Method and system for improving welding seam bearing capacity based on pipe end enhanced size optimization

Abstract

The invention relates to the field of pipeline welding, in particular to a method and system for improving the weld joint bearing capacity based on pipe end enhanced size optimization, and the method comprises the steps that a first pipeline to be welded and a second pipeline to be welded are subjected to girth welding to form a girth welding area; a finite element analysis method is adopted to calculate the pipe end enhancement size corresponding to the minimum cost when submerged arc additive treatment is conducted on the girth welding area on the first pipeline and the second pipeline; and according to the pipe end reinforcement size, submerged arc welding is carried out on the first pipeline to form a first submerged arc additive area, and submerged arc welding is carried out on the second pipeline to form a second submerged arc additive area. The thickness and the bearing area of the girth welding area of the pipe end are increased at the lowest cost in a submerged arc welding increasing mode, so that finish machining of the pipe end is achieved, stress-strain concentration at the girth welding area is avoided, complete high-strength matching of the girth welding area on the structure is achieved, and the machining precision is improved. Finally, the purposes of improving the bearing capacity of the girth welding area and reducing the failure risk of the girth welding area are achieved.

Description

Technical Field

[0001] The invention relates to the field of pipeline welding, and in particular to a method and a system for improving the load-bearing capacity of a weld based on optimization of pipe end reinforcement dimensions. Background Art

[0002] With the continuous breakthroughs in various technologies, high-grade steel pipelines are continuously being built and developed. While achieving efficient allocation of oil and gas resources, there are also major risks in the operation of pipelines due to the failure of the girth weld area (also known as the girth weld joint). Achieving high-strength matching in the girth weld area is the most effective way to solve the failure of the girth weld, but it is difficult to achieve complete equal high-strength matching in engineering, which makes the bearing capacity of the girth weld area very low. There are two main ways to improve the bearing capacity of the structure. One is to improve the strength and toughness of the material itself, and the other is to increase the existing size of the structure.

[0003] The existing research technology paths are all centered around improving the toughness of the material itself, and rarely increasing the existing size of the structure. For example, the purpose of improving the tensile and compressive properties of the pipeline through structural reinforcement is to use a plastic short tube and an electric fusion sleeve to fuse, and then the plastic short tube seals the fiber layer inside the fiber prepreg reinforced high-pressure composite pipe to achieve the purpose of pipeline reinforcement; another example is the method of strengthening the end of a thin-walled pipe is achieved through a liner provided inside the thin-walled pipe body.

[0004] In addition, while increasing the existing size of the structure to improve the structural bearing capacity, the investment cost is also increased. Therefore, how to increase the existing size of the structure to improve the structural bearing capacity at the lowest cost is a technical problem that needs to be solved urgently. Summary of the invention

[0005] The present invention provides a method and a system for improving the load-bearing capacity of a weld based on optimization of pipe end reinforcement dimensions, so as to solve the above technical problems.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: A method for improving the load-bearing capacity of a weld based on optimization of pipe end reinforcement dimensions, comprising:

[0007] S1, splicing the pipe ends of a first pipeline and a second pipeline to be welded so that the center lines of the first pipeline and the second pipeline are collinear, and performing girth welding at the splicing position of the pipe ends of the first pipeline and the second pipeline to form a girth welding area; wherein the girth welding area includes a first heat-affected zone connected to the first pipeline, a second heat-affected zone connected to the second pipeline, and a welding material area located between the first heat-affected zone and the second heat-affected zone;

[0008] S2, using a finite element analysis method to calculate the pipe end reinforcement size corresponding to the minimum cost when performing submerged arc additive processing on the circumferential welding area on the first pipe and the second pipe;

[0009] S3, according to the pipe end reinforcement size, performing submerged arc welding on the first pipe and close to the first heat affected zone to form a first submerged arc material enhancement zone, and performing submerged arc welding on the second pipe and close to the second heat affected zone to form a second submerged arc material enhancement zone.

[0010] Based on the above technical solution, the present invention can also be improved as follows.

[0011] Furthermore, the first submerged arc material adding zone and the second submerged arc material adding zone are centrally symmetrical with respect to the welding material zone.

