A method and device for optimizing welding structure parameters based on structural stress and a medium

Abstract

This application discloses a method, apparatus, and medium for optimizing welded structure parameters based on structural stress. It relates to the field of welding technology and addresses the problems of repeated fatigue strength checks and high computational costs associated with optimizing welded structures after optimization. This application pre-determines the equivalent structural stress allowable value corresponding to the target fatigue life based on the master S-N curve, transforming the fatigue life requirement into a stress constraint. After each iteration, the weld fatigue strength is evaluated, and the calculation results are compared with the preset constraints, outputting only the optimized results that meet the fatigue strength requirements. By moving the weld fatigue strength evaluation from after optimization to after each iteration, real-time evaluation is achieved, ensuring that the optimized parameters generated in each iteration are used to determine whether they meet the weld fatigue strength requirements. Furthermore, by using weld fatigue strength as a constraint during the iteration process, rather than using it separately for fatigue strength checks after iteration optimization, the optimization results are guaranteed to meet the requirements, eliminating repeated iterations.

Description

Technical Field

[0001] This application relates to the field of welding technology, and in particular to a method, apparatus and medium for optimizing welding structural parameters based on structural stress. Background Technology

[0002] Welded structures are widely used in fields such as rail transit equipment and construction machinery. Weld fatigue failure is a major form of structural failure, and engineering projects must ensure fatigue life while implementing lightweight design. Currently, finite element method (FEM) software is commonly used to optimize structural parameters, and the weld strength is then checked separately after optimization.

[0003] Currently, the typical workflow for parametric optimization of welded structures using finite element method (FEM) software is as follows: First, a finite element model including the base material is established (usually ignoring the weld or treating it as integral with the base material); then, optimization objectives (such as minimizing structural weight and maximizing stiffness) and design variables (such as plate thickness) are set; next, iterative calculations are performed using optimization algorithms; finally, after the optimization results converge, a refined weld model is rebuilt based on the final geometric parameters, and its fatigue strength is checked separately. In this process, the calculation and evaluation of structural stress is a crucial analytical method.

[0004] The structural stress method is an engineering analysis method specifically used for fatigue life assessment of welded structures. It effectively predicts the fatigue life of welds by integrating nodal forces and using master SN curves (fatigue curves). The calculation process typically involves calculating structural stresses after finite element analysis.

[0005] During the optimization process, no weld model is established and the weld strength is calculated. The weld is checked after optimization. This method has the following disadvantages: when the plate thickness of the welded joint changes iteratively during the optimization process, the fatigue strength of the weld cannot be calculated in real time; after optimization, the weld strength is checked. If it is not qualified, the optimization conditions need to be reset. It cannot be guaranteed that the reset will take effect after one reset. The calculation cost is high and the optimization cycle is greatly extended.

[0006] Therefore, providing a method for optimizing welding structure parameters to improve optimization accuracy and efficiency is a technical problem that urgently needs to be solved by those in the field. Summary of the Invention

[0007] The purpose of this application is to provide a method, device and medium for optimizing welded structure parameters based on structural stress, which solves the technical problems of traditional welded structure optimization processes, such as the inability to evaluate weld fatigue strength in real time, the need for repeated verification after optimization and high calculation costs.

[0008] To address the aforementioned technical problems, this application provides a method for optimizing welded structure parameters based on structural stress, comprising: Establish a finite element model of the welded structure including the weld joint; The equivalent structural stress allowable value corresponding to the target fatigue life is determined based on the main SN curve, and the equivalent structural stress allowable value is used as the fatigue strength constraint condition for welded structure optimization. Boundary conditions and preset load conditions are applied to the finite element model of the welded structure, and iterative optimization is performed to solve the problem. After each iteration of optimization, the equivalent structural stress at the weld toe position of the weld joint is calculated; Compare the current equivalent structural stress with the fatigue strength constraint conditions; When the equivalent structural stress satisfies the fatigue strength constraint, the optimized parameters of the current welded structure are output.

