High-energy-consumption anti-falling beam support with horizontal variable stiffness

Abstract

The invention relates to the technical field of bridge structures, in particular to a high-energy-consumption anti-falling beam support with horizontal variable stiffness, which mainly comprises an upper seat plate, a middle seat plate and a lower seat plate. The lower seat plate is provided with a continuous variable curvature track formed by smooth transition connection of at least two sections of arc-shaped curved surfaces with different curvatures, and the edge of the lower seat plate is provided with a flexible limiting area. The middle seat plate is of a double-convex-spherical-surface structure, chamfers are arranged on the edge of the middle seat plate, and the middle seat plate and the flexible limiting area are matched in a surface contact mode to achieve limiting. The horizontal equivalent stiffness of the support can be continuously and adaptively adjusted according to the displacement through the sliding of the middle seat plate along the continuous variable curvature track. The variable curvature, high energy consumption and integrated flexible anti-falling beam functions are integrated in a simple structure, the problems that a traditional fixed curvature support is single in performance and an existing variable curvature support is complex in structure are solved, and the variable curvature support has the advantages of being high in self-adaption, safe, reliable, economical, durable and the like.

Description

Technical Field

[0001] This invention relates to the field of bridge structure technology, and more specifically, to a high-energy-dissipating anti-fall beam support with horizontal variable stiffness. Background Technology

[0002] In civil engineering fields such as bridges and buildings, structural safety and durability are always core design considerations. Dynamic loads such as earthquakes and wind loads can easily induce strong vibrations in engineering structures, which, if not handled properly, can lead to structural damage or even catastrophic failure. Among numerous structural seismic isolation and control technologies, friction pendulum bearings are highly favored due to their clear mechanism and significant effects. Their core working principle involves converting kinetic energy into frictional heat energy through the relative motion between the superstructure and the bearing's sliding surface, while simultaneously utilizing the geometric properties of the spherical surface to provide the structure with self-resetting capability, thereby effectively reducing the seismic forces transmitted to the substructure.

[0003] Traditional friction pendulum bearings typically employ a fixed-curvature arc-shaped sliding surface design. Their seismic isolation performance, especially their natural period and energy dissipation efficiency, is determined during the design phase by a few parameters, such as the radius of curvature and friction coefficient of the sliding surface. This "one-parameter-determined" design approach has demonstrated good adaptability to earthquakes with specific spectral characteristics. However, the load conditions faced by structures in actual engineering are highly complex and uncertain. Earthquakes of different intensities and spectral characteristics, and even common wind loads, place significantly different performance requirements on the bearings. The fixed curvature friction pendulum bearing thus reveals its inherent limitations: when encountering minor earthquakes or frequent wind loads, the large curvature radius designed to achieve better seismic isolation results in a low initial stiffness of the bearing, making it difficult to effectively control the displacement response of the structure under normal use conditions, affecting driving comfort and building structural stability; while when encountering rare strong earthquakes, the fixed curvature radius makes it difficult to further optimize energy dissipation efficiency, which may lead to excessively high contact stress on the sliding surface, accelerated wear, and even affect the bearing's crucial self-resetting performance, bringing great difficulties and economic losses to post-earthquake repair.

[0004] As modern engineering structures develop towards larger spans and higher flexibility, higher demands are placed on the adaptive capabilities of seismic isolation bearings. To overcome the performance bottleneck of fixed-curvature bearings, the industry has begun exploring variable-curvature friction pendulum bearings. For example, existing patent CN221000588U discloses a variable-curvature friction pendulum bearing for preventing beam fall. This utility model, by setting an upper support plate, a spherical crown, a middle plate, and a lower support plate, and making the curvature radii of the upper, middle, and lower spherical sliding plates different, attempts to provide different isolation periods through the combination of multiple fixed-curvature sliding surfaces to avoid resonance. The design idea is to use different layers of sliding surfaces to cope with different working conditions, but the curvature of each sliding surface itself remains constant. This "discrete" variable curvature method may not result in smooth stiffness changes during working condition transitions, and there is still a risk of local stress concentration or discontinuous motion in the junction areas of different curvature sliding surfaces. Furthermore, this scheme relies on the coordinated work of multiple sliding surfaces, resulting in a relatively complex structure and high requirements for manufacturing and assembly precision.

