Analysis method and system for carrying out durability simulation on processing defects

Abstract

The invention relates to an analysis method for carrying out durability simulation on machining defects, which comprises the following steps of: establishing an automobile part analysis model of an automobile part to be analyzed, and constructing different parts in the automobile part analysis model by adopting different grid forms; on the basis of the machining defect position of the to-be-analyzed automobile part, local mesh refinement is carried out on a corresponding defect area in the automobile part analysis model; and based on the refined defect area, outward expansion is carried out by taking the center position of the defect area as a starting point. According to the analysis method and system for performing durability simulation on the machining defects, local mesh refinement and elastic modulus gradient distribution are performed on the defect area of the automobile part analysis model, so that on one hand, the modeling process is simplified, and the complexity of performing targeted modeling on the defect area traditionally is reduced; the efficiency of model building and simulation analysis is improved, on the other hand, the obtained durability simulation result is highly matched with the actual failure behavior of the defective part, and the simulation precision is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of parts testing, and more specifically to an analysis method and system for simulating the durability performance of machining defects. Background Technology

[0002] Automotive parts, especially sheet metal brackets, undergo critical processes such as flanging, stamping, and bending during manufacturing. Due to limitations in process conditions and other factors, these parts are prone to inherent processing defects such as bending cracks, scratches, and warping during the manufacturing stage. To ensure part quality and reliability and prevent defective products from entering the market, accurate durability performance simulation analysis is crucial after the parts are manufactured.

[0003] In related technologies, when modeling automotive parts for durability performance simulation analysis, the parts are usually treated as perfect parts without any processing defects. Defects that may occur during actual processing are not considered, and existing processing defects on the parts are not effectively modeled. However, if processing defects are modeled specifically, factors such as the type, location, and size of the defects need to be considered. This modeling process is undoubtedly time-consuming and labor-intensive. But if the impact of processing defects is not considered, the durability performance simulation analysis results of automotive parts will be too high, affecting the accuracy of the simulation evaluation of the parts' durability performance and leading to safety risks in subsequent actual durability performance testing and use of the parts. Summary of the Invention

[0004] Therefore, this application provides an analysis method and system for simulating the durability performance of processing defects to solve the above problems.

[0005] In a first aspect, embodiments of this application provide an analysis method for simulating the durability performance of processing defects, comprising the following steps: An automotive part analysis model is established for the automotive parts to be analyzed, wherein different parts in the automotive part analysis model are constructed using different mesh formats; Based on the location of the machining defects in the automotive parts to be analyzed, local mesh refinement is performed on the corresponding defect areas in the automotive part analysis model; Based on the refined defect region, the elastic modulus is assigned to the mesh by expanding outward from the center of the defect region. The elastic modulus value at the center of the defect region is 0, the elastic modulus value at the edge of the defect region is close to the elastic modulus value of the defect-free region, and the elastic modulus value at the center of the defect region increases in a gradient from the edge of the defect region. Durability simulation analysis was performed on the automotive part analysis model after the elastic modulus was allocated.

[0006] In conjunction with the first aspect, in one embodiment, the mesh size of the defective region in the automotive part analysis model is 1 / 10 to 1 / 4 of the mesh size of the non-defective region.

[0007] In conjunction with the first aspect, in one embodiment, the gradient change of the elastic modulus value is distributed linearly from the center of the defect region in the automotive part analysis model to the edge.

[0008] In conjunction with the first aspect, in one implementation, different parts in the automotive parts analysis model are constructed using different mesh formats, specifically including: Bolted connections can be rigid or in the form of a 1D mesh. Sheet metal parts or connectors are presented in a 2D mesh format; Castings or parts with complex structures are presented in 3D mesh form.

[0009] In conjunction with the first aspect, in one implementation, after establishing the analysis model of the automotive part to be analyzed, the method further includes calibrating the automotive part analysis model through modal testing. Specifically, calibrating the automotive part analysis model through modal testing includes: Obtain the first modal frequency value of the automotive part analysis model and the measured modal frequency value of the automotive part to be analyzed; Calculate the relative error between the first modal frequency value and the measured modal frequency value; When the relative error is greater than or equal to the set first error value, adjust the automotive part analysis model until the error is less than the first error value.

