Rectangular steel tube self-centering graded energy dissipation buckling-restrained brace

Abstract

This invention proposes a self-resetting graded energy-dissipating buckling restraint brace for rectangular steel tubes, mainly comprising: a rectangular steel tube self-resetting device, consisting of two rectangular steel tubes connected by a self-resetting connection device; a first-order energy-dissipating inner core, disposed on the upper and lower sides of the two rectangular steel tubes at the connection; a second-order energy-dissipating inner core, disposed on the left and right sides of the two rectangular steel tubes at the connection; and an outer rectangular buckling-restrained sleeve, fitted onto the two rectangular steel tubes at the connection, with its upper and lower sides connected to the first-order energy-dissipating inner core and the upper and lower sides of the two rectangular steel tubes, and its left and right sides connected to the second-order energy-dissipating inner core and the left and right sides of the two rectangular steel tubes; and the first-order energy-dissipating inner core and the rectangular steel tube self-resetting device are capable of axial sliding with a first displacement relative to the second-order energy-dissipating inner core and the outer rectangular buckling-restrained sleeve. This invention effectively improves the mechanical properties of the brace through the first-order and second-order negative Poisson's ratio sequential energy-dissipating inner cores and the disc spring reset device.

Description

Technical Field

[0001] This invention relates to the field of building structure technology, and in particular to the field of energy dissipation and vibration reduction technology in structural engineering, specifically to a rectangular steel tube self-resetting graded energy dissipation buckling restraint brace. Background Technology

[0002] Steel frame structures, as an important lateral resistance system, are widely used in earthquake-prone areas. Beam-column connections play a crucial role in transferring slab loads to vertical load-bearing members. Frame structures designed according to traditional concepts dissipate seismic energy through plastic deformation in the core area, such as through plastic hinges in beam segments and buckling-restrained braced cores. This design method is widely accepted by designers due to its relatively clear force mechanism and simple construction. However, plastic deformation of the main structure often leads to irreversible structural damage, resulting in significant economic losses. To address this issue, structures designed based on the concept of centralized control of plastic damage have emerged.

[0003] Steel frame structures designed with concepts such as centralized control of plastic damage and replaceable energy-dissipating components can effectively control plastic damage at the energy-dissipating components, while the main structure remains elastic. After an earthquake, only the energy-dissipating components that have caused irreversible plastic damage need to be replaced to restore the structural function of the building. This reduces the difficulty of post-earthquake repair of traditional steel structures, thereby reducing economic losses caused by repair difficulties and loss of building function. However, current experience shows that although structures with embedded replaceable components can effectively control plastic damage, excessive residual deformation may still exist in the structure after an earthquake. The presence of residual deformation still poses a serious threat to the safety of the building.

[0004] Therefore, embedding components that integrate self-resetting and centralized control of plastic damage within steel frames has become an important means to improve the seismic performance of buildings and ensure their post-earthquake repairability. However, existing self-resetting technologies often struggle to balance high energy dissipation capacity and stable reset performance, especially under strong earthquakes where reset capacity may degrade or energy dissipation may occur.

[0005] In view of the above, the present invention is hereby proposed. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention provides a rectangular steel tube self-resetting graded energy dissipation buckling restraint brace, which is a self-resetting buckling restraint brace based on a negative Poisson ratio time-series energy dissipation core, aiming to improve the seismic performance of buildings and coordinate the inter-story deformation of buildings under seismic loading.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] This invention first provides a rectangular steel tube self-resetting graded energy-dissipating buckling restraint brace, mainly comprising:

[0009] A rectangular steel pipe self-resetting device is composed of two rectangular steel pipes connected by a self-resetting connecting device. When subjected to force, the rectangular steel pipe self-resetting device can generate axial displacement and provide a resetting force through the self-resetting connecting device.

[0010] The first-order energy-dissipating inner core is connected and fixed to the upper and lower sides of the two rectangular steel tubes at the docking joint.

[0011] The second-order energy-dissipating inner core is connected and fixed to the left and right sides of the two rectangular steel tubes at the docking joint.

[0012] The outer rectangular buckling-resisting sleeve is fitted onto the two rectangular steel pipes at the butt joint. Its upper and lower sides are connected and fixed to the upper and lower sides of the first-stage energy-dissipating inner core and the two rectangular steel pipes, and its left and right sides are connected and fixed to the second-stage energy-dissipating inner core and the left and right sides of the two rectangular steel pipes.

[0013] The first-order energy-dissipating inner core and the rectangular steel pipe self-resetting device can produce an axial sliding with a first displacement relative to the second-order energy-dissipating inner core and the outer rectangular anti-buckling sleeve.

