Inner and outer double-layer negative stiffness nonlinear energy trap composite vibration damper

Abstract

The utility model relates to the field of engineering structure vibration reduction control, in particular to an inner and outer layer negative stiffness nonlinear energy trap composite vibration reduction device which comprises a device bottom plate, an outer layer energy trap and an inner layer energy trap, and the outer layer energy trap and the inner layer energy trap are arranged on the device bottom plate in a central symmetry mode. The outer layer energy trap and the inner layer energy trap are connected through a vibration reduction assembly, and the inner layer energy trap and the center of the device bottom plate are connected through a vibration reduction assembly. The method is used for solving the problem of nonuniformity of vibration frequency response in an existing nonlinear energy trap technology so as to improve the vibration reduction performance and reduce the economic cost at the same time. The frequency adaptability and the efficiency of the damping device are improved through the double-layer energy traps, and vibration energy of different frequencies is effectively dissipated; through the connection of the damping assemblies, the structure of the damping device is simplified, and the maintenance cost of the damping device is reduced; due to the design direction of a nonlinear spring and a viscous damper in the vibration reduction assembly, the energy capture and dissipation efficiency of the vibration reduction assembly is improved.

Description

Technical Field

[0001] This utility model relates to the field of vibration reduction and control of engineering structures, and more specifically, to a composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps. Background Art

[0002] Energy dissipation technology is a widely used vibration control technique in engineering structures. It aims to reduce the dynamic response of a structure by consuming its vibrational energy. Common dampers include viscous dampers, metallic dampers, and friction dampers. However, due to the limited damping capacity of dampers, they may not be able to completely eliminate structural vibrations in extreme situations such as strong earthquakes or windstorms, thus failing to meet structural safety requirements. Furthermore, the vibration reduction capacity of dampers varies significantly at different vibration frequencies, and they may not achieve ideal vibration reduction effects in low-frequency vibration environments. Therefore, base isolation technology has emerged as a solution.

[0003] Base isolation technology refers to the installation of a seismic isolation layer between the foundation and the superstructure of a building. The isolation layer typically uses elastic elements such as rubber seismic isolation bearings or sliding bearings. Base isolation technology places extremely strict requirements on the selection of seismic isolation bearings, the arrangement of the isolation layer, and the parameter settings. If the isolation layer is not designed properly, it may fail during an earthquake. Furthermore, seismic isolation technology primarily targets vibrations caused by earthquakes; its vibration reduction effect is not significant for vibrations caused by other factors such as wind loads. Moreover, the implementation of seismic isolation technology requires high-quality seismic isolation bearings and related equipment, resulting in high costs and making it difficult to implement for projects with limited economic resources.

[0004] Vibration control technology is a method to reduce or eliminate structural vibration by applying external control measures. It has wide applications in engineering, particularly in high-rise buildings, bridges, and mechanical engineering. While advanced vibration control technologies have advantages, they also face some challenges. Firstly, they rely on complex control algorithms and require high-performance computing equipment, often proving difficult to implement effectively in real-time due to computational resource limitations in practical engineering. Secondly, under different environmental conditions, especially with significant variations in temperature and humidity, the performance of sensors and control components is easily affected, negatively impacting the overall performance of the vibration control system. Nonlinear energy trap (NES) technology is an emerging vibration control technology that utilizes the characteristics of nonlinear systems to achieve effective control of structural vibration. NES technology typically requires a large additional mass block to achieve good vibration reduction, and due to the non-uniformity of the vibration frequency response, the vibration reduction effect may be less than expected in certain frequency ranges. In some practical engineering projects, this may be limited by spatial layout constraints and suboptimal frequency response, affecting the overall effect and increasing the difficulty and cost of the project.

