Stiffened top and bottom angle steel flush end plate connecting beam column joint and connecting method thereof

Abstract

The invention relates to a reinforced top and bottom angle steel flush end plate connecting beam column joint and a connecting method thereof. The beam-column joint comprises an H-shaped steel column, and the H-shaped steel column comprises steel column flanges arranged in parallel and a steel column web arranged between the steel column flanges; the H-shaped steel beam comprises an upper steel beam flange and a lower steel beam flange which are arranged in parallel, and a steel beam web is arranged between the upper steel beam flange and the lower steel beam flange; the flush end plates are welded to the steel beams and flush with flanges of the steel columns; the top stiffening angle steel is arranged at the top of the steel beam; the bottom stiffening angle steel is arranged at the bottom of the steel beam; the flush end plates, the top stiffening angle steel and the bottom stiffening angle steel are connected with the steel column flanges through bolts, the top stiffening angle steel and the upper steel beam flanges are connected through bolts, and the bottom stiffening angle steel and the lower steel beam flanges are connected through bolts. Compared with the prior art, full bolt connection is adopted, the field assembly efficiency is improved, and the joint has the excellent full-rigidity and full-strength joint mechanical characteristics.

Description

Technical Field

[0001] The invention relates to the technical field of building structures, in particular to a beam-column node connected with a flush end plate of a stiffened top and bottom angle steel and a connection method thereof. Background Art

[0002] The beam-column joint is the key part for realizing load transfer and deformation coordination in the steel frame structure system, which affects the continuity and stability of the structure and plays a decisive role in the overall load bearing of the steel frame. There are three main types of typical steel frame node connection forms: full welding connection, bolt-weld hybrid connection and full bolt connection.

[0003] Compared with welded nodes, fully bolted nodes prevent weld failure from causing the node to present a brittle failure mode, and avoid on-site welding work, which reduces the construction difficulty, improves construction efficiency, and ensures construction quality. Typical fully bolted nodes are mainly composed of angle steels, end plates and other components. However, due to the bending deformation of end plates and angle steels under lateral loads, most of these nodes belong to the category of semi-rigid nodes. When dealing with high rigidity requirements, it is necessary to increase the thickness or weld stiffening ribs to achieve the design goals, but the improvement effect is limited. Specifically, increasing the thickness of the end plate or angle steel is likely to cause a brittle failure mode of bolt breakage when the node is damaged; while welding stiffening ribs has limited effect on improving the stiffness of angle steel nodes, and is not conducive to the transportation of end plate nodes. In fact, for common domestic node forms (column welding short beams, short beams and beams splicing), collision problems are also prone to occur during transportation, leading to installation defects.

[0004] CN111119335A discloses an energy-dissipating steel structure beam-column node and its installation method, wherein the node comprises an H-shaped steel column, an H-shaped steel beam connected to the H-shaped steel column through a double-layer web end plate connector, and an upper flange connector plate and a lower flange connector plate for connecting the double-layer web end plate connector and the H-shaped steel beam. When the node is bent, the tensile angle steel is the main load-bearing component, while the double-sided angle steel component connecting the steel beam web and the steel column flange has a very limited effect on the node stiffness and strength, so the bending stiffness and strength of the node under static load still need to be improved.

[0005] CN111058533A discloses a friction energy dissipation type assembled beam-column connection node, including an H-shaped steel column and an H-shaped steel beam, wherein the upper flange and the lower flange of the H-shaped steel beam are connected to the column flange of the H-shaped steel column through flange connectors, and the beam webs on both sides of the H-shaped steel beam are connected to the column flange of the H-shaped steel column through web connectors, and the H-shaped steel beam, the lower flange connector and the web connector are respectively connected to the H-shaped steel column and the H-shaped steel beam through multiple sets of high-strength bolts, and the other bolt holes on the beam web are horizontal oblong bolt holes, and the bolt holes on the lower flange connector connected to the lower flange cover plate are horizontal oblong bolt holes. However, during on-site installation, this solution requires the beam web to be inserted into the gap between the double-layer webs, and assembled and positioned at multiple locations such as the web pad, the limit plate, the energy dissipation plate and the energy dissipation column, which requires many steps and requires more precise manufacturing and on-site coordination.

