A one-dimensional adjustable stiffness metamaterial vibration isolation unit and vibration isolation device

Abstract

The present invention discloses a one-dimensional adjustable stiffness metamaterial vibration isolation unit and vibration isolation device. The vibration isolation unit includes an upper panel, a lower panel, and a spring curved beam. The spring curved beam includes an upper arc-shaped hard beam section, a middle elastic section, and a lower arc-shaped hard beam section. The upper end of the middle elastic section is fixedly connected to the upper arc-shaped hard beam section, and the lower end is connected to the lower arc-shaped hard beam section. The center of the middle elastic section overlaps with the arc centers of the upper and lower arc-shaped hard beam sections. The upper arc-shaped hard beam section is connected to the lower surface of the upper panel, and the upper arc-shaped hard beam section and the upper panel can switch between fixed and sliding fits. The lower arc-shaped hard beam section is connected to the upper surface of the lower panel, and the lower arc-shaped hard beam section and the lower panel can switch between fixed and sliding fits. The present invention achieves continuity and smoothness in the change of metamaterial stiffness by adjusting the effective support stiffness of the spring curved beam, effectively achieving a wide range of stiffness changes, and adapting to the requirements of structural stiffness under different working conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of sound absorption and noise reduction, and in particular relates to a one-dimensional adjustable stiffness metamaterial vibration isolation unit and a vibration isolation device. Background Art

[0002] Vibration problems are closely related to human daily life and scientific and technological development. Vibration not only interferes with human life and affects human health, but also causes buildings, mechanical equipment and precision instruments to malfunction or even be damaged. In the fields of aerospace, automotive engineering, shipbuilding, large structures and precision instrument processing, people use the deformation of elastic elements to form effective vibration isolation to improve the safety, stability, controllability and comfort of personnel and equipment. The large-scale and complex development of modern structures has posed new challenges to the vibration isolation effect of structures. However, the design optimization method based on linear theory has an irreconcilable contradiction in analysis and application, that is, if the vibration isolation frequency band is to be widened, the stiffness of the vibration isolation structure must be reduced, which will inevitably lead to a decrease in the bearing capacity of the structure. In response to the contradictory relationship between bearing and vibration isolation, many researchers have proposed a quasi-zero stiffness passive vibration isolation method and an adjustable stiffness active vibration isolation method.

[0003] The invention patent application, with application number "CN217301390U" and titled "One-dimensional quasi-zero stiffness metamaterial nonlinear vibration isolation device based on elastic material," discloses a one-dimensional quasi-zero stiffness metamaterial composed of a single-cell array. To address the problems of large assembly errors, poor reliability, and high friction caused by the parallel connection of positive and negative stiffness elements in most quasi-zero stiffness vibration isolation systems, this patent utilizes the structure of the elastic element itself to achieve parallel connection of positive and negative stiffness, improving overall reliability, reducing manufacturing costs, and effectively achieving low-frequency vibration isolation. While this patent proposes a quasi-zero stiffness metamaterial with excellent vibration isolation, its ability to cope with forces in different environments is limited. When the force exceeds the quasi-zero stiffness equilibrium position, the invention cannot achieve its low-frequency vibration isolation effect.

[0004] The invention patent application with application number "CN117145936A" and name "An aluminum alloy adjustable stiffness mechanical superstructure" discloses a gear set superstructure with active stiffness control; it includes an outer ring gear, an outer planetary gear, inner and outer planetary gears, and a special-shaped sun gear. During operation, smooth control of stiffness can be achieved by manipulating the control hand steering and control gears, which solves the defects of existing adjustable stiffness devices such as difficulty in adjustment and small adjustment range. However, because it uses a gear meshing device, it has high strength requirements for parts and cannot achieve effective vibration isolation of the structure in lower frequency bands. In addition, there are too many additional equipment, which increases the overall size and weight of the structure. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the above-mentioned existing deficiencies and provide a one-dimensional adjustable stiffness metamaterial vibration isolation unit and vibration isolation device. The present invention has continuous stiffness variation and a wide range of variation, which can effectively resolve the conflicting relationship between load bearing and vibration isolation in different environments.

