Straight-to-curved steel tube arch rib processing chart deepening method

Abstract

The present application relates to the field of steel structure processing and manufacturing, in order to improve the pipe joint arrangement efficiency, provide the straight instead of curved steel pipe arch rib processing map deepening method, including: step 1, determine the theoretical construction arch axis line mode;Step 2, determine the actual processing arch axis line mode: step 21, determine the key requirements of the influence arch rib straight instead of curved processing and manufacturing;Step 22, determine the pipe joint length according to the material plan;Step 23, according to the arch rib plate thickness, the theoretical construction arch axis line mode is partitioned;Step 24, based on the partition result, the length of the straight line segment of the arch rib is determined;Step 25, based on the length of the straight line segment of the arch rib, the actual arrangement mode of the pipe joint is determined from the segmented position or the position connected with the column and the web pipe to form the actual processing arch axis line mode;Step 3, based on the actual processing arch axis line mode, 3D modeling and drawing are carried out. The above-mentioned mode can improve the pipe joint arrangement efficiency.

Description

Technical Field

[0001] This invention relates to the field of steel structure processing and manufacturing, specifically a method for refining the processing drawings of straight steel pipe arch ribs. Background Technology

[0002] Currently, the arch ribs of large-span, large-diameter steel pipe arch bridges are typically fabricated using a "straight instead of curved" construction process. This process imposes strict requirements on parameters such as the straight length of the pipe sections, the maximum distance between the chord and arc, the minimum distance for weld staggering, and the splicing length of the arch rib chord pipes. Therefore, it demands extremely high levels of detail in the fabrication drawings. Currently, pipe sections are typically arranged unidirectionally from one end to the other, with the initial length determined by available pipe sections. When staggering is required, adjacent pipe sections are cut and adjusted to meet the staggering requirements. This method easily results in a large amount of excess material, leading to low steel plate utilization. Furthermore, it hinders the adjustment and modification of internal pipe sections, as any necessary adjustments during the process can easily disrupt the original arrangement. Summary of the Invention

[0003] To improve the efficiency of pipe section layout, this application provides a method for refining the processing drawing of straight steel pipe arch ribs instead of curved ones.

[0004] The technical solution adopted by the present invention to solve the above problems is:

[0005] The method for refining the machining drawings of straight steel pipe arch ribs includes:

[0006] Step 1: Determine the theoretical construction arch axis alignment model;

[0007] Step 2: Determine the actual machining arch axis line mold:

[0008] Step 21: Determine the key requirements affecting the straight-to-curved machining and manufacturing of arch ribs;

[0009] Step 22: Determine the pipe section length according to the material feeding plan;

[0010] Step 23: Divide the theoretical construction arch axis model into sections according to the thickness of the arch rib plate;

[0011] Step 24: Determine the length of the straight segment of the arch rib based on the partitioning results;

[0012] Step 25: Based on the length of the straight section of the arch rib, determine the actual arrangement of the pipe sections from the segment position or the position where they connect with the column and web tube to form the actual processing arch axis line model;

[0013] Step 3: Create 3D models and output drawings based on the actual processed arch axis line model.

[0014] Further, step 1 specifically includes:

[0015] Step 11: Obtain the two-dimensional coordinate values ​​(X, Y1) of each control point of the arch rib according to the arch axis equation information and the coordinate table of the arch rib control points in the design drawings;

[0016] Step 12: Fit the precamber value curve according to the precamber value information in the design drawings to obtain the design precamber value Y2 of each control point of the arch rib;

[0017] Step 13: Superimpose the Y1 and Y2 values ​​to obtain the coordinates of the theoretical construction arch rib control points;

[0018] Step 14: Fit the theoretical construction arch axis model based on the coordinates of the control points of the arch ribs.

[0019] Step 15: Determine the outer contour of the pipe fitting based on the theoretical construction arch axis line model. The pipe fitting includes vertical web pipes and oblique web pipes.

