Casting fatigue damage determination method, device and equipment and storage medium

Abstract

The invention relates to a casting fatigue damage determination method and device, equipment and a storage medium, and relates to the technical field of computers. The method comprises the steps that the corresponding relation between the mechanical response and the fatigue life of each area of the casting is determined based on the tensile strength value of each area in multiple areas of the casting; and determining the fatigue damage of the casting based on the corresponding relation between the mechanical response and the fatigue life of each area. Therefore, the corresponding relation between the mechanical response and the fatigue life of the casting is determined in different areas, and the influence of non-uniform distribution of the material performance of the casting on the fatigue performance of the casting is considered, so that the influence of the fatigue performance of different areas of the casting on the fatigue performance of the casting is determined more accurately; therefore, the fatigue damage of the casting can be determined more accurately.

Description

Technical Field

[0001] The present application relates to the field of computer technology, in particular to the field of fatigue simulation technology, and specifically to a method, device, equipment and storage medium for determining fatigue damage of a casting. Background Art

[0002] With the increasing demand for lightweight automobiles, lightweight materials such as aluminum alloys are increasingly used in automobile parts. Cast aluminum alloys have the ability to produce parts with complex shapes and low processing costs. Therefore, they are increasingly used in automobiles. Complex structural parts such as engines, wheels, shock towers, and subframes are widely manufactured using cast aluminum alloys. In particular, the application of integrated die-casting technology makes cast aluminum alloys more important in automobile structures. In the fatigue resistance design process of cast aluminum alloys, in order to give full play to the potential of the material, the engineering generally adopts the safety life design method based on fatigue life curves and Miner's linear cumulative damage theory for fatigue simulation analysis. Therefore, the safe life design of cast aluminum alloys depends on accurate and reliable fatigue life curves.

[0003] In the traditional fatigue simulation process, the average fatigue life curve of the material is generally obtained through fatigue testing of the material. In the analysis process, the parts are assumed to be homogeneous materials, and the parts of the same material use the same fatigue life curve to calculate fatigue damage or fatigue life. However, due to the casting process, the differences in fluidity and cooling rate in different parts of the casting lead to great differences in the microstructure and defect distribution in different positions of the casting, which leads to great differences in the mechanical properties of different parts. Therefore, the traditional fatigue simulation method uses a fatigue life curve to analyze the fatigue performance of the entire casting, which is inaccurate. How to improve the accuracy of the fatigue performance analysis results of castings is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present application provides a method, device, equipment and storage medium for determining fatigue damage of castings, so as to at least solve the technical problem of low accuracy of fatigue performance analysis results of castings in the related art. The technical solution of the present application is as follows:

[0005] According to a first aspect of the present application, a method for determining fatigue damage of a casting is provided, the method comprising: determining the correspondence between the mechanical response and fatigue life of each region of the casting based on the tensile strength value of each region among multiple regions of the casting; and determining the fatigue damage of the casting based on the correspondence between the mechanical response and fatigue life of each region.

[0006] According to the above technical means, the casting is divided into multiple regions, and the corresponding relationship between the mechanical response and fatigue life of each region is determined based on the tensile strength value of each region, taking into account the influence of the uneven distribution of the material properties of the casting on the fatigue performance of the casting, so as to more accurately determine the influence of the fatigue performance of different regions of the casting on the fatigue performance of the casting, thereby more accurately determining the fatigue damage of the casting, and improving the reliability and accuracy of determining the fatigue damage of the casting. In addition, based on the corresponding relationship between the mechanical response and fatigue life of each region, different regions of the casting can be designed more reasonably to improve the fatigue durability performance of the key regions of the casting.

[0007] In a possible implementation, the method further includes: dividing the casting into a plurality of regions based on tensile strength distribution data of the casting; the tensile strength distribution data is used to characterize the distribution of the maximum tensile stress that the casting can withstand when subjected to a tensile force.

[0008] According to the above technical means, based on the tensile strength distribution data of the casting, the mechanical properties of different areas of the casting can be evaluated more accurately, and the casting can be divided into multiple areas so that different areas of the casting correspond to different mechanical properties, so that for multiple areas, the fatigue performance of each area can be determined separately, so as to more accurately predict the fatigue life of the casting and improve the accuracy of determining the fatigue damage of the casting.

[0009] In another possible implementation, the tensile strength distribution data includes: the tensile strength value of each unit in the finite element model of the casting; based on the tensile strength distribution data of the casting, the casting is divided into multiple regions, including: based on the tensile strength value of each unit in the finite element model of the casting, determining multiple tensile strength value ranges; based on the multiple tensile strength value ranges, dividing the regions in the finite element model of the casting that belong to the same tensile strength value range into one region, thereby obtaining multiple regions.

[0010] According to the above technical means, based on the tensile strength values ​​of different regions of the casting, the tensile strength ranges of multiple regions are determined, so that the finite element model of the casting is divided into regions based on the tensile strength values ​​to obtain multiple regions of the casting, so that different regions of the casting correspond to different fatigue properties, so as to perform regional analysis on the casting, determine the fatigue properties of different regions, and achieve accurate fatigue analysis of the casting, so as to apply it to the anti-fatigue design of the casting and improve the anti-fatigue performance of the casting.

[0011] In another possible implementation, the method further includes: performing mechanical testing on a tensile test specimen of the raw material of the casting to obtain material property parameters of the raw material of the casting; and determining tensile strength distribution data of the casting based on the material property parameters.

[0012] According to the above technical means, the actual performance parameters of the material of the casting are obtained through sample testing, so as to more accurately determine the mechanical property data of the casting, thereby determining the tensile strength distribution data of the casting, thereby improving the accuracy of the tensile strength distribution data of the casting, so as to reasonably divide the casting into regions based on the accurate tensile strength distribution data, thereby improving the accuracy of determining the fatigue damage of the casting.

[0013] In another possible implementation, the material performance parameters include: the material tensile strength of the casting; based on the material performance parameters, determining the tensile strength distribution data of the casting, including: simulating the die-casting process of the casting to obtain the die-casting process simulation results of the casting; based on the material tensile strength and the die-casting process simulation results, determining the tensile strength distribution of the casting; mapping the tensile strength distribution to the finite element model of the casting to obtain the tensile strength distribution data of the casting.

[0014] According to the above technical means, through the process simulation results of castings, the microstructural differences in different areas of the castings can be more accurately understood to determine the mechanical properties of different areas, so as to more accurately determine the tensile strength distribution data of the castings, so as to divide the castings into regions based on the tensile strength distribution data and improve the accuracy of determining fatigue damage of castings.

[0015] In another possible embodiment, the above method also includes: sampling the target position of the casting and measuring the actual tensile strength of the target position; determining the simulated tensile strength of the target position based on the tensile strength distribution data of the casting; when the difference between the actual tensile strength and the simulated tensile strength at the target position is greater than a preset threshold, adjusting the process simulation parameters of the casting and re-simulating the die-casting process of the casting.

[0016] According to the above technical means, by comparing the actual tensile strength of the casting with the simulated tensile strength, the deviation of the simulation model of the casting can be discovered and corrected, the process simulation parameters of the casting can be adjusted according to the actual tensile strength results, the simulation process of the die-casting process of the casting can be optimized, and the accuracy of the die-casting process simulation of the casting can be improved.