[0014] Preferably, the self-resetting connection device includes two oppositely arranged disc spring baffles and a plurality of disc spring groups installed on the two disc spring baffles, and the two disc spring baffles are respectively welded and fixed to the ends of two rectangular steel pipes.

[0015] Preferably, each of the plurality of disc spring groups includes a disc spring unit one, two disc spring units two, and a disc spring anchor. The disc spring anchor is inserted through the two disc spring baffles. One disc spring unit is fitted onto the disc spring anchor between the two disc spring baffles, and the two disc spring units two are respectively fitted onto the disc spring anchors outside the two disc spring baffles.

[0016] Preferably, the first-order energy-dissipating inner core adopts two rectangular steel plates. The two rectangular steel plates are respectively set on the upper and lower sides of the two rectangular steel tubes at the butt joint, and a weakening zone is formed in the middle of the two rectangular steel plates. Circular holes are opened at both ends, and circular holes are opened on the upper and lower sides of the two rectangular steel tubes respectively. They are connected by a group of high-strength bolts.

[0017] Preferably, the second-order energy-consuming inner core adopts two shaped steel plates, which are respectively set on the left and right sides of the two rectangular steel pipes at the butt joint. The middle of the two shaped steel plates forms a weakening zone, and elongated holes are opened at both ends. Circular holes are opened on the left and right sides of the two rectangular steel pipes respectively, and they are connected by a group of high-strength bolts.

[0018] Preferably, the weakening region is provided with peanut-shaped holes arranged in an alternating horizontal and vertical array to create a negative Poisson's ratio effect.

[0019] Preferably, the outer rectangular buckling-resistant sleeve is a box-shaped sleeve fitted onto the two rectangular steel pipes at the butt joint. The box-shaped sleeve has elongated holes 2 on its upper and lower sides corresponding to the first and second round holes, and is connected by a group of high-strength bolts. At the same time, the box-shaped sleeve has elongated holes 3 on its left and right sides corresponding to the first and third round holes, and is connected by a group of high-strength bolts.

[0020] Preferably, the third elongated hole is longer than the first elongated hole, so that the rectangular steel pipe self-resetting device and the first-order energy-dissipating inner core and the second-order energy-dissipating inner core can slide axially with a second displacement relative to the outer rectangular anti-buckling sleeve.

[0021] Preferably, the second elongated hole is longer than the third elongated hole, and the first-order energy-dissipating inner core is longer than the second-order energy-dissipating inner core.

[0022] Preferably, the rectangular steel pipe self-resetting device is further provided with anti-bending fork ribs at the butt joint, and four sets of the anti-bending fork ribs are welded together from all four sides between the two disc spring baffles.

[0023] Preferably, each set of anti-buckling fork ribs is formed by two semi-trapezoidal structures interlocking with each other.

[0024] The present invention also provides an application of the buckling restraint support described herein in multi-story and high-rise prefabricated buildings.

[0025] The beneficial effects of this invention compared to the prior art are as follows: The rectangular steel tube self-resetting graded energy-dissipating buckling restraint brace provided by this invention effectively improves the mechanical properties of the brace through a first-order and second-order negative Poisson's ratio time-series energy-dissipating inner core and a disc spring reset device. Specifically, it can bring at least the following beneficial effects:

[0026] 1. This invention is designed based on the concept of centralized control of plastic damage and replaceable energy-consuming elements. All plastic damage can be centrally controlled on the energy-consuming elements, that is, all plastic damage is controlled on the first-order and second-order negative Poisson's ratio energy-consuming cores. After an earthquake, only the energy-consuming cores need to be replaced for continued use.

[0027] 2. This invention effectively improves the ductility of the energy-dissipating core by setting holes with negative Poisson ratio characteristics in the core, meaning the entire support can withstand greater deformation. The negative Poisson ratio structure has better adaptability to impact loads, meaning this type of support is more suitable for deployment in near-fault areas to cope with near-fault earthquakes with pulse effects that cause greater damage to buildings. The negative Poisson ratio core also produces multi-wave effects under compression, but based on finite element analysis, it requires less thickness of the outer components compared to dog-bone structures. In this invention, the thickness of the outer rectangular buckling-resistance sleeve and buckling-resistance fork ribs can be effectively controlled, which means that steel can be saved to a certain extent to reduce costs.

[0028] 3. Excellent self-resetting capability. This invention relies on disc springs to provide the restoring force. It employs a disc spring group composed of four sets of small disc springs, effectively controlling the friction of the small disc springs. Simultaneously, when the support is under tension, the second disc spring unit operates while the first disc spring unit remains inactive, further reducing the generation of additional friction. Similarly, when the support is under compression, the first disc spring unit operates while the second disc spring unit remains inactive, achieving the same effect.

