A ductility enhanced steel frame structure

Abstract

This invention discloses a steel frame structure with enhanced toughness, relating to the field of building technology. It includes steel beams and steel columns; the junction of the steel beams and columns is a beam-column node; the beam-column node includes connecting components and anchoring components; both ends of the pre-tensioned energy-dissipating member are connected to high-strength tie bars via a first limiting component, and the other end of the high-strength tie bar is connected to a second limiting component; a first fixing component is vertically fixed to the inner side of the steel beam flange, and a second fixing component is vertically fixed to the outer side of the steel beam flange; reinforcing plates are provided on the first and second fixing components near the steel column; the high-strength tie bar passes through the first, second, and third fixing components. Based on the design concept of pre-tensioning and relaxation, the pre-tensioned energy-dissipating member with a slightly smaller bearing capacity is pre-tensioned, allowing it to dissipate energy before the main structural components; the high-strength tie bar, which is in a relaxed state for a certain period, serves as the last line of defense for the beam-column node. These two components work together with traditional steel frame structures to significantly improve structural toughness.

Description

Technical Field

[0001] This invention relates to the field of building technology, and more specifically to a steel frame structure with enhanced toughness. Background Technology

[0002] With the continuous and positive development of the social economy, people's demands for building quality are increasing daily, thus promoting the application and popularization of steel structures. Steel structures are naturally prefabricated buildings, possessing advantages such as lightweight and high strength, good seismic performance, and recyclability, fully aligning with the current green and low-carbon development concept. At the same time, steel structures have excellent machinability and diverse node connection methods, making them suitable for industrialized production and prefabricated construction. Due to its wide applicability, steel frame structures have become the most widely used type of steel structure in engineering applications. They can be used alone in multi-story and high-rise buildings, or in conjunction with shear walls, core tubes, etc., to form various high-performance structural systems.

[0003] For steel frame structures, the performance of the connection nodes directly determines the overall structural performance. In the Northridge and Hanshin earthquakes, accident investigators found that brittle fracture at the nodes led to premature failure of the steel frame structures, failing to fully utilize the excellent seismic resistance of steel. Based on this, researchers proposed toughening enhancement methods such as weakened nodes, strengthened nodes, and semi-rigid nodes. Weakening nodes involve setting a weakening section of a certain length at the beam end, shifting the plastic zone of the node outward to the weakened area, thus protecting the beam-column joint area. However, setting a weakening section reduces the load-bearing capacity of the node; therefore, strengthened nodes were proposed. This involves setting a reinforcing cap plate or increasing the flange width in the beam-column joint area, which also achieves the outward shift of the plastic zone. This method does not reduce the node's load-bearing capacity; on the contrary, it increases it. Semi-rigid nodes reduce the stiffness of the node connection, increasing the node's rotational deformation capacity and preventing sudden brittle fracture failure.

[0004] Besides earthquakes, when steel frame structures are subjected to unexpected loads such as car impacts, explosions, and fires, the frame columns often fail suddenly, triggering a chain reaction and ultimately leading to catastrophic partial or total collapse. During the collapse, the steel beams above the failed column undergo significant downward deflection, creating a catenary effect to resist unbalanced loads. Under this large deformation state, the beam-column joint above the failed column will bear enormous horizontal tensile and bending moments. Current defensive measures mainly involve adding additional tension members to fully utilize the catenary effect of the steel beams. The additional tension members do not affect the joint's stress before the joint fractures; after the joint fractures, the additional tension members provide secondary resistance to the joint. When the additional tension members reach their ultimate resistance, the joint ultimately fails.

[0005] Based on this, existing methods for enhancing the toughness of steel frame structures have the following main drawbacks:

[0006] (a) Under the small deformation state in the early stage of stress, especially when semi-rigid nodes are used, the existing steel frame structure basically does not consume energy, which is not conducive to the seismic resistance of the structure. Under the large deformation state, the failure of the additional tension members determines the ultimate resistance of the node, and the potential bearing capacity of the steel beam is not fully activated. A more reasonable failure mode should be that the additional tension members do not fail, but the steel beam undergoes secondary fracture in the region far from the node.