[0020] Furthermore, the key requirements in step 21 include: the maximum distance of the chord-arc difference, the minimum distance of the staggered arch rib welds, the inflection point being on the arch axis after taking into account the pre-arch, and the splicing length of the steel pipe arch chord tube being not less than 1000mm and not less than the diameter of the steel pipe.

[0021] Furthermore, in step 25, the longest pipe section is preferentially used for the connection with the column and the web pipe; the front and rear pipe sections at the segment position and the connecting pipe at the flange are straight pipe sections with the same straight line.

[0022] Furthermore, in step 2, when determining the actual arch axis line mold for processing, the arch axis line mold on one side is laid out based on the symmetry line of the arch rib, and the arch axis line mold on the other side is obtained according to the symmetrical structure.

[0023] Furthermore, after step 25 forms the actual processed arch axis line model, it also includes: establishing a list of surplus materials during the pipe section arrangement process, and numbering the surplus materials of the pipe sections and plate widths.

[0024] Furthermore, the surplus material list includes pipe section number and size, plate width surplus material number and size, and plate width surplus material location.

[0025] The advantages of this invention compared to existing technologies are as follows: This technology employs segmented and regional layout, prioritizing complex locations with numerous branch pipes to improve pipe section arrangement efficiency. Furthermore, a surplus material list is established during the design process, recording steel plate usage information for easy inspection and adjustment, improving pipe section layout efficiency and enabling surplus material management, thereby effectively controlling steel plate loss and increasing steel plate utilization. A precise line model facilitates the creation of 3D models and component output, improving the efficiency of detailed drawings. Attached Figure Description

[0026] Figure 1A flowchart illustrating the process for refining the machining of straight steel pipe arch ribs. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0028] like Figure 1 As shown, the method for refining the machining drawing of a straight steel pipe arch rib includes:

[0029] Step 1: Determine the theoretical construction arch axis alignment model;

[0030] Step 2: Determine the actual machining arch axis line mold:

[0031] Step 21: Determine the key requirements affecting the straight-to-curved machining and manufacturing of arch ribs;

[0032] Step 22: Determine the pipe section length according to the material feeding plan;

[0033] Step 23: Divide the theoretical construction arch axis model into sections according to the thickness of the arch rib plate;

[0034] Step 24: Determine the length of the straight segment of the arch rib based on the partitioning results;

[0035] Step 25: Based on the length of the straight section of the arch rib, determine the actual arrangement of the pipe sections from the segment position or the position where they connect with the column and web tube to form the actual processing arch axis line model;

[0036] Step 3: Create 3D models and output drawings based on the actual processed arch axis line model.

[0037] Specifically, step 1 is as follows:

[0038] Step 11: Obtain the two-dimensional coordinate values ​​(X, Y1) of each control point of the arch rib according to the arch axis equation information and the coordinate table of the arch rib control points in the design drawings. This step mainly involves drawing the original arch axis based on the coordinate points in the primary design, and confirming or verifying whether the data is correct based on the original arch axis. If there are no errors, proceed to the next step.

[0039] Step 12: Fit the pre-camber value curve according to the pre-camber value information in the design drawings to obtain the design pre-camber value Y2 of each control point of the arch rib; this step is also to determine / verify whether the pre-camber value is incorrect. Pre-camber refers to the arching on the original arch axis, so that the original control points become larger in a certain relationship.

[0040] Step 13: Superimpose the Y1 and Y2 values ​​to obtain the coordinates of the theoretical construction arch rib control points;

[0041] Step 14: Fit the theoretical construction arch axis model based on the coordinates of the control points of the arch ribs.

[0042] Step 15: Determine the outer contour of the pipe fittings based on the theoretical construction arch axis line model. The pipe fittings include vertical web tubes and oblique web tubes. Specifically: Connect the control points of the upper and lower chords on the theoretical construction arch axis line model to obtain the center line of the straight web tube, and draw the outer contour of the straight web tube. According to the design requirements for the spacing between the arch rib web tubes, such as the requirement of 80mm for the outer contours of the straight and oblique web tubes in this project, the method for determining the oblique web tube between the two straight web tubes is as follows: Connect the diagonal lengths of the adjacent vertical web tubes of the upper and lower chords, combine them with the outer diameter of the oblique web tube, construct a trigonometric function to obtain the rotation angle, rotate the diagonal line based on the rotation angle, initially determine the position of the oblique web tube contour on the theoretical arch axis model, and draw the outer contour of the oblique web tube. The control points of the upper and lower chords are the arch rib control points mentioned in Step 1.

