SMA enhanced self-resetting modular steel structure connecting joint

Abstract

The SMA reinforced self-resetting modular steel structure connecting joint comprises an upper steel column, a lower steel column and a joint module installed between an inner cavity of the upper steel column and an inner cavity of the lower steel column. The joint module comprises an upper joint assembly, a lower joint assembly, a prestress opposite-pulling assembly and an SMA bar. The prestress opposite-pulling assembly connects the upper joint assembly and the lower joint assembly in an opposite-pulling mode from the middle and provides prestress. The SMA bars are vertically arranged at intervals in the circumferential direction, the upper joint assembly and the lower joint assembly are connected, and reset power is provided. A middle energy consumption plate is arranged between the upper joint assembly and the lower joint assembly in a cushioned mode. Vibration energy can be quickly dissipated in the earthquake in a double-effect mode, double-effect self-recovery can be achieved after the earthquake, vibration deformation can be controlled in the node module, the situation that large-scale correction needs to be conducted after the earthquake is avoided, residual deformation of the structure is remarkably reduced, deformation is prevented from being diffused into a steel column structure, the steel structure can be better protected, and the service life of the steel column structure is prolonged. And the anti-seismic property and the long-term safety of the whole steel structure system are improved.

Description

Technical Field

[0001] This invention relates to the field of steel structure construction technology, specifically to an SMA-reinforced self-resetting modular steel structure connection node. Background Technology

[0002] In building structures, splicing nodes not only bear the effective transmission of bending moment, shear force and axial force between modular units, but also directly affect the mechanical performance and stability of the entire structural system. The construction form and mechanical performance of splicing nodes directly determine the reliability, stability and safety reserve of the structure.

[0003] Traditional splicing joints mostly employ rigid connections, such as welding or ordinary bolts. While these connections can effectively bear normal loads, under extreme conditions like strong earthquakes, traditional rigid joints rely on the plastic yielding of steel for energy dissipation. For example, plastic hinges are formed at beam or column ends to absorb seismic energy. However, this energy dissipation mechanism often results in irreversible residual deformation of the structure after a strong earthquake, preventing it from returning to its original state. This phenomenon necessitates large-scale post-earthquake structural repairs, and in severe cases, demolition and reconstruction.

[0004] To overcome the problem of residual deformation, self-setting structural systems have been gradually proposed and applied. However, existing self-setting nodes mostly rely on prestressed cable systems, fluid dampers, or specific metal materials or components to achieve energy absorption and self-setting functions. They are usually composed of multiple components, and the connection and fit between the components require high precision. This makes the entire structural system very complex and space-consuming. It often requires relatively complex installation and adjustment work on site. On the one hand, this leads to complicated and cumbersome on-site construction and installation, which is highly dependent on the technical level and experience of the construction personnel. On the other hand, due to the complex structure and a large number of exposed energy dissipation components, it often gives people a cluttered and messy visual impression, which affects the aesthetics of the building and does not meet the aesthetic requirements of architectural design, thus limiting the appearance design of the building.

[0005] Therefore, it is necessary to study a SMA-enhanced self-resetting modular steel structure connection node. Summary of the Invention

[0006] Therefore, the purpose of this invention is to provide an SMA-enhanced self-resetting modular steel structure connection node, which can effectively solve the problems of large residual deformation after earthquake, complex on-site construction, and unsightly appearance of existing steel column self-resetting nodes.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A SMA-enhanced self-resetting modular steel structure connection node includes an upper steel column, a lower steel column, and a node module installed between the inner cavities of the upper and lower steel columns; The node module includes an upper node assembly, a lower node assembly, a prestressed tension assembly, and SMA rods; The upper node assembly is fixed in the inner cavity of the upper steel column and extends downward out of the upper steel column, while the lower node assembly is fixed in the inner cavity of the lower steel column and extends upward out of the lower steel column. The prestressed tension assembly connects the upper node assembly and the lower node assembly from the middle and provides prestress; The SMA rods are arranged vertically at intervals along the circumference to connect the upper node assembly and the lower node assembly and provide reset power. An intermediate energy-dissipating plate is provided between the upper node component and the lower node component.