[0017] In another possible embodiment, the material performance parameters include: an initial fatigue life parameter; based on the tensile strength value of each region of the casting, determining the corresponding relationship between the mechanical response and the fatigue life of each region of the casting, including: for each region of the multiple regions, based on the tensile strength value of each region, correcting the initial fatigue life parameter to obtain the fatigue life parameter corresponding to each region; based on the fatigue life parameter corresponding to each region, determining the corresponding relationship between the mechanical response and the fatigue life of each region.

[0018] According to the above technical means, the initial fatigue life parameters are corrected based on the tensile strength values ​​of different regions to determine the correspondence between the mechanical response and fatigue life of each region, thereby realizing customized fatigue life evaluation of different regions of the casting, taking into account the performance differences in different regions of the casting, and improving the accuracy of fatigue performance analysis of the casting.

[0019] In another possible implementation, the mechanical response includes: stress and strain; the fatigue life parameters include: stress-life fatigue strength coefficient, strain-life fatigue strength coefficient and cyclic strength coefficient.

[0020] According to the above technical means, the stress-life correspondence and strain-life correspondence correspond to different fatigue analysis methods, and the corresponding fatigue life parameters are selected according to the actual mechanical response to more accurately predict the fatigue life of the casting. In addition, different materials may exhibit different fatigue behaviors under stress or strain control. Distinguishing the fatigue life parameters of stress and strain helps to adapt to the characteristics of different materials of castings.

[0021] In another possible implementation, the fatigue damage of the casting is determined based on the fatigue life curve of each region, including: determining the mechanical response of the casting under simulation conditions based on a finite element model of the casting; calculating the fatigue damage of each region under simulation conditions based on the mechanical response of the casting under simulation conditions according to the correspondence between the mechanical response and fatigue life of each region; determining the fatigue damage of the casting based on the fatigue damage of each region under simulation conditions.

[0022] According to the above technical means, accurate fatigue damage assessment can be provided for each area of ​​the casting, which helps to identify potential risk areas of the casting. In addition, the fatigue damage data of the casting can be applied to the anti-fatigue design of the casting to improve the anti-fatigue performance of the casting.

[0023] According to a second aspect provided by the present application, a casting fatigue damage determination device is provided, the device comprising: a determination module. The determination module is used to determine the corresponding relationship between the mechanical response and the fatigue life of each region of the casting based on the tensile strength value of each region among multiple regions of the casting; the determination module is also used to determine the fatigue damage of the casting based on the corresponding relationship between the mechanical response and the fatigue life of each region.

[0024] In a possible implementation, the device further includes: a division module. The division module is used to divide the casting into multiple regions based on the tensile strength distribution data of the casting; the tensile strength distribution data is used to characterize the distribution of the maximum tensile stress that the casting can withstand when subjected to a tensile force.

[0025] In another possible implementation, the tensile strength distribution data includes: the tensile strength value of each unit in the finite element model of the casting; a partitioning module, specifically used to determine multiple tensile strength value ranges based on the tensile strength value of each unit in the finite element model of the casting; based on the multiple tensile strength value ranges, dividing the area in the finite element model of the casting that belongs to the same tensile strength value range into one area, thereby obtaining multiple areas.

[0026] In another possible embodiment, the device further includes: a testing module, which is used to perform mechanical testing on a tensile specimen of a raw material of the casting to obtain material performance parameters of the raw material of the casting; and a determination module, which is further used to determine tensile strength distribution data of the casting based on the material performance parameters.

[0027] In another possible embodiment, the material performance parameters include: the tensile strength of the material of the casting; a determination module, specifically used to simulate the die-casting process of the casting to obtain the die-casting process simulation results of the casting; based on the material tensile strength and the die-casting process simulation results, determining the tensile strength distribution of the casting; mapping the tensile strength distribution to the finite element model of the casting to obtain the tensile strength distribution data of the casting.

[0028] In another possible embodiment, the device further includes: a measuring module and an adjusting module. The measuring module is used to sample the target position of the casting and measure the actual tensile strength of the target position; the determining module is also used to determine the simulated tensile strength of the target position based on the tensile strength distribution data of the casting; the adjusting module is used to adjust the process simulation parameters of the casting and re-simulate the die-casting process of the casting when the difference between the actual tensile strength and the simulated tensile strength of the target position is greater than a preset threshold.

[0029] In another possible implementation, the material performance parameters include: an initial fatigue life parameter; a determination module, specifically used to correct the initial fatigue life parameter for each of the multiple regions based on the tensile strength value of each region to obtain the fatigue life parameter corresponding to each region; based on the fatigue life parameter corresponding to each region, determine the correspondence between the mechanical response and fatigue life of each region.

[0030] In another possible implementation, the mechanical response includes: stress and strain; the fatigue life parameters include: stress-life fatigue strength coefficient, strain-life fatigue strength coefficient and cyclic strength coefficient.

[0031] In another possible implementation, the determination module is specifically used to determine the mechanical response of the casting under simulation conditions based on the finite element model of the casting; based on the mechanical response of the casting under simulation conditions, calculate the fatigue damage of each region under simulation conditions according to the correspondence between the mechanical response and fatigue life of each region; based on the fatigue damage of each region under simulation conditions, determine the fatigue damage of the casting.

[0032] According to the third aspect provided by the present application, an electronic device is provided, comprising: a processor; a memory for storing processor executable instructions; wherein the processor is configured to execute instructions to implement the method of the above-mentioned first aspect and any possible implementation manner thereof.

[0033] According to the fourth aspect provided by the present application, a computer-readable storage medium is provided. When the instructions in the computer-readable storage medium are executed by a processor of an electronic device, the electronic device is enabled to execute the method in the above-mentioned first aspect and any possible implementation method thereof.

[0034] According to the fifth aspect provided by the present application, a computer program product is provided, the computer program product comprising computer instructions, and when the computer instructions are executed on an electronic device, the electronic device executes the method of the above-mentioned first aspect and any possible implementation manner thereof.

[0035] Therefore, the above technical features of the present application have the following beneficial effects:

[0036] (1) The casting is divided into multiple regions, and based on the tensile strength value of each region, the corresponding relationship between the mechanical response and fatigue life of each region is determined respectively, taking into account the influence of the uneven distribution of the material properties of the casting on the fatigue performance of the casting, so as to more accurately determine the influence of the fatigue performance of different regions of the casting on the fatigue performance of the casting, thereby more accurately determining the fatigue damage of the casting, and improving the reliability and accuracy of determining the fatigue damage of the casting. In addition, based on the corresponding relationship between the mechanical response and fatigue life of each region, different regions of the casting can be designed more reasonably to improve the fatigue durability performance of the key regions of the casting.

[0037] (2) Based on the tensile strength distribution data of the casting, the mechanical properties of different areas of the casting can be evaluated more accurately. The casting can be divided into multiple areas so that different areas of the casting correspond to different mechanical properties. In order to determine the fatigue performance of each area separately for multiple areas, the fatigue life of the casting can be predicted more accurately, thereby improving the accuracy of determining the fatigue damage of the casting.

