Method and device for calculating fatigue safety coefficient of vehicle electric drive system and electronic equipment

Abstract

The embodiment of the invention provides a method and device for calculating the fatigue safety coefficient of a vehicle electric drive system and electronic equipment. The method comprises the steps that finite element modeling and assembling are conducted on a speed reducer shell assembly of a vehicle, material attributes are assigned to parts of the vehicle, and the parts comprise a speed reducer shell, a suspension support and bolts; a bolt pre-tightening working condition load and M suspension working condition loads are applied to the suspension point of the speed reducer shell of the vehicle, M + 1 load steps are generated respectively, and M is a positive integer; generating a load file according to the M + 1 load steps, solving a stress result of the speed reducer shell of the vehicle under each working condition according to the load file, and storing the stress result as an. Odb file; and calculating the fatigue safety coefficient of the electric drive system of the vehicle according to the. Odb file. Therefore, the calculation efficiency and accuracy of the fatigue safety coefficient of the vehicle electric drive system are remarkably improved, manual operation errors are reduced, and powerful technical support is provided for reliability and durability evaluation of the vehicle electric drive system.

Description

Technical Field

[0001] This application relates to the field of electric drive system simulation technology, and in particular to a method, device and electronic equipment for calculating the fatigue safety factor of a vehicle electric drive system. Background Technology

[0002] The fatigue safety factor is a key indicator for measuring a component's resistance to fatigue failure under cyclic loading, and it directly reflects the safety redundancy of the design. In electric drive systems, components such as motors, reducers, and housings are subjected to complex dynamic loads during operation, making them susceptible to fatigue cracks and failure due to repeated stress changes. Calculating this factor can assess component durability, predict lifespan, and provide a basis for design optimization. Furthermore, setting this factor appropriately can balance reliability and economy, avoiding increased costs and weight due to excessive redundancy, and ensuring the efficient and reliable operation of the electric drive system.

[0003] However, traditional methods for calculating fatigue safety factors require manually applying various working loads, calculating stress one by one, and then using software to analyze the fatigue safety factor. This process is cumbersome, repetitive, inefficient, and prone to errors. Summary of the Invention

[0004] This application aims to at least partially address one of the technical problems in the related art.

[0005] Therefore, the first objective of this application is to propose a method for calculating the fatigue safety factor of a vehicle electric drive system, which significantly improves calculation efficiency and accuracy, reduces the human error rate, and provides accurate data support and technical assurance for the reliability and durability assessment of vehicle electric drive systems.

[0006] The second objective of this application is to provide a device for calculating the fatigue safety factor of a vehicle electric drive system.

[0007] The third objective of this application is to propose an electronic device.

[0008] The fourth objective of this application is to provide a computer-readable storage medium.

[0009] The fifth objective of this application is to provide a computer program product.

[0010] To achieve the above objectives, the first aspect of this application proposes a method for calculating the fatigue safety factor of a vehicle electric drive system, comprising: performing finite element modeling and assembly of the vehicle's reducer housing assembly, and assigning material properties to the vehicle's parts, wherein the parts include the reducer housing, suspension brackets, and bolts; applying bolt preload and M suspension loads at the vehicle's reducer housing suspension points, and generating M+1 load steps, where M is a positive integer; generating a load file based on the M+1 load steps, and solving for the stress results of the reducer housing under each operating condition based on the load file, and saving the results as a .odb file (a file with the .odb extension, i.e., an output database file); and calculating the fatigue safety factor of the vehicle's electric drive system based on the .odb file.

[0011] The fatigue safety factor calculation method for vehicle electric drive systems according to embodiments of this application significantly improves calculation efficiency and accuracy, and reduces the human error rate. By automatically matching material library files and preset load steps, the flexibility and adaptability of the analysis are further improved, effectively shortening the R&D cycle and reducing development costs.

[0012] In addition, the method for calculating the fatigue safety factor of a vehicle electric drive system according to the above embodiments of this application may also have the following additional technical features: According to one embodiment of this application, calculating the fatigue safety factor of a vehicle's electric drive system based on a .odb file includes: selecting a .odb file in the front-end window; obtaining the corresponding .inp file (a file with the .inp extension, i.e., an input file) from the .odb file, parsing the .inp file, and matching it with a first preset keyword to obtain the correspondence between parts and materials; matching it with a second preset keyword and presetting the upper and lower amplitude stresses for each fatigue condition based on the matching results; setting multiple parameter types, including multiple types of solution type, input result file type, influence parameter, and storage file type; inputting a custom number of iterations through the front-end window, where the program defaults to N iterations, where N is a positive integer; and submitting the result to preset fatigue analysis software after setting the number of iterations to continuously calculate the fatigue safety factor of the electric drive system under multiple fatigue conditions.