[0005] Existing patent CN103243644B discloses a variable curvature adaptive friction pendulum type seismic isolation bearing. The core of this patent lies in a spherical base with continuously variable curvature (such as a hyperbolic curve or elliptic curve), and several slider assemblies embedded in grooves densely distributed on the spherical surface under a double-spherical liner. These slider assemblies contain deformable material that adapts to the continuous change in the curvature of the base through compression or rotation, aiming to achieve adaptive contact of the friction surface and avoid stress concentration. Simultaneously, a combination of limiting plates, shear bolts, and wire ropes achieves the function of preventing beam fall. However, this technology still has significant shortcomings: First, the variable curvature is achieved through continuous increases in the base, making it difficult to accurately match the differentiated stiffness requirements under minor and strong earthquakes, and failing to achieve dynamic adaptation of "increasing stiffness under minor earthquakes and optimizing energy consumption under strong earthquakes"; Second, the slider assembly has a complex structure, including multiple components such as deformation blocks, multi-layer liners, and sealing rings, which not only increases manufacturing costs but may also affect long-term durability due to component wear; Third, the anti-fall beam relies on a combination design of limiting plates and wire ropes, lacking an integrated anti-fall beam dedicated structure, and does not consider the need for rapid reset after the beam falls, making post-disaster repair difficult; Fourth, the combination of double spherical liners and slider assemblies has limited adaptability to the vibration characteristics of large-span structures, making it difficult to balance the normal use stability and seismic safety of highly flexible structures.

[0006] In summary, while existing variable curvature or graded damping bearings represent a step forward in addressing the limitations of fixed curvature bearings, they still face the following key technical bottlenecks: First, the implementation of variable curvature is complex, relying either on a continuously variable curvature base and complex slider components, or employing a distributed multi-slide plate structure, making it difficult to accurately adapt to stiffness requirements under different load intensities and achieve adaptive optimization under multiple working conditions; second, the design of anti-fall beam structures lacks integrated design, resulting in redundant and complex structures, or the presence of rigid impact hazards, leading to insufficient reliability and durability; third, the need for rapid repositioning after beam fall is generally not considered, resulting in high post-disaster repair costs and low efficiency.

[0007] Therefore, there is an urgent need to develop a variable curvature friction pendulum bearing that can pre-set different curvature parameters according to load characteristics to optimize seismic isolation performance under different working conditions, so as to provide a more efficient and reliable technical solution for improving the seismic safety and long-term durability of engineering structures. Summary of the Invention

[0008] In view of this, the present invention aims to propose a high-energy-dissipating anti-fall beam support with horizontal variable stiffness, so as to solve the problems in the prior art that traditional fixed curvature friction pendulum supports are difficult to adaptively adjust stiffness and energy dissipation performance according to load intensity, and the variable curvature implementation method of some variable curvature friction pendulum supports is complicated.

[0009] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0010] This invention provides a high-energy-dissipating anti-fall beam support with horizontal variable stiffness, comprising:

[0011] The lower seat plate has a second concave spherical surface, which is a continuous variable curvature track formed by the smooth transition and connection of at least two arc surfaces with different curvatures; the lower seat plate has a flexible limiting area.

[0012] The middle seat plate has a chamfered edge, and the chamfer and the flexible limiting area are limited by surface contact; and the anti-fall beam support slides on the continuously variable curvature track through the middle seat plate.

[0013] Furthermore, the curvature of the second concave spherical surface of the lower seat plate continuously increases or decreases from the center outwards along its continuously variable curvature track.

[0014] Furthermore, when the middle seat plate slides to the edge limit position of the continuously variable curvature track, the chamfer and the flexible limiting area form surface contact.

[0015] Furthermore, the middle seat plate has a double convex spherical structure, with the upper surface being the first convex spherical surface and the lower surface being the second convex spherical surface.

[0016] Furthermore, the anti-fall beam support also includes a lower spherical stainless steel sliding plate fixed to the second concave spherical surface of the lower seat plate, and a lower spherical non-metallic sliding plate fixed to the second convex spherical surface of the middle seat plate; the lower spherical non-metallic sliding plate and the lower spherical stainless steel sliding plate constitute a second friction pair.

[0017] Furthermore, the lower spherical non-metallic sliding plate is integrally embedded in the groove opened in the second convex spherical surface of the middle seat plate, and smoothly transitions with the second convex spherical surface of the middle seat plate, with the roughness Ra ≤ 1.0 μm at the transition point.