[0029] 4. Strong fracture resistance. Since the first-order negative Poisson's ratio energy-dissipating core is always under stress as the support deformation increases, there is still a potential risk of fracture under large earthquakes and deformations. Even if the first-order negative Poisson's ratio energy-dissipating core fractures, the force flow can be transmitted from the I-shaped connecting pipe to the outer buckling-resisting sleeve via high-strength bolts, and then from the outer buckling-resisting sleeve to the other side of the I-shaped connecting pipe, providing a last line of defense.

[0030] 5. The bolt hole design allows the support to exhibit distinct energy dissipation time sequence characteristics under both compression and tension conditions. Specifically, the static hysteresis curve of this invention exhibits a clear double yield point characteristic, adapting to earthquakes of different magnitudes. Under minor earthquakes, it should remain elastic; that is, both the first-order and second-order negative Poisson's ratio energy-dissipating cores should be in an elastic state. Under moderate earthquakes, the first-order negative Poisson's ratio energy-dissipating core enters the plastic energy dissipation stage. Under major earthquakes, the I-shaped connecting pipe is tightly fitted to the second-order negative Poisson's ratio energy-dissipating core, causing the second-order negative Poisson's ratio energy-dissipating core to enter the plastic dissipation stage of earthquake energy.

[0031] 6. The support has a certain bending resistance. Under earthquake action, the two ends of the support may rotate, generating a bending moment in the middle of the support. At this time, the first disc spring unit on one side of the symmetrical disc spring assembly is compressed and the second disc spring unit on the other side is compressed, which can effectively resist the additional bending moment generated.

[0032] It should be understood that the implementation of any embodiment of the present invention does not mean that it will simultaneously possess or achieve multiple or all of the above-mentioned beneficial effects. Attached Figure Description

[0033] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0034] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0035] Figure 1 An exemplary three-dimensional diagram of a rectangular steel tube self-resetting graded energy-dissipating buckling restraint brace is shown;

[0036] Figure 2 An illustrative exploded view of a rectangular steel tube self-resetting graded energy-dissipating buckling restraint brace is shown;

[0037] Figure 3 An exemplary three-dimensional diagram of a rectangular steel tube self-resetting device with graded energy dissipation buckling restraint is shown;

[0038] Figure 4 An illustrative exploded view of a rectangular steel tube self-resetting device for a graded energy-dissipating buckling restraint brace is shown.

[0039] Figure 5 An exemplary three-dimensional diagram of a self-resetting connection device for a rectangular steel tube self-resetting graded energy-dissipating buckling restraint brace is shown;

[0040] Figure 6 An illustrative exploded view of a self-resetting connection device for a rectangular steel tube self-resetting graded energy-dissipating buckling restraint brace is shown.

[0041] Figure 7 An exemplary three-dimensional diagram of a first-order energy-dissipating inner core of a rectangular steel tube self-resetting graded energy-dissipating buckling restraint brace is shown.

[0042] Figure 8 An exemplary three-dimensional diagram of a second-order energy-dissipating inner core of a rectangular steel tube self-resetting graded energy-dissipating buckling restraint brace is shown.

[0043] Figure 9 An exemplary three-dimensional view of the outer rectangular buckling-resistance sleeve of a rectangular steel tube self-resetting graded energy-dissipating buckling-restrained brace is shown;

[0044] Figure 10 An exemplary three-dimensional diagram of a buckling-resistant fork rib of a rectangular steel tube self-resetting graded energy dissipation buckling restraint brace is shown.

[0045] Marked in the image:

[0046] First-order energy-consuming inner core 1, strip steel plate 11, round hole 111;

[0047] Second-order energy-consuming inner core 2, strip steel plate 21, oblong hole 211;

[0048] Rectangular steel pipe self-resetting device 3, rectangular steel pipe 31, round hole two 311, round hole three 312;

[0049] 4. Outer rectangular anti-buckling sleeve, 41. Box-type sleeve, 411. 412.

[0050] Self-resetting connection device 5, disc spring baffle 51, disc spring group 52, disc spring unit one 521, disc spring unit two 522, disc spring anchor 523;

[0051] Anti-bending rib 6;

[0052] High-strength bolt group 7;

[0053] High-strength bolt group 28.

[0054] In the various figures, the same or corresponding reference numerals indicate the same or corresponding parts. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0056] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; 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.

