Self-adaptive anti-lifting device and method based on negative stiffness compensation

Abstract

The self-adaptive anti-lifting device based on negative stiffness compensation comprises a friction pendulum shock insulation support and a negative stiffness compensation assembly, the friction pendulum shock insulation support comprises a first seat plate, a spherical crown body and a second seat plate, and the negative stiffness compensation assembly comprises an upper structure connecting plate, a rigid-flexible assembly, a negative stiffness compression spring, a spherical hinge and an inhaul cable. The rigid-flexible assembly comprises a plurality of elastic plates and a plurality of rigid plates, a first groove is formed in the bottom of the rigid-flexible assembly, a spherical hinge and a plurality of negative-stiffness compression springs are arranged in the first groove, the upper end of the spherical hinge is fixedly connected with the groove bottom wall of the first groove, and the lower end of the spherical hinge extends into a second groove in the top of the first seat plate; the lower end of the spherical hinge is rotationally connected with the first base plate, and the multiple inhaul cables surround the rigid-flexible assembly. Dynamic and self-adaptive adjustment of lifting can be achieved, the normal shock insulation function of the structure is not affected while the whole structure is effectively prevented from being lifted, and the safety and stability of the structure under the action of extreme loads are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge seismic isolation, and more specifically, relates to an adaptive anti-lifting device and method based on negative stiffness compensation. Background Art

[0002] The safety and stability of large structures such as bridges and high-rise buildings face severe tests when encountering extreme loads such as earthquakes and strong winds.

[0003] Friction Pendulum System (FPS) is an isolation device widely used in structures such as bridges and high-rise buildings, and plays an important role. The structure of a conventional friction pendulum isolation bearing includes an upper base plate, a spherical crown and a second base plate. Its main working principle is to achieve the isolation effect through the sliding friction and swinging principle of the spherical crown. Specifically, when horizontal loads such as earthquakes act on the structure, the spherical crown in the friction pendulum isolation bearing will slide on the concave spherical surface of the lower base plate, and at the same time use the gravity of the upper structure as a restoring force to enable the structure to automatically reset after the earthquake. This method can effectively extend the natural vibration period of the structure, reduce the transmission of seismic force to the structure, and thus reduce the response of the structure in earthquakes, greatly improving the safety of the structure under earthquakes. This is also the key to its widespread application in many large bridges and other projects.

[0004] However, friction pendulum isolation bearings also present challenges in actual engineering applications. One prominent issue is that under extreme loads such as strong earthquakes and strong winds, the spherical crown can slide. Because the spherical crown contacts the curved surfaces of both the upper and lower base plates, this sliding can cause the upper base plate and the building's superstructure, which it supports, to tilt and lift, leading to sway, instability, and uneven loads on the building's superstructure.

[0005] At present, the industry has taken some measures to address the problem of friction pendulum isolation bearing lifting. Traditional passive anti-lifting devices are a relatively common solution, such as limit rods, fixed connectors, etc. The structural form of these devices is relatively fixed, and they limit the lifting of the bearings through mechanical connections. However, this type of device has obvious limitations. Because under different earthquake or wind load intensities, the load conditions are constantly changing, and the passive anti-lifting device cannot dynamically adjust its own constraint stiffness according to these changes. This leads to a problem. In some cases, the constraint may be too strong, which will affect the normal isolation function of the friction pendulum isolation bearing and prevent it from exerting its due isolation effect; in other cases, the constraint may be insufficient and cannot effectively prevent the lifting of the bearing, and cannot meet the needs of actual engineering.

[0006] In addition to the limitations mentioned above, most existing anti-lift technologies lack adaptive adjustment capabilities. In other words, they cannot make real-time adjustments based on the actual load-bearing conditions and displacement states of the supports to adapt to complex and changing load environments. In actual engineering scenarios, the magnitude and direction of the load may change at any time, which requires anti-lift measures to be able to make corresponding adjustments in a timely manner to achieve efficient and accurate anti-lift control. However, most current technologies cannot meet this requirement, which also limits their application effect and scope to a certain extent.

[0007] In addition, most of the existing anti-lifting devices have a single function. They only focus on how to limit the lifting of the bearings, without fully considering how to organically combine them with the seismic isolation function of the friction pendulum isolation bearings. As a result, under different working conditions, it is difficult for the structure to meet multiple complex requirements such as earthquake resistance and reset at the same time. For example, in some cases, in addition to preventing the lifting of the bearings, it is also necessary to ensure that the structure can be reset in time after the earthquake to restore its normal use function. However, the existing anti-lifting devices are often unable to take into account these multiple needs. This means that in actual applications, it may be necessary to add other devices or take other measures to make up for this shortcoming, thereby increasing the complexity and cost of the project.

[0008] In order to solve the problem of anti-uplift of friction pendulum isolation bearings, some studies have attempted to solve the uplift problem by improving the structural design of the friction pendulum isolation bearings themselves. For example, adding auxiliary sliders, optimizing the curved surface shape, etc., these methods aim to improve the vertical bearing capacity of the bearing to better resist the uplift tendency under extreme loads. Some other studies have adopted the solution of additional damping devices to suppress the uplift of the bearing by consuming energy. However, these methods have also exposed many problems in practical applications. For example, the structure becomes more complicated, which undoubtedly increases the manufacturing and installation costs. At the same time, it may also have a greater impact on the original isolation performance of the bearing, and in some cases it may even be counterproductive and fail to achieve the expected effect. Summary of the Invention

[0009] In response to the above-mentioned defects or improvement needs of the prior art, the present invention provides an adaptive anti-lifting device and method based on negative stiffness compensation. By introducing a negative stiffness compensation component to perform negative stiffness compensation, dynamic and adaptive adjustment of the lifting of the friction pendulum isolation support is achieved, effectively preventing the overall lifting of the adaptive anti-lifting device without affecting its normal isolation function, thereby improving the safety and stability of the structure under extreme loads.