[0008] Furthermore, the upper node assembly includes an upper inner sleeve and an upper mating plate; The lower node assembly includes a lower inner sleeve and a lower mating plate; The bottom of the upper inner sleeve is fixedly connected to the upper mating plate, and the top of the lower inner sleeve is fixedly connected to the lower mating plate. The upper and lower mating plates are adapted to be mated together. The intermediate energy-consuming plate is disposed between the upper connecting plate and the lower connecting plate; Both the upper and lower connecting plates are fixedly connected with connecting collars, which are fixedly fitted into the upper or lower steel column.

[0009] Furthermore, the upper node component also includes an upper end plate; The upper end plate is fixedly connected to the top of the upper inner sleeve; The lower node assembly also includes a lower end plate, which is fixedly connected to the bottom of the lower inner sleeve; The upper and lower ends of the SMA rod are fixed to the upper end plate and the lower end plate, respectively.

[0010] Furthermore, the upper steel column, the lower steel column, and the connecting collar are provided with corresponding mounting holes, and the upper steel column and the lower steel column are fixedly connected to the corresponding connecting collar by single-sided bolts.

[0011] Furthermore, the diameters of the upper and lower connecting plates are larger than the inner diameters of the upper and outer steel columns, and the upper and lower connecting plates are provided with clearance holes for the SMA rods and prestressed tension tie assemblies to pass through.

[0012] Furthermore, the prestressed tension assembly includes tension members and tension seats; The upper end plate and the lower end plate are respectively fixed around the side walls of the upper inner sleeve and the lower inner sleeve; The upper end face of the upper inner sleeve and the lower end face of the lower inner sleeve are both fixed with pull seats; The tie rod is vertically inserted through the center, passing through the upper and lower inner sleeves and fixedly connected to the tie rod seat, so as to tie the upper node assembly and the lower node assembly together and provide prestress.

[0013] Furthermore, the pull member includes a high-strength screw and a disc spring assembly. Both ends of the high-strength screw pass through the pull seat and are threadedly connected to pull nuts. A disc spring assembly is sleeved between the pull nuts and the pull seat.

[0014] Furthermore, the tie rod includes a steel strand, both the upper and lower ends of which pass through the tie rod seat and are threaded with tie rod nuts.

[0015] Furthermore, the pull seat includes a limiting sleeve and a pull plate, wherein the limiting sleeve is sleeved in the upper inner sleeve or the lower inner sleeve; The top of the limiting sleeve is fixed with a pull plate, which is fixedly attached to the relatively far end face of the upper inner sleeve or the lower inner sleeve by a pull member; the pull plate is provided with a pull hole for the pull member to pass through.

[0016] The beneficial effects of the above technical solution are: (1) The upper node assembly and the lower node assembly of the present invention are respectively fixed in the inner cavity of the upper and lower steel columns. The prestressed tension assembly connects the upper node assembly and the lower node assembly from the middle. First, the upper node assembly and the lower node assembly can be connected, and the vibration is controlled at the connection position of the upper and lower node assemblies. On the one hand, with the intermediate energy dissipation plate between the upper node assembly and the lower node assembly, a small relative displacement is generated during the vibration process, and the vibration energy is continuously consumed by friction. At the same time, the SMA rod is stretched during the vibration process. The SMA material fully utilizes its superelastic properties, generates a large elastic deformation without yielding, and its stress-strain curve forms a full hysteresis loop, which consumes a large amount of seismic energy. The two work together to reduce the internal stress of the node at the epicenter, forming a dual energy dissipation effect and improving the durability of the node after multiple vibrations.

[0017] On the other hand, the main deformation can be concentrated on the tie rods and SMA rods, so that the upper and lower steel columns will not undergo significant deformation after the earthquake, avoiding irreversible residual deformation of the steel columns. The tie rods and SMA rods can be replaced in case of failure after the earthquake without repairing the steel columns, which can effectively reduce the difficulty and workload of repair.