[0038] (3) Based on the tensile strength values ​​of different regions of the casting, the tensile strength ranges of multiple regions are determined, and the finite element model of the casting is divided based on the tensile strength values ​​to obtain multiple regions of the casting, so that different regions of the casting correspond to different fatigue properties, so that the casting can be analyzed in different regions, the fatigue properties of different regions can be determined, and accurate fatigue analysis of the casting can be achieved, so as to be applied to the anti-fatigue design of the casting and improve the anti-fatigue performance of the casting.

[0039] (4) Through sample testing, the actual performance parameters of the casting material are obtained so as to more accurately determine the mechanical properties data of the casting, thereby determining the tensile strength distribution data of the casting, thereby improving the accuracy of the tensile strength distribution data of the casting, so as to reasonably divide the casting into different areas based on the accurate tensile strength distribution data, thereby improving the accuracy of determining the fatigue damage of the casting.

[0040] (5) Through the process simulation results of castings, we can more accurately understand the microstructural differences in different areas of the castings, determine the mechanical properties of different areas, and more accurately determine the tensile strength distribution data of the castings, so as to divide the castings into regions based on the tensile strength distribution data and improve the accuracy of determining the fatigue damage of the castings.

[0041] (6) By comparing the actual tensile strength of the casting with the simulated tensile strength, the deviation of the simulation model of the casting can be discovered and corrected, and the process simulation parameters of the casting can be adjusted according to the actual tensile strength results, so as to optimize the simulation process of the die-casting process of the casting and improve the accuracy of the die-casting process simulation of the casting.

[0042] (7) Based on the tensile strength values ​​of different regions, the initial fatigue life parameters are modified to determine the corresponding relationship between the mechanical response and fatigue life of each region, thereby realizing customized fatigue life evaluation of different regions of the casting, taking into account the performance differences of different regions of the casting, and improving the accuracy of fatigue performance analysis of the casting.

[0043] (8) The stress-life correspondence and strain-life correspondence correspond to different fatigue analysis methods. The corresponding fatigue life parameters are selected according to the actual mechanical response to more accurately predict the fatigue life of the casting. In addition, different materials may exhibit different fatigue behaviors under stress or strain control. Distinguishing the fatigue life parameters of stress and strain helps to adapt to the characteristics of different materials of castings.

[0044] (9) It can provide accurate fatigue damage assessment for each area of ​​the casting, which helps to identify potential risk areas of the casting. In addition, the fatigue damage data of the casting can be applied to the anti-fatigue design of the casting to improve the anti-fatigue performance of the casting.

[0045] It should be noted that the technical effects brought about by any implementation method in the second to fifth aspects can refer to the technical effects brought about by the corresponding implementation method in the first aspect, and will not be repeated here.

[0046] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application, and do not constitute an improper limitation on the present application.

[0048] Figure 1 is a flow chart showing a method for determining fatigue damage of a casting according to an exemplary embodiment;

[0049] Figure 2 is a flow chart showing another method for determining fatigue damage of a casting according to an exemplary embodiment;

[0050] Figure 3 is a flow chart showing another method for determining fatigue damage of a casting according to an exemplary embodiment;

[0051] Figure 4 is a schematic diagram showing a plurality of regions of a casting according to an exemplary embodiment;

[0052] Figure 5 is a flow chart showing another method for determining fatigue damage of a casting according to an exemplary embodiment;

[0053] Figure 6 is a cyclic stress-strain curve diagram of a base material of a casting according to an exemplary embodiment;

[0054] Figure 7 is an EN curve diagram of a base material of a casting according to an exemplary embodiment;

[0055] Figure 8 is a flow chart showing another method for determining fatigue damage of a casting according to an exemplary embodiment;

[0056] Fig. 9 is a schematic diagram of tensile strength distribution of a casting process simulation result according to an exemplary embodiment;

[0057] Fig.10 is a schematic diagram of tensile strength distribution of a finite element model of a casting according to an exemplary embodiment;

[0058] Fig.11is a flow chart showing another method for determining fatigue damage of a casting according to an exemplary embodiment;

[0059] Fig.12 is a schematic diagram showing a comparison between the actual tensile strength and the simulated tensile strength of a casting according to an exemplary embodiment;

[0060] Fig.13 is a flow chart showing another method for determining fatigue damage of a casting according to an exemplary embodiment;

[0061] Fig.14 is a cyclic stress-strain curve diagram of each region of a casting according to an exemplary embodiment;

[0062] Fig.15 is an EN curve diagram of each region of a casting according to an exemplary embodiment;

[0063] Fig.16 is a flow chart showing another method for determining fatigue damage of a casting according to an exemplary embodiment;

[0064] Fig.17 is a flow chart showing another method for determining fatigue damage of a casting according to an exemplary embodiment;

[0065] Fig.18 is a block diagram of a casting fatigue damage determination device according to an exemplary embodiment;

[0066] Fig.19 It is a block diagram of an electronic device according to an exemplary embodiment. DETAILED DESCRIPTION

[0067] In order to enable ordinary persons in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0068] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0069] With the increasing demand for lightweight automobiles, lightweight materials such as aluminum alloys are increasingly used in automobile parts. As cast aluminum alloys have the ability to produce parts with complex shapes and low processing costs, they are increasingly used in automobiles. Complex structural parts such as engines, wheels, shock towers, and subframes are widely manufactured using cast aluminum alloys. In particular, the application of integrated die-casting technology makes cast aluminum alloys more important in automobile structures. In the fatigue design process of cast aluminum alloy structures, in order to give full play to the potential of materials, the engineering generally adopts the safety life design method based on fatigue life curves (stress-life (SN) curves or strain-life (EN) curves) and Miner's linear cumulative damage theory for fatigue simulation analysis. Therefore, the safety life design method of castings relies on accurate and reliable fatigue life curves. In the traditional fatigue simulation process, the average fatigue life curve of the material is generally obtained through fatigue testing of the material. In the analysis process, the parts are assumed to be homogeneous materials, and the parts of the same material use the same fatigue life curve to calculate fatigue damage or fatigue life.

[0070] Due to the casting process, the differences in fluidity and cooling rate in different parts of the casting lead to great differences in the microstructure and defect distribution of different parts of the casting, which in turn leads to great differences in the mechanical properties of different parts. Taking tensile strength as an example, the tensile strength of the integrated die-cast rear floor of the car far away from the pouring gate is 15%-20% lower than the tensile strength measured near the pouring gate. For the same type of material, it can be inferred from engineering experience that a decrease in tensile strength indicates a decrease in fatigue performance. Therefore, for castings, it is not accurate to use a fatigue life curve to characterize the fatigue performance of the entire aluminum casting as in the traditional fatigue simulation method. The actual fatigue performance of the low-performance parts of the casting is likely to be much lower than the fatigue life curve used.

[0071] On the other hand, the fatigue life curve of castings needs to be determined through a large number of material fatigue tests, which has a long test cycle and high test cost. For castings, due to the complex geometric shape, many positions cannot be sampled for testing in large quantities. Therefore, the fatigue performance distribution of actual castings cannot be completely obtained through experimental testing. Simulation can generally only obtain the fatigue performance parameters of the basic material obtained using a flat mold or a test rod mold. Compared with flat molds and test rod molds, the geometry of the die-casting molds of actual parts is more complex and larger in size. The fluidity of the molten metal in the die-casting mold of the parts is also worse, and the difference in cooling rate is also greater. Therefore, there is a significant difference between the fatigue performance of the basic material and the performance of the actual parts. The fatigue life characteristics of the parts obtained by the durability simulation analysis using the fatigue performance parameters of the basic material are quite different from the actual situation of the parts. The simulation analysis cannot avoid design deficiencies and redundancies in advance. Therefore, how to improve the accuracy of the fatigue performance analysis results of castings is a technical problem that needs to be solved urgently.

