A welding method for steel structures

Abstract

The application relates to the technical field of steel structure processing, and discloses a welding method for steel pipes, which comprises the following steps: determining the type of steel pipes for processing, screening out steel pipe samples of the same specification, obtaining the steel pipe samples, numbering, generating a steel pipe sample set, obtaining the cross section of the steel pipe sample, marking a circular area, setting a pretreatment stage and a bending and welding stage, selecting test samples, executing a local bending strategy, marking a bending area, and determining a pretreatment area; marking a cutting point position in the pretreatment area, performing cutting treatment so that the steel pipe is more easily deformed in the bending process, and bending and welding each steel pipe sample.

Description

Technical Field

[0001] This invention relates to the field of steel structure processing technology, specifically a welding method for steel structures; Background Technology

[0002] With the development of industrial automation and intelligent manufacturing, the requirements for the welding quality of steel structures are becoming increasingly stringent. As an important component of steel structures, the welding quality of steel pipes is directly related to the safety and stability of the entire structure. However, traditional steel pipe welding methods have many shortcomings, such as cracks and deformation during the welding process. These problems not only affect the welding quality but also increase the difficulty and cost of subsequent processing.

[0003] Existing steel pipe welding methods lack precise dimensional control and uniform weld quality during processing, especially during bending and welding, where welding defects are prone to occur due to the geometry and material properties of the steel pipe. Furthermore, traditional welding methods often struggle to achieve precise processing and welding when handling steel pipes with complex shapes and specifications, resulting in low production efficiency.

[0004] Therefore, developing a welding method for steel structures, especially a precision welding technology for steel pipes, is of great significance for improving welding quality, optimizing production processes, and reducing manufacturing costs. This new method needs to be able to precisely control the welding process, monitor welding quality in real time, automatically adjust welding parameters, and provide precise processing guidance and quality assessment for steel pipe welding.

[0005] This invention provides a welding method for steel structures. By setting the steel structure type to steel pipe and selecting steel pipe samples of the same specifications according to standard requirements, the method includes a pretreatment stage and a bending and welding stage. Through precise cutting point marking and cutting, as well as bending and welding in the bending and welding stage, this method can achieve optimized control of the steel pipe, improve welding quality, reduce material waste, and increase production efficiency. Summary of the Invention

[0006] This invention provides a welding method for steel structures, which helps to solve the problems mentioned in the background art.

[0007] This invention provides the following technical solution: a welding method for steel structures, wherein, optionally, the type of steel structure to be processed is a steel pipe;

[0008] Set the specifications for screening steel pipes, and select multiple steel pipe samples with the same specifications based on the set specifications.

[0009] The specifications include the inner diameter, outer diameter, and length of the steel pipe.

[0010] Obtain the cross-section of the steel pipe sample and mark the cross-section as a circular area;

[0011] Based on the center position of the circular region, obtain the axis of the steel pipe sample;

[0012] The axis of the steel pipe sample is a circle that passes through the center of all cross-sections of the steel pipe sample and extends along the length of the steel pipe sample.

[0013] Based on the circular area of ​​the steel pipe sample, obtain the outer diameter E and inner diameter T of the steel pipe;

[0014] Calculate the wall thickness Y of the steel pipe based on its outer diameter E and inner diameter T.

[0015] The calculation formula is:

[0016]

[0017] The processing stages for the steel pipe samples are defined as follows:

[0018] Pretreatment stage, bending and welding stage;

[0019] Obtain the preprocessing area of ​​the steel pipe sample;

[0020] In the preprocessing area, the cutting points are marked on the steel pipe sample, and the cutting points are then cut.

[0021] During the bending and welding stage, the steel pipe sample is bent and welded.

[0022] Optionally, in the preprocessing area, marking cutting points on the steel pipe sample and performing cutting processing on the cutting points includes:

[0023] The preprocessing area is shaped like a hollow cylinder, with two bottom surfaces of the hollow cylinder being section A and section B, respectively. Section A and section B are both concentric circles, and the hollow cylinder is marked as hollow cylinder C.

