A multi-stage force-bearing anti-collapse buckling-restrained brace

Abstract

The present invention discloses a multi-stage force-bearing buckling-restrained brace, comprising: a buckling-free energy dissipation core, an upper connection end, a lower connection end, a spare tension rod system, a spare force-transferring restraint outer tube, and an elastic cushion block; both ends of the buckling-free energy dissipation core are welded to the upper connection end and the lower connection end respectively. The spare force-transferring restraint outer tube includes a tube body and a strengthening end. There is an elastic cushion block between the strengthening end and the upper and lower connection ends and they are connected through the spare tension rod system. The height of the elastic cushion block is less than the inner clearance value between the strengthening end and the upper and lower connection ends, and the length of the spare tension rod system is significantly greater than the distance between the outer surfaces of the strengthening end and the upper and lower connection ends. The beneficial effects achieved by the present invention are as follows: The multi-stage force-bearing buckling-restrained brace provides multi-stage lateral resistance performance for the structure. After the buckling-free energy dissipation core exceeds the deformation limit value, the stiffness and bearing capacity of the brace can be greatly increased, improving the anti-collapse performance of the structure under strong earthquake actions.

Description

Technical Field

[0001] The present invention belongs to the technical field of civil engineering structures, and particularly relates to a multi-stage force-bearing anti-collapse buckling-restrained brace. Technical Background

[0002] Earthquakes are frequent natural disasters, and seismic performance of engineering structures needs to be considered in engineering construction in seismic active areas. By arranging buckling-restrained braces in the structural system, the seismic performance of the structure can be improved well. The buckling-restrained brace remains elastic under normal use or small earthquake scenarios and can be used as an ordinary brace to provide the necessary lateral stiffness for the structure. Under medium and large earthquakes, the buckling-restrained brace enters the yield state, dissipates seismic energy through the plastic deformation of the metal, reduces the seismic response of the structure, and reduces the internal force demand of structural members.

[0003] Generally, a buckling-restrained brace mainly consists of a core energy dissipation component, a filling material, and a restraint component, while a fully metal buckling-restrained brace has no filling material. The filling material and the restraint component limit the buckling behavior of the core energy dissipation component in the compression state, enabling the core energy dissipation component to obtain approximately the same tensile and compressive yield behaviors, and thus obtaining a stable cyclic hysteretic behavior.

[0004] In recent years, the performance of structures under small earthquakes has also received attention. Therefore, multi-stage yield buckling-restrained braces have begun to be proposed, which are made by connecting a damper with a smaller bearing capacity in parallel on the basis of the original buckling-restrained brace. Under small earthquakes, the damper with a smaller bearing capacity yields and dissipates energy first, while the main buckling-restrained brace remains elastic. Under medium and large earthquakes, the buckling-restrained brace and the small damper yield and dissipate energy simultaneously.

[0005] In recent years, earthquake damage data shows that the seismic intensity actually encountered by actual structures may far exceed the design seismic intensity, resulting in seismic responses of structures such as inter-story lateral displacement far exceeding the design values. At the same time, due to the inherent properties of metal materials, the stiffness of the buckling-restrained brace after yielding decreases significantly compared to the elastic stage, which makes the structure very prone to weak story failure. On the other hand, as the lateral deformation of the structure increases continuously, the second-order gravity effect also increases continuously, while the lateral stiffness of the structural system using conventional buckling-restrained braces remains basically unchanged or even decreases, which is very unfavorable for the anti-overturning performance of the structure. Summary of the Invention

[0006] The present invention aims to propose a multi-stage force-bearing buckling-restrained brace with simple structure and low cost to solve the problem of low stiffness after yielding of ordinary buckling-restrained braces in the above technical background, which can improve the lateral stiffness of the structural system under large deformations, inhibit the weak story failure mechanism of the structure, and improve the anti-collapse performance of engineering structures.