[0012] Furthermore, one end of the first submerged arc additive zone away from the first heat affected zone forms an angle with the central axis of the first pipe at a preset angle to transition to the outer surface of the first pipe; one end of the second submerged arc additive zone away from the second heat affected zone forms an angle with the central axis of the second pipe at a preset angle to transition to the outer surface of the second pipe.

[0013] Further, the tube end enhancement dimensions include the additive length and additive thickness of the first submerged arc additive zone or the second submerged arc additive zone; S2 includes:

[0014] S21, based on the first pipeline, the second pipeline and the girth weld area, a pipeline girth weld model is constructed by using a finite element analysis method, and a given axial tensile load is applied to the pipeline girth weld model to obtain a crack driving force curve of the pipeline girth weld area before submerged arc material addition at the pipe end that varies with the axial tensile strain;

[0015] S22, based on the crack driving force curve of the pipe girth weld area before submerged arc material addition with axial tensile strain, the ultimate strain bearing capacity of the girth weld under different material addition schemes was analyzed, and the surfaces with X, Y, and Z coordinates as the material addition length, material addition thickness, and ultimate strain bearing capacity were fitted.

[0016] S23, in the curved surface, by setting the value of the ultimate strain bearing capacity of the Z axis, a combination curve of the additive length and the additive thickness corresponding to the strain bearing capacity requirement is obtained;

[0017] S24, rounding up the minimum additive thickness and the maximum additive thickness on the combination scheme curve, respectively, and taking values ​​at intervals of preset thickness within the range of the minimum additive thickness rounding up and the maximum additive thickness rounding up, to obtain a plurality of additive thickness schemes, and based on the combination scheme curve, obtaining a plurality of additive length schemes corresponding to the plurality of additive thickness schemes one by one;

[0018] Or, the minimum additive length and the maximum additive length on the combination scheme curve are rounded up respectively, and within the range of the minimum additive length rounded up and the maximum additive length rounded up, the values ​​are taken at intervals of a preset length to obtain a plurality of additive length schemes, and based on the combination scheme curve, a plurality of additive thickness schemes corresponding to the plurality of additive length schemes are obtained one by one;

[0019] S25, taking the additive thickness and the additive length as decision variables, taking minimizing the pipeline additive cost as the optimization objective function, selecting and comparing the multiple additive thickness schemes and the corresponding multiple additive length schemes, and obtaining the additive length and additive thickness combination scheme corresponding to the minimum additive cost.

[0020] Further, in S21, the pipeline girth weld model is constructed by using a finite element analysis method, specifically: the pipeline girth weld model is constructed by using ABAQUS software.

[0021] Furthermore, in S21: the crack driving force is characterized by the crack tip opening displacement.

[0022] Further, in S22: specifically using the Organic software to perform data analysis on the ultimate strain bearing capacity values ​​of the girth weld under different additive schemes.

[0023] Further, in said S24:

[0024] When the minimum additive thickness and the maximum additive thickness on the combination scheme curve are rounded up respectively, and after obtaining a plurality of additive length schemes corresponding to the plurality of additive thickness schemes one by one, the method further includes rounding up the plurality of additive length schemes;

[0025] When the minimum additive length and the maximum additive length on the combination scheme curve are rounded up respectively, and after obtaining a plurality of additive thickness schemes corresponding one-to-one to the plurality of additive length schemes, the method further includes rounding up the plurality of additive thickness schemes.

[0026] Further, in S25, the optimization objective function is:

[0027] F'=minF=4πfρt0R0L0;

[0028] Wherein, ρ represents the material density of the additive, f represents the unit price of the additive material, R0 represents the outer diameter of the first pipe or the second pipe, F represents the cost corresponding to different combinations of additive length and additive thickness, F' represents the minimum value of F, t0 represents the additive thickness, and L0 represents the additive length.