[0072] In view of the above problems, the present application proposes a method for determining fatigue damage of castings, in which the castings are divided into multiple regions, and the corresponding relationship between the mechanical response and fatigue life of each region is determined based on the tensile strength value of each region, taking into account the influence of the uneven distribution of the material properties of the castings on the fatigue performance of the castings, so as to more accurately determine the influence of the fatigue performance of different regions of the castings on the fatigue performance of the castings, thereby more accurately determining the fatigue damage of the castings, and improving the reliability and accuracy of determining the fatigue damage of the castings. In addition, based on the corresponding relationship between the mechanical response and fatigue life of each region, different regions of the castings can be designed more reasonably to improve the fatigue durability performance of the key regions of the castings.

[0073] For ease of understanding, the method for determining fatigue damage of castings provided in the present application is specifically introduced below with reference to the accompanying drawings.

[0074] Figure 1 is a flow chart of a method for determining fatigue damage of a casting according to an exemplary embodiment. Figure 1 As shown, the casting fatigue damage determination method comprises the following steps:

[0075] S101. Determine a corresponding relationship between a mechanical response and a fatigue life of each region of the casting based on a tensile strength value of each region of the casting.

[0076] As a possible implementation method, the determination device can determine the correspondence between the mechanical response and fatigue life of each of the multiple regions of the casting based on the tensile strength value of each region of the multiple regions of the casting, so as to perform fatigue analysis on different regions of the casting based on the correspondence between the mechanical response and fatigue life of each region to determine the fatigue damage in different regions.

[0077] Exemplarily, the determination device can determine the tensile strength value corresponding to each region of the multiple regions of the casting, and then correct the initial fatigue life parameters corresponding to the material of the region based on the tensile strength value of the region to determine the fatigue life parameters corresponding to the region, and then correct the correspondence between the mechanical response and fatigue life of the material of the casting based on the fatigue life parameters corresponding to each region to obtain the correspondence between the mechanical response and fatigue life of each region.

[0078] S102. Determine fatigue damage of the casting based on the corresponding relationship between the mechanical response and fatigue life of each region.

[0079] As a possible implementation method, after the determination device determines the correspondence between the mechanical response and fatigue life of each of the multiple regions of the casting, the fatigue damage of the casting can be determined based on the correspondence between the mechanical response and fatigue life of each region.

[0080] Exemplarily, the determination device can determine the mechanical response of the casting under the simulation conditions based on the finite element model of the casting, thereby determining the mechanical response of each region of the casting, and calculating the fatigue damage of each unit in each region under the simulation conditions according to the correspondence between the mechanical response and fatigue life of each region, thereby determining the fatigue damage of the casting based on the fatigue damage of each unit in each region.

[0081] It should be understood that the determination device divides the casting into multiple regions, and thus determines the corresponding relationship between the mechanical response and fatigue life of each region based on the tensile strength value of each region, taking into account the influence of the uneven distribution of the material properties of the casting on the fatigue performance of the casting, so as to more accurately determine the influence of the fatigue performance of different regions of the casting on the fatigue performance of the casting, and the determination device can more accurately determine the fatigue damage of the casting, thereby improving the reliability and accuracy of determining the fatigue damage of the casting. In addition, the determination device can also design different regions of the casting more reasonably based on the corresponding relationship between the mechanical response and fatigue life of each region, so as to improve the fatigue durability performance of the key regions of the casting.

[0082] In some embodiments, before determining the correspondence between the mechanical response and fatigue life of each region of the casting, the determining device may further divide the casting into a plurality of regions based on the tensile strength distribution data of the casting. Figure 2 As shown, the casting fatigue damage determination method provided in the embodiment of the present application further includes the following steps S100:

[0083] S100. Divide the casting into a plurality of regions based on the tensile strength distribution data of the casting.

[0084] Among them, the tensile strength distribution data is used to characterize the distribution of the maximum tensile stress that the casting can withstand when subjected to tensile force.

[0085] As a possible implementation manner, the determination device may obtain tensile strength distribution data of the casting, and thereby divide the casting into a plurality of regions based on the tensile strength distribution data of the casting.

[0086] Exemplarily, the determination device can determine the tensile strength value of each unit in the finite element model of the casting based on the finite element model of the casting, thereby determining multiple tensile strength value ranges based on the tensile strength value of each unit in the finite element model of the casting, and dividing the areas in the finite element model of the casting that belong to the same tensile strength value range into one area, thereby obtaining multiple areas of the casting.

[0087] It should be understood that the determination device can more accurately evaluate the mechanical properties of different regions of the casting based on the tensile strength distribution data of the casting, divide the casting into multiple regions, so that different regions of the casting correspond to different mechanical properties, so as to determine the fatigue performance of each region separately for multiple regions, more accurately predict the fatigue life of the casting, and improve the accuracy of determining fatigue damage of the casting.

[0088] In other embodiments, the tensile strength distribution data includes: the tensile strength value of each unit in the finite element model of the casting. The determining device can divide the casting into multiple regions based on the tensile strength value of each unit in the finite element model of the casting. Figure 3 As shown, the above step S100 can be specifically implemented as the following steps S1001-S1002:

[0089] S1001. Determine multiple tensile strength value ranges based on the tensile strength value of each unit in the finite element model of the casting.

[0090] As a possible implementation, the determining device may determine a plurality of tensile strength value ranges based on the tensile strength value of each unit in the finite element model of the casting, so as to divide the casting into regions based on the plurality of tensile strength ranges to obtain a plurality of regions.

[0091] Exemplarily, the determining device may set the tensile strength difference value S between different regions based on the tensile strength value of each unit in the finite element model of the casting. △ According to the tensile strength distribution data of the casting, the maximum tensile strength value in the finite element model of the casting is calculated. and minimum tensile strength And calculate the regional boundary value Wherein, i=1, 2, ···, n-1, n is the number of regions that the casting needs to be divided into, and n is greater than The minimum integer of Multiple tensile strength value ranges are obtained.

[0092] As an example, the casting is an integrated die-cast rear floor, and the tensile strength difference value S between different regions of the casting is set △ The tensile strength distribution data shows that the maximum tensile strength of the casting on the finite element model is 266.54MPa, and the minimum tensile strength is 90.96MPa. Therefore, the critical tensile strength values ​​for regional division are calculated to be 247MPa, 227MPa, 207MPa, 187MPa, 167MPa, 147MPa, 127MPa, 107MPa, and 91MPa, respectively, and 9 tensile strength value ranges are obtained.

[0093] S1002. Based on multiple tensile strength value ranges, divide the regions in the finite element model of the casting that belong to the same tensile strength value range into one region to obtain multiple regions.

[0094] As a possible implementation manner, after the determination device determines multiple tensile strength value ranges, the region in the finite element model of the casting belonging to the same tensile strength value range can be divided into one region based on the multiple tensile strength value ranges to obtain multiple regions.

