Vehicle body fatigue durability analysis method, device and equipment and storage medium

Abstract

The invention discloses a vehicle body fatigue durability analysis method, device and equipment and a storage medium, and relates to the technical field of vehicles, and the method comprises the steps: carrying out the hard point extraction of a finite element model of a vehicle body, and determining a plurality of hard points existing on the vehicle body; carrying out a load test on each hard point according to the channel sequence of the load road spectrum to generate a stress result file; determining load spectrum data according to the multi-body dynamic model of the vehicle body, the target virtual iteration mode and the vehicle body test data; and performing fatigue durability analysis according to the plurality of material set model files corresponding to the vehicle body sheet metal part, the load spectrum data, the stress result file and the stress life curve of each material set model file to obtain a fatigue durability analysis result. Through the above mode and the automatic fatigue analysis process, the workload of personnel is effectively reduced, the virtual simulation efficiency and the automation degree of the fatigue durability of the vehicle body are improved, the fatigue simulation of the vehicle body is more standardized, and the fatigue simulation precision and consistency are effectively improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a vehicle body fatigue durability analysis method, device, equipment and storage medium. Background Art

[0002] During driving, the car will be subjected to cyclic dynamic loads from the road surface, and the stress generated will cause fatigue damage to the car body. When the damage accumulates to a certain extent, fatigue cracking will occur. The car body is an important part of the vehicle, and the reliability of its structure is directly related to the safety and health of the driver and passengers. At present, the fatigue durability verification methods of the car body mainly include road durability tests, bench tests and virtual simulation verification of physical prototypes; with the continuous compression of the vehicle development cycle, virtual simulation verification is more important in the car body design stage. The traditional car body fatigue analysis cycle is long, the workload is huge, it is easy to make mistakes, it requires repeated inspections, it takes a long time, and the analysis efficiency is low due to the difference in the ability of engineers. Summary of the invention

[0003] The main purpose of this application is to provide a vehicle body fatigue durability analysis method, device, equipment and storage medium, aiming to solve the technical problem of how to improve the efficiency and automation of virtual simulation of vehicle body fatigue durability.

[0004] To achieve the above purpose, the present application proposes a vehicle body fatigue durability analysis method, which includes:

[0005] Extract hard points from the finite element model of the vehicle body and determine the multiple hard points on the vehicle body;

[0006] Carry out load test on each hard point according to the channel sequence of load spectrum and generate stress result file;

[0007] Determine load spectrum data based on the multi-body dynamics model of the vehicle body, the target virtual iteration method and the vehicle body test data;

[0008] Fatigue durability analysis is performed based on multiple material set model files corresponding to the body sheet metal parts, the load spectrum data, the stress result file and the stress-life curve of each material set model file to obtain a fatigue durability analysis result of the body.

[0009] In one embodiment, before the step of extracting hard points from the finite element model of the vehicle body and determining a plurality of hard points on the vehicle body, the step further includes:

[0010] Performing finite element modeling of the vehicle body according to the vehicle body design parameters to generate a first vehicle body model;

[0011] Update the part name of each component in the first vehicle body model according to the material grade and material thickness corresponding to each part number to obtain a second vehicle body model;

[0012] The material properties of the components in the second vehicle body model are associated according to the local material library to obtain a finite element model of the vehicle body.

[0013] In one embodiment, the step of performing a load test on each hard point according to the channel sequence of the load path spectrum and generating a stress result file comprises:

[0014] Apply unit loads in multiple preset directions of each hard point according to the channel sequence of the load path spectrum to obtain unit load information;

[0015] Creating a plurality of working conditions corresponding to each hard point according to the unit load information and the channel sequence of the load spectrum;

[0016] The inertia release condition is solved according to the multiple working conditions corresponding to each hard point, and the stress result file is generated.

[0017] In one embodiment, the step of determining the load spectrum data according to the multi-body dynamics model of the vehicle body, the target virtual iteration method and the vehicle body test data comprises:

[0018] Inputting the initial driving load signal into the multi-body dynamics model of the vehicle body to obtain a signal response;

[0019] Performing error calculation based on the signal response and a target signal in the vehicle body test data to obtain a root mean square error;

[0020] When the error root mean square does not meet the preset requirement, iterative updating is performed according to the target virtual iteration mode, and load spectrum data is determined based on the iteration result.

[0021] In one embodiment, the step of performing iterative updating according to the target virtual iteration mode and determining load spectrum data based on the iteration result includes:

[0022] Determining an iterative load signal according to the target virtual iteration mode;

[0023] Inputting the iterative load signal into the multi-body dynamics model to obtain an iterative response;

[0024] Performing error calculation based on the iterative response signal and the target signal in the vehicle body test data to obtain an iterative root mean square;

[0025] When the iterative root mean square meets a preset requirement, load spectrum data is determined according to the iterative load signal.

[0026] In one embodiment, before the step of performing fatigue durability analysis according to the plurality of material set model files corresponding to the body sheet metal parts, the load spectrum data, the stress result file, and the stress life curve of each material set model file to obtain the fatigue durability analysis result of the body, the step further includes:

[0027] Get the part names of each component in the finite element model;

[0028] Determine the material grade of each body sheet metal part according to the part name of each component;

[0029] The body sheet metal parts are classified according to their material grades, and multiple material set model files corresponding to the body sheet metal parts are created based on the classification results.