[0024] Find the center of the circle in section A, and denote it as point Z;

[0025] Find the center of the circle in section B, and denote it as point X;

[0026] Connect point Z and point X to form line segment ZX, which is the axis of the hollow cylinder C;

[0027] Draw any straight line through point Z on section A, denoted as line L. Line L intersects the outer circle of section A at two points, denoted as point C and point V respectively.

[0028] Connect point C and point V to form line segment CV;

[0029] Select a point on the outer edge of section B, and the line segment connecting it to point V is the generatrix of the hollow cylinder C, and denoted as point M.

[0030] Connect point M and point X to form line segment MX. Extend line segment MX and intersect it at section B. Let N be the intersection point of line segment MX and section B.

[0031] Connect points C, V, M, and N to form quadrilateral CVMN;

[0032] Mark the cutting points for the quadrilateral CVMN and generate a set of cutting points.

[0033] Optionally, the step of marking the cutting points for the quadrilateral CVMN and generating a set of cutting points includes:

[0034] Establish a three-dimensional coordinate system;

[0035] This makes the axis of the steel pipe parallel to the X-axis;

[0036] Obtain the rotation angle θ;

[0037] The rotation angle is the rotation angle for quadrilateral CVMN, which is the rotation angle for each rotation and bending around the axis in the hollow cylinder C.

[0038] Quadrilateral CVMN is rotated at an angle θ. Each time the rotation is performed, the line segment formed by line segment MV on the hollow cylinder C is recorded and denoted as the first line segment, the second line segment, ..., the Jth line segment. Each line segment has the same length and forms a set called the set of rotated line segments.

[0039] Where J is the number of rotations of quadrilateral CVMN, and this number is less than

[0040] Based on the set of rotating line segments, mark the cutting points for each rotating line segment and generate a set of cutting points.

[0041] Optionally, the step of marking the cutting points for each rotating line segment according to the set of rotating line segments and generating a set of cutting points includes:

[0042] Get any one line segment from the set of rotated line segments, and denote it as the target line segment;

[0043] Set the number of cutting points;

[0044] The number of cutting points is the number of elements in the set of rotating line segments;

[0045] Based on the length of the target line segment and the number of cutting points, obtain the cutting point position of each line segment in the set of rotating line segments, and generate a set of cutting points.

[0046] Optionally, the step of obtaining the cutting point position of each line segment in the set of rotating line segments based on the length of the target line segment and the number of cutting points, and generating a set of cutting points, includes:

[0047] Let the length of the target line segment be D;

[0048] Obtain the cutting point interval value, denoted as R;

[0049] The cutting point interval and the number of rotations are determined based on the specific processing conditions.

[0050] Based on the interval between the set of rotating line segments and the cutting point, obtain the cutting point position of each line segment in the set of rotating line segments.

[0051] Optionally, obtaining the cutting point position of each line segment in the set of rotating line segments based on the interval value between the set of rotating line segments and the cutting point position includes:

[0052] Mark section A as the starting surface and section B as the ending surface;

[0053] Based on the set of rotated line segments, obtain the intersection point of the first line segment and the starting face, and denote it as the starting point;

[0054] The starting point is the cutting point of the first line segment;

[0055] Based on the cutting point interval value R, the cutting points are marked on the second to the Jth line segments respectively, specifically as follows:

[0056] On the second line segment, starting from section A, measure and mark the points along the second line segment that are equidistant from the starting surface by a distance of R, and denote them as the second cutting points;

[0057] On the third line segment, starting from section A, measure and mark the point that is 2R away from the starting surface along the third line segment, and record it as the third cutting point;

[0058] Following the above method, continue to mark the cutting points on the fourth to Jth line segments respectively. The distance from the cutting point on each line segment to the starting face is (line segment number - 1) * R.

[0059] The obtained first cutting point, second cutting point, ..., Jth cutting point are combined into a set, denoted as the cutting point set;

[0060] Based on the set of cutting points, obtain the closed point corresponding to each cutting point;

[0061] Optionally, obtaining the closed point corresponding to each cutting point based on the set of cutting points includes:

[0062] Cut the cutting points to form cutting notches, with each rotating line segment corresponding to one cutting notch;

[0063] Obtain the two closed points on the rotating line segment and the corresponding cutting notch, denoted as F. i ={F i1 ,F i2};

[0064] Where F i Let F be the i-th rotated line segment. i1 Let F be the left closed point of the i-th rotating line segment. i2 It is represented as the right closed point of the i-th rotating line segment.

