Double-yield-point self-resetting buckling restrained brace with adjustable initial rigidity and easy-to-replace negative Poisson's ratio inner core

Abstract

The invention provides a double-yield-point self-resetting buckling restrained brace with an adjustable initial rigidity and an easy-to-replace negative poisson ratio inner core. The double-yield-point self-resetting buckling restrained brace mainly comprises an outer pipe; the end plate connecting plate is arranged outside the first end of the outer pipe; the first-order core energy consumption units are arranged on at least two opposite surfaces of the outer pipe, the first ends of the first-order core energy consumption units are fixedly connected with the end plate connecting plate, and the second ends of the first-order core energy consumption units are fixedly connected with the outer pipe; the rigidity-adjustable self-resetting unit is arranged at one end in the outer pipe, and the first end of the rigidity-adjustable self-resetting unit extends out of the first end of the outer pipe and is welded and fixed with the end plate connecting plate; and the second-order core energy consumption unit is arranged at the other end in the outer pipe, the first end of the second-order core energy consumption unit is fixedly connected with the second end of the rigidity-adjustable self-resetting unit, and the second end of the second-order core energy consumption unit is slidably connected with the second end of the outer pipe. The double-yield-point self-resetting buckling restrained brace combines the advantages of a self-resetting function and controllable initial rigidity, has efficient energy dissipation performance and automatic resetting capacity, is flexibly adapted according to different earthquake fortification requirements, and can quickly recover the structure function after an earthquake.

Description

Technical Field

[0001] The present invention relates to the technical field of building structures, in particular to the technical field of structural engineering energy dissipation and vibration reduction, and specifically to a double-yield point self-resetting buckling restraint brace with an adjustable initial stiffness and an easily replaceable negative Poisson's ratio core. Background Art

[0002] Earthquakes are among the most destructive natural disasters. Their sudden onset and massive energy release often inflict devastating impacts on building structures. In previous strong earthquakes, traditional supporting structures often lose their load-bearing capacity due to severe damage or excessive residual deformation. This not only directly threatens the overall safety of buildings, resulting in the awkward situation of "standing but not falling," but also severely hinders post-disaster emergency rescue and reconstruction efforts. Of particular concern is that irreversible deformation of supporting structures often forces the complete demolition of buildings, resulting in enormous economic losses and waste of social resources.

[0003] Traditional building structures typically adopt a "three-strength" seismic design concept, which aims to resist earthquakes by increasing structural strength, stiffness, and ductility. While this design approach can ensure that structures do not sustain significant damage or collapse during earthquakes, it has significant limitations in practice. First, in high-intensity earthquake zones, meeting seismic requirements often requires significantly increasing component cross-sectional dimensions, which not only wastes building materials but also significantly reduces usable building space. Second, this passive seismic approach makes it difficult to precisely control the path of structural damage, leading to excessive concentration of damage in critical areas. Third, after an earthquake, structures often experience irreversible residual deformations, which are difficult and costly to repair.

[0004] As a new generation of earthquake-resistant technology, the existing self-resetting energy-absorbing support combines the bearing capacity of traditional supports with the adaptive characteristics of smart materials. Its core advantages can be systematically summarized as follows: First, it has a two-stage protection mechanism. In the elastic stage, the initial stiffness is used to effectively control the deformation of the structure, and in the nonlinear stage, the seismic energy is dissipated through friction or metal dampers. Second, it has the ability to self-reset, reducing residual deformation after the earthquake. Third, it reduces the difficulty of maintenance and can quickly restore the structural function after an earthquake. Although it can effectively improve the energy dissipation and reset capacity of the structure, it still has defects: excessive initial stiffness will cause the first natural vibration period of the frame support system to be too small, and a too small first natural vibration period will cause the stiffness of the frame support system to be too large, which will affect the dynamic response characteristics of the structure. At the same time, the post-earthquake damage to the internal structure of the support is dispersed and cannot be effectively concentrated on the replaceable components.

[0005] Therefore, there is an urgent need to solve the problems of excessive initial stiffness and damage dispersion in the existing self-righting energy-absorbing support structure system. Summary of the Invention

[0006] In light of the shortcomings of existing technologies, the present invention provides a dual-yield-point, self-resetting buckling-restrained brace with an easily replaceable negative Poisson's ratio core and adjustable initial stiffness. This design aims to address the problems of excessive initial stiffness and damage dispersion that plague existing self-resetting brace structures. This brace combines the advantages of self-resetting with controllable initial stiffness, offering efficient energy dissipation and automatic reset capabilities. It can be flexibly adapted to various seismic fortification requirements, enabling rapid restoration of structural functionality after an earthquake. Furthermore, the brace's staged yielding design effectively improves the structure's seismic performance and economic benefits.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] The present invention first provides a double-yield point self-resetting buckling restraint support with an adjustable initial stiffness and an easily replaceable negative Poisson's ratio core, which mainly includes:

[0009] External control;

[0010] an end plate connecting plate, disposed outside the first end of the outer tube and used for connecting to the main building structure;

