Unequal-height steel beam assembly type splicing joint

Abstract

The invention relates to the technical field of steel structures, and discloses an unequal-height steel beam assembly type splicing joint which is characterized in that a rectangular steel pipe beam comprises a first upper flange, a first lower flange, a left web plate and a right web plate; the I-shaped steel beam comprises a second upper flange and a second lower flange, the second upper flange is flush with the first upper flange in height, and a height difference exists between the second lower flange and the first lower flange; the upper flange connecting plate is connected with the first upper flange and the second upper flange through a first group of high-strength bolts; the lower flange connecting piece is connected with the first lower flange and the second lower flange through a second group of high-strength bolts; the I-shaped steel beam end plate is fixed to the end, close to the rectangular steel pipe beam, of the I-shaped steel beam. According to the unequal-height steel beam connecting structure, full-bolt assembly construction can be achieved, meanwhile, it is ensured that internal force transmission between unequal-height steel beams is continuous and reliable, and the unequal-height steel beam connecting structure has the good energy dissipation capacity.

Description

Technical Field

[0001] This invention relates to the field of steel structure technology, and in particular to a prefabricated splicing node for steel beams of unequal height. Background Technology

[0002] In prefabricated steel structure buildings, to optimize both economy and performance, steel beams with different cross-sectional forms are often used in different sections. For example, rectangular steel tube beams with high torsional stiffness and good local stability are used in areas with large bending moments and complex stresses at the beam ends, while I-beams, which offer better economic benefits, are used in the mid-span area. Due to different stress requirements, the cross-sectional heights of these two types of beams are often inconsistent, creating the problem of unequal height connections. Traditional node connection methods, such as on-site welding or conventional bolt connections, cannot efficiently and reliably solve the problem of continuous transmission of internal forces (especially axial forces and shear forces caused by bending moments) between beams of unequal heights without affecting structural performance. On-site welding quality is difficult to control, easily introducing initial defects that affect the seismic performance and ductility of the joint; while simple bolted plates may not be able to accommodate the height difference between flanges, resulting in unclear force transmission paths and stress concentration, failing to achieve the seismic design concept of "strong nodes, weak components". Summary of the Invention

[0003] The purpose of this invention is to provide a prefabricated splicing node for steel beams of unequal height, which aims to solve or improve at least one of the above-mentioned technical problems, enabling fully bolted prefabricated construction, while ensuring continuous and reliable internal force transmission between steel beams of unequal height, and having good energy dissipation capacity.

[0004] To achieve the above objectives, the present invention provides the following solution: The present invention provides an assembled splicing node for steel beams of unequal heights, comprising:

[0005] A rectangular steel tube beam includes a first upper flange, a first lower flange, a left web, and a right web;

[0006] The I-shaped steel beam includes a second upper flange and a second lower flange. The second upper flange is at the same height as the first upper flange, and the second lower flange has a height difference from the first lower flange.

[0007] The upper flange connecting plate is connected to the first upper flange and the second upper flange by a first set of high-strength bolts;

[0008] The lower flange connector is connected to the first and second lower flanges by a second set of high-strength bolts;

[0009] The end plate of the I-beam is fixed to the end of the I-beam near the rectangular steel pipe beam;

[0010] A pair of angle steel connectors are connected to the left web, the right web, and the end plate of the I-beam via a third set of high-strength bolts.

[0011] Optionally, the first set of high-strength bolts includes a plurality of upper connecting bolts, which are connected between the upper flange connecting plate and the first upper flange and the second upper flange.

[0012] Optionally, the lower flange connector includes a first horizontal steel plate, a second horizontal steel plate, a vertical steel plate, and a pair of stiffening ribs. The first horizontal steel plate, the vertical steel plate, and the second horizontal steel plate are connected in sequence to form a Z-shaped structure. The stiffening ribs are connected to the side of the Z-shaped structure. The vertical steel plate is used to fill the height difference between the first lower flange and the second lower flange.

[0013] Optionally, the second group of high-strength bolts includes:

[0014] Multiple first lower connecting bolts are connected between the first horizontal steel plate and the first lower flange;

[0015] Multiple second lower connecting bolts are connected between the second horizontal steel plate and the second lower flange.

[0016] Optionally, the angle steel connector includes a first side plate and a second side plate that are perpendicular to each other, the two first side plates corresponding to the left web and the right web respectively, and the second side plate corresponding to the end plate of the I-beam.