[0006] In summary, the typical node form of the current steel frame is difficult to take into account the rigidity, strength and construction convenience. Therefore, it is urgent to develop a new type of beam-column node with full bolt connection. Summary of the invention

[0007] The purpose of the present invention is to provide a beam-column node and a connection method thereof with a flush end plate connected with a stiffened top and bottom angle steel in order to overcome the defect that the existing nodes cannot take into account the rigidity, strength and construction convenience.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] The present invention first provides a beam-column node connected with a flush end plate of a stiffened top and bottom angle steel, the beam-column node comprising:

[0010] Steel column; the steel column is an H-shaped steel column, which includes parallel steel column flanges and a steel column web disposed between the steel column flanges;

[0011] Steel beam; the steel beam is an H-shaped steel beam, which includes an upper steel beam flange and a lower steel beam flange arranged in parallel, and a steel beam web is provided between the upper steel beam flange and the lower steel beam flange;

[0012] Flush end plates welded to the steel beams and flush with the steel column flanges;

[0013] Top stiffening angle steel located at the top of the steel beam;

[0014] Bottom stiffening angle steel installed at the bottom of the steel beam;

[0015] The flush end plate, the top stiffening angle steel, the bottom stiffening angle steel and the steel column flange, the top stiffening angle steel and the upper steel beam flange, and the bottom stiffening angle steel and the lower steel beam flange are all connected by bolts.

[0016] Furthermore, a stiffening plate is provided between the steel column flanges of the steel column, and the stiffening plate is perpendicular to both the steel column flanges and the steel column web.

[0017] Furthermore, there are two stiffening plates, and the two stiffening plates are respectively flush with the upper steel beam flange and the lower steel beam flange.

[0018] Furthermore, the upper edge of the flush end plate is flush with the top of the upper steel beam flange, and the lower edge of the flush end plate is flush with the bottom of the lower steel beam flange.

[0019] Furthermore, the center line of the flush end plate, the center line of the steel column web and the center line of the steel beam web are aligned and coplanar.

[0020] Furthermore, the center line of the top stiffening angle steel and the center line of the bottom stiffening angle steel are both aligned and coplanar with the center line of the steel column web.

[0021] Furthermore, the top stiffening angle steel includes a top angle steel and a top stiffening rib.

[0022] Furthermore, the top angle steel comprises a short limb of the top angle steel and a long limb of the top angle steel which are vertically arranged, and the top stiffening rib connects the plate surface of the short limb of the top angle steel and the plate surface of the long limb of the top angle steel.

[0023] Furthermore, the short limb of the top angle steel fits with the outer wall of the steel column flange, and the long limb of the top angle steel fits with the top surface of the upper steel beam flange.

[0024] Furthermore, the bottom stiffening angle steel includes a bottom angle steel and a bottom stiffening rib.

[0025] Furthermore, the bottom angle steel comprises a short limb of the bottom angle steel and a long limb of the bottom angle steel which are vertically arranged, and the bottom stiffening rib connects the plate surface of the short limb of the bottom angle steel and the plate surface of the long limb of the bottom angle steel.

[0026] Furthermore, the short limb of the bottom angle steel fits with the outer wall of the steel column flange, and the long limb of the bottom angle steel fits with the top surface of the lower steel beam flange.

[0027] Furthermore, the flush end plate is provided with threaded holes on the plate surface on both sides of the steel beam web, and corresponding threaded holes are provided on the steel column flange.

[0028] Furthermore, bolt holes are provided on both sides of the upper steel beam flange and the lower steel beam flange separated by the steel beam web, and corresponding bolt holes are provided on the top stiffening angle steel and the bottom stiffening angle steel.

[0029] Furthermore, the bolts are all high-strength friction bolts.

[0030] Furthermore, the thickness of the flush end plate is preferably 0.9 to 1.2 times the thickness of the beam flange (upper steel beam flange), and the thickness of the top angle steel is preferably 0.8 to 1.0 times the thickness of the beam flange.

[0031] The present invention also provides a method for connecting a beam-column node by connecting a flush end plate with a stiffened top and bottom angle steel, the method comprising the following steps:

[0032] S1: After the bottom stiffening angle steel and the steel column are initially positioned, they are connected by bolts;

[0033] S2: Place the steel beam with the flush end plate welded on the bottom stiffening angle steel, and connect the flush end plate to the steel column flange and the bottom stiffening angle steel to the lower steel beam flange by bolts;

[0034] S3: Place the top stiffening angle steel on top of the steel beam, and connect the top stiffening angle steel to the flange of the steel column and to the flange of the upper steel beam by bolts.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The beam-column node connected by the stiffened top and bottom angle steel and the flush end plate of the present invention is composed of a steel column, a steel beam, a top stiffening angle steel, a bottom stiffening angle steel and a flush end plate. It uses full bolt connection, which significantly improves the efficiency of on-site node assembly and has excellent node mechanical characteristics of full rigidity and full strength. The node achieves a good balance of rigidity, strength and construction convenience through the combination of the flush end plate and the stiffening angle steel; the design of the flush end plate improves the convenience and safety of transportation and stacking, and the stiffening angle steel effectively improves the mechanical properties of the node. Finite element analysis shows that the beam-column node of the present invention is superior to the traditional node in terms of bearing capacity and stiffness.