[0095] Exemplarily, the determining device may compare the tensile strength value of each unit in the finite element model of the casting with a plurality of tensile strength value ranges, and if the tensile strength value of the unit in the finite element model of the casting is greater than or equal to Less than or equal to The units of the finite element model of the casting are classified into region i, and the region division of the casting is completed to obtain multiple regions. Among them, the tensile strength value of each region is expressed by the lower limit of the tensile strength of the region, that is, the tensile strength of region i is

[0096] As an example, the determination device uses the above critical value to divide the integrated die-cast floor into regions, and after the division, the area with a tensile strength value lower than 187 MPa is less than 1% of the total area. This part of the area has little effect on the fatigue analysis results of the integrated die-cast floor. Therefore, in this embodiment, the area with a tensile strength lower than 187 MPa is included in the 187 MPa area. Figure 4 is a schematic diagram of dividing multiple regions of a casting according to an exemplary embodiment, such as Figure 4 As shown, different colors represent different areas. After the integrated die-casting, the floor is divided into four areas 401, 402, 403 and 404. 401 represents area 1 with a tensile strength of 247Mpa, 402 represents area 2 with a tensile strength of 227Mpa, 403 represents area 3 with a tensile strength of 207Mpa, and 404 represents area 4 with a tensile strength of 187Mpa.

[0097] It should be understood that the determination device determines the tensile strength range of multiple regions based on the tensile strength values ​​of different regions of the casting, and thus divides the finite element model of the casting based on the tensile strength values ​​to obtain multiple regions of the casting, so that different regions of the casting correspond to different fatigue properties, so as to perform regional analysis on the casting, determine the fatigue properties of different regions, and achieve accurate fatigue analysis of the casting, so as to apply it to the anti-fatigue design of the casting and improve the anti-fatigue performance of the casting.

[0098] In some other embodiments, the determining device can also determine the tensile strength distribution data of the casting by performing mechanical testing on tensile specimens of the raw materials of the casting. Figure 5 As shown, the casting fatigue damage determination method provided in the embodiment of the present application further includes the following steps S501-S502:

[0099] S501. Perform mechanical testing on a tensile test specimen of a raw material of the casting to obtain material performance parameters of the raw material of the casting.

[0100] The tensile test specimen of the raw material of the casting refers to a standard tensile test specimen obtained by die casting using a flat die and / or a test bar die.

[0101] As a possible implementation manner, the determination device may perform mechanical testing on a standard tensile specimen obtained by a flat die and / or a test bar die to obtain material property parameters of the raw material of the casting.

[0102] For example, the material performance parameters are used to reflect the mechanical properties of the material of the casting, and the determination device can use a standard tensile specimen obtained by a flat mold or a test rod mold to perform a mechanical test to obtain the material performance parameters. The material performance parameters that the determination device needs to obtain should include the tensile strength σ u, and the fatigue life parameters of the fatigue life curve (i.e., the corresponding relationship between mechanical response and fatigue life) used for fatigue simulation calculation. When the fatigue life curve is an SN curve, the fatigue life parameters that need to be obtained by the determination device include the fatigue strength coefficient σ of the SN curve f and fatigue strength index b 1 , the expression of SN curve is shown in expression (1):

[0103]

[0104] Among them, σ α It represents the stress level of the casting, and N represents the life of the casting, that is, the number of loading cycles, which is a positive integer greater than 0.

[0105] When the fatigue life curve is an EN curve, the fatigue life parameters that need to be obtained by the determination device include the fatigue strength coefficient σ′ of the EN curve f , fatigue strength index b, fatigue ductility coefficient ε′ f , fatigue ductility index c, and cyclic strength coefficient K′ and cyclic strain hardening index n′ of cyclic stress-plastic strain curve. The fatigue life curve formula and the expression of cyclic stress-plastic strain curve are shown in expressions (2) and (3):

[0106]

[0107] σ α =K′(ε pa ) n′ (3);

[0108] Among them, ε α represents the overall strain of the casting, ε pa represents plastic strain, and E represents the elastic modulus of the material of the casting.

[0109] It should be understood that the above parameter σ u , σ f 、b 1 , ε′ f , b, ε′ f , c, K′, n′ are obtained by material testing according to corresponding test standards.

[0110] As an example, the integrated die-cast rear floor is produced using heat-treatment-free aluminum alloy material. The tensile strength of the base material of the integrated die-cast rear floor is u It is 275MPa. Figure 6 is a cyclic stress-strain curve diagram of a base material of a casting according to an exemplary embodiment, Figure 7is an EN curve diagram of a base material of a casting according to an exemplary embodiment. The cyclic stress-strain curve and EN curve required for fatigue analysis of the integrated die-casting floor are as follows Figure 6 and Figure 7 As shown, the cyclic stress-strain, the ordinate is the stress amplitude, the unit is MPa, the value range is 0-300, the abscissa is the strain amplitude, the unit is uE, the value range is 0-1.2E4, the change trend of cyclic stress-strain is shown in Figure 6 Strain life, the vertical axis is strain amplitude, the unit is uE, the value range is 1000-1E5, the horizontal axis is life, the unit is the number of cycles, the value range is 1-1E10, the change trend of strain life is shown in Figure 7 shown.

[0111] S502. Determine the tensile strength distribution data of the casting based on the material performance parameters.

[0112] As a possible implementation manner, after the determination device determines the material property parameters of the raw material of the casting, the tensile strength distribution data of the casting can be determined based on the material property parameters.

[0113] Exemplarily, the determination device can simulate the die-casting process of the casting to obtain the die-casting process simulation results of the casting, thereby determining the tensile strength distribution of the casting based on the tensile strength of the material and the die-casting process simulation results, and mapping the tensile strength distribution to the finite element model of the casting to obtain the tensile strength distribution data of the casting.

[0114] It should be understood that the determination device obtains the actual performance parameters of the material of the casting through sample testing so as to more accurately determine the mechanical property data of the casting, thereby determining the tensile strength distribution data of the casting, thereby improving the accuracy of the tensile strength distribution data of the casting, so as to reasonably divide the casting into regions based on the accurate tensile strength distribution data, thereby improving the accuracy of determining the fatigue damage of the casting.

[0115] In some other embodiments, the material performance parameter includes: the tensile strength of the material of the casting. The determining device can determine the tensile strength distribution data of the casting based on the tensile strength of the material of the casting. Figure 8 As shown, the above step S502 can be specifically implemented as the following steps S5021-S5023:

[0116] S5021. Simulate the die-casting process of the casting to obtain the die-casting process simulation result of the casting.

[0117] As a possible implementation manner, the determination device may simulate the die-casting process of the casting to obtain a simulation result of the die-casting process of the casting.

[0118] Exemplarily, the die-casting process simulation of castings is to simulate the physical phenomena in the casting process. The determination device can establish a three-dimensional geometric model of the casting and the die-casting mold, mesh the three-dimensional geometric model of the casting and the die-casting mold, generate a computational grid for simulation, and define the material properties of the computational grid, such as the viscosity, thermal conductivity, specific heat capacity and solidification temperature of the melt, set the boundary conditions (such as temperature, pressure) and initial conditions (such as the initial temperature of the mold and the melt) of the simulation, input the die-casting process parameters, such as filling speed, pressure, cooling rate and holding time, run the simulation software, perform numerical calculations, simulate the filling, cooling and solidification process of the metal melt, and obtain the die-casting process simulation results of the casting.