[0010] To achieve the above objectives, according to one aspect of the present invention, an adaptive anti-lift device based on negative stiffness compensation is provided, characterized in that it includes a friction pendulum seismic isolation support and a negative stiffness compensation assembly, the friction pendulum seismic isolation support includes a first seat plate, a spherical crown, and a second seat plate arranged in sequence from top to bottom, the bottom of the first seat plate is provided with a first concave spherical surface, the top of the spherical crown is provided with a first convex spherical surface in contact with the first concave spherical surface, the top of the second seat plate is provided with a second concave spherical surface, and the bottom of the spherical crown is provided with a second convex spherical surface in contact with the second concave spherical surface, wherein:

[0011] The negative stiffness compensation component includes an upper structure connecting plate, a rigid-flexible assembly, a negative stiffness compression spring, a ball joint and a cable. The rigid-flexible assembly is located between the upper structure connecting plate and the first seat plate and is fixedly connected to the upper structure connecting plate and the first seat plate respectively. The rigid-flexible assembly includes a plurality of plates stacked and fixedly connected together. These plates include a plurality of elastic plates and a plurality of rigid plates, and the elastic plates and the rigid plates are arranged alternately. A first groove is provided at the bottom of the rigid-flexible assembly, and the bottom wall of the first groove is a part of the bottom surface of one of the rigid plates. The ball joint and There are multiple negative stiffness compression springs, the upper end of each negative stiffness compression spring is fixedly connected to the bottom wall of the first groove and the lower end is connected to the first seat plate, each negative stiffness compression spring is in a compressed state, the upper end of the ball joint is fixedly connected to the bottom wall of the first groove, the lower end of the ball joint extends into the second groove at the top of the first seat plate, and the lower end of the ball joint is rotatably connected to the first seat plate. There are multiple cables and these cables surround the rigid-flexible assembly, each cable is in a pre-tensioned state, and the upper and lower ends of each cable are respectively connected to the upper structure connecting plate and the first seat plate.

[0012] Preferably, the first seat plate includes an adaptive swing block, a middle connecting plate, an upper curved sliding connecting plate and an upper curved sliding layer, which are arranged in sequence from top to bottom and fixedly connected together, the edges of the middle connecting plate respectively extend beyond the edges of the adaptive swing block and the edges of the upper curved sliding connecting plate, the lower ends of each of the cables are respectively fixedly connected to the middle connecting plate, and the first concave spherical surface is arranged at the bottom of the upper curved sliding layer.

[0013] Preferably, the adaptive swing block includes a polytetrafluoroethylene block and a stainless steel block arranged from top to bottom and fixedly connected together, and the second groove is provided on the polytetrafluoroethylene block.

[0014] Preferably, the second seat plate includes a lower curved sliding layer, a lower curved sliding connecting plate and a lower curved sliding limit seat which are arranged in sequence from top to bottom and fixedly connected together, the second concave spherical surface is arranged on the top of the lower curved sliding layer, and the edge of the lower curved sliding limit seat is provided with an annular flange for limiting the sliding stroke of the spherical crown.

[0015] Preferably, the first groove is located in the middle of the rigid-flexible assembly, and the negative stiffness compression spring surrounds the ball joint.

[0016] Preferably, the lower end of the ball joint is rotationally connected to the first seat plate by contacting a spherical surface, an ellipsoidal surface or an 8-shaped curved surface.

[0017] Preferably, the first seat plate is provided with a plurality of first ear plates, and the second seat plate is provided with a second ear plate at a position corresponding to each of the first ear plates.

[0018] Preferably, the rigid plates are made of high-strength alloy steel, and the elastic plates are made of rubber. Any adjacent rigid plates and elastic plates are bonded with an adhesive and then fixed together by rivets.

[0019] Preferably, the top and bottom of the rigid-flexible assembly are both made of elastic plates.

[0020] According to another aspect of the present invention, there is also provided an anti-lifting method of an adaptive anti-lifting device based on negative stiffness compensation, characterized in that it comprises the following steps:

[0021] 1) The upper structure connecting plate is fixedly installed on the upper structure of a building, and the second seat plate is fixedly installed on the lower structure of the building, wherein the building is a highway bridge, a railway bridge or a high-rise building;

[0022] 2) When the lower structure of the building is impacted by a horizontal load, the second convex surface of the spherical crown slides on the second concave surface of the second seat plate, while the first seat plate rotates relative to the ball joint and one end of the first seat plate is lifted, causing the first seat plate to tilt. The tilted first seat plate squeezes the rigid-flexible assembly and the negative stiffness compression spring, thereby reducing the impact of the horizontal load on the upper structure connecting plate, thereby reducing the vibration and lifting of the upper structure connecting plate.

[0023] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0024] 1) The present invention is an adaptive anti-lifting device based on negative stiffness compensation, which introduces a negative stiffness compensation component. The rigid-flexible assembly of the negative stiffness compensation component is composed of multiple elastic plates and multiple rigid plates alternately stacked and fixedly connected. This alternating arrangement allows the rigid-flexible assembly to have a certain rigidity to bear and transmit force, and also has elastic properties that can deform to adapt to different stress conditions. The first groove is opened at the bottom of the rigid-flexible assembly, and a ball joint and multiple negative stiffness compression springs are arranged in the groove. When the negative stiffness compression spring is subjected to force, its stiffness becomes negative. This means that when an external force acts on the spring, the deformation of the spring will increase rather than decrease, thereby absorbing energy. This characteristic enables the negative stiffness spring to effectively reduce vibration and impact. The negative stiffness compression spring is combined with a conventional rigid-flexible assembly with positive stiffness to achieve adjustment and compensation of the overall stiffness. The negative stiffness compression spring and the rigid-flexible assembly can work together to reduce or eliminate the impact. When the lower foundation of the building is impacted, the impact passes through the second seat plate, The force transmitted to the upper structure connecting plate by the spherical crown and the first seat plate reduces the vibration and lifting of the upper structure connecting plate, so that the upper structure connecting plate is affected very little or basically unaffected, and the upper structure of the building supported by the upper structure connecting plate is also affected very little. The present invention uses the elastic force of the negative stiffness compression spring and the rigid-flexible assembly to balance the lifting force, which can avoid the problem caused by the upper structure of the building being lifted due to the overall lifting of the adaptive anti-lifting device, and significantly improves the safety of the structure under extreme loads. It is particularly suitable for occasions when loads such as earthquakes and strong winds act on the lower foundation of the building.