[0007] (b) Plastic deformation is concentrated in localized areas, and the amount of material available for energy dissipation is very limited, thus limiting the improvement in structural toughness. Except for the ends where the steel beams enter a plastic state, most of the remaining locations remain in an elastic state, resulting in low material utilization and the steel beams' performance not being fully realized. Furthermore, steel columns exhibit similar problems, with plastic deformation concentrated at the column base, while most other locations remain in an elastic state. Summary of the Invention

[0008] (a) Technical problems to be solved

[0009] In view of the shortcomings of the prior art, the present invention provides a steel frame structure with enhanced toughness, which solves at least one of the technical problems mentioned in the background art.

[0010] (II) Technical Solution

[0011] The technical solution adopted in this invention is:

[0012] A toughened steel frame structure, comprising steel beams and steel columns; the junction of the steel beams and steel columns is a beam-column joint;

[0013] The beam-column joint includes a connection component and an anchoring component;

[0014] The connecting assembly includes a pre-tensioned energy-dissipating component, a first limiting component, a high-strength tie bar, and a second limiting component. Both ends of the pre-tensioned energy-dissipating component are connected to the high-strength tie bar through the first limiting component, and the connection is made by thread. The other end of the high-strength tie bar is connected to the second limiting component, and the connection is made by welding or thread.

[0015] The anchoring assembly includes a first fixing member, a second fixing member, a third fixing member, and a reinforcing plate. The first fixing member is vertically fixed to the inner side of the steel beam flange, and the second fixing member is vertically fixed to the outer side of the steel beam flange. A reinforcing plate is provided on the side of the first and second fixing members near the steel column.

[0016] The high-strength tie bar penetrates the first fastener, the second fastener, and the third fastener.

[0017] Preferably, the pretensioning energy dissipation component and the first limiting component are both located inside the steel column and the anchoring assembly, and there is a gap between the first limiting component and the steel column flange and the anchoring assembly. The second limiting component is located outside the anchoring assembly, and the second limiting component is in close contact with the anchoring assembly.

[0018] Preferably, the steel column flange, the first fixing member, the second fixing member, and the third fixing member are all provided with through holes at the positions where they intersect with the high-strength tie bars, and the steel beam web and the steel column web are provided with through holes at the positions where they intersect with the pre-tensioned energy dissipation member. The size of the through holes is smaller than the cross-sectional size of the first limiting member and the second limiting member.

[0019] Preferably, the threads at both ends of the pretensioned energy dissipation component are in opposite directions, and a clamp for applying preload is provided in the middle of the pretensioned energy dissipation component.

[0020] Preferably, the axial bearing capacity of the high-strength tie bar is greater than that of the steel beam, while the axial bearing capacity of the pre-tensioned energy dissipation component is less than that of the steel beam.

[0021] Preferably, the third fixing member is disposed on the inner side of the steel column flange and located on the outer side of the steel beam flange, and the third fixing member is connected to the steel beam and steel column through a connecting plate.

[0022] Preferably, when the beam-column joint is located at the edge or corner of the toughened steel frame structure, one end of the pre-tensioned energy dissipation member is located on the outside of the toughened steel frame structure and is anchored to the outer side of the steel column flange or the third fixing member by the second limiting member.

[0023] Preferably, the connection between the steel column and the foundation is a column base node, which also includes a connection component and an anchoring component;

[0024] The connecting assembly includes a pre-tensioned energy-dissipating component and a second limiting component. The second limiting component is disposed at both ends of the pre-tensioned energy-dissipating component, and the connection position adopts a threaded connection.

[0025] The anchoring assembly includes a first fixing member, which is vertically fixed to the inner side of the steel column flange, and a reinforcing plate is provided on the first fixing member near the foundation side.

