Model fitting method, strain bearing capacity determination method, device and electronic equipment

Abstract

The present application provides a model fitting method, a strain bearing capacity determination method, a device and an electronic device. The model fitting method comprises: determining the geometric partition of the girth weld joint based on a preset metallographic diagram of the girth weld joint, selecting a material constitutive model for each partition, and establishing a finite element model of the girth weld joint; quantitatively analyzing the influence of geometric parameters, material parameters and load parameters on the crack driving force of the girth weld joint based on a crack driving force curve under different combination conditions obtained by finite element calculation of the finite element model, and determining key parameters with preset influences; obtaining the bearing strain of the girth weld joint containing cracks under different fracture toughness values ​​based on the crack driving force curve; performing nonlinear fitting analysis on the bearing strain and key parameters to obtain a prediction model for the strain bearing capacity of the girth weld joint. The present application can obtain a prediction model for the strain bearing capacity of a pipeline girth weld joint with a wide range of applications.

Description

Technical Field

[0001] The present application relates to the field of computer technology, and in particular to a model fitting method, a strain bearing capacity determination method, a device and an electronic device. Background Art

[0002] With the increasing demand for oil and gas energy and the continuous construction and development of pipeline engineering projects, the scale of my country's oil and gas pipeline trunk lines is also continuing to expand. Among them, docking and welding between pipe sections are necessary links in the pipeline construction process. During welding, the metal material is melted and solidified by the high-temperature welding heat source, and a girth weld will eventually be formed. Partitions with different material properties will be formed near the girth weld, including the weld zone, heat-affected zone, and parent material zone. In addition, due to factors such as welding process, technology, and construction conditions, various defects such as pores, slag inclusions, incomplete penetration, incomplete fusion, undercuts, and cracks may occur during pipeline welding, which will cause the girth weld to be under multiple discontinuous conditions in terms of geometry and material, which will cause the girth weld to become the weakest link in the buried pipeline, that is, it is easy to cause fracture.

[0003] Therefore, it is urgent to carry out hidden danger investigation and control and applicability evaluation methods for pipeline girth welds to ensure the safety of pipeline girth welds. Summary of the invention

[0004] Multiple aspects of the present application provide a model fitting method, a strain bearing capacity determination method, a device and an electronic device to solve the problem that it is currently impossible to provide a pipe girth weld joint bearing strain prediction model with a wide range of applications.

[0005] The first aspect of an embodiment of the present application provides a model fitting method, comprising: based on a preset metallographic diagram of a girth weld joint, determining the geometric partitions of the girth weld joint, selecting a material constitutive model for each partition, and establishing a finite element model of the girth weld joint, wherein the material properties of different geometric partitions are different, and the fusion line position of the girth weld joint contains an inner surface crack; based on a crack driving force curve under different combination conditions obtained by finite element calculation of the finite element model, quantitatively analyzing the influence of geometric parameters, material parameters and load parameters on the crack driving force of the girth weld joint, and determining key parameters with preset influences; based on the crack driving force curve, obtaining the bearing strain of the girth weld joint containing cracks at different fracture toughness values; performing nonlinear fitting analysis on the bearing strain and key parameters to obtain a prediction model for the strain bearing capacity of the girth weld joint, and the prediction model is used to determine the bearing strain of the girth weld joint.

[0006] A second aspect of an embodiment of the present application provides a method for determining strain bearing capacity, comprising: obtaining target parameters of a target ring weld joint, the target parameters comprising: target geometric parameters, target material parameters and target load parameters of the target ring weld joint; inputting the target parameters into a prediction model for analysis to obtain a target ring weld joint bearing strain value, the bearing strain value representing the strain bearing capacity of the target ring weld joint, and the prediction model is determined using the model fitting method of any one of the first aspects.

[0007] A third aspect of the embodiments of the present application provides a model fitting device, comprising:

[0008] A construction module is used to determine the geometric partitions of the girth weld joint based on a preset metallographic diagram of the girth weld joint, select a material constitutive model for each partition, and establish a finite element model of the girth weld joint, wherein the material properties of different geometric partitions are different, and the fusion line of the girth weld joint contains an inner surface crack;

[0009] An analysis module is used to quantitatively analyze the influence of geometric parameters, material parameters and load parameters on the crack driving force of the girth weld joint based on the crack driving force curves under different combination conditions obtained by finite element calculation of the finite element model, and determine the key parameters with preset influence;

[0010] An acquisition module is used to obtain the bearing strain of the cracked girth weld joint at different fracture toughness values ​​based on the crack driving force curve;

[0011] The fitting module is used to perform nonlinear fitting analysis on the bearing strain and key parameters to obtain a prediction model for the strain bearing capacity of the girth weld joint. The prediction model is used to determine the bearing strain of the girth weld joint.

