Graded variable-damping variable-rigidity pendulum type damping device and vibration reduction configuration method thereof

Abstract

The invention provides a graded variable-damping variable-rigidity pendulum type damping device and a vibration attenuation configuration method, the device comprises a damping mounting frame, a single mass block, a vertical guide piece, a nonlinear damping unit, a rigidity adjusting unit and a linear damping unit, and a lower permanent magnet assembly or a lower conductor assembly of the linear damping unit and the single mass block are horizontally limited and vertically decoupled. The method comprises the steps that the swing arm swing length, the horizontal limit displacement and the vertical limit displacement of a single mass block and the optimal damping ratio of a linear damping unit are determined, an optimal damping coefficient determined through the optimal damping ratio is set as a basic damping coefficient, and a nonlinear damping coefficient is increased and adjusted through a nonlinear damping unit on the basis of the basic damping coefficient; and the preset horizontal displacement and the preset vertical displacement of the single mass block are configured according to the horizontal limit displacement of the single mass block. The damping device has the advantages that the damping coefficient is stable when the amplitude is small, and sufficient damping can be provided under extreme conditions.

Description

Technical Field

[0001] The invention relates to the field of vibration reduction and damping, and in particular to a graded variable damping and variable stiffness pendulum damping device and a vibration reduction configuration method thereof. Background Art

[0002] High-rise buildings and wind turbine towers vibrate significantly under strong winds and earthquakes, and the vibration direction is random. For such structures, the pendulum tuned mass damper (PTMD) is an ideal energy absorption and vibration reduction device. The damping elements of existing PTMDs are usually oil damping, eddy current damping, etc. In the traditional eddy current form of PTMD, a permanent magnet is installed at the bottom of the mass block, and a conductor plate is installed below. The gap between the permanent magnet and the conductor plate is constant, so the damping coefficient is a constant value, the damping is easy to adjust, and the energy dissipation is uniform. However, when the structure is in an extreme environment and oscillates greatly, it may not be enough to quickly attenuate the amplitude, resulting in an oscillation duration that is too long. The amplitude of the PTMD mass block is very easy to exceed the limit, which is easy to cause collision with the inside of the controlled structure (such as the PTMD mass block inside the tower collides with the tower wall), thereby causing PTMD detuning, causing damage to the controlled structure, and causing system instability or performance degradation. At the same time, the linear PTMD (usually expressed as linear stiffness) has a narrow control band and its control effect is limited for structures with time-varying dynamic characteristics or multi-order mode participation.

[0003] In order to solve the above technical problems, the existing method is to use PTMD with nonlinear damping force or nonlinear stiffness. Among them, the PTMD with nonlinear damping force realizes the nonlinear change of damping coefficient with the swing amplitude of the mass block through the relative movement of the mass block, but the existing PTMD with nonlinear damping force has a nonlinear damping coefficient when the displacement amplitude is small, and its vibration reduction performance is poor at small amplitudes, which makes the oscillation attenuation process poorly stable, resulting in unstable system response, and its energy dissipation capacity is poor compared with the traditional linear damping force PTMD. The stiffness coefficient of the PTMD with nonlinear stiffness shows nonlinearity as the amplitude increases, and its stiffness coefficient is the square of the amplitude displacement. Its control band is wider, but its robustness is highly dependent on the design of nonlinear mechanisms (such as bistable, negative stiffness), while the robustness of linear PTMD to a single frequency under strict tuning conditions is easier to predict. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a graded variable damping and variable stiffness pendulum damping device and a vibration reduction configuration method thereof, which can ensure the stability of the damping coefficient at small amplitudes and provide sufficient energy dissipation capacity under extreme conditions.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is: A hierarchical variable-damping and variable-stiffness pendulum damping device, comprising a damping mounting frame, a single mass block swingably mounted on the damping mounting frame, a plurality of vertical guiding members passing through the single mass block, a non-linear damping unit and a stiffness adjusting unit provided between the single mass block and the vertical guiding members, and a linear damping unit provided below the single mass block. Among them, the linear damping unit includes a lower permanent magnet assembly and a lower conductor assembly arranged oppositely with a constant gap, and the lower permanent magnet assembly or the lower conductor assembly is horizontally limited and vertically decoupled from the single mass block through the vertical guiding members; the non-linear damping unit generates non-linear eddy current damping when the single mass block swings to a first critical height, and the linear damping unit always generates linear eddy current damping when the single mass block swings; the stiffness adjusting unit generates non-linear stiffness when the single mass block swings to a second critical height.

[0006] As a further improvement of the above technical solution: A linear damping gap is left between the single mass block and the lower permanent magnet assembly. When the single mass block moves from the initial state to when the linear damping gap is 0, the lower permanent magnet assembly and the lower conductor assembly move parallel to generate linear damping; when the single mass block continues to move upward, the non-linear damping unit generates non-linear eddy current damping.

[0007] The non-linear damping unit includes an upper permanent magnet group and an upper conductor plate. The upper permanent magnet group is provided at the upper end of the vertical guiding member, and the upper conductor plate is provided in the through hole of the single mass block passing through the vertical guiding member. The upper conductor plate cuts the magnetic induction line to generate eddy current when moving to the upper permanent magnet group; the first critical height is the initial distance between the lower end face of the upper permanent magnet group and the upper end face of the upper conductor plate, and the first critical height is equal to the linear damping gap in the initial state of the single mass block. The sum of the linear damping gap in the initial state of the single mass block and the axial length of the upper permanent magnet group is greater than the vertical extreme displacement of the single mass block.

[0008] The actual horizontal displacement of the single mass block and the damping coefficient of the damping device satisfy the following relationship: Among them, is the damping coefficient of the damping device, is the optimal damping coefficient of the linear damping unit, is the non-linear damping coefficient generated by the upper conductor plate cutting the upper permanent magnet group, is the preset horizontal displacement of the single mass block when the upper conductor plate starts to cut the magnetic induction line, is the actual horizontal displacement of the single mass block, is the swing arm length of the single mass block, is the preset vertical displacement when the single mass block starts to cut the magnetic induction line on the upper conductor plate, is the preset axial length of the upper permanent magnet group, is the actual vertical displacement of the single mass block.

[0009] The stiffness adjustment unit includes an adjustment spring and a limiting part that is in limit cooperation with the adjustment spring. The adjustment spring is arranged at the upper end of the vertical guide, and the limiting part is the upper end surface of the single mass block. The second critical height is the initial distance between the lower end surface of the adjustment spring and the upper end surface of the single mass block; when the single mass block swings to the second critical height, the upper end surface of the single mass block contacts the adjustment spring and generates non-linear stiffness; the sum of the second critical height and the axial length of the adjustment spring is greater than the vertical extreme displacement of the single mass block.

[0010] The actual horizontal displacement of the single mass block and the stiffness coefficient of the damping device satisfy the following relationship: where, is the stiffness coefficient of the damping device, is the optimal stiffness coefficient of the single mass block, is the stiffness coefficient of the adjustment spring, is the actual horizontal displacement of the single mass block, is the preset horizontal displacement when the upper end surface of the single mass block starts to contact the adjustment spring, is the swing arm length of the single mass block, is the preset vertical displacement when the upper end surface of the single mass block starts to contact the adjustment spring, is the preset axial length of the adjustment spring, is the actual vertical displacement of the single mass block.