[0018] Furthermore, the anti-fall beam support also includes an upper seat plate, the lower surface of which is provided with a first concave spherical surface with a fixed curvature.

[0019] Furthermore, the anti-fall beam support also includes an upper spherical stainless steel sliding plate fixed to the first concave spherical surface of the upper seat plate, and an upper spherical non-metallic sliding plate fixed to the first convex spherical surface of the middle seat plate; the upper spherical non-metallic sliding plate and the upper spherical stainless steel sliding plate constitute the first friction pair.

[0020] Furthermore, sealing rings are provided between the upper and middle bearing plates of the anti-fall beam support, and between the lower and middle bearing plates.

[0021] Furthermore, the curvature of the lower spherical non-metallic slide plate is the same at the initial position of the continuously variable curvature track on the lower spherical stainless steel slide plate; the curvature of the upper spherical non-metallic slide plate is the same as that of the upper spherical stainless steel slide plate.

[0022] Compared with existing technologies, the high-energy-dissipating anti-fall beam support with horizontal variable stiffness described in this invention has the following advantages:

[0023] (1) Achieving true horizontal adaptive variable stiffness, with performance intelligently matched to seismic intensity. This invention, by setting a sliding track with continuously changing curvature on the lower plate, enables the horizontal equivalent stiffness of the anti-fall beam support to continuously and smoothly decrease automatically as the slider displacement increases. This mechanism fundamentally solves the inherent contradiction of the traditional fixed curvature anti-fall beam support, which is "one parameter determines its life": under minor earthquakes or wind loads, the small radius of the track center provides higher initial stiffness, effectively controlling the displacement; under strong earthquakes, the large radius of the track outer side provides lower stiffness and extends the structural period, achieving efficient seismic isolation and energy dissipation. Its stiffness change process is completely passive and adaptive, requiring no external intervention, achieving precise dynamic adaptation of "increasing stiffness under minor earthquakes and optimizing energy dissipation under strong earthquakes";

[0024] (2) A new integrated flexible anti-fall beam structure has been created, significantly improving safety and reliability. This invention utilizes the chamfer of the edge of the middle seat plate and the flexible limiting area of ​​the track edge of the lower seat plate to directly cooperate. Under rare earthquakes, this design achieves flexible limiting through progressive surface contact, converting the huge impact energy into distributed stress and frictional heat, effectively avoiding the instantaneous impact peak, component damage, and stress concentration caused by rigid collisions. This not only prevents beam fall from the root but also protects the main structure of the support and the lower pier, and ensures smooth and automatic reset after the earthquake, achieving the dual goals of safety protection and structural protection;

[0025] (3) Highly integrated and simplified structure, balancing excellent performance and superior economy. This invention highly integrates four major functions—sliding, variable stiffness, energy dissipation, and limiting—into a core module of "variable curvature track + chamfer," resulting in an extremely simple structure. Compared to existing variable curvature supports, this invention significantly reduces the number of parts, clarifies assembly relationships, and achieves significant weight reduction. Attached Figure Description

[0026] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0027] Figure 1 This is a schematic diagram of the anti-fall beam support described in this invention;

[0028] Figure 2 For the present invention Figure 1 Enlarged view of the structure of part A in the middle;

[0029] Figure 3 This is a top view of the anti-fall beam support described in this invention.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Upper seat plate; 2. Upper spherical stainless steel sliding plate; 3. Upper spherical non-metallic sliding plate; 4. Upper spherical sealing ring; 5. Middle seat plate; 6. Lower spherical stainless steel sliding plate; 7. Lower seat plate; 8. Lower spherical sealing ring; 9. Lower spherical non-metallic sliding plate; 10. Chamfer; 11. Flexible limiting area; 12. First concave spherical surface; 13. First convex spherical surface; 14. Second convex spherical surface; 15. Second concave spherical surface. Detailed Implementation

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In addition, the orientations involved in the following specific embodiments are briefly explained: the directions or positional relationships indicated by "front", "rear", "up", "down", "left", "right", "top", "bottom", etc. mentioned in the embodiments refer to the orientations or positional relationships shown in the accompanying drawings, and the term "on" means directly or indirectly supported by the element.

[0033] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] This invention discloses a high-energy-dissipating anti-fall beam support with horizontal variable stiffness, comprising:

[0035] The lower seat plate 7 is provided with a second concave spherical surface 15, which is a continuous variable curvature track formed by the smooth transition and connection of at least two arc surfaces with different curvatures; the lower seat plate 7 is provided with a flexible limiting area 11.

