Probabilistic residual life prediction method and system for defective welded structures

Abstract

The present invention belongs to the technical field of life prediction of welding structures, and provides a method and system for predicting the probabilistic remaining life of a defective welding structure. The method includes constructing a global finite element model of the defective welding structure and a sub-finite element model of key parts based on the load conditions of the defective welding structure and the quantified and regularized defect forms, calculating the current stress field intensity factor; obtaining the threshold value of the stress field intensity factor of the defective welding structure based on the fracture mechanics test and the critical defect length of the defective welding structure based on the damage mechanics test; comparing the current stress field intensity factor with the threshold value of the stress field intensity factor: if the former is less than the latter, the defect is safe; otherwise, based on the relationship between the operating mileage and the defect length, when the defect length reaches the critical defect length, the operating mileage is the remaining life of the defective welding structure under the set survival rate. It improves the accuracy of the probabilistic remaining life prediction.

Description

Technical Field

[0001] The present invention belongs to the technical field of welding structure life prediction, and in particular relates to a method and system for predicting the probabilistic remaining life of a defective welding structure. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] With the increase in the operating mileage of rail transit vehicles (such as EMUs and urban rail vehicles), there is an increasing demand for safety assessment of operation and maintenance structures. Accurate evaluation of the remaining life of the structure is the key to conducting safety assessment of operation and maintenance. At present, the main load-bearing structures of rail transit vehicles, the car body chassis and bogies, are large metal welded structures. The welded joints are located at the connection of the structure, with irregular geometric morphology and natural stress concentration. The welded joints and their heat-affected zones have complex distribution of residual stress, and their fatigue resistance is weaker than that of the parent material. Therefore, the failure of welded structures often occurs in the welded joints and their heat-affected zones. The remaining life assessment of welded joints can achieve the management of the life of welded structures.

[0004] Although strict processes and standards are used to control the welding quality of welding structures in the process and production, defects and damage are still inevitable during the production, assembly and operation and maintenance. The inventors found that in the existing probabilistic remaining life prediction process of defective welded structures, there is a problem of modeling difficulty in the crack mechanics finite element analysis of the defective welded structures, and the influence of random vibration on the crack propagation of the welded structure is not considered, which reduces the accuracy of the probabilistic remaining life prediction. Summary of the invention

[0005] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a probabilistic remaining life prediction method and system for a defective welded structure, which performs sub-finite element modeling on the key parts of the defective welded structure, takes into account the influence of random vibration on the crack propagation of the welded structure, is closer to the actual dynamic operation situation of the structure, and improves the accuracy of the probabilistic remaining life prediction.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A first aspect of the present invention provides a method for predicting the probabilistic remaining life of a defective welded structure, comprising:

[0008] Based on the load conditions of the defective welded structure and the quantified and regularized defect forms, a global finite element model of the defective welded structure and sub-finite element models of key parts are constructed to calculate the current stress field intensity factor;

[0009] Obtain the threshold value of stress field intensity factor of defective welded structure based on fracture mechanics test and the critical defect length of defective welded structure based on damage mechanics test;

[0010] Compare the current stress field intensity factor with the stress field intensity factor threshold:

[0011] If the former is less than the latter, the defect is safe; otherwise, based on the relationship between operating mileage and defect length, when the defect length reaches the critical defect length, the operating mileage is the remaining life of the defective welded structure under the set survival rate.

[0012] A second aspect of the present invention provides a probabilistic remaining life prediction system for a defective welded structure, comprising:

[0013] The first calculation module is used to construct a global finite element model of the defective welded structure and a sub-finite element model of key parts based on the load condition of the defective welded structure and the quantified and regularized defect form, and calculate the current stress field intensity factor;

[0014] A second calculation module is used to obtain a stress field intensity factor threshold value of a defective welded structure based on a fracture mechanics test and a critical defect length of a defective welded structure based on a damage mechanics test;

[0015] The remaining life prediction module is used to compare the current stress field intensity factor with the stress field intensity factor threshold value:

[0016] If the former is less than the latter, the defect is safe; otherwise, based on the relationship between operating mileage and defect length, when the defect length reaches the critical defect length, the operating mileage is the remaining life of the defective welded structure under the set survival rate.

[0017] A third aspect of the present invention is to provide an electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, to implement the steps in the above-mentioned method for predicting the probabilistic remaining life of a defective welded structure.