[0011] A first-order core energy consuming unit is provided on at least two opposite surfaces outside the outer tube, and a first end of the first-order core energy consuming unit is connected and fixed to the end plate connecting plate, and a second end of the first-order core energy consuming unit is connected and fixed to the outer tube;

[0012] A self-resetting unit with adjustable stiffness is provided at one end of the outer tube, wherein a first end of the self-resetting unit with adjustable stiffness extends out of the first end of the outer tube and is welded and fixed to the end plate connecting plate;

[0013] The second-order core energy consuming unit is arranged at the other end of the outer tube, and the first end of the second-order core energy consuming unit is fixedly connected to the second end of the adjustable stiffness self-resetting unit, and the second end is slidably connected to the second end of the outer tube.

[0014] Preferably, the first-order core energy dissipation unit includes two negative Poisson's ratio steel plates, which are respectively installed on the top plate and the bottom plate of the outer tube, and the first end is bolted and fixed to the end plate connecting plate, and the second end is bolted and fixed to the top plate and the bottom plate of the outer tube.

[0015] Preferably, the stiffness-adjustable self-resetting unit includes an inner tube and a disc spring group, the first end of the inner tube extends out of the first end of the outer tube and is welded and fixed to the end plate connecting plate, and at least one group of the disc spring group is sleeved on the inner tube.

[0016] Preferably, the stiffness-adjustable self-resetting unit also includes two disc spring baffles and multiple pull rods. The two disc spring baffles are sleeved on the inner tube to constrain the disc spring group. The multiple pull rods are passed through the two disc spring baffles to tighten the two disc spring baffles to pre-tighten the disc spring group.

[0017] Preferably, the first end of one group of the multiple pull rods is connected and fixed to the first end of the outer tube, and the second end is connected and fixed to a corresponding disc spring baffle, and can slide in another disc spring baffle; the first end of another group of the multiple pull rods is connected and fixed to a corresponding disc spring baffle, and the second end is connected and fixed to the second-order core energy consumption unit, and can slide in another disc spring baffle.

[0018] Preferably, the plurality of pull rods are of the same length to ensure the balance of support tension and compression.

[0019] Preferably, the second-order core energy dissipation unit includes a negative Poisson's ratio steel plate, the first end of the negative Poisson's ratio steel plate is fixedly connected to the second end of the inner tube by bolts, and the second end is provided with an oblong hole and is slidably connected to the outer tube.

[0020] Preferably, the negative Poisson's ratio steel plate is provided with peanut holes arranged in a horizontal and vertical array to form a negative Poisson's ratio effect.

[0021] Preferably, the negative Poisson's ratio steel plate of the first-order core energy dissipation unit is fastened to the top plate and bottom plate of the outer tube by bolts passing through peanut holes.

[0022] Preferably, the second-order core energy consumption unit also includes two channel steels, the negative Poisson's ratio steel plate is vertically arranged between the top plate and the bottom plate of the outer tube, the two channel steels are back-to-back arranged on both sides of the negative Poisson's ratio steel plate, and the upper and lower flanges of the channel steel are provided with bolt holes, and the top plate and the bottom plate of the outer tube are correspondingly provided with bolt holes, and the two are fixed by bolt connection.

[0023] Preferably, a bolt hole is provided on the web at the second end of the channel steel, and the second-order core energy dissipation unit is slidably connected to the outer tube by passing a bolt through the bolt hole and the oblong hole at the second end of the negative Poisson's ratio steel plate.

[0024] Preferably, the first-order core energy consumption unit further includes two outer cover plates, which are covered on the negative Poisson's ratio steel plate and are connected and fixed to the top plate and bottom plate of the outer tube;

[0025] Preferably, the outer cover plate includes two rectangular steel plates, both longitudinal edges and the second end of the rectangular steel plates are provided with bolt holes, the top plate, bottom plate and second end of the outer tube are provided with corresponding bolt holes, and the two rectangular steel plates are respectively fixed to the top plate and bottom plate of the outer tube by bolts.

[0026] The beneficial effects of the present invention over the prior art are as follows: the double-yield point self-resetting buckling restraint support provided by the present invention is based on the design concepts of staged yielding, replaceable energy-absorbing elements, suppression of out-of-plane buckling, and controllable initial stiffness, which can achieve staged yielding under different earthquake levels, overcome the drawbacks of traditional support stress concentration, difficulty in repair, and period mismatch problems involved in self-resetting supports, the fixed stiffness easily conflicts with the natural vibration period of the building, structural resonance, and the problem that damage cannot be concentrated on replaceable components; the combination of the energy-absorbing device and the self-resetting device of the support effectively achieves energy dissipation, buckling prevention, self-resetting and controllable initial stiffness. The two-stage cores are connected by high-strength bolts, which are easy to disassemble after damage, avoiding the problem of difficulty in replacing the support after plastic deformation; in the initial stage, only the target preload is applied to the disc spring group, and the steel rod is not subjected to force, making the support processing and assembly more convenient; the setting of the outer cover plate and the channel steel respectively suppresses the out-of-plane buckling of the first-order core and the second-order core. It has strong adaptability to dimensional errors and defects and is easy to install. Specifically:

[0027] 1. The self-resetting energy dissipation device adopts a staged yielding design, achieving a gradient response in seismic performance through the collaborative working mechanism of the first-order and second-order cores and the disc spring system. Under the action of small earthquakes, the reset system works together with the first-order core, and the structure mainly exhibits elastic deformation, demonstrating excellent post-earthquake reset capability; when a moderate earthquake occurs, the first-order core enters the yielding stage, and the load is gradually transferred to the disc spring system, achieving energy dissipation through its nonlinear deformation; under large earthquake conditions, the first-order core, the second-order core and the reset system work together, and the self-resetting device can effectively control the residual deformation of the structure, significantly reducing the plastic damage of the main structure, while improving the post-earthquake functional recoverability of the system. The multi-level energy dissipation mechanism takes into account the reset performance in the elastic stage, the energy dissipation capacity in the yield stage, and the damage control in the limit stage, providing layered seismic protection for building structures.

[0028] 2. Strong self-reset capability: The disc spring group and steel rod in the reset system are rationally designed to ensure that the structure can be quickly restored to its original state after an earthquake, significantly reducing residual deformation after an earthquake.

[0029] 3. Modular design offers enhanced convenience: The device utilizes a modular design concept, with components connected via high-strength bolts, significantly enhancing ease of maintenance. When a specific energy-consuming component (such as the primary or secondary core) is damaged, only partial replacement of the damaged unit is required to restore the overall functionality of the device, avoiding the high cost of replacing the entire structure with a traditional one. This targeted replaceable mechanism not only significantly reduces maintenance difficulty and downtime, but also achieves significant economic benefits by minimizing the scope of repairs. This shortens maintenance cycles and demonstrates outstanding economic advantages throughout the entire lifecycle.

[0030] 4. Multiple Coordination Mechanisms: The support system utilizes a multi-mechanism collaborative design, leveraging the energy dissipation characteristics of the first- and second-order cores and the self-resetting capability of the disc spring system to achieve hierarchical control of seismic energy. Across the full operating range, from minor to major earthquakes, each component exhibits a timed activation characteristic based on the magnitude of the input energy: the first-order core provides initial stiffness and dissipates energy first, the second-order core participates in plastic dissipation under moderate to high intensities, and the disc spring system continuously provides reset functionality through nonlinear restoring forces. This multi-mechanism coupling not only significantly improves the adaptability of support components under varying earthquake intensities, but also optimizes the overall structural response through internal force redistribution, balancing seismic safety and ductility requirements.

[0031] 5. Improve the certainty of the support seismic response: Through the reasonable arrangement of steel rods, the influence of excessive initial stiffness on the uncertainty of the structural seismic response is resolved, thereby accurately predicting the fundamental period of the structure; at the same time, it is easy to process and install, improving the adaptability of the support to the actual engineering installation process.

[0032] 6. The present invention connects the peripheral restraint components on both sides by passing the peripheral connecting bolts through the negative Poisson's ratio first-order core. The bolt-through-hole connection design can achieve miniaturization and lightweight of the peripheral restraint components, effectively solving the problems of large cross-section and heavy components of traditional integral restraint type and fully assembled binding restraint type buckling restraint support peripheral components. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0034] The structures, proportions, sizes, etc. illustrated in this specification are intended solely to complement the contents disclosed herein and to facilitate understanding and reading by persons skilled in the art. They are not intended to limit the conditions under which the present invention may be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in sizes, provided they do not affect the efficacy and objectives of the present invention, shall remain within the scope of the technical contents disclosed herein.

[0035] Figure 1 A three-dimensional diagram of a double-yield point self-resetting buckling restrained brace with an adjustable initial stiffness and an easily replaceable negative Poisson's ratio core is shown as an example;

[0036] Figure 2 An example of a split diagram of a double-yield-point self-resetting buckling restrained brace with an adjustable initial stiffness and an easily replaceable negative Poisson's ratio core is shown;

[0037] Figure 3 An exemplary top view of a double-yield-point self-resetting buckling restraint brace with an adjustable initial stiffness and an easily replaceable negative Poisson's ratio core is shown;

[0038] Figure 4 A front view of a double-yield-point self-resetting buckling restrained brace with an adjustable initial stiffness and an easily replaceable negative Poisson's ratio core is shown as an example;

[0039] Figure 5 An example diagram showing the internal structure of a double-yield-point self-resetting buckling restraint brace with an adjustable initial stiffness and an easily replaceable negative Poisson's ratio core;

[0040] Figure 6 An exemplary diagram of the connection structure of a double-yield-point self-resetting buckling restrained brace with an adjustable initial stiffness and an easily replaceable negative Poisson's ratio core is shown;

[0041] Figure 7 An example of a first-order core arrangement diagram of a double-yield point self-resetting buckling restrained support with an easily replaceable negative Poisson's ratio core and adjustable initial stiffness is shown;

[0042] Figure 8 The reset system diagram of a double-yield point self-resetting buckling restrained support with an adjustable initial stiffness and an easily replaceable negative Poisson's ratio core is shown as an example.