[0013] According to one embodiment of this application, selecting a .odb file in the front-end window includes: selecting and / or entering the file path and name of the .odb file in the front-end window.

[0014] According to one embodiment of this application, matching is performed in the .inp file using a first preset keyword to obtain the correspondence between parts and materials. This includes: automatically locating the content of the definition section about parts and materials in the .inp file using the first preset keyword and reading the correspondence between parts and materials; and automatically matching material files in the material library based on the configuration relationship of material names.

[0015] According to one embodiment of this application, after matching in the .inp file by the second preset keyword, the process includes: identifying whether a pre-tightening condition exists by the second preset keyword; if it exists, the second load step is defaulted to be the effective load step for calculating the fatigue safety factor of the electric drive system; if it does not exist, the first load step is defaulted to be the effective load step for calculating the fatigue safety factor of the electric drive system.

[0016] According to one embodiment of this application, the default number of cycles is 1,000,000, and the preset fatigue analysis software is FEMFAT (Finite Element Method Fatigue Analysis Tool) software.

[0017] To achieve the above objectives, a second aspect of this application proposes a fatigue safety factor calculation device for a vehicle electric drive system, comprising: a finite element modeling and assembly module for performing finite element modeling and assembly of the vehicle's reducer housing assembly, and assigning material properties to the vehicle's parts, wherein the parts include the reducer housing, suspension brackets, and bolts; a load step generation module for applying bolt preload and M suspension loads at the vehicle's reducer housing suspension points, and generating M+1 load steps, where M is a positive integer; a processing module for generating an .inp file based on the M+1 load steps, solving for the stress results of the reducer housing under each operating condition, and saving the results as an .odb file; and a calculation module for calculating the fatigue safety factor of the vehicle's electric drive system based on the .odb file.

[0018] The fatigue safety factor calculation device for vehicle electric drive systems according to embodiments of this application significantly improves calculation efficiency and accuracy, and reduces the human error rate. By automatically matching material library files and preset load steps, it further enhances the flexibility and adaptability of the analysis, effectively shortening the R&D cycle and reducing development costs.

[0019] To achieve the above objectives, a third aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the aforementioned method for calculating the fatigue safety factor of a vehicle electric drive system.

[0020] The electronic device according to the embodiments of this application can implement the above-mentioned method for calculating the fatigue safety factor of a vehicle electric drive system when the processor executes a computer program. Based on the above-mentioned method for calculating the fatigue safety factor of a vehicle electric drive system, the calculation efficiency and accuracy are significantly improved, the human operation error rate is reduced, the flexibility and adaptability of the analysis are improved, the research and development cycle is effectively shortened, and the development cost is reduced.

[0021] To achieve the above objectives, a fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the aforementioned method for calculating the fatigue safety factor of a vehicle electric drive system.

[0022] According to the embodiments of this application, a computer-readable storage medium storing a computer program thereon implements the above-described method for calculating the fatigue safety factor of a vehicle electric drive system when executed by a processor. Based on the above-described method for calculating the fatigue safety factor of a vehicle electric drive system, the calculation efficiency and accuracy are significantly improved, the human error rate is reduced, the flexibility and adaptability of the analysis are improved, the research and development cycle is effectively shortened, and the development cost is reduced.

[0023] To achieve the above objectives, a fifth aspect of this application provides a computer program product, including a computer program that, when executed by a processor, implements the aforementioned method for calculating the fatigue safety factor of a vehicle electric drive system.

[0024] According to the computer program product of the present application embodiment, when the computer program is executed, it implements the above-mentioned method for calculating the fatigue safety factor of the vehicle electric drive system. Based on the above-mentioned method for calculating the fatigue safety factor of the vehicle electric drive system, the calculation efficiency and accuracy are significantly improved, the human operation error rate is reduced, the flexibility and adaptability of the analysis are improved, the research and development cycle is effectively shortened, and the development cost is reduced. Attached Figure Description

[0025] Figure 1 This is a flowchart of a method for calculating the fatigue safety factor of a vehicle electric drive system according to some embodiments of this application; Figure 2 This is a block diagram of a fatigue safety factor calculation device for a vehicle electric drive system according to some embodiments of this application; Figure 3 This is a block diagram of an electronic device according to some embodiments of this application. Detailed Implementation