[0005] In summary, traditional vibration dampers cannot achieve ideal vibration reduction effects in low-frequency vibration environments; existing vibration control technologies rely on complex control algorithms, and the operation of computing equipment is greatly affected by the working environment, resulting in unstable performance of the vibration control system; the vibration reduction effect of nonlinear energy trap technology requires a large additional mass block, otherwise the response to vibration frequency is uneven; how to overcome the uneven response to vibration frequency in existing nonlinear energy trap technology, so as to improve vibration reduction performance while reducing economic costs, is a technical problem that urgently needs to be solved in this field. Utility Model Content

[0006] This invention aims to overcome at least one of the defects (deficiencies) of the prior art mentioned above, and provides a composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps. This device addresses the problem that traditional vibration dampers cannot achieve ideal vibration reduction effects in low-frequency vibration environments; existing vibration control technologies rely on complex control algorithms, and the operation of computing equipment is greatly affected by the working environment, leading to unstable performance of the vibration control system; the vibration reduction effect of nonlinear energy trap technology requires a large additional mass block, otherwise the response to vibration frequency is uneven; and the invention addresses how to overcome the unevenness of the vibration frequency response in existing nonlinear energy trap technology to improve vibration reduction performance while reducing economic costs.

[0007] The technical solution adopted by this utility model is to provide a composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps, which includes a device base plate and an outer layer energy trap and an inner layer energy trap symmetrically arranged on the device base plate. The inner layer energy trap and the outer layer energy trap are concentrically connected from the inside to the outside of the center of the device base plate. The outer layer energy trap and the inner layer energy trap, as well as the inner layer energy trap and the center of the device base plate, are connected by vibration reduction components.

[0008] This method is beneficial for suppressing the vibration of the main structure, i.e., the base plate of the device, by utilizing the redistribution of vibration energy through nonlinear energy traps. Since the structural frequency ratio of a single-layer nonlinear energy trap is 1:N, and the structural frequency ratio of the first-level NES to the second-level NES is 1:M, when the second-level NES is nested within the first-level NES, the frequency ratio of the original single NES to the main structure is transformed from 1:N to 1:NM through the double-layer nonlinear energy traps. This improves the frequency adaptability and efficiency of the vibration damping device and effectively dissipates vibration energy of different frequencies. At the same time, the double-layer energy traps are connected by vibration damping components, which further improves the vibration damping performance while simplifying the structure of the vibration damping device and reducing the maintenance cost of the vibration damping device.

[0009] Furthermore, the outer energy sink includes a fixed plate, a primary NES mass block, and a primary NES track. The fixed plate is fixed to the device base plate and connected to the primary NES mass block via the primary NES track. The inner energy sink includes a secondary NES mass block and a secondary NES track. The primary NES mass block is connected to the secondary NES mass block via the secondary NES track, and the secondary NES mass block and the primary NES mass block are concentrically connected.

[0010] It is beneficial to conduct the vibration frequency of the main structure in one direction through the fixed plate. The outer layer of the energy dissipation and vibration reduction device formed by the first-level NES mass block and the first-level NES track has nonlinear stiffness, and the inner layer of the energy dissipation and vibration reduction device formed by the second-level NES mass block and the second-level NES track has nonlinear stiffness. It not only achieves the characteristics of wide vibration reduction frequency band and good robustness, but also realizes the concentric design of double-layer energy trap to improve the adaptability to a wider vibration frequency band in the main structure.

[0011] Furthermore, the vibration damping assembly includes a viscous damper and a nonlinear spring, and the fixed plate includes two long plates and two short plates. The two long plates are symmetrically arranged on both sides of the center of the device base plate, and the two short plates are symmetrically arranged on both sides of the center of the device base plate. The viscous damper is used to connect the long plates, and the nonlinear spring is used to connect the short plates.

[0012] It is beneficial to achieve energy dissipation and vibration reduction by using viscous dampers to achieve vibration energy transmitted unidirectionally along the long plate direction, and to achieve vibration absorption and vibration reduction by using nonlinear springs to achieve vibration energy transmitted unidirectionally along the short plate direction. The combination of viscous dampers and nonlinear springs forms a coupling effect, which optimizes the vibration frequency of the vibration reduction component.

