. 2 fixing bolt 15, a movable baffle 16, an adjusting spring B17, and a spherical particle limit plate 18. The fixed baffle 7 is welded to the bottom plate 1, and the movable baffle 16 is connected to the fixed baffle 7 via the limit bolt 10 and the adjusting spring A8. The adjusting spring A8 is in a compressed state, one end of the limiting bolt 10 is connected to the limiting structure protruding on the movable baffle 16, and the other end is connected to the fixed baffle 7 through the No. 1 nut 6; the measuring ruler 9 is connected to the movable baffle 16 through five parts, namely the No. 2 nut 11, the No. 1 fixing bolt 12, the No. 3 nut 13, the fixing gasket 14, and the No. 2 fixing bolt 15, to measure the moving position of the movable baffle 16; the two ends of the adjusting spring B17 are respectively welded to the movable baffle 16 and the spherical particle limiting plate 18.

[0063] Specifically, the spherical particle limiting plate 18 is arranged inside the upper triangular particle damping unit and the lower triangular particle damping unit close to the enclosure structure. The outer wall of the spherical particle limiting plate 18 is connected to the movable baffle 16 through the adjusting spring A17. The inner wall of the movable baffle 16 is provided with a convex structure, and the outer wall is provided with a protruding limiting structure. The fixing gasket 14 is installed on the limiting structure through the No. 2 nut 11 and the No. 1 fixing bolt 12. The fixing gasket 14 is fixed with a measuring ruler 9 through the No. 3 nut 13 and the No. 2 fixing bolt 15. The adjusting spring B8 is sleeved in the limiting bolt 10. One end of the adjusting spring B8 contacts the fixed baffle 7, and the other end contacts the limiting structure; the end of the limiting bolt 10 passes through the bolt hole on the fixed baffle 7 and is fixed by the No. 1 nut 6, and the fixed baffle 7 is fixed to the outermost side of the base plate 1; the movable baffle, the limiting bolt, the adjusting spring A, the adjusting spring B, the measuring ruler and the spherical particle limiting plate together constitute a vibration isolation frequency band control device.

[0064] Figure 13 Figure 14 shows the particle damping structure of a damping region of a device according to an embodiment of the present invention. In this embodiment, each damping region has four triangular particle dampers. The triangular particle dampers between different damping regions are primarily connected by springs 19 to transmit vibration waves between the different damping regions. The spherical particle dampers between different damping regions are primarily connected by rectangular connecting rods 20 to transmit vibrations. Figure 18 A perspective view of a triangular particle damper 22 located at the center of a damping region. The triangular particle dampers in the same damping region are connected by springs 23, and the spherical particle dampers are connected by rectangular connecting rods 24. Figures 15 to 18 The cross-sectional view of the triangular particle damping in a domain. The triangular particle damping is divided into upper triangular particle damping units, middle triangular particle damping units and lower triangular particle damping units. The upper triangular particle damping units and the lower triangular particle damping units are of the same size, while the middle triangular particle damping units are smaller in structure. Each layer of triangular particle damping units is hollowed out, and the hollowed-out areas are spherical particle damping units 21. Figures 19 to 21 It is a cross-sectional view of a triangular particle damper located at the center of a damping area; FIG22 is a schematic structural diagram of the non-local connecting rod device, which is welded to the top of the triangular particle damper using a sliding bolt 25. A sliding groove is provided in the middle of the bottom of the non-local connecting rod 26, and the slider on the top of the sliding bolt 25 can move in the sliding groove.

[0065] The working principle of the non-local multi-adjustable particle damping wide low-frequency vibration reduction metamaterial device of the above-mentioned invention embodiment includes:

[0066] The principle of nonlocal structure in mechanics mainly involves taking into account nonlocal effects when describing the mechanical behavior of an object or system, that is, the mechanical state of a point is not only determined by the local situation at that point, but is also affected by the state of other points. Traditional continuum mechanics theory assumes that the mechanical state (such as stress and strain) of an object or material at each point depends only on the local properties of that point. However, in many practical situations, this assumption is not sufficient, especially when dealing with nanoscale materials, soft matter, biomaterials, complex composite materials and heterogeneous materials. The principle of nonlocal structure in mechanics provides a more accurate and comprehensive description of mechanical behavior by considering the long-range interactions between different damping regions within the material. This is of great significance for understanding and designing complex materials and systems.

[0067] Mechanical metamaterials are special artificial structural materials that can create band gaps by designing specific periodic structures or local resonant units, allowing vibration energy to be absorbed and scattered within the material, reducing the transmission of vibration energy. For example, embedding high-damping materials or designing complex geometric structures can increase the path of vibration waves within the material, increasing energy loss, thereby reducing vibration transmission and achieving vibration isolation.