[0026] Preferably, the pre-tensioned energy-dissipating component passes through the pre-set through hole on the column base plate and the first fixing component, and the through hole size should be smaller than the cross-sectional size of the second limiting component.

[0027] (III) Beneficial Effects

[0028] This invention provides a steel frame structure with enhanced toughness, which has the following advantages compared with the prior art:

[0029] The design balances structural toughness enhancement under both small and large deformation conditions, creating multiple lines of defense at connection nodes and achieving a more reasonable failure process. Under small deformation conditions, the structure begins to dissipate energy, while under large deformation conditions, the ultimate resistance of the beam-column joints is determined by the steel beams.

[0030] The plastic deformation zone expands, and material utilization improves. For beam-column joints, plastic deformation occurs at various locations, including the additional members (pre-tensioned energy-dissipating components), the steel beams in the joint area, and the steel beams far from the joint area. For column base joints, the additional members enter the plastic energy-dissipating state earlier.

[0031] Based on the design concept of pre-tensioning and relaxation, a steel frame structure with enhanced toughness is proposed. Pre-tensioned energy-dissipating components with slightly lower load-bearing capacity are pre-tensioned, allowing them to dissipate energy before the main structural members. High-strength tie bars, which remain in a relaxed state for a certain period, serve as the final line of defense at beam-column joints. These two components work in conjunction with traditional steel frame structures to significantly improve structural toughness.

[0032] A relatively simple structural design enhances structural toughness. The connection between pre-tensioned energy-dissipating components and high-strength tie bars is simple and direct, with a clear working principle between components. A phased working mode design is adopted, with clear transition processes between stages, making full use of material properties. Utilizing column flanges or column base plates as anchor points fully leverages the existing structural features. Attached Figure Description

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0034] Figure 1 This is a schematic diagram of a steel frame structure with enhanced toughness according to an embodiment of the present invention;

[0035] Figure 2 for Figure 1 Structural schematic diagram of the beam-column joint at point A;

[0036] Figure 3 for Figure 1 A schematic diagram of the connecting component at point A in the middle;

[0037] Figure 4 for Figure 1 Layout diagram of internal connection components of the steel beam at point A;

[0038] Figure 5 for Figure 1 Schematic diagram of the anchoring component at point A;

[0039] Figure 6 for Figure 1 A schematic diagram of the combination of the connecting component and the anchoring component at point A in the middle;

[0040] Figure 7 for Figure 1Structural schematic diagram of the beam-column joint at point B;

[0041] Figure 8 for Figure 1 Structural schematic diagram of the beam-column joint at point C;

[0042] Figure 9 for Figure 1 Structural schematic diagram of the beam-column joint at point D;

[0043] Figure 10 for Figure 1 Schematic diagram of the column base node at point E;

[0044] Figure 11 for Figure 1 A schematic diagram of the connecting component at point E in the middle;

[0045] Figure 12 for Figure 1 Schematic diagram of the anchoring component at point E;

[0046] Figure 13 for Figure 1 A schematic diagram of the combination of the connecting component and the anchoring component at point E in the middle;

[0047] Among them, the steel frame structure with enhanced toughness consists of 1, steel beams, 2, steel columns, 3, pre-tensioned energy-dissipating components, 4, first limiting components, 5, high-strength tie bars, 6, second limiting components, 7, first fixing components, 8, second fixing components, 9, third fixing components, 10, reinforcing plates, and 11, connecting plates. Specific implementation methods

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] To better understand the above technical solutions, the following will provide a detailed description of the technical solutions in conjunction with the accompanying drawings and specific implementation methods, such as... Figures 1-13 As shown.