[0030] In one embodiment, the step of performing fatigue durability analysis according to the plurality of material set model files corresponding to the body sheet metal parts, the load spectrum data, the stress result file, and the stress life curve of each material set model file to obtain the fatigue durability analysis result of the body includes:

[0031] Generate fatigue solution files for each load spectrum according to multiple material set model files corresponding to the body sheet metal parts, the load spectrum data, and the stress result files;

[0032] Calculate the fatigue solution file of each load road spectrum and the stress-life curve corresponding to each material set model file to obtain the fatigue solution file of each road surface;

[0033] According to the fatigue solution files of each road surface, the number of cycles is superimposed to determine the total damage value of the vehicle body;

[0034] A fatigue durability analysis result of the vehicle body is obtained according to the total damage value of the vehicle body.

[0035] In addition, to achieve the above-mentioned purpose, the present application also proposes a vehicle body fatigue and durability analysis device, the vehicle body fatigue and durability analysis device comprising:

[0036] An extraction module is used to extract hard points from the finite element model of the vehicle body and determine multiple hard points existing on the vehicle body;

[0037] The test module is used to perform load tests on each hard point according to the channel sequence of the load path spectrum and generate stress result files;

[0038] A processing module, for determining load spectrum data according to a multi-body dynamics model of a vehicle body, a target virtual iteration method and vehicle body test data;

[0039] The analysis module is used to perform fatigue durability analysis based on multiple material set model files corresponding to the body sheet metal parts, the load spectrum data, the stress result files and the stress life curves of each material set model file to obtain the fatigue durability analysis results of the body.

[0040] In addition, to achieve the above-mentioned purpose, the present application also proposes a vehicle body fatigue and durability analysis device, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, and the computer program is configured to implement the steps of the vehicle body fatigue and durability analysis method as described above.

[0041] In addition, to achieve the above-mentioned purpose, the present application also proposes a storage medium, which is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by the processor, the steps of the vehicle body fatigue durability analysis method described above are implemented.

[0042] In addition, to achieve the above-mentioned purpose, the present application also provides a computer program product, which includes a computer program, and when the computer program is executed by a processor, the steps of the vehicle body fatigue durability analysis method as described above are implemented.

[0043] This application determines multiple hard points on the body by extracting hard points from the finite element model of the body; performs load tests on each hard point according to the channel order of the load spectrum to generate a stress result file; determines the load spectrum data according to the multi-body dynamics model of the body, the target virtual iteration method and the body test data; performs fatigue durability analysis according to the multiple material set model files corresponding to the body sheet metal parts, the load spectrum data, the stress result files and the stress life curves of each material set model file to obtain the fatigue durability analysis results of the body. Through the above method, fatigue durability analysis is performed according to the stress result files generated after the load test, the load spectrum data, the multiple material set model files corresponding to the body sheet metal parts and the stress life curves of each material set model file, and accurate fatigue durability analysis results can be obtained. Through the automated fatigue analysis process, the workload of personnel is effectively reduced, the efficiency and automation of the virtual simulation of the fatigue durability of the body are improved, the fatigue simulation of the body is made more standardized, and the fatigue simulation accuracy and consistency are effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0045] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0046] Figure 1 A schematic diagram of a process flow provided for the first embodiment of the vehicle body fatigue durability analysis method of the present application;

[0047] Figure 2 A schematic diagram of a virtual iteration process of a vehicle body fatigue durability analysis method provided in Example 1 of the present application;

[0048] Figure 3 A schematic diagram of a force-time displacement signal curve of a vehicle body fatigue durability analysis method provided in Example 1 of the present application;

[0049] Figure 4 A schematic diagram of a process flow provided for the second embodiment of the vehicle body fatigue durability analysis method of the present application;

[0050] Figure 5 A schematic diagram of a process flow provided for the third embodiment of the vehicle body fatigue durability analysis method of the present application;

[0051] Figure 6 A schematic diagram of a simplified process of a vehicle body fatigue durability analysis method provided in Example 3 of the present application;

[0052] Figure 7 This is a schematic diagram of the module structure of the vehicle body fatigue and durability analysis device according to an embodiment of the present application;

[0053] Figure 8 This is a schematic diagram of the equipment structure of the hardware operating environment involved in the vehicle body fatigue durability analysis method in the embodiment of the present application.

[0054] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0055] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0056] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0057] The main solution of the embodiment of the present application is: to extract hard points from the finite element model of the vehicle body and determine multiple hard points on the vehicle body; to perform load tests on each hard point according to the channel order of the load road spectrum and generate a stress result file; to determine the load spectrum data according to the multi-body dynamics model of the vehicle body, the target virtual iteration method and the vehicle body test data; to perform fatigue durability analysis according to multiple material set model files corresponding to the vehicle body sheet metal parts, the load spectrum data, the stress result file and the stress-life curves of each material set model file to obtain the fatigue durability analysis results of the vehicle body.

[0058] During driving, the car will be subjected to cyclic dynamic loads from the road surface, and the stress generated will cause fatigue damage to the car body. When the damage accumulates to a certain extent, fatigue cracking will occur. The car body is an important part of the vehicle, and the reliability of its structure is directly related to the safety and health of the driver and passengers. At present, the fatigue durability verification methods of the car body mainly include road durability tests, bench tests and virtual simulation verification of physical prototypes; with the continuous compression of the vehicle development cycle, virtual simulation verification is more important in the car body design stage. The traditional car body fatigue analysis cycle is long, the workload is huge, it is easy to make mistakes, it requires repeated inspections, it takes a long time, and the analysis efficiency is low due to the difference in the ability of engineers.