[0018] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the method for predicting the probabilistic remaining life of a defective welded structure as described above.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] Based on the load conditions of the defective welded structure and the quantified and regularized defect forms, the present invention constructs a global finite element model of the defective welded structure and sub-finite element models of key parts, calculates the current stress field intensity factor, and performs sub-finite element modeling on the key parts of the defective welded structure. The influence of random vibration on the crack propagation of the welded structure is considered, and the stress field intensity factor threshold value of the defective welded structure based on the fracture mechanics test and the critical defect length of the defective welded structure based on the damage mechanics test are obtained, which is closer to the actual dynamic operation situation of the structure and improves the accuracy of the probabilistic remaining life prediction.

[0021] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0023] Figure 1 is a schematic diagram of a system architecture of an exemplary application environment of a method for predicting the probabilistic remaining life of a defective welded structure according to an embodiment of the present invention;

[0024] Figure 2 This is a flow chart of a method for predicting the probabilistic remaining life of a defective welded structure according to an embodiment of the present invention;

[0025] Figure 3 is a schematic diagram of a global finite element model and a sub-finite element model of an embodiment of the present invention;

[0026] FIG4 (a) is a defect regularization example 1 of an embodiment of the present invention;

[0027] FIG4( b ) is a defect regularization example 2 of an embodiment of the present invention;

[0028] Figure 5 is a critical defect size determination process of an embodiment of the present invention;

[0029] Figure 6 2 is a schematic diagram of the structure of a probabilistic remaining life prediction system for a defective welded structure according to an embodiment of the present invention;

[0030] Figure 7 The figure is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0032] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0034] Figure 1 A schematic diagram of a system architecture of an exemplary application environment in which the probabilistic remaining life prediction method for a defective welded structure according to an embodiment of the present invention can be applied is shown.

[0035] like Figure 1 As shown, system architecture 100 may include electronic device 101 and / or electronic device 102, network 103 and server 104. Network 103 is used to provide a medium for communication links between electronic device 101, electronic device 102 and server 104. Network 103 may include various connection types, such as wired, wireless communication links or optical fiber cables, etc. Electronic devices 101 and 102 include but are not limited to desktop computers, portable computers, smart phones, and tablet computers, etc. It should be understood that Figure 1 The number of electronic devices, networks and servers in the embodiment is only for illustration. Any number of electronic devices, networks and servers may be provided as required. For example, the server 104 may be a server cluster composed of multiple servers.

[0036] The probabilistic remaining life prediction method for a defective welded structure provided in the embodiment of the present invention is generally executed by the server 104, and accordingly, the probabilistic remaining life prediction system for a defective welded structure may be disposed in the server 104. However, it is easy for a person skilled in the art to understand that the probabilistic remaining life prediction method for a defective welded structure provided in the embodiment of the present invention may also be executed by the electronic device 101 or the electronic device 102.

[0037] Embodiment 1

[0038] Reference Figure 2 This embodiment provides a method for predicting the probabilistic remaining life of a defective welded structure, which specifically includes the following steps:

[0039] S101: Based on the load conditions of the defective welded structure and the quantified and regularized defect forms, a global finite element model of the defective welded structure and sub-finite element models of key parts are constructed to calculate the current stress field intensity factor.

[0040] The stress field intensity factor at the crack front is calculated by the crack tip opening displacement. The specific calculation formula is:

[0041]

[0042] Where E is the material parameter, B is the plate thickness, and V is the opening displacement at a distance r from the crack tip. Both V and r can be obtained by the finite element method.

[0043] In the specific implementation, the load condition of the defective welded structure refers to the road spectrum, which refers to the track pavement spectrum, which refers to the power spectrum density curve of the road surface roughness. The track pavement roughness as the vibration input of the rail transit vehicle mainly uses the displacement power spectrum density to describe its statistical characteristics, and the time history of the track pavement roughness can be regarded as a stationary random process.

[0044] Specifically, for the main load-bearing structures, such as the frame and the underframe, it is also necessary to clarify the constraints, loads and load occurrence frequency. ; For the installation structure, consider its dynamic response characteristics and obtain the characteristic dynamic stress and occurrence frequency of the analysis position The defect forms are counted and quantified, and the defects such as undercut, lack of penetration and macro cracks are geometrically quantified. f i It represents the i-th load form, N i It represents the frequency of occurrence of this load form.

[0045] The contour and form of the real defect are irregular. In fracture mechanics analysis, the irregular defects must be regularized. For embedded defects, they are regularized into elliptical cracks, and for surface defects, they are regularized into semi-elliptical cracks. As shown in Figure 4 (a) and Figure 4 (b), the longest characteristic length of the defect is selected as the major axis of the ellipse. , select the longest characteristic length perpendicular to the major axis as the minor axis of the ellipse ( ), regularization follows the conservative principle.