[0007] To this end, the present invention proposes a multi-stage force-bearing buckling-restrained brace. This multi-stage force-bearing buckling-restrained brace is an improvement on the ordinary buckling-restrained brace. Compared with the ordinary buckling-restrained brace, the cost increase is very small, but the material utilization rate is further improved. It can degenerate into an ordinary brace when the structural deformation is large, improving the lateral stiffness of the structure.

[0008] To achieve the above object, the technical solution of the present invention is as follows:

[0009] A multi-stage force-bearing anti-collapse buckling-restrained brace, the structural characteristics of which are characterized in that the brace includes: a non-buckling energy-dissipating core (1), a standby force-transferring restraint outer tube (5), and a buckling-preventing filling material (7). The non-buckling energy-dissipating core (1) is placed inside the standby force-transferring restraint outer tube (5), and a buckling-preventing filling material (7) is provided inside the standby force-transferring restraint outer tube (5). It also includes an upper connection end (2), a lower connection end (3), a standby tie rod system (4), and an elastic cushion block (6); the upper and lower ends of the non-buckling energy-dissipating core (1) are respectively welded to the upper and lower connection ends (2, 3).

[0010] The standby force-transferring restraint outer tube (5) includes a tube body (51) and at least one strengthening end (52), and the standby tie rod system (4) includes bolt fasteners (41), rigid tie rods (42), and elastic components (43);

[0011] One end of the standby tie rod system (4) is connected to the upper connection end (2) or the lower connection end (3), and the other end is connected to the strengthening end (52). Moreover, the rigid tie rod (42) should extend out of the outer surface of the connected upper connection end (2) or lower connection end (3), and also extend out of the outer surface of the corresponding strengthening end (52). The elastic component (43) is placed in the redundant length interval obtained by the rigid tie rod (42) extending out of the outer surface of the component it is connected to.

[0012] The standby force-transferring restraint outer tube (5) has a strengthening end (52) at least at one end, and is connected to one of the upper and lower connection ends (2, 3) through the standby tie rod system (4). An elastic cushion block (6) is provided in the connection gap, and it is ensured that the connection gap is larger than the height of the elastic cushion block (6). The elastic cushion block (6) can be fixedly connected to one of the strengthening end (52) or the corresponding upper and lower connection ends (2, 3).

[0013] The strengthening end (52) of the standby force-transferring restraint outer tube (5) is a square thick plate, and is connected to the tube body (51) by welding. Stiffening ribs (53) are welded to at least two opposite outer surfaces of the tube body (51). Round holes (521) are opened between the stiffening ribs (53) of the strengthening end (52), and the rigid tie rod (42) passes through the round holes (521).

[0014] As an alternative, the spare force transfer restraint outer tube (5) has a reinforcing end (52) only at one end, and the end without the reinforcing end (52) is fixedly connected to either the upper connecting end (2) or the lower connecting end (3).

[0015] The buckling - resistant filling material (7) fills the interior of the spare force transfer restraint outer tube (5) and is in direct contact with the inner surface of the spare force transfer restraint outer tube (5). The inner surface of the spare force transfer restraint outer tube (5) is flat and has the dual functions of providing restraint and bearing force.

[0016] As an alternative, the buckling - resistant filling material (7) fills the interior of the buckling - resistant sleeve (54). The buckling - resistant filling material (7) is in direct contact with the interior of the buckling - resistant sleeve (54). The spare force transfer restraint outer tube (5) wraps the buckling - resistant sleeve (54), and the two can have relative slip. There is a micro - gap between the outer surface of the buckling - resistant sleeve (54) and the inner surface of the spare force transfer restraint outer tube (5). Guide groove stiffeners (541) are provided in four orthogonal directions on the inner surface of at least one end of the spare force transfer restraint outer tube (5), and the guide groove stiffeners (541) are located at the same end as the reinforcing end (52); the spare force transfer restraint outer tube (5) has the triple functions of providing restraint, bearing, and energy dissipation.