[0018] Secondly, the prestressed tension assembly can provide longitudinally contracting prestress, which can resist longitudinal deformation during vibration. On the other hand, the prestress can be combined with the hyperelasticity of the SMA bar to form a strong self-resetting torque, which can overcome the frictional resistance inside the system, force the open node interface to close, and return the column to the initial vertical position, achieving zero residual deformation.

[0019] In summary, this invention, through the synergistic effect of SMA rods, prestressed tension assemblies, intermediate energy dissipation plates, and other components, can achieve rapid and effective dissipation of seismic energy during an earthquake, achieve effective self-recovery after an earthquake, and control seismic deformation within the node modules, avoiding the need for large-scale post-earthquake correction. It also significantly reduces residual deformation of the structure, prevents deformation from spreading to the steel column structure, better protects the steel structure, and improves the seismic performance and long-term safety of the overall steel structure system.

[0020] (2) The node module of the present invention adopts a modular design, which can prefabricate all key components (such as upper node components, lower node components, prestressed tie rods, and SMA rods) in the factory, realizing the separation of the node from the main steel column components. On site, the node module only needs to be installed between the inner cavities of the upper and lower steel columns, avoiding complex adjustment and connection work on site, making the node module installation process simpler and faster, greatly reducing the dependence on on-site technicians and improving construction efficiency.

[0021] (3) The node module of the present invention is integrated and installed between the inner cavity of the upper steel column and the lower steel column. All the main components are located in the inner cavity of the steel column and will not be exposed to the outside, which reduces the visual clutter of the structure, meets the requirements of modern architectural design for aesthetics, and ensures the cleanliness, simplicity and modernity of the building appearance. Attached Figure Description

[0022] Figure 1 This is a three-dimensional schematic diagram of the node module of the present invention; Figure 2 This is an exploded view of the node module; Figure 3 A 3D schematic diagram of a double-column connection node; Figure 4 This is an exploded view of a double-column connection node. Figure 5 A three-dimensional schematic diagram of a four-column connection node; Figure 6 An exploded view of the four-column connection nodes; Figure 7 This is a schematic diagram of the stress and deformation of the connection node.

[0023] Reference numerals: 1. Upper steel column; 2. Lower steel column; 3. Upper node assembly; 4. Lower node assembly; 5. Prestressed tie rod assembly; 6. SMA bar; 7. Intermediate energy dissipation plate; 8. Connecting collar; 301. Upper inner sleeve; 302. Upper end plate; 303. Upper connecting plate; 401. Lower inner sleeve; 402. Lower end plate; 403. Lower connecting plate; 501. Tie rod seat; 502. Tie rod component; 503. Tie rod nut; 504. End; 5011. Limiting sleeve; 5012. Tie rod plate; 5021. High-strength screw; 5022. Disc spring assembly; 801. Mounting hole. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Example 1: This example aims to provide an SMA-reinforced self-resetting modular steel structure connection node, mainly used for column-to-column connection nodes, such as... Figure 3-6 It can be applied to two-column or four-column steel structures, and addresses the problems of large residual deformation after earthquakes, complex on-site construction, and unsightly appearance associated with existing self-resetting steel column nodes.

[0025] A type of SMA-reinforced self-resetting modular steel structure connection node, such as Figure 3-6 The system includes an upper steel column 1, a lower steel column 2, and a node module. Both upper steel column 1 and lower steel column 2 are square steel columns of the same specifications, with a vertically connected rectangular cavity inside. In this embodiment, the node module is installed as an independent prefabricated module between the cavities of upper steel column 1 and lower steel column 2. On-site installation only requires placing the node module between the cavities of the upper and lower steel columns, avoiding complex on-site adjustments and connections, improving construction efficiency. Furthermore, since the main components are all located within the cavities of the steel columns and are not exposed to the outside, the visual clutter of the structure is reduced, ensuring a clean and simple building appearance.

[0026] A gap is maintained between the upper steel column 1 and the lower steel column 2 to avoid direct contact, so that the main node module bears and dissipates the vibration deformation. The force mechanism is clarified, so that the upper and lower steel columns will not undergo significant deformation after the earthquake, and plastic damage to the steel columns is avoided.

