Hyperbolic paraboloid thin plate dense ribbed plate element for steel bridge and manufacturing method thereof

Abstract

The present invention relates to a steel bridge hyperbolic paraboloid thin plate dense rib plate unit and its manufacturing method, which includes structural digital modeling → part lofting → CNC blanking → automatic marking → cold pressing primary forming → tooling production → hot straightening secondary forming → assembly of plate unit stiffeners → plate unit welding → structural welding inspection → deformation correction → assembly and welding of shear studs → assembly of steel bars. Advantages: First, it solves the problem of expressing hyperbolic paraboloid structural information of steel bridges, achieving effective transmission of construction information; second, it solves the problem of forming hyperbolic paraboloid curved panels of steel bridges, and its forming accuracy meets the relevant requirements of design and standards; third, it meets the project's hyperbolic paraboloid panel unit manufacturing task requirements, ensuring the project construction quality and progress; fourth, it improves the level of processing and manufacturing technology for complex curved structures of steel bridges, promoting the continuous development of steel bridge manufacturing technology.

Description

Technical Field

[0001] The present invention relates to a tower column portion outer wall plate unit, the cross-section of which is an R1m or R3m circular arc curve, the upper and lower arcs are not concentric, the radius is the same, and the arc length is different, and the plate unit is vertically an arbitrary curve, forming a steel bridge hyperbolic paraboloid thin plate dense rib plate unit with a structure similar to a saddle surface or a hyperbolic paraboloid, and a manufacturing method thereof, belonging to the field of super-large steel-concrete bridge manufacturing. Background Art

[0002] Steel bridges built in China are primarily linear, with two-dimensional curved structures (curved in one direction) being a secondary feature. However, with the improvement of my country's steel bridge construction capabilities and the people's growing material and cultural needs, steel bridges are becoming diversified, with three-dimensional curved structures (spatial curved structures) gradually becoming a highlight of steel bridge construction. The twisted surface structures in three-dimensional curved structures can be approximately unfolded, and the bottleneck in their processing and manufacturing technology has been overcome. However, for hyperbolic paraboloid structures, the plate unit manufacturing technology remains a technical challenge. If traditional two-dimensional curved plate forming methods are used, it is difficult to accurately express part dimensions. Cold pressing and roll bending can only be performed in one direction, which cannot meet the requirements of the bidirectional curve line shape of the hyperbolic paraboloid. The multi-point top pressing scheme using twisted linear plates is difficult to achieve top pressing control over a long stroke due to the small structural curvature and large line shape variations, and the line shape accuracy cannot be guaranteed. Summary of the Invention

[0003] Design purpose: To avoid the shortcomings of the background technology, a tower column outer wall plate unit is designed with a cross-section of R1m and R3m arc curves. The upper and lower arcs are not concentric, the radius is the same, and the arc lengths are different. The plate unit is an arbitrary curve vertically, forming a steel bridge hyperbolic paraboloid thin plate dense rib plate unit and its manufacturing method similar to a saddle surface or hyperbolic paraboloid structure.

[0004] Design: To achieve the above design objectives, the present invention addresses the linear processing issues of the hyperbolic parabolic panel unit structure of steel bridges. Combining the steel bridge manufacturing process, the present invention employs digital models for part layout, CNC precision cutting, laser automatic marking, cold pressing in the main curve direction, tooling and thermal correction to achieve hyperbolic surface forming, tightening and assembling horizontal and vertical ribs, welding with a low-energy-line process, and assembling horizontal and vertical reinforcements.

[0005] The above-mentioned hyperbolic parabolic panel unit manufacturing plan for steel bridges uses existing production equipment and has developed a series of construction measures for hyperbolic parabolic panel unit structure layout, parts processing, surface forming, plate unit welding and pre-welded parts installation. From structural layout and processing to the completion of plate unit production, corresponding measures are in place to ensure process quality, which can effectively meet the manufacturing accuracy requirements of hyperbolic parabolic panel units. This method is convenient, easy to use, and highly practical, and deserves to be widely promoted in the manufacturing of such structures.

[0006] Structural solution: In view of the structural characteristics of the hyperbolic parabolic panel unit of steel bridges, the following manufacturing process is proposed: digital modeling of the structure → part lofting → CNC blanking → automatic marking → cold pressing one-step forming → tooling production → hot straightening secondary forming → assembly of panel unit stiffeners → panel unit welding → structural welding inspection → deformation correction → assembly of shear studs → assembly of steel bars.