[0029] Based on the above method for improving the load-bearing capacity of a weld based on optimization of the pipe end reinforcement size, the present invention also provides a system for improving the load-bearing capacity of a weld based on optimization of the pipe end reinforcement size, the system comprising:

[0030] A girth welding processing module, which is used to splice the pipe ends of the first pipe and the second pipe to be welded, so that the center lines of the first pipe and the second pipe are collinear, and girth welding is performed at the splicing position of the pipe ends of the first pipe and the second pipe to form a girth welding area; wherein the girth welding area includes a first heat-affected zone connected to the first pipe, a second heat-affected zone connected to the second pipe, and a welding material area located between the first heat-affected zone and the second heat-affected zone;

[0031] A pipe end reinforcement size optimization module, which is used to calculate the pipe end reinforcement size corresponding to the minimum cost when performing submerged arc additive processing on the circumferential welding area on the first pipe and the second pipe using a finite element analysis method;

[0032] A submerged arc additive processing module is used to perform submerged arc welding on the first pipe and close to the first heat affected zone according to the pipe end reinforcement size to form a first submerged arc additive zone, and to perform submerged arc welding on the second pipe and close to the second heat affected zone to form a second submerged arc additive zone.

[0033] The beneficial effects of the present invention are as follows: the present invention is based on a method and system for improving the load-bearing capacity of the weld by optimizing the enhanced dimensions of the pipe end, and increases the thickness and load-bearing area of ​​the ring weld area of ​​the pipe end by submerged arc welding at the lowest cost to achieve fine processing of the pipe end, thereby avoiding stress and strain concentration in the ring weld area, and further achieving complete high-strength matching of the ring weld area structure, and ultimately achieving the purpose of improving the load-bearing capacity of the ring weld area and reducing the failure risk of the ring weld area. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A flow chart of a method for improving the load-bearing capacity of a weld based on optimization of pipe end reinforcement size according to the present invention;

[0035] Figure 2 A schematic diagram of a pipeline structure obtained by using the method of the present invention for improving the load-bearing capacity of a weld based on optimization of the pipe end reinforcement size;

[0036] Figure 3 Flow chart for optimizing pipe end reinforcement size;

[0037] Figure 4 The surface diagram of X, Y, and Z coordinates are respectively the additive length, additive thickness, and ultimate strain bearing capacity;

[0038] Figure 5It is a schematic diagram of the combination curve of the additive length and thickness under different strain bearing capacity requirements;

[0039] Figure 6 The structure block diagram of the system for improving the load-bearing capacity of the weld based on the optimization of the pipe end reinforcement size of the present invention. DETAILED DESCRIPTION

[0040] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0041] like Figure 1 As shown, the method for improving the load-bearing capacity of the weld based on the optimization of the pipe end reinforcement size includes:

[0042] S1, splicing the pipe ends of a first pipeline and a second pipeline to be welded so that the center lines of the first pipeline and the second pipeline are collinear, and performing girth welding at the splicing position of the pipe ends of the first pipeline and the second pipeline to form a girth welding area; wherein the girth welding area includes a first heat-affected zone connected to the first pipeline, a second heat-affected zone connected to the second pipeline, and a welding material area located between the first heat-affected zone and the second heat-affected zone;

[0043] S2, using a finite element analysis method to calculate the pipe end reinforcement size corresponding to the minimum cost when performing submerged arc additive processing on the circumferential welding area on the first pipe and the second pipe;

[0044] S3, according to the pipe end reinforcement size, performing submerged arc welding on the first pipe and close to the first heat affected zone to form a first submerged arc material enhancement zone, and performing submerged arc welding on the second pipe and close to the second heat affected zone to form a second submerged arc material enhancement zone.