[0017] The present invention is arranged diagonally within one span of a building, connecting one end to the top corner and the other end to the bottom corner. When inter - story deformation occurs in the building, the specific working mechanism and achievable beneficial effects of the present invention are as follows:

[0018] When the structure bears the seismic action within the design expectation and the brace is in tension, the non - buckling energy - dissipating core (1) will undergo tensile deformation, and the upper and lower connecting ends (2, 3) and the reinforcing end (52) have a tendency to move apart. When the upper and lower connecting ends (2, 3) and the reinforcing end (52) are simultaneously connected through the spare tie - rod system (4), since the rigid tie - rod (42) of the spare tie - rod system (4) in the present technical solution extends out of the outer surfaces of the upper and lower connecting ends (2, 3) and the reinforcing end (52), and an elastic component (43) is placed in the extended redundant length interval; at this stage, the elastic component (43) can undergo significant elastic compression deformation. Therefore, the separation movement of the upper and lower connecting ends (2, 3) and the reinforcing end (52) is basically unobstructed. The non - buckling energy - dissipating core (1) has a free deformation space at this stage, and due to the tensile bearing capacity generated by the compression deformation of the elastic component (43), it is transmitted to the upper and lower connecting ends (2, 3) through the bolt fasteners (41), the rigid tie - rod (42), and the spare force transfer restraint outer tube (5), improving the tensile bearing capacity of the multi - stage force - bearing buckling - restrained brace of the present invention in the free deformation stage and making up for the pressure - increasing effect caused by the Poisson effect and friction force of the ordinary buckling - restrained brace.

[0019] Due to the limited length of the spare tie rod system (4) in this technical solution, the compression deformation ability of the elastic component (43) is limited, which restricts the tensile deformation of the buckling-free energy dissipation core (1) to a certain extent. Therefore, when the structure is subjected to a strong earthquake, when the tensile deformation of the buckling-free energy dissipation core (1) exceeds the reserved value, the elastic component (43) is completely compressed and cannot further undergo significant compression deformation. Therefore, the separation movement of the upper and lower connection ends (2, 3) and the strengthening end (52) is blocked, and the second tensile load-bearing mechanism composed of the upper and lower connection ends (2, 3), the spare tie rod system (4), and the spare force transmission constraint outer tube (5) is formed, enhancing the tensile bearing capacity and stiffness of the support, suppressing the emergence of weak layers in the structure, and improving the anti-collapse ability of the structure.

[0020] When the structure is subjected to an earthquake within the design expectation and the support is under compression, the buckling-free energy dissipation core (1) will undergo compression deformation, and the upper and lower connection ends (2, 3) and the strengthening end (52) have a tendency to move closer to each other. When elastic pads (6) are simultaneously arranged between the upper and lower connection ends (2, 3) and the strengthening end (52), due to the thickness of the elastic pads (6) in this technical solution being less than the clearance value between the upper and lower connection ends (2, 3) and the strengthening end (52), the relative movement of the upper and lower connection ends (2, 3) and the strengthening end (52) in this stage is not blocked, and the buckling-free energy dissipation core (1) has a free compression deformation space. In this stage, the proposed multi-stage force-bearing buckling-restrained brace is no different from the ordinary buckling-restrained brace.

[0021] Due to the certain thickness of the elastic pads (6) in this technical solution, the minimum distance between the upper and lower connection ends (2, 3) and the strengthening end (52) is restricted to a certain extent. Therefore, when the structure is subjected to a strong earthquake, when the compression deformation of the buckling-free energy dissipation core (1) exceeds the reserved value, the elastic pads (6) start to bear pressure, and the second compression load-bearing mechanism composed of the upper and lower connection ends (2, 3), the elastic pads (6), and the spare force transmission constraint outer tube (5) is formed, enhancing the compressive bearing capacity and stiffness of the support, suppressing the emergence of weak layers in the structure, and improving the anti-collapse ability of the structure. Due to the certain deformation ability of the elastic pads (6), the impact effect when the upper and lower connection ends (2, 3) contact the elastic pads (6) is alleviated, and the stiffness of the second compression load-bearing mechanism is reduced to a certain extent, further balancing the stiffness difference with the second tensile load-bearing mechanism.