[0057] It should be understood that the terms "comprising / including," "consisting of," or any other variations are intended to cover non-exclusive inclusion, such that a product, apparatus, process, or method that comprises a list of elements includes not only those elements but may also include, where necessary, other elements not expressly listed, or elements inherent to such a product, apparatus, process, or method. Without further limitation, an element defined by the phrases "comprising / including," "consisting of," does not exclude the presence of additional identical elements in the product, apparatus, process, or method that includes said element.

[0058] It should also be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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 orientation, be constructed or operated in a specific orientation, and should not be construed as a limitation of the present invention.

[0059] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0060] The following is a detailed description of the specific implementation and preferred scheme of the self-resetting graded energy-dissipating buckling restraint brace for rectangular steel tubes proposed in this invention.

[0061] This invention studies a self-resetting graded energy-dissipating buckling restraint brace for rectangular steel tubes, such as... Figures 1-3 As shown, the main components include: a rectangular steel tube self-resetting device 3, a first-order energy-dissipating inner core 1, a second-order energy-dissipating inner core 2, and an outer rectangular buckling-restrained sleeve 4. The rectangular steel tube self-resetting device 3 serves as the main structure of the entire buckling-restrained brace, generating axial displacement and providing restoring force under stress, including axial tension and compression. The first-order energy-dissipating inner core 1 dissipates energy in the first order when the rectangular steel tube self-resetting device 3 generates axial displacement. The second-order energy-dissipating inner core 2 dissipates energy in the second order when predetermined conditions are met. The outer rectangular buckling-restrained sleeve 4 provides peripheral buckling restraint during first and second-order energy dissipation, while also assisting in force flow transfer and providing a final line of defense. Thus, through the first and second-order energy-dissipating inner cores and the self-resetting connection device, the mechanical properties of the brace are effectively improved, which will be elaborated in detail later.

[0062] In this invention, the rectangular steel pipe self-resetting device 3 is composed of two rectangular steel pipes 31 connected by a self-resetting connecting device 5. When subjected to force, the self-resetting connecting device 5 can generate axial displacement and provide a resetting force. The first-order energy-dissipating inner core 1 is set on the upper and lower sides of the two rectangular steel pipes 31 at the connection point. The second-order energy-dissipating inner core 2 is set on the left and right sides of the two rectangular steel pipes 31 at the connection point. The outer rectangular anti-buckling sleeve 4 is sleeved on the two rectangular steel pipes 31 at the connection point. The upper and lower sides are connected and fixed to the first-order energy-dissipating inner core 1 and the upper and lower sides of the two rectangular steel pipes 31, and the left and right sides are connected and fixed to the second-order energy-dissipating inner core 2 and the left and right sides of the two rectangular steel pipes 31. Furthermore, the first-order energy-dissipating inner core 1 and the rectangular steel pipe self-resetting device 3 are connected and fixed, that is, the two will not move or slide relative to each other. At the same time, the first-order energy-dissipating inner core 1 and the rectangular steel pipe self-resetting device 3 can slide axially with a first displacement relative to the second-order energy-dissipating inner core 2 and the outer rectangular anti-buckling sleeve 4. When the axial sliding of the first displacement reaches the predetermined condition, the first-order energy consumption performed by the first-order energy-consuming inner core 1 is converted into the second-order energy consumption performed by the second-order energy-consuming inner core 2.

[0063] In one specific embodiment, see Figures 4-6 A specific self-resetting connection device 5 is provided, including two oppositely arranged disc spring baffles 51 and a plurality of disc spring groups 52 installed on the two disc spring baffles 51. The two disc spring baffles 51 are respectively welded and fixed to the ends of two rectangular steel pipes 31. Specifically, they are welded to the ends of the two rectangular steel pipes 31 and to the upper and lower sides and the left and right side end edges of the rectangular steel pipes 31. While installing the self-resetting connection device 5, the connection strength and integrity of the ends of the rectangular steel pipes are enhanced.

[0064] More specifically, the disc spring group 52 is arranged in four groups, each group of disc spring group 52 includes one disc spring unit 521, two disc spring units 522, and one disc spring anchor 523. The disc spring anchor 523 is inserted into the two disc spring baffles 51, such as... Figures 5-6 As shown, each of the two disc spring baffles 51 has four through holes. The disc spring anchor 523 is a high-strength alloy disc spring anchor rod. The rod passes through the through holes of the two disc spring baffles 51. One disc spring unit 521 is sleeved on the rod between the two disc spring baffles 51. One disc spring unit 522 is sleeved on the rod on the outside of one disc spring baffle 51. The other disc spring unit 522 is sleeved on the rod on the outside of the other disc spring baffle 51. The two ends of the rod are anchored and fixed.

[0065] During installation, the four sets of disc springs 52 should first be pre-compressed and anchored to form a disc spring reset device, and then the disc spring reset device should be welded to the ends of the two rectangular steel pipes.