[0068] Particle damping, a technology that uses granular media to absorb and dissipate mechanical vibration energy, offers unique advantages in mechanical vibration isolation. The fundamental principle of particle damping is to dissipate vibration energy by converting it into heat through collisions, friction, and intermolecular interactions between particles. Whenever vibration is transmitted into a granular medium, the relative motion and friction between the particles generate internal friction, leading to a gradual attenuation of energy. Collisions between particles consume significant amounts of kinetic energy, particularly at high frequencies, where frequent collisions significantly increase energy dissipation efficiency. Sliding and rolling friction between particles are also significant sources of energy dissipation. Friction converts vibration energy into heat. Particle damping exhibits significant nonlinear characteristics, adapting to variations in vibration frequency and amplitude. Unlike traditional linear damping materials, the relationship between the damping force and vibration amplitude and frequency is more complex, resulting in excellent vibration isolation across a wide frequency range.

[0069] Figures 23 to 26Comparison of simulation calculation results of the vibration isolation device provided in an embodiment of the present invention in the 100-800 Hz frequency band with and without particle damping; respectively, comparison diagrams of the simulation calculation results of acceleration, velocity, displacement and stress in the 100-800 Hz frequency band; its boundary condition is that acceleration excitation is applied to a moving baffle at one-sixth of the boundary of the device, and the rest of the structure is free; the solid line in the figure is the simulation calculation result when there is no particle damping, and the dotted line is the simulation calculation result when there is particle damping; it can be seen that at the characteristic frequency, the simulation calculation result with triangular particle damping is significantly greater than the calculation result without particle damping; therefore, the simulation calculation results show that adding triangular particle damping has the effect of vibration isolation and vibration reduction.

[0070] Figures 27 to 30 Simulation results for the vibration isolation device provided by the present invention, with and without triangular particle damping, are compared. Response analysis was performed for four parameters: acceleration, velocity, displacement, and stress. The calculated boundary was adjusted to apply acceleration excitation to a moving baffle at one-sixth of the boundary, with the remaining structure free. The solid line in the figure shows the simulation result without spherical particle damping, while the dashed line shows the simulation result with spherical particle damping. It can be seen that at the characteristic frequency, the simulation result with spherical particle damping is significantly greater than the result without spherical particle damping. Therefore, the simulation results show that adding spherical particle damping has a vibration isolation and reduction effect.

[0071] To sum up, compared with the previous particle damping vibration isolation devices, the device of the embodiment of the present invention designs a wide low-frequency vibration isolation and vibration reduction device in which a non-local connection device and a multiple particle damping structure work together. On the basis of the particle damping structure, the design concept of the periodic metamaterial structure is incorporated, and the friction and collision effects of the particle damping are fully utilized to dissipate the collision energy with maximum efficiency. The device can be used not only for vibration isolation and vibration reduction in a two-dimensional specific frequency band, but also for vibration isolation and vibration reduction in a wide frequency range. Based on this working condition, a nonlinear vibration isolation and noise reduction device is provided, which is easy to manufacture, has significant effects, is simple to operate, has no electromagnetic infection, and has a wide frequency range vibration isolation effect.

[0072] The device of this embodiment is a two-dimensional structure, and only six damping regions are designed in the two-dimensional plane. Each damping region only provides four triangular particle dampers. The number of triangular particle dampers in each damping region can be greater, and the number of layers of triangular particle dampers can be greater.

[0073] The device and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of these modules may be selected based on actual needs to achieve the objectives of the present embodiments. Persons of ordinary skill in the art will be able to understand and implement the present embodiments without inventive effort.

[0074] It will be understood by those skilled in the art that, unless expressly stated otherwise, the singular forms "a", "an", "said" and "the" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the description of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, "connected" or "coupled" as used herein may include wireless connections or couplings. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items.

[0075] The present invention is not limited to the embodiments described above. The above description of the specific embodiments is intended to describe and illustrate the technical solutions of the present invention. The above specific embodiments are merely illustrative and not restrictive. Without departing from the scope of the present invention and the scope of protection of the claims, those skilled in the art may make various specific modifications based on the teachings of the present invention, all of which fall within the scope of protection of the present invention.

Claims

1. A non-local multi-adjustable particle damping wide low-frequency vibration reduction metamaterial device, characterized in that: It includes a base plate, a triangular particle damper, a spherical particle damper, an enclosure structure and a non-local connection device; the base plate is a regular hexagonal structure, and a partition structure is fixed on the base plate, and the partition structure is installed along the diagonal of the hexagon and divides the metamaterial device into six damping areas; each damping area includes more than four triangular particle dampers, and each triangular particle damper includes an upper triangular particle damping unit, a middle triangular particle damping unit and a lower triangular particle damping unit, and each layer of particle damping unit is provided with a spherical particle damper; an enclosure structure is provided on the outside of each damping area, and a vibration isolation frequency band control device is provided in the enclosure structure, and a vibration transmission device is provided between each damping area, between the triangular particle dampers in each damping area, between the spherical particle dampers in each damping area, and between each enclosure structure and the corresponding damping area; the vibration transmission device includes a spring and a rectangular connecting rod; The non-local connection device is used to connect the triangular particle dampers in two damping areas separated by one damping area, and there is no vibration transmission device directly connected between each triangular particle damper and the adjacent damping area.