[0026] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0027] Traditionally, FEMFAT software is used to assist in solving fatigue safety factors. FEMFAT is a professional fatigue analysis software primarily used to predict the fatigue life of mechanical structures under cyclic loading. By analyzing finite element results and combining material properties and load spectra, FEMFAT can accurately assess the fatigue performance of structures, providing crucial data support for engineering design. The software boasts rich features, including multi-dimensional fatigue analysis, material database management, professional fatigue calculations, and powerful post-processing capabilities, and can seamlessly integrate with mainstream finite element software. Utilizing these functions, FEMFAT can effectively identify fatigue risk areas, helping engineers optimize design solutions. It is widely used in the automotive, aerospace, and mechanical manufacturing industries, providing strong support for improving product reliability and design efficiency. This passage is fluent, logically clear, and effectively introduces the FEMFAT software and its applications.

[0028] The traditional process for solving fatigue safety factors using FEMFAT software is as follows: 1. Importing stress result files: This process may take 5-7 minutes, depending on the file size. Importing is prone to errors and inefficient due to complex file formats or large data volumes.

[0029] 2. Manual Grouping: The assembly structure is manually grouped according to the material properties of the parts. At least three groups are calculated at a time, and each group requires defining the component's mesh elements and nodes. Manual operation is time-consuming and error-prone; the rationality of the grouping relies on experience, and accuracy is difficult to guarantee.

[0030] 3. Manually setting fatigue calculation parameters: Manually setting peak-to-peak and peak-to-valley values ​​takes 10-15 minutes to read stress results. Manual parameter setting is inefficient, takes a long time when dealing with large files, and is prone to errors.

[0031] 4. Manually import material files: Each calculation requires importing at least two material files. Manual operation is prone to errors, and managing a large number of files is difficult, which affects efficiency.

[0032] 5. Manual material matching: Materials need to be manually matched for each group, which is tedious and prone to errors, especially when there are multiple groups and multiple materials, making it difficult to guarantee the accuracy of matching.

[0033] 6. Influencing parameter settings: Manually setting influencing parameters is prone to errors. Unreasonable parameters will affect the calculation accuracy. It requires experience-based judgment, is highly subjective, and affects the reliability of the results.

[0034] 7. Solver terms and parameter settings: Manually defining solver terms and parameters is prone to errors and inefficient. When there are many parameters, they are easy to be omitted or set improperly, which affects the calculation efficiency and the accuracy of the results.

[0035] 8. Input Results and File Definitions: Manually entering the file names and types of results is prone to errors, and managing multiple files can be chaotic, affecting subsequent result processing and analysis.

[0036] 9. Start solving.

[0037] The above operations are mostly standardized but tedious and repetitive, and the process is discontinuous. When the stress result file is large, the waiting time in the solution definition stage can be as long as 20 minutes before the calculation can begin, resulting in low overall efficiency.

[0038] The following describes in detail, with reference to the accompanying drawings, the method, apparatus, and electronic equipment for calculating the fatigue safety factor of a vehicle electric drive system according to embodiments of this application.

[0039] The fatigue safety factor calculation method for the vehicle electric drive system of this application can be implemented using finite element analysis software such as ABAQUS, ANSYS, and COMSOL Multiphysics. The following uses ABAQUS as an example to introduce the fatigue safety factor calculation method, device, and electronic equipment of the vehicle electric drive system of this application.

[0040] ABAQUS is a powerful finite element analysis software renowned for its superior nonlinear analysis capabilities and high-precision calculation results. It can handle complex material models and large deformation problems, making it suitable for various fields such as metal forming, automotive crash analysis, composite material analysis, biomechanics, and civil engineering. ABAQUS offers a rich library of elements and material models, supports multiple solvers, including implicit and explicit solvers, and can handle static, dynamic, linear, and nonlinear problems. It also supports multiphysics coupling analysis, such as thermo-structural coupling and fluid-structure interaction. ABAQUS has a user-friendly interface and provides powerful pre- and post-processing functions, facilitating model building, load application, and result visualization. It is widely used in industries such as automotive, aerospace, mechanical manufacturing, and electronics, and has unique advantages, especially in handling complex nonlinear problems, making it an important tool for engineering analysis and scientific research.