[0045] Figure 2The schematic diagram of the pipeline structure obtained by the method of the present invention based on the optimization of pipe end reinforcement size to improve the bearing capacity of the weld is shown in FIG. The first pipeline 10 and the second pipeline 20 have the same outer diameter, and the first pipeline 10 and the second pipeline 20 form a weld area 30 due to girth welding, and the weld area 30 includes a first heat-affected zone 302 connected to the first pipeline 10, a second heat-affected zone 303 connected to the second pipeline 20, and a weld material area 301 located between the first heat-affected zone 302 and the second heat-affected zone 303. The first submerged arc material-increasing zone 304 and the second submerged arc material-increasing zone 305 are welded to the surface of the first pipeline 10 and the second pipeline 20 through submerged arc material-increasing treatment, and are closely fitted with the first heat-affected zone 302 and the second heat-affected zone 303, and the first submerged arc material-increasing zone 304 and the second submerged arc material-increasing zone 305 are centrally symmetrical relative to the weld material area 301. One end of the first submerged arc material-additive zone 304 away from the first heat-affected zone 302 forms a preset angle with the central axis of the first pipe 10 to transition to the outer surface of the first pipe 10; one end of the second submerged arc material-additive zone 305 away from the second heat-affected zone 20 forms a preset angle with the central axis of the second pipe 20 to transition to the outer surface of the second pipe 20. Preferably, the preset angle is 37.5°.

[0046] In this embodiment, since the first submerged arc material-enhancing zone or the second submerged arc material-enhancing zone has the same size, the tube end enhancement size is the material-enhancing length and material-enhancing thickness of the first submerged arc material-enhancing zone or the second submerged arc material-enhancing zone. Figure 2 In the figure, L0 represents the additive length and t0 represents the additive thickness.

[0047] like Figure 3 As shown, the S2 includes:

[0048] S21, based on the first pipeline, the second pipeline and the girth weld area, a pipeline girth weld model is constructed by using a finite element analysis method, and a given axial tensile load is applied to the pipeline girth weld model to obtain a crack driving force curve of the pipeline girth weld area before submerged arc material addition at the pipe end that varies with the axial tensile strain;

[0049] S22, based on the crack driving force curve of the pipe girth weld area before submerged arc material addition with axial tensile strain, the ultimate strain bearing capacity of the girth weld under different material addition schemes was analyzed, and the surfaces with X, Y, and Z coordinates as the material addition length, material addition thickness, and ultimate strain bearing capacity were fitted.

[0050] S23, in the curved surface, by setting the value of the ultimate strain bearing capacity of the Z axis, a combination curve of the additive length and the additive thickness corresponding to the strain bearing capacity requirement is obtained;

[0051] S24, rounding up the minimum additive thickness and the maximum additive thickness on the combination scheme curve, respectively, and taking values ​​at intervals of preset thickness within the range of the minimum additive thickness rounding up and the maximum additive thickness rounding up, to obtain a plurality of additive thickness schemes, and based on the combination scheme curve, obtaining a plurality of additive length schemes corresponding to the plurality of additive thickness schemes one by one;

[0052] Or, the minimum additive length and the maximum additive length on the combination scheme curve are rounded up respectively, and within the range of the minimum additive length rounded up and the maximum additive length rounded up, the values ​​are taken at intervals of a preset length to obtain a plurality of additive length schemes, and based on the combination scheme curve, a plurality of additive thickness schemes corresponding to the plurality of additive length schemes are obtained one by one;

[0053] S25, taking the additive thickness and the additive length as decision variables, taking minimizing the pipeline additive cost as the optimization objective function, selecting and comparing the multiple additive thickness schemes and the corresponding multiple additive length schemes, and obtaining the additive length and additive thickness combination scheme corresponding to the minimum additive cost.

[0054] Specifically, in S21, the pipeline girth weld model is constructed by using the finite element analysis method: the pipeline girth weld model is constructed by using ABAQUS software. The crack driving force is characterized by the crack tip opening displacement (CTOD).

[0055] Specifically, in S22: using the Origin software, data analysis is performed on the ultimate strain bearing capacity values ​​of the girth weld under different material addition schemes.

[0056] Figure 4 The X, Y, and Z coordinates are the surface of the additive length, additive thickness, and ultimate strain bearing capacity, respectively. In this embodiment, the Z-axis ultimate strain bearing capacity is set to 0.5%, 1.0%, 1.5%, 2.0%, and 2.5%, and five corresponding ultimate strain bearing capacity contour lines are obtained, such as Figure 4 ; Then, we can get the combination curve of additive length and thickness under different strain bearing capacity requirements, such as Figure 5 shown.

