A primary structure displacement amplification type tuned negative stiffness inertance vibration absorption system

Abstract

The application belongs to the technical field of vibration control, and particularly relates to a main structure displacement amplification type tuned negative stiffness inertial mass dynamic vibration absorbing system. The system comprises a bottom plate, a core transmission member, a positive stiffness spring mechanism, a gear amplification mechanism, a negative stiffness device, an inertial mass device driven to rotate by the movement of the core transmission member to generate an equivalent tuned mass, and an eddy current damping device. The gear amplification mechanism amplifies the initial displacement input by the external main structure, overcoming the defects of the traditional shock absorber, such as difficulty in triggering and insufficient work under low frequency or slight vibration; not only the natural frequency of the coupled structure is reduced by the negative stiffness effect to broaden the vibration reduction frequency band, but also more energy is dissipated in unit time and a huge equivalent tuned mass is generated, so that the destructive large displacement of the base isolation layer in strong earthquakes is extremely efficiently inhibited without significantly increasing the structure acceleration, and the seismic safety of the building is comprehensively improved.

Description

[Technical Field] This application belongs to the field of vibration control technology, specifically relating to a tuned negative stiffness inertial capacitance dynamic vibration absorption system for main structure displacement amplification. [Background Technology] For key earthquake monitoring and defense zones or critical buildings with special functions that cannot be interrupted, seismic isolation layers are installed to block the transmission of seismic waves to the upper structure. However, traditional seismic isolation techniques often produce excessive relative displacement under strong earthquakes and near-field pulse earthquakes. This not only threatens the shear safety of the supports but may also lead to collision damage to the foundation structure. To further optimize the seismic isolation effect, introducing negative stiffness elements can reduce the system frequency and broaden the damping bandwidth; introducing inertial capacitance devices can generate a large equivalent tuned mass with a small physical mass; and introducing damping elements can handle energy dissipation. However, these methods often fail to fully utilize their performance under small vibrations or low frequencies due to insufficient displacement. Therefore, developing a vibration absorption system that can amplify the displacement response and synergistically utilize the performance of negative stiffness and inertial capacitance is of significant engineering importance. [Summary of the Invention] To address the problems in existing technologies where the base isolation layer is prone to excessive and destructive displacement under strong earthquakes, and where traditional damping components are difficult to effectively trigger and fully dissipate energy under small amplitudes, this application provides a tuned negative stiffness inertial capacitance dynamic vibration absorption system with amplified main structure displacement.

[0001] This application is achieved through the following technical solution: A tuned negative stiffness inertial-capacitive dynamic vibration absorption system with main structure displacement amplification includes a base plate, a core transmission component slidably disposed on the base plate, an elastic mechanism for connecting to and receiving the displacement of the external main structure, a gear amplification mechanism connected between the elastic mechanism and the core transmission component for amplifying the received displacement and transmitting it to the core transmission component, a negative stiffness device symmetrically arranged on both sides of the core transmission component and cooperating with the core transmission component to generate a negative stiffness effect, an inertial-capacitive device driven to rotate by the motion of the core transmission component to generate an equivalent tuned mass, and an eddy current damping device integrated with the inertial-capacitive device and used to generate eddy current damping when the inertial-capacitive device is in operation.

[0002] As described above, a tuned negative stiffness inertial capacitance dynamic vibration absorption system with main structure displacement amplification includes a core transmission component comprising an annular portion located in the middle and used to cooperate with the negative stiffness device, and a first rack and a second rack located on the upper and lower sides of the annular portion, respectively. The first rack is used to cooperate with the inertial capacitance device, and the second rack is used to cooperate with the gear amplification mechanism.

[0003] As described above, a tuned negative stiffness inertial capacitance dynamic vibration absorption system with main structure displacement amplification includes an elastic mechanism comprising a sliding plate, a gear transmission component, and an elastic element disposed between the sliding plate and the gear transmission component. An external displacement force can drive the sliding plate, thereby compressing the elastic element and causing the gear transmission component to move.

[0004] The above-described main structure displacement amplification tuned negative stiffness inertial capacitance dynamic vibration absorption system further includes a pad plate disposed on the base plate, and multiple first rollers are arranged on the left and right sides of the lower end of the sliding plate, and the sliding plate slides on the pad plate through the first rollers.

[0005] As described above, a tuned negative stiffness inertial capacitance dynamic vibration absorption system with main structure displacement amplification includes a gear amplification mechanism that meshes with the gear transmission component and a transmission gear that meshes with the second rack. When the transmission pinion rotates under the drive of the gear transmission component, it drives the transmission gear to rotate synchronously, thereby amplifying the input displacement and transmitting it to the core transmission component.

[0006] As described above, in a main structure displacement amplification tuned negative stiffness inertial capacitance dynamic vibration absorption system, a rotating bearing is provided at the lower part of the gear amplification mechanism, and a positioning column is provided on the base plate for mounting and positioning the rotating bearing.

[0007] As described above, a tuned negative stiffness inertial capacitance dynamic vibration absorption system for main structure displacement amplification includes two symmetrically arranged negative stiffness mechanisms. Each negative stiffness mechanism includes an annular cylinder connected to the side of the pad plate via a sliding bearing. A pre-compression spring is provided inside the annular cylinder. A roller is installed on the head of the annular cylinder facing the core transmission component. The roller presses against the annular portion of the core transmission component under the action of the pre-compression spring. When the core transmission component moves, the horizontal spring compression force is converted into a vertical component force to assist the movement of the core transmission component.

[0008] As described above, a tuned negative stiffness inertial capacitance dynamic vibration absorption system with main structure displacement amplification is provided inside the pad plate, which is provided to slide through the side of the annular cylinder and engage with the inner wall of the annular cylinder. The pre-compression spring is provided between the buckle and the negative stiffness mechanism to ensure the compression state of the spring. The negative stiffness mechanism is provided with second rollers on both sides to reduce friction with the base plate.