[0050] The steel frame structure 1 with enhanced toughness provided in the embodiments of the present invention, such as Figure 1 As shown, the toughened steel frame structure 1 includes steel beams 2 and steel columns 3; the junction of the steel beams 2 and steel columns 3 is a beam-column node;

[0051] in Figure 2 This is a structural diagram of the beam-column joint at point A. The beam-column joint is equipped with connecting components and anchoring components. The specific structure is as follows: Figures 3-6As shown:

[0052] The connecting assembly includes a pre-tensioned energy-dissipating component 4, a first limiting component 5, a high-strength tie bar 6, and a second limiting component 7. Both ends of the pre-tensioned energy-dissipating component 4 are connected to the high-strength tie bar 6 via threaded connections, with the first limiting component 5 positioned at the connection points. The other end of the high-strength tie bar 6 is connected to the second limiting component 7 via welding or threaded connections.

[0053] The pretensioning energy dissipation component 4 and the first limiting component 5 are both located inside the steel column 3, and there is a gap between the first limiting component 5 and the flange of the steel column 3 and the anchoring assembly. The second limiting component 7 is located outside the anchoring assembly, and the second limiting component 7 is in close contact with the anchoring assembly.

[0054] The threads at both ends of the pretensioning energy dissipation component 4 are in opposite directions, and a locking jaw is provided in the middle to facilitate clamping the pretensioning energy dissipation component 4 with a wrench. Then, the pretensioning energy dissipation component 4 is tightened with a wrench to enable it to bear force in advance. The axial bearing capacity of the high-strength tie bar 6 is greater than that of the steel beam 2, while the axial bearing capacity of the pretensioning energy dissipation component 4 is less than that of the steel beam 2.

[0055] Furthermore, the anchoring assembly includes a first fixing member 8, a second fixing member 9, and a third fixing member 10, and also includes a reinforcing plate 11 and a connecting plate 12; wherein, the high-strength tie bar 6 passes through the first fixing member 8, the second fixing member 9, and the third fixing member 10.

[0056] The first fastener 8 is located on the inner side of the flange of the steel beam 2, and the second fastener 9 is located on the outer side of the flange of the steel beam 2. A reinforcing plate 11 is provided on the side of the first fastener 8 and the second fastener 9 near the steel column 3.

[0057] The third fastener 10 is located on the inner side of the flange of the steel column 3 and on the outer side of the flange of the steel beam 2. The third fastener 10 is connected to the steel beam 2 and the steel column 3 through the connecting plate 12.

[0058] The flange of steel column 3, the first fixing member 8, the second fixing member 9, and the third fixing member 10 all have through holes at their intersections with the high-strength tie bar 6. The web of steel beam 2 and the web of steel column 3 also have through holes at their intersections with the pre-tensioned energy-dissipating member 4. The size of the through holes should be smaller than the cross-sectional dimensions of the first limiting member 5 and the second limiting member 7.

[0059] Figures 7-9 The diagram shows the structure of beam-column joints at other locations. When the beam-column joints are located at the edge or corner of the toughened steel frame structure, one end of the pre-tensioned energy dissipation member 4 is set on the outside of the toughened steel frame structure and is anchored to the flange of the steel column 3 or the outside of the third fixing member 10 by the second limiting member 7.

[0060] Specific Figure 7 for Figure 1Structural schematic diagram of the beam-column joint at point B; Figure 8 for Figure 1 Structural schematic diagram of the beam-column joint at point C; Figure 9 for Figure 1 The structural diagram of the beam-column joint at point D is shown. The only difference between the beam-column joints mentioned above is the location of the beam-column intersection.

[0061] The structure and stress process of the beam-column joint mentioned above are similar to those of the beam-column joint at point A. The difference is that one end of the pre-tensioned energy dissipation component 4 is located outside the toughened steel frame structure and is anchored to the flange of the steel column 3 or the outside of the third fixing component 10 by the second limiting component 7.