[0041] Figure 1 This is a flowchart illustrating a method for calculating the fatigue safety factor of a vehicle electric drive system according to some embodiments of this application. (Refer to...) Figure 1 The calculation method for the fatigue safety factor of a vehicle's electric drive system may include: S101 involves performing finite element modeling and assembly of the vehicle's reducer housing assembly, and assigning material properties to the vehicle's parts, including the reducer housing, suspension bracket, and bolts.

[0042] The reducer housing assembly is a key component of the vehicle's drive system, comprising the reducer housing, suspension brackets, bolts, and other parts. Its main function is to provide mechanical support for the reducer, protect the internal gears and other transmission components, and connect to the vehicle's suspension system via the suspension brackets to ensure smooth power transmission and reliable system operation.

[0043] Finite element modeling is a numerical modeling technique based on the finite element analysis method. It discretizes complex continuous structures into a finite number of elements and nodes. By applying boundary conditions and loads to these elements and nodes, numerical calculation methods are used to solve for the mechanical responses of the structure under specific working conditions, such as stress, strain, and displacement. This enables the prediction and analysis of structural performance and provides a scientific basis for engineering design.

[0044] Material properties refer to the inherent characteristics of materials in terms of physics, chemistry, and mechanics, including but not limited to elastic modulus (the ratio of stress to strain in the elastic deformation stage of a material, measured in Pa) and Poisson's ratio (the ratio of the absolute values ​​of transverse strain to axial strain when a material is subjected to axial force). These are important parameters for describing material behavior.

[0045] Specifically, firstly, the 3D geometric model of the vehicle reducer housing assembly is imported into the finite element preprocessing software and cleaned and repaired to ensure the model's integrity and accuracy. Next, the geometric model is meshed according to the analysis requirements to generate a finite element model. Then, the connection relationships between parts are defined, such as bolted connections and welding, to complete the assembly. For each part, its corresponding material parameters, such as elastic modulus, Poisson's ratio, and density, are input. Finally, the connection relationships between parts, such as bolted connections and welding, are defined, and corresponding constraints and load conditions are applied according to the actual working conditions to complete the finite element modeling and assembly of the vehicle reducer housing assembly, assigning corresponding material properties to each part. For example, if the reducer housing is made of aluminum, the elastic modulus can be defined as 74000 MPa and the Poisson's ratio as 0.3 in the finite element preprocessing software; if bolts and suspension brackets are made of steel, the elastic modulus can be defined as 2.1e5 MPa and the Poisson's ratio as 0.3 in the finite element preprocessing software.

[0046] S102, apply bolt preload and M suspension loads at the vehicle's reducer housing mounting point, and generate M+1 load steps respectively, where M is a positive integer.

[0047] Among them, the suspension point is the key connection position connecting the vehicle body and the wheel in the vehicle suspension system. It usually refers to the specific part where the suspension system is installed or fixed. It is an important node that transmits various dynamic loads (such as vibration and impact) between the vehicle body and the wheel, and plays a supporting and buffering role during the vehicle's operation.

[0048] Bolt preload refers to the load applied in advance in a bolted connection to generate and maintain a certain preload on the connection surface. In vehicle engineering, to ensure the reliability and sealing of the connection, it is usually necessary to apply a specific preload during bolt installation. This prevents the connected components from loosening due to vibration or other dynamic loads during vehicle operation, and also helps to evenly distribute the stress on the connection surface, thereby improving the fatigue life of the connection.

[0049] Suspension load refers to the various loads borne by the suspension system of a vehicle during driving, including the vertical load during normal driving and the lateral, longitudinal and vertical dynamic loads caused by uneven road surfaces, turning, acceleration or braking.

[0050] A load step is a basic unit used in finite element analysis to describe the response of a structure under different loading conditions. The loading process of complex structures is usually decomposed into multiple load steps, each applying specific loads and constraints to accurately track structural deformation, stress distribution, and other responses.

[0051] Specifically, firstly, the preload is determined based on the bolt specifications and design requirements, and a bolt preload load is applied accordingly. Then, in the finite element model, the contact surface between the bolt and the connected parts or the threaded portion of the bolt is selected, and the corresponding bolt preload load is applied. Next, the M suspension loads to be applied are determined based on the vehicle's design and usage requirements. For example, the number of suspension loads can be 28, typically including various typical operating conditions that the vehicle may encounter during operation, such as vertical loads, lateral loads, and longitudinal loads. The magnitude and direction of each load should be calculated and set according to the actual situation. At the suspension points in the finite element model, M (e.g., 28) suspension loads are applied sequentially. For each load, its location, direction, and magnitude should be clearly defined and set accordingly in the model. Loads can be applied using concentrated force, distributed force, or pressure. Then, in the finite element analysis software, create M+1 (e.g., 29) load steps. The first load step is used to apply the bolt preload condition load, and the subsequent M (e.g., 28) load steps are used to apply M (e.g., 28) suspension condition loads respectively.