[0025] 2) Unlike traditional passive anti-lifting devices, the adaptive anti-lifting device based on negative stiffness compensation of the present invention, the rigid-flexible assembly and the negative stiffness compression spring of the negative stiffness compensation component can perform dynamic and adaptive elastic deformation (stiffness adjustment) according to the actual force and displacement state. Under different load conditions, such as earthquake waves or impact loads of different intensities, the force conditions of the various components of the adaptive anti-lifting device will change in real time. The elastic plate and the rigid plate in the rigid-flexible assembly will undergo corresponding deformation after being subjected to force, and this deformation will change the overall stiffness characteristics of the negative stiffness compensation component. At the same time, the rotating connection mode of the ball joint enables the first seat plate to rotate and displace within a smaller range, further promoting the automatic adjustment of the stiffness of the negative stiffness compensation component, realizing adaptive adjustment to different working conditions, and avoiding the problem of excessive or insufficient constraints that may occur in traditional fixed stiffness devices under different loads.

[0026] 3) The adaptive anti-lifting device based on negative stiffness compensation of the present invention combines the original isolation function of the friction pendulum isolation bearing and the isolation function of the negative stiffness compensation component. The friction pendulum isolation bearing mainly relies on the sliding friction of the spherical crown on the second seat plate and its own swinging principle to achieve isolation. The negative stiffness compensation component of the present invention is cleverly combined with the friction pendulum isolation bearing in design and layout, and its mechanical effects in the horizontal and vertical directions are coordinated with each other. Under the action of horizontal seismic force, the spherical crown can still slide freely on the second seat plate, consume seismic energy through sliding friction, and use the gravity of the upper structure to achieve automatic reset after the earthquake, extend the natural vibration period of the structure, and reduce the transmission of seismic force to the structure. The negative stiffness compensation component mainly works in a coordinated manner in the vertical and lateral directions to prevent lifting and assist in adjusting stiffness, and will not cause excessive interference to the horizontal sliding and swinging of the spherical crown, thereby ensuring that the isolation effect of the friction pendulum isolation bearing can be normally exerted during normal use, and realizing the effective unification of anti-lifting and seismic isolation functions.

[0027] 4) The adaptive anti-lifting device based on negative stiffness compensation of the present invention significantly improves the overall performance and reliability of the structure under extreme loads by preventing lifting, dynamically adjusting the stiffness of the negative stiffness compensation, and maintaining the seismic isolation function. For large structures such as bridges and high-rise buildings, this performance improvement means that the structure can better maintain stability in the face of earthquake disasters, reducing the risk of local or overall damage, and reducing maintenance costs and disaster losses. At the same time, reliable structural performance also helps to enhance the service life and safety of the building. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a three-dimensional schematic diagram of the present invention;

[0029] Figure 2 It is the front view of the present invention;

[0030] Figure 3 A schematic diagram of the present invention after a portion is cut away;

[0031] In all the drawings, the same reference numerals represent the same technical features, specifically:

[0032] 1. Upper structure connecting plate; 2. Friction pendulum isolation bearing; 3. Negative stiffness compensation component; 4. Spherical joint; 5. Cable; 6. Elastic plate; 7. Rigid plate; 8. Adaptive swing block; 9. Middle connecting plate; 10. First ear plate; 11. Upper curved sliding connecting plate; 12. Upper curved sliding layer; 13. Spherical crown; 14. Lower curved sliding layer; 15. Lower curved sliding connecting plate; 16. Lower curved sliding limit seat; 17. Negative stiffness compression spring; 18. Second ear plate; 19. Third ear plate; 20. Rigid-flexible assembly; 21. First seat plate; 22. Second seat plate. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0034] Reference Figures 1 to 3 An adaptive anti-lift device based on negative stiffness compensation includes a friction pendulum isolation bearing 2 and a negative stiffness compensation component 3. The friction pendulum isolation bearing 2 includes a first seat plate 21, a spherical crown 13, and a second seat plate 22 arranged in sequence from top to bottom. The bottom of the first seat plate 21 is provided with a first concave spherical surface, the top of the spherical crown 13 is provided with a first convex spherical surface in contact with the first concave spherical surface, the top of the second seat plate 22 is provided with a second concave spherical surface, and the bottom of the spherical crown 13 is provided with a second convex spherical surface in contact with the second concave spherical surface, wherein:

[0035] The negative stiffness compensation component 3 includes an upper structure connecting plate 1, a rigid-flexible assembly 20, a negative stiffness compression spring 17, a ball joint 4 and a cable. The rigid-flexible assembly 20 is located between the upper structure connecting plate 1 and the first seat plate 21 and is fixedly connected to the upper structure connecting plate 1 and the first seat plate 21 respectively. The rigid-flexible assembly 20 includes a plurality of plates stacked and fixedly connected together. These plates include a plurality of elastic plates 6 and a plurality of rigid plates 7, and the elastic plates 6 and the rigid plates 7 are arranged alternately. A first groove is provided at the bottom of the rigid-flexible assembly 20, and the bottom wall of the first groove is a part of the bottom surface of one of the rigid plates 7. The ball joint 4 and a plurality of the negative stiffness compression springs 17 are arranged in the first groove, and each of the plates The upper ends of the negative stiffness compression springs 17 are fixedly connected to the bottom wall of the first groove and the lower ends are connected to the first seat plate 21. Each of the negative stiffness compression springs 17 is in a compressed state. The upper end of the ball joint 4 is fixedly connected to the bottom wall of the first groove, and the lower end of the ball joint 4 extends into the second groove at the top of the first seat plate 21. The lower end of the ball joint 4 is rotatably connected to the first seat plate 21. There are multiple cables and these cables surround the rigid-flexible assembly 20, which can protect the rigid-flexible assembly 20 and effectively prevent the separation of the elastic plate 6 and the rigid plate 7 of the rigid-flexible assembly 20; each cable is in a pre-tensioned state, and the upper and lower ends of each cable are respectively connected to the upper structure connecting plate 1 and the first seat plate 21.