[0066] The disc spring baffle 51 can be a square, rectangular, or circular plate, or any other suitable shape. The number and size of the disc spring group 52 are determined according to design requirements. Disc spring unit 1 521 and disc spring unit 2 522 can be designed the same or different. As shown in the figure, disc spring unit 1 521 is designed to be longer than disc spring unit 2 522. In addition, the disc spring group should maintain central symmetry or axial symmetry to prevent the generation of additional bending moments.

[0067] In this invention, the disc spring reset device first provides self-resetting capability. As is well known, the reset force provided by a single disc spring is very limited; a larger reset force must be provided by stacking disc springs. However, stacking a large number of disc springs can cause an unpredictable increase in friction between the disc spring surfaces, leading to unpredictable support performance. This invention employs a disc spring group consisting of four sets of small disc springs, which can effectively control the friction of the small disc springs. Simultaneously, when the support is under tension, disc spring unit 2 522 operates while disc spring unit 1 521 does not operate, further reducing the generation of additional friction. Similarly, when the support is under compression, disc spring unit 1 521 operates while disc spring unit 2 522 does not operate, achieving the same effect.

[0068] In this invention, the disc spring reset device also enables the support to have a certain bending resistance. Since disc spring unit 522 is compressed when the entire support is under tension, and disc spring unit 521 is compressed when the entire support is under compression, considering that the actual connection between the support and the main structure is not completely fixed, meaning that both ends of the support have a certain rotational capacity, under earthquake action, if the entire support is compressed, for example, if the entire support is "bent" by the earthquake force, both ends of the support may rotate, generating a bending moment in the middle of the support. At this time, disc spring unit 521 in the middle of the symmetrical disc spring group is compressed, generating a rebound force that can effectively resist the generated additional bending moment.

[0069] See also Figures 2-4 , Figure 7 In one specific embodiment, the first-order energy-dissipating inner core 1 adopts two strip steel plates 11. The strip steel plates 11 are easy to lay on the rectangular steel pipe. The two strip steel plates 11 are respectively set on the upper and lower sides of the two rectangular steel pipes 31 at the butt joint. The two ends of the strip steel plates 11 are opened with round holes 111. The upper and lower sides of the two rectangular steel pipes 31 are respectively opened with round holes 211. The first-order energy-dissipating inner core 1 is connected to the rectangular steel pipe 31 by a group of high-strength bolts 7 passing through the round holes 111 and round holes 211.

[0070] By opening round holes at both ends of the strip steel plate 11 and the upper and lower sides of the rectangular steel pipe 31, and connecting and fixing the two with high-strength bolt group 7, the first-order energy-dissipating inner core 1 is simultaneously subjected to tension or compression when the rectangular steel pipe 31 is subjected to tension or compression. The first-order energy-dissipating inner core 1 participates in energy dissipation first and in a timely manner, that is, first-order energy dissipation. It maintains an elastic state under small earthquakes and enters the plastic energy dissipation stage under moderate earthquakes.

[0071] Preferably, the first-order energy-dissipating inner core 1 can be made of high-ductility materials such as low-yield-point steel, aluminum alloy, and shape memory alloy.

[0072] Furthermore, to provide better energy dissipation capacity, a weakening zone is formed in the middle of the strip steel plate 11. Specifically, alternating horizontal and vertical perforations are made on the strip steel plate 11 to create a negative Poisson's ratio effect. The alternating horizontal and vertical perforations are arranged in multiple rows and columns, with one horizontal perforation alternating with one vertical perforation in the same row, and one vertical perforation alternating with one horizontal perforation in the same column. By designing the weakening method of perforations in the middle weakening zone and designing a reasonable opening ratio, a lightweight design is achieved, reducing the self-weight while realizing the negative Poisson's ratio effect of the component. This makes the inner core exhibit lateral contraction characteristics under stress, thus avoiding buckling instability caused by lateral expansion in traditional structures and achieving a buckling-free effect. At the same time, the negative Poisson's ratio characteristic makes the core component more ductile, improving the ductility and durability of the component, and maintaining stable performance under multiple seismic loading. In addition, this characteristic optimizes the energy dissipation mechanism and improves the energy absorption and seismic resistance of the structure under extreme loads. At the same time, by changing the cross-sectional shape of this area to make its load-bearing capacity lower than that of the end connection area, plastic deformation is effectively guided to occur in the middle of the component, preventing excessive plastic deformation or damage in other areas, thereby improving the energy dissipation capacity of the system.