[0036] The middle seat plate 5 has a chamfer 10 on its edge. The chamfer 10 and the flexible limiting area 11 are limited by surface contact. The anti-fall beam support slides on the continuously variable curvature track through the middle seat plate 5.

[0037] Preferably, the lower seat plate 7 is integrally forged from high-strength structural steel, and the plate thickness is determined according to the design load requirements of the building structure to ensure the load-bearing strength and structural stability of the building; the middle seat plate 5 is an integrally forged spherical crown structure, with the height to diameter ratio of the spherical crown being 1:3 to 1:5, taking into account both structural strength and lightweight requirements; the chamfer 10 is set circumferentially along the outer edge of the middle seat plate 5, and the flexible limiting area 11 is an integral structural part of the lower seat plate 7, not an additional assembly component, and its processing is completed simultaneously with the second concave spherical surface 15; the flexible limiting area 11 is made of high-strength low-alloy structural steel, such as Q460C or Q690E chromium-molybdenum alloy steel, and a chromium-nickel-molybdenum wear-resistant elastic alloy layer is deposited on the surface of the flexible limiting area 11 to improve its toughness and wear resistance.

[0038] It should be noted that the lower seat plate 7 and the middle seat plate 5 are the core components of the anti-fall beam support of the present invention. The continuous variable curvature track on the lower seat plate 7 provides a preset sliding path for the middle seat plate 5. When the middle seat plate 5 slides along the track from the center to the edge, based on the friction pendulum theory, its horizontal equivalent stiffness smoothly decreases or increases as the curvature of the track continuously decreases or increases. Without the need for additional component switching or manual intervention, it can adaptively match the stiffness requirements of different working conditions such as small earthquakes, moderate earthquakes, rare strong earthquakes and common wind loads, thereby achieving horizontal adaptive variable stiffness. Moreover, the chamfer 10 can guide the middle seat plate 5 to smoothly transition between different curvature sections, avoiding jamming, discontinuous movement or sudden changes in local stress during the sliding process. The flexible limiting zone 11 and the chamfer 10 work together to prevent the beam from falling off. This design is fundamentally different from traditional independent rigid blocks or split limiting devices. The latter usually consume energy and limit the beam through rigid collision or plastic fracture, which is often accompanied by irreversible damage or destruction, and is complicated to replace after an earthquake. This invention uses the constraint force generated by the arc surface fit of the flexible limiting zone 11 and the chamfer 10 and the interface friction to convert the energy of a strong earthquake impact into a more evenly distributed contact stress and frictional heat energy, thereby achieving flexible limiting without rigid impact, recoverable, and high energy consumption. While achieving ultimate protection, it maintains the integrity and resettibility of the main structure of the anti-fall beam support to the greatest extent.

[0039] This invention integrates three major functions—sliding energy dissipation, variable stiffness tuning, and flexible limiting to prevent beam fall—through a continuous variable curvature sliding track and its edge flexible limiting zone 11. Its core value lies in breaking away from the traditional "modular assembly" thinking in the field of bridge bearings, which assigns load-bearing, sliding, and limiting functions to different components. Instead, it pursues the synergy of multiple performances in a single, coherent physical structure, thereby reducing the number of parts and lowering the risk of functional loss due to connection failure or part detachment.

[0040] Specifically, the curvature of the second concave spherical surface 15 of the lower seat plate 7 continuously increases or decreases from the center outwards along its continuously variable curvature track.

[0041] Preferably, the continuous variable curvature track consists of three continuously smooth transition arc surfaces, which are, from the center outwards, a large curvature section, a medium curvature section, and a small curvature section. The large curvature section at the center is suitable for small earthquakes or wind loads with high-frequency vibrations, providing a short-period rapid response. The medium curvature section in the middle is suitable for medium-intensity earthquakes, providing transition stiffness and achieving energy dissipation. The small curvature section on the outer side is suitable for strong earthquakes, extending the isolation period through a large radius to avoid resonance.

[0042] It should be noted that the curvature parameters of the continuously variable curvature track can be flexibly adjusted according to engineering requirements such as bridge span and design seismic intensity; while the curvature variation design strictly follows the friction pendulum theory, that is, the horizontal equivalent stiffness of the support is positively correlated with the curvature of the sliding surface and negatively correlated with the radius of curvature.