2. The non-local multi-adjustable particle damping wide low-frequency vibration reduction metamaterial device according to claim 1, characterized in that: The upper triangular particle damping unit and the lower triangular particle damping unit are larger than the middle triangular particle damping unit. Each triangular particle damping unit is provided with a cavity for placing the spherical particle damper.

3. The non-local multi-adjustable particle damping wide low-frequency vibration reduction metamaterial device according to claim 1 or 2, characterized in that: The walls of the upper triangular particle damping unit and the lower triangular particle damping unit are both provided with rectangular openings; the height of the rectangular openings is smaller than the diameter of each spherical particle of the spherical particle damping; The middle-layer triangular particle damping units in the same damping area are connected to each other through springs, and three springs are used between the walls of two opposite middle-layer triangular particle damping units; The lower triangular particle damping units in different damping areas are connected to each other through springs; The spherical damping particles in all adjacent upper triangular particle damping units in different damping areas and the same damping area are connected by rectangular connecting rods.

4. The non-local multi-adjustable particle damping wide low-frequency vibration reduction metamaterial device according to claim 1, characterized in that: The bottom surfaces of the cavities of the upper, middle and lower triangular particle damping units are set as inclined surfaces. When the spherical particle dampers are stationary inside the triangular particle damping units of each layer, they can move closer to each other to ensure that the spherical particle dampers fully collide with each other during vibration.

5. The non-local multi-adjustable particle damping wide low-frequency vibration reduction metamaterial device according to claim 1, characterized in that: The triangular particle damper is placed horizontally on the bottom plate. The upper surface of the bottom plate and the lower surface of the triangular particle damper are designed to be relatively rough so as to provide friction between each other during vibration and consume vibration energy.

6. The non-local multi-adjustable particle damping wide low-frequency vibration reduction metamaterial device according to claim 1, characterized in that: The enclosure structure includes a fixed baffle, a limiting bolt, a movable baffle, an adjusting spring A, an adjusting spring B, a measuring ruler and a spherical particle limiting plate. The spherical particle limiting plate is arranged inside the upper triangular particle damping unit and the lower triangular particle damping unit close to the enclosure structure. The outer wall of the spherical particle limiting plate is connected to the movable baffle through the adjusting spring A. The inner wall of the movable baffle is provided with a protruding structure, and the outer wall is provided with a limiting structure. A fixed gasket and a limiting bolt are provided on the limiting structure, and a measuring ruler is fixed through the fixed gasket. The limiting bolt is sleeved with an adjusting spring B, one end of the adjusting spring B contacts the fixed baffle, and the other end contacts the limiting structure; the end of the limiting bolt passes through the bolt hole on the fixed baffle and is fixed by a nut, and the fixed baffle is fixed to the outermost side of the base plate; the movable baffle, limiting bolt, adjusting spring A, adjusting spring B, measuring ruler and spherical particle limiting plate together constitute a vibration isolation frequency band control device.

7. The non-local multi-adjustable particle damping wide low-frequency vibration reduction metamaterial device according to claim 6, characterized in that: When the regulating spring A is compressed, the convex structure on the inner wall of the movable baffle can contact the triangular particle damper, thereby directly transmitting the vibration to the triangular particle damper, and the spherical particle limit plate plays the role of transmitting the vibration; Each movable baffle is provided with four limit structures on the outer wall. When the adjustment spring B is in a compressed state, it provides thrust to the movable baffle. At the same time, the limit bolt is in a fixed state, pulling the movable baffle to keep it in a balanced state. The measuring ruler is used to measure the moving distance of the adjustment spring B.

8. The non-local multi-adjustable particle damping wide low-frequency vibration reduction metamaterial device according to claim 6, characterized in that: The movable baffle of the enclosure structure can be moved by adjusting the limit bolts and the corresponding nut structure, wherein the inward movement of the movable baffle can make the triangular particle dampers closer together; the triangular particle dampers are close to each other, and the rectangular connecting rod connecting the spherical particle dampers cannot be stretched, so that the spherical particle dampers are also closer together; the outward movement of the movable baffle can make the triangular particle dampers looser; similarly, the spherical particle dampers are looser; by adjusting the tightness between the triangular particle dampers, the vibration isolation frequency band can be controlled.

9. The non-local multi-adjustable particle damping wide low-frequency vibration reduction metamaterial device according to claim 1, characterized in that: Each of the non-local connecting devices includes a non-local connecting rod and two sliding bolts. The non-local connecting rod is a rectangular parallelepiped structure and a sliding groove is provided at the bottom of the non-local connecting rod. The bottom of the sliding bolt is fixed to the upper surface of the triangular particle damper, and the top of the sliding bolt is provided with a slider that cooperates with the sliding groove.

10. The non-local multi-adjustable particle damping wide low-frequency vibration reduction metamaterial device according to claim 9, characterized in that: The heights of the sliding bolts on the tops of the triangular particle dampers between adjacent damping areas are different, while the heights of the sliding bolts on the tops of two triangular particle dampers connected by the same non-local connecting rod are consistent; the triangular particle dampers are obtained by 3D printing technology.

Images