[0046] Specifically, in the process of regularizing defect forms, embedded defects are regularized into elliptical cracks, and surface defects are regularized into semi-elliptical cracks.

[0047] Figure 3 The global finite element model of the defective welded structure and the sub-finite element models of the key parts are given.

[0048] Among them, the key parts are the parts where defects have occurred in the welding structure and the parts that may appear artificially.

[0049] Specifically, the basic idea of ​​the sub-finite element model of the key parts is to obtain the displacement (force) of the sub-model boundary in the global model as the boundary condition of the sub-model, which solves the problem of complex or even impossible modeling in the fracture mechanics analysis of complex structures. Figure 3 As shown in the figure, the three-dimensional fracture mechanics finite element analysis requires that the mesh is all hexahedral or pentahedral units. The global model structure is complex and is made of thin plates welded together, so it is impossible to achieve full hexahedral or pentahedral unit modeling. The principle of sub-model selection is to facilitate the construction of the fracture mechanics model of the analysis part, and the error between the stress field of the key analysis part and the stress field of the global model is less than 5%.

[0050] In the process of calculating the current stress field intensity factor, the global finite element model of the defective welded structure is used as the boundary condition of the sub-finite element model of the key part.

[0051] S102: Obtaining a stress field intensity factor threshold value of a defective welded structure based on a fracture mechanics test and a critical defect length of a defective welded structure based on a damage mechanics test.

[0052] Four main parameters are obtained based on fracture mechanics tests (stress field intensity factor threshold), (crack growth rate coefficient), (crack growth rate index), (Fracture toughness) Gaussian distribution , , ,0, , , When evaluating the remaining life, select Data, the survival probability is 97.5%. Among them, is the nominal stress.

[0053] S103: Compare the current stress field intensity factor with the stress field intensity factor threshold value:

[0054] If the former is less than the latter, the defect is safe; otherwise, based on the relationship between operating mileage and defect length, when the defect length reaches the critical defect length, the operating mileage is the remaining life of the defective welded structure under the set survival rate.

[0055] Based on the load spectrum or stress spectrum and the Paris formula of the basic law of crack extension, the fracture mechanics parameters under the Gaussian distribution with positive two standard deviations are used, such as The relationship between operating mileage and defect length is calculated by using the fracture mechanics parameters; the standard deviation is the nominal stress, is the nominal stress.

[0056] like Figure 5 As shown, the process of obtaining the critical defect length is:

[0057] A failure assessment diagram is drawn based on the damage mechanics test, where the contour of the failure assessment diagram is determined by the material of the defective welded structure, the abscissa of the failure assessment diagram is Lr, and the ordinate is Kr, and both are functions of the defect length;

[0058] As the damage evolves, the reference stress and the stress field intensity factor increase simultaneously and eventually intersect with the contour line. The defect size at this time is the critical defect size.

[0059] exist Figure 5 In the equation, the horizontal axis is Lr and the vertical axis is Kr, where Lr= / σ s . is the reference stress, for a certain material, σ s To determine the value.

[0060] In a specific implementation, the reference stress and the normalized stress field intensity factor , both are defect lengths As the damage evolves, the reference stress and At the same time, it increases and finally intersects with the contour line. The defect size at this time is the critical defect size .

[0061]

[0062] in , Depends on the external load, is the ratio of crack length to plate thickness. From the formula, we can see that as the crack length increases, Increase.

[0063]

[0064] in is the material parameter, is the stress field intensity factor, , as the crack length increases, Increase; F is the shape factor. is the defect regularized to half of the minor axis of the ellipse, is the nominal stress.

[0065] For a material, and K mat are material parameters. It is a parameter that characterizes whether there is a risk of crack extension under fatigue load. K mat It is a parameter that characterizes whether a structure has the risk of failure or fracture under static load. is the current stress field intensity factor under fatigue load.

[0066] judge and ( ) relationship, such as < , then the defect is safe (97.5% probability). > , then based on the load spectrum or stress spectrum and the basic law of crack extension, the Paris formula ,use The relationship between the crack extension material parameters and the operating mileage defect length is calculated. The defect length reaches Hours, operating mileage It is the remaining life of the welded structure at a survival rate of 97.5%. Among them, C and m are constants, and n is the number of groups of load cycles converted from the load spectrum of the defective welded structure in a single load history.

[0067] In one or more embodiments, the method for predicting the probabilistic remaining life of a defective welded structure further includes:

[0068] Based on the fatigue failure test data of full-size welded joints, the relationship between operating mileage and defect length is corrected.

