Steel truss beam super-long T-shaped beam manufacturing precision control method

Abstract

The application discloses a kind of steel truss beam super-long T type beam manufacturing precision control method, comprising the following steps: making block scheme, large crossbeam is divided into multiple small crossbeam, control single small crossbeam length does not exceed 9m, and butt joint groove is set in the web and flange plate joint position of small crossbeam;Modeling lofting, web and flange plate are sequentially exported, and process addition is set in the bolt hole side of small crossbeam, while the width addition of U rib groove is set;With baseline as reference assembly small crossbeam web and flange plate, clear assembly precision control target;Design large crossbeam overall assembly scheme, optimize structure welding sequence, make pre-arch process parameter, finally realize precision control target.The application is not affected by the length of steel plate rolling capacity, can adapt to the machining precision control of orthogonal anisotropic plate in steel structure bridge, and the general-purpose of blanking, tailor-welding and other processing equipment is used for various steel structure processing plant, with high precision after manufacturing, reduce a large number of repair work, can obviously improve construction efficiency.

Description

Technical Field

[0001] This invention relates to a method for controlling the manufacturing precision of T-shaped crossbeams, and more particularly to a method for controlling the manufacturing precision of ultra-long T-shaped crossbeams for steel trusses. Background Technology

[0002] Currently, many operating highways are approaching traffic saturation, and frequent congestion is even occurring. Therefore, to meet the ever-increasing traffic demands, highway reconstruction and expansion have become a crucial development need in highway transportation construction. Steel bridge structures, due to their relatively light weight, high material strength, and convenient construction, are widely used in bridges of various spans. In particular, steel truss bridges, composed of truss members, are characterized by small member dimensions, convenient transportation, rapid erection, minimal impact on navigation, and better stress distribution. Therefore, steel structure bridges are gradually being promoted and applied in highway reconstruction and expansion projects, and there is a significant demand for large-span simply supported steel truss bridges with excellent mechanical properties, convenient erection, strong seismic resistance, and good driving comfort.

[0003] With the continuous development of steel truss bridges, from two-lane to four-lane expansions, the bridge deck width has also increased significantly. Due to the special geographical location and the size limitations imposed by road transport, bridge deck panels and crossbeams need to be shipped separately to the bridge site. Ensuring the precision of the U-ribs in the bridge deck panels and the grooves in the crossbeams during the erection process has brought significant challenges to the current technology. Currently, large steel truss girders are transported by ship, and can be fabricated in factories as large segments or bridge deck blocks for overall installation on-site. In these two solutions, since the crossbeams and bridge deck panels are pre-assembled in the factory, there is no issue of the crossbeams matching the bridge deck panels with precision. However, for the increasing number of small- and medium-span steel truss girders in highway reconstruction and expansion projects, the size limitations of road transport make the process of fabricating bridge deck blocks unsuitable. Furthermore, the larger the size, the greater the transportation risk and the higher the corresponding costs. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to propose a method for controlling the manufacturing precision of ultra-long T-shaped crossbeams of steel trusses, which is not affected by the length of the steel plate and has high manufacturing precision.

[0005] Technical solution: This invention includes the following steps:

[0006] S1. Develop a segmentation plan to divide the main beam into multiple smaller beams, control the length of a single smaller beam to not exceed 9m, and set a butt bevel at the joint of the web and flange of the smaller beam.

[0007] S2. Modeling and layout: The web and flange plates of the small crossbeam are laid out in sequence, and process allowances are set on the bolt hole side of the small crossbeam. At the same time, the width allowance of the U-rib slot is set.

[0008] S3. Assemble the web and flange of the small crossbeam based on the baseline, and position and assemble the stiffening ribs based on the reference end and the inner skin of the flange, and clarify the assembly accuracy control target.

[0009] S4. Assemble the main crossbeam as a whole, optimize the structural welding sequence, formulate pre-arching process parameters, and control the precision of the bolt hole group.

[0010] The main beam includes a web and flanges. The flanges are located at the bottom of the web. The top of the web has multiple U-rib slots spaced apart. Bolt hole groups are provided on both sides of the web. Stiffening ribs are provided on the sides of the web.

[0011] During modeling, the main beam is simultaneously divided into multiple segments according to the block segmentation scheme in the model.

[0012] The web of the small crossbeam is cut out using a CNC blanking device, and precise lines are drawn on the web to mark the vertical baseline and bevel cutting line. The bevel is then cut using a semi-automatic trolley.

[0013] The flange plate of the small crossbeam is cut out by a gantry cutting machine and the bevel is cut by a semi-automatic trolley.