[0009] As described above, a tuned negative stiffness inertial capacitance dynamic vibration absorption system with main structure displacement amplification includes an inertial capacitance device comprising a driven pinion rotatably connected to the base plate and meshing with the first rack, a driven large gear coaxially connected to the driven pinion, a flywheel rotatably connected to the base plate, and a flywheel gear disk coaxially connected to the flywheel and meshing with the driven large gear. The first rack drives the driven large gear to rotate, thereby driving the flywheel to rotate at high speed to generate equivalent mass.

[0010] As described above, a tuned negative stiffness inertial capacitance dynamic vibration absorption system with main structure displacement amplification includes an eddy current damping device comprising an annular copper sheet disposed on the flywheel and magnet groups located on the upper and lower sides of the annular copper sheet; the annular copper sheet follows the rotation of the flywheel and moves within the magnetic field arranged by the magnet groups, cutting magnetic field lines, thereby generating eddy current damping.

[0011] Compared with the prior art, this application has the following advantages: 1. The gear amplification mechanism amplifies the initial displacement input from the external main structure, overcoming the shortcomings of traditional shock absorbers, such as difficulty in triggering and insufficient work under low-frequency or small vibrations. At the same time, the amplified displacement synchronously drives the negative stiffness device, inertial capacitance device, and eddy current damping device through the core transmission component. This not only reduces the natural frequency of the coupled structure by utilizing the negative stiffness effect to broaden the vibration reduction frequency band, but also causes the flywheel and damping elements to generate greater relative motion speed, dissipating more energy per unit time and generating a huge equivalent tuned mass. Ultimately, without significantly increasing the structural acceleration, it extremely efficiently suppresses the destructive large displacement that the base isolation layer is prone to generate in strong earthquakes, comprehensively improving the seismic safety of the building.

[0012] 2. By using symmetrically arranged negative stiffness devices, the natural frequency of the coupled structure is reduced, making it easier for the structural system to match the dominant frequency of external vibrations such as earthquakes. This effectively suppresses the resonance peak of the main structure, broadens the effective vibration reduction frequency range of the system, and further assists the movement of the core transmission components, thereby enhancing the overall vibration reduction and energy dissipation effect.

[0013] 3. The system adopts a highly symmetrical structural layout, including a negative stiffness device, flywheel, eddy current damping, etc., and multiple sets of bearings and rollers are widely configured inside and on the contact surfaces of various rolling and sliding elements. This minimizes the adverse effects of mechanical friction on the internal energy transfer and dissipation of the device, ensuring the accuracy of response and the long-term stability of structural operation. [Attached Image Description] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a three-dimensional perspective view of an embodiment of this application; Figure 2 yes Figure 1 Top view; Figure 3 yes Figure 1 Exploded view; Figure 4 This is a schematic diagram of the elastic mechanism in the embodiments of this application; Figure 5 This is a schematic diagram of the gear amplification mechanism in an embodiment of this application; Figure 6 This is a schematic diagram of the negative stiffness device in the embodiments of this application; Figure 7 This is a schematic diagram of the inertial capacitance device and the eddy current damping device of this application; Figure 8 This is a force analysis diagram of the negative stiffness mechanism and the circular part; Figure 9 This is a simplified model diagram of the force on a negative stiffness mechanism; Figure 10 This is a graph showing the effect of different spring stiffness ratios on the profile. Figure 11 This is a graph showing the effect of different spring pre-compression amounts on the contour line. Figure 12 It is a structural dynamics model in which the device is placed on a single-degree-of-freedom structure.

Detailed Implementation Methods

[0015] Please see Figures 1 to 12A tuned negative stiffness inertial-capacitive dynamic vibration absorption system with main structure displacement amplification includes a base plate 1, a core transmission component 2 slidably disposed on the base plate 1, an elastic mechanism 3 for connecting to and receiving the displacement of the external main structure, a gear amplification mechanism 4 connected between the elastic mechanism 3 and the core transmission component 2 for amplifying the received displacement and transmitting it to the core transmission component 2, a negative stiffness device 5 symmetrically arranged on both sides of the core transmission component 2 and cooperating with the core transmission component 2 to generate a negative stiffness effect, an inertial-capacitive device 6 driven to rotate by the motion of the core transmission component 2 to generate an equivalent tuned mass, and an eddy current damping device 7 integrated with the inertial-capacitive device 6 and used to generate eddy current damping when the inertial-capacitive device 6 is in operation.