[0059] The present application provides a solution. By performing fatigue durability analysis based on the stress result file generated after the load test, load spectrum data, multiple material set model files corresponding to the body sheet metal parts, and stress-life curves of each material set model file, accurate fatigue durability analysis results can be obtained. Through the automated fatigue analysis process, the workload of personnel is effectively reduced, the efficiency and automation level of virtual simulation of body fatigue durability are improved, the body fatigue simulation is made more standardized, and the fatigue simulation accuracy and consistency are effectively improved.

[0060] It should be noted that the execution subject of this embodiment may be a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or a vehicle body fatigue and durability analysis device capable of realizing the above functions, etc. The following takes the vehicle body fatigue and durability analysis device as an example of the execution subject to illustrate this embodiment and the following embodiments.

[0061] Based on this, the present application embodiment provides a vehicle body fatigue durability analysis method, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the vehicle body fatigue durability analysis method of the present application.

[0062] In this embodiment, the vehicle body fatigue durability analysis method includes steps S10 to S40:

[0063] Step S10, extracting hard points from the finite element model of the vehicle body to determine a plurality of hard points on the vehicle body.

[0064] It should be noted that the finite element model of the car body is generated through finite element modeling based on the car body design parameters, includes updated part names, and assigns material properties to each component; hard points refer to important connection points and stress points on the car body, including but not limited to suspension points, engine mounting points, steering system connection points, etc. Hard points are subject to large dynamic loads during vehicle driving and are therefore key areas for fatigue durability analysis.

[0065] It is understandable that when fatigue durability analysis is required for the vehicle body, the hard point node information is extracted from the finite element model of the vehicle body, multiple hard points on the vehicle body are identified, and the positions of each hard point are marked and the hard point numbers are fixed. In this embodiment, the starting number can be 1001 or other starting numbers, which is not limited in this embodiment.

[0066] In a feasible implementation manner, before step S10, steps A11 to A13 may be included:

[0067] Step A11, performing finite element modeling of the vehicle body according to the vehicle body design parameters to generate a first vehicle body model.

[0068] Step A12: updating the part name of each component in the first vehicle body model according to the material grade and material thickness corresponding to each part number, so as to obtain a second vehicle body model.

[0069] Step A13: Associating material properties of components in the second vehicle body model according to the local material library to obtain a finite element model of the vehicle body.

[0070] It should be noted that the body design parameters include but are not limited to the vehicle's CATIA (Computer-Aided Three-Dimensional Interactive Application) model. The vehicle's CATIA model includes but is not limited to design parameter information such as body sheet metal, welding points, welding seams, structural adhesives, vehicle counterweight mass information, component part numbers, material grades, and material thickness BOM (Bill of Materials) table.

[0071] It can be understood that based on the body design parameters, the body finite element modeling is performed through the finite element pre-processing software Ansa, the sheet metal parts are modeled using 2D shell elements, the welds and adhesives are modeled using Rbe3+Hex+Rbe3 units, the Beam and Rbe2 combination (Rbe2-Cbeam-Rbe2) is used to simulate the bolt connection relationship, and the mass unit with the unit type of CONM2 is established according to the vehicle counterweight mass information, thereby obtaining the first body model.

[0072] In the specific implementation, multiple part numbers included in the first body model are determined according to the body design parameters, and the material grade and material thickness corresponding to each part number are determined. The renaming and automatic material assignment of each component in the first body model are realized based on the Ansa software through the Python secondary development language. The secondary development tool automatically updates the part names of each component in the model by scanning the material grade and thickness corresponding to the corresponding part number in the BOM. The updated part name format is "Part Number_Material Grade_Thickness". The first body model after the name update is the second body model.

[0073] It should be noted that after obtaining the second vehicle body model, the local material library is imported through Material DB, and the material properties in the material library are automatically associated according to the material brand name in the component, so as to obtain a finite element model associated with the material properties. Material DB is a material database management system, which is usually used in CAD / CAE (computer-aided design / computer-aided engineering) software to help users manage and use material property data. In this embodiment, Material DB is used to store and manage the physical and mechanical properties of various materials, such as elastic modulus, Poisson's ratio, yield strength, density, etc.

[0074] Step S20, performing load tests on each hard point according to the channel sequence of the load path spectrum, and generating a stress result file.

[0075] It should be noted that the channel sequence of the load spectrum refers to the order and combination of each load channel when conducting a multi-channel load test. In the fatigue durability analysis of the vehicle body, the load spectrum usually contains multiple channels, each of which represents a specific load type or direction. Based on the channel sequence of the load spectrum, the secondary development tool is used to apply unit loads in six directions of each hard point and create working conditions. After the working conditions are established, a quasi-static inertia release solution calculation is performed to generate a stress result file for the unit load.

[0076] Step S30 , determining load spectrum data according to the multi-body dynamics model of the vehicle body, the target virtual iteration method and the vehicle body test data.

[0077] It should be noted that the multi-body dynamics model is a mathematical model used to describe and analyze the motion and dynamic behavior of complex mechanical systems. In this embodiment, the multi-body dynamics model is used to simulate the dynamic response of the vehicle under different road conditions; the target virtual iteration method refers to a method of converting test data into load spectrum data through virtual simulation and iterative calculation, and adjusting the input load signal through multiple iterations so that the output response of the multi-body dynamics model is consistent with the target signal in the test data; the body test data refers to the dynamic response data of the vehicle under different road conditions obtained through actual tests, including but not limited to the six-component force, acceleration and strain of the wheel center; the load spectrum data refers to the driving load signal input into the multi-body dynamics model at the end of the iteration. In this embodiment, the body test data is obtained through a durability road test at a vehicle test site, and the data is recorded using sensors (such as accelerometers, force sensors, etc.).