[0009] Optionally, in the above-mentioned method for optimizing welded structural parameters based on structural stress, calculating the equivalent structural stress at the weld toe position of the weld joint includes: Mark the unit node identifier at the weld toe, and extract the nodal forces and nodal moments in the global coordinate system; transform the nodal forces and nodal moments to the local coordinate system at the weld toe position through coordinate system transformation; Based on the element side length at the weld toe, the converted nodal forces and nodal moments are converted into line forces and line moments; Based on the plate thickness of the welded structure, the linear force and linear moment are integrated to obtain the membrane stress and bending stress. The structural stress is obtained by superimposing the membrane stress and the bending stress. The structural stress is converted into the equivalent structural stress by using a thickness correction factor and a load mode coefficient.

[0010] Optionally, in the above-mentioned method for optimizing welded structure parameters based on structural stress, before applying boundary conditions and preset load conditions to the finite element model of the welded structure and performing iterative optimization, the method further includes: The finite element model of the welded structure is parameterized, with the geometric parameters of the welded structure set as analysis factors and the finite element analysis results set as the response; Run a full factorial experimental design and perform correlation analysis between the analytical factors and the response; The design variables in the iterative optimization solution are determined based on the correlation analysis results.

[0011] Optionally, in the above-mentioned method for optimizing welded structural parameters based on structural stress, the analysis factors include: plate thickness, weld length, and weld toe width; the response includes: Von Mises stress, structural stress, and strain energy density.

[0012] Optionally, in the above-mentioned method for optimizing welded structure parameters based on structural stress, the optimization objective of the iterative optimization solution is to minimize the weight of the welded structure or maximize the stiffness of the welded structure. The optimization constraints for the iterative optimization solution also include: Von Mises stress constraints, deformation constraints, and strain energy density constraints.

[0013] Optionally, in the above method for optimizing welded structural parameters based on structural stress, the equivalent structural stress satisfies the fatigue strength constraint condition by being less than or equal to the allowable value of the equivalent structural stress.

[0014] Optionally, in the above-mentioned method for optimizing welded structure parameters based on structural stress, establishing a finite element model of the welded structure including the weld joint includes: Establish a geometric model of the welded structure including the weld joint; The geometric model is meshed to form a discretized finite element model of the welded structure; Material properties are specified for the base material and weld joint in the finite element model of the welded structure. The material properties include: elastic modulus, Poisson's ratio, density, yield strength and material constitutive relation.

[0015] To address the aforementioned technical problems, this application also provides a welding structure parameter optimization device based on structural stress, comprising: A module is created to build a finite element model of a welded structure that includes weld joints; The preset module is used to determine the equivalent structural stress allowable value corresponding to the target fatigue life based on the main SN curve, and to use the equivalent structural stress allowable value as the fatigue strength constraint condition for welded structure optimization. The optimization module is used to apply boundary conditions and preset load conditions to the finite element model of the welded structure and perform iterative optimization solutions. The analysis module is used to calculate the equivalent structural stress at the weld toe position of the weld joint after each iteration of optimization. The comparison module is used to compare the current equivalent structural stress with the fatigue strength constraint conditions; The output module is used to output the optimized parameters of the current welded structure when the equivalent structural stress meets the fatigue strength constraint condition.

[0016] To address the aforementioned technical problems, this application also provides a welding structure parameter optimization device based on structural stress, comprising: Memory, used to store computer programs; A processor is used to implement the steps of the above-described method for optimizing welded structure parameters based on structural stress when executing the computer program.

[0017] To address the aforementioned technical problems, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the aforementioned method for optimizing welded structural parameters based on structural stress.

[0018] The structural stress-based welding structure parameter optimization method provided in this application establishes a finite element model of the welded structure that includes the weld joint. The equivalent allowable structural stress value corresponding to the target fatigue life is pre-determined based on the master SN curve, transforming the fatigue life requirement into a quantifiable stress constraint. After each iteration, the weld fatigue strength is evaluated, and the calculation results are compared with the preset constraints. Only optimization results that meet the fatigue strength requirements are output. This application moves the weld fatigue strength evaluation from after optimization to after each iteration, achieving real-time evaluation. This ensures that the optimization parameters generated in each iteration are judged to meet the weld fatigue strength requirements, fundamentally improving the engineering practicality of the optimization results. Furthermore, by using weld fatigue strength as a constraint condition during the iteration process, rather than using it separately for fatigue strength verification after iteration optimization, it ensures that the optimization results meet the requirements, eliminates repeated iterations, and shortens the optimization cycle. It also eliminates the need to establish a separate detailed weld model for secondary analysis, reducing overall computational resource consumption.