[0013] Furthermore, the viscous damper is coaxially connected to the first-stage NES mass block and the second-stage NES mass block respectively, forming a first axis; the nonlinear spring is coaxially connected to the first-stage NES mass block and the second-stage NES mass block respectively, forming a second axis; the first axis and the second axis are perpendicular to each other.

[0014] It is advantageous to achieve vibration reduction by dissipating vibration energy in the coaxial direction through the coaxial connection of the viscous damper with the first-stage NES mass block and the second-stage mass block, and to achieve vibration reduction by absorbing vibration energy in the coaxial direction through the coaxial connection of the nonlinear spring with the first-stage NES mass block and the second-stage mass block. The mutual perpendicularity of the two axes gives the nonlinear energy trap negative stiffness characteristics, thus exhibiting better energy capture and dissipation capabilities.

[0015] Furthermore, the viscous damper includes an outer damper and an inner damper. The outer damper and the first-stage NES track are connected side-by-side to the outside of the first-stage NES mass block. The inner damper and the second-stage NES track are connected side-by-side to the inside of the first-stage NES mass block and the outside of the second-stage NES mass block.

[0016] This facilitates the synergistic effect of the outer and inner dampers to form a nonlinear energy trap, creating a two-level energy dissipation mechanism.

[0017] Furthermore, the nonlinear spring includes an outer spring and an inner spring. The outer spring is connected to the outside of the first-stage NES mass block, and the inner spring is connected to the inside of the first-stage NES mass block and the outside of the second-stage NES mass block.

[0018] This facilitates the synergistic effect of the outer and inner springs to form a nonlinear energy trap, creating a two-level energy absorption mechanism.

[0019] Furthermore, one end of the outer damper is connected to the long plate by a hexagonal bolt, and the other end is connected to the first-stage NES mass block by a round bolt; one end of the inner damper is connected to the outer damper by a round bolt, and the other end is connected to the second-stage NES mass block by a hexagonal bolt.

[0020] The hexagonal bolts facilitate tightening and loosening between the long plate and the outer damper, while the round bolts reduce stress concentration between the outer damper and the first-stage NES mass block; the hexagonal bolts also facilitate tightening and loosening between the second-stage NES mass block and the inner damper, while the round bolts reduce stress concentration between the inner and outer dampers.

[0021] Furthermore, one end of the outer spring is connected to the short plate by a hexagonal bolt, and the other end is connected to the primary NES mass block by a fixing washer; both ends of the inner spring are connected to the primary NES mass block and the secondary NES mass block respectively by fixing washers.

[0022] The hexagonal bolts facilitate the tightening and loosening of the short plate and the outer spring, and the fixed shims enhance the sealing between the outer spring and the first-stage NES mass block. The fixed shims also enhance the sealing between the inner spring and the first-stage and second-stage NES mass blocks respectively, preventing torsion and slippage from affecting the vibration absorption effect.

[0023] Furthermore, the two ends of the primary NES track are respectively connected to the long plate and the primary NES mass block by hexagonal bolts; the two ends of the secondary NES track are respectively connected to the primary NES mass block and the secondary NES mass block by round bolts.

[0024] The use of hexagonal bolts facilitates the tightening and loosening of the primary NES track with the long plate and the primary NES mass block, respectively; while the use of round bolts reduces stress concentration between the secondary NES track and the primary NES mass block and the secondary NES mass block, respectively.

[0025] Furthermore, rolling bearings are provided on the outer side of the first-stage NES mass block. The rolling bearings include two, which are respectively connected to the first-stage NES tracks on both sides of the outer damper, and are used to control the rotation accuracy of the first-stage NES tracks.

[0026] It is beneficial to eliminate the gap between the first-stage NES mass block and the first-stage NES track by using rolling bearings, which improves rotational accuracy, allows for flexible start-up while bearing radial and axial loads, and simplifies the support structure.