[0037] (2) The fully bolted steel frame beam-column node of the present invention uses flush end plates to ensure the convenience of transportation of the node, and the use of stiffening angle steels ensures the convenience of on-site installation of the node. The reasonable combination of stiffening angle steels and flush end plates makes the beam-column node of the present invention have higher rigidity and strength, and can flexibly respond to design requirements.

[0038] (3) The beam-column node of the present invention adopts a scheme of using flush end plates and angle steels in combination, which can controllably realize the node properties and flexibly respond to design requirements. By welding stiffening ribs on the angle steels, the tensile strength of the angle steel components is improved, the stiffness and strength of the nodes are improved, and the performance upper limit of the nodes is further broadened.

[0039] (4) The node connection method of the present invention is simple and efficient and can be quickly assembled on site, which not only improves the construction quality and efficiency, but also significantly reduces the possibility of on-site installation defects. It has a high promotion value, helps to improve the safety and design flexibility of building structures, and is suitable for application scenarios of various green buildings and prefabricated buildings.

[0040] (5) The ends of the steel beams of the present invention are welded with the flush end plates in the factory and then transported to the site for installation, thus overcoming the problem of collisions that easily occur at the protruding parts of the column components of the elongated end plate nodes or welded short beams during transportation, avoiding defects in on-site installation, and ensuring construction quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a structural schematic diagram of the beam-column node of the present invention.

[0042] Figure 2 It is a schematic diagram of the assembly of the beam-column node of the present invention.

[0043] Figure 3 It is a schematic structural diagram of the steel column of the present invention.

[0044] Figure 4 It is a structural schematic diagram of the steel beam of the present invention.

[0045] Figure 5 It is a schematic structural diagram of the top stiffening angle steel of the present invention.

[0046] Figure 6 It is a schematic structural diagram of the bottom stiffening angle steel of the present invention.

[0047] Figure 7 This is a schematic diagram of the stacking of the connection node, the elongated end plate node, and the stiffened elongated end plate node according to Example 4 of the present invention.

[0048] Figure 8 A schematic diagram of a finite element node model for meshing connection nodes according to Example 4 of the present invention.

[0049] Fig. 9 The moment-load curves of three types of nodes with top angle steel stiffeners, bottom angle steel stiffeners and full stiffeners are shown.

[0050] Fig.10 Moment-rotation curves for three types of nodes with only top stiffeners, only bottom stiffeners, and both top and bottom stiffeners

[0051] Fig.11 Moment-load curves for connection nodes with the same end plate thickness and different top angle thicknesses.

[0052] Fig.12The ultimate bearing capacity diagrams for a series of fully bolted steel frame beam-column joints with different sizes.

[0053] Description of the markings in the figure:

[0054] 1-steel column, 11-steel column flange, 12-steel column web, 13-stiffening plate;

[0055] 2-steel beam, 21-upper steel beam flange, 22-lower steel beam flange, 23-steel beam web;

[0056] 3-Flush end plate;

[0057] 4-top stiffening angle steel, 41-top angle steel, 411-top angle steel short leg, 412-top angle steel long leg, 42-top stiffening rib;

[0058] 5-bottom stiffening angle steel, 51-bottom angle steel, 511-bottom angle steel short leg, 512-bottom angle steel long leg; 52-bottom stiffening rib;

[0059] 6-Bolts. DETAILED DESCRIPTION

[0060] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0061] In the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0063] Embodiment 1:

[0064] This embodiment provides a beam-column node connected with a stiffened top and bottom angle steel and a flush end plate. The beam-column node specifically includes a steel column 1, a steel beam 2, a flush end plate 3, a top stiffening angle steel 4, a bottom stiffening angle steel 5 and bolts 6.