[0010] In conjunction with the first aspect, in one embodiment, when the relative error is greater than or equal to a set first error value, the adjustment of the automotive part analysis model includes adjusting the connection method between different parts in the automotive part analysis model, adjusting the mesh type of the connection area in the automotive part analysis model, and adjusting the model parameters of the connection area in the automotive part analysis model.

[0011] In conjunction with the first aspect, in one implementation, after the refined defect region is expanded outward from the center of the defect region and given an elastic modulus with varying mesh gradient, the system further includes a calibration model of the automotive part after the elastic modulus allocation.

[0012] In conjunction with the first aspect, in one embodiment, the automotive part analysis model after calibrating the elastic modulus allocation specifically includes: Obtain the second modal frequency value of the automotive part analysis model after elastic modulus allocation; Calculate the relative error between the second modal frequency value and the measured modal frequency value; When the relative error is greater than or equal to the set second error value, adjust the elastic modulus distribution method until the error is less than the second error value.

[0013] In conjunction with the first aspect, in one embodiment, when the relative error is greater than or equal to a set second error value, the elastic modulus allocation method is adjusted until the error is less than the second error value. The elastic modulus adjustment method includes adjusting the elastic modulus value allocated to each refined mesh and the change value of the elastic modulus value between each refined mesh.

[0014] Secondly, embodiments of this application provide an analysis system for an analysis method of performing durability performance simulation on processing defects, comprising: The model building module is used to build an analysis model of the automotive parts to be analyzed. The attribute assignment module is used to refine the local mesh of the corresponding defect area in the automotive part analysis model. Based on the refined defect area, it expands outward from the center of the defect area and assigns an elastic modulus of gradient change to the mesh. Test module: Used to perform durability performance simulation analysis on the automotive part analysis model after elastic modulus allocation, and output the results.

[0015] The beneficial effects of the technical solutions provided in this application include: This method and system for durability simulation of machining defects simplifies the traditional modeling process by refining the local mesh and allocating the elastic modulus gradient in the defect area of ​​the automotive part analysis model. This reduces the complexity of traditional targeted modeling of defect areas and improves the efficiency of model building and simulation analysis. Furthermore, the obtained durability simulation results closely match the actual failure behavior of the defective parts, ensuring the accuracy of the simulation analysis. This provides a more reliable and convenient simulation approach for durability simulation analysis of machining defects in automotive parts. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the method flow of the present invention; Figure 2 This is a schematic diagram showing the fracture location of the license plate light bracket of the present invention during an actual durability test; Figure 3 This is a schematic diagram of the fracture location in the durability performance simulation of this invention without calibrating the license plate light bracket model; Figure 4 This is a schematic diagram illustrating the mesh refinement process of the license plate light bracket model according to the present invention; Figure 5 This is a schematic diagram showing the elastic modulus distribution of the license plate light bracket model of the present invention; Figure 6 A comparison diagram of modal frequency values ​​before and after calibration of the elastic model of the license plate light of the present invention; Figure 7 The image shows the results of a durability simulation analysis of the license plate light bracket model after the elastic modulus calibration of this invention. Figure 8 The figure shows the results of durability simulation analysis of the license plate light bracket model with uncalibrated elastic modulus according to the present invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0019] This application provides an analysis method for durability performance simulation of processing defects, including the following steps: Step 1: Establish an automotive part analysis model for the automotive part to be analyzed; The automotive part analysis model was established using finite element analysis software. Different parts in the automotive part analysis model were constructed using different mesh formats. Specifically: Bolted connections are either rigid or 1D mesh-like to ensure that the connection stiffness meets actual requirements. Sheet metal parts or connectors are presented in a 2D mesh format; Castings or parts with complex structures are made easier to capture geometric details using 3D meshes. Step 2: Calibrate the automotive part analysis model through modal testing; A. Obtain the first modal frequency value of the automotive part analysis model by performing modal analysis using finite element software; The measured modal frequencies of the automotive parts to be analyzed are obtained by conducting experimental modal tests using the hammer impact method or a sweep frequency vibration table. B. Calculate the relative error between the first modal frequency value and the measured modal frequency value; C. When the relative error is greater than or equal to the set first error value, adjust the automotive part analysis model until the error is less than the first error value.

[0020] Adjusting the automotive part analysis model can be done by: adjusting the connection method between different parts in the automotive part analysis model, adjusting the mesh type of the connection area of ​​the automotive part analysis model, and adjusting the model parameters of the connection area of ​​the automotive part analysis model.