[0078] In a feasible implementation, step S30 may include steps B11 to B13:

[0079] Step B11, inputting the initial driving load signal into the multi-body dynamics model of the vehicle body to obtain a signal response.

[0080] Step B12, performing error calculation based on the signal response and the target signal in the vehicle body test data to obtain a root mean square error.

[0081] Step B13, when the root mean square error does not meet the preset requirement, iterative update is performed according to the target virtual iteration mode, and load spectrum data is determined based on the iteration result.

[0082] It should be noted that the multi-body dynamics model is used to convert the shaft head acceleration signal into an external force load signal through the target virtual iteration method. The specific process is as follows: Figure 2 As shown, the target virtual iteration method regards the multi-body dynamics model established by the multi-body software Adams as a reversible linear mathematical system, which can be represented by a transfer function F. By inputting the initial driving load signal u0, the driving virtual system obtains the output signal response y0, and y0 is compared with the acceleration signal ym measured in the vehicle body test data to obtain the root mean square error between the two. If the root mean square error does not meet the preset requirements, the iteration continues. At the end of the iteration, the driving load signal input into the multi-body dynamics model is used as the load spectrum data. In this embodiment, the target signal refers to the measured signal corresponding to the signal response in the vehicle body test data; the preset requirement refers to the root mean square error being less than the set error threshold.

[0083] In a feasible implementation, step B13 may include steps C11 to C14:

[0084] Step C11, determining an iterative load signal according to the target virtual iteration mode.

[0085] Step C12: inputting the iterative load signal into the multi-body dynamics model to obtain an iterative response signal.

[0086] Step C13, performing error calculation based on the iterative response signal and the target signal in the vehicle body test data to obtain an iterative root mean square.

[0087] Step C14, when the iterative root mean square meets the preset requirement, determine the load spectrum data according to the iterative load signal.

[0088] It should be noted that the driving load signal input during the next iteration is determined according to the target virtual iteration method: u1=u0+F-1·(ym-y0), and then u1 is applied to the multi-body dynamics model to obtain the response signal y1 output by the model, and virtual iteration is performed in this way. In this embodiment, the iterative load signal refers to the driving load signal input during iteration; the iterative response signal refers to the response signal output by the model during iteration.

[0089] It is understandable that the error calculation is performed based on the iterative response signal and the corresponding target signal in the vehicle body test data to obtain the root mean square error between the nth iteration result and the target signal. In this embodiment, the iterative root mean square refers to the root mean square error calculated after the nth iteration.

[0090] In a specific implementation, when the iterative root mean square meets the preset requirements, the iteration ends, and the iterative load signal input at the end is used as the load spectrum data for the vehicle body fatigue durability analysis. In this embodiment, the file format of the load spectrum data is generally .s3t or .rsp. It is recommended to use the .rsp format in the FEMFAT ChannelMAX module, such as Figure 3 Shown are the force (torque)-time signal curves of different channels in a certain road spectrum.

[0091] Step S40, performing fatigue durability analysis according to a plurality of material set model files corresponding to the body sheet metal parts, the load spectrum data, the stress result file and the stress life curve of each material set model file to obtain a fatigue durability analysis result of the body.

[0092] It should be noted that each body sheet metal part is classified according to its material grade and placed into different sets according to its material grade, thereby obtaining multiple material set model files corresponding to the body sheet metal parts, and each material set model file includes all body sheet metal parts under the same material grade. The stress-life curve of each material set model file refers to the SN curve of the corresponding material automatically matched according to the material set model. The SN curve is a commonly used method to represent the fatigue performance of materials. It describes the relationship between the stress amplitude (Stress Amplitude, S) and the fatigue life (Number of Cycles to Failure, N) of the material under cyclic load.

[0093] It can be understood that a fatigue solution file for each load spectrum is generated based on multiple material set model files, load spectrum data and stress result files corresponding to the body sheet metal parts, and the stress-life curve (i.e., SN curve) of the corresponding material is automatically matched according to the multiple material set model files. The calculation is submitted, and after the solution is completed, the number of cycles is automatically superimposed to calculate the total damage and evaluate the results, thereby obtaining the fatigue durability analysis results of the body.

[0094] In a feasible implementation manner, before step S40, steps D11 to D13 may be included:

[0095] Step D11, obtaining the part name of each component in the finite element model.

[0096] Step D12, determining the material grade of each body sheet metal component according to the part name of each component.

[0097] Step D13 , classifying the body sheet metal parts according to their material grades, and creating a plurality of material set model files corresponding to the body sheet metal parts based on the classification results.

[0098] It should be noted that the material grades of multiple body sheet metal parts in the body are obtained by identifying the part names of each component in the finite element model and identifying the material grades in the part name "Part Number_Material Grade_Thickness". A set (i.e., SET set) with the same name as the material grade is automatically created, and the part mesh units with the same material grade are placed in the set. The sets are numbered starting from 1, and all part names are scanned until all body sheet metal parts are placed in different sets according to the material grades, thereby obtaining multiple material set model files corresponding to the body sheet metal parts.

[0099] This embodiment determines multiple hard points on the vehicle body by extracting hard points from the finite element model of the vehicle body; performs load tests on each hard point according to the channel order of the load spectrum to generate a stress result file; determines the load spectrum data according to the multi-body dynamics model of the vehicle body, the target virtual iteration method and the vehicle body test data; performs fatigue durability analysis according to multiple material set model files corresponding to the vehicle body sheet metal parts, the load spectrum data, the stress result files and the stress life curves of each material set model file to obtain the fatigue durability analysis results of the vehicle body. In the above manner, fatigue durability analysis is performed according to the stress result files, load spectrum data, multiple material set model files corresponding to the vehicle body sheet metal parts and the stress life curves of each material set model file generated after the load test, and accurate fatigue durability analysis results can be obtained. Through the automated fatigue analysis process, the workload of personnel is effectively reduced, the virtual simulation efficiency and automation degree of vehicle body fatigue durability are improved, the vehicle body fatigue simulation is more standardized, and the fatigue simulation accuracy and consistency are effectively improved.