[0027] Compared with the prior art, the beneficial effects of this utility model are as follows: by using a double-layer energy trap, the frequency ratio of the original single NES to the main structure is transformed from 1:N to 1:NM, which improves the frequency adaptability and efficiency of the vibration damping device and effectively dissipates vibration energy of different frequencies; at the same time, the double-layer energy traps are connected by vibration damping components, which further improves the vibration damping performance while simplifying the structure of the vibration damping device and reducing the maintenance cost of the vibration damping device; and the design direction of the nonlinear spring and viscous damper in the vibration damping components improves the energy capture and dissipation efficiency of the vibration damping components. Attached Figure Description

[0028] Figure 1 This is a top view of the structure of this utility model.

[0029] Figure 2 This is a frontal view of the present invention.

[0030] Figure 3 This is a schematic diagram of the first-level NES mass block of this utility model.

[0031] Figure 4 This is a schematic diagram of the secondary NES mass block of this utility model.

[0032] Figure 5 This is a schematic diagram showing the connection between the viscous damper and the hexagonal bolt of this utility model.

[0033] Figure 6 This is a schematic diagram showing the connection between the viscous damper and the circular bolt of this utility model.

[0034] Figure 7 This is a schematic diagram of the connection of the nonlinear spring of this utility model.

[0035] Figure 8 This is a schematic diagram of the first-stage NES track connection of this utility model.

[0036] Figure 9 This is a schematic diagram of the secondary NES track connection of this utility model.

[0037] Explanation of the symbols in the attached diagram: 1. Base plate of the device; 2. Fixed structure plate; 3. Primary NES track; 4. Nonlinear spring; 5. Hexagonal bolt; 6. Viscous damper; 7. Primary NES mass block; 8. Secondary NES mass block; 9. Secondary NES track; 10. Rolling bearing; 11. Circular bolt; 12. Nonlinear spring fixing washer; 13. Mass block addition area. DETAILED DESCRIPTION

[0038] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this invention. To better illustrate the following embodiments, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0039] Example

[0040] like Figure 1-9 As shown, this embodiment provides a composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps, which includes a device base plate 1, and an outer energy trap and an inner energy trap symmetrically arranged on the device base plate 1. The inner energy trap and the outer energy trap are concentrically connected from the inside to the outside of the center of the device base plate 1. The outer energy trap and the inner energy trap, as well as the inner energy trap and the center of the device base plate 1, are connected by vibration reduction components.

[0041] In this embodiment, the nonlinear energy trap composite vibration damping device is cubic in shape, with an outer energy trap and an inner energy trap arranged sequentially from the outside to the inside within the cube. The base plate 1 of the device is square in shape. The top view of the outer energy trap includes a square-shaped primary NES mass block 7 located at the center of the base plate 1, and vibration damping components arranged around the perimeter of the cube. The inner energy trap is located at the center of the outer energy trap. The top view of the inner energy trap includes a square-shaped secondary NES mass block 8 located at the center of the base plate 1, and vibration damping components arranged around the perimeter of the cube. The vibration damping components in the outer energy trap and the vibration damping components in the inner energy trap have the same configuration structure, consisting of two nonlinear springs 4 and two viscous dampers 6 located on opposite sides of the cube. The two nonlinear springs 4 and the two viscous dampers 6 are connected at the center of a cross to achieve synergistic effect, broadening the frequency response range and thus providing a stable and efficient vibration damping effect under different frequency excitations. The nonlinear energy trap composite vibration reduction device is installed on the top floor of the building and can effectively reduce vibration in the building.

[0042] The outer energy sink includes a fixed plate 2, a primary NES mass block 7, and a primary NES track 3. The fixed plate 2 is fixed to the device base plate 1 and is connected to the primary NES mass block 7 via the primary NES track 3. The inner energy sink includes a secondary NES mass block 8 and a secondary NES track 9. The primary NES mass block 7 is connected to the secondary NES mass block 8 via the secondary NES track 9. The secondary NES mass block 8 and the primary NES mass block 7 are concentrically connected.