[0017] Optionally, the third group of high-strength bolts includes:

[0018] Multiple first-side connecting bolts are connected between a pair of first-side plates and the left web plate and the right web plate;

[0019] Multiple second-side connecting bolts connect a pair of second-side plates to the end plates of the I-beam.

[0020] Optionally, the stiffening ribs are rhomboid in shape.

[0021] Optionally, the number and specifications of the upper connecting bolts and the size of the upper flange connecting plate are determined based on the equal strength condition with the net cross-sectional area of ​​the first upper flange and the second upper flange.

[0022] Optionally, the quantity and specifications of the first and second lower connecting bolts, as well as the dimensions of the first horizontal steel plate, the second horizontal steel plate, the vertical steel plate, and the stiffening rib, are determined based on strength conditions such as the net cross-sectional area of ​​the first and second lower flanges.

[0023] Optionally, the number and specifications of the first side connecting bolts and the second side connecting bolts, as well as the dimensions of the angle steel connectors, are determined based on strength conditions such as the net cross-sectional area of ​​the left web and the right web.

[0024] The present invention discloses the following technical effects:

[0025] All connecting components of this invention are connected to the beam body by high-strength bolts, completely avoiding on-site welding and realizing fully bolted assembly connection, which greatly improves construction speed and quality stability, and conforms to the development direction of green and efficient prefabricated buildings.

[0026] This invention directly transmits pressure or tension through the upper flange connecting plate, compensates for height differences and transmits axial force through a specially designed lower flange connector, and transmits web shear force through double angle steel connectors, forming a clear and continuous internal force transmission path, thus ensuring the overall working performance of the node under bending moment and shear force. Attached Figure Description

[0027] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0028] Figure 1 This is an axonometric view of the overall structure of the present invention;

[0029] Figure 2 This is an exploded view of the overall structure of the present invention;

[0030] Figure 3 This is a schematic diagram of the upper flange connecting plate of the present invention;

[0031] Figure 4 This is a schematic diagram of the structure of the I-beam end plate of the present invention;

[0032] Figure 5 This is a schematic diagram of the angle steel connector of the present invention;

[0033] Figure 6 This is an axonometric view of the lower flange connector of the present invention;

[0034] Figure 7 This is a top view of the lower flange connector of the present invention;

[0035] Figure 8 This is the moment-interstory drift angle hysteresis curve of the present invention;

[0036] Figure 9 This is the stress cloud diagram of the present invention when the interlayer displacement angle is 0.04.

[0037] In the diagram: 1. Rectangular steel pipe beam; 101. First upper flange; 102. First lower flange; 103. Left web; 104. Right web; 2. I-beam; 201. Second upper flange; 202. Second lower flange; 3. Upper flange connecting plate; 4. I-beam end plate; 5. Lower flange connector; 501. First horizontal steel plate; 502. Second horizontal steel plate; 503. Stiffening rib; 504. Vertical steel plate; 6. Angle steel connector; 61. First side plate; 62. Second side plate; 7. Upper connecting bolt; 8. First lower connecting bolt; 9. Second lower connecting bolt; 10. First side connecting bolt; 11. Second side connecting bolt. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Reference Figures 1 to 9 This invention provides a prefabricated splicing node for steel beams of unequal height, comprising:

[0041] The rectangular steel pipe beam 1 includes a first upper flange 101, a first lower flange 102, a left web 103, and a right web 104;

[0042] The I-beam 2 includes a second upper flange 201 and a second lower flange 202. The second upper flange 201 is at the same height as the first upper flange 101, and the second lower flange 202 has a height difference from the first lower flange 102.

[0043] The upper flange connecting plate 3 is connected to the first upper flange 101 and the second upper flange 201 by a first set of high-strength bolts;

[0044] The lower flange connector 5 is connected to the first lower flange 102 and the second lower flange 202 by a second set of high-strength bolts;

[0045] The end plate 4 of the I-beam is fixed to the end of the I-beam 2 near the rectangular steel pipe beam 1;

[0046] A pair of angle steel connectors 6 are connected to the left web plate 103, the right web plate 104 and the end plate 4 of the I-beam through a third set of high-strength bolts.