[0007] BIM digital modeling was performed based on the design structure, decomposing the hyperbolic parabola line shape into approximate lines in two directions. The sheet metal unfolding function of the software was used to achieve approximate unfolding of the hyperbolic parabola part and obtain the part's outline dimensions. CNC precision cutting equipment was used for flame cutting, and bending lines were arranged according to the cold-bending forming process requirements. A laser automatic marking machine was used to mark the bending lines of the part. A dedicated cold-pressing machine was used to pre-bend the part in one direction along the bending lines. The part was then thermally straightened and formed on a dedicated mold for the hyperbolic parabola panel unit, ensuring that the line shape closely matched the mold support before being fixed. The curved plate ribs produced by CNC precision cutting were assembled, ensuring that the ribs and the curved panel were closely aligned. Low-energy CO2 gas shielded welding was performed symmetrically. The welding deformation was constrained using the Magu method during the welding process. After welding, the structural line shape and weld quality were inspected, and local deformation caused by welding was corrected using thermal straightening. Shear pin position lines were arranged as required, and shear pins were welded on the plate unit. Pre-processed steel bars were inserted into the horizontal and vertical ribs and temporarily secured using positioning fixtures.

[0008] Technical solution: A method for manufacturing hyperbolic paraboloid thin plate dense rib plate units for steel bridges, including structural digital modeling → part lofting → CNC blanking → automatic marking → cold pressing one-step forming → tooling production → hot straightening secondary forming → assembly of plate unit stiffeners → plate unit welding → structural welding inspection → deformation correction → assembly of shear studs → assembly of steel bars.

[0009] Compared with the background technology, the present invention, firstly, solves the problem of expressing the hyperbolic paraboloid structure information of steel bridges and realizes the effective transmission of construction information; secondly, solves the problem of forming the hyperbolic paraboloid curved panels of steel bridges, and its forming accuracy meets the relevant requirements of design and standards; thirdly, realizes the manufacturing task requirements of the project's hyperbolic paraboloid panel units and ensures the quality and progress of the project construction; fourthly, improves the technical level of processing and manufacturing complex curved structures of steel bridges and promotes the continuous development of steel bridge manufacturing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the hyperbolic parabola panel unit structure.

[0011] Figure 2 It is a schematic diagram of the manufacturing information expression of the hyperbolic parabola.

[0012] Figure 3 yes Figure 1 Schematic diagram of the AA section view.

[0013] Figure 4 It is a schematic diagram of the cross section of the tire mold for making hyperbolic parabolic panels.

[0014] Figure 5 It is a side view of the tire shape for making hyperbolic parabolic panels.

[0015] Figure 6 It is a schematic diagram of the assembly sequence of the hyperbolic parabola panel unit.

[0016] Figure 7 The following are pictures of hyperbolic parabola panel units and steel bar installation examples. They are for the purpose of illustrating the present invention and may be deleted if they do not meet the requirements. DETAILED DESCRIPTION

[0017] Example 1: Attached Figure 1-7 A method for manufacturing hyperbolic paraboloid thin plate dense rib plate units for steel bridges, comprising structural digital modeling → part lofting → CNC blanking → automatic marking → cold pressing for primary forming → tooling fabrication → hot straightening for secondary forming → assembly of plate units and stiffening ribs → plate unit welding → structural welding inspection → deformation correction → assembly of shear studs → assembly of steel bars.

[0018] The specific production plan is as follows: BIM digital modeling is carried out according to the design structure, the hyperbolic paraboloid line shape is decomposed into approximate lines in two directions, and the sheet metal unfolding function of the software is used to realize the approximate unfolding of the hyperbolic paraboloid part to obtain the outline size of the part; CNC precision cutting equipment is used to flame cut the material, and the bending lines are arranged according to the requirements of the cold bending forming process. The bending lines of the parts are arranged using a laser automatic marking machine, and the parts are pre-bent in one direction according to the bending lines using a special cold pressing machine, and then the parts are pre-bent on the special tire mold of the hyperbolic parabola panel unit. Perform thermal correction and forming to make its linear shape fit closely with the tire support and then fix it; assemble the curved plate ribs made by CNC precision cutting to make the plate ribs close to the curved plate, use CO2 gas shielded welding with small linear energy to perform symmetrical welding, use the Magu method to constrain welding deformation during welding, and conduct structural linear shape and weld quality inspection after welding. Use thermal correction to repair the local deformation caused by welding; arrange the shear nail position line as required, weld the shear nails on the plate unit, insert the processed steel bars into the horizontal and vertical ribs and temporarily fix them with positioning tooling.