[0019] In addition, this application also provides an apparatus and medium that correspond to the above-mentioned method for optimizing welding structure parameters based on structural stress, and have the same effect. Attached Figure Description

[0020] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A flowchart is provided for an embodiment of this application to show a method for optimizing welded structure parameters based on structural stress; Figure 2 A flowchart illustrating an embodiment of a method for optimizing welded structure parameters based on structural stress, provided in this application. Figure 3 A structural diagram of a welding structure parameter optimization device based on structural stress provided in this application embodiment; Figure 4 A structural diagram of another welding structure parameter optimization device based on structural stress provided in an embodiment of this application. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.

[0023] The core of this application is to provide a method, apparatus, and medium for optimizing welded structural parameters based on structural stress.

[0024] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] This application provides a method for optimizing welded structure parameters based on structural stress, such as... Figure 1 As shown, it includes: S11: Establish a finite element model of the welded structure including the weld joint; S12: Determine the equivalent structural stress allowable value corresponding to the target fatigue life based on the main SN curve, and use the equivalent structural stress allowable value as the fatigue strength constraint condition for welded structure optimization. S13: Apply boundary conditions and preset load conditions to the finite element model of the welded structure and perform iterative optimization solution; S14: Calculate the equivalent structural stress at the weld toe position of the weld joint after each iteration of optimization; S15: Compare the current equivalent structural stress with the fatigue strength constraint conditions; S16: When the equivalent structural stress meets the fatigue strength constraint, output the optimized parameters of the current welded structure.

[0026] Step S11, establishing a finite element model of the welded structure including the weld joint, refers to discretizing the welded structure to be optimized and explicitly including the weld joint region. Since fatigue strength calculations are subsequently required for the weld toe location, the weld structure cannot be omitted from the model.

[0027] Finite element model of welded structure: a numerical calculation model composed of nodes, elements, materials, and boundaries; weld joint refers to the welded connection area, including fatigue-critical locations such as weld toe and weld root. It can be a linear elastic model or an elastoplastic model, and this embodiment does not impose strict limitations.

[0028] Step S12 determines the equivalent structural stress allowable value corresponding to the target fatigue life based on the main SN curve, and uses it as a fatigue strength constraint. According to the structural stress method standard, the fatigue strength threshold value is first determined, and then used as the optimization constraint.

[0029] The allowable equivalent structural stress refers to the maximum allowable equivalent structural stress at the weld location when the target fatigue life is met; the fatigue strength constraint condition refers to the fatigue safety condition that must be met during the optimization process. It can be the allowable stress corresponding to a design life of 1 million cycles, or the allowable stress specified by industry standards; this embodiment does not impose strict limitations.

[0030] Step S13 applies boundary conditions and preset load cases to the finite element model and performs iterative optimization. The boundary conditions simulate the actual support and constraints of the structure, while the preset load cases reflect the actual working loads. Iterative optimization refers to automatically adjusting structural parameters and repeatedly calculating based on preset targets. Iterative optimization automatically adjusts parameters such as plate thickness and weld dimensions, providing a dynamically changing structural form for subsequent stress calculations.

[0031] Step S14 calculates the equivalent structural stress at the weld toe position of the weld joint after each iteration optimization. Since parameters such as plate thickness and weld size will change dynamically during the iteration process, the weld stress will also change synchronously. Therefore, it is necessary to calculate the fatigue-related stress at the key position of the weld in real time each time.

[0032] Step S15 compares the current equivalent structural stress with the fatigue strength constraints, comparing the stress calculated in this iteration with the allowable stress upper limit determined in step S12. This determines whether the current iterative optimization scheme meets fatigue safety requirements, providing a basis for deciding whether to continue the iteration. It should be noted that this comparison does not signify the end of the optimization process; it is merely a compliance check for a single iteration.

[0033] Step S16: When the equivalent structural stress meets the fatigue strength constraint, output the optimized parameters of the current welded structure. Meeting the constraint means that the equivalent structural stress is less than or equal to the allowable value. At this point, the output parameters simultaneously meet the optimization objective and fatigue safety requirements, and the final solution can be output without further verification.