[0011] The non-linear damping unit and the stiffness adjustment unit are alternately arranged at intervals along the outer periphery of the single mass block; the second critical height is greater than or equal to the first critical height.

[0012] A multi-directional guiding component for ensuring the constant gap between the lower permanent magnet component and the lower conductor component is provided between the lower permanent magnet component and the lower conductor component. The multi-directional guiding component includes two groups of rail components arranged crosswise and sliding relative to each other. The lower permanent magnet component is slidably connected to the upper rail component, and the lower rail component is fixedly installed on the lower conductor component.

[0013] A vibration reduction configuration method for the above-mentioned hierarchical variable damping and variable stiffness pendulum damping device includes: According to the mass of the single mass block and the modal mass of the target mode of the controlled structure Calculate the mass ratio , and determine the swing arm length of the single mass block according to the mass ratio ; determine the optimal damping ratio of the linear damping unit ; measure the horizontal extreme displacement of the single mass block , and determine the vertical extreme displacement of the single mass block according to the swing arm length of the single mass block and the horizontal extreme displacement of the single mass block ; Determine the vertical extreme displacement of the single mass block ; Calculate the optimal damping coefficient of the linear damping unit according to the optimal damping ratio of the linear damping unit , and set the optimal damping coefficient of the linear damping unit as the basic damping coefficient; adjust any one or more of the initial distance between the upper permanent magnet group and the upper conductor plate, the axial length of the upper conductor plate, the axial length of the upper permanent magnet group, the number of permanent magnets in the upper permanent magnet group, and the permanent magnet arrangement mode parameters in the nonlinear damping unit, so as to adjust the nonlinear damping coefficient generated by the upper conductor plate cutting the upper permanent magnet group on the basis of the basic damping coefficient ; ; Configure the preset horizontal displacement of the single mass block when the upper conductor plate starts to cut the magnetic induction line according to the horizontal extreme displacement of the single mass block , and then determine the preset vertical displacement of the single mass block when the upper conductor plate starts to cut the magnetic induction line ; ; Determine the preset horizontal displacement when the upper part of the single mass block starts to contact the adjusting spring according to the horizontal extreme displacement of the single mass block , and then determine the preset vertical displacement when the upper end face of the single mass block starts to contact the adjusting spring ; .

[0014] The calculation expression of the swing arm length of the single mass block is: Wherein, is the swing arm length of the single mass block, is the vibration frequency of the single mass block, is the acceleration due to gravity, is the frequency of the target mode of the controlled structure, is the ratio between the mass of the single mass block and the modal mass of the target mode of the controlled structure, is the mass of the single mass block, is the modal mass of the target mode of the controlled structure; The damping coefficient of the linear damping unit The calculation expression is: Wherein, is the optimal damping coefficient of the linear damping unit, is the optimal damping ratio of the damping device, is the vibration frequency of the single mass block, is the mass of the single mass block, is the ratio between the mass of the single mass block and the modal mass of the target mode of the controlled structure, is a preset coefficient within the range of (0, 1].

[0015] Compared with the prior art, the advantages of the present invention are as follows: Through a clever structural design, the present invention provides a tuned damper with hierarchical variable damping and variable stiffness, that is, by combining hierarchical linear damping and nonlinear damping, and linear stiffness and nonlinear stiffness to expand the applicability of the damping device, thereby realizing the hierarchical change of the damping coefficient and the stiffness coefficient. That is, when the mass block of the damper has a small amplitude, it presents linear damping, and when it has a large amplitude, it presents nonlinear damping, and then more quickly decays large oscillations to convert to the linear damping section, which effectively improves the stability and practicability of the vibration control of the damper. At the same time, the damping characteristics or the stiffness coefficient can be switched under different working conditions, which not only ensures the stability of the damping coefficient at small amplitudes, but also can provide sufficient energy dissipation capacity under extreme conditions to adapt to conventional load conditions and extreme load conditions.

[0016] The present invention not only combines the advantages of linear damping and nonlinear damping, but also has the advantages of linear stiffness and nonlinear stiffness damping devices, and realizes the independent adjustment function of stiffness and damping in the same damping device. At the limit load, the nonlinear damping unit has broadband energy dissipation characteristics. On the other hand, the stiffness adjustment unit further prevents the single mass block from colliding during extreme swaying, thereby realizing double vibration reduction from two angles of stiffness and damping adjustment, and ensuring the damping and vibration reduction effect.

[0017] The method of the present invention first determines the swing arm length of the single mass block, the optimal damping ratio of the linear damping unit, and the horizontal and vertical extreme displacements of the single mass block according to the mass ratio. Then, the optimal damping coefficient of the linear damping unit determined according to the optimal damping ratio of the linear damping unit is set as the optimal damping coefficient. The initial distance between the upper permanent magnet group and the upper conductor plate, the axial length of the upper conductor plate, the axial length of the upper permanent magnet group, the number of permanent magnets in the upper permanent magnet group, and any one or more of the permanent magnet arrangement parameters in the non-linear damping unit are adjusted according to the horizontal extreme displacement of the single mass block, so as to adjust the non-linear damping coefficient generated by the upper conductor plate cutting the upper permanent magnet group. Thus, the damping device of the present invention can adjust the overall damping coefficient of the device by adjusting the non-linear damping coefficient of the non-linear damping unit on the basis of the optimal damping coefficient of the linear damping unit, and can thus be effectively used for vibration reduction in occasions where the controlled structure vibrates greatly and has a large damping requirement.

[0018] Meanwhile, the present invention configures the horizontal displacement of the single mass block when the upper conductor plate starts to cut the magnetic induction line according to the maximum horizontal displacement value of the controlled structure obtained from the dynamic response analysis of the controlled structure under different loads, and then determines the preset vertical displacement of the single mass block when the upper conductor plate starts to cut the magnetic induction line; the preset horizontal displacement when the upper part of the single mass block starts to contact the adjusting spring is determined according to the horizontal extreme displacement, and then the preset vertical displacement when the upper end face of the single mass block starts to contact the adjusting spring is determined. Thus, the optimal setting parameters of each component in the non-linear damping unit and the stiffness adjusting unit are determined in combination with the actual situation of the controlled structure, so that the optimal configuration can be achieved by matching the structure of the damping device, and the damping and vibration reduction effect of the device can be maximally improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Hereinafter, the present invention will be described in more detail based on embodiments and with reference to the drawings. Among them: Figure 1 is a schematic structural diagram of the hierarchical variable damping and variable stiffness pendulum damping device of the present invention; Figure 2 is an exploded structural diagram of the hierarchical variable damping and variable stiffness pendulum damping device of the present invention; Figure 3 is a simplified structural diagram of the hierarchical variable damping and variable stiffness pendulum damping device of the present invention; Figure 4 is a schematic diagram of the positional relationship between the non-linear damping unit and the single mass block of the present invention; Figure 5 is a displacement diagram of the single mass block of the present invention; Figure 6 is a schematic structural diagram of the lower permanent magnet assembly of the present invention; Figure 7 is a schematic structural diagram of the multi-directional guiding assembly of the present invention; Figure 8 It is a graph showing the variation of the damping coefficient of the damping device of the present invention with the actual horizontal displacement of the single mass block; Figure 9 It is a graph showing the variation of the stiffness coefficient of the damping device of the present invention with the actual horizontal displacement of the single mass block; Figure 10 It is a flowchart of the vibration reduction configuration method of the present invention.