[0100] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction, and will not be repeated in the following. Figure 4 In the vehicle body fatigue durability analysis method, step S20 further includes steps S21 to S23:

[0101] Step S21 , applying unit loads in multiple preset directions of each hard point according to the channel sequence of the load path spectrum to obtain unit load information.

[0102] It should be noted that the unit load is applied along the six preset directions of each hard point based on the sequence of the load spectrum channel using the secondary development tool to obtain the displacement, strain, stress and other response results of each hard point under the unit load. In this embodiment, the key code of the loading force of a single hard point is as follows: the first column is the loading type, the load type of the three translational degrees of freedom is force, the load type of the three rotational degrees of freedom is torque, the second column is the load number, corresponding to the load spectrum signal channel, the third column is the node number, and the fourth column is the size of the loading force or torque, which is 1 here. The last three columns correspond to X / Y / Z or Rx / Ry / Rz, 1 indicates that the direction is activated, and 0 indicates that it is not activated. The automatic loading of all nodes is realized through the for loop statement. The unit load information includes the displacement, strain, and stress response results of each hard point under the unit load, the type, number, node number, load size, and direction information of each load.

[0103] FOECE110011.1.0.0.

[0104] FOECE210011.0.1.0.

[0105] FOECE310011.0.0.1.

[0106] MOMENT410011.1.0.0.

[0107] MOMENT51001 1.0.1.0.

[0108] MOMENT61001 1.0.0.1.

[0109] Step S22: creating a plurality of working conditions corresponding to each hard point according to the unit load information and the channel sequence of the load spectrum.

[0110] It should be noted that, according to the channel order of the load spectrum, combined with the unit load information, the working conditions in each preset direction corresponding to each hard point are created, so as to obtain multiple working conditions corresponding to each hard point. In this embodiment, the key code for working condition creation is as follows: the first line is the working condition and serial number; the second line is the working condition name, named according to "node ID_load (F / M) direction (x / y / z)"; the third line is the load number, corresponding to the load number in the second column of 3.1, each node corresponds to six working conditions, and all working conditions are created through the for loop statement.

[0111] SUBCASE 1;

[0112] LABEL = 1001_Fx;

[0113] LOAD=1.

[0114] Step S23, solving the inertia release working condition according to the multiple working conditions corresponding to each hard point, and generating a stress result file.

[0115] It should be noted that after multiple working conditions corresponding to each hard point are established, static inertia release solution calculation is performed. The header file keywords are: SOL 101# call quasi-static linear solver;

[0116] STRESS=All#output stress;

[0117] PARAM, INREL, -2# uses inertia release solution. After the settings are completed, submit the calculation solution to obtain the solution file in op2 format. The solution file in op2 format is the stress result file of unit load.

[0118] In this embodiment, unit loads are applied in multiple preset directions of each hard point according to the channel sequence of the load spectrum to obtain unit load information; multiple working conditions corresponding to each hard point are created according to the unit load information and the channel sequence of the load spectrum; inertia release working conditions are solved according to the multiple working conditions corresponding to each hard point to generate a stress result file. In the above manner, an accurate stress result file can be generated.

[0119] Based on the first embodiment and / or the second embodiment of the present application, in the third embodiment of the present application, the same or similar contents as those of the above-mentioned first and second embodiments can refer to the above introduction, and will not be repeated later. Figure 5 , step S40, the vehicle body fatigue durability analysis method further includes steps S41 to S44:

[0120] Step S41, generating fatigue solution files for each load spectrum according to a plurality of material set model files corresponding to the body sheet metal parts, the load spectrum data, and the stress result files.

[0121] It should be noted that, according to the multiple material set model files, load spectrum data, and stress result files corresponding to the body sheet metal parts, calculation files for FEMFAT fatigue software can be generated. The key settings for secondary development are as follows: First, set the fatigue software to solve the multi-channel load spectrum module: SetValue{}{}MAXmod 1; automatically import multiple material set model files: SetValue{}{}FEinputFile. / Set_Model.bdf; automatically group the materials in multiple material set model files: setValue{}{}GUI_Group:Group{set_1-set1_name}; setValue{}{}GUI_Group:Group{set_2-set2_name}, where set_id and set_name must correspond to the ID and name of the set in the model. Automatically import the stress result file: setValue{}{}MaxStressInputFile 1. / Stress_result.op2; automatically import a load spectrum data: setValue{}{}MaxHistoryInputFile. / RLDA01.rsp. In this embodiment, the calculation file solved by the FEMFAT fatigue software is the fatigue solution file of each load path spectrum.

[0122] Step S42, calculating according to the fatigue solution file of each load road spectrum and the stress-life curve corresponding to each material set model file to obtain the fatigue solution file of each road surface.

[0123] It should be noted that the SN curve of the corresponding material set is automatically imported, and the material card format is .ffd, setValue{}{}MateriaReadFile. / set1_name_fat.ffd; setValue{}{}MateriaReadFile. / set2_name_fat.ffd. Associate the imported material card with the model files of each material set grouped previously, setValue{}{}GUI_Group:Group{set_1-set_name(MOD.)}; setValue{}{}FatParamMaterial{set_1-Mat_set1_name}, and automatically output the result format in combination with the fatigue solution file of each load road spectrum. For example, setValue{}{}OutputFile RLDA01.h3d corresponds to the single cycle result file of the stone road. At this point, the fatigue solution file of a single road surface is automatically generated. The fatigue solution files of each road surface are generated by scanning the fatigue solution files of each load road spectrum.