[0065] Optional, including:

[0066] Based on the set of cutting points, the steel pipe sample is cut at each cutting point, with the cutting direction perpendicular to the axis of the steel pipe sample;

[0067] After cutting at each cutting point, check whether the cut edges are flat;

[0068] If it is not flat, grind the cut edges;

[0069] If the surface is flat, the steel pipe sample is bent and welded.

[0070] Optionally, the bending and welding of the steel pipe sample during the bending and welding stage includes:

[0071] During the bending process, the left and right closed points corresponding to each cutting point of the steel pipe sample are closed;

[0072] The two adjacent regions of the hollow cylinder C are labeled as the first region and the second region, respectively. Both the first region and the second region are hollow cylinders, and the hollow cylinder C is the preprocessing region.

[0073] During the bending process of the hollow cylinder C, its axial direction moves closer to the Z-axis, and the distance between the first region and the second region shortens. After the bending process is completed, the hollow cylinder C presents a spiral shape with its axis close to the Z-axis.

[0074] After the left and right closed points corresponding to each cutting point are closed, the closed parts are welded.

[0075] The present invention has the following beneficial effects:

[0076] 1. This welding method for steel structures ensures consistent dimensions of steel pipes used in the processing by setting unified steel pipe specification standards, thereby improving welding quality. It obtains the cross-section and axis of steel pipe samples, measures the inner and outer diameters and wall thickness of the steel pipes, providing data support for subsequent cutting and welding. In the pre-processing stage, the steel pipe samples are cut to create small notches, which helps the steel pipe deform more easily during bending, reducing crack formation. Cutting is performed at the cutting points to improve the bending quality of the steel pipe and ensure that the shape of the bent steel pipe meets design requirements.

[0077] 2. This welding method for steel structures involves determining the axis and generatrix of a hollow cylinder, obtaining a quadrilateral CVMN, and then using the quadrilateral CVMN to obtain the cutting point. A three-dimensional coordinate system is established, with the steel pipe axis parallel to the X-axis, and the hollow cylinder axis also parallel to the X-axis. The cutting point is then located in three-dimensional space. The rotation angle is first obtained, and the rotational bending angle of the quadrilateral CVMN around the C-axis of the hollow cylinder is determined. The line segments formed by each rotation of the quadrilateral CVMN are recorded, and the length of each line segment is ensured to be consistent, thus ensuring uniform deformation of the steel pipe sample.

[0078] 3. This welding method for steel structures, by setting the number of cutting points and determining the position of each cutting point on each line segment according to the length of the target line segment, and evenly distributing the cutting points in the set of rotating line segments, helps the steel pipe deform more evenly during bending, reducing stress concentration. Precise cutting points help the steel pipe deform more easily during subsequent bending, reducing the generation of cracks. By marking section A as the starting surface and section B as the ending surface, and marking the cutting points according to the interval value R between the set of rotating line segments and the cutting points, the cutting points are evenly distributed on each line segment according to the line segment number and the interval value R, which helps the steel pipe deform more evenly during bending and reduces stress concentration.

[0079] 4. This welding method for steel structures involves cutting the steel pipe sample using a set of cutting points. After each cutting point is completed, an inspection is performed to identify and address any problems that may arise during the cutting process, ensuring the quality of the cut edges. Ensuring the smoothness of the cut edges helps reduce the risk of cracks in the steel pipe during subsequent bending. Grinding or trimming uneven cut edges helps improve the bending quality of the steel pipe sample, ensuring that the bent shape meets the design requirements.

[0080] 5. This welding method for steel structures, unlike traditional bending methods, simply involves bending the steel pipe sample at a right angle, or cutting and bending it along a generatrix of a cylindrical steel pipe. Products processed using this bending and welding method, such as... Figure 5As shown, this will result in a large distance between the first and second regions. When the wall thickness of the steel pipe is too large, the distance between the first and second regions of the steel pipe will be even greater. By cutting and bending the steel pipe on different busbars in this solution, a spiral bend can be formed in the treatment areas of the first and second regions, which can reduce the distance between the first and second regions as much as possible while ensuring the bending angle. Attached Figure Description

[0081] Figure 1 This is a flowchart of the steps of the present invention;

[0082] Figure 2 This is a schematic diagram showing the location of the pretreatment area within the steel pipe;

[0083] Figure 3 This is a schematic diagram of a local structure of the hollow cylinder C, which is also the pre-processing area.