[0065] like Figure 1 As shown, the steel column 1 of this embodiment is an H-shaped steel column, which includes parallel steel column flanges 11 and a steel column web 12 arranged between the steel column flanges 11. The steel beam 2 is an H-shaped steel beam, which includes an upper steel beam flange 21 and a lower steel beam flange 22 arranged in parallel, and a steel beam web 23 is arranged between the upper steel beam flange 21 and the lower steel beam flange 22. The flush end plate 3 is welded to the steel beam 2 and is flush with the steel column flange 11. The top stiffening angle steel 4 is arranged at the top of the steel beam 2, and the bottom stiffening angle steel 5 is arranged at the bottom of the steel beam 2.

[0066] In this embodiment, the flush end plate 3, the top stiffening angle steel 4, the bottom stiffening angle steel 5 and the steel column flange 11, the top stiffening angle steel 4 and the upper steel beam flange 21, and the bottom stiffening angle steel 5 and the lower steel beam flange 22 are all connected by bolts 6.

[0067] like Figure 2 As shown, the connection method of the beam-column node with the flush end plate of the stiffened top and bottom angle steel of this embodiment includes the following steps:

[0068] S1: After the bottom stiffening angle steel 5 and the steel column 1 are initially positioned, they are connected by bolts 6;

[0069] S2: placing the steel beam 2 welded with the flush end plate 3 on the bottom stiffening angle steel 5, and connecting the flush end plate 3 and the steel column flange 11 as well as the bottom stiffening angle steel 5 and the lower steel beam flange 22 by bolts 6;

[0070] S3: Place the top stiffening angle steel 4 above the steel beam 2, and connect the top stiffening angle steel 4 to the steel column flange 11 and to the upper steel beam flange 21 through bolts 6.

[0071] The beam-column node connected by the flush end plate with the stiffened top and bottom angle steel in this embodiment is composed of a steel column 1, a steel beam 2, a top stiffening angle steel 4, a bottom stiffening angle steel 5 and a flush end plate 3. It is connected by full bolts, which significantly improves the efficiency of on-site assembly of the beam-column node and has excellent node mechanical characteristics of full rigidity and full strength. The design of the flush end plate 3 improves the convenience and safety of transportation and stacking, and the stiffening angle steel effectively improves the mechanical properties of the node. The beam-column node achieves a good balance of stiffness, strength and construction convenience through the combination of the flush end plate 3 and the stiffening angle steel.

[0072] Embodiment 2:

[0073] This embodiment provides a beam-column node connected with a stiffened top and bottom angle steel and a flush end plate. The beam-column node specifically includes a steel column 1, a steel beam 2, a flush end plate 3, a top stiffening angle steel 4, a bottom stiffening angle steel 5 and bolts 6.

[0074] The difference from Example 1 is that Figure 3 As shown, a stiffening plate 13 is provided between the steel column flanges 11 of the steel column 1 of this embodiment, and the stiffening plate 13 is perpendicular to both the steel column flanges 11 and the steel column web 12. Two stiffening plates 13 are provided, and the two stiffening plates 13 are respectively flush with the upper steel beam flange 21 and the lower steel beam flange 22.

[0075] like Figure 4 As shown, the upper edge of the flush end plate 3 of this embodiment is flush with the top of the upper steel beam flange 21, and the lower edge of the flush end plate 3 is flush with the bottom of the lower steel beam flange 22. The center line of the flush end plate 3, the center line of the steel column web 12, and the center line of the steel beam web 23 of this embodiment are aligned and coplanar.

[0076] In this embodiment, the center line of the top stiffening angle steel 4 and the center line of the bottom stiffening angle steel 5 are both aligned and coplanar with the center line of the steel column web 12 .

[0077] The flush end plate 3 of this embodiment is provided with threaded holes on the plate surface on both sides of the steel beam web 23, and corresponding threaded holes are provided on the steel column flange 11. Bolt holes are provided on both sides of the upper steel beam flange 21 and the lower steel beam flange 22 separated by the steel beam web 23, and corresponding bolt holes are provided on the top stiffening angle steel 4 and the bottom stiffening angle steel 5. The bolts 6 used in this embodiment are all high-strength friction bolts 6.

[0078] Embodiment 3:

[0079] This embodiment provides a beam-column node connected with a stiffened top and bottom angle steel and a flush end plate. The beam-column node specifically includes a steel column 1, a steel beam 2, a flush end plate 3, a top stiffening angle steel 4, a bottom stiffening angle steel 5 and bolts 6.