[0027] like Figure 1 and Figure 2 The node module includes an upper node assembly 3, a lower node assembly 4, a prestressed tension tie assembly 5, and an SMA bar 6. The upper node assembly 3 is fixed in the inner cavity of the upper steel column 1 and extends downward out of the upper steel column 1. The lower node assembly 4 is fixed in the inner cavity of the lower steel column 2 and extends upward out of the lower steel column 2. The extended parts of the upper and lower node assemblies are used for mutual docking.

[0028] The upper node assembly 3 includes an upper inner sleeve 301 and an upper end plate 302, and the lower node assembly 4 includes a lower inner sleeve 401 and a lower end plate 402. Both the upper and lower inner sleeves are hollow square steel tubes with a cross-sectional dimension smaller than that of the upper and lower steel columns. The bottom of the upper inner sleeve 301 is fixedly connected to the upper steel column 1, and the top of the lower inner sleeve 401 is fixedly connected to the lower steel column 2.

[0029] Specifically, an upper end plate 303 is welded and fixedly connected to the bottom of the upper inner sleeve 301, and a lower mating plate 403 is welded and fixedly connected to the bottom of the lower inner sleeve 401. The upper end plate 303 and the lower mating plate 403 are square plates of compatible size. A connecting collar 8 is welded and fixedly connected to the upper surface of the upper end plate 303 and the lower surface of the lower mating plate 403. The connecting collar 8 maintains a gap with the upper and lower inner sleeves. The connecting collar 8 is a square collar and is fixedly fitted in the upper steel column 1 or the lower steel column 2. The upper steel column 1, the lower steel column 2 and the connecting collar 8 have corresponding arrayed mounting holes 801. The upper steel column 1 and the lower steel column 2 are fixedly connected to the corresponding connecting collar 8 by single-sided bolts.

[0030] Single-sided bolts are a special type of fastener used in industrial applications for connecting enclosed steel pipe structures. They enable single-sided installation and tightening without requiring entry into the steel pipe, significantly reducing welding work and simplifying the construction process.

[0031] In this embodiment, a connecting collar 8 is fixed on the upper and lower connecting plates 403 as a transition interface, and with the help of a single-sided bolt, the node can be prefabricated in the factory as an independent module. On-site, only tightening the bolts from the outside is required to complete the connection of the upper and lower steel columns, completely eliminating on-site welding and realizing fully prefabricated construction. In addition, the upper end plate 303 and the lower connecting plate 403 are used for the docking of the upper and lower node components. This is the main location where vibration deformation of the docking template occurs. Fixing the connecting collar 8 to the upper and lower connecting plates 403 to fix it to the upper and lower steel columns allows the connection point to be closer to the location of vibration deformation, effectively reducing the additional torque at the node, reducing unnecessary stress accumulation, and thus optimizing the stress situation of the entire structure.

[0032] The top of the upper inner sleeve 301 is fixed with an upper end plate 302, and the bottom of the lower inner sleeve 401 is welded and fixed with a lower end plate 402. The upper end plate 302 and the lower end plate 402 are mainly used for fixing the tie assembly and the SMA rod 6.

[0033] The prestressed tensioning assembly 5 vertically connects the upper node assembly 3 and the lower node assembly 4 from the geometric center of the node module and provides prestress. Specifically, in this embodiment, the prestressed tensioning assembly 5 includes a tensioning member 502 and a tensioning seat 501; the upper end plate 302 and the lower end plate 402 are respectively fixed around the side walls of the upper inner sleeve 301 and the lower inner sleeve 401 to leave the top opening of the upper inner sleeve 301 and the bottom opening of the lower inner sleeve 401. The tensioning seat 501 is fixed on the upper end face of the upper inner sleeve 301 and the lower end face of the lower inner sleeve 401; the tensioning seat 501 includes a limiting sleeve 5011 and a tensioning plate 5012, and the limiting sleeve 5011 is sleeved in the upper inner sleeve 301 or the lower inner sleeve 401. The top of the limiting sleeve 5011 is integrally formed with a tie plate 5012. The tie plate 5012 is fixedly attached to the relatively distant end face of the upper inner sleeve 301 or the lower inner sleeve 401 by the tie member 502. Together with the limiting sleeve 5011, it closes the opening of the upper and lower inner sleeves and has a compact structure, which can ensure the effective transmission of the prestress of the tie. The tie plate 5012 has a rectangular hole and an end 504 is embedded therein. The end 504 has a tie hole for the tie member 502 to pass through.