[0014] The assembly of the small crossbeam web and flange plate based on the baseline is specifically as follows: on the jig, with the longitudinal centerline of the flange plate as a reference, the web and flange plate are aligned and positioned to assemble the small crossbeam T-shape, and the bevel of the bottom plate of the flange plate faces the non-crossbeam side during assembly.

[0015] The assembly accuracy control targets are specifically: the transverse flatness of the web plate is ≤2.0mm, the longitudinal flatness is ≤3.0mm, the verticality of the stiffening ribs is ≤1.0mm, and the lateral bending is ≤3.0mm.

[0016] The pre-arching process parameters are as follows: lay small crossbeams T-shaped on the jig and assemble them with the baseline as the reference; during assembly, the middle crossbeam is pre-lifted 15-18mm towards the U-rib groove side, the ends of the two small crossbeams remain unchanged, and the docking ends are finely adjusted to ensure that the misalignment of the docking flange edges is ≤0.5mm.

[0017] The welding sequence is as follows: first, weld the butt joint of the web of the beam symmetrically, then weld the butt joint of the flange plate symmetrically. After welding, correct the flatness of the web and the verticality of the stiffeners. The horizontal flatness of the web is ≤1.0mm / m, and the verticality of the stiffeners is ≤1.0mm.

[0018] The precision control of the bolt hole group is specifically as follows: taking the horizontal baseline and vertical baseline as reference, set the upper opening process allowance of the bolt hole group on both sides of the crossbeam, and control the lower opening according to the design size without setting the process allowance. Draw the drilling alignment line of the web plate, and simultaneously draw the matching tangent line of the two ends of the crossbeam web plate. Cut the two ends of the crossbeam according to the matching tangent line, grind and trim the flame-cut parts, and finally use a magnetic drill to accurately drill the holes using the template.

[0019] Beneficial effects: This invention is not affected by the steel mill's steel plate length rolling capacity, and can adapt to the processing accuracy control of orthogonal irregular plates in steel structure bridges. The processing equipment such as blanking and welding of this invention is universal and can be used in various steel structure processing plants. The finished product of this invention has high precision, reduces a lot of rework, and can significantly improve construction efficiency. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the beam structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the beam segmentation of the present invention;

[0022] Figure 3 This is a diagram showing the cutting process for the web of the small crossbeam after the increase in quantity.

[0023] Figure 4 This is a detailed drawing of the U-rib groove blanking process.

[0024] Figure 5 This is a schematic diagram of the small crossbeam assembly;

[0025] Figure 6 This is a schematic diagram of marking and drilling. Detailed Implementation

[0026] The invention will now be further described with reference to the accompanying drawings.

[0027] The method for controlling the manufacturing precision of ultra-long T-shaped crossbeams of steel trusses of the present invention includes the following steps:

[0028] S1. A segmentation plan was developed. To ensure optimal accuracy of the CNC cutting equipment, based on past experience in controlling cutting accuracy, the main beam was divided into multiple smaller beams. The length of each smaller beam was controlled to not exceed 9m, and bevel joints were installed at the joints between the web and flange of the smaller beams. The main beam includes a web 1 and flanges 2. Flanges 2 are located at the bottom of the web 1. The top of the web 1 has multiple U-rib slots 5 spaced apart. Bolt hole groups 4 are provided on both sides of the web 1, and stiffening ribs 3 are provided on the sides of the web 1.

[0029] S2. A 1:1 scale model is created using TEKLA modeling software. The main beam is divided into multiple segments according to the block design in the model. The web blanking file of the beam is exported from TEKLA. Process allowances are set on the bolt hole side of the small beam. At the same time, the width allowance of the U-rib groove on the beam is set. Then, the web of the small beam is accurately cut out using CNC blanking equipment. The vertical baseline and bevel cutting line of the web are accurately drawn on the web. The bevel is cut out using a semi-automatic trolley. The flange plate is accurately cut out using a gantry cutting machine. The bevel is cut out using a semi-automatic trolley.

[0030] S3. Assemble the web and flange plates of the small crossbeam using the baseline as a reference, clearly defining the assembly accuracy control targets. On the jig, using the longitudinal centerline of the flange plate as a reference, align the baselines of the web and flange plates to position and assemble the small crossbeam T-shape. During assembly, ensure that the bevel of the flange plate bottom plate faces the non-crossbeam side. Position and assemble the stiffening ribs using the reference end and the inner skin of the flange plate as references. After verifying that the assembly dimensions are correct, proceed with welding and finishing, focusing on controlling the transverse flatness of the web to ≤2.0mm, the longitudinal flatness to ≤3.0mm, the perpendicularity of the stiffening ribs to ≤1.0mm, and the lateral bending to ≤3.0mm.