[0052] S103 generates a load file based on M+1 load steps, and solves the stress results of the reducer housing under various working conditions based on the load file, and saves it as a .odb file.

[0053] The load file refers to a file containing all necessary information about the model, including its geometry, material properties, boundary conditions, and loads. Stress results, obtained in finite element analysis by solving for the model's response under load, show the stress distribution at various points within the model. Stress results are crucial indicators for evaluating structural strength and safety, helping engineers understand the structural stress state under different conditions and providing a basis for design optimization and problem diagnosis. The .odb file is an output database file format used in the finite element analysis software ABAQUS to store analysis results data, including stress, strain, and displacement. It is a binary file format capable of efficiently storing large amounts of result data and supporting post-processing queries, visualization, and further analysis.

[0054] Specifically, using the preprocessing function of the finite element analysis software, the defined M+1 (e.g., 29) load steps and related model information are exported as a load file. Then, the solver of the finite element analysis software calculates the load file to determine the stress distribution of the reducer housing under various operating conditions. After the solution is completed, the obtained stress results are saved in .odb file format for detailed analysis and visualization using the post-processing function of the finite element analysis software.

[0055] S104, calculate the fatigue safety factor of the vehicle's electric drive system based on the .odb file.

[0056] The fatigue safety factor of the vehicle's electric drive system is calculated based on the stress results obtained from the finite element analysis software, i.e., the saved .odb file.

[0057] This application first performs finite element modeling and assembly of the reducer housing assembly, assigning material properties. Then, it applies bolt preload and multiple suspension loads to generate corresponding load steps. Next, it generates a load file and solves for stress, saving the results as a .odb file. Finally, it calculates the fatigue safety factor of the electric drive system based on the stress results in the .odb file. This method efficiently and accurately calculates the fatigue safety factor of the electric drive system, significantly improving computational efficiency and accuracy, greatly shortening the development cycle and reducing labor costs, and providing strong support for the reliability and durability of vehicle design.

[0058] In some embodiments of this application, calculating the fatigue safety factor of the vehicle's electric drive system based on the .odb file includes: selecting the .odb file in the front-end window; obtaining the corresponding .inp file based on the .odb file, parsing the .inp file, and matching it with a first preset keyword to obtain the correspondence between parts and materials; matching it with a second preset keyword and presetting the upper and lower amplitude stresses for each fatigue condition based on the matching results; setting multiple parameter types, including multiple types of solution type, input result file type, influence parameter, and storage file type; inputting a custom number of iterations through the front-end window, where the program defaults to N iterations, where N is a positive integer; and submitting the preset fatigue analysis software after setting the number of iterations to continuously calculate the fatigue safety factor of the electric drive system under multiple fatigue conditions.

[0059] The .inp file is a commonly used input file format in finite element analysis software, used to define information such as the model's geometry, materials, boundary conditions, and loads. It contains all the descriptive information of the model and is fundamental to finite element analysis. Upper and lower amplitude stresses refer to the maximum stress (peak-to-peak stress) and minimum stress (peak-to-valley stress) experienced by a material or structure in each load cycle during fatigue analysis. They define the stress range of a material under cyclic loading and are key parameters for evaluating fatigue life.

[0060] Specifically, after selecting the .odb file in the front-end window, the program will obtain the corresponding .inp file based on that file and parse it. It will then match the .inp file using a first preset keyword to obtain the correspondence between parts and materials, and automatically match material files from the material library based on the material name. Simultaneously, it will use a second preset keyword to identify whether a pre-tightening condition exists, and preset the upper and lower amplitude stresses for each fatigue condition based on the matching results and preset rules.

[0061] Taking the preload condition as an example, the program matches the second and third load steps as the upper and lower amplitude stress load steps of the first fatigue condition; it matches the fourth and fifth load steps as the upper and lower amplitude stress load steps of the second fatigue condition, and so on, until all load steps are matched.