[0119] S5022. Determine the tensile strength distribution of the casting based on the tensile strength of the material and the die-casting process simulation results.

[0120] As a possible implementation manner, after the determination device obtains the die-casting process simulation result of the casting, the tensile strength distribution of the casting can be determined based on the material tensile strength and the die-casting process simulation result.

[0121] Exemplarily, the determination device can extract the mechanical property prediction, stress distribution and potential defect information of the casting based on the simulation results of the casting die-casting process, thereby obtaining the tensile strength distribution of the casting based on the material tensile strength of the casting and the mechanical properties and stress distribution of different regions of the casting.

[0122] As an example, Fig. 9 is a schematic diagram of tensile strength distribution of a casting process simulation result according to an exemplary embodiment. Fig. 9 As shown in the figure, the tensile strength distribution of the casting process simulation results gradually decreases from deep to shallow.

[0123] S5023. Map the tensile strength distribution to the finite element model of the casting to obtain the tensile strength distribution data of the casting.

[0124] As a possible implementation manner, after the determination device determines the tensile strength distribution of the casting, the tensile strength distribution can be mapped to the finite element model of the casting to obtain the tensile strength distribution data of the casting.

[0125] Exemplarily, the determination device can perform finite element modeling on the casting, obtain unit information and node coordinates of the finite element model of the casting, map the tensile strength distribution of the process simulation results of the casting to the units of the finite element model of the casting, and obtain the tensile strength value of each unit in the finite element model of the casting, that is, the tensile strength distribution data of the finite element model of the casting.

[0126] As an example, Fig.10 is a schematic diagram of tensile strength distribution of a finite element model of a casting according to an exemplary embodiment. Fig.10 As shown in the figure, the tensile strength distribution of the finite element model of the casting decreases gradually from deep to shallow.

[0127] It should be understood that the determination device uses the process simulation results of the casting to more accurately understand the microstructural differences in different areas of the casting to determine the mechanical properties of different areas, thereby more accurately determining the tensile strength distribution data of the casting, so as to divide the casting into regions based on the tensile strength distribution data and improve the accuracy of determining fatigue damage of the casting.

[0128] In some other embodiments, the determination device may also measure the actual tensile strength of the casting, and compare the actual tensile strength with the simulated tensile strength. If the difference between the actual tensile strength and the simulated tensile strength is large, the process simulation parameters of the casting are adjusted, and the die-casting process of the casting is re-simulated to improve the accuracy of the simulated tensile strength of the casting. Fig.11 As shown, the casting fatigue damage determination method provided in the embodiment of the present application further includes the following steps S1101-S1103:

[0129] S1101. Sample the target position of the casting and measure the actual tensile strength of the target position.

[0130] As a possible implementation manner, the determination device may select multiple target positions of the casting for sampling, and measure the actual tensile strength of the samples at the target positions.

[0131] S1102. Determine the simulated tensile strength of the target position based on the tensile strength distribution data of the casting.

[0132] As a possible implementation manner, the determination device may also determine the simulated tensile strength on the finite element model of the casting corresponding to the multiple target positions based on the tensile strength distribution data of the casting.

[0133] S1103. When the difference between the actual tensile strength at the target position and the simulated tensile strength is greater than a preset threshold, adjust the process simulation parameters of the casting and re-simulate the die-casting process of the casting.

[0134] As a possible implementation method, after determining that the device obtains the actual tensile strength and simulated tensile strength of multiple target positions, the actual tensile strength of multiple target positions can be compared with the simulated tensile strength. When the difference between the actual tensile strength and the simulated tensile strength at the target position is greater than a preset threshold, the process simulation parameters of the casting are adjusted and the die-casting process of the casting is re-simulated.

[0135] Exemplarily, when the difference between the actual tensile strength at the target position and the simulated tensile strength is greater than a preset threshold, it indicates that the finite element model simulated tensile strength of the casting is significantly different from the actual tensile strength of the casting, and there may be problems in the casting process simulation process of the casting, resulting in inaccurate finite element model simulated tensile strength of the casting. The determination device can adjust the process simulation parameters of the casting, re-simulate the die-casting process of the casting, and determine the finite element model simulated tensile strength of the casting based on the re-simulated die-casting process simulation results, until the difference between the actual tensile strength at the target position and the simulated tensile strength is less than a preset threshold. Among them, the preset threshold is set by relevant technical personnel or management personnel according to actual conditions and needs, and the embodiments of the present application do not limit this.

[0136] As an example, Fig.12 FIG. 1 is a schematic diagram showing a comparison between the actual tensile strength and the simulated tensile strength of a casting according to an exemplary embodiment. Fig.12 As shown, the target positions include: 1201, 1202, 1203, 1204, 1205, 1206, 1207 and 1208. The actual tensile strength and simulated tensile strength of each target position are shown in Table 1.

[0137] Table 1

[0138]

[0139] It can be seen from the data in Table 1 that the simulated tensile strength can generally reflect the distribution of the actual tensile strength.

[0140] It should be noted that when the mechanical properties are predicted for the first time, the device needs to be calibrated for the accuracy of the tensile strength prediction, that is, multiple positions of the casting are selected for sampling, the actual tensile strength of the sample is tested, and compared with the simulated tensile strength of the corresponding position. If the actual tensile strength is significantly different from the simulated tensile strength or the distribution pattern is inconsistent, the difference information of the simulated tensile strength is fed back to the process simulation department, and the process simulation department adjusts the process simulation parameters and re-simulates to obtain new results. This process is repeated until the prediction results can roughly reflect the distribution of the measured results.

[0141] It should be understood that the determination device compares the actual tensile strength of the casting with the simulated tensile strength in order to discover and correct the deviation of the simulation model of the casting, adjusts the process simulation parameters of the casting according to the actual tensile strength results, optimizes the simulation process of the die-casting process of the casting, and improves the accuracy of the die-casting process simulation of the casting.

[0142] In some other embodiments, the material performance parameters include: initial fatigue life parameters. The determination device can correct the initial fatigue life parameters based on the tensile strength value of each region to obtain the corresponding relationship between the mechanical response and fatigue life of each region. Fig.13 As shown, the above step S101 can be specifically implemented as the following steps S1011-S1012:

[0143] S1011. For each of the multiple regions, based on the tensile strength value of each region, correct the initial fatigue life parameter to obtain the fatigue life parameter corresponding to each region.

[0144] Among them, mechanical response includes stress and strain. Fatigue life parameters include stress-life fatigue strength coefficient, strain-life fatigue strength coefficient and cyclic strength coefficient.

[0145] It should be noted that the mechanical response may include stress and / or strain. When the mechanical response includes stress, the fatigue life parameter is the stress-life fatigue strength coefficient. When the mechanical response includes strain, the fatigue life parameter includes: strain-life fatigue strength coefficient and cyclic strength coefficient.

[0146] As a possible implementation manner, for each region among the multiple regions, the determination device may correct the initial fatigue life parameter based on the tensile strength value of each region to obtain the fatigue life parameter corresponding to each region.

