One-dimensional rigidity-adjustable metamaterial vibration isolation unit and vibration isolation device

Abstract

The vibration isolation unit comprises an upper panel, a lower panel and a spring curved beam, the spring curved beam comprises 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 with the upper arc-shaped hard beam section, and the lower end of the middle elastic section is connected with the lower arc-shaped hard beam section; the center of the middle elastic section is overlapped with the arc center of the upper arc-shaped hard beam section and the arc center of the lower arc-shaped hard beam section, the upper arc-shaped hard beam section is connected with the lower surface of the upper panel, the upper arc-shaped hard beam section and the upper panel can be switched between fixed fit and sliding fit, and the lower arc-shaped hard beam section is connected with the upper surface of the lower panel. And the lower arc-shaped hard beam section and the lower panel can be switched between fixed fit and sliding fit. By adjusting the effective supporting rigidity of the spring curved beam, the continuity and smoothness of the rigidity change of the metamaterial are achieved, the large-range change of the rigidity is effectively achieved, and the requirements for the structural rigidity under different working conditions are met.

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 technological development. Vibration not only interferes with human life and affects human health, but also causes buildings, mechanical equipment and precision instruments to be unable to be used normally or even damaged. In the fields of aerospace, automotive engineering, shipbuilding engineering, 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 brought 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 view of the contradictory relationship between bearing and vibration isolation, many researchers have proposed a passive vibration isolation method with quasi-zero stiffness and an active vibration isolation method with adjustable stiffness.

[0003] The invention patent application with application number "CN217301390U" and name "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; in view of the large assembly error, 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 uses the structure of the elastic element itself to achieve the parallel connection of positive and negative stiffness, improves the overall reliability, reduces the manufacturing cost, and effectively achieves low-frequency vibration isolation. Although this patent proposes a quasi-zero stiffness metamaterial with excellent vibration isolation effect, its ability to cope with forces in different environments is limited. When the force is greater than the quasi-zero stiffness equilibrium position, the invention cannot play the role of low-frequency vibration isolation.

[0004] The invention patent application with application number "CN117145936A" and name "An aluminum alloy adjustable stiffness mechanical superstructure" discloses a gear set superstructure that actively controls stiffness; it includes an outer ring gear, an outer planetary gear, inner and outer planetary gears, and a special-shaped sun gear. During operation, the stiffness can be smoothly controlled by manipulating the control hand rudder and the control gear, which solves the defects of the existing adjustable stiffness device, such as difficulty in adjustment and small adjustment range. However, because it uses a gear meshing device, it has high requirements on the strength of the parts, and cannot achieve effective vibration isolation of the structure in a lower frequency band. 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 provide a one-dimensional adjustable stiffness metamaterial vibration isolation unit and a vibration isolation device in view of the above-mentioned existing deficiencies. The present invention has continuous stiffness variation and a wide variation range, and can effectively solve the contradictory 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] A one-dimensional adjustable stiffness metamaterial vibration isolation unit comprises 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 comprises 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 be switched 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 be switched 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 arranged at the center of the middle elastic section.

[0008] To optimize the above technical solutions, the 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 seat is arranged on the lower surface of the upper panel, and an upper slide groove running left and right is arranged on the upper arc-shaped hard beam section. The upper slide seat is stuck in the upper slide groove and slides with the upper slide groove. A lower slide seat is arranged on the upper surface of the lower panel, and a lower slide groove running left and right is arranged on the lower arc-shaped hard beam section. The lower slide seat is stuck in the lower slide groove and slides with the lower slide groove.

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

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

[0013] The rigidity of the upper arc-shaped rigid beam section and the lower arc-shaped rigid beam section is greater than that of the middle elastic section, and the rigidity of the upper panel and the lower panel is not less than that of the upper arc-shaped rigid beam section and the lower arc-shaped rigid 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 formed by stacking and positioning a plurality of one-dimensional adjustable stiffness metamaterial vibration isolation units in sequence, wherein the stacking method is as follows: the upper panel or the lower panel of the one-dimensional adjustable stiffness metamaterial vibration isolation unit is fixed to the lower panel or the 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 change of the stiffness of the metamaterial are achieved, and a wide range of stiffness changes are effectively achieved, which can meet 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, etc.