[0043] In this embodiment, the fixed plate 2 is rectangular and is fixedly connected to the device base plate 1 via a triangular support plate. The primary NES track 3 is located between the fixed plate 2 and the primary NES mass block 7. The primary NES track 3 comprises four tracks, with two centrally symmetrical tracks on each opposite side of the primary NES mass block 7. The secondary NES track 9 is located between the fixed plate 2 and the secondary NES mass block 8. The secondary NES track 9 comprises four tracks, with two centrally symmetrical tracks on each opposite side of the secondary NES mass block 8. The secondary NES track 9 is offset from the primary NES track 3 along the line of symmetry to avoid interference caused by stress on the double-layer track. The secondary NES mass block 8 is concentrically connected to the primary NES mass block 7. The secondary NES mass block 8 is a cube, and the primary NES mass block 7 is a square frame. The concentric connection point is the mass block addition area 13. The weight of the mass block is replaceable to accommodate a wider vibration frequency filtering range.

[0044] The vibration damping assembly includes a viscous damper 6 and a nonlinear spring 4. The fixed plate 2 includes two long plates and two short plates. The two long plates are symmetrically arranged on both sides of the center of the device base plate 1, and the two short plates are symmetrically arranged on both sides of the center of the device base plate 1. The viscous damper 6 is used to connect the long plates, and the nonlinear spring 4 is used to connect the short plates.

[0045] In this embodiment, the fixed plate 2 includes two long plates and two short plates. The long plates are fixed to the device base plate 1 by four triangular support plates, which form three zones on the back side of the long plates away from the mass addition area 13. The short plates are fixed to the device base plate 1 by two triangular support plates, which form one zone on the back side of the short plates away from the mass addition area 13. The viscous damper 6 is connected to the side of the long plates near the mass addition area 13; the nonlinear spring 4 is connected to the side of the short plates near the mass addition area 13.

[0046] The viscous damper 6 is coaxially connected to the first-stage NES mass block 7 and the second-stage NES mass block 8, forming a first axis; the nonlinear spring 4 is coaxially connected to the first-stage NES mass block 7 and the second-stage NES mass block 8, forming a second axis; the first axis and the second axis are perpendicular to each other.

[0047] In this embodiment, the viscous damper 6 comprises four units: two symmetrically connected to the upper and lower opposite sides of the first-stage NES mass block 7, and two symmetrically connected to the upper and lower opposite sides of the second-stage NES mass block 8. The nonlinear spring 4 comprises four units: two symmetrically connected to the left and right opposite sides of the first-stage NES mass block 7, and two symmetrically connected to the left and right opposite sides of the second-stage NES mass block 8. The upper and lower, left and right directions of the first-stage NES mass block 7 and the second-stage NES mass block 8 are all in the same direction, and the upper and lower directions and the left and right directions are perpendicular to each other on the plane of the device base plate 1.

[0048] The viscous damper 6 includes an outer damper and an inner damper. The outer damper and the first-stage NES track 3 are connected side-by-side to the outside of the first-stage NES mass block 7. The inner damper and the second-stage NES track 9 are connected side-by-side to the inside of the first-stage NES mass block 7 and the outside of the second-stage NES mass block 8.

[0049] In this embodiment, the outer damper includes two in the vertical direction. One end of the outer damper is connected to the long plate, and the other end is connected to the back side of the first-stage NES mass 7 away from the mass addition area 13. The inner damper includes two in the vertical direction. One end of the inner damper is connected to the face side of the first-stage NES mass 7 near the mass addition area 13, and the other end is connected to the back side of the second-stage NES mass 8 away from the mass addition area 13. Two first-stage NES tracks 3 are arranged in parallel on the left and right sides of each outer damper, and two second-stage NES tracks 9 are arranged in parallel on the left and right sides of each inner damper.

[0050] The nonlinear spring 4 includes an outer spring and an inner spring. The outer spring is connected to the outside of the first-stage NES mass block 7, and the inner spring is connected to the inside of the first-stage NES mass block 7 and the outside of the second-stage NES mass block 8.