[0020] Each label in the figure represents: 1. Damping mounting bracket; 2. Single mass block; 21. Mass block back plate; 3. Vertical guide; 31. Guide roller; 4. Nonlinear damping unit; 41. Upper permanent magnet group; 42. Upper conductor plate; 5. Stiffness adjustment unit; 51. Adjusting spring; 52. Limiting part; 6. Linear damping unit; 61. Lower permanent magnet assembly; 611. Lower permanent magnet group; 612. Permanent magnet group back plate; 62. Lower conductor assembly; 621. Lower conductor flat plate; 7. Multi-directional guide assembly; 71. Guide rail component; 8. Swing arm; 81. Swing arm mounting ring; 9. Linear damping gap. Detailed implementation manners

[0021] The present invention will be further described in detail below in conjunction with the specification drawings and specific embodiments, but the protection scope of the present invention is not limited thereby.

[0022] Figures 1 to 7 An embodiment of the hierarchical variable damping and variable stiffness pendulum damping device of the present invention is shown, which can be used for vibration suppression of large structures such as bridges. In this embodiment, the hierarchical variable damping and variable stiffness pendulum damping device includes a damping mounting bracket 1, a single mass block 2, a vertical guide 3, a nonlinear damping unit 4, a stiffness adjustment unit 5, and a linear damping unit 6. Among them, the single mass block 2 is swingably mounted on the damping mounting bracket 1 through a swing arm 8; a plurality of vertical guides 3 penetrate through the single mass block 2, and the single mass block 2 can move along the length direction of the vertical guide 3; the nonlinear damping unit 4 and the stiffness adjustment unit 5 are arranged between the single mass block 2 and the vertical guide 3, and the linear damping unit 6 is arranged below the single mass block 2. The linear damping unit 6 includes a lower permanent magnet assembly 61 and a lower conductor assembly 62 that are arranged oppositely with a constant gap. The lower permanent magnet assembly 61 or the lower conductor assembly 62 is horizontally limited and vertically decoupled from the single mass block 2 through the vertical guide 3, that is, when the single mass block 2 swings, the lower permanent magnet assembly 61 or the lower conductor assembly 62 and the single mass block 2 only achieve synchronous horizontal displacement through the vertical guide 3 in the horizontal direction, and the lower permanent magnet assembly 61 or the lower conductor assembly 62 and the single mass block 2 move relatively in the vertical direction. Its layout structure is compact and occupies little space.

[0023] Meanwhile, through ingenious structural design, the present invention provides a tuned damper with graded variable damping and variable stiffness, that is, by combining graded linear damping and nonlinear damping, and linear stiffness and nonlinear stiffness, the applicability of the damping device can be expanded, thereby achieving graded changes in the damping coefficient and stiffness coefficient. That is, for the single-mass block 2 of the damper, linear damping is presented at small amplitudes and nonlinear damping is presented at large amplitudes, and then large oscillations are more rapidly attenuated to convert to the linear damping section, effectively improving the stability and practicality of the damper's vibration control. At the same time, the damping characteristics or stiffness coefficient can be automatically switched under different working conditions, which not only ensures the stability of the damping coefficient at small amplitudes but also provides sufficient energy dissipation capacity under extreme conditions to adapt to both normal load conditions and extreme load conditions.

[0024] When the single-mass block 2 swings to the first critical height, the single-mass block 2 moves to the nonlinear damping unit 4, thereby generating nonlinear eddy current damping. When the single-mass block 2 swings, the gap between the lower permanent magnet assembly 61 and the lower conductor assembly 62 of the linear damping unit 6 remains unchanged. At this time, the linear damping unit 6 always generates linear eddy current damping, and at this time, the damping coefficient is a constant. That is, when the displacement of the single-mass block 2 is small, the damping device only provides linear damping. Linear damping provides a stable damping force at small amplitudes, avoiding the low energy consumption efficiency caused by too small damping force that may be brought by nonlinear damping, thereby reducing the fatigue cycle of the structure.

[0025] When the displacement amplitude of the single-mass block 2 is too large and exceeds the first critical height, the damping coefficient changes nonlinearly (approximately a quadratic parabola) with the increase of the displacement amplitude of the single-mass block 2. At this time, the larger the amplitude of the single-mass block 2, the more the damping coefficient increases exponentially. At this time, the nonlinear damping rapidly attenuates the oscillation at large amplitudes, reducing the number of oscillation cycles, thereby reducing the fatigue damage of the structure caused by large-amplitude oscillations.

[0026] Meanwhile, both the nonlinear damping unit 4 and the linear damping unit 6 cut the magnetic induction line to generate eddy currents, and the eddy currents generate electromagnetic fields with magnetic field polarities opposite to those of their corresponding permanent magnet groups. These two electromagnetic fields with opposite polarities impede each other's movement, generating an eddy current damping effect to present nonlinear damping. The single-mass block 2 generates heat energy through eddy current heating when cutting the magnetic induction line during vertical and horizontal movements. The heat energy is dissipated through conduction by air, etc. Under the action of the eddy current damping effect, the single-mass block 2 moves slower and slower in the vertical and horizontal directions, and the angle becomes smaller and smaller until it stops. The vibration energy is finally converted into heat energy generated by eddy current heating, which can simultaneously achieve the maximum energy consumption density and the optimal control of the stroke of the single-mass block 2, ensuring the damping and vibration reduction effect.

[0027] The stiffness adjustment unit 5 provided between the single mass block 2 and the vertical guide member 3 generates non-linear stiffness when the single mass block 2 swings to the second critical height. The stiffness coefficient of the present invention also changes in a graded manner. When the displacement amplitude of the mass block is less than the second critical height, the stiffness coefficient is approximately a constant, that is, the stiffness coefficient changes little with the displacement amplitude of the single mass block 2; when the displacement amplitude of the single mass block 2 is too large and exceeds the second critical height, the stiffness coefficient changes non-linearly with the increase of the displacement amplitude of the single mass block 2, that is, the larger the amplitude of the single mass block 2, the greater the stiffness coefficient increases in multiples. Thus, while adjusting the frequency, the displacement amplitude of the single mass block 2 is limited, structural overrun is prevented, collisions are avoided, and dangerous amplitude movements of the single mass block 2 are effectively prevented under extreme loads. Therefore, the form of the combination of non-linear stiffness and linear stiffness in the present invention can avoid the unpredictability of robustness to a certain extent while taking into account the control frequency band, and can significantly alleviate the difficulty of robustness analysis and prediction.

[0028] It can be seen that the present invention not only combines the advantages of linear damping and non-linear damping, but also has the advantages of linear stiffness and non-linear stiffness damping devices, and realizes the independent adjustment functions of stiffness and damping in the same damping device. At the limit load, the non-linear damping unit 4 has the characteristics of wide-frequency energy dissipation. On the other hand, the stiffness adjustment unit 5 further prevents the single mass block 2 from colliding during extreme swaying, thereby realizing double vibration reduction from two angles of stiffness and damping adjustment, and ensuring the damping vibration reduction effect.