[0036] The superstructure connecting plate 1 is rigidly connected to the building's superstructure (such as a bridge beam or building superstructure) via high-strength bolts, ensuring a secure connection between the device and the building's superstructure and enabling efficient force transmission. Mounting holes are also provided to facilitate bolt connection with the rigid-flexible assembly 20, forming a tight assembly system. High-strength alloy steel, such as Q345D or 40Cr, is selected for its high yield strength and tensile strength, capable of withstanding heavy loads without deformation, ensuring a reliable and stable connection.

[0037] When the cable 5 structure is in normal working condition, it maintains a pre-tensioned state without affecting the seismic isolation performance of the device; by adjusting the length and pre-tension of the cable body, it is possible to effectively limit the lifting of the adaptive anti-lifting device under different load conditions. One end of the cable is anchored to the first seat plate 21 by an anchor to ensure that the cable body will not slip under the extreme load. The cable 5 can be made of a rope made of high-strength steel wire, such as an 18×7 type steel wire rope (that is, the steel wire rope consists of 18 strands, each strand has 7 steel wires), with the outer layer wrapped in a wear-resistant and corrosion-resistant polyethylene sheath and the interior filled with lubricating grease to ensure that the cable body has high tensile strength, good flexibility and a long service life.

[0038] The ball joint 4 can be made of alloy structural steel, such as 20CrMnTi, which has been carburized and quenched to have high surface hardness, good wear resistance, and strong internal toughness, meeting the use requirements of the ball joint 4 under complex stress conditions.

[0039] The negative stiffness spring 17 can change the equivalent stiffness of the entire adaptive lifting device. For the adaptive lifting device, when the equivalent stiffness decreases, the natural vibration period of the structure will be extended accordingly. Under the action of an earthquake, the difference between the natural vibration period of the structure and the dominant period of seismic motion will affect the response of the structure. When the dominant period of seismic motion is shorter than the natural vibration period of the structure, the seismic force exerted on the structure will be reduced. By introducing the negative stiffness spring 17, the equivalent stiffness of the adaptive lifting device is reduced, thereby effectively extending the natural vibration period of the adaptive lifting device. This greatly reduces the response of the adaptive lifting device during an earthquake, reduces the transfer of seismic energy to the adaptive lifting device and the building superstructure above it, and improves the seismic isolation effect of the building.

[0040] The negative spring 17 dynamically adjusts its stiffness, ensuring the isolation system maintains optimal isolation according to varying load conditions. Under relatively low seismic shaking forces, the stiffness of the negative spring 17 changes relatively little, allowing the isolation system to maintain a moderate stiffness, ensuring structural stability while allowing for a certain amount of deformation to dissipate energy. However, when a strong earthquake causes greater shaking forces, the stiffness of the negative spring 17 decreases further, while its elastic deformation absorbs and dissipates more seismic energy.

[0041] The rigid-flexible assembly 20 is composed of multiple elastic plates 6 and rigid plates 7 alternately stacked and fixedly connected, exhibiting a certain positive stiffness. The negative stiffness spring 17, integrated with the rigid-flexible assembly 20, offsets or neutralizes some of the positive stiffness of the rigid-flexible assembly through its negative stiffness, thereby achieving a moderate overall stiffness for the negative stiffness compensation assembly 3. This interaction allows the stiffness of the entire stiffness compensation assembly 3 to be dynamically adjusted based on actual stress conditions, ensuring its stability while also allowing for reduced stiffness when needed to achieve seismic isolation and anti-lift functions.

[0042] The negative stiffness compensation assembly 3 optimizes the stiffness of the entire system through the unique mechanical properties of the negative stiffness spring 17. This negative stiffness of the negative stiffness spring 17 allows the entire system to better adapt to varying operating conditions under load, reducing the overall stiffness of the system, extending the natural vibration period of the structure, and reducing the transfer of seismic energy. The stiffness of the entire negative stiffness compensation assembly varies dynamically within a certain range based on actual operating conditions.

[0043] The spherical crown 13 can be made of surface-hardened alloy steel, such as nitrided 42CrMo steel, which has high surface hardness and good wear resistance, maintains good toughness inside, can withstand greater pressure and friction, and ensures normal operation under complex stress conditions.

[0044] The cables 5 are in a pre-tensioned state, and multiple cables 5 further connect the first seat plate 21, the rigid-flexible assembly 20 and the upper structure connecting plate 1 into one, which can limit the upper structure connecting plate 1 vertically and horizontally. When the impact causes one end of the first seat plate 21 to rise, the cables 5 at the other end of the first seat plate 21 will directly apply a downward pulling force to the upper structure connecting plate 1 through its tension. The pre-tension increases, and this increased tension will directly apply a downward pulling force to the upper structure connecting plate 1 to resist the lifting of the upper structure connecting plate 1 and help the upper structure connecting plate 1 maintain stability in the horizontal position, thereby reducing the vibration and lifting amplitude of the upper structure connecting plate 1, and converting part of the impact energy into elastic deformation energy of the cables 5, thereby achieving an energy dissipation effect.

[0045] The cable 5 is usually made of a material with a certain elasticity, such as high-strength steel wire. During the impact, the cable 5 will be further stretched and elastically deformed. This elastic deformation can absorb and dissipate part of the impact energy. After the impact, the cable 5 will return to its original shape within its elastic range and dissipate the absorbed energy in the form of heat energy, thereby reducing the impact energy transmitted to the upper structure continuous plate 1. When the cable 5 is stretched by the impact, relative movement will occur between the steel wires inside it and between the steel wires and the rope strands, and this relative movement will cause friction. The friction process will convert part of the mechanical energy into heat energy, thereby consuming the impact energy and reducing the impact of the impact on the entire structure.

[0046] The cable 5 works in conjunction with other components such as the negative stiffness compression spring 17, the rigid-flexible assembly 20, and the ball joint 4. When an impact causes the first seat plate 21 to tilt upward or tend to rise, and the first seat plate 21 squeezes the rigid-flexible assembly 20 and the negative stiffness compression spring 17, the change in tension in the cable 5 affects the stress state of the entire negative stiffness compensation assembly 3, prompting the negative stiffness compensation assembly 3 to better perform its stiffness adjustment and energy dissipation functions, thereby reducing the impact energy transmitted upward to the superstructure connecting plate 1 and the superstructure, further enhancing the energy dissipation effect of the entire device.