[0051] In this embodiment, the outer spring includes two springs in the left-right direction. One end of the outer spring is connected to the short plate, and the other end is connected to the back side of the first-level NES mass block 7 away from the mass block addition area 13. The inner spring includes two springs in the left-right direction. One end of the inner spring is connected to the face side of the first-level NES mass block 7 near the mass block addition area 13, and the other end is connected to the back side of the second-level NES mass block 8 away from the mass block addition area 13.

[0052] One end of the outer damper is connected to the long plate by a hexagonal bolt 5, and the other end is connected to the first-stage NES mass block 7 by a round bolt 11; one end of the inner damper is connected to the outer damper by a round bolt 11, and the other end is connected to the second-stage NES mass block 8 by a hexagonal bolt 5.

[0053] In this embodiment, two hexagonal bolts 5 are installed between the long plate and the outer damper, respectively located in the middle area of ​​the back side of the two long plates. The specific shape of the hexagonal bolts 5 makes the disassembly and assembly of the outer damper more convenient. Two circular bolts 11 are installed between the outer damper and the first-stage NES mass block 7, respectively located in the vertical direction on the back side of the first-stage NES mass block 7 away from the mass block addition area 13. Two circular bolts 11 are installed between the inner damper and the first-stage NES mass block 7, respectively located in the vertical direction on the face side of the first-stage NES mass block 7 near the mass block addition area 13. Two hexagonal bolts 5 are installed between the inner damper and the second-stage NES mass block 8, respectively located in the vertical direction on the back side of the second-stage NES mass block 8 away from the mass block addition area 13.

[0054] One end of the outer spring is connected to the short plate by a hexagonal bolt 5, and the other end is connected to the first-stage NES mass block 7 by a fixing washer 12; the two ends of the inner spring are respectively connected to the first-stage NES mass block 7 and the second-stage NES mass block 8 by fixing washers 12.

[0055] In this embodiment, two hexagonal bolts 5 are installed between the short plate and the outer spring, respectively located in a region on the back side of the two short plates. The specific shape of the hexagonal bolts 5 makes the assembly and disassembly of the outer spring more convenient. Two fixing shims 12 are installed between the outer spring and the first-stage NES mass block 7, respectively located in the left and right directions on the back side of the first-stage NES mass block 7 away from the mass block addition area 13. Two fixing shims 12 are installed between the inner spring and the first-stage NES mass block 7, respectively located in the left and right directions on the face side of the first-stage NES mass block 7 near the mass block addition area 13; two fixing shims 12 are installed between the inner spring and the second-stage NES mass block 8, respectively located in the left and right directions on the back side of the second-stage NES mass block 8 away from the mass block addition area 13.

[0056] The two ends of the primary NES track 3 are connected to the long plate and the primary NES mass block 7 respectively by hexagonal bolts 5; the two ends of the secondary NES track 9 are connected to the primary NES mass block 7 and the secondary NES mass block 8 respectively by round bolts 11.

[0057] In this embodiment, the primary NES track 3 comprises four sections, and the hexagonal bolts 5 installed on the primary NES track 3 and the long plate comprise eight sections, four of which are located on the back side of the two long plates, and the other four are located in the vertical direction on the back side of the primary NES mass block 7 away from the mass block addition area 13. The specific shape of the hexagonal bolts 5 makes the assembly and disassembly of the primary NES track 3 more convenient. The secondary NES track 9 comprises four sections, and the circular bolts 11 installed on the secondary NES track 9 and the primary NES mass block 7 comprise eight sections, four of which are located in the vertical direction on the face of the primary NES mass block 7 near the mass block addition area 13, and the other four are located in the vertical direction on the back side of the secondary NES mass block 8 away from the mass block addition area 13.

[0058] The outer side of the first-stage NES mass block 7 is provided with rolling bearings 10. There are two rolling bearings 10, which are respectively connected to the first-stage NES tracks 3 on both sides of the outer damper, and are used to control the rotation accuracy of the first-stage NES tracks 3.

[0059] In this embodiment, four rolling bearings 10 are provided, with one rolling bearing 10 at the connection between each primary NES track 3 and the primary NES mass block 7. The rolling bearings 10 not only improve the rotational accuracy of the primary NES track 3, but also make the start-up of the primary NES track 3 more flexible, so that both the radial and axial loads of the primary track 3 and the primary NES mass block 7 are supported.