[0012] A fourth aspect of an embodiment of the present application provides a device for determining strain bearing capacity, comprising:

[0013] An acquisition module is used to acquire target parameters of a target girth weld joint, wherein the target parameters include: target geometric parameters, target material parameters and target load parameters of the target girth weld joint;

[0014] The analysis module is used to input the target parameters into the prediction model for analysis to obtain the target girth weld joint bearing strain value, the bearing strain value represents the strain bearing capacity of the target girth weld joint, and the prediction model is determined by the model fitting method of any one of the first aspects.

[0015] A fifth aspect of an embodiment of the present application provides an electronic device, comprising: a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the model fitting method of the first aspect or the strain bearing capacity determination method of the second aspect is implemented.

[0016] A sixth aspect of an embodiment of the present application provides a computer-readable storage medium, in which computer execution instructions are stored. When the computer execution instructions are executed by a processor, they are used to implement the model fitting method or strain bearing capacity determination method provided in any of the above method embodiments.

[0017] A seventh aspect of an embodiment of the present application provides a computer program product, the program product comprising: a computer program, the computer program is stored in a readable storage medium, at least one processor of an electronic device can read the computer program from the readable storage medium, and at least one processor executes the computer program so that the electronic device executes the model fitting method or strain bearing capacity determination method provided in any of the above method embodiments.

[0018] The embodiment of the present application is applied in the scenario of determining the bearing capacity of the weld of the pipeline. The geometric partition of the girth weld joint is determined based on the preset metallographic diagram of the girth weld joint, and the material constitutive model of each partition is selected to establish a finite element model of the girth weld joint, wherein the material properties of different geometric partitions are different, and the fusion line position of the girth weld joint contains an inner surface crack; based on the crack driving force curve under different combination conditions obtained by finite element calculation of the finite element model, the influence of geometric parameters, material parameters and load parameters on the crack driving force of the girth weld joint is quantitatively analyzed, and the key parameters with preset influence are determined; based on the crack driving force curve, the bearing strain of the girth weld joint containing cracks at different fracture toughness values ​​is obtained; the bearing strain and the key parameters are subjected to nonlinear fitting analysis to obtain a prediction model for the strain bearing capacity of the girth weld joint, and the prediction model is used to determine the bearing strain of the girth weld joint, and a prediction model for the strain bearing capacity of the girth weld joint of a pipeline with a wide range of applications can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0020] Figure 1 An application scenario diagram of a model fitting method provided for an exemplary embodiment of the present application;

[0021] Figure 2 A flowchart of a model fitting method provided for an exemplary embodiment of the present application;

[0022] Figure 3 A test schematic diagram of a prediction model provided for an exemplary embodiment of the present application;

[0023] Figure 4 A flowchart of a method for determining strain bearing capacity provided for an exemplary embodiment of the present application;

[0024] Figure 5 A structural block diagram of a model fitting device provided for an exemplary embodiment of the present application;

[0025] Figure 6 A flowchart of the steps of a device for determining strain bearing capacity provided for an exemplary embodiment of the present application;

[0026] Figure 7 A schematic structural diagram of an electronic device provided for an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0028] In the scenario of determining the bearing capacity of the weld of the pipeline, for the fracture assessment method of the pipeline girth weld joint, the relevant technologies mainly include the FAD method (Failure Assessment Diagram) and the strain capacity prediction model method. Among them, the FAD failure assessment diagram method is to obtain the assessment conclusion by introducing the structural elastic fracture parameters and limit states, and after the crack driving force and load are dimensionless, the assessment conclusion is obtained by determining the mutual position relationship between the assessment point and the failure assessment curve. This method is simple and convenient to calculate and operate, but the assessment conclusion is often overly conservative. The strain capacity prediction model combines the crack propagation driving force and the material fracture toughness / toughness resistance curve to determine the limit state of the cracked structure and compare it with the engineering strain demand, and finally determine the assessment result. In addition, the relevant technology also proposes a prediction model for the strain bearing capacity of pipeline welded joints, but these models are only applicable to girth weld joints under high-strength matching conditions, and the scope of application of these prediction models cannot cover pipelines of various sizes.