[0147] Exemplarily, when the mechanical response includes stress, the corresponding relationship between the mechanical response and the fatigue life is an SN curve, and the fatigue life parameter includes: stress-life fatigue strength coefficient. The determination device can correct the initial fatigue life parameter of region i based on the following expression (4):

[0148]

[0149] in, represents the modified stress-life fatigue strength factor, represents the tensile strength value of region i, σ u Indicates the tensile strength value of the casting material.

[0150] As another example, when the mechanical response includes strain, the corresponding relationship between the mechanical response and the fatigue life is an EN curve, and the fatigue life parameters include: strain-life fatigue strength coefficient and cycle strength coefficient. The determination device can correct the initial fatigue life parameters of region i based on the following expressions (5) and (6):

[0151]

[0152] in, represents the modified strain-life fatigue strength factor, K ′i Represents the modified cyclic strength coefficient.

[0153] S1012. Determine the corresponding relationship between the mechanical response and fatigue life of each region based on the fatigue life parameter corresponding to each region.

[0154] As a possible implementation manner, after the determination device determines the fatigue life parameters corresponding to each region, the corresponding relationship between the mechanical response and the fatigue life of each region can be determined based on the fatigue life parameters corresponding to each region.

[0155] As an example, the determination device corrects the cyclic stress-strain curve parameters of the base material of the integrated die-cast floor according to the tensile strength values ​​of 247MPa, 227MPa, 207MPa and 187MPa of the four regions of the integrated die-cast floor, and obtains the cyclic stress-strain curves corresponding to the four regions. Fig.14 is a cyclic stress-strain curve diagram of each region of a casting according to an exemplary embodiment. Fig.14 As shown in the figure, Al_base represents the cyclic stress-strain curve of the base material of the casting, Al_UTS247, Al_UTS227, Al_UTS207 and Al_UTS187 represent the cyclic stress-strain curves of the regions where the tensile strength of the casting is 247MPa, 227MPa, 207MPa and 187MPa, respectively. The ordinate is the stress amplitude, the unit is MPa, and the value range is 0-300. The abscissa is the strain amplitude, the unit is uE, and the value range is 0-1.2E4. The changing trends of the cyclic stress-strain of the base material and the four regions of the floor after integrated die-casting are shown in the figure. Fig.14 shown.

[0156] The determination device corrects the EN curve parameters of the base material of the integrated die-casting floor to obtain EN curves corresponding to the four regions. Fig.15 is an EN curve diagram of each region of a casting according to an exemplary embodiment. Fig.15 As shown in the figure, Al_base represents the EN curve of the base material of the casting, Al_UTS247, Al_UTS227, Al_UTS207 and Al_UTS187 represent the EN curves of the areas where the tensile strength of the casting is 247MPa, 227MPa, 207MPa and 187MPa respectively, the ordinate is the strain amplitude, the unit is uE, the value range is 1000-14, the abscissa is the life, the unit is the number of cycles, the value range is 100-1E8, the change trend of the strain life of the base material and the four areas of the floor after integrated die casting is shown in the figure. Fig.15 shown.

[0157] It should be understood that the determination device corrects the initial fatigue life parameters based on the tensile strength values ​​of different regions to determine the correspondence between the mechanical response and fatigue life of each region, thereby realizing customized fatigue life assessment of different regions of the casting, taking into account the performance differences of different regions of the casting, and improving the accuracy of fatigue performance analysis of the casting.

[0158] In some other embodiments, the determining device may determine the mechanical response of the casting under the simulated working condition, thereby determining the fatigue damage of the casting based on the mechanical response. Fig.16 As shown, the above step S102 can be specifically implemented as the following steps S1021-S1023:

[0159] S1021. Based on the finite element model of the casting, determine the mechanical response of the casting under the simulation condition.

[0160] As a possible implementation manner, the determination device may determine the mechanical response of the casting under the simulation condition based on a finite element model of the casting.

[0161] S1022. Based on the mechanical response of the casting under the simulation condition, the fatigue damage of each region under the simulation condition is calculated according to the corresponding relationship between the mechanical response and fatigue life of each region.

[0162] As a possible implementation method, the determination device can calculate the fatigue damage of each unit in each area under the simulation condition based on the mechanical response of the casting under the simulation condition and the corresponding relationship between the mechanical response and fatigue life of each area.

[0163] For example, when the correspondence between the mechanical response and the fatigue life is an SN curve, the determination device can calculate the fatigue damage of each unit in each region under the simulation condition based on the following expression (7) and Miner or other fatigue damage accumulation theory:

[0164]

[0165] Among them, σ α represents the stress level on the element or element node, Indicates the fatigue strength coefficient of the modified SN curve.

[0166] When the corresponding relationship between the mechanical response and the fatigue life is a cyclic stress-plastic strain curve and an EN curve, the determination device can calculate the fatigue damage of each unit in each region under the simulation condition based on the following expressions (8), (9) and Miner or other fatigue damage accumulation theories:

[0167]

[0168] σ α =K ′i (ε pa ) n′ (9);

[0169] Among them, ε α represents the overall strain on the element or element node, ε pa represents plastic strain, E represents the elastic modulus of the casting material, Indicates the fatigue strength coefficient of the modified EN curve, K ′i Represents the modified cyclic strength coefficient.

[0170] S1023. Determine the fatigue damage of the casting based on the fatigue damage in each region under the simulated working condition.

[0171] As a possible implementation manner, after the determination device determines the fatigue damage of each unit in each region under the simulation condition, the fatigue damage of the casting can be determined based on the fatigue damage of each unit in each region under the simulation condition.

[0172] Exemplarily, the determining device may determine the fatigue damage of the casting under the simulated working condition based on the fatigue damage of each unit in each region under the simulated working condition.

[0173] As an example, the determination device can calculate the stress of the integrated die-cast floor under the simulation condition by using ABAQUS finite element solution software, and then use nCode software to calculate fatigue damage. The setting of the material fatigue parameters of each area of ​​the integrated die-cast floor in nCode software is shown in Table 2.

[0174] Table 2

[0175] Material Group Material Name database PART-1-1_ELEMENT_SET_UTS187 Al_UTS187 aluminium_en PART-1-1_ELEMENT_SET_UTS207 Al_UTS207 aluminium_en PART-1-1_ELEMENT_SET_UTS227 Al_UTS227 aluminium_en PART-1-1_ELEMENT_SET_UTS247 Al_UTS247 aluminium_en Default Material Al_base aluminium_en

[0176] Among them, Table 2 includes: material group, material name and database, and the material name and database corresponding to each material group are shown in Table 2. Among them, PART-1-1_ELEMENT_SET_UTS187, PART-1-1_ELEMENT_SET_UTS207, PART-1-1_ELEMENT_SET_UTS227, and PART-1-1_ELEMENT_SET_UTS247 respectively represent the unit sets established for region 1, region 2, region 3, and region 4 of the integrated die-casting floor in the ABAQUS finite element calculation model.