[0006] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0007] The invention relates to a one-dimensional adjustable stiffness metamaterial vibration isolation unit, comprising an upper panel, a lower panel and at least one spring curved beam arranged between the upper panel and the lower panel, the spring curved beam comprising an upper arc-shaped hard beam section, a middle elastic section and a lower arc-shaped hard beam section, the upper end of the middle elastic section is fixedly connected to the upper arc-shaped hard beam section, the lower end is connected to the lower arc-shaped hard beam section, and the center of the middle elastic section overlaps with the arc centers of the upper arc-shaped hard beam section and the lower arc-shaped hard beam section, the upper arc-shaped hard beam section is connected to the lower surface of the upper panel, the upper arc-shaped hard beam section and the upper panel can switch between fixed cooperation and sliding cooperation, the lower arc-shaped hard beam section is connected to the upper surface of the lower panel, the lower arc-shaped hard beam section and the lower panel can switch between fixed cooperation and sliding cooperation, when the upper arc-shaped hard beam section slides relative to the upper panel and the lower arc-shaped hard beam section slides relative to the lower panel, the inclination angle of the middle elastic section and the horizontal plane changes, and a connecting hole is provided at the center of the middle elastic section.

[0008] To optimize the above technical solutions, specific measures taken also include:

[0009] The upper end of the middle elastic section is fixedly connected to the left end of the upper arc-shaped hard beam section, and the lower end of the middle elastic section is fixedly connected to the right end of the lower arc-shaped hard beam section, so that the spring curved beam has an S-shaped structure.

[0010] An upper slide is provided on the lower surface of the upper panel, and an upper slide groove running left and right is provided on the upper arc-shaped hard beam section. The upper slide is stuck in the upper slide groove and slides with the upper slide groove. A lower slide is provided on the upper surface of the lower panel, and a lower slide groove running left and right is provided on the lower arc-shaped hard beam section. The lower slide is stuck in the lower slide groove and slides with the lower slide groove.

[0011] The right end of the upper chute opens at the right end of the upper arc-shaped hard beam section, and the right end of the upper chute is detachably covered with an upper plug, which is used to seal the right end of the upper chute. The left end of the lower chute opens at the left end of the lower arc-shaped hard beam section, and the left end of the lower chute is detachably covered with a lower plug, which is used to seal the left end of the lower chute.

[0012] The lower surface of the upper panel is provided with an upper curved plate that is adapted to the shape of the upper surface of the upper curved hard beam section, the upper slide is fixed on the lower surface of the upper curved plate, the upper surface of the lower panel is provided with a lower curved plate that is adapted to the shape of the lower surface of the lower curved hard beam section, the lower slide is fixed on the upper surface of the lower curved plate, when the upper curved hard beam section is fixedly matched with the upper panel, the upper curved plate conflicts with the upper curved hard beam section, when the lower curved hard beam section is fixedly matched with the lower panel, the lower curved plate conflicts with the lower curved hard beam section.

[0013] The stiffness of the upper arc-shaped hard beam section and the lower arc-shaped hard beam section is greater than that of the middle elastic section, and the stiffness of the upper panel and the lower panel is not less than that of the upper arc-shaped hard beam section and the lower arc-shaped hard beam section.

[0014] The upper panel, lower panel and spring curved beam are all manufactured by 3D printing.

[0015] There are multiple spring curved beams, and the arrangement requirement of the spring curved beams between the upper panel and the lower panel is that the connection holes of the spring curved beams are coaxial.

[0016] The upper panel and the lower panel have the same structure, and the upper arc-shaped hard beam section and the lower arc-shaped hard beam section have the same structure.

[0017] The one-dimensional adjustable stiffness metamaterial vibration isolation device is composed of multiple one-dimensional adjustable stiffness metamaterial vibration isolation units stacked and positioned in sequence. The stacking method is: the upper panel or lower panel of the one-dimensional adjustable stiffness metamaterial vibration isolation unit is fixed to the lower panel or upper panel of the adjacent one-dimensional adjustable stiffness metamaterial vibration isolation unit.

[0018] The beneficial effects of the present invention are:

[0019] (1) The one-dimensional adjustable stiffness metamaterial vibration isolation unit of the present invention comprises an upper panel, a lower panel and a spring curved beam. The spring curved beam can change the angle between the middle elastic section and the horizontal plane by rotating. When the angle between the middle elastic section and the horizontal plane is large, the support stiffness of the vibration isolation unit is low. When the angle between the middle elastic section and the horizontal plane is small, the support stiffness of the vibration isolation unit is high. By adjusting the effective support stiffness of the S-shaped spring curved beam, the continuity and smoothness of the metamaterial stiffness change are achieved, and a wide range of stiffness changes are effectively achieved, which can adapt to the requirements of structural stiffness under different working conditions.

[0020] (2) The present invention utilizes the elastic deformation of the curved beam and has excellent vibration isolation characteristics in a specific working frequency band, effectively reducing structural damage caused by external environmental vibrations. It can be applied to vibration isolation in aerospace, ships, satellites, and other fields.