[0022] The multi-stage force-bearing buckling-restrained brace proposed by the present invention has a second tensile load-bearing mechanism and a second compressive load-bearing mechanism, which can effectively improve the inter-story lateral stiffness of the structure when the lateral deformation is large, control the maximum inter-story displacement of the structure, and inhibit the failure mechanism of weak stories. Even if the buckling energy-dissipating core (1) undergoes fatigue fracture under extremely strong earthquakes, the second tensile load-bearing mechanism and the second compressive load-bearing mechanism can still play a role, providing a strong lateral resistance capacity for the structural system in the near-collapse stage and enhancing the anti-collapse performance.

[0023] When the structure is subjected to earthquake actions within the design expectation, the spare force-transferring restraint outer tube (5) in the multi-stage force-bearing buckling-restrained brace of the present invention serves as a restraint member to provide lateral restraint for the buckling energy-dissipating core (1). When the structure is subjected to strong earthquake actions, the spare force-transferring restraint outer tube (5) serves as both a restraint member and a force-bearing member to bear tensile or compressive forces. Compared with existing solutions, the multi-stage force-bearing buckling-restrained brace proposed by the present invention further improves the material utilization rate. And since the spare force-transferring restraint outer tube (5) is a part of the second tensile mechanism, the tensile stiffness of the second tensile load-bearing mechanism is improved compared with existing solutions, further balancing the stiffness difference with the second compressive load-bearing mechanism. Description of the Drawings

[0024] Figure 1 The first structural schematic diagram of the multi-stage force-bearing buckling-restrained brace for the embodiment;

[0025] Figure 2 The schematic diagram of the spare tension rod system provided by the embodiment;

[0026] Figure 3 The schematic diagram of the strengthened end of the spare force-transferring restraint outer tube provided by the embodiment;

[0027] Figure 4 The schematic diagram of the lower connection end of the buckling energy-dissipating core provided by the embodiment;

[0028] Figure 5 The elastic cushion block provided by the embodiment;

[0029] Figure 6 The front view of the first optional structure of the present invention;

[0030] Figure 7 The second optional structural schematic diagram of the present invention;

[0031] Figure 8 The schematic diagram of an application mode of the first structure of the present invention;

[0032] Figure 9 The schematic diagram of a second application mode of the first structure of the present invention;

[0033] Figure 10 Schematic diagram of a non-flexural energy dissipation core structure provided by an embodiment of the present invention;

[0034] Figure 11 Schematic diagram of the application scenario of a multi-stage force-bearing buckling-restrained brace in the embodiment;

[0035] Figure 12 Schematic sectional view of the mechanism of the second force-bearing mechanism of the present invention

[0036] Figure 13 Schematic diagram of the force-displacement curve of the present invention under normal working conditions

[0037] In the figure: 1 non-flexural energy dissipation core; 11 end strengthening area; 12 intermediate energy dissipation area;

[0038] 2 upper connection end;

[0039] 3 lower connection end; 31 dividing plate; 32 through plate; 33 connection end plate;

[0040] 4 spare tie rod system; 41 bolt fastener; 42 rigid tie rod; 43 elastic component;

[0041] 5 spare force transfer restraint outer tube; 51 tube body; 52 strengthening end; 53 stiffening rib; 54 buckling restraint sleeve; 521 round hole; 541 guide groove stiffening rib;

[0042] 6 elastic cushion block; 61 circular hole; 62 cross-shaped hole;

[0043] 7 buckling restraint filling material;

[0044] 8 frame beam;

[0045] 9 frame column. Detailed implementation manners

[0046] The technical solution of the present invention will be further described below in conjunction with the embodiments and the drawings. Those familiar with this technology can easily understand the advantages and effects of the present invention from the content disclosed in this specification.