[0016] In this embodiment, the working principle is as follows: When the external main structure, for example, an equivalent single-degree-of-freedom frame structure with a main structure mass of 23.8 kg, undergoes horizontal displacement under strong external excitation such as an earthquake, the displacement is first received by the elastic mechanism 3. Here, a compression spring with a stiffness coefficient of 1779.44 N / m can be preferably used for flexible buffering and force transmission. Subsequently, the displacement is transmitted to the gear amplification mechanism 4. Through a specific setting of the gear transmission ratio, for example, setting the structural displacement amplification ratio to L=2, the originally small structural displacement is amplified many times and directly transmitted to the core transmission component 2 that slides linearly on the base plate 1. The large-stroke reciprocating motion of the core transmission component 2 will synchronously and efficiently trigger the negative stiffness device 5 symmetrically arranged on both sides and the inertia capacity device 6 at the rear end. In actual engineering design, the negative stiffness device 5 can use a circular cam profile with a maximum diameter of 0.12 m and a pre-compression spring with a pre-compression amount of 0.06 m to accurately output the optimal system negative stiffness of -46.27 N / m to the core transmission component 2 (corresponding to the single-sided mechanism generating - With a stiffness value of 23.135 N / m, it provides an auxiliary thrust consistent with the system's motion direction during low-frequency vibrations, directly reducing the natural frequency of the coupled structure to broaden the vibration reduction frequency band. Simultaneously, the inertial capacitance device 6, through the meshing of gears and racks, converts the linear translational motion of the core transmission component 2 into the high-speed rotational motion of the internal flywheel. Based on the principle that the system's rotational kinetic energy is equal to its equivalent translational kinetic energy, and under the minimal physical conditions of a flywheel radius r = 0.03 m and a single-sided flywheel disk mass of only 0.1225 kg, This allows for the generation of a massive equivalent tuned mass of b=2.38kg when the inertia-to-capacity ratio is 0.1, achieving a super-strong mechanical amplification factor of nearly 10 times the physical mass. During the high-speed rotation of the flywheel, the annular copper sheet in the integrated eddy current damping device 7 will cut magnetic field lines in a strong magnetic field established by a magnet group with a magnetic induction intensity of, for example, B=1.2T, thereby generating a non-contact system-optimal eddy current damping of 30.72N·s / m (corresponding to a single-sided single-plane damping coefficient of 7.68N·s / m). The core transmission component 2, combined with the stroke amplification effect of the gear amplification mechanism 4, breaks the deadlock of traditional shock absorbers being unable to start vibrating under weak vibrations. It substantially increases the relative deformation and movement speed of the internal components of the eddy current damping device 7 and the inertial capacitance device 6 by several times, enabling the damping element to dissipate a considerable amount of seismic energy per unit time. At the same time, by utilizing the huge inertial force induced by the tuning of a small solid mass, it effectively suppresses the back-and-forth sway amplitude of the building foundation without significantly increasing the acceleration of the main structure itself. It fundamentally and perfectly solves the technical pain point that traditional foundation isolation layers are prone to excessive destructive relative displacement under strong earthquakes or near-field pulse earthquakes.

[0017] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, the core transmission component 2 includes an annular portion 21 located in the middle and used to cooperate with the negative stiffness device 5, and a first rack 22 and a second rack 23 located on the upper and lower sides of the annular portion 21, respectively. The first rack 22 is used to cooperate with the inertia device 6, and the second rack 23 is used to cooperate with the gear amplification mechanism 4.

[0018] In this embodiment, the core transmission component 2 adopts a highly integrated three-segment rigid symmetrical structure design. Its working principle is as follows: when the system is under external excitation, the second rack 23 and the first rack 22 located on the upper and lower sides of the core transmission component 2, respectively, and the annular portion 21 located in the middle, simultaneously play the core role of power transmission and motion mode conversion hub. The bottom second rack 23 is used to precisely receive the power input from the gear amplification mechanism 4, and under optimal conditions such as setting the gear transmission amplification ratio to L=2, it almost effortlessly and doubly converts the small initial displacement of the main structure into a linear large-stroke translational motion of the core transmission component 2. With the large-amplitude translational motion of the core transmission component 2 on the base plate, its centrally located annular portion 21, in optimal engineering design... The cam can be a circular solid profile with a maximum diameter of 0.12m, which moves up and down synchronously. The outer profile of the cam directly pushes the rollers in the negative stiffness devices 5 on both sides, thereby squeezing the pre-compression spring inside (for example, a spring with a set stiffness value of 23.135N / m and an initial spring pre-compression of 0.06m). This cleverly and seamlessly converts the potential energy of the spring in the horizontal direction into a vertical component force in line with the movement direction of the core transmission component 2, thereby providing the required negative stiffness auxiliary thrust. At the same time, the first rack 22, which moves linearly at the top synchronously, meshes tightly with the driven pinion of the inertial capacity device 6, converting the large linear displacement of the core transmission component 2 into the high-speed rotation of the flywheel system without lag, thereby outputting a huge equivalent tuned mass. It greatly simplifies the complex transmission links or intermediate conversion mechanisms that were originally required inside the vibration absorber, effectively eliminating the mechanical backlash and mechanical response lag caused by multi-stage flexible transmission. Under the premise of minimal structure, it ensures the absolute synchronous response of displacement amplification input, negative stiffness effect excitation and inertial capacitance damping high-frequency tuning output in the time domain, as well as the balanced force distribution in the spatial domain, which greatly improves the mechanical utilization efficiency and long-term operational stability of the system.

[0019] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, the elastic mechanism 3 includes a sliding plate 31, a gear transmission member 32, and an elastic member 33 disposed between the sliding plate 31 and the gear transmission member 32. An external displacement force can drive the sliding plate 31, thereby compressing the elastic member 33 to drive the gear transmission member 32 to move.

[0020] In this embodiment, when the external main structure (e.g., a simplified model of a multi-degree-of-freedom frame structure with an equivalent mass of 23.8 kg) experiences horizontal displacement due to dynamic loads such as earthquakes, this displacement force directly acts on and drives the sliding plate 31 to slide horizontally. The displacement of the sliding plate 31 forcibly compresses the elastic element 33 located between it and the gear transmission component 32. During this process, the elastic element 33 (a compression spring with a stiffness coefficient of 1779.44 N / m can be precisely selected under optimal design conditions) undergoes elastic deformation and accumulates potential energy, which is then converted into a flexible driving force. This force smoothly pushes and pulls the gear transmission component 32 to perform synchronous linear motion for subsequent amplification mechanisms. Transmitting power; Compared with the rigid direct connection damping structure in the prior art, this flexible transmission hub, which is composed of sliding plate 31, elastic element 33 and gear transmission element 32 connected in series, can not only effectively absorb and filter the extremely high frequency destructive impact force in the seismic wave as a primary buffer barrier, preventing the subsequent precision gear mechanism from rigidly colliding and breaking, but also provides a precise and controllable positive restoring force (i.e. optimal positive stiffness) for the entire vibration absorption system through elastic element 33. This enables the system to maintain excellent following and reset capabilities when the main structure oscillates back and forth, thus laying a stable and continuous dynamic input foundation for the efficient displacement amplification of the subsequent gear mechanism.