[0043] Step 21: Determine the key requirements affecting the straight-to-curved manufacturing of arch ribs; including: the maximum distance of the chord-arc difference, the minimum distance of the staggered arch rib welds, the inflection point being on the arch axis after taking into account the pre-camber, and the splicing length of the steel pipe arch chord tube being not less than 1000mm and not less than the diameter of the steel pipe, etc.

[0044] Step 22: Determine the pipe section length according to the material feeding plan; the direction of the welded straight seam pipe roll should be consistent with the rolling direction of the plate. Therefore, determine the longest pipe section length according to the steel plate feeding plan. For example, if the width of the steel plate feeding is 2530mm, remove the cutting edge material and determine that the longest straight pipe section is 2500mm.

[0045] Step 23: Divide the theoretical construction arch axis model into sections according to the thickness of the arch rib plate;

[0046] Step 24: Determine the length of the straight segment of the arch rib based on the partitioning results; According to the plate width and partitioning results, in this embodiment, the length of the straight segment of the arch rib is preferentially determined to be 5m, 4m, 3.5m, etc.

[0047] Step 25: Based on the length of the straight section of the arch rib, determine the actual arrangement of the pipe sections from the segment position, starting position, or position where they connect with the columns or web pipes to form the actual processing arch axis line model. The segment position refers to the segment position of the arch rib sections, which are connected by flanges. For locations with many intersecting joints, the longest pipe section (2.5m) should be used for arrangement. During the arrangement process, the staggering requirements of the circumferential welds need to be considered, such as the net distance between the straight and circumferential welds of the main pipe section and the intersecting weld of the main pipe connection should not be less than 80mm. It is not necessary to determine the staggering of the straight seams of adjacent pipe sections during the arrangement; the straight seam position of the pipe sections can be set according to the actual situation and staggering requirements of adjacent pipe sections before the pipe sections are unfolded during processing and layout. Since the arch rib is usually a symmetrical structure, only half of the arch rib needs to be arranged for pipe sections.

[0048] To ensure the accuracy of the segmented installation of the arch rib chord pipes, the preceding and following pipe sections at each segment location, as well as the connecting pipe at the flange, are determined to be straight pipe sections sharing the same straight line. During the pipe section arrangement, efforts are made to ensure that only one end of each pipe section is located at a bend point, avoiding situations where both ends of a pipe section are angled bends, thus reducing the difficulty of linear control during processing. A bend point is formed because the arch rib is machined using a straight-to-curve method, i.e., assembled from a series of straight pipe sections. A straight section may consist of more than one section; for example, if the design requires a straight section not to exceed 5.6m, but the longest straight pipe section is only 2.5m, multiple pipe sections can be assembled using a straight-line method, resulting in bend points at certain locations.

[0049] When multiple straight pipe sections are adjacent, it is necessary to check whether the straight length and the maximum distance of the chord-arc difference meet the specified requirements while arranging them.

[0050] Through repeated adjustments and optimizations of the above steps, the utilization rate of steel plates was maximized while meeting relevant layout requirements, and excessive kinks were minimized to ensure construction accuracy control and achieve the optimal layout of the arch rib chord tubes. Optimization and adjustment refer to maximizing the utilization rate of steel plates and minimizing excessive kinks while meeting relevant layout requirements to ensure construction accuracy control.

[0051] Furthermore, a surplus material list is established during the pipe section layout process. The surplus material of the pipe section and plate width is numbered. The surplus material list includes the pipe section number and size, the plate width surplus material number and size, the location of the plate width surplus material, and other relevant information. The surplus material is used in a reasonable and prioritized manner, which facilitates modification, adjustment, retrieval, and guidance of production material cutting during the layout process.