[0031] S4. Lay the small crossbeam T-shaped flat on the jig and assemble it with the baseline as the reference. During assembly, the middle small crossbeam should be pre-lifted 15-18mm towards the U-rib groove side, while the ends of the two small crossbeams should remain unchanged. Fine-tune the butt joint ends to ensure that the misalignment of the butt flange plates is ≤0.5mm. After verifying that the assembly dimensions are correct, proceed with welding. During welding, strictly follow the welding sequence: first weld the butt joint of the crossbeam web symmetrically, then weld the butt joint of the flange plates symmetrically. After welding, correct the flatness of the web and the verticality of the stiffeners. The horizontal flatness of the web should be ≤1.0mm / m, and the verticality of the stiffeners should be ≤1.0mm. Using the horizontal and vertical baselines as references, set the upper process allowance for the bolt hole groups on both sides of the crossbeam, and control the lower opening according to the design dimensions without setting a process allowance. Draw the drilling alignment line of the web and simultaneously draw the tangent lines at both ends of the crossbeam web. Cut the two ends of the crossbeam according to the cutting line, grind and trim the flame-cut parts, and finally use a magnetic drill to precisely drill holes in the template.

[0032] Example

[0033] The method for controlling the fabrication precision of ultra-long T-shaped crossbeams of steel trusses in this embodiment includes the following steps:

[0034] Step 1. Develop a segmentation plan. To ensure optimal accuracy of the CNC cutting equipment, based on past experience in cutting accuracy control, the main beam is divided into 3 smaller beams. See details of the segmentation. Figure 2 The length of each small crossbeam is controlled to be approximately 8 meters, and a butt bevel is installed at the joint between the web and flange of the small crossbeam. For example... Figure 1 As shown, the main crossbeam includes a web 1 and flanges 2. The flanges 2 are located at the bottom of the web 1. Multiple U-shaped rib slots 5 are spaced apart at the top of the web 1. Bolt hole groups 4 are located on both sides of the web 1, and stiffening ribs 3 are provided on the sides of the web 1. The main crossbeam is divided into three smaller crossbeams, including a first smaller crossbeam 11, a second smaller crossbeam 12, and a third smaller crossbeam 13, as shown... Figure 5 As shown.

[0035] Step 2. Create a 1:1 scale model using TEKLA modeling software. Simultaneously, divide the main beam into 3 segments according to the block design in the model. Export the beam web blanking file from TEKLA and set a +10mm process allowance on the bolt hole side of the smaller beams. Figure 3To set up the web plate blanking procedure after the additional material is added, and at the same time, an additional 4mm width of the U-rib groove on the crossbeam is set, such as... Figure 4 As shown, the web of the small crossbeam is then precisely cut out using a CNC cutting machine, and lines are precisely drawn on the web to mark the vertical baseline and bevel cutting line. The bevel is then cut using a semi-automatic trolley. The flange plate is then precisely cut out using a gantry cutting machine, and the bevel is cut using a semi-automatic trolley.

[0036] Step 3. Assemble the web and flange plates of the small crossbeam using the baseline as a reference, clearly defining the assembly accuracy control targets. On the jig, using the longitudinal centerline of the flange plate as a reference, align and position the T-shaped small crossbeam with the baselines of the web and flange plates, ensuring that the bevel of the flange plate bottom plate faces the non-crossbeam side during assembly. Position and assemble the stiffening ribs using the reference end and the inner skin of the flange plate as references. After verifying that the assembly dimensions are correct, proceed with welding and finishing, focusing on controlling the transverse flatness of the web to ≤2.0mm, the longitudinal flatness to ≤3.0mm, the perpendicularity of the stiffening ribs to ≤1.0mm, and the lateral bend to ≤3.0mm.

[0037] Step 4. Lay three small T-shaped crossbeams flat on the jig, according to... Figure 5 Assemble the beams using the baseline as a reference. During assembly, the second small crossbeam 12 is pre-lifted 15mm towards the U-rib groove side. The first small crossbeam 11 and the third small crossbeam 13 maintain their end positions. Fine-tune the butt joint ends to ensure that the misalignment of the butt flange plate edges is ≤0.5mm. After verifying that the assembly dimensions are correct, proceed with welding. During welding, strictly follow the welding sequence: first weld the butt joint of the crossbeam web symmetrically, then weld the butt joint of the flange plate symmetrically. After welding, correct the flatness of the web and the verticality of the stiffeners. The horizontal flatness of the web should be ≤1.0mm / m, and the verticality of the stiffeners should be ≤1.0mm. Using the horizontal baseline m and the vertical baseline n as references, set the upper edge of the bolt hole group on both sides of the crossbeam with additional process allowance, and control the lower edge according to the design dimensions without setting any process allowance. See details. Figure 6 Draw the drilling lines for the web plate, and simultaneously draw the tangent lines for both ends of the crossbeam web plate. Cut the crossbeam ends according to the tangent lines, grind and trim the flame-cut areas, and finally use a magnetic drill to precisely drill holes using a template.