[0047] When the lower foundation of a building (such as a highway bridge, railway bridge, or high-rise building) is impacted by a load and the spherical crown 13 slips, the spherical crown 13, which contacts the first seat plate 21 and the second seat plate 22 with convex and concave surfaces, will cause the first seat plate 21 to tilt and one end to lift. The tilted and lifted first seat plate 21 will squeeze the rigid-flexible assembly 20 and the negative stiffness compression spring 17, and the stiffness of the negative stiffness compression spring 17 will decrease as the deformation increases. Under the action of the impact, the tilting and lifting of the first seat plate 21 will further compress the negative stiffness compression spring 17, and its stiffness will dynamically decrease, reducing the stiffness of the entire system. This helps to extend the natural vibration period of the structure and reduce the upward transmission of impact energy, thereby reducing the vibration amplitude of the upper structure connecting plate and maintaining its horizontal state. The negative stiffness compression spring 17 absorbs and dissipates part of the impact energy during the compression process. Through the elastic deformation of the negative stiffness compression spring 17, the impact kinetic energy is converted into the elastic potential energy of the negative stiffness compression spring 17, and gradually dissipated in the subsequent vibration process, thereby reducing the impact energy transmitted to the upper structure connection plate, reducing its vibration and displacement, and helping to maintain the horizontal position of the upper structure connection plate 1. The negative stiffness compression spring 17 works in conjunction with the ball joint 4, cable 5 and other components. The ball joint 4 allows the first seat plate 21 to produce limited rotation under impact. Through the coordination of the negative stiffness compression spring 17, the rigid-flexible assembly 20, the ball joint 4 and the cable 5 and other structures, the impact of the load impact on the upper structure connection plate 1 is reduced, thereby reducing the vibration and lifting of the upper structure connection plate 1, so that the upper structure connection plate 1 can continue to remain horizontal and not lift, and basically will not affect the upper structure of the building.

[0048] Therefore, the adaptive anti-lifting device of the present invention can effectively offset and weaken the impact and load transmitted from the bottom up to the lower foundation of the building, so that the upper structure connecting plate 1 will not shake, tilt or lift significantly, thereby affecting the stability of the upper structure of the building.

[0049] Furthermore, the first seat plate 21 includes an adaptive swing block 8, a middle connecting plate 9, an upper curved sliding connecting plate 11 and an upper curved sliding layer 12, which are arranged in sequence from top to bottom and fixedly connected together. The edges of the middle connecting plate 9 respectively exceed the edges of the adaptive swing block 8 and the edges of the upper curved sliding connecting plate 11. The lower ends of each of the cables are respectively fixedly connected to the middle connecting plate, and the first concave spherical surface is arranged at the bottom of the upper curved sliding layer 12.

[0050] The adaptive swing block 8, located at the top of the first seat plate 21, can make certain adaptive adjustments based on the swing tendency of the superstructure under loads such as earthquakes, allowing the entire device to better coordinate with the movement of the superstructure. The edge of the middle connecting plate 9 extends beyond the edges of the adaptive swing block 8 and the upper curved sliding connecting plate 11. This design facilitates the connection of the cables, the lower ends of which can be fixedly connected to the middle connecting plate 9, thereby more tightly connecting the superstructure connecting plate 1 and the first seat plate 21 through the cables, enhancing the stability of the overall structure. The upper curved sliding connecting plate 11 and the upper curved sliding layer 12 are in contact with the bottom of the spherical crown 13. The bottom of the upper curved sliding layer 12 is provided with a first concave spherical surface, which cooperates with the first convex spherical surface at the top of the spherical crown 13 to form a stable sliding friction pair, ensuring that the spherical crown 13 can slide smoothly in the horizontal direction, achieving the seismic isolation function.

[0051] The middle connecting plate 9 can be made of the same high-strength alloy steel as the upper connecting plate to ensure sufficient strength and rigidity and to reliably transmit and distribute the load.

[0052] The provision of the upper curved sliding connecting plate 11 and the upper curved sliding layer 12 further optimizes the sliding friction conditions of the friction pendulum isolation bearing 2. The first concave spherical surface at the bottom of the upper curved sliding layer 12 fits tightly against the first convex spherical surface at the top of the spherical crown 13. Under horizontal loads such as earthquakes, the spherical crown 13 can slide smoothly on this sliding surface, reducing energy loss and improving the isolation effect. This layered structure also facilitates the selection of appropriate materials and surface treatment processes based on specific needs. For example, using a low-friction material in the upper curved sliding layer 12 further reduces frictional resistance, enhances isolation performance, and better protects the structure from the impact of seismic energy.

[0053] The upper curved sliding connecting plate 11 can be made of stainless steel, such as 304 stainless steel, which has good corrosion resistance and strength, can be used for a long time in harsh environments such as ocean and humidity, and ensures the reliability and stability of the connection.

[0054] The upper surface of the upper curved sliding layer 12 is connected to the upper curved sliding connecting plate 11 by an embedded or adhesive connection. The lower surface and the spherical cap 13 are surface-treated with a low-friction coating (such as a molybdenum disulfide coating), forming a good sliding contact interface and reducing sliding resistance. High-strength nylon material is used, which has excellent self-lubrication, wear resistance, and corrosion resistance. It can maintain good performance during long-term sliding, reduce wear, and extend service life.

[0055] Furthermore, the adaptive swing block 8 includes a polytetrafluoroethylene block and a stainless steel block arranged from top to bottom and fixedly connected together, and the second groove is provided on the polytetrafluoroethylene block.

[0056] The PTFE block has excellent self-lubricating properties and a low coefficient of friction, effectively reducing frictional resistance between contacting components and making the adaptive swing block 8 more flexible and adaptable when adjusting its posture. The stainless steel block, on the other hand, possesses high strength and rigidity, providing sufficient support and stability for the entire adaptive swing block 8, preventing it from excessive deformation when subjected to force. Furthermore, a second groove is provided in the PTFE block, which mates with the lower end of the ball joint 4 to form a low-friction rotational connection. This further enhances the vertical and lateral rotational flexibility of the first seat plate 21, helping the device better adapt to structural deformation and movement requirements.