[0029] Based on the above problems, the present application determines the geometric partitions of the girth weld joint based on the preset metallographic diagram of the girth weld joint, selects the material constitutive model of each partition, and establishes a finite element model of the girth weld joint, wherein the material properties of different geometric partitions are different, and the fusion line position of the girth weld joint contains an inner surface crack; based on the crack driving force curve under different combination conditions obtained by finite element calculation of the finite element model, the influence of geometric parameters, material parameters and load parameters on the crack driving force of the girth weld joint is quantitatively analyzed, and the key parameters with preset influence are determined; based on the crack driving force curve, the bearing strain of the cracked girth weld joint under different fracture toughness values ​​is obtained; nonlinear fitting analysis is performed on the bearing strain and key parameters to obtain a prediction model for the strain bearing capacity of the girth weld joint, and the prediction model is used to determine the bearing strain of the girth weld joint, and a prediction model for the strain bearing capacity of the pipeline girth weld joint with a wide range of applications can be obtained, which can provide guidance for the design and integrity evaluation of pipelines of various specifications.

[0030] In this embodiment, the model fitting method and the strain bearing capacity determination method can be an overall model fitting method implemented with the help of a cloud computing system. In addition, the server that executes the model fitting method can be a cloud server, so as to run various algorithms with the advantage of cloud resources; relative to the cloud, the model fitting method can also be applied to a conventional server or server array or other server-side device or terminal device, which is not limited here.

[0031] In addition, an application scenario of the embodiment of the present application is as follows Figure 1 , Figure 1 The pipeline 11 and the pipeline 12 are connected by welding, and a girth weld joint 13 is generated after welding. Wherein, X is an enlarged view of the girth weld joint 13, including: a weld area 131, a heat-affected zone 132, and a base material area 133 of the pipeline. The model fitting method of the embodiment of the present application can fit a prediction model and accurately predict the strain bearing capacity of girth weld joints 13 of various specifications.

[0032] also, Figure 1 This is just an exemplary application scenario, and the embodiment of the present application can be applied to any scenario of girth welding between pipes. The embodiment of the present application does not limit the specific application scenario.

[0033] Figure 2 A flow chart of the steps of a model fitting method provided by an exemplary embodiment of the present application. Figure 2 The model fitting method shown specifically includes the following steps:

[0034] S201, based on the preset metallographic diagram of the girth weld joint, determine the geometric partitions of the girth weld joint, select the material constitutive model of each partition, and establish a finite element model of the girth weld joint.

[0035] Among them, the material properties of different geometric partitions are different, and the fusion line of the girth weld joint contains an inner surface crack. Furthermore, the girth weld joint is a girth weld joint used for model fitting, and the preset metallographic diagram of the girth weld joint is obtained by pre-testing. The partition of the girth weld joint is as follows Figure 1 As shown, it includes: weld area, heat affected zone and base material area.

[0036] Further, the preset metallographic image may be a macroscopic metallographic image of a girth weld joint welded by a fully automatic welding process.

[0037] Among them, the material constitutive model of the parent material area can be determined by fitting the CSA Z662 standard stress-strain curve equation recommended by the engineering project. The specific expression formula of the material constitutive model of the parent material area is as shown in Formula 1):

[0038]

[0039] In formula 1), ε1 is the strain corresponding to the parent material area, σ1 is the stress corresponding to the parent material area, the unit is MPa, E1 is the elastic modulus of the parent material area, the unit is MPa, σ y1 is the material yield strength of the parent material area, in MPa, n is the material hardening coefficient of the parent material area, and λ1 is the yield strength ratio of the parent material. Among them, the material of the parent material area is known, which is the material of the pipe to which the girth weld belongs (referred to as pipe material), and the material hardening coefficient n and material yield strength ratio λ1 of the parent material area are known.

[0040] Among them, the material hardening coefficient in formula 1)

[0041] Furthermore, the strength matching parameters recommended by the CSA Z662 standard are used as the strength matching coefficient of the weld zone, wherein the strength matching coefficient of the weld zone is the ratio of the weld tensile strength to the base material tensile strength. Then the strength matching coefficient of the weld zone is known, and the base material tensile strength refers to the tensile strength of the pipe, which is also known. Then, the weld tensile strength can be determined by the strength matching coefficient of the weld zone and the base material tensile strength. In the embodiment of the present application, according to the statistics of the tensile test of the full weld metal round bar of the China-Russia East Line X80 pipeline, the uniform elongation of the material is about 4.5%, the distribution range of the yield strength and the tensile strength is linearly related, and the formula 2) used to represent the material constitutive model of the weld zone is fitted and determined, as follows:

[0042]

[0043] In formula 2), ε2 is the strain corresponding to the weld area, σ2 is the stress corresponding to the weld area, the unit is MPa, E2 is the elastic modulus of the weld area, the unit is MPa, σ y2is the material yield strength of the weld zone, in MPa, and n2 is the material hardening coefficient of the weld zone.