[0029] As Figure 3 shown, further, a linear damping gap 9 is left between the single mass block 2 and the lower permanent magnet assembly 61. When the single mass block 2 moves from the initial state to when the linear damping gap 9 is 0, the lower permanent magnet assembly 61 and the lower conductor assembly 62 move in parallel to generate linear damping; when the single mass block 2 continues to move upward, the non-linear damping unit 4 generates non-linear damping in the form of eddy currents to achieve graded variable damping through a clever structural design.

[0030] As Figure 6 shown, preferably, the lower permanent magnet assembly 61 includes a lower permanent magnet group 611 and a permanent magnet group back plate 612. The lower permanent magnet group 611 is provided on the bottom end surface of the permanent magnet group back plate 612. The lower permanent magnet group 611 includes a plurality of annular permanent magnets, and the plurality of annular permanent magnets are concentrically arranged. As Figure 3 shown, the upper permanent magnet group 41 includes a plurality of annular permanent magnets, and the plurality of annular permanent magnets are arranged along the axial direction of the vertical guide member 3, which ensures that the non-linear damping unit 4 and the linear damping unit 6 provide completely consistent damping coefficients for the damping device in all vibration directions, and further ensures effective vibration reduction of the device in multiple directions.

[0031] Meanwhile, the lower conductor assembly 62 includes a lower conductor flat plate 621, and the lower conductor flat plate 621 moves relative to the annular permanent magnet when the single mass block 2 swings, generating a linear eddy current damping force.

[0032] As Figure 3 and Figure 4 shown, the nonlinear damping unit 4 includes an upper permanent magnet group 41 and an upper conductor plate 42. Among them, the upper permanent magnet group 41 is arranged at the upper end of the vertical guide 3, and the upper conductor plate 42 is arranged in the through hole of the single mass block 2 passing through the vertical guide 3. The first critical height is the initial distance between the lower end face of the upper permanent magnet group 41 and the upper end face of the upper conductor plate 42, and the first critical height is equal to the linear damping gap 9 in the initial state of the single mass block 2; when the upper conductor plate 42 moves to the upper permanent magnet group 41, that is, when the upper end of the upper conductor plate 42 begins to coincide with the lower end of the upper permanent magnet group 41, the upper conductor plate 42 cuts the magnetic induction line and generates eddy current. In this embodiment, the upper conductor plate 42 is an annular conductor plate, and the annular conductor plate is fixed to the inner wall of the through hole of the single mass block 2.

[0033] In this embodiment, the sum of the linear damping gap 9 in the initial state of the single mass block 2 and the axial length of the upper permanent magnet group 41 is greater than the vertical extreme displacement of the single mass block 2, thereby avoiding the over-limit displacement of the single mass block 2 and ensuring the vibration control effect of the controlled structure.

[0034] In this embodiment, the actual horizontal displacement of the single mass block 2 and the damping coefficient of the damping device satisfy the following relationship: (1) Wherein, is the damping coefficient of the damping device, is the optimal damping coefficient of the linear damping unit, is the nonlinear damping coefficient generated by the upper conductor plate 42 cutting the upper permanent magnet group 41, is the preset horizontal displacement of the single mass block 2 when the upper conductor plate 42 begins to cut the magnetic induction line, is the actual horizontal displacement of the single mass block 2, is the pendulum arm 8 length of the single mass block 2, is the preset vertical displacement of the single mass block 2 when the upper conductor plate 42 begins to cut the magnetic induction line, that is, the first critical height; is the preset axial length of the upper permanent magnet group 41, is the actual vertical displacement of the single mass block 2.

[0035] As Figure 5 and Figure 8 shown, the relationship among the actual vertical displacement of the single mass block 2, the actual horizontal displacement of the single mass block, and the pendulum arm 8 length of the single mass block 2 is: . When , When , at this time, the linear damping unit 6 always generates linear eddy current damping. When , When , at this time, the nonlinear damping unit 4 provides nonlinear damping. At the same time, the linear damping unit 6 always generates linear eddy current damping, thereby generating a nonlinear damping with the damping coefficient doubling as the amplitude increases, ensuring the damping and vibration reduction effect. For example: under normal loads, the linear damping unit 6 can be used to provide linear damping, and the linear damping is more stable; under extreme loads, the damping coefficient provided by the linear damping unit 6 is insufficient, and the vibration response amplitude will exceed the stroke. The nonlinear damping unit 4 can provide greater nonlinear damping to limit the vibration response faster.

[0036] Furthermore, as Figures 1 to 4 shown, the stiffness adjustment unit 5 includes an adjustment spring 51 and a limiting portion 52 that is in limiting cooperation with the adjustment spring 51. Among them, the adjustment spring 51 is provided at the upper end of the vertical guide member 3, and the limiting portion 52 is the upper end surface of the single mass block 2. When the stiffness adjustment unit 5 swings to the second critical height on the single mass block 2, the limiting portion 52 contacts the bottom of the adjustment spring 51 and starts to compress the adjustment spring 51 to generate nonlinear stiffness. At this time, the stiffness coefficient changes nonlinearly with the increase of the displacement amplitude of the single mass block 2, that is, the greater the amplitude of the single mass block 2, the stiffness coefficient of the adjustment spring 51 increases exponentially, thereby changing the frequency . The wider the frequency band, the higher the tolerance of the damper to frequency changes and the stronger the adaptability. At the same time, the combination of linear stiffness and nonlinear stiffness in the present invention can avoid the unpredictability of robustness to a certain extent, reduce the complexity and sensitivity brought by nonlinear design, significantly alleviate the difficulty of robustness analysis and prediction, and thus improve the overall robustness and practicality of the system.

[0037] It can be seen that the adjustment spring 51 of this embodiment can effectively adjust the frequency while limiting the movement range of the single mass block 2. That is, under extreme loads, the adjustment spring 51 can effectively prevent the single mass block 2 from moving with a dangerous amplitude and provide the last protection measure for the controlled structure not to be damaged. Moreover, the adjustment spring 51 has the characteristics of high reliability, low maintenance requirements, and low cost. In this embodiment, the adjustment spring 51 can be set according to actual needs, such as a linear stiffness spring or a progressive stiffness spring. When the adjustment spring 51 is set as a progressive stiffness spring, the stiffness coefficient of the damping device changes unevenly with the compression amount to achieve frequency adjustment.

[0038] The core mechanism of vibration control in the present invention is to dissipate energy through the nonlinear damping unit 4 and the linear damping unit 6 to reduce the vibration amplitude, while the adjusting spring 51 serves as a frequency modulation measure and the ultimate protection measure under extreme loads. The nonlinear damping controls vibration by dynamically adjusting the damping coefficient, while the adjusting spring 51 ensures that the displacement does not exceed the critical threshold. That is, the collaborative use of the nonlinear damping unit 4 and the adjusting spring 51 can take into account the vibration control under normal loads and the structural safety under extreme loads.