[0057] The use of polytetrafluoroethylene blocks significantly reduces the frictional resistance experienced by the adaptive swing block 8 during its swinging process, enabling it to more sensitively respond to the changes in the movement of the first seat plate 21. Under loads such as earthquakes, the movement of a building's lower foundation is often complex and variable. The low-friction adaptive swing block 8 can adjust its posture promptly and accurately, allowing the entire adaptive anti-lift device to better coordinate with the movement of the building's lower foundation, thereby enhancing the seismic isolation and anti-lift effects.

[0058] The use of stainless steel blocks ensures that the adaptive swing block 8, while maintaining low friction, possesses sufficient strength and rigidity to withstand the loads transmitted from the building's lower foundation. Under extreme loads such as earthquakes, the building's lower foundation exerts significant pressure, shear, and additional dynamic effects due to inertia on the adaptive anti-lift device. The stainless steel blocks effectively resist deformation and damage caused by these loads, ensuring the integrity and reliability of the adaptive swing block 8. This ensures that the device maintains stable performance despite long-term loads and frequent movement, preventing damage or deformation of the adaptive swing block 8 from affecting its normal operation.

[0059] Furthermore, the second seat plate 22 includes a lower curved sliding layer 14, a lower curved sliding connecting plate 15 and a lower curved sliding limit seat 16 which are arranged in sequence from top to bottom and fixedly connected together. The second concave spherical surface is arranged on the top of the lower curved sliding layer 14, and the edge of the lower curved sliding limit seat 16 is provided with an annular flange for limiting the sliding stroke of the spherical crown 13.

[0060] A second concave spherical surface is provided on the top of the lower curved sliding layer 14, which cooperates with the second convex spherical surface at the bottom of the spherical crown 13 to form another key sliding friction pair, providing stable support and guidance for the horizontal sliding of the spherical crown 13. The lower curved sliding connecting plate 15 serves as a connection and transition, firmly connecting the lower curved sliding layer 14 to the lower curved sliding stop seat 16. The annular flange provided on the edge of the lower curved sliding stop seat 16 effectively limits the horizontal sliding travel of the spherical crown 13, preventing the spherical crown 13 from sliding off the second seat plate 22 in extreme situations such as severe earthquakes, thereby preventing the adaptive anti-lift device from losing its function or even causing structural damage.

[0061] The cooperation between lower curved sliding layer 14 and the bottom of spherical crown 13 provides a solid foundation for the seismic isolation function of friction pendulum isolation bearing 2. Its excellent sliding performance and fit ensure that spherical crown 13 slides smoothly under the action of horizontal seismic forces, effectively extending the natural vibration period of the structure and reducing the transfer of seismic energy to the structure.

[0062] The annular flange on the lower curved sliding limit seat 16 is a key safety feature. In extreme earthquakes, when the earthquake intensity exceeds expectations or the structure is subjected to other abnormal loads, the spherical crown 13 may experience significant sliding displacement. The annular flange effectively limits the sliding range of the spherical crown 13, preventing it from slipping off the second seat plate 22 and ensuring that the adaptive anti-lift device maintains a reliable connection with the building's lower foundation. This prevents the serious consequences of the spherical crown 13 slipping out, such as failure of the adaptive anti-lift device and damage to the structural support system, greatly improving the safety of the structure in extreme conditions.

[0063] The upper surface of lower curved sliding layer 14 contacts and mates with spherical crown 13, while its lower surface is connected to lower curved sliding connecting plate 15 via an embedded or adhesive connection, ensuring a tight connection and reliable force transmission during sliding. Like upper curved sliding layer 12, it can be made of high-strength nylon material to ensure excellent sliding performance and wear resistance, suitable for long-term sliding operation.

[0064] The lower curved sliding connecting plate 15 can be made of the same stainless steel material as the upper curved sliding connecting plate 11 to ensure corrosion resistance and strength, adapt to different use environments, and ensure reliability and long-term stability of the connection.

[0065] The lower curved surface sliding limit seat 16 can be made of high-strength cast iron, such as HT300, which has high hardness and wear resistance, can withstand large pressure and friction, and ensure the reliability and stability of the limit function.

[0066] Furthermore, the first groove is located in the middle of the rigid-flexible assembly 20, and the negative stiffness compression spring 17 surrounds the ball joint 4. This layout design allows the negative stiffness compression spring 17 to be evenly distributed around the ball joint 4, so that when subjected to force, it can more evenly apply elastic force to the ball joint 4 and the first seat plate 21 connected thereto. At the same time, setting the first groove in the middle of the rigid-flexible assembly 20 is conducive to ensuring the overall stability and symmetry of the rigid-flexible assembly 20 when subjected to force, so that the rigid-flexible assembly 20 can better exert its mechanical properties of both rigidity and flexibility, and coordinate the transmission and balance of force between the negative stiffness compensation component 3 and the friction pendulum isolation support 2.

[0067] The arrangement of the negative stiffness compression spring 17 surrounding the ball joint 4 allows forces in all directions to be evenly transmitted to the ball joint 4 and the first seat plate 21 through the spring during operation of the device. This avoids local stress concentration or excessive deformation caused by uneven force distribution, and improves the stability and reliability of the entire negative stiffness compensation component 3 and the friction pendulum isolation bearing 2 connected thereto. For example, under the action of multi-directional composite loads caused by an earthquake, the negative stiffness compression spring 17 surrounding the ball joint 4 can provide support forces in multiple directions at the same time, allowing the device to stably resist various complex forces, reduce shaking and offset, and ensure structural safety.

[0068] Placing the first groove in the middle of the rigid-flexible assembly 20 optimizes the mechanical properties of the entire assembly. When subjected to forces from above and below, the rigid-flexible assembly 20 efficiently transmits and distributes the forces through the appropriate deformation and synergistic action of the elastic plate 6 and the rigid plate 7, achieving negative stiffness compensation. This symmetrical and uniform structural layout helps fully realize the potential of the rigid-flexible assembly 20, improving its load-bearing capacity and ability to adapt to varying loads. This enhances the mechanical properties of the entire device and better meets the stringent structural performance requirements of engineering practice.