[0021] (3) The present invention adopts 3D printing technology for processing and assembly, which facilitates the design of parts and has high flexibility and adjustability.

[0022] (4) Since the present invention uses a small number of components, has a simple structure, and is easy to process, it has a short manufacturing cycle and significant design effects, and has certain practical engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an assembly diagram of the one-dimensional adjustable stiffness metamaterial vibration isolation unit of the present invention, wherein the left side is a structural exploded view, and the right side is an exploded view in the main view state;

[0024] Figure 2 Schematic diagram of different stiffness states of the one-dimensional adjustable stiffness metamaterial vibration isolation unit of the present invention, wherein the upper left is the overall structure diagram, the upper right is the state diagram of the one-dimensional adjustable stiffness metamaterial vibration isolation unit when the structural stiffness is minimum; the lower left is the intermediate state diagram during the stiffness adjustment process; the lower right is the state diagram of the one-dimensional adjustable stiffness metamaterial vibration isolation unit when the structural stiffness is maximum;

[0025] Figure 3 Schematic diagram of the upper panel, wherein the upper left is a three-dimensional view of the upper panel, the upper right is a bottom view of the upper panel; the lower left is a left and right view of the upper panel; the lower right is a front and back view of the upper panel;

[0026] Figure 4 Schematic diagram of a spring curved beam, wherein the upper left is a stereoscopic view of the spring curved beam; the upper right is a front view of the spring curved beam; the lower left is a right view of the spring curved beam; and the lower right is a top view of the spring curved beam;

[0027] Figure 5 Schematic diagram of a one-dimensional tunable stiffness metamaterial vibration isolation device.

[0028] The marks in the accompanying drawings mean: upper panel 1, upper slide seat 11, upper arc plate 12, spring curved beam 2, upper arc-shaped hard beam section 21, upper slide groove 21a, upper plug 21b, middle elastic section 22, lower arc-shaped hard beam section 23, lower slide groove 23a, lower plug 23b, connecting hole 24, lower panel 3, lower slide seat 31, and lower arc plate 32. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is described and illustrated below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely used to explain this application and are not intended to limit this application. Based on the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without making any creative efforts are within the scope of protection of this application.

[0030] Obviously, the drawings described below are merely examples or embodiments of the present application. Those skilled in the art can, without inventive effort, apply the present application to other similar scenarios based on these drawings. Furthermore, it is also understood that, although the effort involved in such a development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, changes in design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as an insufficiency of the content disclosed in this application.

[0031] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it refer to independent or alternative embodiments that are mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments unless there is a conflict.

[0032] Unless otherwise defined, the technical or scientific terms used in this application should have the ordinary meaning understood by a person of ordinary skill in the technical field to which this application belongs. The words "a", "an", "a", "the" and the like used in this application do not indicate a limit on quantity and may indicate the singular or plural. The terms "include", "comprise", "have" and any variations thereof used in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or units (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units that are inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The words "multiple" / "several" used in this application refer to two or more. "And / or" describes the association relationship between associated objects, indicating that three relationships can exist. For example, "A and / or B" can mean: A exists alone, A and B exist at the same time, or B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific order for the objects.

[0033] like Figure 1-4 The one-dimensional adjustable stiffness metamaterial vibration isolation unit of the present invention comprises an upper panel 1, an S-shaped spring curved beam 2 and a lower panel 3.

[0034] The upper panel 1 includes an upper slide 11 and an upper curved plate 12. The upper curved plate 12 is fixed to the lower surface of the upper panel 1, and the upper slide 11 is fixed to the lower surface of the upper curved plate 12. Figure 3 As shown,

[0035] The spring curved beam 2 comprises an upper arc-shaped hard beam section 21, a middle elastic section 22 and a lower arc-shaped hard beam section 23. Figure 1 As shown, the upper end of the middle elastic section 22 is fixedly connected to the left end of the upper arc-shaped hard beam section 21, and the lower end of the middle elastic section 22 is fixedly connected to the right end of the lower arc-shaped hard beam section 23. The spring curved beam 2 has an S-shaped structure as a whole. An upper slide groove 21a and an upper plug 21b are provided on the upper arc-shaped hard beam section 21. The upper slide groove 21a runs left and right. The upper slide seat 11 is stuck in the upper slide groove 21a and slides with the upper slide groove 21a. The right end of the upper slide groove 21a opens at the right end of the upper arc-shaped hard beam section 21. The upper plug 21b blocks the right end of the upper slide groove 21a. The lower arc-shaped hard beam section 23 includes a lower groove 23a and a lower plug 23b. The lower groove 23a runs left and right. The lower seat 31 is stuck in the lower groove 23a and slides with the lower groove 23a. The left end of the lower groove 23a opens at the left end of the lower arc-shaped hard beam section 23, and the plug 23b blocks the left end of the lower groove 23a.