[0043] Markings in the figure:

[0044] Second-order core energy dissipation unit 1, inner tube 2, first-order core energy dissipation unit 3, outer tube 4, disc spring group 5, disc spring baffle 6, channel steel 7, end plate connecting plate 8, pull rod 9, outer cover plate 10, ribbed steel plate 11, high-strength bolt group one 12, high-strength bolt group two 13, high-strength bolt group three 14, high-strength bolt group four 15, oblong hole 16, limit stop 17.

[0045] In the various drawings, the same or corresponding reference numerals denote the same or corresponding parts. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with the embodiments and drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0047] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0048] It should be understood that the terms "comprises / comprising," "consisting of," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product, apparatus, process, or method that includes a list of elements includes not only those elements but also, if necessary, other elements not explicitly listed, or elements inherent to such product, apparatus, process, or method. In the absence of further limitations, elements defined by the phrases "comprises / comprising," "consisting of," do not preclude the presence of additional identical elements in the product, apparatus, process, or method that includes the elements.

[0049] It should also be understood that terms such as "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device, component or structure referred to must have a specific direction, be constructed or operate in a specific direction, and should not be understood as limiting the present invention.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0051] The specific implementation and preferred solution of the double-yield-point self-resetting buckling restrained support proposed by the present invention are described in detail below.

[0052] The present invention studies a double yield point self-resetting buckling restraint support, such as Figure 1-8As shown, it mainly includes: an outer tube 4, an end plate connecting plate 8, a first-order core energy consuming unit 3, a stiffness-adjustable self-resetting unit, and a second-order core energy consuming unit 1, wherein the outer tube 4 serves as a supporting frame body, the end plate connecting plate 8 is used to connect to the main structure of the building, the first end of the first-order core energy consuming unit 3 is connected and fixed to the end plate connecting plate 8, and the second end is connected and fixed to the outer tube 4, the first end of the stiffness-adjustable self-resetting unit extends to the outside of the first end of the outer tube 4 and is welded to the end plate connecting plate 8, the first end of the second-order core energy consuming unit 1 is connected and fixed to the second end of the stiffness-adjustable self-resetting unit, and the second end is connected to The second end of the outer tube 4 is slidably connected, thus forming a reset system and a two-stage energy dissipation system. The first-order core energy dissipation unit is connected to the end plate connecting plate 8, while the adjustable stiffness self-reset unit is also connected to the end plate connecting plate 8. The first end of the second-order core energy dissipation unit is fixedly connected to the second end of the adjustable stiffness self-reset unit. That is, through the mediation of the end plate connecting plate 8, the second-order core energy dissipation unit and the first-order core energy dissipation unit are connected in series. In the initial stage (small earthquake), the support mainly exhibits elastic deformation, and the energy dissipation components (first-order core energy dissipation unit) and the adjustable stiffness self-reset unit are stressed, and the structural reset capability is outstanding. During moderate earthquakes, the energy dissipation components (first-order core energy dissipation unit) begin to yield, providing energy dissipation capacity, and the adjustable stiffness self-reset unit gradually takes effect. During large earthquakes, the energy dissipation components (first-order core energy dissipation unit and second-order core energy dissipation unit) fully dissipate energy, and both the first-order core energy dissipation unit and the second-order core energy dissipation unit yield. The adjustable stiffness self-reset unit can prevent excessive residual deformation and reduce structural damage.

[0053] See also Figure 2 In a specific embodiment, a preferred first-order core energy dissipation unit structure is provided. The first-order core energy dissipation unit 3 includes two negative Poisson's ratio steel plates, which are respectively installed on the top plate and the bottom plate of the outer tube 4. The first end of the negative Poisson's ratio steel plate is provided with a bolt hole and is connected and fixed to the end plate connecting plate 8 by a high-strength bolt group 15. The second end of the negative Poisson's ratio steel plate is provided with a bolt hole and is connected and fixed to the top plate and the bottom plate of the outer tube 4 by a high-strength bolt group 12.

[0054] Specifically, the end plate connecting plate 8 is arranged vertically, and the negative Poisson's ratio steel plate is arranged horizontally. A vertical connecting plate is welded on the inner side of the end plate connecting plate 8, and a vertical connecting plate is welded to the first end of the negative Poisson's ratio steel plate. Bolt holes are correspondingly opened on the vertical connecting plates of the two, and they are connected and fixed by a high-strength bolt group 15.