[0080] The difference from Example 1 is that Figure 5 As shown, the top stiffening angle steel 4 of this embodiment includes a top angle steel 41 and a top stiffening rib 42. The top angle steel 41 includes a top angle steel short limb 411 and a top angle steel long limb 412 arranged vertically, and the top stiffening rib 42 connects the plate surface of the top angle steel short limb 411 and the plate surface of the top angle steel long limb 412. The top angle steel short limb 411 is fitted with the outer wall of the steel column flange 11, and the top angle steel long limb 412 is fitted with the top surface of the upper steel beam flange 21.

[0081] like Figure 6As shown, the bottom stiffening angle steel 5 of this embodiment includes a bottom angle steel 51 and a bottom stiffening rib 52. The bottom angle steel 51 includes a bottom angle steel short limb 511 and a bottom angle steel long limb 512 arranged vertically, and the bottom stiffening rib 52 connects the plate surface of the bottom angle steel short limb 511 and the plate surface of the bottom angle steel long limb 512. The bottom angle steel short limb 511 is in contact with the outer wall of the steel column flange 11, and the bottom angle steel long limb 512 is in contact with the top surface of the lower steel beam flange 22.

[0082] Embodiment 4:

[0083] A full bolt 6 connection steel frame beam-column node in one embodiment of the present invention comprises a steel column 1, a steel beam 2 with an end welded flush with an end plate 3, a top stiffening angle steel 4, a bottom stiffening angle steel 5 and a high-strength bolt 6. The prefabricated steel column 1, the steel beam 2 with an end welded flush with an end plate 3, the top stiffening angle steel 4, the bottom stiffening angle steel 5 and the high-strength bolt 6 enable on-site assembly of the node, greatly shortening the construction period, reducing the construction difficulty and cost, and improving the construction convenience. At the same time, the above-mentioned prefabricated components make each component easy to transport, store and install, thereby improving the construction efficiency.

[0084] The steel column 1 includes two parallel steel column flanges 11 and a steel column web 12 vertically arranged between the two steel column flanges 11. A stiffening plate 13 perpendicular to both the steel column flanges 11 and the steel column web 12 is also arranged between the two parallel steel column flanges 11. Two parallel stiffening plates 13 are arranged between the two parallel steel column flanges 11. The stiffening plates 13 are respectively at the same horizontal position with the upper steel beam flange 21 and the lower steel beam flange 22 of the steel beam 2, thereby enhancing the overall stiffness and bearing capacity of the beam-column node.

[0085] The steel beam 2 is an H-section steel beam, including an upper steel beam flange 21 and a lower steel beam flange 22 arranged in parallel, and a steel beam web 23 arranged vertically between the two flanges. A flush end plate 3 is welded to the end of the steel beam 2 close to the steel column 1, and the upper and lower edges of the flush end plate 3 are respectively aligned with the upper steel beam flange 21 and the lower steel beam flange 22, thereby improving the plastic bearing capacity of the beam section. Two rows of bolt holes are respectively arranged along the length direction of the flush end plate 3, and are connected to the steel column 1 at the middle position by high-strength bolts 6.

[0086] In this embodiment, two rows of flange plate bolt holes are prefabricated on the steel column flange 11 along the length direction of the flange, and are respectively connected to the top stiffening angle steel 4, the flush end plate 3 and the bottom stiffening angle steel 5 through high-strength bolts 6.

[0087] The top stiffening angle steel 4 of this embodiment is composed of a top angle steel 41 and a top stiffening rib 42 welded to the top angle steel 41. Two rows of bolt holes are prefabricated on the top angle steel 41 along the direction of the short limb 411 and the long limb 412 of the top angle steel, respectively. The bolt holes in the direction of the short limb 411 of the top angle steel are aligned with the bolt holes on the upper part of the steel column flange 11, and the bolt holes in the direction of the long limb 412 of the top angle steel are aligned with the bolt holes on the upper steel beam flange 21. The top stiffening rib 42 is provided with a trimming and a through-welding hole. The reserved welding port is convenient for welding with the top angle steel 41, and the trimming is provided to further improve the rigidity.

[0088] The bottom stiffening angle steel 5 of this embodiment is composed of a bottom angle steel 51 and a bottom stiffening rib 52 welded to the bottom angle steel 51. Two rows of bolt holes are prefabricated on the bottom angle steel 51 along the direction of the short limb 511 and the long limb 512 of the bottom angle steel, respectively. The bolt holes in the direction of the short limb 511 of the bottom angle steel are aligned with the bolt holes on the upper part of the steel column flange 11, and the bolt holes in the direction of the long limb 512 of the bottom angle steel are aligned with the bolt holes on the lower steel beam flange 22. The bottom stiffening rib 52 is provided with a trimming and a through-welding hole. The reserved welding port is convenient for welding with the bottom angle steel 51, and the trimming is provided to further improve the rigidity.