[0124] Step S43, superimposing the number of cycles according to the fatigue solution files of each road surface to determine the total damage value of the vehicle body.

[0125] It should be noted that the fatigue solution files of each road surface are superimposed on the number of cycles of different road surfaces. The key code is setValue{}{}GUI_ResManager:ScalingFactor RLDA_ID Cyc_num, where RLDA_ID represents the road spectrum number and Cyc_num represents the number of cycles. Finally, the total damage value of the vehicle body can be calculated.

[0126] Step S44, obtaining a fatigue durability analysis result of the vehicle body according to the total damage value of the vehicle body.

[0127] It should be noted that the fatigue durability of the vehicle body is determined according to the total damage value of the vehicle damage, thereby obtaining the fatigue durability analysis result. In this embodiment, when the total damage value of the vehicle damage is greater than 1, it indicates that the vehicle body has fatigued and failed.

[0128] This embodiment generates fatigue solution files for each load road spectrum according to multiple material set model files corresponding to the body sheet metal parts, the load spectrum data, and the stress result files; calculates according to the fatigue solution files of each load road spectrum and the stress-life curves corresponding to each material set model file to obtain fatigue solution files for each road surface; superimposes the number of cycles according to the fatigue solution files of each road surface to determine the total damage value of the body; and obtains the fatigue durability analysis result of the body according to the total damage value of the body.

[0129] For example, to help understand the implementation process of the vehicle body fatigue durability analysis method obtained by combining the first embodiment and the second embodiment, please refer to Figure 6 , Figure 6 A brief flow chart of a vehicle body fatigue durability analysis method is provided, specifically:

[0130] The vehicle body fatigue durability analysis method of this embodiment specifically includes the following steps: 1. Automatically scan the material property information in the BOM according to the part number in the modeling stage, automatically update the material information and thickness information after the part number, and automatically assign material parameters according to the material name. 2. Automatically apply a unit load to the hard point position of the vehicle body connected to the chassis, and perform inertia release calculations as input for subsequent durability calculations. 3. Automatically create a set based on the material brand in the model, and put all grid units of the same material brand in the same set. 4. Automatically create a ffj format solution file that can be recognized by the fatigue software femfat, which is used to solve single damage of different road spectra. 5. Automatically superimpose the number of cycles of different road spectra, calculate the total damage, and evaluate the results. The method of this embodiment performs automated fatigue analysis on the vehicle body in the early stage of vehicle body design. Through secondary development tools, firstly, the part attribute names are automatically changed and the materials are assigned according to the BOM, the unit force is automatically loaded at the hard point position and the inertia release solution is calculated, the set is automatically created according to the material grade and the set model is output, and the fatigue solution file of each road spectrum is automatically created. After the solution is completed, the number of cycles is automatically superimposed and the total damage is calculated. By establishing a set of automated fatigue analysis processes, the workload is effectively reduced, the fatigue analysis efficiency is improved, the fatigue analysis process and steps are solidified, the body fatigue simulation is more standardized, and the fatigue simulation accuracy and consistency are effectively improved.

[0131] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the vehicle body fatigue durability analysis method of the present application. More simple transformations based on this technical concept are all within the protection scope of the present application.

[0132] This application also provides a vehicle body fatigue durability analysis device, please refer to Figure 7 , the vehicle body fatigue durability analysis device comprises:

[0133] The extraction module 10 is used to extract hard points from the finite element model of the vehicle body and determine a plurality of hard points existing on the vehicle body.

[0134] The test module 20 is used to perform a load test on each hard point according to the channel sequence of the load path spectrum and generate a stress result file.

[0135] The processing module 30 is used to determine the load spectrum data according to the multi-body dynamics model of the vehicle body, the target virtual iteration method and the vehicle body test data.

[0136] The analysis module 40 is used to perform fatigue durability analysis based on multiple material set model files corresponding to the body sheet metal parts, the load spectrum data, the stress result files and the stress life curves of each material set model file to obtain the fatigue durability analysis results of the body.

[0137] Optionally, the extraction module 10 is further used for:

[0138] Car body finite element modeling is performed according to car body design parameters to generate a first car body model; the part name of each component in the first car body model is updated according to the material grade and material thickness corresponding to each part number to obtain a second car body model; the material properties of each component in the second car body model are associated according to the local material library to obtain the finite element model of the car body.

[0139] Optionally, the test module 20 is further used for:

[0140] Unit loads are applied in multiple preset directions of each hard point according to the channel sequence of the load path spectrum to obtain unit load information; multiple working conditions corresponding to each hard point are created according to the unit load information and the channel sequence of the load path spectrum; inertia release working conditions are solved according to the multiple working conditions corresponding to each hard point to generate a stress result file.

[0141] Optionally, the processing module 30 is further used for:

[0142] The initial driving load signal is input into the multi-body dynamics model of the vehicle body to obtain a signal response; the error is calculated according to the signal response and the target signal in the vehicle body test data to obtain the root mean square error; when the root mean square error does not meet the preset requirements, iterative update is performed according to the target virtual iteration method, and the load spectrum data is determined based on the iteration result.