[0062] Users can then set multiple parameter types, including solution type, input result file type, influencing parameters, and storage file type. For example, the solution type can be either static or fatigue solution, and the input result file type can be specified as both binary and text files, or influencing parameters (such as stress concentration factor and temperature load) can be considered. Specific settings depend on individual requirements and are not listed here. These parameter types can be user-defined or pre-defined by the program; there are no specific restrictions.

[0063] Finally, users can enter a custom number of loops in the front-end window. The program's default number of loops is N (e.g., 1,000,000). After setting, the program automatically submits the results to a preset fatigue analysis software (such as FEMFAT software) for calculation, continuously solving for the fatigue safety factor of the electric drive system under multiple fatigue conditions.

[0064] This application automatically parses files and matches key information through a program, reducing manual operations and improving efficiency. Users can customize parameters to meet different analysis needs, enhancing flexibility. Combined with professional software, it ensures calculation accuracy, supports continuous calculation of multiple operating conditions, further improves analysis efficiency, and effectively supports the reliability design and evaluation of vehicle electric drive systems.

[0065] In some embodiments of this application, selecting a .odb file in the front-end window includes: selecting and / or entering the file path and name of the .odb file in the front-end window.

[0066] Specifically, open the front-end window of the finite element analysis software (such as ABAQUS), select and / or enter the file path and name of the .odb file in the front-end window, and search for and select the .odb file.

[0067] As a specific embodiment of this example, taking ABAQUS as an example, enter the file selection interface, and select "Open" or "Import Result File" by clicking the "File" menu or the corresponding "Import" button. In the pop-up file browser window, navigate to the folder containing the .odb file, select the target .odb file and confirm the selection, or manually enter the full path and filename of the .odb file in the specified input box. After completing the input of the file path and name, click the "OK" or "Apply" button to register the path and name information of the selected .odb file into the software for subsequent reading and processing.

[0068] This application only defines the path and name of the stress result file, without involving the parsing or reading of the file content. Therefore, users can continue with subsequent operations without waiting. This process improves operational efficiency and simplifies the user's file selection process.

[0069] In some embodiments of this application, matching is performed in the .inp file using a first preset keyword to obtain the correspondence between parts and materials. This includes: automatically locating the content of the definition section about parts and materials in the .inp file using the first preset keyword and reading the correspondence between parts and materials; and automatically matching material files in the material library based on the configuration relationship of material names.

[0070] The first preset keyword is a keyword used in finite element analysis software to define material properties, and is used to identify and define the physical and mechanical properties of the material used in the model. For example, the first preset keyword is "MATERIAL".

[0071] Specifically, the first preset keyword (such as "MATERIAL") is followed by the abbreviated material name of the engineer. For example, if the material corresponding to a certain part is "M_AL", the program will match the obtained abbreviated material "M_AL" to the material file in the material library used for solving the safety factor, thus completing the automatic matching of parts and materials.

[0072] Specifically, first, the program automatically scans the .inp file, searching for a first preset keyword (such as "MATERIAL") to locate the material definition section. Next, it reads the content following the keyword, extracting the material name and related properties (such as elastic modulus, Poisson's ratio, etc.), and reads the correspondence between parts and materials. Finally, based on the configuration of material names, it automatically matches the corresponding material file in the material library, ensuring that correct material data is used during analysis.

[0073] This application significantly improves the efficiency and accuracy of material matching by automatically obtaining the correspondence between parts and materials by matching a first preset keyword (such as "MATERIAL") in the .inp file, reducing the error rate of manual operation, ensuring the correctness of material data in finite element analysis, and thus improving the reliability and automation level of the entire analysis process.

[0074] In some embodiments of this application, after matching in the .inp file using the second preset keyword, the process includes: identifying whether a pre-tightening condition exists using the second preset keyword; if it exists, the second load step is defaulted to be the effective load step for calculating the fatigue safety factor of the electric drive system; if it does not exist, the first load step is defaulted to be the effective load step for calculating the fatigue safety factor of the electric drive system.

[0075] The second preset keyword is a keyword used to identify the preload definition section, indicating the settings and parameters related to the preload in the file. For example, the second preset keyword is "pre".

[0076] Specifically, the system automatically scans .inp files for a second preset keyword (such as "pre") and matches it within the .inp files to identify whether a preload condition exists. If the keyword exists, the system is identified as having a preload condition, and the fatigue safety factor of the electric drive system is calculated starting from the second load step by default. If the keyword does not exist, the system is identified as having no preload condition, and the calculation starts from the first load step by default.