[0047] In view of the fact that the existing buckling-restrained brace has a low stiffness after yielding and cannot provide strong lateral stiffness for the structure when the structure deforms greatly. At the same time, the disclosed solutions have the problem of large differences in tensile and compressive stiffness. The present invention provides a new technical solution. By reasonably utilizing the rigid tie rod and the buckling restraint outer tube, a multi-stage force-bearing buckling-restrained brace is formed. The difference in tensile and compressive stiffness of this technical solution is alleviated, and it is highly economical. It can be used for the manufacture of new braces and the transformation of existing ordinary buckling-restrained braces.

[0048] In this embodiment, as Figure 1As shown, the multi-stage force-bearing buckling-restrained brace includes a buckling-free energy dissipation core (1), an upper connection end (2), a lower connection end (3), a spare tie rod system (4), a spare force-transferring restraint outer tube (5) and the buckling prevention filling material (7) inside it, and an elastic cushion block (6).

[0049] Furthermore, the typical structure of the buckling-free energy dissipation core (1) is as shown in Figure 10 and is made of steel with a yield point and good low ductility. The buckling-free energy dissipation core (1) needs to include an end strengthening area (11) and an intermediate energy dissipation area (12). The cross-section of the end strengthening area (11) is significantly larger than the area of the intermediate energy dissipation area (12), which ensures that plastic deformation only occurs in the intermediate energy dissipation area (12). The buckling-free energy dissipation core (1) is fixedly connected to the upper and lower connection ends (2, 3) by welding at both ends. In the first application mode of the first structure of the provided embodiment, the intermediate energy dissipation area (12) is wrapped with a non-bonding material and placed in the inner cavity of the spare force-transferring restraint outer tube (5), and the buckling prevention filling material (7) fills the entire inner cavity of the spare force-transferring restraint outer tube (5), as specifically shown in Figure 8 .

[0050] Furthermore, as shown in Figure 2 , the spare tie rod system (4) includes two bolt fasteners (41); a rigid tie rod (42); two elastic components (43). The elastic components (43) are generally disc springs or high-load-bearing springs, or other equivalent alternative products. The spare tie rod system (4) is used to connect the strengthening end (52) to the lower connection end (3), or is used to connect the strengthening end (52) to the upper and lower connection ends (2, 3) simultaneously.

[0051] Furthermore, as shown in Figure 5 , the elastic cushion block (6) is made of a rubber block for structural load-bearing, and is provided with circular holes (61) and cross-shaped holes (62) on the surface.

[0052] Furthermore, the length of the spare force-transferring restraint outer tube (5) is less than the net distance between the upper connection end (2) and the lower connection end (3), that is, there is a gap between at least one reinforcing end (52) and its nearest upper connection end (2) or lower connection end (3). The spare tie rod system (4) extends out of the outer surfaces of the upper connection end (2) or the lower connection end (3) to which it is connected and the corresponding reinforcing end (52), and has a considerable redundant length. An elastic member (43) is placed in this redundant length range. The total redundant length of each rigid tie rod (42) is 0.01 times the total support length divided by the number of reinforcing ends (52). The thickness of the elastic cushion block (6) is smaller than the thickness of the gap between the reinforcing end (52) on both sides of it and the corresponding upper connection end (2) or lower connection end (3), and the difference between the two is approximately equal to 0.01 times the total support length of the present invention divided by the number of reinforcing ends (52).

[0053] Under the guidance of the technical means disclosed in the present invention, Figure 1 、 Figure 6 In the shown embodiment, the upper connection end (2) and the lower connection end (3) have the same structure, and the spare tie rod system (4) exists at both the upper and lower ends of the support. Taking the lower connection end (3) as an example, as Figure 4 shown, the lower connection end (3) includes a dividing plate (31), a through plate (32), and a connection end plate (33). Bolt holes are provided on the dividing plate (31) and the through plate (32) for connecting to the structural frame. Bolt holes are provided on the connection end plate (33) for connecting to the spare tie rod system (4).