[0039] In this embodiment, the actual horizontal displacement of the single mass block 2 and the stiffness coefficient of the damping device satisfy the following relationship: (2) Wherein, is the stiffness coefficient of the damping device, is the optimal stiffness coefficient of the single mass block, is the stiffness coefficient of the adjusting spring 51, is the actual horizontal displacement of the single mass block 2, is the preset horizontal displacement when the upper end surface of the single mass block 2 starts to contact the adjusting spring 51, is the pendulum arm length of the single mass block 2, is the preset vertical displacement when the upper end surface of the single mass block 2 starts to contact the adjusting spring 51, that is, the second critical height; is the preset axial length of the adjusting spring 51.

[0040] As Figure 9 shown, when , , , the stiffness coefficient is approximately a constant, and the stiffness coefficient changes little with the displacement amplitude of the single mass block 2. When , , , the stiffness coefficient increases nonlinearly with the increase of the displacement amplitude of the single mass block 2, that is, the larger the amplitude of the single mass block 2, the greater the stiffness coefficient increases. Preferably, the present invention can further limit the damper stroke by changing the stiffness parameter to avoid collision.

[0041] Preferably, as Figure 1 and Figure 2 shown, the nonlinear damping unit 4 and the stiffness adjustment unit 5 are alternately arranged at intervals along the outer periphery of the single mass block 2. The initial distance between the upper end surface of the single mass block 2 and the lower end of the adjusting spring 51 is the second critical height, and the second critical height is greater than or equal to the first critical height. At this time, the damper mainly relies on nonlinear damping to dissipate energy. The damper is a nonlinear energy well, which has high-efficient vibration absorption and energy dissipation capabilities, as well as the characteristics of wide frequency, passive, and light weight.

[0042] As Figure 7As shown, a multi-directional guiding assembly 7 is provided between the lower permanent magnet assembly 61 and the lower conductor assembly 62. The multi-directional guiding assembly 7 includes two sets of guide rail components 71 that are cross-arranged and relatively slidable. Among them, the lower permanent magnet assembly 61 is fixedly connected to the slider of the upper guide rail component 71 to slide along the slide rail of the guide rail component 71. The lower guide rail component 71 is fixedly installed on the lower conductor assembly 62. At this time, the gap between the lower permanent magnet assembly 61 and the lower conductor assembly 62 remains unchanged, so as to ensure that the linear damping unit 6 always cuts the magnetic induction lines and provides linear damping when the single mass block 2 swings. In this embodiment, the two sets of guide rail components 71 are vertically cross-crossed to realize the swing of the single mass block 2 in two vertical directions.

[0043] Further, a guiding roller 31 is provided between the vertical guiding member 3 of the adjusting spring 51 and the through hole of the single mass block 2 to ensure the effective sliding fit between the single mass block 2 and the vertical guiding member 3 and ensure the smooth and safe swing of the single mass block 2.

[0044] Preferably, mass block back plates 21 are provided on the upper and lower end faces of the single mass block 2, and the single mass block 2 and the mass block back plates 21 are connected by screws for convenient disassembly and installation of components. As Figure 1 shown, the upper end of the swing arm 8 is detachably installed on the damping mounting bracket 1 through a swing arm mounting ring 81, and the lower end of the swing arm 8 is detachably installed on the mass block back plate 21 on the upper end face of the single mass block 2 through a swing arm mounting ring 81.

[0045] In this embodiment, the specific implementation process of the hierarchical variable damping and variable stiffness pendulum damping device is as follows: when the controlled structure vibrates, the single mass block 2 suspended on the damping mounting bracket 1 swings. In the vertical direction, the single mass block 2 moves up and down along with the vertical guiding member 3. In the horizontal direction, the single mass block 2 and the lower permanent magnet group 611 slide in parallel along with the guide rail component 71, and the gap between the lower permanent magnet group 611 and the lower conductor plate 621 remains unchanged. At this time, the damping coefficient of the damping device is constant and presents linear damping. When the single mass block 2 moves vertically along with the vertical guiding member 3 to the first critical height, the upper conductor plate 42 of the single mass block 2 and the upper permanent magnet group 41 installed on the vertical guiding member 3 start to cut the magnetic induction lines and generate eddy current damping, and the damping coefficient is not constant and presents non-linear damping. When the single mass block 2 moves vertically along with the vertical guiding member 3 to the second critical height, the adjusting spring 51 installed on the vertical guiding member 3 can realize multi-level stiffness change. The present invention realizes the vibration control of the damper and improves the energy dissipation efficiency by hierarchical linear damping and non-linear damping, and hierarchical linear stiffness and non-linear stiffness, and passively changes the damping coefficient and stiffness coefficient with the swing amplitude.

[0046] As Figure 10As shown in the figure, for the vibration reduction configuration method of the hierarchical variable-damping and variable-stiffness pendulum damping device as described above in this embodiment, the method of the present invention first determines the swing arm length of the swing arm 8 of the single mass block 2 and the optimal damping ratio of the linear damping unit 6 according to the mass ratio, determines the vertical extreme displacement of the single mass block 2 according to the swing arm length of the swing arm 8 of the single mass block 2 and the horizontal extreme displacement of the single mass block 2. Then, the optimal damping coefficient of the linear damping unit 6 determined according to the optimal damping ratio of the linear damping unit 6 is set as the basic damping coefficient, and any one or more of the initial distance between the upper permanent magnet group 41 and the upper conductor plate 42, the axial length of the upper conductor plate 42, the axial length of the upper permanent magnet group 41, the number of permanent magnets of the upper permanent magnet group 41, and the permanent magnet arrangement mode parameters in the nonlinear damping unit 4 are adjusted according to the horizontal extreme displacement of the single mass block 2, so as to adjust the nonlinear damping coefficient generated by the upper conductor plate 42 cutting the upper permanent magnet group 41 on the basis of the basic damping coefficient, so that the damping device of the present invention can accurately and quickly adjust the nonlinear damping coefficient through the nonlinear damping unit 4 on the basis of the optimal damping coefficient of the linear damping unit 6, thereby realizing the adjustment of the overall damping coefficient of the device, and thus can be applicable to the effective vibration reduction in occasions where the controlled structure vibrates greatly and the damping demand is large.

[0047] At the same time, the present invention configures the preset horizontal displacement of the single mass block 2 when the upper conductor plate 42 starts to cut the magnetic induction line according to the horizontal extreme displacement of the single mass block 2, and then determines the preset vertical displacement of the single mass block 2 when the upper conductor plate 42 starts to cut the magnetic induction line; at the same time, the preset horizontal displacement of the single mass block 2 when the upper part of the single mass block 2 starts to contact the adjustment spring 51 is determined according to the horizontal extreme displacement of the single mass block 2, and then the preset vertical displacement of the single mass block 2 when the upper end surface of the single mass block 2 starts to contact the adjustment spring 51 is determined. Thus, the optimal setting parameters of each component in the nonlinear damping unit 4 and the stiffness adjustment unit 5 are determined in combination with the actual situation of the controlled structure, so that the optimal configuration can be realized by matching the structure of the damping device, and the damping and vibration reduction effect of the device can be maximally improved.