[0034] Preferably, the finite element model is reconstructed using the optimized parameters, and independent verification analysis is performed. The optimization results are automatically compared with the verification results to verify the reliability of the optimization. The equivalent structural stress of each weld is checked one by one, and an optimization report is automatically generated, including parameter and stress analysis before and after optimization, to identify potential errors in the optimization process.

[0035] The welding structure parameter optimization method based on structural stress provided in this application establishes a finite element model of the welded structure that includes the weld joint. The equivalent allowable structural stress value corresponding to the target fatigue life is pre-determined based on the master SN curve, transforming the fatigue life requirement into a quantifiable stress constraint. After each iteration, the weld fatigue strength is evaluated, and the calculation results are compared with the preset constraints. Only optimization results that meet the fatigue strength requirements are output. This application moves the weld fatigue strength evaluation from after optimization to after each iteration, achieving real-time evaluation. This ensures that the optimization parameters generated in each iteration are judged to meet the weld fatigue strength requirements, fundamentally improving the engineering practicality of the optimization results. Furthermore, by using weld fatigue strength as a constraint condition during the iteration process, rather than using it separately for fatigue strength verification after iteration optimization, it ensures that the optimization results meet the requirements, eliminates repeated iterations, and shortens the optimization cycle. It also eliminates the need to establish a separate detailed weld model for secondary analysis, reducing overall computational resource consumption.

[0036] Furthermore, in one specific embodiment, calculating the equivalent structural stress at the weld toe position of the weld joint includes: Mark the element node identifiers at the weld toe and extract the nodal forces and moments in the global coordinate system; transform the nodal forces and moments to the local coordinate system at the weld toe location through coordinate system transformation. Based on the element side length at the weld toe, the converted nodal forces and nodal moments are converted into line forces and line moments; Based on the plate thickness of the welded structure, the linear force and linear moment are integrated to obtain the membrane stress and bending stress. The structural stress is obtained by superimposing the membrane stress and the bending stress. The structural stress is converted into equivalent structural stress by using a thickness correction factor and a load mode coefficient.

[0037] It should be noted that this step is the core stress calculation embodiment of this application. Its working process is as follows: First, mark the weld toe node ID (serial number) and extract the nodal forces and moments in the global coordinate system; then, transform them to the local coordinate system of the weld toe; subsequently, convert them into linear forces and moments according to the element side length; obtain the membrane stress and bending stress based on the plate thickness integral, and superimpose them to obtain the structural stress; finally, convert the structural stress into equivalent structural stress that can be directly used for fatigue assessment using the thickness correction factor and load mode coefficient.

[0038] The element side length refers to the side length of each element located on the weld toe line in the finite element mesh along the weld toe line direction.

[0039] Based on the beam / plate theory in mechanics of materials, linear forces generate uniformly distributed membrane stress along the thickness direction of the plate, while linear moments generate linearly distributed bending stress along the thickness direction. The membrane stress and bending stress can be calculated separately by integrating along the thickness direction.

[0040] Since this embodiment adopts the standard calculation path of structural stress method throughout, the calculation results are independent of mesh density, element type, and structural form, and its stability and versatility are significantly better than traditional nodal stress.

[0041] In practical implementation, the mesh can be refined only in stress concentration regions, ensuring the accuracy of stress calculation at the weld toe while avoiding the increased computational cost of global refinement. For example, a coarser mesh is first used for finite element analysis to preliminarily calculate the equivalent structural stress distribution. The gradient change of equivalent structural stress along the weld toe line is identified; a larger gradient indicates more severe stress concentration. The mesh is automatically refined in high stress gradient regions, and the calculation is re-performed. The changes in equivalent structural stress before and after refinement are compared, and refinement stops when the change is less than a preset threshold (e.g., 1%).

[0042] Furthermore, in a specific embodiment, a DOE parameter analysis step is defined before the iterative optimization solution. Boundary conditions and preset load conditions are applied to the finite element model of the welded structure, and iterative optimization solution is performed. Prior to this, the following steps are also included: The finite element model of the welded structure is parameterized by setting the geometric parameters of the welded structure as analysis factors and the finite element analysis results as the response. Run a full factorial experimental design and perform correlation analysis between the analysis factors and the response; The design variables in the iterative optimization solution are determined based on the results of correlation analysis.