[0021] Furthermore, as a preferred embodiment of this solution and not a limitation, it also includes a pad 8 disposed on the base plate 1, and a plurality of first rollers 311 are arranged on the left and right sides of the lower end of the sliding plate 31, and the sliding plate 31 slides on the pad 8 via the first rollers 311.

[0022] In this embodiment, to ensure that the initial horizontal displacement transmitted from the external main structure can be accurately input into the vibration absorption system with extremely low mechanical loss, a pad plate 8 with high flatness and high hardness is specially laid on the upper surface of the base plate 1 as a dedicated running guide surface. At the same time, multiple first rollers 311 are symmetrically embedded on the left and right sides of the lower end of the sliding plate 31. When the external excitation force drives the sliding plate 31 to move, the sliding plate 31 no longer has a large area of ​​direct dry friction contact with the base. Instead, it relies on the high-precision first rollers 311 at the bottom to perform smooth and fluid rolling displacement on the pad plate 8. The original sliding dry friction between the sliding plate and the base is transformed into rolling friction with an extremely low coefficient of friction. From the perspective of dynamic energy transfer, the frictional energy dissipation at the system input end is eliminated to the maximum extent. This fundamentally improves the response accuracy and vibration reduction energy utilization efficiency of the entire dynamic vibration absorption system to small displacement vibrations. At the same time, the independently detachable pad plate 8 also effectively avoids long-term reciprocating wear of the core load-bearing base plate 1, and greatly extends the maintenance-free cycle and service life of the vibration absorber.

[0023] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, the gear amplification mechanism 4 includes a small transmission gear 41 meshing with the gear transmission member 32 and a large transmission gear 42 meshing with the second rack 23. When the small transmission gear 41 rotates under the drive of the gear transmission member 32, it drives the large transmission gear 42 to rotate synchronously, thereby amplifying the input displacement and transmitting it to the core transmission member 2.

[0024] In this embodiment, when the external main structure generates a small displacement and drives the gear transmission component 32 in the elastic mechanism to move linearly, the transmission pinion 41 that meshes with it will be forced to rotate. Since the transmission large gear 42 and the transmission pinion 41 are designed as gear set components with rigid coaxial connection, the linear velocity of the edge of the large gear will be proportionally greater than the linear velocity of the pinion. As a result, the transmission large gear 42 will drive the second rack 23 that meshes with it to generate a significantly amplified linear displacement. Under the optimal dynamic parameter setting conditions, for example, when the gear amplification ratio is set to L=2, it is only necessary to strictly set the tooth ratio or pitch circle radius ratio of the transmission large gear 42 and the transmission pinion 41 to 2:1 during manufacturing. This will amplify the input displacement of the gear transmission component 32 by a full 2 ​​times without any delay at the purely mechanical level, and then accurately transmit it to the core transmission component 2. Compared with existing direct-drive shock absorbers that do not have displacement amplification, this design changes the sensitivity threshold of the dynamic vibration absorber to external excitation input. This allows the weak energy that would otherwise be unable to activate the subsequent damping and inertial capacitance components to be amplified into a large-stroke motion of the core transmission component 2 under conditions of minimal displacement load, such as the initial stage of an earthquake or light wind vibration. This highly efficient triggers the release of the negative stiffness preload spring with a pre-compression amount of 0.06m, and causes the eddy current damping element to generate a higher relative cutting speed per unit time, thus multiplying the damping energy dissipation efficiency. Ultimately, this achieves strong suppression of large displacement of the base isolation layer under strong earthquakes with extremely small physical dimensions.

[0025] Furthermore, as a preferred embodiment of this solution and not a limitation, the lower part of the gear amplification mechanism 4 is provided with a rotating bearing 43, and the base plate 1 is provided with a positioning column 11 for mounting and positioning the rotating bearing 43.

[0026] In this embodiment, during the high-speed and frequent forward and reverse rotation of the gear amplification mechanism, the positioning column 11 rigidly fixed on the base plate 1 establishes an absolutely stationary and anti-lateral displacement rotation center for the entire integrated large and small gear assembly. At the same time, a rotating bearing 43 is precisely fitted between the lower part of the gear assembly and the positioning column 11, so that the high-resistance sliding dry friction between the bottom end face of the large gear and the base plate is completely transformed into extremely low-damping rolling friction. From a physical structure perspective, this eliminates the lateral or radial runout that may be caused by the intense reciprocating meshing transmission between the transmission pinion and the gear transmission component, and between the transmission large gear and the second rack. This ensures that the gear pair is always at the optimal theoretical meshing pitch line, thereby realizing the optimal amplification efficiency of the system's set amplification ratio L=2 with extremely high precision and low energy loss.

[0027] Furthermore, as a preferred embodiment of this solution and not a limitation, the negative stiffness device 5 includes two symmetrically arranged negative stiffness mechanisms 51. Each negative stiffness mechanism 51 includes an annular cylinder 511 connected to the side of the pad 8 via a sliding bearing. A pre-compression spring 512 is provided inside the annular cylinder 511. A roller 513 is mounted on the head of the annular cylinder 511 facing the core transmission member 2. Under the action of the pre-compression spring 512, the roller 513 presses against the annular portion 21 of the core transmission member 2. When the core transmission member 2 moves, the horizontal spring compression force is converted into a vertical component force to assist the movement of the core transmission member 2.