[0069] The full-size welded joints are required to have a width-to-thickness ratio greater than 6, a complete residual stress distribution, and a failure mode consistent with the structure. The number of tests is no less than 30 groups, and the damage evolution process is monitored by phased array and other methods to verify the conformity of the test data in the relationship model between operating mileage and defect length. Based on the test data, statistical methods are used to correct the relationship model between operating mileage and defect length.

[0070] Embodiment 2

[0071] Reference Figure 6 This embodiment provides a probabilistic remaining life prediction system for a defective welded structure, which specifically includes the following modules:

[0072] The first calculation module 201 is used to construct a global finite element model of the defective welded structure and a sub-finite element model of key parts based on the load condition of the defective welded structure and the quantified and regularized defect form, and calculate the current stress field intensity factor;

[0073] A second calculation module 202, which is used to obtain a stress field intensity factor threshold value of a defective welded structure based on a fracture mechanics test and a critical defect length of a defective welded structure based on a damage mechanics test;

[0074] The remaining life prediction module 203 is used to compare the current stress field intensity factor with the stress field intensity factor threshold value:

[0075] If the former is less than the latter, the defect is safe; otherwise, based on the relationship between operating mileage and defect length, when the defect length reaches the critical defect length, the operating mileage is the remaining life of the defective welded structure under the set survival rate.

[0076] In one or more embodiments, the probabilistic remaining life prediction system for a defective welded structure further includes:

[0077] A model correction module is used to correct the relationship between operating mileage and defect length based on fatigue failure test data of full-size welded joints.

[0078] It should be noted here that each module in this embodiment corresponds to each step in Example 1 one by one, and the specific implementation process is the same, which will not be repeated here.

[0079] Embodiment 3

[0080] A schematic diagram of the structure of an electronic device in this embodiment. It should be noted that: Figure 7 The electronic device 300 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0081] An electronic device of this embodiment includes a memory, a processor, and a computer program stored in the memory and executable on the processor, to implement the steps in the above-mentioned method for predicting the probabilistic remaining life of a defective welded structure.

[0082] like Figure 7As shown, the electronic device 300 includes a central processing unit (CPU) 301, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 302 or the program loaded from the storage part 508 to the random access memory (RAM) 303. In the RAM 303, various programs and data required for system operation are also stored. The central processing unit 301, the ROM 302 and the RAM 303 are connected to each other through a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0083] The following components are connected to the I / O interface 305: an input section 306 including a keyboard, a mouse, etc.; an output section 307 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 308 including a hard disk, etc.; and a communication section 309 including a network interface card such as a local area network (LAN) card, a modem, etc. The communication section 309 performs communication processing via a network such as the Internet. A drive 310 is also connected to the I / O interface 305 as needed. A removable medium 311, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 310 as needed, so that a computer program read therefrom is installed into the storage section 308 as needed.

[0084] Embodiment 4

[0085] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the steps in the method for predicting the probabilistic remaining life of a defective welded structure as described above are implemented.

[0086] According to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 309, and / or installed from the removable medium 311. When the computer program is executed by the central processing unit 301, various functions defined in the device of the present application are executed.

[0087] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products of the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of the processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for predicting the probabilistic remaining life of a defective welded structure, characterized in that: include: S101: Based on the load conditions of the defective welded structure and the quantified and regularized defect forms, a global finite element model of the defective welded structure and sub-finite element models of key parts are constructed to calculate the current stress field intensity factor; The load condition is a track pavement spectrum, which refers to a power spectrum density curve of pavement roughness; the quantification is specifically: geometric quantification of undercut, lack of penetration and macro crack defects; The key parts are parts of the welding structure where defects have occurred and parts that may appear artificially; In the global finite element model of the defective welded structure, the displacement of the sub-model boundary is obtained as the boundary condition of the sub-model; In the process of calculating the current stress field intensity factor, the global finite element model of the welded structure with defects is used as the boundary condition of the sub-finite element model of the key part; S102: Obtaining a stress field intensity factor threshold value of a defective welded structure based on a fracture mechanics test and a critical defect length of a defective welded structure based on a damage mechanics test; The process of obtaining the critical defect length is as follows: Based on the damage mechanics test, a failure assessment diagram is drawn. The contour of the failure assessment diagram is determined by the material of the defective welded structure. The horizontal coordinate of the failure assessment diagram is Lr, and the vertical coordinate is Kr, and both are functions of the defect length; where Lr= / σ s , is the reference stress, for a certain material, σ s To determine the value, the calculation formula of the reference stress is: ,in, , Depends on the external load, is the ratio of crack length to plate thickness; ,in, is the normalized stress field intensity factor, is the material parameter, is the stress field intensity factor, , F is the shape factor, is the defect regularized to half of the minor axis of the ellipse, is the nominal stress; As the damage evolves, the reference stress and the stress field intensity factor increase simultaneously and eventually intersect with the contour line. The defect size at this time is the critical defect size. S103: Compare the current stress field intensity factor with the stress field intensity factor threshold value: If the former is less than the latter, the defect is safe; otherwise, based on the relationship between the operating mileage and the defect length, when the defect length reaches the critical defect length, the operating mileage is the remaining life of the defective welded structure under the set survival rate; The relationship between the operating mileage and the defect length is calculated as follows: in, is the half of the minor axis of the ellipse regularized by the defect, n is the number of groups of load cycles converted from the load spectrum of the defective welded structure in a single load history, C is the crack growth rate coefficient, m is the crack growth rate index, is the current stress field intensity factor under fatigue load.