[0069] Furthermore, the lower end of the ball joint 4 is rotationally connected to the first seat plate 21 by contacting a spherical surface, an ellipsoidal surface or an 8-shaped curved surface. This diverse selection of contact methods provides a flexible design solution for the connection between the ball joint 4 and the first seat plate 21, which can be optimized according to different engineering requirements and force characteristics. The spherical contact method can provide a full range of rotational freedom, allowing the first seat plate 21 to rotate relatively freely in space; the ellipsoidal contact can limit the rotation range to a certain extent while still allowing necessary posture adjustments; the 8-shaped curved surface contact has unique mechanical properties and motion trajectories, which are suitable for specific force modes and motion requirements. Different contact methods can ensure good fit and force transmission efficiency between the ball joint 4 and the first seat plate 21, ensuring the reliability and stability of the rotational connection.

[0070] Furthermore, a plurality of first ear plates 10 are provided on the first seat plate 21 , and a second ear plate 18 is provided on the second seat plate 22 at a position corresponding to each of the first ear plates 10 .

[0071] The first and second lugs 10, 18 provide a convenient interface for installation, connection, and transportation. During transportation, the first and second lugs 10, 18 can be bolted together to prevent shaking and shifting during transport. When used in high-intensity areas, the bolts on the first and second lugs 10, 18 act as shear members, breaking when the impact force reaches a certain level. Furthermore, the second lug 18 can also be used to connect to the building's lower foundation, ensuring that the second base plate 22 does not shift or loosen during use.

[0072] The first ear plate 10 and the second ear plate 18 can be made of cast steel, such as ZG270-500, which has good casting performance and comprehensive mechanical properties, can withstand large loads and complex stress states, and ensure the reliability of the connection.

[0073] A third lug plate 19 may be provided on the side of the upper curved sliding connecting plate 11, and a high-strength bolt may be passed through the third lug plate 19 and connected to the middle connecting plate 9, thereby achieving a fixed connection between the upper curved sliding connecting plate 11 and the middle connecting plate 9. Of course, the upper curved sliding connecting plate 11 and the middle connecting plate 9 may also be fixedly connected together by welding.

[0074] Furthermore, the rigid plates 7 are made of high-strength alloy steel, and the elastic plates 6 are made of rubber. Any adjacent rigid plates 7 and elastic plates 6 are bonded together with an adhesive and then fixed together by riveting. The rubber of some elastic plates 6 on the upper part of the rigid-flexible assembly 20 can be natural rubber or chloroprene rubber, which has good elastic deformation ability and aging resistance, can produce large elastic deformation under load, and provide elastic restoring force. Some rigid plates 7 on the upper part of the rigid-flexible assembly 20 can be made of high-quality carbon structural steel, such as No. 45 steel, which has been heat-treated to increase hardness and strength, has good machinability and load-bearing capacity, and can effectively transmit and distribute loads. Some elastic plates 6 on the lower part of the rigid-flexible assembly 20 can be made of nitrile rubber, which has good oil resistance, wear resistance, and aging resistance. It can produce moderate elastic deformation under load, play a buffering and energy-consuming role, and further absorb structural vibration energy. Some rigid plates 7 at the bottom of the rigid-flexible assembly 20 can be made of low-alloy high-strength structural steel, such as Q390, which has high strength and good plasticity and toughness, can withstand large loads, and provide a stable support platform for the adaptive swing block 8.

[0075] High-strength alloy steel possesses excellent strength and toughness, capable of withstanding significant loads and impacts, providing sufficient rigid support for the entire rigid-flexible assembly 20. The rubber elastic plate 6, possessing excellent elasticity and damping properties, can deform significantly and absorb some energy when subjected to stress, while also providing elastic recovery. The dual fixing method of adhesive bonding and rivet fastening ensures a tight bond between the plates while also withstanding significant shear and tensile forces, ensuring that the rigid-flexible assembly 20 will not experience interlayer separation or shifting even under long-term use and complex stress conditions.

[0076] The combination of alloy steel and rubber gives the rigid-flexible assembly 20 the advantages of high strength, high rigidity, and excellent elasticity. When faced with complex loads such as earthquakes, the rigid plate 7 bears the primary load and pressure, maintaining the shape and stability of the entire assembly, while the elastic plate 6 absorbs some of the energy through deformation, mitigating the impact and reducing the structural vibration response. This balance of rigidity and flexibility enables the device to better adapt to varying loads, enhancing seismic isolation and anti-lift effects.

[0077] The combination of adhesive bonding and rivet connection ensures a secure and reliable connection between the rigid plate 7 and the elastic plate 6. During long-term use, even under frequent vibration and deformation, the plates maintain a good bond without loosening or cracking, thereby ensuring the integrity and mechanical stability of the rigid-flexible assembly 20 and extending the service life of the device.

[0078] Furthermore, the rigid-flexible assembly 20 utilizes elastic plates 6 at both the top and bottom. This design allows the top and bottom elastic plates 6 to deform first when the device is subjected to loads from above and below, providing a buffering and energy absorption effect, reducing the impact of rigid impact on the entire assembly. Furthermore, the deformation of the elastic plates 6 provides a certain amount of adjustable space for the negative stiffness compensation assembly 3, enabling it to better adapt to load changes and achieve adaptive adjustment.

[0079] The elastic plates 6 at the top and bottom can effectively absorb and dissipate energy impacts from the upper and lower directions, such as vertical vibrations caused by earthquakes, forces generated by changes in the structure's own weight, etc. This helps to reduce the vibration energy transmitted to the building structure, reduce the response amplitude of the structure, and improve the comfort and safety of the structure. The deformation ability of the elastic plate 6 allows the negative stiffness compensation component 3 to have a larger adjustment range and flexibility when responding to load changes. Under different operating conditions, the elastic plate 6 can deform accordingly according to the actual stress conditions, and cooperate with other components to achieve more accurate stiffness compensation and adjustment, thereby better meeting the structure's requirements for stability and seismic isolation performance.