[0028] In this embodiment, when the core transmission component 2 undergoes linear reciprocating motion under the combined drive of external excitation and gear amplification mechanism, the circular cam profile (i.e., the annular portion 21) with a maximum displacement (i.e., maximum diameter) of 0.12m, which is centrally located, will move up and down accordingly. At this time, the negative stiffness mechanisms 51 symmetrically arranged on both sides begin to work seamlessly together. The horizontal spring compression thrust is continuously and tightly pressed against the cam profile of the annular portion 21 by the roller 513 installed at the head of the annular cylinder 511, and the force is cleverly decomposed orthogonally at the physical contact point. Since the horizontal force of the symmetrical rollers on both sides acting on the cam is always completely canceled out, while the vertical direction will generate a vertical component force that is consistent with the current direction of motion of the core transmission component 2, the original horizontal potential energy of the spring is instantly converted into a unidirectional force that assists and promotes the continued movement of the main structure. Finally, at the macroscopic level of the vibration absorber system, the optimal negative stiffness total effect of up to -46.27N / m is precisely generated. The annular cylinder 511 is connected to the external guide structure by a high-precision sliding bearing placed inside, ensuring smooth sliding of the annular cylinder with extremely low frictional resistance. This minimizes the adverse effects of dry friction on the device's function under minor vibrations. It can spontaneously provide a force to amplify the displacement of the main structure when the towering main structure is in an extremely low frequency range or only undergoes minimal displacement vibration. At the dynamic level, it directly offsets part of the system's large positive stiffness (such as the positive stiffness compression spring with a stiffness coefficient as high as 1779.44 N / m directly used in the front-stage vibration absorption). This significantly reduces the natural frequency of the entire coupling structure, making it easier to match the dominant low-frequency band of destructive seismic waves to strongly suppress the resonance peak of the structure. This greatly broadens the effective vibration reduction and energy dissipation working frequency band of the dynamic vibration absorber and also provides a longer working stroke and a higher relative tangential velocity for the subsequent damping elements.

[0029] Furthermore, as a preferred embodiment of this solution and not a limitation, the pad 8 is provided with a buckle 81 that passes through the side of the annular cylinder 511 and slides with the inner wall of the annular cylinder 511. The pre-compression spring 512 is provided between the buckle 81 and the negative stiffness mechanism 51 to ensure the compression state of the spring. The negative stiffness mechanism 51 is provided with second rollers 514 on both sides to reduce friction with the base plate 1.

[0030] In this embodiment, during the assembly and operation of the negative stiffness mechanism 51, the buckle 81 fixed inside the pad 8 penetrates and extends into the annular cylinder 511. It serves not only as a precision guide and limiting component for the reciprocating linear sliding of the annular cylinder 511, but also as a core force-reaction base, firmly restricting the pre-compression spring 512 between the buckle 81 and the working surface at the front end of the mechanism. This ensures, in terms of physical structure, that the spring is always in the initial pre-compression state required by the design. Before the circular cam profile with a maximum displacement diameter of 0.12m in the middle of the core transmission component reciprocates and compresses... When the end roller is in operation, the annular cylinder 511 slides relative to the pad 8, and the pre-compression spring 512 is further compressed or released under the support of the fixed buckle 81, thereby accurately outputting the set stiffness value to the core transmission component (such as using a pre-compression spring with a stiffness of 23.135 N / m to achieve the optimal auxiliary thrust on one side of the system, and finally synthesizing the total negative stiffness of -46.27 N / m required by the system); at the same time, with the reciprocating high-frequency extension and retraction of the negative stiffness mechanism 51, the second rollers 514 arranged on both sides of its main body make smooth rolling displacement on the bearing surface of the base plate 1. The built-in buckle 81 not only greatly reduces the overall axial length of the mechanism to adapt to the cramped space of the isolation layer, but also fundamentally eliminates the radial instability bending (i.e. buckling phenomenon) and pre-pressure attenuation that may occur in the pre-compression spring 512 under long-term high-frequency oscillation or strong shock, ensuring long-term accurate output throughout the life cycle of the negative stiffness effect; while the introduction of the second roller 514 completely eliminates the large-area sliding dry friction between the annular cylinder and the base, so that the extremely small driving force induced by small seismic waves, buffered by the positive stiffness spring (stiffness 1779.44N / m) and amplified by the amplification ratio L=2 can also trigger the negative stiffness mechanism without frictional resistance, improving the system's sensitivity to suppressing low-frequency resonance of small displacement of the main structure.

[0031] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, the inertial capacity device 6 includes a driven pinion 61 rotatably connected to the base plate 1 and meshing with the first rack 22, a driven gear 62 coaxially connected to the driven pinion 61, a flywheel 63 rotatably connected to the base plate 1, and a flywheel disk 64 coaxially connected to the flywheel 63 and meshing with the driven gear 62. The first rack 22 drives the driven gear 62 to rotate, thereby driving the flywheel 63 to rotate at high speed to generate an equivalent mass.

[0032] In this embodiment, when the core transmission component is driven by a linear displacement amplified by a gear mechanism with a set amplification ratio of L=2, the first rack 22 above it will synchronously translate, thereby causing the driven pinion 61, which is tightly meshed with it, to rotate rapidly. Since the driven pinion 61 and the driven gear 62 are rigidly coaxially connected, the synchronous rotation speed and the increased radius bring about a significant increase in linear velocity. Subsequently, the high-speed rotating driven gear 62 drives the flywheel 64 that meshes with it again, ultimately causing the coaxial flywheel 63 to rotate at an extremely high angular velocity. A frustum can be set on the base plate, and the driven gear 62, the driven pinion 61, and the flywheel 63 are connected by a high-precision sliding bearing, ensuring smooth rotation with extremely low frictional resistance and minimizing the adverse effects of dry friction on the device's function under slight vibrations. Based on the derivation of the system's kinetic energy equivalence principle, under the condition of a set inertia-to-capacity ratio of 0.1 and a main structure mass of 23.8 kg, the target equivalent mass needs to reach 2.38 kg. This invention, through the aforementioned multi-stage speed-increasing gear set (for example, the gear ratio of both the large and small gears is set to 25:17 and the radius of the small gear is set to 0.01 m), only needs to use a flywheel with a radius of 0.03 m and an extremely small physical mass (the calculated total flywheel mass is only 0.245 kg, and the mass of a single symmetrically arranged disk is even lower than 0.1225 kg). In the event of a strong earthquake, it can instantly generate a huge equivalent inertial force of nearly 10 times its actual physical mass. This not only perfectly avoids the fatal defect of traditional tuned mass dampers (TMDs) that add extra dead load to the building foundation due to their large physical counterweight, but also achieves efficient low-frequency vibration control with an extremely lightweight and compact physical volume.