[0044] Furthermore, it is assumed that the heat affected zone and the base material zone have the same hardening coefficient and yield strength ratio, and the softening rate of the heat affected zone is determined as shown in Formula 3), which is as follows:

[0045]

[0046] In formula 3), μ is the softening index, which is a known value, and σ t3 is the tensile strength of the heat affected zone, in MPa, σ t1 If the tensile strength of the pipe in the base material area is t3 =(1-μ)*σ t1 .

[0047] Based on the tensile strength σ of the heat affected zone determined tHAZ , the CSA Z662 standard stress-strain curve equation is also used to determine the material constitutive model of the heat-affected zone. Among them, the material constitutive model of the heat-affected zone is expressed in the formula (4), which is as follows:

[0048]

[0049] In formula 4), ε3 is the strain corresponding to the heat affected zone, σ3 is the stress corresponding to the heat affected zone, the unit is MPa, E3 is the elastic modulus of the heat affected zone, the unit is MPa, σ y3 is the material yield strength of the heat affected zone, in MPa, n3 is the material hardening coefficient of the heat affected zone, and λ3 is the yield strength ratio of the heat affected zone. The material hardening coefficient n3 and yield strength ratio λ3 of the heat affected zone are consistent with those of the parent material.

[0050] Among them, the material hardening coefficient in formula 4)

[0051] S202, based on the crack driving force curves under different combination conditions obtained by finite element calculation of the finite element model, quantitatively analyze the influence of geometric parameters, material parameters and load parameters on the crack driving force of the girth weld joint, and determine the key parameters with preset influence.

[0052] By performing finite element analysis on the geometric partitions and selecting the material constitutive model of each partition, a finite element model can be established, wherein crack driving force curves of cracks of different specifications can be obtained when the finite element analysis is performed.

[0053] In an embodiment of the present application, there is an inner surface crack at the fusion line of the girth weld joint. The crack tip opening displacement is determined by analysis. The crack tip opening displacement automatic extraction program pre-developed in the programming language Python can be used to select the 45° intercept method to determine the tip opening displacement of each crack.

[0054] Among them, the influence of the geometric parameters, material parameters and load of the girth weld joint on the crack driving force of the girth weld joint is quantitatively analyzed, and then the key parameters with preset influence are determined. Among them, the preset influence can be a key parameter with a greater influence. Among them, the geometric parameters quantitatively analyzed include pipe diameter, wall thickness, crack depth, crack length and girth weld joint misalignment. The material parameters quantitatively analyzed include the material yield strength σ of the parent material area y , parent material yield strength ratio λ1, weld strength matching coefficient m, stress-strain curve form of each partition, softening rate μ of heat-affected zone. Load parameters may include distal strain and pipeline internal pressure. After quantitative analysis of these geometric parameters, material parameters and load parameters, it is determined that the key parameters that have a greater impact on the crack driving force of the girth weld joint include: girth weld joint misalignment h, crack depth a, crack length 2c, weld strength matching coefficient m and parent material yield strength ratio λ1. Furthermore, key parameters may also include distal strain and pipeline internal pressure.

[0055] S203, based on the crack driving force curve, obtaining the bearing strain of the cracked girth weld joint at different fracture toughness values.

[0056] In an embodiment of the present application, the fracture toughness value of the girth weld joint of the pipeline can be between 0.1 mm and 2 mm. Five groups of fracture toughness corresponding crack driving forces can be equally spaced on the preset driving force curve of each crack as the bearing strain corresponding to the training toughness value, and a data analysis library for the bearing strain of the girth weld joint of the pipeline can be constructed.

[0057] S204, performing nonlinear fitting analysis on the bearing strain and key parameters to obtain a prediction model for the strain bearing capacity of the girth weld joint.

[0058] Among them, the prediction model is used to determine the load-bearing strain of the girth weld joint.

[0059] In an optional embodiment, a nonlinear fitting analysis is performed on the bearing strain and key parameters to obtain a prediction model for the strain bearing capacity of the girth weld joint, including:

[0060] The prediction model is obtained using the following formula 5):

[0061] TSC0=f1(h,a,c,m,λ1)×δ+f2(h,a,c,m,λ2) Formula 5)

[0062] In the above formula, TSC0 represents the bearing strain, which is used to represent the strain bearing capacity of the girth weld joint; f1 is the first fitting function of the girth weld joint misalignment h, crack depth a, crack length 2c, and weld strength matching coefficient m; f2 is the second fitting function of the girth weld joint misalignment h, crack depth a, crack length 2c, and weld strength matching coefficient m, wherein the girth weld joint misalignment h, crack depth a, and crack length 2c are the geometric parameters of the girth weld joint, and the weld strength matching coefficient m, the pipe yield strength ratio λ2, and the fracture toughness δ are the material parameters of the girth weld joint.