[0143] Optionally, the processing module 30 is further used for:

[0144] An iterative load signal is determined according to the target virtual iteration method; the iterative load signal is input into the multi-body dynamics model to obtain an iterative response; an error is calculated according to the iterative response signal and a target signal in the vehicle body test data to obtain an iterative root mean square; when the iterative root mean square meets a preset requirement, load spectrum data is determined according to the iterative load signal.

[0145] Optionally, the analysis module 40 is further configured to:

[0146] Obtain the part name of each component in the finite element model; determine the material grade of each body sheet metal part according to the part name of each component; classify the body sheet metal parts according to the material grade, and create multiple material set model files corresponding to the body sheet metal parts based on the classification results.

[0147] Optionally, the analysis module 40 is further configured to:

[0148] Generate fatigue solution files for each load road spectrum based on multiple material set model files corresponding to the body sheet metal parts, the load spectrum data, and stress result files; calculate based on the fatigue solution files for each load road spectrum and the stress-life curves corresponding to each material set model file to obtain fatigue solution files for each road surface; superimpose the number of cycles based on the fatigue solution files for each road surface to determine the total damage value of the body; and obtain fatigue durability analysis results of the body based on the total damage value of the body.

[0149] The vehicle body fatigue and durability analysis device provided by the present application adopts the vehicle body fatigue and durability analysis method in the above embodiment, and can solve the technical problem of how to improve the virtual simulation efficiency and automation degree of vehicle body fatigue and durability. Compared with the prior art, the beneficial effects of the vehicle body fatigue and durability analysis device provided by the present application are the same as the beneficial effects of the vehicle body fatigue and durability analysis method provided by the above embodiment, and the other technical features of the vehicle body fatigue and durability analysis device are the same as the features disclosed in the above embodiment method, which will not be repeated here.

[0150] The present application provides a vehicle body fatigue and durability analysis device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the vehicle body fatigue and durability analysis method in the above-mentioned embodiment one.

[0151] Reference below Figure 8 , which shows a schematic diagram of the structure of a vehicle body fatigue and durability analysis device suitable for implementing the embodiment of the present application. The vehicle body fatigue and durability analysis device in the embodiment of the present application may include but is not limited to mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 8 The vehicle body fatigue durability analysis device shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0152] like Figure 8As shown, the vehicle body fatigue and durability analysis device may include a processing device 1001 (such as a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM: Read Only Memory) 1002 or a program loaded from a storage device 1003 to a random access memory (RAM: Random Access Memory) 1004. In RAM1004, various programs and data required for the operation of the vehicle body fatigue and durability analysis device are also stored. The processing device 1001, ROM1002 and RAM1004 are connected to each other through a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to the I / O interface 1006: input devices 1007 including, for example, a touch screen, a touchpad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; output devices 1008 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; storage devices 1003 including, for example, a magnetic tape, a hard disk, etc.; and communication devices 1009. The communication device 1009 can allow the vehicle body fatigue and durability analysis device to communicate with other devices wirelessly or by wire to exchange data. Although the figure shows a vehicle body fatigue and durability analysis device with various systems, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems may be implemented or have alternatively.

[0153] In particular, according to the embodiments disclosed in the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication device, or installed from a storage device 1003, or installed from a ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present application are executed.

[0154] The vehicle body fatigue and durability analysis device provided by the present application adopts the vehicle body fatigue and durability analysis method in the above embodiment, which can solve the technical problem of how to improve the virtual simulation efficiency and automation degree of vehicle body fatigue and durability. Compared with the prior art, the beneficial effects of the vehicle body fatigue and durability analysis device provided by the present application are the same as the beneficial effects of the vehicle body fatigue and durability analysis method provided by the above embodiment, and the other technical features in the vehicle body fatigue and durability analysis device are the same as the features disclosed in the method of the previous embodiment, which will not be repeated here.

[0155] It should be understood that the various parts disclosed in this application can be implemented by hardware, software, firmware or a combination thereof. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0156] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0157] The present application provides a computer-readable storage medium having computer-readable program instructions (ie, computer programs) stored thereon, and the computer-readable program instructions are used to execute the vehicle body fatigue durability analysis method in the above-mentioned embodiment.

[0158] The computer-readable storage medium provided in the present application may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, systems or devices, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, system or device. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination of the above.

[0159] The computer-readable storage medium may be included in the vehicle body fatigue and durability analysis device; or may exist independently without being assembled into the vehicle body fatigue and durability analysis device.

[0160] The above-mentioned computer-readable storage medium carries one or more programs. When the above-mentioned one or more programs are executed by the vehicle body fatigue and durability analysis equipment, the vehicle body fatigue and durability analysis equipment: extracts hard points from the finite element model of the vehicle body to determine multiple hard points on the vehicle body; performs load tests on each hard point according to the channel sequence of the load road spectrum to generate a stress result file; determines the load spectrum data according to the multi-body dynamics model of the vehicle body, the target virtual iteration method and the vehicle body test data; performs fatigue durability analysis according to multiple material set model files corresponding to the vehicle body sheet metal parts, the load spectrum data, the stress result file and the stress-life curves of each material set model file to obtain the fatigue durability analysis result of the vehicle body.

[0161] Computer program code for performing the operations of the present application may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0162] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0163] The modules involved in the embodiments described in this application may be implemented by software or hardware, wherein the name of the module does not constitute a limitation on the unit itself in some cases.

[0164] The readable storage medium provided in this application is a computer-readable storage medium, which stores computer-readable program instructions (i.e., computer programs) for executing the above-mentioned vehicle body fatigue and durability analysis method, and can solve the technical problem of how to improve the efficiency and automation of virtual simulation of vehicle body fatigue and durability. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as the beneficial effects of the vehicle body fatigue and durability analysis method provided in the above-mentioned embodiment, and will not be elaborated here.