[0062] Furthermore, Figure 10 This is a structural diagram of the column base node at point E. The column base also has connecting components and anchoring components, as shown in the diagram. Figures 11-13 The connection between the steel column 3 and the foundation is a column base node, which also includes a connecting component and an anchoring component; the connecting component includes a pre-tensioned energy dissipation component 4 and a second limiting component 7, the second limiting component 7 is disposed at both ends of the pre-tensioned energy dissipation component 4, and the connection position adopts a threaded connection;

[0063] The anchoring assembly includes a first fixing member 8, which is vertically fixed to the inner side of the flange of the steel column 3. A reinforcing plate 11 is provided on the first fixing member 8 near the foundation. The pre-tensioned energy dissipation member 4 passes through a pre-set through hole in the column base plate and the first fixing member 8. The size of the through hole should be smaller than the cross-sectional size of the second limiting member 7.

[0064] The deformation of the bottom column base node is relatively small, so no high-strength tie bar 6 is provided, only a pre-tensioned energy dissipation component 4 is provided. The pre-tensioned energy dissipation component 4 passes through the pre-set through hole on the column base plate and the first fixing component 8. The size of the through hole should be smaller than the cross-sectional size of the second limiting component 7.

[0065] During operation, the aforementioned toughened steel frame structure, due to the relatively small cross-sectional size of the pre-tensioned energy-dissipating component 4, is subjected to a certain preload to ensure that it enters a plastic energy-dissipating state in the initial stage of stress, forming the first line of defense for the structure. Because its load-bearing capacity is relatively small, it fails first under tensile stress.

[0066] When it breaks, due to the gap between the first limiting member 5 and the flange of the steel column 3 and the third fixing member 10, the high-strength tie bar 6 will be in a relaxed state without stress for a certain period of time. At this time, the flange of the steel beam 2 on the outside of the flange of the steel column 3 will serve as the second line of defense of the structure and continue to resist the action of external loads.

[0067] When the flange of steel beam 2 fractures, the first limiting member 5 moves under tension to fit tightly against the flange of steel column 3 and the third fixing member 10. The high-strength tie bar 6 then begins to function as a tie, forming the third line of defense for the structure. The high-strength tie bar 6 has a larger cross-sectional dimension and higher material strength, ensuring its load-bearing capacity is higher than that of the flange of steel beam 2. Therefore, as the external load increases, a second fracture will occur on the flange of steel beam 2 outside the first and second fixing members 8, ultimately leading to the failure of the entire joint area.

[0068] In addition, the structure and stress process of the side span beam-column joint are similar to those of the middle joint, and there are also three lines of defense; the deformation of the bottom column foot joint is relatively small, and only the pre-tensioned energy dissipation component 4 is set to improve the toughness of the column foot, thus forming two lines of defense.

[0069] The embodiments of the present invention have the following beneficial effects:

[0070] The design balances structural toughness enhancement under both small and large deformation conditions, creating multiple lines of defense at connection nodes and achieving a more reasonable failure process. Under small deformation conditions, the structure begins to dissipate energy, while under large deformation conditions, the ultimate resistance of the beam-column joints is determined by the steel beams.

[0071] The plastic deformation zone expands, and material utilization improves. For beam-column joints, plastic deformation occurs at various locations, including the additional members (pre-tensioned energy-dissipating components), the steel beams in the joint area, and the steel beams far from the joint area. For column base joints, the additional members enter the plastic energy-dissipating state earlier.

[0072] Based on the design concept of pre-tensioning and relaxation, a steel frame structure with enhanced toughness is proposed. Pre-tensioned energy-dissipating components with slightly lower load-bearing capacity are pre-tensioned, allowing them to dissipate energy before the main structural members. High-strength tie bars, which remain in a relaxed state for a certain period, serve as the final line of defense at beam-column joints. These two components work synergistically with traditional toughness-enhanced steel frame structures to significantly improve structural toughness.

[0073] A relatively simple structural design enhances structural toughness. The connection between pre-tensioned energy-dissipating components and high-strength tie bars is simple and direct, with a clear working principle between components. A phased working mode design is adopted, with clear transition processes between stages, making full use of material properties. Utilizing column flanges or column base plates as anchor points fully leverages the existing structural features.