[0063] Further, f1 and f2 are determined using the following formula:

[0064]

[0065]

[0066] In the above formula, μ1~μ 13 , α1~α 13 is the fitting coefficient.

[0067] In the embodiment of the present application, formula 5) is determined by a fitting algorithm and can be applied to girth welding joints of pipes of various sizes and specifications, and has a wide range of applications.

[0068] In an optional embodiment, after obtaining the prediction model of the strain bearing capacity of the girth weld joint, the influence of the wall thickness (t) and the internal pressure (p) on the strain bearing capacity of the girth weld joint is considered, wherein the influence of the internal pressure (p) is considered as the ratio of the hoop stress caused by the internal pressure to the yield strength σ of the parent material zone. y The ratio f p , further, the following formula 6) is used to modify the prediction model to obtain the final prediction model:

[0069] TSC pt =TSC0*k(t)*g(f p ) Formula 6)

[0070] In formula 6), k(t) is the correction factor of the pipe wall thickness on the girth weld strain, pipe is the pipe to which the girth weld joint belongs, g(f p ) is the correction factor of the internal pressure of the pipeline on the strain force of the girth weld.

[0071] Furthermore, k(t) and g(f p ) is determined using the following formula:

[0072]

[0073] Among them, β1~β7, ξ1~ξ4 are fitting coefficients, and t is the wall thickness of the pipe.

[0074] Further, the parameters of the test ring weld joint shown in Table 1 are used to predict the strain bearing capacity of the prediction model of the embodiment of the present application, wherein CTOD in Table 1 represents the crack tip opening displacement, and the parameters of the test ring weld joint in Table 1 are respectively input into the existing prediction model A of strain bearing capacity, the prediction model B of strain bearing capacity, and the prediction model obtained by fitting in the embodiment of the present application, and the prediction results of each model are as follows: Figure 3 ,in, Figure 3 In the above, the strain bearing capacity test value is the true value of the bearing strain of the corresponding girth weld joint, and the strain bearing capacity prediction value is the predicted value of the bearing strain of the girth weld joint using the corresponding prediction model. Figure 3 It can be determined that the average absolute error of the prediction results of the strain bearing capacity prediction model A is 1.22%, and the average relative error is 90%. The average absolute error of the prediction results of the strain bearing capacity prediction model B is 0.50%, and the average relative error is 45%. The average absolute error of the prediction results of the prediction model fitted in the present application is 0.29%, and the average relative error is 15%. It can be seen that the prediction model of the present application has higher accuracy and considers a wider range of parameter variations, which also makes up for the deficiency that the existing girth weld strain bearing capacity prediction model cannot be applied to low-strength matching conditions of welds.

[0075] Table 1

[0076]

[0077]

[0078] In summary, firstly, the embodiment of the present application constructs a finite element model for a cracked pipe girth weld joint and simulates its strain response, thereby obtaining a prediction model that can predict the strain bearing capacity of the pipe girth weld joint. Secondly, in the embodiment of the present application, the calculation condition parameters have a wide range of values, which can make up for the shortcomings of the existing girth weld joint strain bearing capacity calculation method, which has incomplete parameter range coverage and cannot consider the girth weld matching conditions. Finally, the embodiment of the present application uses a high-performance information processing system as an auxiliary equipment, which is in line with the direction of scientific and technological development. The finite element method accurately simulates the mechanical response of the pipe girth weld joint containing crack defects under load, making up for the shortcomings of the existing FAD failure assessment diagram method that the evaluation results are too conservative.

[0079] Further, based on the above embodiments, the present application embodiment provides a method for determining strain bearing capacity, referring to Figure 4 , specifically including the following steps:

[0080] S401, obtaining target parameters of a target girth welding joint.

[0081] The target parameters include: target geometric parameters, target material parameters and target load parameters of the target girth weld joint.

[0082] Specifically, the target girth weld joint is the girth weld joint to be predicted, the target geometric parameters include: target girth weld joint misalignment, crack depth, crack length, target material parameters include weld strength matching coefficient, pipe yield ratio, fracture toughness, and target load parameters include distal strain and pipeline internal pressure.

[0083] S402, inputting the target parameters into the prediction model for analysis to obtain the target girth weld joint bearing strain value.