[0033] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, the eddy current damping device 7 includes an annular copper sheet 71 disposed on the flywheel 63, and a magnet assembly 72 located on the upper and lower sides of the annular copper sheet 71; the annular copper sheet 71 follows the rotation of the flywheel 63 and moves within the magnetic field arranged by the magnet assembly 72 to cut magnetic field lines, thereby generating eddy current damping.

[0034] In this embodiment, when the system is in anti-vibration and vibration reduction mode, the flywheel 63, driven by the pre-gear amplification mechanism, rotates at high speed, which synchronously drives the annular copper plate 71, which is tightly fixed on its end face, to rotate at high speed. At this time, the magnet assembly 72, which is fixed on the relevant stationary frame and precisely suspended on the upper and lower sides of the annular copper plate 71, for example, uses a high-performance neodymium iron boron square permanent magnet to construct a high-intensity constant magnetic field in the air gap. As the annular copper plate 71 rotates at high speed, the free electrons inside it continuously cut the constant magnetic field lines, based on electromagnetic induction. The law induces a closed-loop current within the copper plate. This eddy current then generates a Lorentz force that interacts with the main magnetic field, forming a non-contact electromagnetic damping torque that constantly opposes the rotation of the flywheel. With the extremely high rotational linear velocity provided by the gear set, this highly efficient method converts the destructive seismic energy transmitted from the foundation isolation layer into heat energy for dissipation. This purely physical electromagnetic coupling damping generation mechanism brings significant benefits: according to the dynamic optimization design theory formula, under the condition that the optimal damping requirement of this system is strictly set at 30.72 N·s / m, due to the use of a highly symmetrical double flywheel with magnets arranged on both the upper and lower surfaces of each flywheel, the system only needs to finely distribute the damping coefficient of each side within a very small physical scale to achieve 7.68. N·s / m is sufficient. For example, the width a=0.01m and length b=0.0083m of a single square permanent magnet can be precisely set through theoretical calculations, and the air gap can be adjusted to make the magnetic induction intensity B=1.2T, and it is paired with a high-quality low resistivity conductive copper plate with a thickness t=0.002m. This not only realizes the theoretical optimal energy consumption parameters of the system with extremely high precision, but also eliminates the fatal engineering hidden dangers of fluid leakage, aging failure of seals and serious decline of damping force due to long-term high-frequency wear of friction dampers, which are very easy to occur in traditional viscous fluid dampers. This endows the building foundation shock absorber with extremely high maintenance-free characteristics for decades or even the same lifespan as the building and absolute stability of performance in extreme environments. The annular copper sheet can be arranged symmetrically on the top and bottom or fixed to the flywheel 63 on either the top or bottom. This scheme prefers the symmetrical arrangement.

[0035] Furthermore, as a preferred embodiment of this solution and not a limitation, it includes two symmetrically arranged pads 8, with a sliding groove 82 formed between the two pads 8, and a third roller 24 provided at both ends of the core transmission component 2, with the second rack 23 located within the sliding groove 82.

[0036] In this embodiment, by symmetrically setting two pads 8 with high flatness and high strength at the bottom of the system, not only are support bases provided for both ends of the core transmission component 2, but a sliding groove 82 is also reserved between the two pads. When the core transmission component 2 is powerfully driven by the gear mechanism with a set amplification ratio of L=2 and performs a reciprocating large stroke linear motion with a maximum displacement of 0.12m, the third rollers 24 precisely installed at both ends will roll smoothly with extremely low frictional resistance against the bearing surface of the pad 8. At the same time, the second rack 23, which is used to receive the power input from the bottom layer, is located inside the sliding groove 82 and performs safe, precise meshing transmission with the large transmission gear below without any spatial interference with other upper-level mechanisms. Compared with the existing technology that uses a single-rail guide or a coarse-type shock absorber transmission base without lateral constraints, this design ensures that the transmission shaft is always on the absolute theoretical center line. This allows the excitation energy input from the outside and buffered by a positive stiffness spring with a stiffness set at 1779.44 N / m to reach the inertial capacitance and damping core components of the subsequent stage with high mechanical transmission efficiency. At the same time, the design of sinking and hiding the second rack 23 in the sliding groove 82 between the two pads 8 effectively compresses the overall Z-axis structural thickness of the shock absorber, greatly improving the high-density integration of the system to perfectly adapt to the limited installation space of the seismic isolation layer at the bottom of the building.

[0037] To visually demonstrate the vibration reduction performance of this application in a multi-degree-of-freedom structure, a five-story frame structure was selected. Since the first-order modal vector (i.e., the first mode shape) reveals the most likely and primary deformation form of the structure under seismic dynamic loads, the first-order modal vector was calculated based on modal analysis theory under the Rayleigh damping assumption, combined with the stiffness and mass matrices of the constructed system, to assess the structural dynamic response, conduct seismic design, health monitoring, and vibration control. The equivalent mass and damping value of the first-order mode were then obtained. The main structure mass was taken as 23.8 kg, the spring stiffness as 2200 kN / m, and the inherent damping of the structure was taken as... This operation is to simplify a multi-degree-of-freedom structure into a single-degree-of-freedom structure, making it easier to calculate the optimal parameters. Figure 12 This is the structural dynamics analysis model of the device placed on a single-degree-of-freedom theoretical model framework. The following equation is the structural dynamics equation of the single-degree-of-freedom structural model: , where L = r2 / r1.

[0038] Furthermore, based on the analytical solution of the equation, using fixed-point theory and H∞ control, with the minimization of the main structure's displacement response as the optimization objective, analytical expressions for the optimal tuning ratio, optimal damping ratio, and optimal negative stiffness coefficient of the system are derived. Specific parameters when the inertia-to-capacity ratio is 0.1 are shown in the table below. (Inertia-to-capacity ratio is 0.1, amplification ratio...) =r2 / r1, and the specific structural parameters of the vibration absorber are shown in the table below. The specific calculation uses the working condition with an amplification ratio of L=2. To achieve L=2, it is only necessary to set the tooth ratio of the large and small gears of gear 23 to 2:1.