[0057] Specifically, in S24:

[0058] When the minimum additive thickness and the maximum additive thickness on the combination scheme curve are rounded up respectively, and after obtaining a plurality of additive length schemes corresponding to the plurality of additive thickness schemes one by one, the method further includes rounding up the plurality of additive length schemes;

[0059] When the minimum additive length and the maximum additive length on the combination scheme curve are rounded up respectively, and after obtaining a plurality of additive thickness schemes corresponding one-to-one to the plurality of additive length schemes, the method further includes rounding up the plurality of additive thickness schemes.

[0060] Each point on the curve of the combination scheme of additive length and additive thickness meets the requirements of pipeline bearing strain. In order to facilitate on-site welding operations, the present invention rounds up the minimum and maximum values ​​of the additive length or additive thickness in the enhancement scheme. Specifically in this embodiment, this embodiment takes the minimum additive thickness and the maximum additive thickness on the curve of the combination scheme as an example, and takes values ​​at intervals of 0.5 mm of the preset thickness within the rounding interval to obtain multiple additive thickness schemes, and based on the combination scheme curve, multiple additive length schemes corresponding to the multiple additive thickness schemes are obtained.

[0061] In this embodiment, in S25, the optimization objective function is:

[0062] F'=minF=4πfρt0R0L0;

[0063] Where ρ represents the material density of the additive (kg / m 3 ), f represents the unit price of the additive material (yuan / kg), R0 represents the outer diameter of the first pipe or the second pipe (mm), F represents the cost corresponding to different combinations of additive lengths and additive thicknesses, F' represents the minimum value of F, t0 represents the additive thickness, and L0 represents the additive length.

[0064] Since the outer diameter R0, material density ρ and material unit price f are fixed after selection, the optimization objective function can be transformed into the problem of minimizing the product of the reinforcement length L0 and the reinforcement thickness t0. Among them:

[0065]

[0066] Based on the above method, the additive length and thickness combination scheme corresponding to the minimum additive cost can be finally obtained. The additive length and thickness combination scheme corresponding to the additive cost is shown in Table 1. If the minimum additive cost corresponds to multiple additive schemes, one of the schemes can be selected according to the actual welding conditions on site.

[0067] Table 1: Additive material length and thickness combinations corresponding to additive material costs

[0068]

[0069]

[0070] The method of improving the bearing capacity of the weld based on the optimization of the pipe end reinforcement size in the present invention, according to the actual t0 and the actual L0, uses the submerged arc additive method to thicken the pipe end in the area near the girth weld area on the outer surface of the pipeline, so as to solve the problem of high-strength matching that is difficult to achieve in the girth weld area of ​​high-grade steel oil and gas pipelines, reduce the probability of stress concentration in the girth weld area, and effectively improve the bearing capacity of the girth weld area, which is of great significance to ensuring the intrinsic safety of high-grade steel oil and gas pipelines.

[0071] Based on the above method for improving the load-bearing capacity of a weld based on optimization of the pipe end reinforcement size, the present invention also provides a system for improving the load-bearing capacity of a weld based on optimization of the pipe end reinforcement size.

[0072] like Figure 6 As shown, the system based on the optimization of pipe end reinforcement size to improve the load-bearing capacity of the weld includes:

[0073] A girth welding processing module, which is used to splice the pipe ends of the first pipe and the second pipe to be welded, so that the center lines of the first pipe and the second pipe are collinear, and girth welding is performed at the splicing position of the pipe ends of the first pipe and the second pipe to form a girth welding area; wherein the girth welding area includes a first heat-affected zone connected to the first pipe, a second heat-affected zone connected to the second pipe, and a welding material area located between the first heat-affected zone and the second heat-affected zone;

[0074] A pipe end reinforcement size optimization module, which is used to calculate the pipe end reinforcement size corresponding to the minimum cost when performing submerged arc additive processing on the circumferential welding area on the first pipe and the second pipe using a finite element analysis method;

[0075] A submerged arc additive processing module is used to perform submerged arc welding on the first pipe and close to the first heat affected zone according to the pipe end reinforcement size to form a first submerged arc additive zone, and to perform submerged arc welding on the second pipe and close to the second heat affected zone to form a second submerged arc additive zone.