[0047] The upper flange connecting plate 3 and the lower flange connecting piece 5 ensure that the axial force in the flange caused by bending moment can be continuously transmitted. A pair of angle steel connecting pieces 6 are provided between the left web plate 103 and the right web plate 104 of the rectangular steel pipe beam 1 and the I-beam end plate 4 of the I-beam 2 to transmit shear force. All connection forms ensure the continuity of internal force transmission.

[0048] In this invention, both the rectangular steel pipe beam 1 and the I-beam 2 are fabricated in the factory, ensuring welding quality. There is no welding work on the construction site; only bolt splicing is required, which guarantees construction quality and shortens the construction period.

[0049] In one embodiment of the present invention, the first set of high-strength bolts includes a plurality of upper connecting bolts 7, which are connected between the upper flange connecting plate 3 and the first upper flange 101 and the second upper flange 201. Bolt holes are provided in the first upper flange 101 and the second upper flange 201. The upper flange connecting plate 3 is provided on the outer side, and bolt holes are provided on the upper flange connecting plate 3. The positions of the bolt holes correspond to the positions of the bolt holes in the first upper flange 101 and the second upper flange 201. The first upper flange 101, the second upper flange 201 and the upper flange connecting plate 3 are connected by the upper connecting bolts 7.

[0050] Multiple upper connecting bolts 7 are used to connect the upper flange connecting plate 3 to the first upper flange 101 and the second upper flange 201, ensuring reliable transmission of pressure or tension in the upper flange area. This design allows the upper flange connecting plate 3 to fit tightly with the first upper flange 101 and the second upper flange 201, resulting in uniform stress distribution and avoiding stress concentration, which is the basis for achieving the bending resistance of the joint.

[0051] In one embodiment of the present invention, the lower flange connector 5 includes a first horizontal steel plate 501, a second horizontal steel plate 502, a vertical steel plate 504, and a pair of stiffening ribs 503. The first horizontal steel plate 501, the vertical steel plate 504, and the second horizontal steel plate 502 are connected in sequence to form a Z-shaped structure. The stiffening ribs 503 are connected to the side of the Z-shaped structure. The vertical steel plate 504 is used to fill the height difference between the first lower flange 102 and the second lower flange 202.

[0052] The Z-shaped structure is key to adapting to the height difference of the lower flange. Vertical steel plate 504 fills the height difference space, while the first horizontal steel plate 501 and the second horizontal steel plate 502 are connected to the first lower flange 102 and the second lower flange 202, respectively. This structure not only achieves a physical connection but, more importantly, ensures that the axial force transmitted through the lower flange under bending moment can be continuously and smoothly transmitted through this connector. This is one of the core innovations in achieving equal-strength connections at the joint. The stiffening rib 503 significantly enhances the local stability and overall stiffness of the connector under complex stress conditions.

[0053] In one embodiment of the present invention, the second set of high-strength bolts includes:

[0054] Multiple first lower connecting bolts 8 are connected between the first horizontal steel plate 501 and the first lower flange 102;

[0055] Multiple second lower connecting bolts 9 are connected between the second horizontal steel plate 502 and the second lower flange 202.

[0056] The first horizontal steel plate 501 and the second horizontal steel plate 502 of the lower flange connector 5 abut against the first lower flange 102 and the second lower flange 202, respectively. Bolt holes are opened on the first horizontal steel plate 501 and the second horizontal steel plate 502, and bolt holes are opened on the first lower flange 102 and the second lower flange 202. The positions of the holes correspond to the positions of the bolt holes on the first horizontal steel plate 501 and the second horizontal steel plate 502, respectively. The first lower flange 102 and the first horizontal steel plate 501 are connected by the first lower connecting bolt 8, and the second lower flange 202 and the second horizontal steel plate 502 are connected by the second lower connecting bolt 9.

[0057] The two horizontal ends of the Z-shaped structure are connected to the corresponding lower flanges of the beam using first lower connecting bolt 8 and second lower connecting bolt 9, respectively. This separate connection design facilitates on-site installation and adjustment, ensures that the bolts on each connection surface can work effectively and jointly bear the axial force transmitted from the lower flange, further optimizing the force transmission path.

[0058] In one embodiment of the present invention, the angle steel connector 6 includes a first side plate 61 and a second side plate 62 that are perpendicular to each other. The two first side plates 61 correspond to the left web plate 103 and the right web plate 104, respectively, and the second side plate 62 corresponds to the end plate 4 of the I-beam.