2. The method for predicting the probabilistic remaining life of a defective welded structure according to claim 1, wherein: The method for predicting the probabilistic remaining life of a defective welded structure further comprises: Based on the fatigue failure test data of full-size welded joints, the relationship between operating mileage and defect length is corrected.

3. The method for predicting the probabilistic remaining life of a defective welded structure according to claim 1, wherein: In the process of regularizing defect forms, embedded defects are regularized into elliptical cracks, and surface defects are regularized into semi-elliptical cracks.

4. The method for predicting the probabilistic remaining life of a defective welded structure according to claim 1, wherein: Based on the load spectrum or stress spectrum and the Paris formula of the basic law of crack propagation, the relationship between the operating mileage and the defect length is calculated using the fracture mechanics parameters under the positive two standard deviations of the Gaussian distribution.

5. The method for predicting the probabilistic remaining life of a defective welded structure according to claim 4, wherein: The standard deviation stated is the nominal stress.

6. A probabilistic remaining life prediction system for defective welded structures, characterized in that: include: The first calculation module is used to construct a global finite element model of the defective welded structure and a sub-finite element model of key parts based on the load condition of the defective welded structure and the quantified and regularized defect form, and calculate the current stress field intensity factor; The load condition is a track pavement spectrum, which refers to a power spectrum density curve of pavement roughness; the quantification is specifically: geometric quantification of undercut, lack of penetration and macro crack defects; The key parts are parts of the welding structure where defects have occurred and parts that may appear artificially; In the global finite element model of the defective welded structure, the displacement of the sub-model boundary is obtained as the boundary condition of the sub-model; In the process of calculating the current stress field intensity factor, the global finite element model of the welded structure with defects is used as the boundary condition of the sub-finite element model of the key part; A second calculation module is used to obtain a stress field intensity factor threshold value of a defective welded structure based on a fracture mechanics test and a critical defect length of a defective welded structure based on a damage mechanics test; The process of obtaining the critical defect length is as follows: Based on the damage mechanics test, a failure assessment diagram is drawn. The contour of the failure assessment diagram is determined by the material of the defective welded structure. The horizontal coordinate of the failure assessment diagram is Lr, and the vertical coordinate is Kr, and both are functions of the defect length; where Lr= / σ s , is the reference stress, for a certain material, σ s To determine the value, the calculation formula of the reference stress is: ,in, , Depends on the external load, is the ratio of crack length to plate thickness; ,in, is the normalized stress field intensity factor, is the material parameter, is the stress field intensity factor, , F is the shape factor, is the defect regularized to half of the minor axis of the ellipse, is the nominal stress; As the damage evolves, the reference stress and the stress field intensity factor increase simultaneously and eventually intersect with the contour line. The defect size at this time is the critical defect size. The remaining life prediction module is used to compare the current stress field intensity factor with the stress field intensity factor threshold value: If the former is less than the latter, the defect is safe; otherwise, based on the relationship between the operating mileage and the defect length, when the defect length reaches the critical defect length, the operating mileage is the remaining life of the defective welded structure under the set survival rate; The relationship between the operating mileage and the defect length is calculated as follows: in, is the half of the minor axis of the ellipse regularized by the defect, n is the number of groups of load cycles converted from the load spectrum of the defective welded structure in a single load history, C is the crack growth rate coefficient, m is the crack growth rate index, is the current stress field intensity factor under fatigue load.

7. The probabilistic remaining life prediction system for a defective welded structure according to claim 6, characterized in that: The probabilistic remaining life prediction system of the defective welded structure further includes: A model correction module is used to correct the relationship between operating mileage and defect length based on fatigue failure test data of full-size welded joints.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: Implement the steps in the probabilistic remaining life prediction method for a defective welded structure as described in any one of claims 1-5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps in the probabilistic remaining life prediction method for a defective welded structure as described in any one of claims 1 to 5 are implemented.

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