[0055] The energy dissipation mode of the first-order inner core energy dissipation unit 3 is to form peanut-shaped holes arranged in an array on the negative Poisson's ratio steel plate, the high-strength bolts (high-strength bolt group 12) pass through the center of each longitudinal peanut-shaped hole, that is, one horizontal and one vertical are alternated, and the array is arranged in multiple rows and multiple columns, one horizontal peanut-shaped hole alternates with one vertical peanut-shaped hole in the same row, and one vertical peanut-shaped hole alternates with one horizontal peanut-shaped hole in the same column. Through reasonable design of the opening rate, lightweight design is performed to achieve the effect of reducing the self weight. The high-strength bolts pass through the center of the vertically arranged peanut-shaped holes to improve the rational displacement of the first-order inner core energy dissipation unit, and at the same time realize the negative Poisson's ratio effect of the component, so that the inner core component exhibits the characteristics of horizontal shrinkage when stressed, thereby avoiding the buckling instability problem caused by horizontal expansion in the traditional structure, and realizing the effect of free buckling. The negative Poisson's ratio characteristic makes the inner core component have stronger ductility, improves the ductility and durability of the component, and can maintain stable performance under multiple seismic loads. In addition, this characteristic optimizes the energy dissipation mechanism and improves the energy absorption and seismic capacity of the structure under extreme strong earthquakes.

[0056] The opening rate of the peanut-shaped hole is determined according to the design requirements. If the opening rate is too small, the negative Poisson's ratio effect cannot be achieved, and if the opening rate is too large, the structural strength cannot be guaranteed. Research shows that an opening rate of 40-50% is appropriate, that is, a solid rate of 50-60% is a reasonable range.

[0057] Of course, in addition to peanut-shaped holes, elliptical holes, star-shaped holes and other plate members with negative Poisson's ratio characteristics can also be used.

[0058] More specifically, in addition to forming peanut-shaped holes on the negative Poisson's ratio steel plate, the high-strength bolts (high-strength bolt group 12) also pass through the vertically arranged peanut-shaped holes to form perforated ties, which constrain the adverse deformation and displacement of the negative Poisson's ratio steel plate, that is, the steel plate is maximally displaced vertically to form a negative Poisson's ratio effect. The perforated tie design of the peripheral connecting bolts can realize the miniaturization and lightweight of the peripheral constraint component, effectively solving the problems of large cross section and heavy component of the traditional overall constraint type and fully assembled bundled constraint type buckling restrained brace peripheral component.

[0059] Preferably, a gap of 10-25 mm is reserved between the two negative Poisson's ratio steel plates and the top plate and the bottom plate of the outer tube 4 to avoid local compressive stress when the first-order inner core energy dissipation unit 3 and the outer tube 4 move relatively, which can damage the main structure.

[0060] Continuing to refer to Figure 2 , Figure 4-6The self-resetting unit with adjustable stiffness includes an inner tube 2 and a disc spring group 5. The inner tube 2 is a round tube inserted into the outer tube 4. The first end of the inner tube 2 (i.e., the left end in the figure) extends out of the first end of the outer tube 4 and is welded and fixed to the end plate connecting plate 8. At least one disc spring group 5 is sleeved on the inner tube 2. With the first end of the inner tube 2 being welded and fixed to the end plate connecting plate 8, the negative Poisson's ratio steel plate is also connected and fixed to the end plate connecting plate 8. When force begins to act, the two negative Poisson's ratio steel plates begin to consume energy through the connection of the end plate connecting plate 8, and the negative Poisson's ratio steel plates move synchronously with the inner tube 2. However, since the second end of the second-order core energy dissipation unit 1 is slidable, the second-order core energy dissipation unit 1 does not consume energy at this time. This is the first-order energy dissipation stage.

[0061] In one specific embodiment, the adjustable stiffness self-reset unit further includes two disc spring baffles 6, which are sleeved onto the inner tube 2. The disc spring assembly 5 is positioned between the two disc spring baffles 6 to constrain the disc spring assembly 5. Specifically, a limit stop 17 can be sleeved onto the inner tube 2. The nested limit stop 17 can flexibly move on the inner tube 2 when preload is applied to the disc spring assembly 5. When the disc spring assembly 5 is adjusted to the desired preload value, the limit stop 17 is fixed and thereafter does not move on the inner tube 2, i.e., the limit stop 17 remains in close contact with the disc spring baffles 6. The disc spring baffles 6 can be shaped appropriately, such as square, rectangular, circular, or oblong.

[0062] In a specific embodiment, the stiffness-adjustable self-resetting unit also includes eight pull rods 9, and eight through holes are correspondingly opened on the two disc spring baffles 6. The eight pull rods 9 are passed through the two disc spring baffles 6 and are used to pre-tighten the disc spring group 5 by tightening the two disc spring baffles 6 when deformed by force.