[0043] This invention establishes an integrated flexible limiting structure by setting a continuously variable curvature track and a flexible limiting zone 11 on the lower seat plate 7, which cooperates with the chamfer 10 on the middle seat plate 5 to form an integrated flexible limiting structure. This allows the anti-fall beam support to adaptively adjust its horizontal stiffness and energy dissipation capacity according to the load intensity. During minor earthquakes or wind loads, the seat plate 5 is located in the high curvature section, providing higher initial stiffness to control displacement. During strong earthquakes, the slider slides to the low curvature section, significantly reducing stiffness to extend the period and reduce seismic force, and efficiently dissipating energy through large displacement friction.

[0044] Specifically, when the middle seat plate 5 slides to the edge limit position of the continuously variable curvature track, the chamfer 10 and the flexible limiting area 11 form surface contact.

[0045] More specifically, both the chamfer 10 and the flexible limiting area 11 have small curvatures, and the surface contact is a gradual physical process.

[0046] It should be noted that the surface contact between the chamfer 10 and the flexible limiting area 11 does not occur suddenly when the displacement reaches a certain fixed value; when the displacement of the middle seat plate 5 approaches the design limit, the arc surface of the chamfer 10 begins to approach the arc surface of the flexible limiting area 11 infinitely, and the contact area rapidly expands from a point or a line into a contact surface with an ever-increasing area, so that the contact pressure can be dispersed; at the same time, the huge friction force generated by the contact surface directly converts the impact kinetic energy into frictional heat energy and dissipates it.

[0047] Preferably, the surface of the chamfer 10 is treated with a wear-resistant alloy overlay to improve its surface hardness and wear resistance, preventing scratches under high contact pressure. The surface roughness Ra of the flexible limiting area 11 is ≤0.8μm to reduce the coefficient of friction and promote post-vibration recovery.

[0048] The surface contact design of the chamfer 10 and the flexible limiting area 11 transforms the instantaneous collision of the traditional rigid stop into a progressive flexible fit, which can effectively disperse contact stress and ensure that the core sliding component of the anti-fall beam support is not damaged under the extreme state of a major earthquake, thereby reducing the risk of beam falling. Moreover, the smooth curved surface contact allows the middle seat plate 5 to easily detach from the limiting area after an earthquake and automatically return to its original position under the action of self-resetting force, solving the problem of easy jamming of traditional rigid limiting devices.

[0049] Specifically, the middle seat plate 5 has a double convex spherical structure, with its upper surface being a first convex spherical surface 13 and its lower surface being a second convex spherical surface 14; and the anti-fall beam support also includes an upper seat plate 1, the lower surface of which is provided with a first concave spherical surface 12, which has a fixed curvature.

[0050] More specifically, the middle seat plate 5 has a spherical crown structure with a double convex spherical surface. The outer edges of the double convex spherical surface are chamfered. A first groove is machined on the top of the first convex spherical surface 13 of the middle seat plate 5. The upper spherical non-metallic sliding plate 3 is integrally embedded in the first groove by interference fit or bonding. After embedding, the upper surface of the upper spherical non-metallic sliding plate 3 and the ungrooved part of the first convex spherical surface 13 of the middle seat plate 5 are smoothly transitioned to form a complete spherical surface. A second groove is machined on the top of the second convex spherical surface 14 of the middle seat plate 5. The lower spherical non-metallic sliding plate 9 is integrally embedded in the second groove by interference fit or bonding to form a flat and continuous friction surface.

[0051] It should be noted that the centers of the double convex spherical surfaces of the middle seat plate 5 are completely coincident, ensuring balanced force distribution.

[0052] Specifically, the anti-fall beam support also includes a lower spherical stainless steel sliding plate 6 fixed on the second concave spherical surface 15 of the lower seat plate 7, and a lower spherical non-metallic sliding plate 9 fixed on the second convex spherical surface 14 of the middle seat plate 5; the lower spherical non-metallic sliding plate 9 and the lower spherical stainless steel sliding plate 6 constitute a second friction pair.

[0053] More specifically, the anti-fall beam support also includes an upper spherical stainless steel sliding plate 2 fixed to the first concave spherical surface 12 of the upper seat plate 1, and an upper spherical non-metallic sliding plate 3 fixed to the first convex spherical surface 13 of the middle seat plate 5; the upper spherical non-metallic sliding plate 3 and the upper spherical stainless steel sliding plate 2 constitute the first friction pair.