[0021] The first error value is the acceptance standard for model accuracy. The modal error threshold for automotive parts is usually set at around 5%, which can be adjusted according to different parts and requirements. Specifically, when the relative error is ≥5%, it indicates that there is a significant distortion in the stiffness or mass distribution of the automotive part analysis model. If calibration is not performed, it will lead to a large deviation in the subsequent analysis results and affect the judgment of the fracture location.

[0022] By calibrating the automotive part analysis model through modal testing, it can be ensured that the model accurately reflects the physical properties of the automotive parts, thereby improving the accuracy of subsequent analyses.

[0023] Step 3: Identify the actual machining defect locations in the automotive part analysis model, and refine the local mesh in the corresponding defect area within the automotive part analysis model; The mesh size of the defective region is 1 / 10 to 1 / 4 of the mesh size of the defect-free region.

[0024] Step 4: Based on the refined defect region, expand outward from the center of the defect region and assign an elastic modulus with gradient changes to the mesh; the elastic modulus value at the center of the defect region is 0, the elastic modulus value at the edge of the defect region is close to the elastic modulus value of the defect-free region, and the elastic modulus value at the center of the defect region increases in a gradient from the elastic modulus value at the edge of the defect region. Specifically, the gradient change of the elastic modulus value is distributed linearly from the center of the defect area to the edge. By replacing the tedious traditional method of targeted modeling of the defect area with the modulus gradient, time is saved and testing efficiency is improved.

[0025] Step 5: Calibrate the automotive part analysis model after elastic modulus allocation; The specific analysis model of the automotive parts after calibration of the elastic modulus assignment includes: A. Obtain the second modal frequency value of the automotive part analysis model after elastic modulus allocation; B. Calculate the relative error between the second modal frequency value and the measured modal frequency value; C. When the relative error is greater than or equal to the set second error value, adjust the elastic modulus distribution method until the error is less than the second error value.

[0026] The second error value is the acceptance standard for the defect simulation effect of the automotive part analysis model. Its strictness directly affects the reliability of the final durability analysis, ensuring that subsequent analysis steps can more accurately reflect the durability of the automotive part analysis model and the damage location prediction and the experimental results of the automotive parts. When the relative error is greater than or equal to the set second error value, it means that the elastic modulus allocation at this time has failed to accurately simulate the mechanical effect of the actual processing defect, and the elastic modulus allocation needs to be readjusted.

[0027] The methods for adjusting the elastic modulus include: adjusting the elastic modulus value assigned to each refined mesh and adjusting the change in elastic modulus value between each refined mesh.

[0028] By performing dual calibration of the automotive part analysis model in steps two and five, a solid data foundation was laid for subsequent durability performance analysis, ensuring a high degree of consistency between the subsequent simulation results and the failure behavior of the automotive parts.

[0029] Step 6: Perform durability performance simulation analysis on the automotive part analysis model after elastic modulus allocation.

[0030] In addition, this application also provides an analysis system for a method of performing durability performance simulation analysis on processing defects, including: The model building module is used to build an analysis model of the automotive parts to be analyzed. The attribute assignment module is used to refine the local mesh of the corresponding defect area in the automotive part analysis model. Based on the refined defect area, it expands outward from the center of the defect area and assigns an elastic modulus of gradient change to the mesh. Calibration module: Used to calibrate the automotive part analysis model before and after elastic modulus allocation, improving the reliability of subsequent analysis results; Test module: Used to perform durability performance simulation analysis on the automotive part analysis model after elastic modulus allocation, and output the results.

[0031] To facilitate understanding of the above technical solutions, this application provides embodiments for verification: The experimental object provided in this application is a license plate light bracket: Step 1: Establish an analysis model for the automotive parts to be analyzed; The experimental object provided in this application is a license plate light bracket, and a license plate light bracket model is built using Hyperworks. Step 2: Calibrate the automotive part analysis model through modal testing; The actual measured modal frequency of the license plate light bracket was 42.0Hz. After assembling the license plate light bracket and its connected vehicle frame, the first modal frequency of the license plate light bracket model obtained through modal analysis using finite element software was 36.4Hz, with a relative error greater than ≥5%. If the assembled model is not corrected, the final calculated durability performance of the bracket will differ significantly from the actual situation. Specifically, in the actual durability test, the license plate light bracket used in this study ultimately fractured at the bending point. Figure 2 As shown, if the license plate light bracket model is not calibrated and durability performance simulation is performed directly using a model with a calculated first modal frequency of 36.4Hz, the final analysis shows that the fracture location is not at the bending point. Figure 3 As shown, this does not accurately reflect the durability of the license plate light bracket; Therefore, based on the license plate light bracket model, this application adjusts the connection method between the license plate light bracket and the vehicle frame, changing the bolt hole connection from a simple rigid connection to a combination of rigidity and contact. The first modal frequency value of the calibrated license plate light bracket model is obtained again as 43.5Hz, which is closer to the measured modal frequency value. Therefore, the subsequent durability performance simulation evaluation of the license plate light bracket is based on the calibrated model.