[0063] When the force begins to act, the inner tube 2 moves synchronously with the negative Poisson's ratio steel plate through the end plate connecting plate 8, driving the pull rod 9 to move, generating tension. During the support force process, when the tension of the pull rod 9 is less than the initial preload of the disc spring, the restoring force of the disc spring group 5 remains unchanged, i.e., the initial preload. As the force gradually increases, the tension of the pull rod 9 gradually reaches or even exceeds the initial preload of the disc spring. At this time, due to the arrangement of the pull rod 9, the disc spring group 5 is further compressed, and the restoring force of the disc spring group 5 gradually increases. As the displacement continues to increase, the second-order core energy dissipation unit 1 begins to dissipate energy, which is the second-order energy dissipation stage. Analysis shows that through the arrangement of the steel rods, the support can meet the requirements of disc spring size and restoring force.

[0064] More specifically, the eight pull rods 9 are divided into two groups, four in each group, wherein the first end of one group is connected and fixed to the first end of the outer tube 4, and the second end is connected and fixed to the corresponding disc spring baffle 6 ( Figure 2 The disc spring baffle 6 on the right side of the middle), the first end of the outer tube 4 starts to have four through holes, and the corresponding disc spring baffle 6 starts to have four through holes, that is Figure 2The four through holes in the middle of the four sides of the middle disc spring baffle 6, the four pull rods 9 can be connected to the other disc spring baffle 6 ( Figure 2 Similarly, the first ends of the other four pull rods 9 are connected and fixed to the corresponding disc spring baffle 6 ( Figure 2 The second end of the disc spring baffle 6 on the left side is connected and fixed to the second-order core energy dissipation unit, and can be connected to the other disc spring baffle ( Figure 2 The disc spring baffle 6) on the right side slides freely.

[0065] The initial disc spring preload can be adjusted by changing the position of the limit stop 17. When the support is pulled or compressed, as the displacement increases, when the tension on a set of steel rods is greater than the disc spring preload, the disc spring begins to be compressed and the restoring force increases. Specifically, if the support is compressed, it drives the inner tube 2 and the disc spring group 5 thereon to move to the right, and the disc spring baffle 6 on the left side slides freely to the right on one set of pull rods 9. The disc spring baffle 6 on the right side cannot move due to the restriction of the set of pull rods 9, squeezing the disc spring group 5, compressing the disc spring group 5, and gradually increasing the restoring force of the disc spring group 5. Similarly, if the support is pulled, it drives the inner tube 2 and the disc spring group 5 thereon to move to the left, and the disc spring baffle 6 on the right side slides freely to the left on the other set of pull rods 9. The disc spring baffle 6 on the left side cannot move due to the restriction of the set of pull rods 9, squeezing the disc spring group 5, compressing the disc spring group 5, and gradually increasing the restoring force of the disc spring group 5.

[0066] The pull rods 9 can be made of steel rods, and multiple pull rods 9 have the same length to ensure the balance of support tension and compression.

[0067] Continue to see Figure 2 In one embodiment, a preferred second-order core energy dissipation unit structure is provided. The second-order core energy dissipation unit 1 also utilizes a negative Poisson's ratio steel plate, which is suitable for both processing, manufacturing, and assembly. Similar to the first-order core energy dissipation unit 3, the negative Poisson's ratio steel plate is provided with peanut holes arranged in a horizontal and vertical array. The specific arrangement and function of the peanut holes are similar to those of the first-order core. It should be noted that the hole pattern must first enable the first-order core energy dissipation unit to exhibit a negative Poisson's ratio effect. The hole pattern of the second-order core energy dissipation unit and the first-order core energy dissipation unit can be the same or different, as long as the negative Poisson's ratio effect can be achieved within a reasonable hole pattern range.

[0068] The negative Poisson's ratio steel plate has a bolt hole at its first end (left end in the figure) and is connected to the second end of the disc spring group 5 through a high-strength bolt group 13. The second end of the negative Poisson's ratio steel plate has an oblong hole 16 that is slidably connected to the outer tube 4. Figure 5 、 Figure 6 By means of the sliding connection mode of the oblong hole, when the negative Poisson's ratio steel plate and the inner tube 2 move synchronously, the negative Poisson's ratio steel plate does not temporarily participate in energy consumption.

[0069] For example Figure 2 、 Figure 4 、 Figure 5 As shown, the second-order core energy dissipation unit 1 also includes two channel steels 7. A negative Poisson's ratio steel plate is vertically arranged between the top and bottom plates of the outer tube 4. The two channel steels 7 are arranged with their webs back-to-back on either side of the negative Poisson's ratio steel plate, thus clamping the negative Poisson's ratio steel plate in the middle. Bolt holes are provided on the upper and lower flanges of the channel steels 7, and corresponding bolt holes are provided on the top and bottom plates of the outer tube 4. The two are connected and fixed by a group of high-strength bolts 12. The channel steels 7 are connected and fixed to the negative Poisson's ratio steel plate and the outer tube 4 simultaneously. The channel steels 7 not only firmly fix the negative Poisson's ratio steel plate, but also exert a restraining effect on the negative Poisson's ratio steel plate, ensuring that the negative Poisson's ratio steel plate exhibits lateral contraction characteristics when subjected to stress, thereby avoiding buckling instability caused by lateral expansion. At the same time, when experiencing extreme earthquakes, the negative Poisson's ratio steel plate may fracture due to large deformation. At this time, the constraint of the channel steels 7 serves as the last line of defense, continuing to bear the load, thereby achieving the fracture-free characteristic.