Claims

1. A method for controlling the manufacturing precision of ultra-long T-shaped crossbeams in steel trusses, characterized in that, Includes the following steps: S1. Formulate a segmentation scheme to divide the large crossbeam into multiple small crossbeams, control the length of a single small crossbeam to not exceed 9m, and set a butt bevel at the joint of the web plate and flange plate of the small crossbeam. The large crossbeam includes a web plate and a flange plate. The flange plate is set at the bottom of the web plate. Multiple U-rib slots are spaced apart at the top of the web plate. Bolt hole groups are set on both sides of the web plate. Stiffening ribs are set on the side of the web plate. S2. Modeling and layout: The web and flange plates of the small crossbeam are laid out in sequence, and process allowances are set on the bolt hole side of the small crossbeam. At the same time, the width allowance of the U-rib slot is set. S3. Assemble the web and flange of the small crossbeam based on the baseline, and position and assemble the stiffening ribs based on the reference end and the inner skin of the flange, and clarify the assembly accuracy control target. S4. Assemble the main crossbeam as a whole, optimize the structural welding sequence, formulate pre-arching process parameters, and control the precision of the bolt hole group. The pre-arching process parameters are as follows: lay the small crossbeam T-shaped flat on the jig and assemble it with the baseline as the reference. During assembly, the middle small crossbeam is pre-lifted 15-18mm towards the U-rib groove side, while the ends of the two small crossbeams remain unchanged. Fine-tune the butt joint ends to ensure that the misalignment of the butt flange plate edges is ≤0.5mm. The welding sequence is as follows: first, weld the crossbeam web butt joint symmetrically, then weld the flange plate butt joint symmetrically. After welding, correct the web flatness and stiffener verticality. The web transverse flatness is ≤1.0mm / m, and the stiffener verticality is ≤1.0mm.

2. The method for controlling the manufacturing precision of ultra-long T-shaped crossbeams of steel trusses according to claim 1, characterized in that, During modeling, the main beam is simultaneously divided into multiple segments according to the block segmentation scheme in the model.

3. The method for controlling the manufacturing precision of ultra-long T-shaped crossbeams of steel trusses according to claim 1, characterized in that, The web of the small crossbeam is cut out using a CNC cutting machine, and the vertical baseline and bevel cutting line of the web are marked on the web, and the butt bevel is flame cut.

4. The method for controlling the manufacturing precision of ultra-long T-shaped crossbeams of steel trusses according to claim 3, characterized in that, The flange plate of the small crossbeam is cut out by a gantry cutting machine and then flame-cut to form a butt bevel.

5. The method for controlling the manufacturing precision of ultra-long T-shaped crossbeams of steel trusses according to claim 4, characterized in that, The assembly of the small crossbeam web and flange plate based on the baseline is specifically as follows: on the jig, with the longitudinal centerline of the flange plate as a reference, the web and flange plate are aligned and positioned to assemble the small crossbeam T-shape, and the bevel of the bottom plate of the flange plate faces the non-crossbeam side during assembly.

6. The method for controlling the manufacturing precision of ultra-long T-shaped crossbeams of steel trusses according to claim 5, characterized in that, The assembly accuracy control targets are specifically: the transverse flatness of the web plate is ≤2.0mm, the longitudinal flatness is ≤3.0mm, the verticality of the stiffening ribs is ≤1.0mm, and the lateral bending is ≤3.0mm.

7. The method for controlling the manufacturing precision of ultra-long T-shaped crossbeams of steel trusses according to claim 1, characterized in that, The precision control of the bolt hole group is as follows: taking the horizontal baseline and vertical baseline as reference, set the upper opening process allowance of the bolt hole group on both sides of the crossbeam, and control the lower opening according to the design size without setting the process allowance. Draw the drilling alignment line of the web plate, and simultaneously draw the matching tangent line of the two ends of the crossbeam web plate. Cut the two ends of the crossbeam according to the matching tangent line, trim the flame-cut parts, and finally use the template and drill holes.

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