[0073] The opening ratio of the peanut-shaped structure is determined according to the design requirements. If the opening ratio is too small, the negative Poisson's ratio effect will be difficult to reflect. If the opening ratio is too large, the structural strength will be difficult to guarantee. Studies have shown that an opening ratio of 40-50% is appropriate, that is, a solid ratio of 50-60% is a reasonable range.

[0074] Of course, in addition to peanut-shaped holes, elliptical holes, star-shaped holes, and other types of holes can also be used to make the inner core have negative Poisson bit properties.

[0075] See also Figures 2-4 , Figure 8 In one specific embodiment, the second-order energy-dissipating inner core 2 also adopts two strip steel plates 21. The two strip steel plates 21 are respectively set on the left and right sides of the two rectangular steel pipes 31 at the butt joint. The two ends of the strip steel plates 21 are opened with elongated holes 211, and the left and right sides of the two rectangular steel pipes 31 are opened with corresponding round holes 312. The second-order energy-dissipating inner core 2 is connected to the rectangular steel pipes 31 by high-strength bolts 28 passing through the elongated holes 211 and the round holes 312.

[0076] As previously described, by opening elongated holes 211 at both ends of the strip steel plate 21 and connecting it to the rectangular steel pipe 31 with a group of high-strength bolts 8, the first-order energy-dissipating inner core 1 enters the plastic energy-dissipating stage under moderate earthquakes. Under moderate and severe earthquakes, the self-resetting device 3 of the rectangular steel pipe and the first-order energy-dissipating inner core 1 generate a relative sliding with respect to the second-order energy-dissipating inner core 2 within the stroke of the elongated holes 211, and are then tightened by the bolts. At this time, the second-order energy-dissipating inner core 2 dissipates energy. It should be noted that the time for the second-order energy-dissipating inner core 2 to participate in the stress is determined by the length of the elongated holes and can be flexibly adjusted according to actual needs.

[0077] The bolt hole opening method described above can make the support exhibit obvious energy dissipation time sequence characteristics under both compression and tension. Under minor earthquakes, it should remain elastic, that is, the first and second order energy dissipation cores should be in an elastic state. Under moderate earthquakes, the first order energy dissipation cores enter the plastic energy dissipation stage. Under major earthquakes, the second order energy dissipation cores enter the plastic dissipation of seismic energy.

[0078] The strip steel plate 21 used in the second-order energy-consuming inner core 2 also forms a weakening zone in the middle. The specific weakening method is the same as that of the first-order energy-consuming inner core 1, but the opening size and opening ratio of the peanut hole are reasonably determined according to the actual situation.

[0079] Preferably, the second-order energy-dissipating inner core 2 can be made of high-ductility materials such as low-yield-point steel, aluminum alloy, and shape memory alloy.

[0080] See also Figure 1 , Figure 2 , Figure 9 In one specific embodiment, the outer rectangular buckling-resisting sleeve 4 adopts a box-shaped sleeve 41. The box-shaped sleeve 41 is sleeved on the two rectangular steel pipes 31 at the butt joint. The top and bottom ends of the box-shaped sleeve 41 are provided with elongated holes 411 corresponding to the first round hole 111 and the second round hole 311. The outer rectangular buckling-resisting sleeve 4 is connected to the first-order energy-dissipating inner core 1 and the rectangular steel pipe self-resetting device 3 by passing through the elongated holes 411, the first round hole 111 and the second round hole 311 through the group of high-strength bolts 7. At the same time, elongated holes 412 corresponding to the first round hole 211 and the third round hole 312 are provided on the left and right sides of the box-shaped sleeve 41. The outer rectangular buckling-resisting sleeve 4 is connected to the second-order energy-dissipating inner core 2 and the rectangular steel pipe self-resetting device 3 by passing through the elongated holes 412, the first round hole 211 and the third round hole 312 through the group of high-strength bolts 8.

[0081] The outer rectangular buckling-resistant sleeve 4 provides better fracture resistance. Since the first-order energy-dissipating inner core is always under stress when the support deformation continues to increase, there is still a potential risk of fracture under large earthquake and large deformation. Even if the first-order energy-dissipating inner core fractures, the force flow can be transmitted from the rectangular steel pipe to the box-type sleeve through the high-strength bolts, and then from the box-type sleeve to the rectangular steel pipe on the other side, providing the last line of defense.

[0082] In this invention, the elongated holes 412 on both sides of the box-shaped sleeve 41 are longer than the elongated holes 211 at both ends of the strip steel plate 21. Thus, when both the first-order energy-dissipating inner core 1 and the second-order energy-dissipating inner core 2 enter a plastic state during a major earthquake, the rectangular steel pipe self-resetting device 3 and the first-order and second-order energy-dissipating inner cores 1 and 2, within the stroke of the elongated holes 412, generate a relative sliding motion with respect to the outer rectangular buckling-resistance sleeve 4. This is then tightened by bolts, providing a final line of defense. It should be noted that the time during which the outer rectangular buckling-resistance sleeve 4 participates in the stress is determined by the length of the elongated holes and can be flexibly adjusted according to actual needs.