[0070] Furthermore, in order to improve the overall rigidity of the channel steel 7 to ensure the fixing effect and the restraining effect, the channel steel 7 adopts a ribbed channel steel, and one or more stiffening ribs are welded between the upper and lower flanges and the web of the channel steel, and the stiffening ribs separate the channel steel into multiple areas.

[0071] Continue to see Figure 4 、 Figure 5 In a specific embodiment, circular bolt holes are opened on the web of the second end of the channel steel 7. The number and position of the bolt holes correspond to the oblong hole 16 at the second end of the negative Poisson's ratio steel plate. The negative Poisson's ratio steel plate is slidably connected to the outer tube 4 by a high-strength bolt group 14 passing through the bolt holes and the oblong hole 16 at the second end of the negative Poisson's ratio steel plate.

[0072] In order to facilitate the connection between the disc spring group 5 and the negative Poisson's ratio steel plate, a ribbed steel plate 11 is welded to the second end of the disc spring group 5 (i.e., the right end in the figure). The ribbed steel plate 11 is provided with bolt holes. The first end of the negative Poisson's ratio steel plate is provided with corresponding bolt holes. The two are connected and fixed by a high-strength bolt group 13. Figure 2 、 Figure 5 As shown, two ribbed steel plates 11 are vertically welded and spaced apart, clamping the first end of the negative Poisson's ratio steel plate in the middle.

[0073] See also Figure 1 、 Figure 2 The first-order core energy consumption unit is also provided with an outer cover plate 10, which is covered on the negative Poisson's ratio steel plate and is connected and fixed to the top plate and bottom plate of the outer tube 4.

[0074] Specifically, the outer cover plate 10 includes two rectangular steel plates, each of which has bolt holes on its edge and second end. The top plate, bottom plate and second end of the outer tube 4 have corresponding bolt holes. The two rectangular steel plates are respectively connected and fixed to the top plate and bottom plate of the outer tube 4 by a high-strength bolt group 12.

[0075] The outer cover plate 10 provides an external restraint effect on the negative Poisson's ratio steel plate inside the outer cover plate 10 , which is similar to the restraint effect of the channel steel 7 on the negative Poisson's ratio steel plate.

[0076] At this time, the high-strength bolt group 12 passes through the bolt holes on the outer cover plate 10, the peanut holes on the negative Poisson's ratio steel plate of the first-order core energy dissipation unit 3, and the bolt holes on the top plate and bottom plate of the outer tube 4 to form an effective perforation tie.

[0077] In summary, the present invention provides a double-yield point self-resetting buckling restraint support with an easily replaceable negative Poisson's ratio core and adjustable initial stiffness, which is composed of a reset system and a two-stage energy dissipation system. The reset system is mainly composed of an inner tube 2, an outer tube 4, a group of disc springs 5 ​​and eight steel rods. When an external force acts, the inner tube 2 and the outer tube 4 undergo relative displacement, driving the steel rod to move and generating tension. At this time, the restoring force of the disc spring group is equal to the pre-stress of the disc spring group; when the external force gradually increases, the tension of the steel rod gradually increases. When the tension of the steel rod exceeds the pre-stress of the disc spring group, the disc spring baffle slides, the restoring force of the disc spring group gradually increases, and the self-resetting ability is enhanced. The two-stage energy dissipation system mainly consumes energy by the joint action of a first-order core energy dissipation unit, a second-order core energy dissipation unit and a number of high-strength bolt groups, thereby realizing double-yield point self-resetting energy dissipation.

[0078] During the initial stage (small earthquakes), the support primarily exhibits elastic deformation, with the first-order core energy dissipation unit and the self-resetting unit with adjustable stiffness bearing the load, demonstrating the structure's outstanding reset capability. At this point, the second-order core energy dissipation unit, due to its sliding connection to the outer tube, has an allowable sliding stroke, during which it temporarily does not dissipate energy.

[0079] During moderate earthquakes, the energy-absorbing components (first-order core energy-absorbing units) begin to yield, providing energy-absorbing capacity, while the self-resetting units with adjustable stiffness continue to function. At this point, the energy-absorbing stage of the second-order core energy-absorbing units may not yet be reached.

[0080] During a major earthquake, the energy-absorbing components fully consume energy, and both the first-order core energy-absorbing unit and the second-order core energy-absorbing unit yield. The self-resetting unit with adjustable stiffness can prevent excessive residual deformation, reduce structural damage, and quickly restore structural function after the earthquake.

[0081] Furthermore, the negative Poisson's ratio effect of the apertures created by the first- and second-order core energy dissipation units allows for the absorption of additional energy under impact loads through their unique lateral expansion, effectively mitigating damage to the dual-yield point self-centering buckling restrained brace. Under tension or compression, the lateral expansion of the negative Poisson's ratio material within this support's dual-stage energy dissipation system effectively disperses loads and reduces localized stress concentrations.