[0032] Step 3: Identify the actual machining defect locations in the automotive part analysis model, and refine the local mesh in the corresponding defect area within the automotive part analysis model; The actual license plate light bracket produced has manufacturing defects such as bending cracks at the bending point. By measuring the location of the manufacturing defects, the grid size is refined on the corresponding license plate light bracket model. Figure 4 Based on the location of manufacturing defects in the license plate light bracket, the mesh is refined at the bends of the license plate light bracket model. A smaller mesh size is used to divide the bends of the license plate light bracket model, with the refined mesh size being no more than 1 / 2 of the original mesh size. Specifically, in this meshing process, the original mesh size at the bends and other parts of the bracket was 5mm, while the refined mesh size used for the bends was 2mm. Generally, a lower refined mesh size is better. Considering the impact on efficiency and accuracy, and taking into account the actual size of the manufacturing defects, it is recommended that the refined mesh size be 1 / 10 to 1 / 4 of the original mesh size.

[0033] Step 4: Based on the refined defect region, expand outward from the center of the defect region, and assign an elastic modulus with varying mesh gradient; like Figure 5As shown, grid 1, located at the center of the refined grid, represents the location where the crack caused by the processing defect occurs, and its elastic modulus value is 0. Grid 5, located far from the center of the refined grid, is considered to be a defect-free material since it has no processing defects. Therefore, according to the material properties of the steel used in the support, the elastic modulus value in the material properties of grid 5 is set to 210000. Grids 2-4, located in the refined grid area, are assigned elastic modulus values ​​of 52500, 105000, and 157500 respectively in a linearly increasing manner. It should be noted that, except for the change in elastic modulus, the material properties of meshes 1-5 are the same as those of the defect-free area of ​​the license plate light bracket model. Similarly, the material properties of the refined meshes in other directions are also assigned according to this method. Meshes with the same color in the figure have the same material properties.

[0034] Step 5: Calibrate the automotive part analysis model after elastic modulus allocation; from Figure 6 The comparison of modal frequency values ​​shows that after refining the mesh and redistributing the elastic modulus in the defect area, the second modal frequency value obtained by the license plate light bracket model is 41.7Hz. Compared with the first modal frequency value of 43.5Hz with no mesh refinement and the same elastic modulus, the second modal frequency value of 41.7Hz is closer to the actual measured modal frequency value of 42.0Hz of the license plate light bracket obtained by actual testing, so as to further improve the accuracy of subsequent durability simulation evaluation of the bracket. The second error value was set to 2%. The relative error between the obtained second modal frequency value of 41.7Hz and the actual measured modal frequency value of 42.0Hz of the license plate light bracket was 0.714%, which is less than the second error value of 2%. Therefore, it is shown that the elastic modulus value allocation in step four above is reasonable and no calibration is required.

[0035] Step Six: Perform durability performance simulation analysis on the automotive part analysis model after elastic modulus allocation; like Figure 7 As shown, the calibrated license plate light bracket model was subjected to durability simulation analysis, and the calculated damage value was 3.44E-8. The maximum damage value was also shown at the bending point of the bracket, which matched the fracture point of the bracket durability test.

[0036] If manufacturing defects are disregarded, and the license plate light bracket is modeled using conventional methods (i.e., without refining the mesh at the bends or assigning different elastic moduli), and all other conditions such as modeling and subsequent durability simulation analysis remain the same, the durability performance analysis is performed using the license plate light bracket model corrected in step two. The calculated durability performance results for the license plate light bracket are as follows: Figure 8 As shown, from Figure 8 As can be seen, the damage value at the bend of the license plate light bracket is 2.2E-12, which is much smaller than the damage value of 3.44E-8 calculated by this method. Moreover, the maximum damage value is not at the bend of the license plate light bracket, meaning that the first place where the license plate light bracket breaks is not at the bend.