[0074] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0075] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ductility enhanced steel frame structure, characterized by, The steel frame structure with enhanced toughness comprises steel beams (2) and steel columns (3); the steel beams (2) and steel columns (3) are connected at beam-column joints; The beam-column joint comprises a connecting assembly and an anchoring assembly; The connecting assembly comprises a pre-tensioned energy dissipation member (4), a first limiting member (5), a high-strength tie (6) and a second limiting member (7); the two ends of the pre-tensioned energy dissipation member (4) are connected with the high-strength tie (6) through the first limiting member (5), the connecting position adopts threaded connection, the other end of the high-strength tie (6) is connected with the second limiting member (7), and the connecting position adopts welding or threaded connection; The anchoring assembly comprises a first fixing member (8), a second fixing member (9), a third fixing member (10) and a reinforcing plate (11); the first fixing member (8) is vertically fixed to the inner side of the flange of the steel beam (2), the second fixing member (9) is vertically fixed to the outer side of the flange of the steel beam (2), and the reinforcing plate (11) is arranged on the side of the first fixing member (8) and the second fixing member (9) close to the steel column (3); The high-strength tie (6) penetrates the first fixing member (8), the second fixing member (9) and the third fixing member (10); The pre-tensioned energy dissipation member (4) and the first limiting member (5) are located inside the steel column (3) and the anchoring assembly, and a gap is arranged between the first limiting member (5) and the flange of the steel column (3) and the anchoring assembly; the second limiting member (7) is located outside the anchoring assembly, and the second limiting member (7) is closely attached to the anchoring assembly; The flange of the steel column (3), the first fixing member (8), the second fixing member (9) and the third fixing member (10) are all provided with through holes at the positions penetrating the high-strength tie (6); the web of the steel beam (2) and the web of the steel column (3) are provided with through holes at the positions penetrating the pre-tensioned energy dissipation member (4); the size of the through holes is smaller than the cross-sectional size of the first limiting member (5) and the second limiting member (7); The third fixing member (10) is arranged on the inner side of the flange of the steel column (3) and on the outer side of the flange of the steel beam (2); the third fixing member (10) is connected with the steel beam (2) and the steel column (3) through a connecting plate (12); When the beam-column joint is located at the edge or corner of the steel frame structure with enhanced toughness, one end of the pre-tensioned energy dissipation member (4) is arranged on the outer side of the steel frame structure with enhanced toughness and is anchored to the flange of the steel column (3) or the outer side of the third fixing member (10) through the second limiting member (7); The connection between the steel column (3) and the foundation is a column base joint, and the column base joint also comprises a connecting assembly and an anchoring assembly; The connecting assembly comprises a pre-tensioned energy dissipation member (4) and a second limiting member (7); the second limiting member (7) is arranged at the two ends of the pre-tensioned energy dissipation member (4), and the connecting position adopts threaded connection; The anchoring assembly comprises a first fixing member (8); the first fixing member (8) is vertically fixed to the inner side of the flange of the steel column (3), and a reinforcing plate (11) is arranged on the side of the first fixing member (8) close to the foundation.

2. The ductility enhanced steel frame structure according to claim 1, wherein: The threaded directions of the two ends of the pre-tensioned energy dissipation member (4) are opposite, and a bayonet for applying pre-tightening force is arranged in the middle of the pre-tensioned energy dissipation member (4).

3. The ductility enhanced steel frame structure according to claim 1, wherein: The axial bearing capacity of the high-strength tie bar (6) is greater than that of the steel beam (2), and the axial bearing capacity of the pre-tensioned energy dissipation member (4) is less than that of the steel beam (2).

4. The ductility enhanced steel frame structure according to claim 1, wherein: The pre-tensioned energy dissipation member (4) penetrates the through hole pre-set on the first fixing member (8) and the column foot bottom plate, and the size of the through hole should be smaller than the cross-sectional size of the second limiting member (7).

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