[0054] In Figure 1 、 Figure 6 In the shown embodiment, the tube body (51) of the spare force-transferring restraint outer tube (5) is a square steel tube, and reinforcing ends (52) are provided at both the upper and lower ends. As Figure 3 shown, the reinforcing end (52) is welded to the tube body (51), and a number of stiffening ribs (53) are provided on the outside. The reinforcing end (52) is provided with a round hole (521) for connecting to the spare tie rod system (4).

[0055] In Figure 1 、 Figure 6In the illustrated embodiment, the spare force-transfer restraint outer tube (5) has the same reinforcing end heads (52) at both the upper and lower ends; the upper connection end head (2) and the lower connection end head (3) have the same structure; the buckling-free energy dissipation core (1) is centered and aligned with the spare force-transfer restraint outer tube (5) and the buckling-restrained filling material (7), and is anchored at the midpoint position to prevent the spare force-transfer restraint outer tube (5) and the internal buckling-restrained filling material (7) from freely slipping relative to the buckling-free energy dissipation core (1). The upper connection end head (2) and the lower connection end head (3) are respectively connected to their nearest reinforcing end heads (52) through the spare tie rod system (4), and elastic pads (6) are arranged in the connection gap x3 (see Figure 12 -b).

[0056] As an alternative structural solution, as shown in Figure 7 , the connection end plate of the upper connection end head (2) can be free of bolt holes, and at the same time, the spare force-transfer restraint outer tube (5) can be provided with a reinforcing end head (52) only at one end. The end of the spare force-transfer restraint outer tube (5) with the reinforcing end head (52) is connected to the lower connection end head (3) through the spare tie rod system (4) and the elastic pad (6); the end of the spare force-transfer restraint outer tube (5) without the reinforcing end head (52) is fixedly connected to the upper connection end head (2) by welding. At the same time, the buckling-free energy dissipation core (1) does not need to be anchored to the spare force-transfer restraint outer tube (5) at the midpoint.

[0057] As shown in Figure 9 , as an alternative application mode of the structural solution one of the embodiments of the present invention, the buckling-free energy dissipation core (1) passes through the internal cavity of the buckling-restrained sleeve (54), the buckling-restrained filling material (7) fills the inside of the buckling-restrained sleeve (54), the spare force-transfer restraint outer tube (5) wraps the buckling-restrained sleeve (54), and the spare force-transfer restraint outer tube (5) is formed by welding 4 steel plates. The length of the buckling-restrained sleeve (54) is less than the length of the spare force-transfer restraint outer tube (5), and guide groove stiffeners (541) are provided in four orthogonal directions on the inner surfaces at both ends of the spare force-transfer restraint outer tube (5), and the formed guide grooves are used to limit the out-of-plane instability of the end strengthening area (11) of the buckling-free energy dissipation core (1), and the guide groove stiffeners (541) and the reinforcing end head (52) are located at the same end. In this application mode, the bearing capacity and stiffness of the second compression bearing mechanism of the proposed multi-stage force-bearing buckling-restrained brace can be significantly reduced, and at the same time, the spare force-transfer restraint outer tube (5) can enter the yield energy dissipation state.

[0058] As shown in Figure 11As shown in the figure, the present invention is arranged diagonally within one span of a building, connecting to the apex node formed by a frame beam (8) and a frame column (9) at one end, and connecting to the bottom corner node formed by the frame beam (8) and the frame column (9) at the other end. To ensure continuous force transmission, the present invention needs to be continuously arranged from the first floor to the top floor in the building. Under the excitation of seismic action, if the inter-story deformation of the structure continuously increases, the force-displacement response of the present invention is as Figure 13 shown.

[0059] Taking Figure 9 the application mode shown as an example, Its force-bearing mechanism such as Figure 12 shown in -a.