[0021] (3) The present invention adopts 3D printing technology for processing and assembly, which is convenient for designing 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 a significant design effect, and has certain practical engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0024] Figure 2 1 is a diagram of different stiffness states of the one-dimensional adjustable stiffness metamaterial vibration isolation unit of the present invention, wherein the upper left is a diagram of the overall structure, the upper right is a diagram of the state of the one-dimensional adjustable stiffness metamaterial vibration isolation unit when the structural stiffness is the minimum state; the lower left is a diagram of the intermediate state during the stiffness adjustment process; the lower right is a diagram of the state of the one-dimensional adjustable stiffness metamaterial vibration isolation unit when the structural stiffness is the maximum state;

[0025] Figure 3 Schematic diagram of the upper panel, wherein the upper left is a stereoscopic 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 is a schematic diagram of a spring curved beam, wherein the upper left is a stereoscopic diagram 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 adjustable 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 hard beam section 21, upper slide groove 21a, upper plug 21b, middle elastic section 22, lower arc hard beam section 23, lower slide groove 23a, lower plug 23b, connecting hole 24, lower panel 3, lower slide seat 31, lower arc plate 32. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0030] Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in this field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient content disclosed in this application.

[0031] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0032] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved 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 inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" / "several" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and 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 ordering of 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 arc plate 12. The upper arc 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 arc plate 12. Figure 3 As shown,

[0035] The spring curved beam 2 includes 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, and the spring curved beam 2 is an S-shaped structure as a whole. An upper slide groove 21a and an upper plug 21b are provided on the upper arc-shaped rigid beam section 21, and 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 rigid beam section 21, and the upper plug 21b blocks the right end of the upper slide groove 21a. The lower arc-shaped rigid beam section 23 includes a lower slide groove 23a and a lower plug 23b. The lower slide groove 23a runs left and right, and the lower slide seat 31 is stuck in the lower slide groove 23a and slides with the lower slide groove 23a. The left end of the lower slide groove 23a opens at the left end of the lower arc-shaped rigid beam section 23, and the plug 23b blocks the left end of the lower slide 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 as a whole, and 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, and the spring curved beams 2 are installed anti-symmetrically to ensure that the overall structure does not undergo horizontal deviation when subjected to force.

[0039] During adjustment, the output rod of the external active mechanism is inserted into the connecting hole 24, and the two S-shaped spring curved beams 2 are adjusted 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 performing structural design, the overall size of the complete one-dimensional adjustable stiffness metamaterial vibration isolation unit is first determined, and the relative positions of the upper slide 11, the upper arc plate 12, the lower slide 31, and the lower arc plate 32 are determined. Secondly, the size and shape of the S-shaped spring curved beam 2 are designed, including the diameter, thickness and width of the curved beam. The size of the upper and lower slide grooves is determined according to 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 seat and the slide groove match to ensure smooth installation and adjustment.

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

[0042] S1, based on the designed adjustable stiffness metamaterial, considering that the upper and lower panels are reliably connected to the S-shaped spring curved beam and can slide flexibly, it is 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 conditions.

[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 on acceleration excitation is tested.

[0045] This design consumes vibration energy through the elastic deformation of the S-shaped spring curved beam, achieving a structure with large deformation and adjustable capabilities, 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 by modifying the material and geometry according to the specific environment, including the diameter, width and thickness of the S-shaped spring curved beam, and 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), wherein 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), wherein 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), and 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), and the upper arc-shaped hard beam section (21) and the upper panel (1) are connected to each other. ) is connected to the lower surface of the upper panel (1), the upper arc-shaped hard beam section (21) and the upper panel (1) can switch between fixed cooperation and sliding cooperation, the lower arc-shaped hard beam section (23) is connected to the upper surface of the lower panel (3), 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, and a connecting hole (24) is provided at the center of the middle elastic section (22).

2. The one-dimensional adjustable stiffness metamaterial vibration isolation unit according to claim 1, characterized in that: 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.

3. The one-dimensional adjustable stiffness metamaterial vibration isolation unit according to claim 2, 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).

4. The one-dimensional adjustable stiffness metamaterial vibration isolation unit according to claim 3 is characterized by: The right end of the upper slide groove (21a) opens at 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 at 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).

5. The one-dimensional adjustable stiffness metamaterial vibration isolation unit according to claim 4 is characterized by: 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-shaped 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-shaped 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-shaped hard beam section (21) is fixedly matched with the upper panel (1), the upper arc plate (12) is in conflict with the upper arc-shaped hard beam section (21); when the lower arc-shaped hard beam section (23) is fixedly matched with the lower panel (3), the lower arc plate (32) is in conflict with the lower arc-shaped hard beam section (23).

6. The one-dimensional adjustable stiffness metamaterial vibration isolation unit according to claim 5, 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).

7. 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.

8. 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.

9. 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.

10. One-dimensional adjustable stiffness metamaterial vibration isolation device, characterized by: The one-dimensional adjustable stiffness metamaterial vibration isolation unit is formed by stacking and positioning a plurality of the one-dimensional 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-dimensional adjustable stiffness metamaterial vibration isolation unit is fixed to the lower panel (3) or the upper panel (1) of the adjacent one-dimensional adjustable stiffness metamaterial vibration isolation unit.

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