[0019] Process method: Based on the characteristics of the hyperbolic parabolic panel unit of steel bridges and combined with the processing and manufacturing process methods, the key points of the construction technology of the hyperbolic parabolic panel unit are as follows:

[0020] (1) Key points for expressing manufacturing information of hyperbolic paraboloids: The hyperbolic paraboloid structure has a special linear shape. It is difficult to express the linear features using traditional engineering drawings, and it is impossible to guide on-site construction operations. In order to accurately and effectively display the structural information of the hyperbolic paraboloid, CATIA 3D modeling software is used for structural information modeling. The hyperbolic paraboloid linear shape is projected onto two orthogonal surfaces through a digital model, and the overall linear shape accuracy is achieved by controlling the linear shape in two directions. The contour dimensions of the hyperbolic paraboloid parts are approximately lofted through the sheet metal unfolding function of the 3D software and directly converted into a part CNC blanking compilation program. The plate ribs of the hyperbolic paraboloid panel are directly compiled into a blanking program by lofting the curve contour dimensions of the model. In order to control the forming construction of the hyperbolic paraboloid, mechanical bending lines and assembly reference lines are laid out on the curved panel and directly converted into the unfolded hyperbolic paraboloid parts.

[0021] (2) Processing and forming requirements for hyperbolic paraboloid parts: According to the digital model, the size of the parts to be laid out is displayed. Combined with the number of structural plate ribs and welding requirements, process allowances in all directions are reserved. High-precision CNC blanking machines are used for flame cutting, and contour cutting machines are used for peripheral welding groove processing. According to the bending lines and assembly reference line information laid out, laser CNC marking machines are used on a dedicated platform to lay out the reference lines. The reference lines are marked on both sides as the basis for subsequent plate unit assembly. According to the linear characteristics of the hyperbolic parabola, the arc variable cross-section curve with a small curvature radius is first processed. Cold bending is mainly performed using cold forming equipment. During the cold bending process, the cold pressing curve line shape is strictly controlled, and a special template is used for uninterrupted testing to ensure that the circular curve is smooth and the curvature radius of the upper and lower ends is correct. According to the linear shape of each curved panel, an adjustable curved surface forming mold is designed (the mold is equipped with a two-way pre-deformation). The hyperbolic parabolic panel formed in one step is put in place, and the heat correction method is used to form the curve in the normal direction of the arc. Finally, the hyperbolic parabolic panel reaches the linear shape of the mold and is consolidated with temporary horse-fixing measures.

[0022] (3) Requirements for the welding process of hyperbolic parabola panel units: Due to the influence of the hyperbolic parabola line shape, the previous project assembly sequence (welding the vertical ribs first, then the transverse ribs) will cause the vertical and transverse ribs to interfere with each other and cannot be assembled. In order to control the assembly accuracy and constrain the welding deformation, the transverse ribs are first assembled along the line, and then the vertical ribs are inserted from the end to make each plate rib close to the curved plate, and the transverse and vertical ribs are tightly pressed together; first, the connecting welds of the curved plate and the transverse ribs are welded in a central and symmetrical manner as the internal support structure of the main curve line shape, and then the connecting welds of the curved plate and the vertical ribs are welded in a central and symmetrical manner. The welding adopts the CO2 gas shielded welding process with low line energy. During the welding process, pay attention to controlling the welding parameters to minimize welding deformation and avoid warping deformation. After the welding is completed, the rigid constraints are released, and the line shape and welds are inspected as a whole. The local angular deformation of the welding is corrected by thermal correction, and the vertical and transverse reference lines of the plate unit are corrected as the reference for later construction.