[0054] It should be noted that the lower spherical non-metallic sliding plate 9 is integrally embedded in the groove of the second convex spherical surface 14 of the middle seat plate 5, and smoothly transitions with the second convex spherical surface 14 of the middle seat plate 5, with a roughness Ra ≤ 1.0 μm at the transition point. The curvature of the upper spherical non-metallic sliding plate 3 is the same as that of the upper spherical stainless steel sliding plate 2, ensuring that the two achieve surface contact during rotation, resulting in smooth rotation and uniform stress. The curvature of the lower spherical non-metallic sliding plate 9 is the same as that of the lower spherical stainless steel sliding plate 6 at the initial position of the continuously variable curvature track. This is because the lower spherical non-metallic sliding plate 9 is integrally rigidly embedded in the middle seat plate 5, and its spherical curvature is a fixed value once formed. This design ensures that the second friction pair can achieve optimal surface contact in the initial state and during small displacement sliding of the support. When sliding to other positions on the track, due to the continuous change of the curvature of the lower spherical stainless steel sliding plate 6, the contact will adaptively adjust from completely conformal to locally conformal. However, through the slight elastic deformation of the lower spherical non-metallic sliding plate 9, the contact stress can still be kept within a safe and reasonable range. Therefore, the first friction pair of the present invention mainly undertakes the rotation function and helps to dissipate small vibration energy; the second friction pair is a core interface with horizontal variable stiffness and high energy consumption. When the middle seat plate 5 slides, the lower spherical non-metallic sliding plate 9 and the lower spherical stainless steel sliding plate 6 make dynamic contact with the variable curvature track, and energy is dissipated through the friction of the contact surface.

[0055] Preferably, the upper spherical non-metallic sliding plate 3 and the lower spherical non-metallic sliding plate 9 are made of polytetrafluoroethylene vinyl composite material, which has a low coefficient of friction, high wear resistance and good weather resistance, and can be adapted to the long-term use requirements in different environments; the upper spherical stainless steel sliding plate 2 and the lower spherical stainless steel sliding plate 6 are made of austenitic stainless steel and are precision ground and polished to ensure the flatness and corrosion resistance of the sliding surface. The friction pair formed by the two can maintain stable energy consumption efficiency for a long time.

[0056] The first friction pair focuses on the rotation function, ensuring smooth rotation and uniform contact stress during normal use and minor vibrations of the building structure. It also helps dissipate low-frequency, small-amplitude vibration energy, avoiding interference between rotation requirements and horizontal variable stiffness and high energy consumption functions. The second friction pair, as the core energy dissipation interface, works with the variable curvature track to achieve horizontal variable stiffness and efficient energy dissipation, significantly improving the overall performance of the anti-fall beam support. The optimal surface contact at the initial position of the second friction pair ensures the high stiffness and stability of the support under normal and minor vibrations. During large displacement sliding, the small elastic deformation of the lower spherical non-metallic sliding plate 9 adaptively fits the continuous variable curvature track, avoiding stress concentration or separation caused by rigidity mismatch, and ensuring the continuous and effective friction energy dissipation, enabling the anti-fall beam support to work reliably throughout the entire displacement range.

[0057] Specifically, sealing rings are provided between the upper seat plate 1 and the middle seat plate 5 of the anti-fall beam support, and between the lower seat plate 7 and the middle seat plate 5.

[0058] More specifically, the upper spherical sealing ring 4 installed on the edge of the upper seat plate 1 forms a dynamic seal with the first convex spherical surface 13 of the middle seat plate 5; the lower spherical sealing ring 8 installed on the edge of the lower seat plate 7 forms a dynamic seal with the second convex spherical surface 14 of the middle seat plate 5.

[0059] Preferably, the upper spherical sealing ring 4 and the lower spherical sealing ring 8 are made of aging-resistant rubber material.

[0060] The dynamic sealing of the sealing ring prevents dust, rainwater and other impurities from entering the friction pair and the continuously variable curvature track, avoiding wear, corrosion or jamming of the sliding surface, and significantly improving the service life of the anti-fall beam support.