[0076] The specific functions of each module in the system for improving the load-bearing capacity of the weld based on the optimization of the pipe end reinforcement size of the present invention can be found in the specific steps of the method for improving the load-bearing capacity of the weld based on the optimization of the pipe end reinforcement size of the present invention, and will not be repeated again.

[0077] The present invention is based on a method and system for optimizing the size of pipe end reinforcement to improve the bearing capacity of the weld. By developing or selecting suitable additive materials, the submerged arc additive method is used to thicken the pipe end to solve the problem of high-strength matching that is difficult to achieve in the girth welding area of ​​high-grade oil and gas pipelines, effectively improve the bearing capacity of the girth welding area, and ensure the intrinsic safety of the oil and gas pipeline. In addition, based on the finite element analysis method to optimize the pipe end size design, the cost of pipe end reinforcement length and thickness of the pipeline strain bearing capacity can be minimized, and the strain bearing capacity of the pipeline girth weld can be improved to achieve fine processing of the pipe end, thereby avoiding stress and strain concentration in the girth welding area, and then achieving complete high-strength matching in the girth welding area structure, and finally achieving the purpose of improving the bearing capacity of the girth welding area and reducing the risk of failure of the girth welding area.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for improving the load-bearing capacity of a weld based on optimization of pipe end reinforcement dimensions, characterized in that: include: S1, splicing the pipe ends of a first pipeline and a second pipeline to be welded so that the center lines of the first pipeline and the second pipeline are collinear, and performing girth welding at the splicing position of the pipe ends of the first pipeline and the second pipeline to form a girth welding area; wherein the girth welding area includes a first heat-affected zone connected to the first pipeline, a second heat-affected zone connected to the second pipeline, and a welding material area located between the first heat-affected zone and the second heat-affected zone; S2, using a finite element analysis method to calculate the pipe end reinforcement size corresponding to the minimum cost when performing submerged arc additive processing on the circumferential welding area on the first pipe and the second pipe; S3, according to the pipe end reinforcement size, performing submerged arc welding on the first pipe and close to the first heat affected zone to form a first submerged arc material enhancement zone, and performing submerged arc welding on the second pipe and close to the second heat affected zone to form a second submerged arc material enhancement zone.

2. The method for improving the load-bearing capacity of welds based on optimization of pipe end reinforcement dimensions according to claim 1, characterized in that: The first submerged arc material adding zone and the second submerged arc material adding zone are centrally symmetrical with respect to the welding material zone.

3. The method for improving the load-bearing capacity of welds based on optimization of pipe end reinforcement dimensions according to claim 1, characterized in that: One end of the first submerged arc additive zone away from the first heat affected zone forms an angle with the central axis of the first pipe at a preset angle to transition to the outer surface of the first pipe; one end of the second submerged arc additive zone away from the second heat affected zone forms an angle with the central axis of the second pipe at a preset angle to transition to the outer surface of the second pipe.