[0082] Although several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of the present invention. Certain features described in the context of separate embodiments may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented in multiple implementations individually or in any suitable sub-combination.

Claims

1. A double-yield-point self-resetting buckling restraint brace with an adjustable initial stiffness and an easily replaceable negative Poisson's ratio core, characterized in that: Mainly include: External control; an end plate connecting plate, disposed outside the first end of the outer tube and used for connecting to the main building structure; A first-order core energy consuming unit is provided on at least two opposite surfaces outside the outer tube, and a first end of the first-order core energy consuming unit is connected and fixed to the end plate connecting plate, and a second end of the first-order core energy consuming unit is connected and fixed to the outer tube; A self-resetting unit with adjustable stiffness is provided at one end of the outer tube, wherein a first end of the self-resetting unit with adjustable stiffness extends out of the first end of the outer tube and is welded and fixed to the end plate connecting plate; The second-order core energy consuming unit is arranged at the other end of the outer tube, and the first end of the second-order core energy consuming unit is fixedly connected to the second end of the adjustable stiffness self-resetting unit, and the second end is slidably connected to the second end of the outer tube.

2. The double-yield point self-resetting buckling restrained brace according to claim 1, characterized in that: The first-order core energy dissipation unit includes two negative Poisson's ratio steel plates, which are respectively installed on the top plate and the bottom plate of the outer tube, and the first ends are bolted and fixed to the end plate connecting plate, and the second ends are bolted and fixed to the top plate and the bottom plate of the outer tube.

3. The double-yield point self-resetting buckling restrained brace according to claim 1, characterized in that: The stiffness-adjustable self-resetting unit includes an inner tube and a disc spring group. The first end of the inner tube extends out of the first end of the outer tube and is welded and fixed to the end plate connecting plate. At least one group of the disc spring group is sleeved on the inner tube.

4. The double-yield point self-resetting buckling restrained brace according to claim 3, characterized in that: The stiffness-adjustable self-resetting unit also includes two disc spring baffles and multiple pull rods. The two disc spring baffles are sleeved on the inner tube to constrain the disc spring group. The multiple pull rods are passed through the two disc spring baffles and are used to tighten the two disc spring baffles to pre-tighten the disc spring group.

5. The double-yield point self-resetting buckling restrained brace according to claim 4, characterized in that: One group of the plurality of pull rods has a first end connected and fixed to the first end of the outer tube, and a second end connected and fixed to a corresponding disc spring baffle, and can slide in another disc spring baffle; another group of the plurality of pull rods has a first end connected and fixed to a corresponding disc spring baffle, and a second end connected and fixed to the second-order core energy consumption unit, and can slide in another disc spring baffle. Preferably, the plurality of pull rods are of the same length to ensure the balance of support tension and compression.

6. The double-yield-point self-resetting buckling restrained brace according to claim 3, characterized in that: The second-order core energy dissipation unit includes a negative Poisson's ratio steel plate, a first end of which is fixedly connected to the second end of the inner tube by bolts, and a second end is provided with an oblong hole which is slidably connected to the outer tube.

7. The double-yield-point self-resetting buckling-restrained brace according to claim 2 or 6, characterized in that: The negative Poisson's ratio steel plate is provided with peanut holes arranged in a horizontal and vertical array to form a negative Poisson's ratio effect; Preferably, the negative Poisson's ratio steel plate of the first-order core energy dissipation unit is fastened to the top plate and bottom plate of the outer tube by bolts passing through peanut holes.

8. The double-yield-point self-resetting buckling-restrained brace according to claim 6, characterized in that: The second-order core energy dissipation unit also includes two channel steels. The negative Poisson's ratio steel plate is vertically arranged between the top plate and the bottom plate of the outer tube. The two channel steels are arranged back to back on both sides of the negative Poisson's ratio steel plate, and the upper and lower flanges of the channel steel are provided with bolt holes. The top plate and the bottom plate of the outer tube are correspondingly provided with bolt holes, and the two are fixed by bolt connection.

9. The double-yield-point self-resetting buckling-restrained brace according to claim 8, characterized in that: A bolt hole is provided on the web at the second end of the channel steel, and the second-order core energy dissipation unit is slidably connected to the outer tube by passing a bolt through the bolt hole and the oblong hole at the second end of the negative Poisson's ratio steel plate.

10. The double-yield-point self-resetting buckling-restrained brace according to claim 2, characterized in that: The first-order core energy consumption unit further includes two outer cover plates, which are covered on the negative Poisson's ratio steel plate and are connected and fixed to the top plate and bottom plate of the outer tube; Preferably, the outer cover plate includes two rectangular steel plates, both longitudinal edges and the second end of the rectangular steel plates are provided with bolt holes, the top plate, bottom plate and second end of the outer tube are provided with corresponding bolt holes, and the two rectangular steel plates are respectively fixed to the top plate and bottom plate of the outer tube by bolts.

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