[0084] Figure 4 A schematic diagram showing the location of the cutting point at the hollow cylinder C;

[0085] Figure 5 This is a schematic diagram of a steel pipe after bending in the prior art; Detailed Implementation

[0086] 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.

[0087] Reference Figures 1-5 Set the specifications and standards for screening steel pipes, and select multiple steel pipe samples with the same specifications and standards based on the set specifications and standards.

[0088] The specifications include the inner diameter, outer diameter, and length of the steel pipe.

[0089] Obtain the cross-section of the steel pipe sample and mark the cross-section as a circular area;

[0090] Based on the center position of the circular region, obtain the axis of the steel pipe sample;

[0091] The axis of the steel pipe sample is a circle that passes through the center of all cross-sections of the steel pipe sample and extends along the length of the steel pipe sample.

[0092] Based on the circular area of ​​the steel pipe sample, obtain the outer diameter E and inner diameter T of the steel pipe;

[0093] Calculate the wall thickness Y of the steel pipe based on its outer diameter E and inner diameter T.

[0094] The calculation formula is:

[0095]

[0096] The processing stages for the steel pipe samples are defined as follows:

[0097] Pretreatment stage, bending and welding stage;

[0098] Obtain the preprocessing area of ​​the steel pipe sample;

[0099] In the preprocessing area, the cutting points are marked on the steel pipe sample, and the cutting points are then cut.

[0100] Cutting is performed at the cutting point to create multiple small notches. After the small notches are created, the steel pipe can deform more easily during bending, thereby adapting to bending and reducing cracks caused by excessive compression.

[0101] During the bending and welding stage, the steel pipe sample is bent and welded.

[0102] This welding method for steel structures ensures consistent dimensions of steel pipes used in the processing by establishing standardized steel pipe specifications, thereby improving welding quality. It obtains the cross-section and axis of steel pipe samples, measures the inner and outer diameters and wall thickness, providing data support for subsequent cutting and welding. In the pre-processing stage, the steel pipe samples are cut to create small notches, which facilitates deformation during bending and reduces crack formation. Cutting at the designated points improves the bending quality of the steel pipe, ensuring that the bent pipe shape meets design requirements.

[0103] Optionally, in the preprocessing area, marking cutting points on the steel pipe sample and performing cutting processing on the cutting points includes:

[0104] The preprocessing area is shaped like a hollow cylinder after the steel sample has been cut out, wherein the two bottom surfaces of the hollow cylinder are section A and section B, and section A and section B are both concentric circles;

[0105] Find the center of the circle in section A, and denote it as point Z;

[0106] Find the center of the circle in section B, and denote it as point X;

[0107] Connect point Z and point X to form line segment ZX, which is the axis of the hollow cylinder C;

[0108] Draw any straight line through point Z on section A, denoted as line L. Line L intersects the outer circle of section A at two points, denoted as point C and point V respectively.

[0109] Connect point C and point V to form line segment CV;

[0110] Select a point on the outer edge of section B, and the line segment connecting it to point V is the generatrix of the hollow cylinder C, and denoted as point M.

[0111] Connect point M and point X to form line segment MX. Extend line segment MX and the intersection of this extension with section B is denoted as point N.

[0112] Connect points C, V, M, and N to form quadrilateral CVMN;

[0113] Mark the cutting points for the quadrilateral CVMN and generate a set of cutting points.

[0114] Optionally, the step of marking the cutting points for the quadrilateral CVMN and generating a set of cutting points includes:

[0115] Establish a three-dimensional coordinate system;

[0116] This makes the axis of the steel pipe parallel to the X-axis;

[0117] Obtain the rotation angle θ;

[0118] The rotation angle is the rotation angle for quadrilateral CVMN, which is the rotation angle for each rotation and bending around the axis in the hollow cylinder C.