[0061] Example 1

[0062] like Figures 1 to 3 As shown, this embodiment provides a working process for a high-energy-dissipating anti-fall beam support with horizontal variable stiffness. This variable curvature anti-fall beam support includes three arc surfaces with different curvatures. From the center outwards, the curvature decreases, in the following order: a central high-curvature section, a middle medium-curvature section, and an outer low-curvature section.

[0063] The working process of the variable curvature anti-fall beam support in this invention is as follows:

[0064] Minor earthquake / frequent wind load condition: When the load intensity is low, the middle seat plate 5 carries the lower spherical non-metallic sliding plate 9 to slide on the large curvature section of the lower spherical stainless steel sliding plate 6. This large curvature section has the smallest radius of curvature and can provide high initial stiffness and short isolation period, which can effectively suppress the displacement response of the building structure under frequent minor vibrations and ensure the overall stability of the building structure.

[0065] Moderate to strong earthquake condition: When encountering a moderate earthquake, the earthquake thrust increases. The middle seat plate 5 overcomes the frictional resistance generated by the first and second friction pairs, and the sliding displacement increases. It smoothly transitions to the sliding of the medium curvature section. The curvature of this section decreases and the radius of curvature increases. The equivalent horizontal stiffness of the anti-fall beam support decreases adaptively, effectively prolonging the vibration period of the building structure, avoiding the main earthquake frequency, and rapidly consuming the earthquake input energy through continuous and stable sliding friction.

[0066] Rare strong earthquake condition: When encountering a rare strong earthquake, the load further increases, and the middle seat plate 5 slides to the outer small curvature section, where the radius of curvature is the largest. At this time, the anti-fall beam support reaches the minimum equivalent stiffness, allowing the building structure to produce a large design displacement, thereby maximizing the extension of the period and reducing the seismic force. During this long-stroke sliding, most of the seismic energy is dissipated through friction. At this time, the chamfer 10 and the flexible limiting area 11 of the lower seat plate 7 make close surface contact, generating a strong constraint force, effectively preventing the middle seat plate 5 from detaching from the lower seat plate 7, and achieving the final anti-fall beam function. Moreover, the arc surface of the chamfer 10 and the flexible limiting area 11 is in flexible contact, which can effectively avoid the instantaneous huge impact force and component damage caused by rigid collision.

[0067] Reset capability: After the seismic load disappears, under the action of the self-reset force generated by the spherical geometry and vertical load, the middle seat plate 5 slides in the opposite direction along the original variable curvature track; the chamfer 10 can guide the middle seat plate 5 to smoothly transition between different curvature sections, avoiding jamming or climbing effects during the reset process; finally, under the action of the restoring force, the middle seat plate 5 automatically returns to the initial central small curvature section position, and the bridge structure quickly returns to normal use, demonstrating excellent adaptive reset capability.

[0068] The horizontal adaptive variable stiffness and high energy dissipation mechanism of the anti-fall beam support in this invention is achieved by relying on the continuously variable curvature track on the lower support plate 7. This continuously variable curvature track consists of three smoothly transitioning arcs: a large curvature at the center, a medium curvature in the middle, and a small curvature on the outer side. According to the friction pendulum theory, the horizontal equivalent stiffness of the support is positively correlated with the curvature and negatively correlated with the radius of curvature. When the middle support plate 7 slides from the center of the continuously variable curvature track to the edge, the stiffness decreases smoothly as the curvature decreases, without the need for additional component switching. At the same time, the increased sliding displacement makes the energy dissipation capacity of the friction pair match the energy level of the seismic input, thereby achieving efficient and adaptive dissipation of seismic energy under different load conditions.

[0069] The anti-falling beam function of this invention is achieved through an integrated flexible restraint structure, abandoning the traditional independent rigid stop block. Relying on the dynamic cooperation formed by the chamfer 10 at the edge of the middle seat plate 5 and the flexible restraint area 11 of the lower seat plate 7, in the event of a rare strong earthquake, the chamfer 10 and the flexible restraint area 11 are in close surface contact. The curved surface fit generates restraint force, effectively preventing the middle seat plate 5 from detaching from the lower seat plate 7, thus preventing beam fall at the source. Furthermore, the surface contact design disperses impact stress and protects the integrity of the components. After an earthquake, under the self-resetting force generated by the spherical geometry and vertical load, the chamfer 10 guides the middle seat plate 5 to smoothly slide in the opposite direction along a variable curvature track, quickly returning to its initial position, ensuring rapid post-earthquake structural recovery.