[0023] (4) Key points for welding shear nails and reinforcement bars of hyperbolic parabolic panel units: Shear nails are densely distributed on the hyperbolic parabolic panel. The shear nail positions are arranged according to the reference line. Arc welding is used for welding shear nails. Shear nails in the joint area of ​​the panel unit are welded after the joint welding is completed. Circumferential and vertical reinforcements are connected with Class I threaded joints and installed by pulling, pushing, etc. In order to ensure the positioning of the vertical reinforcement in the hole without affecting the precise connection of the joint during the bridge installation, a special tool for positioning reinforcement is specially designed to ensure accurate positioning of the reinforcement and safe construction. According to the curve line shape, the circumferential reinforcement of the panel unit is curved. Considering the structure of the reinforcement anchor end, it is inserted from the threaded end to the hole group of the vertical rib of the panel unit in sequence, and a guide system is used to assist to ensure the speed of reinforcement installation.

[0024] The fabrication method for hyperbolic paraboloid thin-plate dense-ribbed slab elements is a comprehensive set of technologies developed based on previous experience in bridge steel structure manufacturing and a series of process measures tailored to the specific project. This technology was developed through trial production of test pieces, process analysis, and result testing and evaluation. During project implementation, product quality has steadily improved through continuous process optimization, precise control of mold accuracy, and enhanced overall technical expertise, ensuring the manufacturing efficiency and quality of these hyperbolic paraboloid thin-plate dense-ribbed slab elements.

[0025] The method for manufacturing hyperbolic paraboloid thin plate dense rib plate units for steel bridges is suitable for the production of complex linear plate units of hyperbolic thin plates. It can realize the streamlined construction of plate unit production and ensure the linear accuracy of the curved plate. The adopted process method is mature, stable and highly adaptable. It is a new breakthrough in the manufacturing technology of hyperbolic paraboloid thin plate dense rib plate units and is worthy of reference for similar projects. Its process method has promotion value.

[0026] Example 2: Refer to the attached Figure 1-7 A hyperbolic paraboloid thin-plate dense-ribbed slab unit for a steel bridge. Multiple transverse ribs 2 of the wall panel closely mate with the curved wall panel 4. Multiple vertical ribs 1 of the wall panel closely mate with the curved wall panel 4. The cross-sectional circular curve formed by these elements has equal diameters in all sections 3, and unequal longitudinal sagittal heights in all sections 6. Multiple steel bars 5 are inserted between the multiple transverse ribs 2, either from top to bottom or from bottom to top.

[0027] It should be understood that although the above embodiments provide a relatively detailed textual description of the design ideas of the present invention, these textual descriptions are only simple textual descriptions of the design ideas of the present invention, rather than limitations on the design ideas of the present invention. Any combination, addition or modification that does not exceed the design ideas of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for manufacturing a hyperbolic paraboloid thin plate dense rib unit for a steel bridge, characterized by: Structural digital modeling → part lofting → CNC blanking → automatic marking → cold pressing one-step forming → tooling production → hot straightening secondary forming → assembly of plate unit stiffeners → plate unit welding → structural welding inspection → deformation repair → assembly and welding of shear nails → assembly of steel bars; BIM digital modeling is carried out according to the design structure, and the hyperbolic paraboloid line shape is decomposed into approximate lines in two directions. The sheet metal unfolding function of the software is used to realize the approximate unfolding of the hyperbolic paraboloid parts and obtain the outline size of the parts; CNC precision cutting equipment is used to flame cut the materials, and the bending lines are arranged according to the requirements of the cold bending forming process. The laser automatic marking machine is used to mark the bending lines of the parts, and the bending lines are arranged according to the bending lines. Use a special cold pressing machine to pre-bend the curve of the parts in one direction, and then perform heat correction and forming on a special tire mold for the hyperbolic parabola panel unit so that its linear shape is closely attached to the tire mold support and then fixed; assemble the curved plate ribs made by CNC precision cutting so that the plate ribs are close to the curved panel, and use CO2 gas shielded welding with small linear energy to perform welding symmetrically. During the welding process, the Magu method is used to constrain the welding deformation. After welding, the structural linear shape and weld quality are inspected, and the local deformation caused by welding is repaired by heat correction; the shear nail position line is arranged as required, the shear nails on the plate unit are welded, the processed steel bars are inserted into the horizontal and vertical ribs and temporarily fixed with positioning tooling.

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