[0119] During the bending process of the hollow cylinder C, the axial direction of the hollow cylinder C moves closer to the Z-axis, and after the bending is completed, its axial direction is parallel to the Z-axis, and the bent part presents a spiral shape.

[0120] Quadrilateral CVMN is rotated at an angle θ. Each time the rotation is performed, the line segment formed by line segment MV on the hollow cylinder C is recorded and denoted as the first line segment, the second line segment, ..., the Jth line segment. Each line segment has the same length and forms a set called the set of rotated line segments.

[0121] Where J is the number of rotations of quadrilateral CVMN, and this number is less than

[0122] Based on the set of rotating line segments, mark the cutting points for each rotating line segment and generate a set of cutting points.

[0123] By determining the axis and generatrix of the hollow cylinder, a quadrilateral CVMN is obtained, and the cutting point is obtained through the quadrilateral CVMN. A three-dimensional coordinate system is established, and the axis of the steel pipe is parallel to the X-axis. At the same time, the axis of the hollow cylinder is also parallel to the X-axis. Then, the cutting point is located in three-dimensional space. First, the rotation angle is obtained, and the rotation and bending angle of the quadrilateral CVMN around the axis C of the hollow cylinder is determined. The line segments formed by each rotation of the quadrilateral CVMN are recorded, and the length of each line segment is ensured to ensure uniform deformation of the steel pipe sample.

[0124] Furthermore, the step of marking the cutting points for each rotating line segment according to the set of rotating line segments and generating a set of cutting points includes:

[0125] Get any one line segment from the set of rotated line segments, and denote it as the target line segment;

[0126] Set the number of cutting points;

[0127] The number of cutting points is the number of elements in the set of rotating line segments;

[0128] Based on the length of the target line segment and the number of cutting points, obtain the cutting point position of each line segment in the set of rotating line segments, and generate a set of cutting points.

[0129] Optionally, the step of obtaining the cutting point position of each line segment in the set of rotating line segments based on the length of the target line segment and the number of cutting points, and generating a set of cutting points, includes:

[0130] Let the length of the target line segment be D;

[0131] Calculate the interval value of the cutting points, denoted as R;

[0132] like Figure 5 As shown, the larger the interval value of the cutting points, the larger the distance between the first and second areas of the steel pipe after welding. Workers can determine the interval value of the cutting points according to the specific requirements of the distance between the first and second areas.

[0133] Based on the interval between the set of rotating line segments and the cutting point, obtain the cutting point position of each line segment in the set of rotating line segments.

[0134] Furthermore, obtaining the cutting point position of each line segment in the set of rotating line segments based on the interval value between the set of rotating line segments and the cutting point position includes:

[0135] Mark section A as the starting surface and section B as the ending surface;

[0136] Based on the set of rotated line segments, obtain the intersection point of the first line segment and the starting face, and denote it as the starting point;

[0137] The starting point is the cutting point of the first line segment;

[0138] Based on the cutting point interval value R, the cutting points are marked on the second to the Jth line segments respectively, specifically as follows:

[0139] On the second line segment, starting from section A, measure and mark the points along the second line segment that are equidistant from the starting surface by a distance of R, and denote them as the second cutting points;

[0140] On the third line segment, starting from section A, measure and mark the point that is 2R away from the starting surface along the third line segment, and record it as the third cutting point;

[0141] Following the above method, continue to mark the cutting points on the fourth to Jth line segments respectively. The distance from the cutting point on each line segment to the starting face is (line segment number - 1) * R.

[0142] The obtained first cutting point, second cutting point, ..., Jth cutting point are combined into a set, denoted as the cutting point set.

[0143] Based on the set of cutting points, obtain the closed point corresponding to each cutting point;

[0144] Optionally, obtaining the closed point corresponding to each cutting point based on the set of cutting points includes:

[0145] Cut the cutting points to form cutting notches, with each rotating line segment corresponding to one cutting notch;

[0146] Obtain the two closed points on the rotating line segment and the corresponding cutting notch, denoted as F. i ={F i1 ,F i2};

[0147] Where F i Let F be the i-th rotated line segment. i1 Let F be the left closed point of the i-th rotating line segment. i2 It is represented as the right closed point of the i-th rotating line segment.