[0043] Design of Experiments (DOE) is a systematic experimental method based on mathematical statistics. In this embodiment, the purpose of DOE parameter analysis is to analyze the influence of each geometric parameter on the structural response before formally carrying out optimization iterations, thereby scientifically selecting design variables.

[0044] The geometric parameters of the welded structure are set as analysis factors. Analysis factors are variables whose effects need to be examined in DOE experiments. By setting the geometric parameters as analysis factors and the finite element analysis results as the response, we can identify which parameters have a greater impact on the structural performance.

[0045] Simultaneously, the finite element analysis results are set as the response. The response refers to the output result that needs to be observed in the DOE test.

[0046] Performing correlation analysis using a full factorial experimental design involves traversing all factor combinations and calculating the degree of influence, trend of influence, and interactions of each factor on the response using mathematical statistics. While computationally intensive, full factorial designs can accurately assess the main effects of each factor and the interactions between factors. When the model size is small and computational costs are acceptable, full factorial designs are the optimal choice. For large-scale models, partial factorial designs or orthogonal array designs can be used to reduce computational costs.

[0047] The DOE analysis outputs a main effects plot and a Pareto plot. The main effects plot shows the trend of response changes when a single factor changes; the Pareto plot sorts the effects of each factor on the response from largest to smallest.

[0048] The beneficial effect of this embodiment is that, before formal optimization, DOE analysis reveals the influence of various geometric parameters on the structural fatigue strength. This allows for more accurate selection of design variables, avoiding the waste of computational resources on variables with minimal impact on the response. In other words, this embodiment improves the targeting and efficiency of optimization calculations.

[0049] Furthermore, in one specific embodiment, the analysis factors include: plate thickness, weld length, and weld toe width; the response includes: Von Mises stress, structural stress, and strain energy density.

[0050] The analysis factors include plate thickness, weld length, and weld toe width. These are the most easily adjustable geometric parameters in welded structures that have the most significant impact on weight and stress, and are also the most commonly used optimization variables in engineering design.

[0051] The response includes Von Mises stress, structural stress, and strain energy density, where: Von Mises stress is used to determine overall strength; structural stress is used to determine weld fatigue; and strain energy density is used to determine structural stiffness and deformation trend.

[0052] Analysis factors may also include weld leg size, weld angle, connecting plate width, and opening location; responses may also include maximum displacement, modal frequency, fatigue life, and stress amplitude to accommodate more complex structures.

[0053] This embodiment uses DOE analysis to achieve clear objectives, comprehensive indicators, and clear engineering significance, avoiding computational waste caused by invalid parameters and responses, and improving analysis efficiency and reliability.

[0054] Furthermore, in a specific embodiment, the optimization objective of the iterative optimization solution is to minimize the weight of the welded structure or maximize the stiffness of the welded structure. The optimization constraints for iterative optimization solutions also include: Von Mises stress constraints, deformation constraints, and strain energy density constraints.

[0055] The iterative optimization objective is to minimize weight or maximize stiffness, which is the most typical engineering objective for welded structures: minimizing weight achieves lightweighting, and maximizing stiffness ensures structural stability.

[0056] Additional constraints include Von Mises stress (paradigm equivalent stress), deformation constraints, and strain energy density constraints, which are used to limit the overall strength of the structure, the amount of structural deformation, and the level of structural energy absorption, respectively.

[0057] These constraints, together with fatigue strength constraints, ensure that the optimization process does not encounter problems such as insufficient strength, excessive deformation, weak stiffness, or fatigue cracking.

[0058] This embodiment achieves a balance between safety and performance optimization. The output structure is no longer optimal for a single indicator, but rather for overall performance, which is more in line with the requirements of actual engineering applications.

[0059] Furthermore, the optimization objectives can also be minimum volume, minimum cost, and optimal center of mass; additional constraints can also include buckling constraints, frequency constraints, stress ratio constraints, and fatigue life constraints, so that the scope of application can be further expanded.

[0060] Furthermore, in one specific embodiment, the equivalent structural stress satisfies the fatigue strength constraint condition as follows: the equivalent structural stress is less than or equal to the allowable value of the equivalent structural stress.