[0048] For example, when the wind turbine is under extreme load conditions, the energy dissipation capacity of the non-linear damping can be enhanced by adjusting the non-linear damping coefficient of the non-linear damping unit 4 first (such as optimizing the number of permanent magnets and the arrangement of permanent magnets in the upper permanent magnet group 41). Through the adjustment of the non-linear damping unit 4, the controlled structure rarely reaches the stroke limit. Even if it does, the residual impact energy will be significantly reduced, thus significantly reducing the dependence on the adjusting spring 51 and the impact load. At the same time, when the vibration displacement inevitably touches the limit, the "soft landing" can be achieved through the progressive stiffness setting of the configured stiffness adjustment unit 5 (adjusting spring 51), rather than a rigid collision. The combined configuration of the non-linear damping unit 4 and the stiffness adjustment unit 5 enables the optimized non-linear damping unit 4 to reduce the burden of the stiffness adjustment unit 5, while the reasonable stiffness adjustment unit 5 provides safety redundancy for the damping system to find the best balance between the stroke limit and the vibration control requirements.

[0049] See Figure 10 , the vibration reduction configuration method of the hierarchical variable damping and variable stiffness pendulum damping device in this embodiment specifically includes: Step 1), according to the mass of the single mass block 2 and the modal mass of the target mode of the controlled structure calculate the mass ratio , according to the mass ratio determine the length of the swing arm 8 of the single mass block 2 and the optimal damping ratio of the linear damping unit 6 .

[0050] Among them, the principle of determining the length of the swing arm 8 of the single mass block 2 can be: according to the mass of the single mass block 2 and the modal mass of the target mode of the controlled structure the ratio between and the frequency of the target mode of the controlled structure calculate the vibration frequency of the single mass block 2 , according to the obtained vibration frequency of the single mass block 2 determine the length of the swing arm 8 of the single mass block 2 。 The length of the swing arm 8 of the single mass block 2 can be calculated and determined according to the following formula : (3) (4) (5) Among them, is the length of the swing arm 8 of the single mass block 2, is the vibration frequency of the single mass block 2, is the acceleration due to gravity, is the frequency of the target mode of the controlled structure, is the ratio between the mass of the single mass block 2 and the modal mass of the target mode of the controlled structure, is the mass of the single mass block 2, is the modal mass of the target mode of the controlled structure.

[0051] The mass of the single mass block 2 can be determined according to the overall bearing capacity regulations of the controlled structure and the local bearing capacity of the installation site, and the installation space of the controlled structure. For example, the mass of the single mass block 2 is set within the bearing capacity range of the controlled structure, and a single mass block 2 that meets the installation requirements is set according to the installation space of the controlled structure. The modal mass of the target mode of the controlled structure can be obtained according to the type of the controlled structure before the damping device is set. The mass of the single mass block 2 and the modal mass of the target mode of the controlled structure The ratio between them can be set according to the energy dissipation requirement. For example, the larger it is, the more energy the damper can absorb and dissipate, and the better the vibration reduction effect. The frequency of the target mode of the controlled structure is the natural vibration frequency of the controlled structure itself.

[0052] In this embodiment, the optimal damping ratio of the linear damping unit 6 can be determined according to the mass ratio and the energy dissipation requirement of the controlled structure. For example, the optimal damping ratio of the linear damping unit 6 can be determined by the fixed-point method. The principle of the fixed-point method is to transform the sequence recurrence formula into the form of a geometric sequence or an arithmetic sequence, so as to simplify the solution of the problem, and it can be applied to the occasion with low energy dissipation requirement of the controlled structure to quickly obtain the optimal damping ratio of the linear damping unit 6 .

[0053] The optimal damping ratio of the linear damping unit 6 is calculated and confirmed by the fixed-point method The preferred formula is: (6) Wherein, is the optimal damping ratio of the linear damping unit 6, is a preset coefficient within the range of (0, 1].

[0054] When the above formula is satisfied, it corresponds to calculating the optimal damping ratio of the linear damping unit 6 when using the traditional fixed-point method . Preferably, the optimal damping ratio of the linear damping unit 6 can also be determined by the improved fixed-point method. For example, , that is, according to to determine the optimal damping ratio , the convergence speed and accuracy of the iteration can be further improved.

[0055] More preferably, the optimal damping ratio of the linear damping unit 6 can also be determined by the method of the maximum modal damping ratio. For example, , according to to determine the optimal damping ratio , further improve the optimal damping ratio of the linear damping unit 6 accuracy, thereby further improving the energy dissipation capacity of the structure. It can be seen that when confirming the optimal damping ratio of the linear damping unit 6 , the preset coefficient is selected to be large, the accuracy of the optimal damping ratio of the linear damping unit 6 is higher, and the damping and vibration reduction ability of the device is better.

[0056] In other embodiments, the optimal damping ratio of the linear damping unit 6 can also be determined in other ways according to requirements.

[0057] In this embodiment, the horizontal extreme displacement of the single mass block 2 is measured , according to the swing arm 7 length of the single mass block 2 and the horizontal extreme displacement of the single mass block 2 to determine the vertical extreme displacement of the single mass block 2 .

[0058] The stroke limit value of the single mass block 2 includes the horizontal extreme displacement of the single mass block 2 and the vertical extreme displacement value. The horizontal extreme displacement can be determined according to the actual installation space inside the controlled structure. For example, when the single mass block 2 swings horizontally to the extreme position without touching the internal components of the controlled structure as the standard, or the safety distance between the extreme swing position of the single mass block 2 and the inside of the controlled structure can be preset according to the actual situation.

[0059] More preferably, the horizontal extreme displacement of the single mass block 2 is obtained according to the response analysis of the controlled structure under different loads . Specifically, the horizontal displacement of the controlled structure under different loads is obtained through the response analysis, and the maximum horizontal displacement under different loads is determined as the horizontal extreme displacement of the single mass block 2.

[0060] After that, the vertical extreme displacement of the single mass block 2 can be determined according to the horizontal extreme displacement of the single mass block 2 , the swing arm 8 length of the single mass block 2 according to the following formula to determine the vertical extreme displacement of the single mass block 2 : (7) Preferably, in addition to determining the above parameters, other parameters can also be set. For example, the initial stiffness of the damping device can also be determined . The initial stiffness of the damping device can be determined according to the following formula: (8) In this embodiment, the length of the swing arm 8 of the single mass block 2 is much larger than the actual horizontal displacement of the single mass block 2, that is , at this time, the initial stiffness of the damping device is the simple pendulum stiffness, and can be determined according to the length of the swing arm 8 of the single mass block 2 obtained , the mass of the single mass block 2 to determine the initial stiffness of the damping device according to the following formula : (9) Step 2), according to the optimal damping ratio of the linear damping unit 6, calculate the optimal damping coefficient of the linear damping unit 6, and set the optimal damping coefficient of the linear damping unit 6 as the basic damping coefficient; adjust any one or more of the parameters of the initial distance between the upper permanent magnet group 41 and the upper conductor plate 42, the axial length of the upper conductor plate 42, the axial length of the upper permanent magnet group 41, the number of permanent magnets of the upper permanent magnet group 41, and the permanent magnet arrangement mode in the nonlinear damping unit 4, so as to adjust the nonlinear damping coefficient generated by the upper conductor plate 42 cutting the upper permanent magnet group 41 on the basis of the basic damping coefficient . The damping device of the present invention can accurately and quickly adjust the nonlinear damping coefficient through the nonlinear damping unit 4 on the basis of the basic damping coefficient of the linear damping unit 6, so as to realize the adjustment of the overall damping coefficient of the device, and thus can be effectively used for vibration reduction in occasions where the controlled structure vibrates greatly and has a large damping requirement

[0061] Furthermore, the optimal damping coefficient of the linear damping unit 6 can be determined according to the optimal damping ratio of the linear damping unit 6, the vibration frequency of the single mass block 2, and the mass of the single mass block 2, so as to quickly obtain an accurate optimal damping coefficient of the linear damping unit 6 according to the actual situation of the single mass block 2, meet the damping and vibration reduction requirements of different controlled structures, and thus provide an accurate optimal damping coefficient of the damping device of the present invention (10) In this embodiment, the mass of the single mass block 2 is a fixed value, and the vibration frequency of the single mass block 2 and the optimal damping ratio of the linear damping unit 6 can be determined by Equations (3) and (6).