[0084] Among them, the bearing strain value represents the strain bearing capacity of the target girth weld joint, and the prediction model is determined by using the above-mentioned model fitting method.

[0085] Substitute the above target geometric parameters and target material parameters into formula 5) to obtain the target girth weld joint bearing strain value. If the wall thickness and internal pressure of the target girth weld joint are taken into account, the wall thickness and internal pressure and the result calculated by formula 5) are input into formula 6) to obtain the final bearing strain value to indicate the strain bearing capacity of the target girth weld joint.

[0086] Furthermore, after inputting the target parameters into the prediction model for analysis and obtaining the target girth weld joint bearing strain value, it also includes: determining the difference between the bearing strain value and the preset strain threshold; if the difference is greater than 0, determining that the target girth weld joint is in a safe state.

[0087] In the embodiment of the present application, the preset strain threshold can select 0.5% engineering strain. When the determined bearing strain value is greater than the preset strain threshold, the target girth weld joint is in a safe state. When the determined bearing strain value is equal to the preset strain threshold, the target girth weld joint is in a critical state, and when the determined bearing strain value is less than the preset strain threshold, the target girth weld joint is in a dangerous state, that is, it does not meet the pipeline safety operation requirements.

[0088] The embodiment of the present application provides a method for calculating the strain bearing capacity of a girth weld joint of a pipeline considering the low matching of the weld. Using a high-performance information processing system deployed on a server or terminal device as an auxiliary device, the finite element method is used to simulate the mechanical response of a girth weld joint of a pipeline containing crack defects under load. Based on the analysis of factors including geometric dimensions, material characteristics, and the influence of loads on the crack driving force, a prediction model for the strain bearing capacity of a girth weld joint of a pipeline is proposed based on the crack initiation failure criterion, and the applicability of the girth weld joint is evaluated by comparing it with a preset strain threshold.

[0089] In the embodiments of this application, refer to Figure 5 In addition to providing a model fitting method, a model fitting device 50 is also provided for executing the above-mentioned model fitting method; the model fitting device 50 comprises:

[0090] A construction module 51 is used to determine the geometric partitions of the girth weld joint based on a preset metallographic diagram of the girth weld joint, select a material constitutive model for each partition, and establish a finite element model of the girth weld joint, wherein the material properties of different geometric partitions are different, and the fusion line of the girth weld joint contains an inner surface crack;

[0091] An analysis module 52 is used to determine the crack driving force curves under different combination conditions obtained by finite element calculation based on the finite element model, quantitatively analyze the influence of geometric parameters, material parameters and load parameters on the crack driving force of the girth weld joint, and determine the key parameters with preset influences;

[0092] An acquisition module 53 is used to acquire the bearing strain of the cracked girth weld joint at different fracture toughness values ​​based on the crack driving force curve;

[0093] The fitting module 54 is used to perform nonlinear fitting analysis on the bearing strain and key parameters to obtain a prediction model of the strain bearing capacity of the girth weld joint. The prediction model is used to determine the bearing strain of the girth weld joint.

[0094] In an optional embodiment, the fitting module 54 is specifically used to: obtain a prediction model using the following formula: TSC0=f1(h,a,c,m,λ1)×δ+f2(h,a,c,m,λ2); in the above formula, TSC0 represents the bearing strain, f1 is the first fitting function of the girth weld joint misalignment h, crack depth a, crack length 2c, and weld strength matching coefficient m; f2 is the second fitting function of the girth weld joint misalignment h, crack depth a, crack length 2c, and weld strength matching coefficient m, wherein the girth weld joint misalignment h, crack depth a, and crack length 2c are geometric parameters of the girth weld joint, and the weld strength matching coefficient m, the pipe yield ratio λ2, and the fracture toughness δ are material parameters of the girth weld joint.

[0095] In an optional embodiment, f1 and f2 are determined using the following formula:

[0096]

[0097] In the above formula, μ1~μ 13 , α1~α 13 is the fitting coefficient.

[0098] In an optional embodiment, a correction module (not shown) is further included, which is used to correct the prediction model after obtaining the prediction model of the strain bearing capacity of the girth weld joint by using the following formula to obtain the final prediction model: TSC pt =TSC0*k(t)*g(f p ); In the above formula, k(t) is the correction factor of the wall thickness of the pipe on the strain of the girth weld, the pipe is the pipe to which the girth weld joint belongs, and g(fp ) is the correction factor of the internal pressure of the pipeline on the strain force of the girth weld.

[0099] In an optional embodiment, k(t) and g(f p ) is determined using the following formula:

[0100]

[0101] Among them, β1~β7, ξ1~ξ4 are fitting coefficients.