[0059] It is clarified that the angle steel connector 6 adopts the structure of the first side plate 61 and the second side plate 62, which correspond to the two left web plates 103 and the right web plates 104 of the rectangular steel pipe beam 1 and the end plate 4 of the I-beam, respectively. This design allows the angle steel connector 6 to fit tightly on the plates on both sides, forming a reliable shear-resistant connection surface, effectively transferring the shear force at the end of the I-beam 2 to the left web plate 103 and the right web plate 104 of the rectangular steel pipe beam 1, thereby completing the transfer of shear force in the node area.

[0060] In one embodiment of the present invention, the third group of high-strength bolts includes:

[0061] Multiple first-side connecting bolts 10 are connected between a pair of first-side plates 61 and the left web plate 103 and the right web plate 104;

[0062] Multiple second-side connecting bolts 11 are connected between a pair of second-side plates 62 and the end plate 4 of the I-beam.

[0063] Bolt holes are made on the end plate 4 of the I-beam. Bolt holes are also made on the left web 103 and the right web 104. The left web 103 and the right web 104 are perpendicular to the end plate 4 of the I-beam. Two angle steel connectors 6 are provided between them. The first side plate 61 and the second side plate 62 of the angle steel connectors 6 abut against the left web 103, the right web 104 and the end plate 4 of the I-beam, respectively. Bolt holes are made on the first side plate 61 and the second side plate 62. The positions of the bolt holes correspond to the positions of the bolt holes on the left web 103 and the right web 104 and the end plate 4 of the I-beam, respectively. The first side plate 61 and the second side plate 62 are connected to the left web 103 and the right web 104 and the end plate 4 of the I-beam by the first side connecting bolt 10 and the second side connecting bolt 11, respectively.

[0064] The first side connecting bolt 10 and the second side connecting bolt 11 are used to connect the angle steel connector 6 to the left web plate 103 and the right web plate 104, and the angle steel connector 6 to the end plate 4 of the I-beam. This clear bolt grouping makes the shear force transmission path clear and the construction sequence clear.

[0065] In one embodiment of the present invention, the stiffening rib 503 is rhomboid in shape.

[0066] The rhomboid stiffener 503 provides the necessary stiffness while having better stress distribution characteristics, which can more effectively suppress the local buckling of the vertical steel plate 504 in the Z-shaped lower flange connector 5, improve the fatigue performance and energy dissipation capacity of the connector under cyclic loading, and is an important detail for optimizing the ductility of the joint.

[0067] In one embodiment of the present invention, the number and specifications of the upper connecting bolts 7 and the size of the upper flange connecting plate 3 are determined based on the equal strength condition of the net cross-sectional area of ​​the first upper flange 101 and the second upper flange 201.

[0068] In one embodiment of the present invention, the quantity and specifications of the first lower connecting bolt 8 and the second lower connecting bolt 9, as well as the dimensions of the first horizontal steel plate 501, the second horizontal steel plate 502, the vertical steel plate 504 and the stiffening rib 503, are determined based on strength conditions such as the net cross-sectional area of ​​the first lower flange 102 and the second lower flange 202.

[0069] In one embodiment of the present invention, the number and specifications of the first side connecting bolts 10 and the second side connecting bolts 11, as well as the dimensions of the angle steel connector 6, are determined based on strength conditions such as the net cross-sectional area of ​​the left web plate 103 and the right web plate 104.

[0070] Furthermore, net cross-sectional area and other strengths are important concepts in structural engineering, mainly involving simplified methods for calculating the cross-sectional strength of structural members. The specific calculation methods are existing technologies and will not be elaborated here.

[0071] As attached Figure 8-9 As shown, a detailed finite element analysis was performed on this embodiment to evaluate the seismic performance of the splicing node. The finite element model has approximately 180,000 elements, all modeled using solid elements. Contact elements were established between the upper flange connecting plate 3 and the first upper flange 101 and the second upper flange 201, between the angle steel connector 6 and the I-beam end plate 4, between the angle steel connector 6 and the left web 103 and the right web 104, between the lower flange connector 5 and the first lower flange 102 and the second lower flange 202, between the bolt and the hole wall, and between the nut and the plate. The calculation results are shown in the figure. Figure 9 It can be seen that the moment-inter-story drift hysteresis curve is a full spindle shape without pinching or strength degradation, indicating that the node has good energy dissipation capacity. The stress cloud diagram shows that when the inter-story drift angle reaches 0.04, no local buckling occurs in the beam flange and web. The upper flange connecting plate 3, lower flange connecting piece 5, and angle steel connecting piece 6 all reach the yield state and exhibit local out-of-plane deformation. The connecting pieces effectively protect the main beam members in the node from damage. Under a major earthquake, this spliced ​​node exhibits good ductility.