[0062] Preferably, the non-linear damping coefficient of the non-linear damping unit 4 can be set according to the needs of the actual project. For example, on the basis of the optimal damping coefficient of the linear damping unit 6 and according to the horizontal extreme displacement of the single mass block 2 the non-linear damping coefficient is set. After that, the non-linear damping coefficient of the non-linear damping unit 4 can be adjusted to the optimal value by adjusting any one or more of the initial distance between the upper permanent magnet group 41 and the upper conductor plate 42, the axial length of the upper conductor plate 42, the axial dimension of the upper permanent magnet group 41, the number of permanent magnets in the upper permanent magnet group 41, the permanent magnet arrangement method, and the permanent magnet material to the optimal value.

[0063] In step 3), the preset horizontal displacement of the single mass block 2 when the upper conductor plate 42 starts to cut the magnetic induction line can be configured according to the horizontal extreme displacement of the single mass block 2 , and then the preset vertical displacement of the single mass block 2 when the upper conductor plate 42 starts to cut the magnetic induction line can be determined .

[0064] The preset horizontal displacement of the single mass block 2 when the upper conductor plate 42 starts to cut the magnetic induction line can be set near or slightly higher than the horizontal extreme displacement of the single mass block 2 , that is, the horizontal extreme displacement of the single mass block 2 is set to fall within the linear damping zone of the damping device (that is ), so as to ensure that the behavior of the damping device is closer to the ideal linear tuned mass damper under the normal operating conditions of the controlled structure (such as a wind turbine), so as to most effectively suppress the steady-state vibration of a specific frequency or the conventional vibration caused by continuous wind loads.

[0065] Determine After that, when the horizontal displacement of the single mass block 2 reaches , at this time, the vertical displacement of the single mass block 2 is , so that the single mass block 2 can be determined according to Equation , where , in the formula is ​​, For .

[0066] Furthermore, according to the requirements of the magnitude of the non-linear damping coefficient and considering the limitation of the vertical space set the preset axial length of the upper permanent magnet group 41 . Thus, in the face of extreme environments, ensure the optimal damping coefficient of the linear damping unit 6 and the non-linear damping coefficient of the linear damping unit 6 The combined damping provided meets , so that the controlled structure can effectively reduce vibration in extreme environments.

[0067] In this embodiment, the preset horizontal displacement when the upper part of the single mass block 2 starts to contact the adjusting spring 51 can also be determined according to the horizontal extreme displacement of the single mass block 2 . Thus, according to the above steps, the preset vertical displacement when the upper part of the single mass block 2 starts to cut the magnetic induction line on the upper conductor plate 42 and the preset horizontal displacement when the upper part of the single mass block 2 starts to contact the adjusting spring 51 can be determined respectively . and the preset horizontal displacement when the upper part of the single mass block 2 starts to contact the adjusting spring 51 .

[0068] Specifically, for the preset horizontal displacement when the upper part of the single mass block 2 starts to contact the adjusting spring 51 , satisfies , so that before the single mass block 2 touches the physical limit part 52 of the damping device (hard stop), the adjusting spring 51 is activated to provide "soft" buffering and avoid the impact and potential damage caused by rigid collision. Furthermore it can cooperate with the mass, stiffness, and non-linear damping of the damping device to ensure that after the adjusting spring 51 is triggered, the entire system can effectively dissipate energy and control the displacement of the controlled structure within a safe range. Preferably .

[0069] According to the preset horizontal displacement further determine the preset vertical displacement when the upper end surface of the single mass block 2 starts to contact the adjusting spring 51 . That is, when it is determined , when the horizontal displacement of the single mass block 2 reaches , at this time, the vertical displacement of the single mass block 2 is , so that it can be determined according to Equation and , in the formula is , is 。

[0070] Further, adjust the axial length of the adjusting spring 51 according to the limitation of the vertical space set to ensure 。When facing extreme environments, adjust the axial length of the adjusting spring 51 can provide sufficient reaction force to effectively limit the movement of the damping device, so that in extreme environments, the optimal damping coefficient of the linear damping unit 6 and the non-linear damping coefficient of the linear damping unit 6 while providing damping, further prevent the single-mass block 2 from generating dangerous amplitude movements under extreme loads by adjusting the spring 51. The exact value of the axial length of the adjusting spring 51 can be finally determined and optimized through system modeling, dynamic simulation, and response analysis of the wind turbine under various working conditions (including extreme conditions).

[0071] The present invention does not limit the specific sequential relationship of the steps, and in practice, it can also be executed in other orders. For example, after measuring the horizontal extreme displacement of the single-mass block in step 1) it is also possible to synchronously execute and determine the preset horizontal displacement of the single-mass block in step 3) and the preset vertical displacement , as well as the pre-preset horizontal displacement of the single-mass block 2 and the preset vertical displacement 。

[0072] Figure 8 and Figure 9 show the variation curves of the damping coefficient and stiffness coefficient of the damping device in the specific installation embodiment with the actual horizontal displacement of the single-mass block 2. Specifically: Figure 8 is the variation curve of the damping coefficient of the damping device obtained in the specific embodiment with the actual horizontal displacement of the single-mass block 2. It can be seen that when is the case, , at this time, the linear damping unit 6 always generates linear eddy current damping. When is the case, the non-linear damping unit 4 provides non-linear damping. At the same time, the linear damping unit 6 always generates linear eddy current damping, thereby generating non-linear damping with the damping coefficient doubling as the amplitude increases. Specifically, the damping coefficient of the damping device satisfies 。

[0073] Figure 9 is the variation curve of the stiffness coefficient of the damping device obtained in the specific embodiment with the actual horizontal displacement Variation curve graph. It can be seen that when At this time, , the stiffness coefficient is approximately a constant, and the change of the stiffness coefficient with the displacement amplitude of the single mass block 2 is small. When At this time, the stiffness coefficient increases non-linearly with the increase of the displacement amplitude of the single mass block 2, that is, the larger the amplitude of the single mass block 2, the more the stiffness coefficient increases in multiples. Specifically, the damping coefficient of the damping device satisfies .

[0074] It can be seen that the present invention realizes double vibration reduction from the two aspects of stiffness and damping adjustment through the combination of the non-linear damping unit 4 and the stiffness adjustment unit 5 at the limit load, ensures the damping vibration reduction effect, and effectively improves the safety and service life of the overall structure of the controlled structure.