[0083] Furthermore, in this invention, the first-order energy-dissipating inner core 1 continues to be stressed when entering the second-order energy dissipation stage. Preferably, the strip steel plate 11 of the first-order energy-dissipating inner core 1 is designed to be longer than the strip steel plate 21 of the second-order energy-dissipating inner core 2, with the longer length to cope with large deformation. At the same time, the first-order energy-dissipating inner core 1 has a limited bearing capacity, or it may fracture earlier than the expected deformation due to initial defects. The deformation at the time of fracture of the first-order energy-dissipating inner core 1 is larger. The purpose of the outer rectangular buckling-resistant sleeve 4 is to constrain and prevent fracture, replacing the first-order energy-dissipating unit 1 of the inner core. Therefore, the elongated holes 411 at the top and bottom of the box-shaped sleeve 41 are longer than the elongated holes 412 on the left and right sides, in order to accommodate the larger deformation at the time of fracture of the first-order energy-dissipating inner core 1.

[0084] See last. Figure 3 , Figure 10 The rectangular steel pipe self-resetting device 3 is also equipped with anti-bending fork ribs 6 at the butt joint. Four sets of anti-bending fork ribs 6 are welded together from all four sides between the two disc spring baffles 51.

[0085] Specifically, each set of anti-buckling fork ribs 6 is formed by two semi-trapezoidal structures interlocking with each other, that is, the two semi-trapezoidal structures interlock with each other and are welded and fixed to the disc spring baffles 51 on both sides respectively, forming a similar overall trapezoidal structure.

[0086] This invention will pre-assemble Figure 6 The disc spring reset device shown is preloaded and anchored, forming a shape as follows: Figure 5 The disc spring reset device shown is then welded to the ends of two rectangular steel tubes 31 to form a rectangular steel tube self-resetting device 3. Finally, the anti-buckling fork rib 6 is welded to the rectangular steel tube self-resetting device 3. Simultaneously, the first-stage energy-dissipating inner core 1, the second-stage energy-dissipating inner core 2, and the outer rectangular anti-buckling sleeve 4 are fabricated, with round and oblong holes drilled at appropriate locations. All the above installation steps should be completed in the prefabrication plant; on-site connection only requires high-strength bolts.

[0087] In summary, the self-resetting graded energy-dissipating buckling restraint brace for rectangular steel tubes provided by this invention exhibits the following working characteristics:

[0088] In the initial stage (small earthquake), the support mainly exhibits elastic deformation. The rectangular steel pipe self-resetting device 3 is under force. Both the first-order energy-dissipating inner core and the second-order energy-dissipating inner core are in an elastic state. The disc spring reset device provides the reset force. At this time, the second-order energy-dissipating inner core has an allowable sliding stroke due to the use of a long oval hole connection. The second-order energy-dissipating inner core does not participate in energy dissipation within this sliding stroke.

[0089] During a moderate earthquake, the first-order energy-dissipating core begins to yield, providing plastic energy dissipation capacity, while the self-resetting unit continues to function. At this time, the second-order energy-dissipating core participates in energy dissipation, or has not yet reached the energy dissipation stage of the second-order energy-dissipating core.

[0090] During a major earthquake, the energy-dissipating components fully dissipate energy, and both the first-order and second-order energy-dissipating inner cores yield. The inner cores enter the plastic stage and generate residual deformation. The outer rectangular buckling-resisting sleeve 4 participates in the work, providing external constraints to prevent fracture. The disc spring reset device can prevent or reduce excessive residual deformation of the support, while mitigating structural damage and quickly restoring structural function after the earthquake.

[0091] Using the buckling restraint brace of the present invention, inter-story deformation can be effectively coordinated through reasonable design. That is, buildings with traditional buckling restraint braces have obvious weak stories, and the weak stories have a higher risk of failure under major earthquakes. However, buildings with the present invention can effectively avoid the weak story effect by reasonably designing the brace of each story.

[0092] All welding processes in this invention can be completed in a prefabrication plant, which produces standard "modules." On-site construction only requires positioning the modules according to pre-drilled bolt holes and assembling them with high-strength bolts to complete the structural installation, resulting in a highly modular design. This "building block" construction concept reduces labor usage, lowers construction difficulty, and effectively shortens the construction cycle.