[0072] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0073] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A prefabricated splicing node for steel beams of unequal height, characterized in that, include: The rectangular steel pipe beam (1) includes a first upper flange (101), a first lower flange (102), a left web (103) and a right web (104); The I-beam (2) includes a second upper flange (201) and a second lower flange (202). The second upper flange (201) is at the same height as the first upper flange (101), and the second lower flange (202) has a height difference with the first lower flange (102). The upper flange connecting plate (3) is connected to the first upper flange (101) and the second upper flange (201) by a first set of high-strength bolts; The lower flange connector (5) is connected to the first lower flange (102) and the second lower flange (202) by a second set of high-strength bolts; The end plate (4) of the I-beam is fixed to the end of the I-beam (2) near the rectangular steel pipe beam (1); A pair of angle steel connectors (6) are connected to the left web plate (103), the right web plate (104) and the end plate (4) of the I-beam by a third set of high-strength bolts.

2. The prefabricated splicing node for unequal-height steel beams according to claim 1, characterized in that, The first set of high-strength bolts includes multiple upper connecting bolts (7), which are connected between the upper flange connecting plate (3) and the first upper flange (101) and the second upper flange (201).

3. The prefabricated splicing node for unequal-height steel beams according to claim 1, characterized in that, The lower flange connector (5) includes a first horizontal steel plate (501), a second horizontal steel plate (502), a vertical steel plate (504), and a pair of stiffening ribs (503). The first horizontal steel plate (501), the vertical steel plate (504), and the second horizontal steel plate (502) are connected in sequence to form a Z-shaped structure. The stiffening ribs (503) are connected to the side of the Z-shaped structure. The vertical steel plate (504) is used to fill the height difference between the first lower flange (102) and the second lower flange (202).

4. The prefabricated splicing node for unequal-height steel beams according to claim 3, characterized in that, The second group of high-strength bolts includes: Multiple first lower connecting bolts (8) are connected between the first horizontal steel plate (501) and the first lower flange (102); Multiple second lower connecting bolts (9) are connected between the second horizontal steel plate (502) and the second lower flange (202).

5. The prefabricated splicing node for unequal-height steel beams according to claim 1, characterized in that, The angle steel connector (6) includes a first side plate (61) and a second side plate (62) that are perpendicular to each other. The two first side plates (61) correspond to the left web plate (103) and the right web plate (104) respectively, and the second side plate (62) corresponds to the end plate (4) of the I-beam.

6. The prefabricated splicing node for unequal-height steel beams according to claim 5, characterized in that, The third group of high-strength bolts includes: Multiple first-side connecting bolts (10) are connected between a pair of first-side plates (61) and the left web plate (103) and the right web plate (104); Multiple second-side connecting bolts (11) are connected between a pair of second-side plates (62) and the end plates (4) of the I-beam.

7. The prefabricated splicing node for unequal-height steel beams according to claim 3, characterized in that, The stiffening rib (503) is rhomboid in shape.

8. The prefabricated splicing node for unequal-height steel beams according to claim 2, characterized in that, The number and specifications of the upper connecting bolts (7) and the size of the upper flange connecting plate (3) are determined based on the equal strength condition of the net cross-sectional area of ​​the first upper flange (101) and the second upper flange (201).

9. A prefabricated splicing node for unequal-height steel beams according to claim 4, characterized in that, The quantity and specifications of the first lower connecting bolt (8) and the second lower connecting bolt (9), as well as the dimensions of the first horizontal steel plate (501), the second horizontal steel plate (502), the vertical steel plate (504), and the stiffening rib (503), are determined based on strength conditions such as the net cross-sectional area of ​​the first lower flange (102) and the second lower flange (202).

10. A prefabricated splicing node for unequal-height steel beams according to claim 6, characterized in that, The quantity and specifications of the first side connecting bolt (10) and the second side connecting bolt (11), as well as the size of the angle steel connector (6), are determined based on the strength conditions such as the net cross-sectional area of ​​the left web plate (103) and the right web plate (104).

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