[0102] The model fitting device provided in the present application can obtain a widely applicable prediction model for the strain bearing capacity of pipeline girth weld joints.

[0103] In the embodiment of the present application, a strain bearing capacity determination device 60 is also provided, referring to Figure 6 , the strain bearing capacity determining device 60 comprises:

[0104] An acquisition module 61 is used to acquire target parameters of a target girth weld joint, wherein the target parameters include: target geometric parameters, target material parameters and target load parameters of the target girth weld joint;

[0105] The analysis module 62 is used to input the target parameters into the prediction model for analysis to obtain the target girth weld joint bearing strain value, which represents the strain bearing capacity of the target girth weld joint. The prediction model is determined by the above-mentioned model fitting method.

[0106] An optional embodiment further includes a safety determination module (not shown) for determining the difference between the load-bearing strain value and a preset strain threshold; if the difference is greater than 0, it is determined that the target girth weld joint is in a safe state.

[0107] The strain bearing capacity determination device provided in the present application can accurately predict the strain bearing capacity of pipeline girth weld joints of various sizes and specifications.

[0108] In addition, in some of the processes described in the above embodiments and the accompanying drawings, multiple operations that appear in a specific order are included, but it should be clearly understood that these operations may not be executed in the order in which they appear in this article or executed in parallel, and are only used to distinguish between different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations may be executed in sequence or in parallel. It should be noted that the descriptions of "first", "second", etc. in this article are used to distinguish different messages, devices, modules, etc., do not represent the order of precedence, and do not limit the "first" and "second" to different types.

[0109] Figure 7 This is a schematic diagram of the structure of an electronic device provided by an exemplary embodiment of the present application. Figure 7 As shown, the electronic device 70 includes: a processor 71, and a memory 72 communicatively connected to the processor 71, and the memory 72 stores computer-executable instructions.

[0110] Among them, the processor executes the computer execution instructions stored in the memory to implement the model fitting method or strain bearing capacity determination method provided by any of the above method embodiments, and the specific functions and technical effects that can be achieved are not repeated here.

[0111] An embodiment of the present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the model fitting method or strain bearing capacity determination method provided in any of the above method embodiments.

[0112] An embodiment of the present application also provides a computer program product, which includes: a computer program, which is stored in a readable storage medium, and at least one processor of an electronic device can read the computer program from the readable storage medium, and at least one processor executes the computer program so that the electronic device executes the model fitting method or strain bearing capacity determination method provided in any of the above method embodiments.

[0113] In the several embodiments provided in the present application, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of systems or units, which can be electrical, mechanical or other forms.

[0114] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0115] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0116] The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium. The above-mentioned software functional unit is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to perform some steps of the methods of each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), disk or optical disk and other media that can store program codes.

[0117] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example for illustration. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the system is divided into different functional modules to complete all or part of the functions described above. The specific working process of the system described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0118] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0119] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A model fitting method, characterized in that: include: Based on the preset metallographic diagram of the girth weld joint, the geometric partitions of the girth weld joint are determined, and the material constitutive model of each partition is selected to establish a finite element model of the girth weld joint, wherein the material properties of different geometric partitions are different, and the fusion line position of the girth weld joint contains an inner surface crack; Based on the crack driving force curves under different combination conditions obtained by finite element calculation of the finite element model, quantitatively analyzing the influence of geometric parameters, material parameters and load parameters on the crack driving force of the girth weld joint, and determining key parameters with preset influences; Based on the crack driving force curve, the bearing strain of the cracked girth weld joint at different fracture toughness values ​​is obtained; Performing nonlinear fitting analysis on the bearing strain and the key parameters to obtain a prediction model of the strain bearing capacity of the girth weld joint, wherein the prediction model is used to determine the bearing strain of the girth weld joint; The nonlinear fitting analysis of the bearing strain and the key parameters is performed to obtain a prediction model of the strain bearing capacity of the girth weld joint, including: The prediction model is obtained using the following formula: TSC0=f1(h,a,c,m,λ1)×δ+f2(h,a,c,m,λ2); In the above formula, TSC0 represents the bearing strain, which is used to represent the strain bearing capacity of the girth weld joint; f1 is the first fitting function of the girth weld joint misalignment h, crack depth a, crack length 2c, weld strength matching coefficient m and parent material yield strength ratio λ1; f2 is the second fitting function of the girth weld joint misalignment h, crack depth a, crack length 2c, weld strength matching coefficient m and parent material yield strength ratio λ1, wherein the girth weld joint misalignment h, crack depth a, crack length 2c are geometric parameters of the girth weld joint, and the weld strength matching coefficient m, pipe yield strength ratio λ2, and fracture toughness δ are material parameters of the girth weld joint; Among them, f1 and f2 are determined by the following formula; In the above formula, μ1~μ 13 , α1~α 13 is the fitting coefficient.