[0061] The equivalent structural stress satisfies the fatigue strength constraint and is defined as the equivalent structural stress being less than or equal to the allowable equivalent structural stress value. The allowable equivalent structural stress value is determined jointly by the master SN curve and the target fatigue life, representing the maximum stress limit at which the structure will not experience fatigue failure within its design life.

[0062] At this point, each iteration only requires a simple numerical comparison to determine whether the current structure meets the fatigue safety requirements.

[0063] This embodiment provides a clear stopping logic for optimization iteration, avoiding the uncertainty caused by manual or fuzzy judgments, and ensuring that the optimization results meet the requirements.

[0064] Furthermore, in one specific embodiment, establishing a finite element model of the welded structure including the weld joint includes: Establish a geometric model of the welded structure including the weld joint; The geometric model is meshed to form a discretized finite element model of the welded structure; Specify material properties for the base material and weld joint in the finite element model of the welded structure. Material properties include: elastic modulus, Poisson's ratio, density, yield strength, and material constitutive relation.

[0065] This embodiment first establishes a geometric model including the weld joint, with the aim of fully restoring the true shape of the structure without omitting the weld, a key fatigue part.

[0066] Mesh the geometric model to form a discretized finite element model, which is to transform the continuous structure into a combination of elements and nodes that can be computed by a computer.

[0067] Assign material properties to the base material and the weld joint separately. Since the elastic modulus, yield strength and fatigue performance of the base material and the weld are usually different, assigning values ​​separately can ensure the accuracy and reliability of mechanical calculations.

[0068] Material properties include elastic modulus, Poisson's ratio, density, yield strength, and material constitutive relations, covering all parameters required for static analysis, fatigue analysis, and optimization analysis.

[0069] Based on this, the finite element model constructed in this embodiment is geometrically accurate, mechanically reasonable, and computationally stable, providing a high-precision foundation for subsequent stress calculation, parameter analysis, and iterative optimization, and avoiding systematic errors introduced by model simplification.

[0070] Figure 2 A flowchart illustrating an embodiment of a welding structure parameter optimization method based on structural stress provided in this application is shown below. Figure 2 As shown, firstly, the problem and objective of the welded structure to be optimized (such as lightweighting) are clarified, a finite element model including the weld joint is established, and boundary conditions and preset load conditions are applied. During the modeling process, the material properties of the base material and the weld need to be defined separately to ensure the geometric and mechanical integrity of the model, laying the foundation for subsequent calculations.

[0071] Secondly, DOE parameter analysis and correlation analysis are performed: As shown on the left side of the attached figure, this embodiment introduces DOE experimental design technology. Geometric parameters such as plate thickness, weld length, and weld toe width are set as analysis factors, and mechanical indices such as structural stress, Von Mises stress, and strain energy density are set as responses. Through full factorial experimental design and correlation analysis, main effect plots and Pareto plots are output to quantify the influence of each factor on performance, thereby scientifically selecting parameters that have a significant impact on structural stress as design variables for subsequent iterations, and eliminating irrelevant parameters to improve optimization efficiency.

[0072] Next, the core process of structural stress calculation is executed: as shown on the right side of the attached diagram, before and after each iteration of optimization, the system automatically extracts the global nodal forces / moments at the weld toe location. Through a series of calculations including coordinate transformation, element side length transformation, and plate thickness integration, the equivalent structural stress is finally obtained. This calculation method, based on the structural stress method, is unaffected by mesh sensitivity, ensuring the accuracy of weld fatigue strength assessment.

[0073] Then, the system performs optimization by setting the three key elements and iterative optimization: combining the aforementioned analysis results and structural stress calculation data, the system sets optimization objectives (such as minimum weight) and constraints (including Von Mises stress constraints and deformation constraints), and specifically uses the allowable value of equivalent structural stress determined based on the master SN curve as the core fatigue strength constraint. Iterative optimization is then initiated, and the algorithm automatically adjusts the design parameters.

[0074] Finally, the iterative judgment and output are performed: After each iteration of optimization, the equivalent structural stress at the weld toe position is calculated in real time and compared with the constraint conditions. When the equivalent structural stress meets the fatigue strength requirement (i.e., less than or equal to the allowable value) and the optimization objective is achieved, the program stops iterating and outputs the optimal parameters of the current welded structure.