[0060] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the technical solution of this utility model, and are not intended to limit the specific implementation of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps, characterized in that, The device includes a base plate (1) and an outer energy trap and an inner energy trap that are symmetrically arranged on the base plate (1). The inner energy trap and the outer energy trap are concentrically connected from the inside to the outside of the center of the base plate (1). The outer energy trap and the inner energy trap, as well as the inner energy trap and the center of the base plate (1), are connected by vibration damping components.

2. The composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps according to claim 1, characterized in that, The outer energy sink includes a fixed plate (2), a primary NES mass block (7), and a primary NES track (3). The fixed plate (2) is fixed on the device base plate (1) and connected to the primary NES mass block (7) through the primary NES track (3). The inner energy sink includes a secondary NES mass block (8) and a secondary NES track (9). The primary NES mass block (7) is connected to the secondary NES mass block (8) through the secondary NES track (9). The secondary NES mass block (8) and the primary NES mass block (7) are concentrically connected.

3. The composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps according to claim 2, characterized in that, The vibration damping assembly includes a viscous damper (6) and a nonlinear spring (4). The fixed plate (2) includes two long plates and two short plates. The two long plates are symmetrically arranged on both sides of the center of the device base plate (1), and the two short plates are symmetrically arranged on both sides of the center of the device base plate (1). The viscous damper (6) is used to connect the long plates, and the nonlinear spring (4) is used to connect the short plates.

4. The composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps according to claim 3, characterized in that, The viscous damper (6) is coaxially connected to the first-stage NES mass block (7) and the second-stage NES mass block (8) to form a first axis; the nonlinear spring (4) is coaxially connected to the first-stage NES mass block (7) and the second-stage NES mass block (8) to form a second axis; the first axis and the second axis are perpendicular to each other.

5. The composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps according to claim 3, characterized in that, The viscous damper (6) includes an outer damper and an inner damper. The outer damper and the first-stage NES track (3) are connected side by side to the outside of the first-stage NES mass block (7). The inner damper and the second-stage NES track (9) are connected side by side to the inside of the first-stage NES mass block (7) and the outside of the second-stage NES mass block (8).

6. The composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps according to claim 3, characterized in that, The nonlinear spring (4) includes an outer spring and an inner spring. The outer spring is connected to the outside of the first-stage NES mass block (7), and the inner spring is connected to the inside of the first-stage NES mass block (7) and the outside of the second-stage NES mass block (8).

7. The composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps according to claim 5, characterized in that, One end of the outer damper is connected to the long plate by a hexagonal bolt (5), and the other end is connected to the first-stage NES mass block (7) by a round bolt (11); one end of the inner damper is connected to the outer damper by a round bolt (11), and the other end is connected to the second-stage NES mass block (8) by a hexagonal bolt (5).

8. The composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps according to claim 6, characterized in that, One end of the outer spring is connected to the short plate by a hexagonal bolt (5), and the other end is connected to the first-level NES mass block (7) by a fixing washer (12); the two ends of the inner spring are connected to the first-level NES mass block (7) and the second-level NES mass block (8) respectively by fixing washers (12).

9. The composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps according to any one of claims 3-8, characterized in that, The two ends of the primary NES track (3) are connected to the long plate and the primary NES mass block (7) respectively by hexagonal bolts (5); the two ends of the secondary NES track (9) are connected to the primary NES mass block (7) and the secondary NES mass block (8) respectively by round bolts (11).

10. The composite vibration reduction device with inner and outer double-layer negative stiffness nonlinear energy traps according to claim 9, characterized in that, The outer side of the first-stage NES mass block (7) is provided with rolling bearings (10). There are two rolling bearings (10), which are respectively connected to the first-stage NES tracks (3) on both sides of the outer damper and are used to control the rotation accuracy of the first-stage NES tracks (3).

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