[0148] Optionally, in the preprocessing area, marking cutting points on the steel pipe sample and performing cutting processing on the cutting points includes:

[0149] Based on the set of cutting points, the steel pipe sample is cut at each cutting point.

[0150] After cutting at each cutting point, check whether the cut edges are flat;

[0151] Check if the cut edges are smooth and free of burrs or unevenness.

[0152] If necessary, grind or trim the cut edges to ensure the bending quality of the steel pipe sample.

[0153] If it is not flat, grind the cut edges;

[0154] If the surface is flat, the steel pipe sample is bent and welded.

[0155] Furthermore, the bending and welding of the steel pipe sample during the bending and welding stage includes:

[0156] During the bending process, the left and right closed points corresponding to each cutting point of the steel pipe sample are closed;

[0157] The two adjacent regions of the hollow cylinder C are labeled as the first region and the second region, respectively. Both the first region and the second region are hollow cylinders, and the hollow cylinder C is the preprocessing region.

[0158] During the bending process of the hollow cylinder C, its axial direction moves closer to the Z-axis, and the distance between the first region and the second region shortens. After the bending process is completed, the hollow cylinder C presents a spiral shape with its axis close to the Z-axis.

[0159] After the left and right closed points corresponding to each cutting point are closed, the closed parts are welded.

[0160] Traditional steel pipe bending methods simply involve bending the steel pipe sample at a right angle, or cutting and bending it along a generatrix of a cylindrical steel pipe. Products manufactured using this bending and welding method, such as... Figure 5 As shown, this will result in a large distance between the first and second regions. When the wall thickness of the steel pipe is too large, the distance between the first and second regions of the steel pipe will be even greater. By cutting and bending the steel pipe on different busbars in this solution, a spiral bend can be formed in the treatment areas of the first and second regions, which can reduce the distance between the first and second regions as much as possible while ensuring the bending angle.