2. The model fitting method according to claim 1, characterized in that: After obtaining the prediction model of the strain bearing capacity of the girth weld joint, it also includes: The prediction model is modified using the following formula to obtain the final prediction model: TSC pt =TSC0*k(t)*g(f p ); In the above formula, TSC pt The final bearing strain, k(t) is the correction factor of the wall thickness of the pipeline to the girth weld strain, the pipeline is the pipeline to which the girth weld joint belongs, g(f p ) is the correction factor of the internal pressure of the pipeline on the strain force of the girth weld.

3. The model fitting method according to claim 2, characterized in that: in, k(t) and g(f p ) is determined using the following formula: Among them, β1~β7, ξ1~ξ4 are fitting coefficients, t is the wall thickness of the pipe, and f p is the hoop stress caused by the internal pressure (p) and the yield strength of the parent material area σ y ratio.

4. A method for determining strain bearing capacity, characterized in that: include: Acquire target parameters of a target girth weld joint, wherein the target parameters include: target geometric parameters, target material parameters, and target load parameters of the target girth weld joint; The target parameters are input into the prediction model for analysis to obtain the target girth weld joint bearing strain value, wherein the bearing strain value represents the strain bearing capacity of the target girth weld joint. The prediction model is determined by the model fitting method described in any one of claims 1 to 3.

5. The method for determining strain bearing capacity according to claim 4, characterized in that: After the target parameters are input into the prediction model for analysis to obtain the target girth weld joint bearing strain value, the method further includes: Determining a difference between the load-bearing strain value and the preset strain threshold; If the difference is greater than 0, it is determined that the target girth weld joint is in a safe state.

6. A model fitting device, characterized in that: include: A construction module is used to determine the geometric partitions of the girth weld joint based on a preset metallographic diagram of the girth weld joint, select a material constitutive model for each partition, and establish a finite element model of the girth weld joint, wherein the material properties of different geometric partitions are different, and the fusion line position of the girth weld joint contains an inner surface crack; An analysis module, for quantitatively analyzing the influence of geometric parameters, material parameters and load parameters on the crack driving force of the girth weld joint based on the crack driving force curves under different combination conditions obtained by finite element calculation of the finite element model, and determining key parameters with preset influences; An acquisition module, used for acquiring the bearing strain of the cracked girth weld joint at different fracture toughness values ​​based on the crack driving force curve; A fitting module, used for performing nonlinear fitting analysis on the bearing strain and the key parameters to obtain a prediction model of the strain bearing capacity of the girth weld joint, wherein the prediction model is used to determine the bearing strain of the girth weld joint; The acquisition module is specifically used for: The prediction model is obtained using the following formula: TSC0=f1(h,a,c,m,λ1)×δ+f2(h,a,c,m,λ2); In the above formula, TSC0 represents the bearing strain, which is used to represent the strain bearing capacity of the girth weld joint; f1 is the first fitting function of the girth weld joint misalignment h, crack depth a, crack length 2c, weld strength matching coefficient m and parent material yield strength ratio λ1; f2 is the second fitting function of the girth weld joint misalignment h, crack depth a, crack length 2c, weld strength matching coefficient m and parent material yield strength ratio λ1, wherein the girth weld joint misalignment h, crack depth a, crack length 2c are geometric parameters of the girth weld joint, and the weld strength matching coefficient m, pipe yield strength ratio λ2, and fracture toughness δ are material parameters of the girth weld joint; Among them, f1 and f2 are determined by the following formula; In the above formula, μ1~μ 13 , α1~α 13 is the fitting coefficient.

7. A device for determining strain bearing capacity, characterized in that: include: An acquisition module, used to acquire target parameters of a target girth weld joint, wherein the target parameters include: target geometric parameters, target material parameters and target load parameters of the target girth weld joint; An analysis module is used to input the target parameters into a prediction model for analysis to obtain the target girth weld joint bearing strain value, wherein the bearing strain value represents the strain bearing capacity of the target girth weld joint, and the prediction model is determined by the model fitting method described in any one of claims 1 to 3.

8. An electronic device, characterized in that: include: A processor, a memory, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the model fitting method according to any one of claims 1 to 3 or the strain bearing capacity determination method according to claim 4 or 5 is implemented.

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