[0060] First, when the structure is subjected to seismic action within the design expectation and the brace is in tension, the non-buckling energy dissipation core (1) will undergo tensile deformation, and the upper and lower connection ends (2, 3) and the strengthening end (52) have a tendency to move apart. Since the rigid tie rod (42) of the standby tie rod system (4) in this technical solution extends a certain distance outside the outer surfaces of the upper and lower connection ends (2, 3) and the strengthening end (52), and elastic components (43) are placed in the extended redundant length range; at this stage, the elastic components (43) can undergo significant elastic compression deformation. Therefore, the separation movement of the upper and lower connection ends (2, 3) and the strengthening end (52) is basically unobstructed, and the non-buckling energy dissipation core (1) has a free deformation space at this stage. The size of this free deformation space is Figure 12 x2 shown in -a, and due to the tensile bearing capacity generated by the compression deformation of the elastic components (43), part of it is transmitted to the upper and lower connection ends (2, 3) through the bolt fasteners (41), rigid tie rods (42), and standby force transmission constraint outer tubes (5), improving the tensile bearing capacity of the multi-stage force-bearing buckling restraint brace invented in the free deformation stage and making up for the pressure increase effect caused by the Poisson effect and friction of ordinary buckling restraint braces. This corresponds to Figure 13 the tensile performance of the brace before time t2 in.

[0061] Second, when the structure is subjected to a stronger seismic action, when the tensile deformation of the non-buckling energy dissipation core (1) exceeds the reserved value x2 (see Figure 12 -a), the elastic components (43) are completely compressed, and the stiffness of the elastic components (43) increases significantly. A second tensile load-bearing mechanism composed of the upper and lower connection ends (2, 3), the standby tie rod system (4), and the standby force transmission constraint outer tube (5) is formed, the tensile bearing capacity and stiffness of the brace are improved, the emergence of weak layers in the structure is inhibited, and the anti-collapse ability of the structure is enhanced. This corresponds to Figure 13 the tensile performance of the brace after time t2 in.

[0062] Taking Figure 9 the application mode shown as an example, its force-bearing mechanism is asFigure 12 as shown in -c.

[0063] First, when the structure bears the seismic action within the design expectation and the non-buckling energy dissipation core (1) is compressed when the support is under compression, the non-buckling energy dissipation core (1) will undergo compressive deformation, and the upper and lower connection ends (2, 3) and the strengthening end (52) have a tendency to move closer to each other. Since the thickness y of the elastic cushion block (6) in this technical solution (see Figure 12 -c) is less than the clearance value x3 between the upper and lower connection ends (2, 3) and the strengthening end (52) (see Figure 12 -b), the relative movement of the upper and lower connection ends (2, 3) and the strengthening end (52) at this stage is not blocked, and the non-buckling energy dissipation core (1) has a free deformation space. At this stage, the proposed multi-stage force-bearing buckling-restrained brace is no different from the ordinary buckling-restrained brace.

[0064] Second, when the structure bears a stronger seismic action, when the compressive deformation of the non-buckling energy dissipation core (1) exceeds the reserved value x1 (see Figure 12 -c), the elastic cushion block (6) begins to bear pressure, and a second compressive load-bearing mechanism composed of the upper and lower connection ends (2, 3), the elastic cushion block (6), and the spare force-transferring restraint outer tube (5) is formed. The compressive bearing capacity and stiffness of the brace are improved, the emergence of the weak layer of the structure is inhibited, and the anti-collapse ability of the structure is enhanced. This corresponds to Figure 13 the compressive performance of the brace after the moment t1 in. Since the elastic cushion block (6) has a certain deformation ability, the impact effect when the upper and lower connection ends (2, 3) contact the elastic cushion block (6) is alleviated, and the stiffness of the second compressive load-bearing mechanism is reduced to a certain extent, further balancing the stiffness difference with the second tensile load-bearing mechanism.

[0065] The embodiments given only illustrate the principles and effects of the present invention by way of example, rather than limiting the present invention. Due to the diversity of the non-buckling energy dissipation core (1) and the spare force-transferring restraint outer tube (5) of the buckling-restrained brace, as long as any one of the upper and lower connection ends (2, 3) is connected to the spare force-transferring restraint outer tube (5) through the spare tie rod system (4) and the elastic cushion block (6), and a free deformation space for the non-buckling energy dissipation core (1) is reserved in the connection ( Figure 12 x1 and x2 in), the structural measures for forming the second resistance system of the brace through the upper and lower connection ends (2, 3), the spare tie rod system (4), and the spare force-transferring restraint outer tube (5) fall within the protection scope of this patent.