[0161] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0162] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A welding method for steel structures, characterized in that, include, The type of steel structure used for processing is set to steel pipe; Set the specifications for screening steel pipes, and select multiple steel pipe samples with the same specifications based on the set specifications. The specifications include the inner diameter, outer diameter, and length of the steel pipe. Obtain the cross-section of the steel pipe sample and mark the cross-section as a circular area; Based on the center position of the circular region, obtain the axis of the steel pipe sample; The axis of the steel pipe sample is a circle that passes through the center of all cross-sections of the steel pipe sample and extends along the length of the steel pipe sample. Based on the circular area of ​​the steel pipe sample, obtain the outer diameter E and inner diameter T of the steel pipe; Calculate the wall thickness Y of the steel pipe based on its outer diameter E and inner diameter T. The calculation formula is: ； The processing stages for the steel pipe samples are defined as follows: Pretreatment stage, bending and welding stage; Obtain the preprocessing area of ​​the steel pipe sample; In the preprocessing area, the cutting points are marked on the steel pipe sample, and the cutting points are then cut. During the bending and welding stage, the steel pipe sample is bent and welded. In the preprocessing area, the steel pipe sample is marked with cutting points, and the cutting points are then cut, including: The preprocessing area is shaped like a hollow cylinder, with two bottom surfaces of the hollow cylinder being section A and section B, respectively. Section A and section B are both concentric circles, and the hollow cylinder is marked as hollow cylinder C. Find the center of the circle in section A, and denote it as point Z; Find the center of the circle in section B, and denote it as point X; Connect point Z and point X to form line segment ZX, which is the axis of the hollow cylinder C; Draw an arbitrary straight line through point Z on section A, denoted as line L. Line L intersects the outer circle of section A at two points, denoted as point C and point V respectively. Connect point C and point V to form line segment CV; Select a point on the outer edge of section B, and the line segment connecting it to point V is the generatrix of the hollow cylinder C, and denoted as point M. Connect point M and point X to form line segment MX. Extend line segment MX and intersect it at section B. Let N be the intersection point of line segment MX and section B. Connect points C, V, M, and N to form quadrilateral CVMN; Mark the cutting points for the quadrilateral CVMN and generate a set of cutting points; The process of marking the cutting points for the quadrilateral CVMN and generating a set of cutting points includes: Establish a three-dimensional coordinate system; This makes the axis of the steel pipe parallel to the X-axis; Get rotation angle ; The rotation angle is the rotation angle for quadrilateral CVMN, which is the rotation angle for each rotation and bending around the axis in the hollow cylinder C. Quadrilateral CVMN at an angle Perform a rotation. For each rotation, record the line segments formed by line segment MV in the hollow cylinder C, and denot them as the first line segment, the second line segment, ..., the Jth line segment, where each line segment has the same length and they form a set denoted as the set of rotated line segments. Where J is the number of rotations of quadrilateral CVMN, and this number is less than ; Based on the set of rotating line segments, mark the cutting points for each rotating line segment and generate a set of cutting points; The step of marking the cutting points for each rotating line segment according to the set of rotating line segments and generating a set of cutting points includes: Get any one line segment from the set of rotated line segments, and denote it as the target line segment; Set the number of cutting points; The number of cutting points is the number of elements in the set of rotating line segments; Based on the length of the target line segment and the number of cutting points, obtain the cutting point position of each line segment in the set of rotating line segments, and generate a set of cutting points; The step of obtaining the cutting point position of each line segment in the set of rotating line segments based on the length of the target line segment and the number of cutting points, and generating a set of cutting points, includes: Let the length of the target line segment be D; Obtain the cutting point interval value, denoted as R; The cutting point interval and the number of rotations are determined based on the specific processing conditions. Based on the interval between the set of rotating line segments and the cutting point, obtain the cutting point position of each line segment in the set of rotating line segments; The step of obtaining the cutting point position of each line segment in the set of rotating line segments based on the interval value between the set of rotating line segments and the cutting point position includes: Mark section A as the starting surface and section B as the ending surface; Based on the set of rotated line segments, obtain the intersection point of the first line segment and the starting face, and denote it as the starting point; The starting point is the cutting point of the first line segment; Based on the cutting point interval value R, the cutting points are marked on the second to the Jth line segments respectively, specifically as follows: On the second line segment, starting from section A, measure and mark the points along the second line segment that are equidistant from the starting surface by a distance of R, and denote them as the second cutting points; On the third line segment, starting from section A, measure and mark the point that is 2R away from the starting surface along the third line segment, and record it as the third cutting point; Following the above method, continue to mark the cutting points on the fourth to Jth line segments respectively. The distance from the cutting point on each line segment to the starting face is (line segment number - 1) * R. The obtained first cutting point, second cutting point, ..., Jth cutting point are combined into a set, denoted as the cutting point set; Based on the set of cutting points, obtain the closed point corresponding to each cutting point; The step of obtaining the closed point corresponding to each cutting point based on the set of cutting points includes: Cut the cutting points to form cutting notches, with each rotating line segment corresponding to one cutting notch; Obtain the two closed points on the rotating line segment and the corresponding cutting notch, represented as: ={ }; in Let it be the i-th rotated line segment. This is represented as the left closed point of the i-th rotated line segment. It is represented as the right closed point of the i-th rotating line segment.

2. The welding method for steel structures according to claim 1, characterized in that, In the preprocessing area, the steel pipe sample is marked with cutting points, and the cutting points are then cut, including: Based on the set of cutting points, the steel pipe sample is cut at each cutting point, with the cutting direction perpendicular to the axis of the steel pipe sample; After cutting at each cutting point, check whether the cut edges are flat; If it is not flat, grind the cut edges; If the surface is flat, the steel pipe sample is bent and welded.

3. The welding method for steel structures according to claim 1, characterized in that, The bending and welding process of the steel pipe sample during the bending and welding stage includes: During the bending process, the left and right closed points corresponding to each cutting point of the steel pipe sample are closed; The two adjacent regions of the hollow cylinder C are labeled as the first region and the second region, respectively. Both the first region and the second region are hollow cylinders, and the hollow cylinder C is the preprocessing region. During the bending process of the hollow cylinder C, its axial direction moves closer to the Z-axis, and the distance between the first region and the second region shortens. After the bending process is completed, the hollow cylinder C presents a spiral shape with its axis close to the Z-axis. After the left and right closed points corresponding to each cutting point are closed, the closed parts are welded.

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