4. The method for improving the load-bearing capacity of welds based on optimization of pipe end reinforcement dimensions according to claim 1, characterized in that: The tube end enhancement dimensions include the material enhancement length and material enhancement thickness of the first submerged arc material enhancement zone or the second submerged arc material enhancement zone; S2 includes: S21, based on the first pipeline, the second pipeline and the girth weld area, a pipeline girth weld model is constructed by using a finite element analysis method, and a given axial tensile load is applied to the pipeline girth weld model to obtain a crack driving force curve of the pipeline girth weld area before submerged arc material addition at the pipe end that varies with the axial tensile strain; S22, based on the crack driving force curve of the pipe girth weld area before submerged arc material addition with axial tensile strain, the ultimate strain bearing capacity of the girth weld under different material addition schemes was analyzed, and the surfaces with X, Y, and Z coordinates as the material addition length, material addition thickness, and ultimate strain bearing capacity were fitted. S23, in the curved surface, by setting the value of the ultimate strain bearing capacity of the Z axis, a combination curve of the additive length and the additive thickness corresponding to the strain bearing capacity requirement is obtained; S24, rounding up the minimum additive thickness and the maximum additive thickness on the combination scheme curve, respectively, and taking values ​​at intervals of preset thickness within the range of the minimum additive thickness rounding up and the maximum additive thickness rounding up, to obtain a plurality of additive thickness schemes, and based on the combination scheme curve, obtaining a plurality of additive length schemes corresponding to the plurality of additive thickness schemes one by one; Or, the minimum additive length and the maximum additive length on the combination scheme curve are rounded up respectively, and within the range of the minimum additive length rounded up and the maximum additive length rounded up, the values ​​are taken at intervals of a preset length to obtain a plurality of additive length schemes, and based on the combination scheme curve, a plurality of additive thickness schemes corresponding to the plurality of additive length schemes are obtained one by one; S25, taking the additive thickness and the additive length as decision variables, taking minimizing the pipeline additive cost as the optimization objective function, selecting and comparing the multiple additive thickness schemes and the corresponding multiple additive length schemes, and obtaining the additive length and additive thickness combination scheme corresponding to the minimum additive cost.

5. The method for improving the load-bearing capacity of welds based on optimization of pipe end reinforcement dimensions according to claim 4, characterized in that: In the S21, the pipeline girth weld model is constructed by using the finite element analysis method, specifically: the pipeline girth weld model is constructed by using ABAQUS software.

6. The method for improving the load-bearing capacity of welds based on optimization of pipe end reinforcement dimensions according to claim 4, characterized in that: In S21: the crack driving force is characterized by the crack tip opening displacement.

7. The method for improving the load-bearing capacity of welds based on optimization of pipe end reinforcement dimensions according to claim 4, characterized in that: In said S22: specifically using Origin software to perform data analysis on the ultimate strain bearing capacity values ​​of the girth weld under different additive schemes.

8. The method for improving the load-bearing capacity of welds based on optimization of pipe end reinforcement dimensions according to claim 4, characterized in that: In said S24: When the minimum additive thickness and the maximum additive thickness on the combination scheme curve are rounded up respectively, and after obtaining a plurality of additive length schemes corresponding to the plurality of additive thickness schemes one by one, the method further includes rounding up the plurality of additive length schemes; When the minimum additive length and the maximum additive length on the combination scheme curve are rounded up respectively, and after obtaining a plurality of additive thickness schemes corresponding one-to-one to the plurality of additive length schemes, the method further includes rounding up the plurality of additive thickness schemes.

9. The method for improving the load-bearing capacity of welds based on optimization of pipe end reinforcement dimensions according to claim 4, characterized in that: In S25, the optimization objective function is: F'=minF=4πfρt0R0L0; Wherein, ρ represents the material density of the additive, f represents the unit price of the additive material, R0 represents the outer diameter of the first pipe or the second pipe, F represents the cost corresponding to different combinations of additive length and additive thickness, F' represents the minimum value of F, t0 represents the additive thickness, and L0 represents the additive length.

10. A system for improving the load-bearing capacity of welds based on optimization of pipe end reinforcement dimensions, characterized in that: include: A girth welding processing module, which is used to splice the pipe ends of the first pipe and the second pipe to be welded, so that the center lines of the first pipe and the second pipe are collinear, and girth welding is performed at the splicing position of the pipe ends of the first pipe and the second pipe to form a girth welding area; wherein the girth welding area includes a first heat-affected zone connected to the first pipe, a second heat-affected zone connected to the second pipe, and a welding material area located between the first heat-affected zone and the second heat-affected zone; A pipe end reinforcement size optimization module, which is used to calculate the pipe end reinforcement size corresponding to the minimum cost when performing submerged arc additive processing on the circumferential welding area on the first pipe and the second pipe using a finite element analysis method; A submerged arc additive processing module is used to perform submerged arc welding on the first pipe and close to the first heat affected zone according to the pipe end reinforcement size to form a first submerged arc additive zone, and to perform submerged arc welding on the second pipe and close to the second heat affected zone to form a second submerged arc additive zone.

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