[0070] In summary, this invention discloses a high-energy-dissipating anti-fall beam support with horizontal variable stiffness. Through integrated structural innovation, it integrates three major functions: horizontal adaptive variable stiffness, high energy dissipation, and flexible anti-fall beam. The anti-fall beam support mainly includes a lower support plate 7 with a continuously variable curvature track, a double-convex spherical middle support plate 5 with a chamfer 10, and an upper support plate 1 with a fixed-curvature concave spherical surface. During operation, the middle support plate 5 slides along the preset variable curvature track, and its horizontal stiffness continuously and smoothly decreases automatically as the displacement increases, thus intelligently matching the performance requirements of the structure for earthquakes of different intensities. In this process, it efficiently dissipates seismic energy through sliding friction. When encountering a rare earthquake, the chamfer 10 of the middle support plate 5 forms a progressive surface contact with the flexible limiting area 11 at the edge of the track, achieving impact-free flexible limiting, fundamentally preventing beam fall, and ensuring smooth automatic reset after the earthquake. This invention has a simple and compact structure, abandoning the traditional external stop block, and achieving significant advantages such as adaptive performance, safety and reliability, and low maintenance costs.

[0071] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A high-energy-dissipating anti-fall beam support with horizontal variable stiffness, characterized in that, The anti-fall beam support includes: The lower seat plate (7) is provided with a second concave spherical surface (15), which is a continuous variable curvature track formed by smooth transition and connection of at least two arc surfaces with different curvatures; the lower seat plate (7) is provided with a flexible limiting area (11). The middle seat plate (5) has a chamfer (10) on its edge. The chamfer (10) and the flexible limiting area (11) are limited by surface contact. The anti-fall beam support slides on the continuously variable curvature track through the middle seat plate (5).

2. The anti-fall beam support according to claim 1, characterized in that, The curvature of the second concave spherical surface (15) of the lower seat plate (7) increases or decreases continuously from the center outwards along its continuously variable curvature track.

3. The anti-fall beam support according to claim 1, characterized in that, When the middle seat plate (5) slides to the edge limit position of the continuous variable curvature track, the chamfer (10) forms a surface contact with the flexible limiting area (11).

4. The anti-fall beam support according to claim 1, characterized in that, The middle seat plate (5) has a double convex spherical structure, with its upper surface being a first convex spherical surface (13) and its lower surface being a second convex spherical surface (14).

5. The anti-fall beam support according to claim 1, characterized in that, The anti-fall beam support also includes a lower spherical stainless steel sliding plate (6) fixed on the second concave spherical surface (15) of the lower seat plate (7), and a lower spherical non-metallic sliding plate (9) fixed on the second convex spherical surface (14) of the middle seat plate (5); the lower spherical non-metallic sliding plate (9) and the lower spherical stainless steel sliding plate (6) constitute a second friction pair.

6. The anti-fall beam support according to claim 5, characterized in that, The lower spherical non-metallic sliding plate (9) is integrally embedded in the groove opened in the second convex spherical surface (14) of the middle seat plate (5), and smoothly transitions with the second convex spherical surface (14) of the middle seat plate (5), and the roughness Ra at the transition point is ≤1.0μm.

7. The anti-fall beam support according to claim 1, characterized in that, The anti-fall beam support also includes an upper seat plate (1), and the lower surface of the upper seat plate (1) is provided with a first concave spherical surface (12), which has a fixed curvature.

8. The anti-fall beam support according to claim 1, characterized in that, The anti-fall beam support also includes an upper spherical stainless steel sliding plate (2) fixed to the first concave spherical surface (12) of the upper seat plate (1), and an upper spherical non-metallic sliding plate (3) fixed to the first convex spherical surface (13) of the middle seat plate (5); the upper spherical non-metallic sliding plate (3) and the upper spherical stainless steel sliding plate (2) constitute a first friction pair.

9. The anti-fall beam support according to claim 1, characterized in that, Sealing rings are provided between the upper seat plate (1) and the middle seat plate (5) of the anti-fall beam support, and between the lower seat plate (7) and the middle seat plate (5).

10. The anti-fall beam support according to claim 1, characterized in that, The curvature of the lower spherical non-metallic slide plate (9) is the same as that of the lower spherical stainless steel slide plate (6) at the initial position of the continuous variable curvature track; the curvature of the upper spherical non-metallic slide plate (3) is the same as that of the upper spherical stainless steel slide plate (2).

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