[0039] Table 1 Optimal parameters of the vibration absorber

[0040] Table 2 Vibration Absorber Design Parameters

[0041] The elastic element 33 uses a spring with a spring stiffness coefficient of 1779.44 N / m; The amplification ratio of the gear amplification mechanism is set to L=2, that is, the ratio of the number of teeth of the large and small gears is set to 28:14, and the amplification ratio L can be flexibly adjusted according to the ratio of the number of teeth of the large and small gears. Calculation of the inertial model: The gear ratio of both the large and small gears is 25:17; Small gear radius rack speed Gear angular velocity:

[0042] The moment of inertia of a flywheel:

[0043] in For the mass of the disk, The radius is the flywheel radius.

[0044] Rotational kinetic energy: ,in This is the gear transmission ratio.

[0045] Let the relative velocity between the two ends of the inertial container be... Inertial mass is The equivalent translational kinetic energy is:

[0046] Equivalent to the rotational kinetic energy above, simplified as follows:

[0047] Next, we calculate the required mass of the flywheel, taking the flywheel radius. =0.03m:

[0048] In the formula Since the inertia-to-mass ratio is taken as 0.1, the radius of the pinion is... =0.01m, the main structure mass is 23.8kg, then =2.38kg, calculated as follows =0.245kg, its mass magnification reaches 10 times. Since the device has two flywheels arranged symmetrically, it is only necessary to place a 0.1225kg disc mass block with the same radius as the flywheel on the two flywheels to achieve an equivalent mass of 2.38kg.

[0049] Calculation of the damping model: The theoretical value of the eddy current damping coefficient generated by a single magnet can be expressed as:

[0050] In the formula: The damping force generated by the eddy current effect in the eddy current damper. The horizontal velocity of the conductor plate. The width of the permanent magnet. The length of the permanent magnet; It represents the magnetic flux density; The thickness of the conductor plate; Let be the resistivity of the conductor plate.

[0051] Using a copper plate as the conductor, the resistivity of copper is... We can obtain:

[0052] The optimal damping coefficient for this operating condition is 30.72 N·s / m. The eddy current damping of this device is arranged symmetrically on the left and right sides, and symmetrically on the top and bottom sides of one side of the flywheel. Therefore, the damping coefficient of only one side is 30.72 / 4=7.68 N·s / m. For example: a=0.01m, b=0.0083m, t=0.002m, B=1.2T.

[0053] Calculation of negative stiffness model: The stiffness of the negative stiffness spring is -46.27 N / m. Due to the symmetrical arrangement, only one side of the device needs to generate a stiffness of -23.135 N / m.

[0054] Figure 8 This is a force analysis diagram of the push rod and the moving cam mechanism. Figure 9 A simplified model diagram of the cam force is provided. In the dynamic analysis of the above cam mechanism, the inertial force of the rollers is ignored. The pressure of the pre-compressed spring, , The constraint reaction force of the push rod support, The force exerted by the cam on the push rod, The force exerted by the pushrod on the cam. , Action and reaction forces The angle between the outer normal of the moving cam and the y-axis. The distance between the two supports. This is the distance from the contact point of the pushrod cam to the right end support.

[0055] Neglecting the inertial force of the push rod and the frictional force at the support, the theoretical profile of the cam in the negative stiffness device is obtained:

[0056] In the formula: This is the spring pre-compression amount. denoted as the spring stiffness ratio, and n represents the number of symmetrically arranged pre-compression devices.

[0057] By transforming the equation of the ellipse and taking the implicit derivative of the theoretical contour line, the actual machining contour line of the ellipse can be obtained:

[0058] Based on the derivation of the theoretical and actual contour lines of the cam roller mechanism, let... The spring stiffness ratio is used to select different spring stiffness ratios. Or set different spring precompression amounts It will have a significant impact on the actual contour lines processed by the equipment, such as Figure 10 and Figure 11 As shown.

[0059] The experimental setup uses n=2, meaning the negative stiffness elements are symmetrically arranged on both sides. Only one side needs to generate a stiffness of -23.135 N / m. The spring stiffness ratio is set to k=1, meaning the actual spring stiffness is the same as the theoretical spring stiffness, a pre-compression spring of 23.135 N / m. Figure 10 It can be seen that the contour is circular, and the maximum displacement, i.e., the maximum diameter, is taken as 0.12m. Figure 11 It can be seen that when the maximum displacement is 0.12m, the spring pre-compression is 0.06m.

[0060] In summary, the cam profile is circular with a diameter of 0.12m, the spring stiffness is selected as 23.135 N / m, and the spring pre-compression is 0.06m. Under the condition of satisfying the above conditions, with the connection of the annular cylinder, the distance between the L-shaped plate and the cam is reasonably set to determine the radius of the roller.

[0061] The working principle of this embodiment is as follows: When an earthquake causes a small horizontal displacement in the base isolation layer, this displacement is first buffered by a positive stiffness spring, and then amplified by a gear amplification mechanism, powerfully driving the core transmission component to perform a large-stroke linear translation. During the translation process, the system simultaneously triggers a three-effect synergistic damping: First, the cam in the middle of the core transmission component deviates from its initial center point, allowing the pre-compressed springs on both sides to release space, instantly converting the spring potential energy into a forward thrust in the same direction as the motion, thereby precisely outputting a negative stiffness effect to reduce the system's natural frequency and broaden the damping frequency band; second, the rack at the end of the core transmission component drives the flywheel of the inertial capacitance device to rotate at high speed, instantly generating a huge equivalent tuned mass based on the kinetic energy equivalence principle to suppress structural sway; finally, the high-speed rotating flywheel drives the copper sheet to cut magnetic field lines in a constant magnetic field, generating highly efficient non-contact eddy current damping. Ultimately, this system, through a pure physical coupling mechanism of "displacement amplification - potential energy release forward thrust - high-frequency tuning energy dissipation," achieves extremely sensitive and efficient safe control of large displacements in the base isolation layer during strong earthquakes.