[0089] Figure 7 They are steel beam 2 components with flush end plates 3 welded to them ( Figure 7 a) Welded stiffened elongated end plate ( Figure 7 b) Steel beam 2 member and welder extension end plate ( Figure 7 c) The stacking method of the steel beam 2 components. In this embodiment, the finite element software ABAQUS is used to analyze the mechanical properties of the fully bolted steel frame beam-column nodes, and compared with the welded elongated end plate nodes and the welded stiffened elongated end plate nodes. The finite element model node area mesh division is as follows: Figure 8 shown.

[0090] Each component is simulated using a three-dimensional eight-node hexahedral reduced integration unit C3D8R. Steel column 1, steel beam 2, flush end plate 3, top stiffening angle 4 and bottom stiffening angle 5 are all made of Q355 steel. "Hard" contact is used in the normal direction of each contact surface, and the friction coefficient is taken as 0.35. The top and bottom of steel column 1 constrain the translational and rotational degrees of freedom in three directions, and the beam end constrains the out-of-plane degrees of freedom. A vertical load is applied to the beam end. This model uses the temperature method to accurately apply the preload of the bolts, and introduces a micro-fracture model to simulate the node fracture behavior in order to better analyze the mechanical behavior of the node throughout the process.

[0091] The bending moment-rotation curve obtained by finite element calculation is as follows: Fig. 9As shown in the figure, it can be seen that the fully bolted steel frame beam-column node of this embodiment has superior performance. Compared with the extended end plate node, it has better stiffness and higher bearing capacity. Although the rotation capacity is reduced, it is still within an acceptable range. Compared with the stiffened extended end plate node, it has similar stiffness, higher bearing capacity and better rotation capacity.

[0092] Fig.10 The bending moment-rotation curves of three nodes are respectively provided with only the top stiffening rib 42, only the bottom stiffening rib 52, and both the top stiffening rib 42 and the bottom stiffening rib 52. Figure 8 It can be seen that the top angle steel 41 is the main load-bearing component, and welding the top stiffening rib 42 on the top angle steel 41 is an effective solution to improve the stiffness and strength of the node; welding the bottom stiffening rib 52 on the bottom angle steel 51 has a greater impact on the bearing capacity and also has a certain impact on the initial stiffness.

[0093] Fig.11 It is a set of fully bolted steel frame beam-column nodes with the same thickness of flush end plates 3 and different thicknesses of top angle steels 41, where A represents the thickness of the top angle steel 41 (i.e., the tension angle steel) and P represents the thickness of the end plate 3. Fig.10 It has been shown that the top angle steel 41 is the main load-bearing member. Fig.11 It can be seen that the test selected a flush end plate 3 of the same thickness and set top angle steels 41 of different thicknesses on the top to form several fully bolted beam-column node specimens. The horizontal axis is the rotation angle and the vertical axis is the bending moment. By comparing the bending moment-rotation angle curves of these specimens, the following conclusions can be drawn: (1) Within the small rotation angle range, the trends of the curves are relatively close, indicating that the initial stiffness of the flush end plate 3 and the bolt group are relatively similar. As the rotation angle increases, the top angle steels of different thicknesses begin to show differences. When the top angle steel 41 is thicker, it can provide better restraint capacity, making the overall stiffness of the node decay more slowly. (2) It can be seen from the curve that with the increase in the thickness of the top angle steel 41, the bearing capacity of the node at a larger rotation angle is significantly improved, and the maximum bending moment value also increases accordingly. This shows that appropriately increasing the thickness of the top angle steel 41 can effectively improve the ultimate bearing capacity of the fully bolted node.

[0094] Fig.12The figure shows a series of fully bolted steel frame beam-column nodes of different sizes. The horizontal axis is the angle steel coefficient, the vertical axis is the ultimate bearing capacity, and different curves represent different end plate coefficients. The angle steel coefficient is the ratio of the thickness of the top angle steel 41 (tension angle steel) to the thickness of the beam flange, and the end plate coefficient is the ratio of the thickness of the flush end plate 3 to the thickness of the beam flange. These two coefficients are selected to non-dimensionalize the thickness of the flush end plate 3 and the top angle steel 41, unify the measurement scale, and the results can be compared and promoted in a wider engineering context. The low red dotted line represents the yield bearing capacity of the beam section, and the high red dotted line represents the plastic bearing capacity of the beam section. The bearing capacity of a well-designed beam-column node is generally considered to be no less than the plastic bearing capacity of the beam section, so the plastic bearing capacity is selected as the judgment standard.