[0037] Therefore, traditional modeling methods, which do not consider processing defects in modeling and durability assessment, may overestimate the durability performance and misjudge the location of the first fracture failure, thus affecting the final judgment result. In contrast, this method can better evaluate the durability performance and fracture failure location of parts with processing defects.

[0038] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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 between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0039] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0040] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for analyzing the durability performance of machining defects through simulation, characterized in that, Includes the following steps: An automotive part analysis model is established for the automotive parts to be analyzed, wherein different parts in the automotive part analysis model are constructed using different mesh formats; Based on the location of the machining defects in the automotive parts to be analyzed, local mesh refinement is performed on the corresponding defect areas in the automotive part analysis model; Based on the refined defect region, the mesh is expanded outward from the center of the defect region, and the elastic modulus is given a gradient change. The elastic modulus at the center of the defective region is 0, the elastic modulus at the edge of the defective region is close to the elastic modulus of the defect-free region, and the elastic modulus at the center of the defective region increases gradually from the edge. Durability simulation analysis was performed on the automotive part analysis model after the elastic modulus was allocated.

2. The method for analyzing the durability performance of machining defects according to claim 1, characterized in that, In the automotive part analysis model, the mesh size of the defective region is 1 / 10 to 1 / 4 of the mesh size of the defect-free region.

3. The method for analyzing the durability performance of machining defects according to claim 1, characterized in that, The gradient change of the elastic modulus value is distributed linearly from the center of the defect area to the edge in the automotive part analysis model.

4. The method for analyzing the durability performance of machining defects according to claim 1, characterized in that, In the automotive parts analysis model, different parts are constructed using different mesh formats, specifically including: Bolted connections can be rigid or in the form of a 1D mesh. Sheet metal parts or connectors are presented in a 2D mesh format; Castings or parts with complex structures are presented in 3D mesh form.

5. The method for analyzing the durability performance of machining defects according to claim 1, characterized in that, After establishing the analysis model of the automotive part to be analyzed, the process also includes calibrating the automotive part analysis model through modal testing. Specifically, the calibration of the automotive part analysis model through modal testing includes: Obtain the first modal frequency value of the automotive part analysis model and the measured modal frequency value of the automotive part to be analyzed; Calculate the relative error between the first modal frequency value and the measured modal frequency value; When the relative error is greater than or equal to the set first error value, adjust the automotive part analysis model until the error is less than the first error value.

6. The method for analyzing the durability performance of machining defects according to claim 5, characterized in that, The method of adjusting the automotive part analysis model when the relative error is greater than or equal to a set first error value includes adjusting the connection method between different parts in the automotive part analysis model, adjusting the mesh type of the connection area in the automotive part analysis model, and adjusting the model parameters of the connection area in the automotive part analysis model.

7. The method for analyzing the durability performance of machining defects according to claim 1, characterized in that, The refined defect region, starting from the center of the defect region and expanding outward, is given an elastic modulus with varying mesh gradients. It also includes an automotive part analysis model after calibrating the elastic modulus allocation.

8. The method for analyzing the durability performance of machining defects according to claim 7, characterized in that, The automotive part analysis model after calibration of elastic modulus allocation specifically includes: Obtain the second modal frequency value of the automotive part analysis model after elastic modulus allocation; Calculate the relative error between the second modal frequency value and the measured modal frequency value; When the relative error is greater than or equal to the set second error value, adjust the elastic modulus distribution method until the error is less than the second error value.

9. The method for analyzing the durability performance of machining defects according to claim 8, characterized in that, When the relative error is greater than or equal to the set second error value, the elastic modulus allocation method is adjusted until the error is less than the second error value. The elastic modulus adjustment method includes adjusting the elastic modulus value allocated to each refined mesh and the change value of the elastic modulus value between each refined mesh.

10. An analysis system based on the analysis method of claim 1, characterized in that, include: The model building module is used to build an analysis model of the automotive parts to be analyzed. The attribute assignment module is used to refine the local mesh of the corresponding defect area in the automotive part analysis model. Based on the refined defect area, it expands outward from the center of the defect area and assigns an elastic modulus of gradient change to the mesh. Test module: Used to perform durability performance simulation analysis on the automotive part analysis model after elastic modulus allocation, and output the results.

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