[0077] This application utilizes a method that automatically identifies preload conditions using a second preset keyword (such as "pre"), enabling intelligent judgment and setting of load steps. This significantly improves the automation and accuracy of fatigue safety factor calculations. It avoids errors that may arise from manual intervention, ensuring the consistency and reliability of the analysis process. Furthermore, by automatically adjusting the starting point of the effective load step based on the presence or absence of preload conditions, the calculation becomes more flexible and efficient, better adapting to the analysis needs under different operating conditions and providing strong support for fatigue life assessment of electric drive systems.

[0078] In some embodiments of this application, the default number of cycles is 1,000,000, and the preset fatigue analysis software is FEMFAT software.

[0079] In fatigue analysis, the number of cycles refers to the number of times a material or structure is subjected to repeated cyclic loads, which is used to evaluate its fatigue life and reliability.

[0080] Specifically, the program's default loop count is 1,000,000. To change the loop count, you can customize the settings in the front-end window. For example, you can set the loop count to 500,000, 2,000,000, or other reasonable numbers as needed; there are no specific restrictions.

[0081] This application significantly improves the flexibility and adaptability of fatigue analysis by setting a default cycle count of 1,000,000 and combining it with a customizable cycle count setting function. Engineers can quickly adjust the cycle count according to specific material or operating condition requirements without complex operations, thereby efficiently assessing the fatigue life and reliability of materials or structures. This flexible configuration not only improves analysis efficiency but also enhances the software's usability and user-friendliness.

[0082] This application also provides a device for calculating the fatigue safety factor of a vehicle electric drive system, as detailed below. Figure 2 The device 200 includes: a finite element modeling and assembly module 210, a load step generation module 220, a processing module 230, and a calculation module 240.

[0083] The finite element modeling and assembly module 210 is used to perform finite element modeling and assembly of the vehicle's reducer housing assembly, and assign material properties to the vehicle's parts, including the reducer housing, suspension brackets, and bolts. The load step generation module 220 is used to apply bolt preload and M suspension loads at the vehicle's reducer housing suspension points, and generate M+1 load steps, where M is a positive integer. The processing module 230 is used to generate an .inp file based on the M+1 load steps, solve for the stress results of the reducer housing under various conditions, and save it as an .odb file. The calculation module 240 is used to calculate the fatigue safety factor of the vehicle's electric drive system based on the .odb file.

[0084] In some embodiments of this application, the calculation module 240 calculates the fatigue safety factor of the vehicle's electric drive system based on the .odb file. Specifically, it is used to: select the .odb file in the front-end window; obtain the corresponding .inp file based on the .odb file, parse the .inp file, and match it in the .inp file using a first preset keyword to obtain the correspondence between parts and materials; match it in the .inp file using a second preset keyword and preset the upper and lower amplitude stresses for each fatigue condition based on the matching results; set multiple parameter types, including multiple types of solution type, input result file type, influence parameter, and storage file type; input a custom number of loops through the front-end window, where the program defaults to N loops, where N is a positive integer; and after setting the number of loops, submit it to the preset fatigue analysis software to continuously calculate the fatigue safety factor of the electric drive system under multiple fatigue conditions.

[0085] In some embodiments of this application, the calculation module 240 selects a .odb file in the front-end window, specifically for: selecting and / or entering the file path and name of the .odb file in the front-end window.

[0086] In some embodiments of this application, the calculation module 240 performs matching in the .inp file using a first preset keyword to obtain the correspondence between parts and materials. Specifically, it is used to: automatically locate the content of the definition section of parts and materials in the .inp file using the first preset keyword, read the correspondence between parts and materials, and automatically match the material files in the material library through the configuration relationship of material names.

[0087] In some embodiments of this application, the calculation module 240, after matching the .inp file with the second preset keyword, is specifically used to: identify whether there is a pre-tightening condition by the second preset keyword; if it exists, the second load step is defaulted to be the effective load step for calculating the fatigue safety factor of the electric drive system; if it does not exist, the first load step is defaulted to be the effective load step for calculating the fatigue safety factor of the electric drive system.

[0088] In some embodiments of this application, the calculation module 240 has a default loop count of 1,000,000 and the preset fatigue analysis software is FEMFAT software.

[0089] It should be noted that for details not disclosed in the vehicle electric drive system fatigue safety factor calculation device of this application embodiment, please refer to the details disclosed in the vehicle electric drive system fatigue safety factor calculation method of this application embodiment, which will not be repeated here.