[0062] The above are implementation methods provided in conjunction with specific content, and it is not intended that the specific implementation of this application is limited to these descriptions. Any methods or structures that are similar to those of this application, or any technical deductions or substitutions made based on the concept of this application, should be considered within the scope of protection of this application.

Claims

1. A tuned negative stiffness inertial capacitance dynamic vibration absorption system with main structure displacement amplification, characterized in that, The system includes a base plate (1), a core transmission component (2) slidably mounted on the base plate (1), an elastic mechanism (3) for connecting to the external main structure and receiving the displacement of the external main structure, a gear amplification mechanism (4) connected between the elastic mechanism (3) and the core transmission component (2) and used to amplify the received displacement and transmit it to the core transmission component (2), a negative stiffness device (5) symmetrically arranged on both sides of the core transmission component (2) and cooperating with the core transmission component (2) to generate a negative stiffness effect, an inertial capacitance device (6) driven by the movement of the core transmission component (2) to generate an equivalent tuned mass, and an eddy current damping device (7) integrated with the inertial capacitance device (6) and used to generate eddy current damping when the inertial capacitance device (6) is in operation.

2. The tuned negative stiffness inertial capacitance dynamic vibration absorption system for main structure displacement amplification as described in claim 1, characterized in that, The core transmission component (2) includes an annular portion (21) located in the middle and used to cooperate with the negative stiffness device (5), and a first rack (22) and a second rack (23) located on the upper and lower sides of the annular portion (21), respectively. The first rack (22) is used to cooperate with the inertial capacity device (6), and the second rack (23) is used to cooperate with the gear amplification mechanism (4).

3. A tuned negative stiffness inertial capacitance dynamic vibration absorption system for main structure displacement amplification as described in claim 2, characterized in that, The elastic mechanism (3) includes a sliding plate (31), a gear transmission component (32), and an elastic component (33) disposed between the sliding plate (31) and the gear transmission component (32). An external displacement force can drive the sliding plate (31), thereby compressing the elastic component (33) and causing the gear transmission component (32) to move.

4. A tuned negative stiffness inertial capacitance dynamic vibration absorption system for main structure displacement amplification as described in claim 3, characterized in that, It also includes a pad (8) disposed on the base plate (1), and a plurality of first rollers (311) are arranged on the left and right sides of the lower end of the sliding plate (31). The sliding plate (31) slides on the pad (8) through the first rollers (311).

5. A tuned negative stiffness inertial capacitance dynamic vibration absorption system for main structure displacement amplification as described in claim 3, characterized in that, The gear amplification mechanism (4) includes a small transmission gear (41) meshing with the gear transmission component (32) and a large transmission gear (42) meshing with the second rack (23). When the small transmission gear (41) rotates under the drive of the gear transmission component (32), it drives the large transmission gear (42) to rotate synchronously, thereby amplifying the input displacement and transmitting it to the core transmission component (2).

6. A tuned negative stiffness inertial capacitance dynamic vibration absorption system for main structure displacement amplification as described in claim 5, characterized in that, The lower part of the gear amplification mechanism (4) is provided with a rotating bearing (43), and the base plate (1) is provided with a positioning column (11) for the rotating bearing (43) to be installed and positioned.

7. A tuned negative stiffness inertial capacitance dynamic vibration absorption system for main structure displacement amplification as described in claim 4, characterized in that, The negative stiffness device (5) includes two symmetrically arranged negative stiffness mechanisms (51). The negative stiffness mechanism (51) includes an annular cylinder (511) connected to the side of the pad (8) by a sliding bearing. The annular cylinder (511) is provided with a pre-compression spring (512). A roller (513) is installed on the head of the annular cylinder (511) facing the core transmission member (2). The roller (513) presses against the annular part (21) of the core transmission member (2) under the action of the pre-compression spring (512). When the core transmission member (2) moves, the horizontal spring compression force is converted into a vertical component force to assist the movement of the core transmission member (2).

8. A tuned negative stiffness inertial capacitance dynamic vibration absorption system for main structure displacement amplification as described in claim 7, characterized in that, The pad (8) is provided with a buckle (81) that passes through the side of the annular cylinder (511) and slides with the inner wall of the annular cylinder (511). The pre-compression spring (512) is provided between the buckle (81) and the negative stiffness mechanism (51) to ensure the compression state of the spring. The negative stiffness mechanism (51) is provided with second rollers (514) on both sides to reduce friction with the base plate (1).

9. A tuned negative stiffness inertial capacitance dynamic vibration absorption system for main structure displacement amplification as described in claim 2, characterized in that, The inertial capacity device (6) includes a driven pinion (61) rotatably connected to the base plate (1) and meshing with the first rack (22), a driven gear (62) coaxially connected to the driven pinion (61), a flywheel (63) rotatably connected to the base plate (1), and a flywheel disk (64) coaxially connected to the flywheel (63) and meshing with the driven gear (62). The first rack (22) drives the driven gear (62) to rotate, thereby driving the flywheel (63) to rotate at high speed to generate equivalent mass.

10. A tuned negative stiffness inertial capacitance dynamic vibration absorption system for main structure displacement amplification as described in claim 9, characterized in that, The eddy current damping device (7) includes an annular copper sheet (71) disposed on the flywheel (63) and a magnet assembly (72) located on the upper and lower sides of the annular copper sheet (71); the annular copper sheet (71) follows the rotation of the flywheel (63) and moves to cut magnetic field lines within the magnetic field arranged by the magnet assembly (72), thereby generating eddy current damping.

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