[0080] According to another aspect of the present invention, there is also provided an anti-lifting method of an adaptive anti-lifting device based on negative stiffness compensation, comprising the following steps:

[0081] 1) The upper structure connecting plate 1 is fixedly installed on the upper structure of a building, and the second seat plate 22 is fixedly installed on the lower structure of the building, wherein the building is a highway bridge, a railway bridge or a high-rise building;

[0082] 2) When the lower structure of the building is impacted by a horizontal load, the second convex surface of the spherical crown 13 slides on the second concave surface of the second seat plate 22, while the first seat plate 21 rotates relative to the ball joint 4 and one end of the first seat plate 21 is lifted, causing the first seat plate 21 to tilt. The tilted first seat plate 21 squeezes the rigid-flexible assembly 20 and the negative stiffness compression spring 17, thereby reducing the impact of the horizontal load on the upper structure connecting plate 1, thereby reducing the vibration and lifting of the upper structure connecting plate 1.

[0083] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An adaptive anti-lifting device based on negative stiffness compensation, characterized in that: The invention comprises a friction pendulum isolation bearing and a negative stiffness compensation component, wherein the friction pendulum isolation bearing comprises a first seat plate, a spherical crown, and a second seat plate arranged in sequence from top to bottom, wherein the bottom of the first seat plate is provided with a first concave spherical surface, the top of the spherical crown is provided with a first convex spherical surface in contact with the first concave spherical surface, the top of the second seat plate is provided with a second concave spherical surface, and the bottom of the spherical crown is provided with a second convex spherical surface in contact with the second concave spherical surface, wherein: The negative stiffness compensation component includes an upper structure connecting plate, a rigid-flexible assembly, a negative stiffness compression spring, a ball joint and a cable. The rigid-flexible assembly is located between the upper structure connecting plate and the first seat plate and is fixedly connected to the upper structure connecting plate and the first seat plate respectively. The rigid-flexible assembly includes a plurality of plates stacked and fixedly connected together. These plates include a plurality of elastic plates and a plurality of rigid plates, and the elastic plates and the rigid plates are arranged alternately. A first groove is provided at the bottom of the rigid-flexible assembly, and the bottom wall of the first groove is a part of the bottom surface of one of the rigid plates. The ball joint and There are multiple negative stiffness compression springs, the upper end of each negative stiffness compression spring is fixedly connected to the bottom wall of the first groove and the lower end is connected to the first seat plate, each negative stiffness compression spring is in a compressed state, the upper end of the ball joint is fixedly connected to the bottom wall of the first groove, the lower end of the ball joint extends into the second groove at the top of the first seat plate, and the lower end of the ball joint is rotatably connected to the first seat plate. There are multiple cables and these cables surround the rigid-flexible assembly, each cable is in a pre-tensioned state, and the upper and lower ends of each cable are respectively connected to the upper structure connecting plate and the first seat plate.

2. The adaptive anti-lifting device based on negative stiffness compensation according to claim 1, characterized in that: The first seat plate includes an adaptive swing block, a middle connecting plate, an upper curved sliding connecting plate and an upper curved sliding layer, which are arranged in sequence from top to bottom and fixedly connected together. The edges of the middle connecting plate extend beyond the edges of the adaptive swing block and the edges of the upper curved sliding connecting plate respectively. The lower end of each of the cables is fixedly connected to the middle connecting plate respectively. The first concave spherical surface is arranged at the bottom of the upper curved sliding layer.

3. The adaptive anti-lifting device based on negative stiffness compensation according to claim 2, characterized in that: The adaptive swing block includes a polytetrafluoroethylene block and a stainless steel block which are arranged from top to bottom and fixedly connected together, and the second groove is provided on the polytetrafluoroethylene block.

4. The adaptive anti-lifting device based on negative stiffness compensation according to claim 1, characterized in that: The second seat plate includes a lower curved sliding layer, a lower curved sliding connecting plate and a lower curved sliding limit seat which are arranged in sequence from top to bottom and fixedly connected together. The second concave spherical surface is arranged on the top of the lower curved sliding layer, and the edge of the lower curved sliding limit seat is provided with an annular flange for limiting the sliding stroke of the spherical crown.

5. The adaptive anti-lifting device based on negative stiffness compensation according to claim 1, characterized in that: The first groove is located in the middle of the rigid-flexible assembly, and the negative stiffness compression spring surrounds the ball joint.

6. The adaptive anti-lifting device based on negative stiffness compensation according to claim 1, characterized in that: The lower end of the ball joint is rotationally connected to the first seat plate by contacting a spherical surface, an ellipsoidal surface or an 8-shaped curved surface.

7. The adaptive anti-lifting device based on negative stiffness compensation according to claim 1, characterized in that: The first seat plate is provided with a plurality of first lug plates, and the second seat plate is provided with a second lug plate at a position corresponding to each of the first lug plates.

8. The adaptive anti-lifting device based on negative stiffness compensation according to claim 1, characterized in that: The rigid plates are made of high-strength alloy steel, and the elastic plates are made of rubber. Any adjacent rigid plates and elastic plates are bonded with an adhesive and then fixed together by rivets.

9. The adaptive anti-lifting device based on negative stiffness compensation according to claim 1, characterized in that: The top and bottom of the rigid-flexible assembly are both made of elastic plates.

10. An anti-lifting method of an adaptive anti-lifting device based on negative stiffness compensation, characterized in that: The following steps are involved: 1) The upper structure connecting plate is fixedly installed on the upper structure of a building, and the second seat plate is fixedly installed on the lower structure of the building, wherein the building is a highway bridge, a railway bridge or a high-rise building; 2) When the lower structure of the building is impacted by a horizontal load, the second convex surface of the spherical crown slides on the second concave surface of the second seat plate, while the first seat plate rotates relative to the ball joint and one end of the first seat plate is lifted, causing the first seat plate to tilt. The tilted first seat plate squeezes the rigid-flexible assembly and the negative stiffness compression spring, thereby reducing the impact of the horizontal load on the upper structure connecting plate, thereby reducing the vibration and lifting of the upper structure connecting plate.

Images