[0034] The tie member 502 is vertically inserted through the center, passing through the upper inner sleeve 301 and the lower inner sleeve 401, and is fixedly connected to the tie seat 501 to tie the upper node assembly 3 and the lower node assembly 4 and provide prestress. In this embodiment, the tie rod 502 includes a high-strength screw 5021 and a disc spring assembly 5022. Both the upper and lower ends of the high-strength screw 5021 pass through the tie rod seat 501 and are threaded with tie nuts 503. The high-strength screw 5021 runs through the entire upper and lower node assembly, providing extremely high axial tensile stiffness. The disc spring assembly 5022 is connected in series in the anchoring area at both ends of the screw (i.e., between the tie nuts 503 and the end 504). The disc spring assembly 5022 is pre-compressed, and its function is: (1) to provide elastic deformation stroke when the node opens, preventing the high-strength screw 5021 from affecting the swing of the SMA rod 6 or premature yielding during vibration; (2) if the screw produces a small amount of plastic deformation or loosening after the vibration, the rebound force of the disc spring is used for displacement compensation to ensure that the preload is not lost and to prevent the node from loosening. The high-strength screw 5021 provides initial axial stiffness, while the disc spring assembly 5022 provides crucial elastic deformation reserve and displacement compensation functions, ensuring the basic rigidity of the node.

[0035] like Figure 2SMA rods 6 are arranged vertically at intervals along the circumference, connecting the upper node assembly 3 and the lower node assembly 4 and providing reset power. The upper and lower ends of the SMA rods 6 are fixed to the upper end plate 302 and the lower end plate 402, respectively. Several SMA rods 6 are arranged symmetrically along the nodes. In this embodiment, three rods are arranged on each side of the symmetry, and the specific number can be adjusted according to the force calculation. The SMA rods 6 pass through the upper end plate 302, the upper end plate 303, the intermediate energy dissipation plate 7, the lower connecting plate 403, and the lower end plate 402 in sequence. The two ends of the SMA rods 6 are threaded. After passing through the external connecting plate, they are anchored and tensioned by special nuts, and a certain preload is applied. The SMA can be, but is not limited to, nickel-titanium (Ni-Ti) shape memory alloy material. It utilizes the "superelasticity" effect, which allows it to automatically return to its original shape after large deformation under tension and unloading, providing the main reset power.

[0036] Considering that the main location of vibration deformation is between the upper end plate 303 and the lower connecting plate 403, in this embodiment, an intermediate energy-dissipating plate 7 is provided between the upper end plate 303 and the lower connecting plate 403 to form end-face friction. The upper end plate 303 and the lower connecting plate 403 do not directly contact each other. The intermediate energy-dissipating plate 7 is preferably a brass plate or a friction composite material. By utilizing its stable friction coefficient with the steel, energy is dissipated through interface sliding during the node swaying process, while preventing the steel components from rusting and sticking.

[0037] The diameters of the upper end plate 303 and the lower connecting plate 403 are larger than the inner diameters of the upper steel column 1 and the outer steel column. The upper end plate 303 and the lower connecting plate 403 are located in the gap between the upper and lower steel columns. When the upper and lower connecting components are installed, the upper end plate 303 and the lower connecting plate 403 can achieve a rapid alignment effect.

[0038] The upper plate 303, the lower connecting plate 403, and the middle energy-consuming plate 7 are all provided with clearance holes for the SMA rod 6 and the tie assembly to pass through.

[0039] This embodiment is specifically divided into three working stages: (1) Normal use stage (elastic locking state); Under normal loads (dead load, live load) or minor earthquakes, the high axial stiffness of the high-strength 5021 screw, combined with the high preload of the disc spring, generates a huge normal contact pressure between the upper and lower inner sleeves and the intermediate friction plate. At this time, the frictional torque generated at the joint contact surface is greater than the bending moment generated by the external load, and the joint exhibits a rigid connection with no relative rotation, ensuring the normal stiffness and stability of the structure.