[0093] This invention can be applied to single-story buildings, or it can be combined with detachable and replaceable shear walls, energy-dissipating supports, etc., to form a frame-shear wall system or a frame-support system, which can be flexibly applied to multi-story and high-rise building systems.

[0094] While several specific implementation details are included in the foregoing discussion, these should not be construed as limiting the scope of the invention. Certain features described in the context of individual 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 individually or in any suitable sub-combination in multiple implementations.

Claims

1. A self-resetting graded energy-dissipating buckling restraint brace for rectangular steel tubes, characterized in that, Mainly includes: A rectangular steel pipe self-resetting device is composed of two rectangular steel pipes connected by a self-resetting connecting device. When subjected to force, the rectangular steel pipe self-resetting device can generate axial displacement and provide a resetting force through the self-resetting connecting device. The first-order energy-dissipating inner core is connected and fixed to the upper and lower sides of the two rectangular steel tubes at the docking joint. The second-order energy-dissipating inner core is connected and fixed to the left and right sides of the two rectangular steel tubes at the docking joint. The outer rectangular buckling-resisting sleeve is fitted onto the two rectangular steel pipes at the butt joint. Its upper and lower sides are connected and fixed to the upper and lower sides of the first-stage energy-dissipating inner core and the two rectangular steel pipes, and its left and right sides are connected and fixed to the second-stage energy-dissipating inner core and the left and right sides of the two rectangular steel pipes. The first-order energy-dissipating inner core and the rectangular steel pipe self-resetting device can produce an axial sliding with a first displacement relative to the second-order energy-dissipating inner core and the outer rectangular anti-buckling sleeve.

2. The buckling-restrained brace according to claim 1, characterized in that, The self-resetting connection device includes two oppositely arranged disc spring baffles and multiple disc spring groups installed on the two disc spring baffles. The two disc spring baffles are respectively welded and fixed to the ends of two rectangular steel pipes.

3. The buckling-restrained brace according to claim 2, characterized in that, Each of the multiple disc spring groups includes a disc spring unit one, two disc spring units two, and a disc spring anchor. The disc spring anchor is inserted through two disc spring baffles. One disc spring unit is fitted onto the disc spring anchor between the two disc spring baffles, and the two disc spring units two are respectively fitted onto the disc spring anchors outside the two disc spring baffles.

4. The buckling-restrained brace according to claim 1, characterized in that, The first-order energy-dissipating inner core uses two rectangular steel plates. The two rectangular steel plates are respectively set on the upper and lower sides of the two rectangular steel tubes at the butt joint. A weakening zone is formed in the middle of the two rectangular steel plates. Circular holes are opened at both ends. Circular holes are opened on the upper and lower sides of the two rectangular steel tubes respectively. They are connected by a group of high-strength bolts. And / or, the second-order energy-dissipating inner core adopts two shaped steel plates, which are respectively set on the left and right sides of the two rectangular steel pipes at the butt joint, and a weakening zone is formed in the middle of the two shaped steel plates. The two ends are opened with elongated holes, and the left and right sides of the two rectangular steel pipes are respectively opened with round holes, which are connected by a group of high-strength bolts.

5. The buckling-restrained brace according to claim 4, characterized in that, The weakening region is provided with peanut-shaped holes arranged in an alternating horizontal and vertical array to create a negative Poisson's ratio effect.

6. The buckling-restrained brace according to claim 4, characterized in that, The outer rectangular anti-buckling sleeve adopts a box-shaped sleeve that is fitted onto the two rectangular steel pipes at the butt joint. The box-shaped sleeve has elongated holes 2 on the upper and lower sides corresponding to the first and second round holes, and is connected by a group of high-strength bolts. At the same time, the box-shaped sleeve has elongated holes 3 on the left and right sides corresponding to the first and third round holes, and is connected by a group of high-strength bolts.

7. The buckling-restrained brace according to claim 6, characterized in that, The third elongated hole is longer than the first elongated hole, allowing the rectangular steel pipe self-resetting device and the first-order energy-dissipating inner core and the second-order energy-dissipating inner core to slide axially with a second displacement relative to the outer rectangular anti-buckling sleeve.

8. The buckling-restrained brace according to claim 6, characterized in that, The second elongated hole is longer than the third elongated hole, and the first-order energy-consuming inner core is longer than the second-order energy-consuming inner core.

9. The buckling-restrained brace according to claim 2, characterized in that, The rectangular steel pipe self-resetting device is also provided with anti-bending fork ribs at the butt joint, and four sets of the anti-bending fork ribs are welded together from all four sides between the two disc spring baffles.

10. The buckling-restrained brace according to claim 9, characterized in that, Each set of anti-buckling ribs is formed by two semi-trapezoidal structures interlocking with each other.

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