[0095] Depend on Fig.12 It can be seen that as the angle steel coefficient (horizontal coordinate) increases from 0.7 to about 1.0, most curves show a gradually rising trend, indicating that moderately thickening the top angle steel can provide stronger constraints and bearing capacity, so that the ultimate bearing capacity of the node is correspondingly improved. When the angle steel coefficient continues to increase to above 1.0-1.1, some curves show a peak value and then a slight decrease, which indicates that when the angle steel is too thick, its greater stiffness causes the angle steel to rotate as a rigid body as a whole, which easily leads to local buckling of the contact part between the beam flange and the angle steel, resulting in premature failure of the node; the difference between different end plate coefficients (curves) is also quite obvious. Usually, as the end plate coefficient increases (the thicker the end plate), the overall position of the curve is also higher, indicating that the ultimate bearing capacity of this series of specimens is greater. From the peak positions of multiple curves, it can be seen that the thickness of the angle steel and the end plate relative to the beam flange is not the thicker the better, but there is an optimal match within a certain range. For actual engineering, the appropriate "angle steel coefficient-end plate coefficient" combination should be found in combination with design requirements (including bearing capacity, stiffness, ductility and cost). According to the above analysis results, the recommended range of the thickness of the flush end plate 3 is 0.9 to 1.2 of the beam flange thickness, and the recommended range of the thickness of the top angle steel 41 (tension angle steel) is 0.8 to 1.0 of the beam flange thickness.

[0096] The above finite element analysis results prove that the fully bolted stiffened top and bottom angle steel flush end plate connection beam-column node of the present invention has the following advantages:

[0097] (1) Good stiffness and strength performance. The stiffened angle steel components effectively improve the stiffness performance of the node and enhance the bearing capacity of the node. The design of stiffened angle steels at the top and bottom takes into account the complex stress conditions that the node may face under reciprocating loads.

[0098] (2) Flexible design and convenient application. The combined use of stiffened angle steel and flush end plate 3 can improve node performance, flexibly respond to different design requirements, and avoid the difficulties in responding to temporary changes in requirements during on-site construction of the end plate node.

[0099] (3) Convenient transportation and high safety. Figure 7 It can be seen that the steel beam 2 components welded with flush end plates 3 can be stacked at the same time in greater numbers than welded elongated end plate nodes and welded stiffened elongated end plate nodes, and will not cause collisions and lead to local defects.

[0100] The connection method of the fully bolted steel frame beam-column node of this embodiment specifically includes the following steps:

[0101] S1: After preliminary positioning of the bottom stiffening angle steel 5 and the steel column 1, connect them through high-strength bolts 6, ensuring that the bolt holes of the bottom stiffening angle steel 5 are aligned with the bolt holes at the corresponding positions of the steel column flange 11; ensuring that the bottom stiffening angle steel 5 is stably installed on the steel column flange 11;

[0102] S2: Place one side of the steel beam 2 welded flush with the end plate 3 on the bottom stiffening angle steel 5, align the bolt holes of the flush end plate 3 with the bolt holes at the corresponding positions of the steel column flange 11, and connect them through high-strength bolts 6; align the bolt holes on the lower steel beam flange 22 with the bolt holes on the long limb 512 of the bottom angle steel, and connect them through high-strength bolts 6;

[0103] S3: Place the top stiffening angle steel 4 above the upper steel beam flange 21, align the short leg 411 of the top angle steel with the bolt holes of the steel column flange 11, align the bolt holes of the long leg 412 of the top angle steel with the bolt holes of the upper steel beam flange 21, and connect them respectively through high-strength bolts 6.

[0104] In summary, the fully bolted beam-column node of the present invention has good stiffness and strength performance through the coordinated use of the top stiffening angle steel 4, the bottom stiffening angle steel 5 and the flush end plate 3, and has the advantages of flexible design and convenient application, and can flexibly respond to different design goals.