[0165] The present application also provides a computer program product, including a computer program, which implements the steps of the above-mentioned vehicle body fatigue durability analysis method when executed by a processor.

[0166] The computer program product provided by this application can solve the technical problem of how to improve the efficiency and automation of virtual simulation of vehicle body fatigue durability. Compared with the prior art, the beneficial effects of the computer program product provided by this application are the same as the beneficial effects of the vehicle body fatigue durability analysis method provided by the above embodiment, which will not be elaborated here.

[0167] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A vehicle body fatigue durability analysis method, characterized in that: The vehicle body fatigue durability analysis method comprises: Extract hard points from the finite element model of the vehicle body and determine the multiple hard points on the vehicle body; Carry out load test on each hard point according to the channel sequence of load spectrum and generate stress result file; Determine load spectrum data based on the multi-body dynamics model of the vehicle body, the target virtual iteration method and the vehicle body test data; Fatigue durability analysis is performed based on multiple material set model files corresponding to the body sheet metal parts, the load spectrum data, the stress result file and the stress-life curve of each material set model file to obtain a fatigue durability analysis result of the body.

2. The method according to claim 1, characterized in that Before the step of extracting hard points from the finite element model of the vehicle body and determining a plurality of hard points on the vehicle body, the method further includes: Performing finite element modeling of the vehicle body according to the vehicle body design parameters to generate a first vehicle body model; Update the part name of each component in the first vehicle body model according to the material grade and material thickness corresponding to each part number to obtain a second vehicle body model; The material properties of the components in the second vehicle body model are associated according to the local material library to obtain a finite element model of the vehicle body.

3. The method according to claim 1, characterized in that The step of performing a load test on each hard point according to the channel sequence of the load path spectrum and generating a stress result file comprises: Apply unit loads in multiple preset directions of each hard point according to the channel sequence of the load path spectrum to obtain unit load information; Creating a plurality of working conditions corresponding to each hard point according to the unit load information and the channel sequence of the load spectrum; The inertia release condition is solved according to the multiple working conditions corresponding to each hard point, and the stress result file is generated.

4. The method according to claim 1, characterized in that The step of determining the load spectrum data according to the multi-body dynamics model of the vehicle body, the target virtual iteration method and the vehicle body test data comprises: Inputting the initial driving load signal into the multi-body dynamics model of the vehicle body to obtain a signal response; Performing error calculation based on the signal response and a target signal in the vehicle body test data to obtain a root mean square error; When the error root mean square does not meet the preset requirement, iterative updating is performed according to the target virtual iteration mode, and load spectrum data is determined based on the iteration result.

5. The method according to claim 4, characterized in that The step of performing iterative updating according to the target virtual iteration mode and determining load spectrum data based on the iteration result includes: Determining an iterative load signal according to the target virtual iteration mode; Inputting the iterative load signal into the multi-body dynamics model to obtain an iterative response; Performing error calculation based on the iterative response signal and the target signal in the vehicle body test data to obtain an iterative root mean square; When the iterative root mean square meets a preset requirement, load spectrum data is determined according to the iterative load signal.

6. The method according to claim 1, characterized in that Before the step of performing fatigue durability analysis according to the plurality of material set model files corresponding to the body sheet metal parts, the load spectrum data, the stress result files and the stress life curves of the material set model files to obtain the fatigue durability analysis result of the body, the step further includes: Get the part names of each component in the finite element model; Determine the material grade of each body sheet metal part according to the part name of each component; The body sheet metal parts are classified according to their material grades, and multiple material set model files corresponding to the body sheet metal parts are created based on the classification results.

7. The method according to any one of claims 1 to 6, characterized in that The step of performing fatigue durability analysis according to the plurality of material set model files corresponding to the body sheet metal parts, the load spectrum data, the stress result file and the stress life curve of each material set model file to obtain the fatigue durability analysis result of the body includes: Generate fatigue solution files for each load spectrum according to multiple material set model files corresponding to the body sheet metal parts, the load spectrum data, and the stress result files; Calculate the fatigue solution file of each load road spectrum and the stress-life curve corresponding to each material set model file to obtain the fatigue solution file of each road surface; According to the fatigue solution files of each road surface, the number of cycles is superimposed to determine the total damage value of the vehicle body; A fatigue durability analysis result of the vehicle body is obtained according to the total damage value of the vehicle body.

8. A vehicle body fatigue durability analysis device, characterized in that: The vehicle body fatigue durability analysis device comprises: An extraction module is used to extract hard points from the finite element model of the vehicle body and determine multiple hard points existing on the vehicle body; The test module is used to perform load tests on each hard point according to the channel sequence of the load path spectrum and generate stress result files; A processing module, for determining load spectrum data according to a multi-body dynamics model of a vehicle body, a target virtual iteration method and vehicle body test data; The analysis module is used to perform fatigue durability analysis based on multiple material set model files corresponding to the body sheet metal parts, the load spectrum data, the stress result files and the stress life curves of each material set model file to obtain the fatigue durability analysis results of the body.

9. A vehicle body fatigue durability analysis device, characterized in that: The vehicle body fatigue and durability analysis device comprises: a memory, a processor, and a vehicle body fatigue and durability analysis program stored in the memory and executable on the processor, wherein the vehicle body fatigue and durability analysis program is configured to implement the vehicle body fatigue and durability analysis method according to any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium stores a vehicle body fatigue and durability analysis program, and when the vehicle body fatigue and durability analysis program is executed by the processor, the vehicle body fatigue and durability analysis method according to any one of claims 1 to 7 is implemented.

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