[0090] Corresponding to the above embodiments, this application also provides an electronic device, specifically referring to... Figure 3The electronic device 300 includes: a memory 310, a processor 320, and a computer program stored in the memory 310 and capable of running on the processor 320. The processor 320 executes the program to implement the aforementioned method for calculating the fatigue safety factor of the vehicle electric drive system.

[0091] This application also provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the aforementioned method for calculating the fatigue safety factor of a vehicle electric drive system.

[0092] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the aforementioned method for calculating the fatigue safety factor of a vehicle electric drive system.

[0093] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0094] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0095] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0096] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0097] Any process or method described in the flowchart or otherwise herein is to be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0098] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0099] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0100] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it includes one or a combination of the steps of the method embodiments.

[0101] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0102] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

[0103] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.

[0104] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for calculating the fatigue safety factor of a vehicle electric drive system, characterized in that, include: Finite element modeling and assembly of the vehicle's reducer housing assembly are performed, and material properties are assigned to the vehicle's parts, including the reducer housing, suspension bracket, and bolts. A bolt preload and M suspension loads are applied at the vehicle's reducer housing mounting point, and M+1 load steps are generated for each load, where M is a positive integer. A load file is generated based on the M+1 load steps, and the stress results of the reducer housing of the vehicle under various working conditions are solved based on the load file and saved as a .odb file. The fatigue safety factor of the vehicle's electric drive system is calculated based on the .odb file.

2. The method for calculating the fatigue safety factor of a vehicle electric drive system according to claim 1, characterized in that, The calculation of the fatigue safety factor of the vehicle's electric drive system based on the .odb file includes: In the front-end window, select the .odb file; Obtain the corresponding .inp file from the .odb file, parse the .inp file, and match the .inp file using the first preset keyword to obtain the correspondence between the part and the material; The second preset keyword is used to match the values ​​in the .inp file, and the upper and lower amplitude stresses for each fatigue condition are preset according to the matching results. Multiple parameter types are set, including multiple types of solution type, input result file type, influencing parameters, and storage file type; The user can input a custom number of loops through the front-end window. The program defaults to N loops, where N is a positive integer. After setting the number of cycles, submit the results to the preset fatigue analysis software to continuously calculate the fatigue safety factor of the electric drive system under multiple fatigue conditions.

3. The method for calculating the fatigue safety factor of a vehicle electric drive system according to claim 2, characterized in that, In the front-end window, selecting the .odb file includes: In the front-end window, select and / or enter the file path and name of the .odb file.

4. The method for calculating the fatigue safety factor of a vehicle electric drive system according to claim 2, characterized in that, The step of matching the parts and materials in the .inp file using a first preset keyword includes: The system automatically locates the definition section of the part and material in the .inp file using the first preset keyword, reads the correspondence between the part and the material, and automatically matches the material file in the material library based on the configuration relationship of the material name.

5. The method for calculating the fatigue safety factor of a vehicle electric drive system according to claim 2, characterized in that, The process of matching the .inp file using the second preset keyword includes: The presence of a pre-tightening condition is identified by the second preset keyword. If it exists, the second load step is assumed to be the effective load step for calculating the fatigue safety factor of the electric drive system. If it does not exist, the first load step is assumed to be the effective load step for calculating the fatigue safety factor of the electric drive system.

6. The method for calculating the fatigue safety factor of a vehicle electric drive system according to claim 2, characterized in that, The default number of cycles is 1,000,000, and the preset fatigue analysis software is FEMFAT software.

7. A device for calculating the fatigue safety factor of a vehicle electric drive system, characterized in that, include: The finite element modeling and assembly module is used to perform finite element modeling and assembly of the vehicle's reducer housing assembly, and to assign material properties to the vehicle's parts, including the reducer housing, suspension brackets, and bolts. A load step generation module is used to apply bolt preload and M suspension loads at the gearbox housing mounting point of the vehicle, and generate M+1 load steps respectively, where M is a positive integer; The processing module is used to generate an .inp file based on the M+1 load steps, solve the stress results of the reducer housing of the vehicle under various working conditions, and save them as an .odb file; The calculation module is used to calculate the fatigue safety factor of the vehicle's electric drive system based on the .odb file.

8. An electronic device, characterized in that, include: The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the fatigue safety factor calculation method for a vehicle electric drive system as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the fatigue safety factor calculation method for a vehicle electric drive system as described in any one of claims 1-6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the fatigue safety factor calculation method for the vehicle electric drive system as described in any one of claims 1-6.

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