[0036] The lower panel 3 includes a lower sliding seat 31 and a lower arc-shaped plate 32 fixed on the upper surface of the lower panel 3 , and the lower sliding seat 31 is fixed on the upper surface of the lower arc-shaped plate 32 .

[0037] The S-shaped spring curved beam 2 is a nearly circular structure. The middle elastic section 22 divides the S-shaped spring curved beam 2 into two parts, each of which is an incomplete arc. The connecting hole 24 is located in the middle of the middle elastic section 22 and is used to connect the output rod of the external active mechanism.

[0038] In this embodiment, a one-dimensional adjustable stiffness metamaterial vibration isolation unit has two spring curved beams 2, which are installed antisymmetrically to ensure that the overall structure does not undergo horizontal deviation when subjected to force.

[0039] During adjustment, insert the output rod of the external active mechanism into the connecting hole 24, and adjust the two S-shaped spring curved beams 2 in opposite directions. Figure 2 In the lower right state, the angle between the middle elastic section 22 and the horizontal plane is the largest, the effective support length of the curved beam is the largest, and the bending stiffness is the smallest; when the spring curved beam 2 rotates to Figure 2 In the upper right state, the angle between the middle elastic section 22 and the horizontal plane is the smallest, the effective support length of the curved beam is the smallest, and the bending rigidity is the largest.

[0040] When conducting structural design, the overall dimensions of the complete one-dimensional adjustable stiffness metamaterial vibration isolation unit are first determined, and the relative positions of the upper slide 11, upper arc plate 12, lower slide 31, and lower arc plate 32 are determined. Secondly, the dimensions and shape of the S-shaped spring curved beam 2 are designed, including the diameter, thickness, and width of the curved beam. The dimensions of the upper and lower slide grooves are determined based on the diameter and thickness of the S-shaped spring curved beam 2, and a certain matching gap is left at the position where the slide and the slide groove match to ensure smooth installation and adjustment.

[0041] When designing a one-dimensional tunable stiffness metamaterial vibration isolation unit and vibration isolation device, follow these steps:

[0042] S1, based on the designed adjustable stiffness metamaterial, considering the reliable connection between the upper and lower panels and the S-shaped spring curved beam and ensuring that they can slide flexibly, decided to use 3D printing technology to process and manufacture each component, and polish the surface to keep it smooth.

[0043] S2, adjust the contact point between the S-shaped spring curved beam and the panel, change the effective support length of the S-shaped spring curved beam, and determine the longitudinal stiffness of the structure under different states.

[0044] S3, based on the metamaterials in different stiffness states, n (n ≥ 1) identical one-dimensional adjustable stiffness metamaterial vibration isolation units are sequentially connected to form a vibration isolation device, and the vibration isolation effect under acceleration excitation is tested.

[0045] This design dissipates vibration energy through the elastic deformation of the S-shaped spring curved beam, achieving a structure with large deformation and adjustability, which can be used for low-frequency vibration isolation in aerospace, ships, satellites, etc.

[0046] It should be noted that the stiffness of the one-dimensional adjustable stiffness metamaterial vibration isolation unit and vibration isolation device proposed in the present invention can be customized according to the specific environment by modifying the material and geometric shape, including the diameter, width and thickness of the S-shaped spring curved beam. These changes are all within the scope of protection of the present invention.

Claims

1. A one-dimensional adjustable stiffness metamaterial vibration isolation unit, characterized by: The invention comprises an upper panel (1), a lower panel (3) and at least one spring curved beam (2) arranged between the upper panel (1) and the lower panel (3); the spring curved beam (2) comprises an upper arc-shaped hard beam section (21), a middle elastic section (22) and a lower arc-shaped hard beam section (23); the upper end of the middle elastic section (22) is fixedly connected to the upper arc-shaped hard beam section (21), and the lower end is connected to the lower arc-shaped hard beam section (23); the center of the middle elastic section (22) overlaps with the arc centers of the upper arc-shaped hard beam section (21) and the lower arc-shaped hard beam section (23); the upper arc-shaped hard beam section (21) is connected to the lower surface of the upper panel (1); and the upper arc-shaped hard beam section (21) and the upper panel (1) can switch between fixed fit and sliding fit. The lower arc-shaped hard beam section (23) is connected to the upper surface of the lower panel (3), and the lower arc-shaped hard beam section (23) and the lower panel (3) can switch between fixed cooperation and sliding cooperation. When the upper arc-shaped hard beam section (21) slides relative to the upper panel (1) and the lower arc-shaped hard beam section (23) slides relative to the lower panel (3), the inclination angle of the middle elastic section (22) and the horizontal plane changes. A connecting hole (24) is provided at the center of the middle elastic section (22). The upper end of the middle elastic section (22) is fixedly connected to the left end of the upper arc-shaped hard beam section (21), and the lower end of the middle elastic section (22) is fixedly connected to the right end of the lower arc-shaped hard beam section (23), so that the spring curved beam (2) has an S-shaped structure.