[0075] In the above embodiments, the method for optimizing welded structure parameters based on structural stress has been described in detail. This application also provides embodiments of a device for optimizing welded structure parameters based on structural stress. It should be noted that this application describes the embodiments of the device from two perspectives: one is based on functional modules, and the other is based on hardware.

[0076] From the perspective of functional modules Figure 3 A structural diagram of a welding structure parameter optimization device based on structural stress provided in this application embodiment is shown below. Figure 3 As shown, a welding structure parameter optimization device based on structural stress includes: Module 11 is established to create a finite element model of a welded structure containing weld joints; The preset module 12 is used to determine the equivalent structural stress allowable value corresponding to the target fatigue life based on the main SN curve, and to use the equivalent structural stress allowable value as the fatigue strength constraint condition for welded structure optimization. Optimization module 13 is used to apply boundary conditions and preset load conditions to the finite element model of the welded structure and perform iterative optimization solutions. Analysis module 14 is used to calculate the equivalent structural stress at the weld toe position of the weld joint after each iteration of optimization. The comparison module 15 is used to compare the current equivalent structural stress with the fatigue strength constraint conditions; Output module 16 is used to output the optimized parameters of the current welded structure when the equivalent structural stress meets the fatigue strength constraint condition.

[0077] Since the embodiments of the apparatus and the embodiments of the method correspond to each other, please refer to the description of the embodiments of the method for the embodiments of the apparatus, which will not be repeated here.

[0078] Figure 4A structural diagram of another welding structure parameter optimization device based on structural stress provided in this application embodiment is shown below. Figure 4 As shown, the welding structure parameter optimization device based on structural stress includes: a memory 20 for storing computer programs; The processor 21 is used to implement the steps of the method for obtaining user operation habit information as described in the above embodiment (method for optimizing welded structure parameters based on structural stress) when executing a computer program.

[0079] The welding structure parameter optimization device based on structural stress provided in this embodiment may include, but is not limited to, mobile terminals, personal computers, workstations, etc.

[0080] The processor 21 may include one or more processing cores, such as a quad-core processor or an octa-core processor. The processor 21 may be implemented using at least one of the following hardware forms: Digital Signal Processor (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor, also known as the Central Processing Unit (CPU), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 21 may integrate a Graphics Processing Unit (GPU), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor 21 may also include an Artificial Intelligence (AI) processor, which handles computational operations related to machine learning.

[0081] The memory 20 may include one or more computer-readable storage media, which may be non-transitory. The memory 20 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In this embodiment, the memory 20 is used to store at least the following computer program 201, which, after being loaded and executed by the processor 21, is capable of implementing the relevant steps of the structural stress-based welded structure parameter optimization method disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 20 may also include an operating system 202 and data 203, and the storage method may be temporary or permanent storage. The operating system 202 may include Windows, Unix, Linux, etc. The data 203 may include, but is not limited to, data involved in implementing the structural stress-based welded structure parameter optimization method.

[0082] In some embodiments, the welding structure parameter optimization device based on structural stress may further include a display screen 22, an input / output interface 23, a communication interface 24, a power supply 25, and a communication bus 26.

[0083] Those skilled in the art will understand that Figure 4 The structure shown does not constitute a limitation on the apparatus for optimizing welded structural parameters based on structural stress and may include more or fewer components than shown.

[0084] The welding structure parameter optimization device based on structural stress provided in this application includes a memory and a processor. When the processor executes the program stored in the memory, it can implement the following method: welding structure parameter optimization method based on structural stress.

[0085] Finally, this application also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps described in the above embodiment of the method for optimizing welded structure parameters based on structural stress.

[0086] It is understood that if the methods in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and executes all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0087] The computer-readable storage medium provided in this embodiment stores a computer program. When the processor executes the program, it can implement the following method: a method for optimizing welded structure parameters based on structural stress.

[0088] The above provides a detailed description of the method, apparatus, and medium for optimizing welded structural parameters based on structural stress provided in this application. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of this application.