[0052] Step 3: Create 3D models and output drawings based on the actual machined arch axis model. This includes:

[0053] 1) Import the actual machined arch axis model after straightening into Tekla software to build a model and create an accurate overall 3D model.

[0054] 2) Generate corresponding part drawings and unfolded part drawings for each section of the chord pipe, and then export the machining drawings. At the same time, number the segmented components according to the component segmentation machining plan, and generate segmented component drawings.

[0055] 3) Process the final unfolded drawing of the steel plate part into a format that can be read by XSuperNEST nesting software.

[0056] 4) The finished round tube (web tube) is exported from the Tekla model as a 3D line model and imported into PIP2000 software for conversion. To ensure the welding quality of the intersection of the web tube and the chord tube, detailed cutting parameters are formulated. One-to-one data processing is performed using PIP2000 software, and then the data is imported into the intersection line cutting machine for direct cutting.

Claims

1. A method for refining the machining drawings of curved steel pipe arch ribs using straight lines, characterized in that: include: Step 1: Determine the theoretical construction arch axis alignment model; Step 2: Determine the actual machining arch axis line mold: Step 21: Determine the key requirements affecting the straight-to-curved machining and manufacturing of arch ribs; Step 22: Determine the pipe section length according to the material feeding plan; Step 23: Divide the theoretical construction arch axis model into sections according to the thickness of the arch rib plate; Step 24: Determine the length of the straight segment of the arch rib based on the zoning results. The length of the straight segment of the arch rib should preferably be determined as 5m, 4m or 3.5m. Step 25: Based on the length of the straight section of the arch rib, determine the actual arrangement of the pipe sections from the segment position or the position where they connect with the column or web tube to form the actual processing arch axis line model; among them, the longest pipe section is preferred for the position where it connects with the column or web tube; the front and rear pipe sections at the segment position and the butt joint at the flange adopt straight pipe sections with the same straight line. Step 3: Create 3D models and output drawings based on the actual processed arch axis line model.

2. The method for refining the machining drawing of straight steel pipe arch ribs according to claim 1, characterized in that, Step 1 specifically involves: Step 11: Obtain the two-dimensional coordinate values ​​(X, Y1) of each control point of the arch rib based on the arch axis equation information and the coordinate table of the arch rib control points in the design drawings. Step 12: Fit the precamber value curve according to the precamber value information in the design drawings to obtain the design precamber value Y2 of each control point of the arch rib; Step 13: Superimpose the Y1 and Y2 values ​​to obtain the coordinates of the theoretical construction arch rib control points; Step 14: Fit the theoretical construction arch axis model based on the coordinates of the control points of the arch ribs. Step 15: Determine the outer contour of the pipe fitting based on the theoretical construction arch axis line model. The pipe fitting includes vertical web pipes and oblique web pipes.

3. The method for refining the machining drawing of straight steel pipe arch ribs according to claim 1, characterized in that, Key requirements in step 21 include: the maximum distance of the chord-arc difference, the minimum distance of the staggered arch rib welds, the inflection point being on the arch axis after taking into account the pre-arch, and the splicing length of the steel pipe arch chord being not less than 1000mm and not less than the diameter of the steel pipe.

4. The method for refining the machining drawing of straight steel pipe arch ribs according to claim 1, characterized in that, In step 2, when determining the actual arch axis line model for processing, the arch axis line model on one side is laid out based on the symmetry line of the arch rib, and the arch axis line model on the other side is obtained according to the symmetrical structure.

5. The method for refining the machining drawing of straight steel pipe arch ribs according to claim 1, characterized in that, After step 25 forms the actual processed arch axis line model, it also includes: establishing a list of surplus materials during the pipe section arrangement process, and numbering the surplus materials of the pipe sections and plate widths.

6. The method for refining the machining drawing of straight steel pipe arch ribs according to claim 5, characterized in that, The surplus material list includes pipe section number and size, plate width surplus material number and size, and plate width surplus material location.

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