[0040] (2) Seismic action stage (swaying and energy dissipation state) When encountering a moderate or major earthquake, the structure bears a huge horizontal load. When the overturning moment generated by the horizontal seismic action overcomes the initial bending restraint moment formed by the preload of SMA rods 6 and high-strength bolts 5021, such as... Figure 7 When the end plate on the tension side of the node separates from the energy dissipation plate, an opening phenomenon occurs. The compression side continues to contact and acts as a fulcrum for rotation, causing the node to begin relative rotation (swinging). As the opening widens, the SMA rod 6 on the tension side is stretched. The SMA material fully utilizes its hyperelastic properties, producing a large amount of elastic deformation without yielding. Its stress-strain curve forms a full hysteresis loop, consuming a large amount of seismic energy. Simultaneously, during the swinging process, slight relative misalignment occurs between the inner sleeve, the square connector, and the energy dissipation plate. The interfacial friction further provides damping, dissipating energy and creating a dual energy dissipation effect.

[0041] During this process, the disc spring assembly 5022 on the tension side is further compressed (or released, depending on the specific construction), allowing the screw to move axially with the node deformation, thus preventing the screw from directly entering plastic yield.

[0042] (3) Post-earthquake recovery stage (self-reset state) After the seismic action subsides, the joint is forcibly closed by the superelastic restoring force of the SMA and the elastic rebound force of the disc spring assembly 5022. Specifically, even if the screw undergoes slight plastic elongation during a major earthquake, the series-connected disc spring assembly 5022 will absorb this elongation through rebound, keeping the screw always under tension and ensuring that the joint does not loosen after the earthquake and has zero residual deformation. The restoring force of the SMA plus the elastic rebound force of the disc spring assembly 5022 together constitute a powerful self-resetting torque. This torque can overcome the internal frictional resistance of the system, forcibly closing the opened joint interface, returning the column to its initial vertical position, and achieving zero residual deformation.

[0043] During this process, the prestressed tension assembly 5 and the SMA bar 6 form a parallel reset mechanism. On the one hand, the shape memory alloy material can spontaneously recover its initial shape after stress relief by utilizing its superelastic properties, providing the core reset power under large deformation. On the other hand, with the help of the elastic energy storage and displacement compensation characteristics of the high-strength screw 5021 and the series disc spring group 5022, the prestress loss that may occur after the earthquake can be effectively compensated, ensuring that the joint does not loosen for a long time, thus forming a dual reset effect.

[0044] Example 2 is basically the same as Example 1, except that the tie member 502 uses steel strand instead of high-strength screw 5021 and disc spring assembly 5022.

[0045] The tie member 502 includes a steel strand. Both ends of the steel strand pass through the tie seat 501 and are threadedly connected to the tie nut 503. The steel strand is prestressed by the steel strand anchor and fixed by the tie nut 503.

[0046] The function of the steel strand is basically the same as that of the high-strength screw 5021 combined with the disc spring assembly 5022. It mainly connects the upper and lower node components and provides basic rigidity. It can also work together with the SMA rod 6 after the earthquake through its own elastic restoring force to form a double-effect reset function, ensuring that the structure can automatically return to its normal position after a major earthquake.

Claims

1. An SMA-reinforced self-centering modular steel structure connection node, characterized by: The node module is arranged between the inner cavities of the upper steel column (1) and the lower steel column (2). The node module comprises an upper node assembly (3), a lower node assembly (4), a prestressed tensioning assembly (5) and an SMA rod (6). The upper node assembly (3) is fixed in the inner cavity of the upper steel column (1) and extends downward out of the upper steel column (1), and the lower node assembly (4) is fixed in the inner cavity of the lower steel column (2) and extends upward out of the lower steel column (2). The prestressed tensioning assembly (5) is arranged to connect the upper node assembly (3) and the lower node assembly (4) and provide prestress. The SMA rod (6) is arranged vertically and spaced apart circumferentially to connect the upper node assembly (3) and the lower node assembly (4) and provide reset power. An intermediate energy dissipation plate (7) is arranged between the upper node assembly (3) and the lower node assembly (4).