Claims

1. A multi-stage force-bearing anti-collapse buckling-restrained brace, comprising a non-buckling energy-dissipating core (1), a spare force-transferring restraint outer tube (5), and a buckling-restraining filling material (7). The non-buckling energy-dissipating core (1) is placed inside the spare force-transferring restraint outer tube (5), and the buckling-restraining filling material (7) is provided inside the spare force-transferring restraint outer tube (5). It is characterized in that: It also includes an upper connection end (2), a lower connection end (3), a spare tie rod system (4), and an elastic cushion block (6); the upper and lower ends of the buckling-free energy dissipation core (1) are respectively welded to the upper connection end (2) and the lower connection end (3). The spare force transfer and restraint outer tube (5) includes a tube body (51) and at least one reinforcing end (52), and the spare tie rod system (4) includes a bolt fastener (41), a rigid tie rod (42), and an elastic component (43). One end of the spare tie rod system (4) is connected to the upper connection end (2) or the lower connection end (3), and the other end is connected to the reinforcing end (52). Moreover, the rigid tie rod (42) should protrude from the outer surface of the connected upper connection end (2) or lower connection end (3), and also protrude from the outer surface of the corresponding reinforcing end (52); the elastic component (43) is placed in the redundant length interval obtained by the rigid tie rod (42) protruding from the outer surface of the connected component. The spare force transfer and restraint outer tube (5) has at least one reinforcing end (52) at one end, and is connected to one of the upper connection end (2) and the lower connection end (3) through the spare tie rod system (4). And an elastic cushion block (6) is arranged in the connection gap, and the connection gap is larger than the height of the elastic cushion block (6). The elastic cushion block (6) is fixedly connected to one of the reinforcing end (52) or the corresponding upper connection end (2) and lower connection end (3).

2. The multi-stage force-bearing anti-collapse buckling-restrained brace according to claim 1, characterized in that, The reinforcing end (52) of the spare force transfer and restraint outer tube (5) is a square thick plate, and is connected to the tube body (51) by welding. And stiffening ribs (53) are welded on at least two opposite outer surfaces of the tube body (51). Round holes (521) are opened between the stiffening ribs (53) of the reinforcing end (52), and the rigid tie rod (42) passes through the round holes (521).

3. The multi-stage force-bearing anti-collapse buckling-restrained brace according to claim 1, characterized in that, One end of the spare force transfer and restraint outer tube (5) without a reinforcing end (52) is fixedly connected to any one of the upper connection end (2) and the lower connection end (3).

4. The multi-stage force-bearing anti-collapse buckling-restrained brace according to claim 1, characterized in that, The buckling-resistant filling material (7) fills the inside of the spare force transfer and restraint outer tube (5), and is in direct contact with the inner surface of the spare force transfer and restraint outer tube (5). The inner surface of the spare force transfer and restraint outer tube (5) is flat, and has the dual functions of providing restraint and bearing force.

5. The multi-stage force-bearing anti-collapse buckling-restrained brace according to claim 1, characterized in that, The buckling-resistant filling material (7) fills the inside of the buckling-resistant sleeve (54). The buckling-resistant filling material (7) is in direct contact with the inside of the buckling-resistant sleeve (54). The spare force transfer and restraint outer tube (5) wraps the buckling-resistant sleeve (54), and the two slide relative to each other. There is a micro-gap between the outer surface of the buckling-resistant sleeve (54) and the inner surface of the spare force transfer and restraint outer tube (5). Guide groove stiffening ribs (541) are arranged in four orthogonal directions on the inner surface of at least one end of the spare force transfer and restraint outer tube (5). The guide groove stiffening ribs (541) and the reinforcing end (52) are located at the same end; the spare force transfer and restraint outer tube (5) has the triple functions of providing restraint, bearing, and energy dissipation.

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