[0105] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A beam-column node connected with a stiffened top and bottom angle steel and a flush end plate, the beam-column node comprising: A steel column (1); the steel column (1) is an H-shaped steel column, comprising steel column flanges (11) arranged in parallel and a steel column web (12) arranged between the steel column flanges (11); A steel beam (2); the steel beam (2) is an H-shaped steel beam, comprising an upper steel beam flange (21) and a lower steel beam flange (22) arranged in parallel, and a steel beam web (23) is arranged between the upper steel beam flange (21) and the lower steel beam flange (22); A flush end plate (3) welded to the steel beam (2) and flush with the steel column flange (11); A top stiffening angle steel (4) provided on the top of the steel beam (2); A bottom stiffening angle steel (5) provided at the bottom of the steel beam (2); The flush end plate (3), the top stiffening angle steel (4), the bottom stiffening angle steel (5) and the steel column flange (11), the top stiffening angle steel (4) and the upper steel beam flange (21), and the bottom stiffening angle steel (5) and the lower steel beam flange (22) are all connected by bolts (6).

2. A beam-column node connected by a reinforced top and bottom angle steel flush end plate according to claim 1, characterized in that: A stiffening plate (13) is provided between the steel column flanges (11) of the steel column (1), and the stiffening plate (13) is perpendicular to both the steel column flanges (11) and the steel column web (12).

3. A beam-column node connected by a reinforced top and bottom angle steel flush end plate according to claim 2, characterized in that: The stiffening plates (13) are provided in two pieces, and the two stiffening plates (13) are respectively flush with the upper steel beam flange (21) and the lower steel beam flange (22).

4. A beam-column node connected by a reinforced top and bottom angle steel flush end plate according to claim 1, characterized in that: The upper edge of the flush end plate (3) is flush with the top of the upper steel beam flange (21), and the lower edge of the flush end plate (3) is flush with the bottom of the lower steel beam flange (22).

5. The beam-column node connected by a reinforced top and bottom angle steel flush end plate according to claim 1, characterized in that: The center line of the flush end plate (3), the center line of the steel column web (12), and the center line of the steel beam web (23) are aligned and coplanar.

6. The beam-column node connected by a reinforced top and bottom angle steel flush end plate according to claim 1, characterized in that: The center line of the top stiffening angle steel (4) and the center line of the bottom stiffening angle steel (5) are both aligned and coplanar with the center line of the steel column web (12).

7. The beam-column node connected by a reinforced top and bottom angle steel flush end plate according to claim 1, characterized in that: The top stiffening angle steel (4) comprises a top angle steel (41) and a top stiffening rib (42); The top angle steel (41) comprises a top angle steel short limb (411) and a top angle steel long limb (412) which are vertically arranged, and the top stiffening rib (42) connects the plate surface of the top angle steel short limb (411) and the plate surface of the top angle steel long limb (412); The short limb (411) of the top angle steel is fitted with the outer wall of the steel column flange (11), and the long limb (412) of the top angle steel is fitted with the top surface of the upper steel beam flange (21).

8. The beam-column node connected by a reinforced top and bottom angle steel flush end plate according to claim 1, characterized in that: The bottom stiffening angle steel (5) comprises a bottom angle steel (51) and a bottom stiffening rib (52); The bottom angle steel (51) comprises a bottom angle steel short limb (511) and a bottom angle steel long limb (512) which are vertically arranged, and the bottom stiffening rib (52) connects the plate surface of the bottom angle steel short limb (511) and the plate surface of the bottom angle steel long limb (512); The short limb (511) of the bottom angle steel is fitted with the outer wall of the steel column flange (11), and the long limb (512) of the bottom angle steel is fitted with the top surface of the lower steel beam flange (22).

9. The beam-column node connected by a reinforced top and bottom angle steel flush end plate according to claim 1, characterized in that: The flush end plate (3) is provided with threaded holes on the plate surface on both sides of the steel beam web (23), and the steel column flange (11) is provided with corresponding threaded holes; Bolt holes are provided on both sides of the upper steel beam flange (21) and the lower steel beam flange (22) separated by the steel beam web (23), and corresponding bolt holes are provided on the top stiffening angle steel (4) and the bottom stiffening angle steel (5).

10. A method for connecting beam-column nodes by flushing end plates with stiffening top and bottom angle steels as claimed in any one of claims 1 to 9, characterized in that: The connection method comprises the following steps: S1: After preliminary positioning, the bottom stiffening angle steel (5) and the steel column (1) are connected by bolts (6); S2: placing the steel beam (2) welded with the flush end plate (3) on the bottom stiffening angle steel (5), and connecting the flush end plate (3) and the steel column flange (11) as well as the bottom stiffening angle steel (5) and the lower steel beam flange (22) by bolts (6); S3: Place the top stiffening angle steel (4) above the steel beam (2), and connect the top stiffening angle steel (4) to the steel column flange (11) and the top stiffening angle steel (4) to the upper steel beam flange (21) by bolts (6).

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