2. The SMA-augmented self-centering modular steel structure connection node of claim 1, wherein: The upper node assembly (3) comprises an upper inner sleeve (301) and an upper butt plate (303). The lower node assembly (4) comprises a lower inner sleeve (401) and a lower butt plate (403). The bottom of the upper inner sleeve (301) is fixedly connected with the upper butt plate (303), and the top of the lower inner sleeve (401) is fixedly connected with the lower butt plate (403). The intermediate energy dissipation plate (7) is arranged between the upper butt plate (303) and the lower butt plate (403). The upper butt plate (303) and the lower butt plate (403) are fixedly connected with a connecting sleeve ring (8), and the connecting sleeve ring (8) is fixedly sleeved in the upper steel column (1) or the lower steel column (2).

3. The SMA-augmented self-centering modular steel structure connection node of claim 2, wherein: The upper node assembly (3) further comprises an upper end plate (302). The upper end plate (302) is fixedly connected to the top of the upper inner sleeve (301). The lower node assembly (4) further comprises a lower end plate (402), and the lower end plate (402) is fixedly connected to the bottom of the lower inner sleeve (401). The upper and lower ends of the SMA rod (6) are fixed to the upper end plate (302) and the lower end plate (402), respectively.

4. The SMA-augmented self-centering modular steel structure connection node of claim 3, wherein: The upper steel column (1), the lower steel column (2) and the connecting sleeve ring (8) are provided with corresponding mounting holes (801), and the upper steel column (1) and the lower steel column (2) are fixedly connected with the corresponding connecting sleeve ring (8) through single-side bolts.

5. The SMA-augmented self-centering modular steel structure connection node of claim 4, wherein: The diameters of the upper butt plate (303) and the lower butt plate (403) are greater than the inner diameters of the upper steel column (1) and the lower steel column (2), and the upper butt plate (303) and the lower butt plate (403) are provided with avoiding holes for the SMA rod (6) and the prestressed tensioning assembly (5) to pass through.

6. A SMA-augmented self-centering modular steel structure connection node according to any one of claims 3-5, characterized in that: The prestressed tensioning assembly (5) comprises a tensioning piece (502) and a tensioning seat (501). The upper end plate (302) and the lower end plate (402) are respectively fixedly arranged around the side walls of the upper inner sleeve (301) and the lower inner sleeve (401). The upper end surface of the upper inner sleeve (301) and the lower end surface of the lower inner sleeve (401) are fixedly provided with the tensioning seat (501). The pair of pullers (502) vertically pass through the upper inner sleeve (301) and the lower inner sleeve (401) from the center and are fixedly connected with the pair of pull seats (501), so as to pull and connect the upper node assembly (3) and the lower node assembly (4) and provide prestress.

7. The SMA-augmented self-centering modular steel structure connection node of claim 6, wherein: The pair of pullers (502) include high-strength screw rods (5021) and disc spring groups (5022), the upper and lower ends of the high-strength screw rods (5021) pass through the pair of pull seats (501) and are threadedly connected with pair of pull nuts (503), and the disc spring groups (5022) are sleeved between the pair of pull nuts (503) and the pair of pull seats (501).

8. The SMA-augmented self-centering modular steel structure connection node of claim 6, wherein: The pair of pullers (502) include steel strands, the upper and lower ends of the steel strands pass through the pair of pull seats (501) and are threadedly connected with pair of pull nuts (503).

9. The SMA-augmented self-centering modular steel structure connection node of claim 6, wherein: The pair of pull seats (501) include limiting sleeves (5011) and pair of pull plates (5012), the limiting sleeves (5011) are sleeved in the upper inner sleeve (301) or the lower inner sleeve (401); The top of the limiting sleeve (5011) is fixedly connected with the pair of pull plates (5012), the pair of pull plates (5012) are fixedly attached to the opposite end faces of the upper inner sleeve (301) or the lower inner sleeve (401) through the pair of pullers (502), and the pair of pull plates (5012) are provided with pair of pull holes for the pair of pullers (502) to pass through.

Images