[0089] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for optimizing a welding structure parameter based on structural stress, characterized in that, include: Establish a finite element model of the welded structure including the weld joint; The equivalent structural stress allowable value corresponding to the target fatigue life is determined based on the main SN curve, and the equivalent structural stress allowable value is used as the fatigue strength constraint condition for welded structure optimization. Boundary conditions and preset load conditions are applied to the finite element model of the welded structure, and iterative optimization is performed to solve the problem. After each iteration of optimization, the equivalent structural stress at the weld toe position of the weld joint is calculated; Compare the current equivalent structural stress with the fatigue strength constraint conditions; When the equivalent structural stress satisfies the fatigue strength constraint, the optimized parameters of the current welded structure are output.

2. The structural-stress-based weld-structure parameter optimization method according to claim 1, characterized by, Calculating the equivalent structural stress at the weld toe position of the weld joint includes: Mark the unit node identifier at the weld toe, and extract the nodal forces and nodal moments in the global coordinate system; transform the nodal forces and nodal moments to the local coordinate system at the weld toe position through coordinate system transformation; Based on the element side length at the weld toe, the converted nodal forces and nodal moments are converted into line forces and line moments; Based on the plate thickness of the welded structure, the linear force and linear moment are integrated to obtain the membrane stress and bending stress. The structural stress is obtained by superimposing the membrane stress and the bending stress. The structural stress is converted into the equivalent structural stress by using a thickness correction factor and a load mode coefficient.

3. The structural-stress-based weld-structure parameter optimization method according to claim 1, characterized by, Boundary conditions and preset load conditions are applied to the finite element model of the welded structure, and iterative optimization is performed to solve the problem. Prior to this, the following steps are also included: The finite element model of the welded structure is parameterized, with the geometric parameters of the welded structure set as analysis factors and the finite element analysis results set as the response; Run a full factorial experimental design and perform correlation analysis between the analytical factors and the response; The design variables in the iterative optimization solution are determined based on the correlation analysis results.

4. The structural-stress-based weld-structure parameter optimization method according to claim 3, characterized by, The analytical factors include: plate thickness, weld length, and weld toe width; the responses include: Von Mises stress, structural stress, and strain energy density.

5. The structural-stress-based weld-structure parameter optimization method according to claim 1, characterized by, The optimization objective of the iterative optimization solution is to minimize the weight of the welded structure or maximize the stiffness of the welded structure. The optimization constraints for the iterative optimization solution also include: Von Mises stress constraints, deformation constraints, and strain energy density constraints.

6. The structural-stress-based weld-structure parameter optimization method according to claim 1, characterized by, The equivalent structural stress satisfies the fatigue strength constraint condition as follows: the equivalent structural stress is less than or equal to the allowable value of the equivalent structural stress.

7. The structural-stress-based weld-structure parameter optimization method according to claim 1, characterized by, Establishing a finite element model of a welded structure including weld joints includes: Establish a geometric model of the welded structure including the weld joint; The geometric model is meshed to form a discretized finite element model of the welded structure; Material properties are specified for the base material and weld joint in the finite element model of the welded structure. The material properties include: elastic modulus, Poisson's ratio, density, yield strength and material constitutive relation.

8. A structural stress-based welding structure parameter optimization apparatus characterized by comprising: include: A module is created to build a finite element model of a welded structure that includes weld joints; The preset module is used to determine the equivalent structural stress allowable value corresponding to the target fatigue life based on the main SN curve, and to use the equivalent structural stress allowable value as the fatigue strength constraint condition for welded structure optimization. The optimization module is used to apply boundary conditions and preset load conditions to the finite element model of the welded structure and perform iterative optimization solutions. The analysis module is used to calculate the equivalent structural stress at the weld toe position of the weld joint after each iteration of optimization. The comparison module is used to compare the current equivalent structural stress with the fatigue strength constraint conditions; The output module is used to output the optimized parameters of the current welded structure when the equivalent structural stress meets the fatigue strength constraint condition.

9. A structural stress-based welding structure parameter optimization apparatus characterized by comprising: include: Memory, used to store computer programs; A processor, configured to implement the steps of the method for optimizing welded structure parameters based on structural stress as described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method for optimizing welded structural parameters based on structural stress as described in any one of claims 1 to 7.

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