2. The one-dimensional adjustable stiffness metamaterial vibration isolation unit according to claim 1, characterized in that: The lower surface of the upper panel (1) is provided with an upper slide seat (11), and the upper arc-shaped hard beam section (21) is provided with an upper slide groove (21a) running left and right. The upper slide seat (11) is stuck in the upper slide groove (21a) and slides with the upper slide groove (21a). The upper surface of the lower panel (3) is provided with a lower slide seat (31), and the lower arc-shaped hard beam section (23) is provided with a lower slide groove (23a) running left and right. The lower slide seat (31) is stuck in the lower slide groove (23a) and slides with the lower slide groove (23a).

3. The one-dimensional adjustable stiffness metamaterial vibration isolation unit according to claim 2, characterized in that: The right end of the upper slide groove (21a) opens to the right end of the upper arc-shaped hard beam section (21), and the right end of the upper slide groove (21a) is detachably covered with an upper plug (21b), and the upper plug (21b) is used to block the right end of the upper slide groove (21a). The left end of the lower slide groove (23a) opens to the left end of the lower arc-shaped hard beam section (23), and the left end of the lower slide groove (23a) is detachably covered with a lower plug (23b), and the lower plug (23b) is used to block the left end of the lower slide groove (23a).

4. The one-dimensional adjustable stiffness metamaterial vibration isolation unit according to claim 3, characterized in that: The lower surface of the upper panel (1) is provided with an upper arc plate (12) adapted to the shape of the upper surface of the upper arc hard beam section (21), the upper slide seat (11) is fixed on the lower surface of the upper arc plate (12), the upper surface of the lower panel (3) is provided with a lower arc plate (32) adapted to the shape of the lower surface of the lower arc hard beam section (23), the lower slide seat (31) is fixed on the upper surface of the lower arc plate (32), when the upper arc hard beam section (21) is fixedly matched with the upper panel (1), the upper arc plate (12) conflicts with the upper arc hard beam section (21), when the lower arc hard beam section (23) is fixedly matched with the lower panel (3), the lower arc plate (32) conflicts with the lower arc hard beam section (23).

5. The one-dimensional adjustable stiffness metamaterial vibration isolation unit according to claim 4, characterized in that: The rigidity of the upper arc-shaped hard beam section (21) and the lower arc-shaped hard beam section (23) is greater than that of the middle elastic section (22), and the rigidity of the upper panel (1) and the lower panel (3) is not less than that of the upper arc-shaped hard beam section (21) and the lower arc-shaped hard beam section (23).

6. The one-dimensional adjustable stiffness metamaterial vibration isolation unit according to claim 1, characterized in that: The upper panel (1), the lower panel (3) and the spring curved beam (2) are all manufactured by 3D printing.

7. The one-dimensional adjustable stiffness metamaterial vibration isolation unit according to claim 1, characterized in that: The number of the spring curved beams (2) is multiple, and the arrangement requirement of the spring curved beams (2) between the upper panel (1) and the lower panel (3) is that the connection holes (24) of each spring curved beam (2) are coaxial.

8. The one-dimensional adjustable stiffness metamaterial vibration isolation unit according to claim 1, characterized in that: The upper panel (1) and the lower panel (3) have the same structure, and the upper arc-shaped hard beam section (21) and the lower arc-shaped hard beam section (23) have the same structure.

9. One-dimensional adjustable stiffness metamaterial vibration isolation device, characterized by: The invention is formed by stacking and positioning a plurality of one-dimensionally adjustable stiffness metamaterial vibration isolation units as claimed in claim 1 in sequence, wherein the stacking method is as follows: the upper panel (1) or the lower panel (3) of the one-dimensionally adjustable stiffness metamaterial vibration isolation unit is fixed to the lower panel (3) or the upper panel (1) of the adjacent one-dimensionally adjustable stiffness metamaterial vibration isolation unit.

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