[0075] Although the present invention has been described with reference to the preferred embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A hierarchical variable damping and variable stiffness pendulum damping device, characterized in that, It includes a damping mounting bracket, a single mass block swingably mounted on the damping mounting bracket, a plurality of vertical guiding members passing through the single mass block, a non-linear damping unit and a stiffness adjustment unit provided between the single mass block and the vertical guiding members, and a linear damping unit provided below the single mass block. Among them, the linear damping unit includes a lower permanent magnet assembly and a lower conductor assembly arranged oppositely with an unchanged gap. The lower permanent magnet assembly or the lower conductor assembly is horizontally limited and vertically decoupled from the single mass block through the vertical guiding member. The non-linear damping unit generates non-linear eddy current damping when the single mass block swings to a first critical height, and the linear damping unit always generates linear eddy current damping when the single mass block swings. The stiffness adjustment unit generates non-linear stiffness when the single mass block swings to a second critical height.

2. The pendulum damping device with graded variable damping and variable stiffness according to claim 1, characterized in that A linear damping gap is left between the single mass block and the lower permanent magnet assembly. When the single mass block moves from the initial state to the linear damping gap being 0, the lower permanent magnet assembly and the lower conductor assembly move parallel to generate linear damping. When the single mass block continues to move upward, the non-linear damping unit generates non-linear eddy current damping.

3. The stepped variable damping and variable stiffness pendulum damping device according to claim 2, wherein, The non-linear damping unit includes an upper permanent magnet group and an upper conductor plate. The upper permanent magnet group is provided at the upper end of the vertical guiding member, and the upper conductor plate is provided in the through hole of the single mass block passing through the vertical guiding member. The upper conductor plate cuts the magnetic induction line to generate eddy current when moving to the upper permanent magnet group. The first critical height is the initial distance between the lower end face of the upper permanent magnet group and the upper end face of the upper conductor plate. The first critical height is equal to the linear damping gap in the initial state of the single mass block. The sum of the linear damping gap in the initial state of the single mass block and the axial length of the upper permanent magnet group is greater than the vertical extreme displacement of the single mass block.

4. The hierarchical variable-damping and variable-stiffness pendulum damping device according to claim 3, wherein The actual horizontal displacement of the single mass block and the damping coefficient of the damping device satisfy the following relationship: Among them, is the damping coefficient of the damping device, is the optimal damping coefficient of the linear damping unit, is the non-linear damping coefficient generated by the upper conductor plate cutting the upper permanent magnet group, is the preset horizontal displacement of the single mass block when the upper conductor plate starts to cut the magnetic induction line, is the actual horizontal displacement of the single mass block, is the swing arm length of the single mass block, is the preset vertical displacement of the single mass block when the upper conductor plate starts to cut the magnetic induction line, is the preset axial length of the upper permanent magnet group, is the actual vertical displacement of the single mass block.

5. The step-variable damping and variable stiffness pendulum damping device according to any one of claims 1 to 4, characterized in that The stiffness adjustment unit includes an adjustment spring and a limiting portion that is in limiting cooperation with the adjustment spring. The adjustment spring is provided at the upper end of the vertical guiding member, and the limiting portion is the upper end face of the single mass block. The second critical height is the initial distance between the lower end face of the adjustment spring and the upper end face of the single mass block. When the single mass block swings to the second critical height, the upper end face of the single mass block contacts the adjustment spring to generate non-linear stiffness. The sum of the second critical height and the axial length of the adjustment spring is greater than the vertical extreme displacement of the single mass block.

6. The pendulum damping device with graded variable damping and variable stiffness according to claim 5, characterized in that, The actual horizontal displacement of the single mass block and the stiffness coefficient of the damping device satisfy the following relationship: wherein, is the stiffness coefficient of the damping device, is the optimal stiffness coefficient of the single mass block, is the stiffness coefficient of the adjusting spring, is the actual horizontal displacement of the single mass block, is the preset horizontal displacement when the upper end surface of the single mass block starts to contact the adjusting spring, is the swing arm length of the single mass block, is the preset vertical displacement when the upper end surface of the single mass block starts to contact the adjusting spring, is the preset axial length of the adjusting spring, is the actual vertical displacement of the single mass block.

7. The step-variable damping and variable stiffness pendulum damping device according to any one of claims 1 to 4, characterized in that, The non-linear damping unit and the stiffness adjustment unit are alternately arranged at intervals along the outer periphery of the single mass block. The second critical height is greater than or equal to the first critical height.

8. The hierarchical variable-damping and variable-stiffness pendulum damping device according to any one of claims 1 to 4, characterized in that, A multi-directional guiding component for ensuring the invariance of the gap between the lower permanent magnet component and the lower conductor component is provided therebetween. The multi-directional guiding component includes two sets of guide rail components which are cross-arranged and relatively slidable. The lower permanent magnet component is slidably connected to the upper guide rail component, and the lower guide rail component is fixedly installed on the lower conductor component.

9. A vibration reduction configuration method for the hierarchical variable damping and variable stiffness pendulum damping device according to any one of claims 1 to 8, characterized in that, Comprising: According to the mass of the single mass block , the modal mass of the target mode of the controlled structure calculate the mass ratio , and according to the mass ratio determine the swing arm length of the single mass block , the optimal damping ratio of the linear damping unit ; Measure the horizontal extreme displacement of the single mass block , and determine the vertical extreme displacement of the single mass block based on the swing arm length of the single mass block and the horizontal extreme displacement of the single mass block ; According to the optimal damping ratio of the linear damping unit Calculate the optimal damping coefficient of the linear damping unit , and set the optimal damping coefficient of the linear damping unit as the basic damping coefficient; adjust any one or more of the parameters of the initial distance between the upper permanent magnet group and the upper conductor plate, the axial length of the upper conductor plate, the axial length of the upper permanent magnet group, the number of permanent magnets in the upper permanent magnet group, and the permanent magnet arrangement method in the non-linear damping unit, so as to adjust the non-linear damping coefficient generated by the upper conductor plate cutting the upper permanent magnet group on the basis of the basic damping coefficient ; According to the horizontal extreme displacement of the single mass block Configure the preset horizontal displacement of the single mass block when the upper conductor plate starts to cut the magnetic induction line , and then determine the preset vertical displacement of the single mass block when the upper conductor plate starts to cut the magnetic induction line ; According to the horizontal extreme displacement of the single mass block Determine the preset horizontal displacement when the upper part of the single mass block starts to contact the adjusting spring , and further determine the preset vertical displacement when the upper end face of the single mass block starts to contact the adjusting spring .

10. The vibration damping configuration method according to claim 9, characterized in that The swing arm length of the single mass block The calculation expression is: Among them, is the swing arm length of the single mass block, is the vibration frequency of the single mass block, is the acceleration due to gravity, is the frequency of the target mode of the controlled structure, is the ratio between the mass of the single mass block and the modal mass of the target mode of the controlled structure, is the mass of the single mass block, is the modal mass of the target mode of the controlled structure; The damping coefficient of the linear damping unit has the following calculation expression: Among them, is the optimal damping coefficient of the linear damping unit, is the optimal damping ratio of the damping device, is the vibration frequency of the single mass block, is the mass of the single mass block, is the ratio between the mass of the single mass block and the modal mass of the target mode of the controlled structure, is a preset coefficient within the range of (0, 1].

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