[0177] It should be understood that the above embodiment takes the integrated die-cast rear floor as an example to describe the implementation process of the fatigue of the casting fatigue damage determination method of the embodiment of the present application. The casting fatigue damage determination method provided in the embodiment of the present application can be used for fatigue simulation calculations of parts and components, and can also be used for fatigue simulation calculations at the vehicle level or system level. For fatigue simulation at the vehicle level or system level, it is only necessary to perform special treatment on the annual target castings during fatigue damage calculation, and other processes are consistent with the conventional vehicle level or system level fatigue simulation process.

[0178] Fig.17 is a flow chart of another method for determining fatigue damage of a casting according to an exemplary embodiment. Fig.17 As shown, the process includes the following steps: S1701, basic material performance parameter acquisition (equivalent to the above step S501). S1702, tensile strength distribution prediction (equivalent to the above step S502). S1703, casting area division (equivalent to the above step S100). S1704, fatigue parameter mapping of different regional materials (equivalent to the above step S101). S1705, casting fatigue simulation calculation (equivalent to the above step S102).

[0179] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of the method. In order to achieve the above functions, the casting fatigue damage determination device or electronic device includes a hardware structure and / or software module corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0180] The embodiment of the present application can divide the functional modules of the casting fatigue damage determination device or electronic device according to the above method. For example, the casting fatigue damage determination device or electronic device can include various functional modules corresponding to the various functional divisions, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation.

[0181] Fig.18 is a block diagram of a casting fatigue damage determination device according to an exemplary embodiment. Fig.18The casting fatigue damage determination device 1800 includes: a determination module 1801. The determination module 1801 is used to determine the corresponding relationship between the mechanical response and fatigue life of each region of the casting based on the tensile strength value of each region in the multiple regions of the casting; the determination module 1801 is also used to determine the fatigue damage of the casting based on the corresponding relationship between the mechanical response and fatigue life of each region.

[0182] In a possible implementation, the device further includes: a division module 1802. The division module 1802 is used to divide the casting into multiple regions based on the tensile strength distribution data of the casting; the tensile strength distribution data is used to characterize the distribution of the maximum tensile stress that the casting can withstand when subjected to a tensile force.

[0183] In another possible implementation, the tensile strength distribution data includes: the tensile strength value of each unit in the finite element model of the casting; a division module 1802, which is specifically used to determine multiple tensile strength value ranges based on the tensile strength value of each unit in the finite element model of the casting; based on the multiple tensile strength value ranges, divide the area in the finite element model of the casting that belongs to the same tensile strength value range into one area, thereby obtaining multiple areas.

[0184] In another possible implementation, the device further includes: a testing module 1803. The testing module 1803 is used to perform a mechanical test on a tensile test specimen of a raw material of the casting to obtain material performance parameters of the raw material of the casting; and the determination module 1801 is further used to determine the tensile strength distribution data of the casting based on the material performance parameters.

[0185] In another possible implementation, the material performance parameters include: the tensile strength of the material of the casting; determining module 1801, which is specifically used to simulate the die-casting process of the casting to obtain the die-casting process simulation results of the casting; determining the tensile strength distribution of the casting based on the material tensile strength and the die-casting process simulation results; mapping the tensile strength distribution to the finite element model of the casting to obtain the tensile strength distribution data of the casting.

[0186] In another possible implementation, the device further includes: a measuring module 1804 and an adjusting module 1805. The measuring module 1804 is used to sample the target position of the casting and measure the actual tensile strength of the target position; the determining module 1801 is also used to determine the simulated tensile strength of the target position based on the tensile strength distribution data of the casting; the adjusting module 1805 is used to adjust the process simulation parameters of the casting and re-simulate the die casting process of the casting when the difference between the actual tensile strength and the simulated tensile strength of the target position is greater than a preset threshold.

[0187] In another possible implementation, the material performance parameters include: an initial fatigue life parameter; a determination module 1801, which is specifically used to correct the initial fatigue life parameter for each region among the multiple regions based on the tensile strength value of each region to obtain the fatigue life parameter corresponding to each region; based on the fatigue life parameter corresponding to each region, determine the correspondence between the mechanical response and fatigue life of each region.

[0188] In yet another possible implementation, the mechanical response includes stress and strain; and the fatigue life parameters include stress-life fatigue strength coefficient, strain-life fatigue strength coefficient and cyclic strength coefficient.

[0189] In another possible implementation, the determination module 1801 is specifically used to determine the mechanical response of the casting under the simulation condition based on the finite element model of the casting; based on the mechanical response of the casting under the simulation condition, calculate the fatigue damage of each region under the simulation condition according to the correspondence between the mechanical response and fatigue life of each region; based on the fatigue damage of each region under the simulation condition, determine the fatigue damage of the casting.

[0190] According to the above technical means, the casting is divided into multiple regions, and the corresponding relationship between the mechanical response and fatigue life of each region is determined respectively, taking into account the influence of the uneven distribution of the material properties of the casting on the fatigue performance of the casting, so as to more accurately determine the influence of the fatigue performance of different regions of the casting on the fatigue performance of the casting, thereby more accurately determining the fatigue damage of the casting, and improving the reliability and accuracy of determining the fatigue damage of the casting. In addition, based on the corresponding relationship between the mechanical response and fatigue life of each region, different regions of the casting can be designed more reasonably to improve the fatigue durability performance of the key regions of the casting.

[0191] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0192] Fig.19 FIG. 1 is a block diagram of an electronic device according to an exemplary embodiment. Fig.19 As shown, the electronic device 1900 includes but is not limited to: a processor 1901 and a memory 1902 .

[0193] The memory 1902 is used to store executable instructions of the processor 1901. It can be understood that the processor 1901 is configured to execute instructions to implement the casting fatigue damage determination method in the above embodiment.

[0194] It should be noted that those skilled in the art can understand that Fig.19The electronic device structure shown in the figure does not constitute a limitation on the electronic device, and the electronic device may include Fig.19 More or fewer components may be shown, or certain components may be combined, or the components may be arranged differently.

[0195] The processor 1901 is the control center of the electronic device. It uses various interfaces and lines to connect various parts of the entire electronic device. By running or executing software programs and / or modules stored in the memory 1902, and calling data stored in the memory 1902, it performs various functions of the electronic device and processes data, thereby monitoring the electronic device as a whole. The processor 1901 may include one or more processing units. Optionally, the processor 1901 may integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, user interface, and application programs, and the modem processor mainly processes wireless communications. It is understandable that the above-mentioned modem processor may not be integrated into the processor 1901.

[0196] The memory 1902 may be used to store software programs and various data. The memory 1902 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application program required by at least one functional module (such as a determination unit, a processing unit, etc.), etc. In addition, the memory 1902 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0197] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory 1902 including instructions, and the above instructions can be executed by the processor 1901 of the electronic device 1900 to implement the casting fatigue damage determination method in the above embodiment.

[0198] In actual implementation, Fig.18 The functions of the determination module 1801, the division module 1802, the test module 1803, the measurement module 1804 and the adjustment module 1805 can all be implemented by Fig.19 The processor 1901 in the embodiment calls the computer program stored in the memory 1902 to implement. The specific execution process can refer to the description of the method part in the above embodiment, which will not be repeated here.

[0199] Optionally, the computer-readable storage medium may be a non-temporary computer-readable storage medium, for example, the non-temporary computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0200] In an exemplary embodiment, the present application also provides a computer program product including one or more instructions, which can be executed by a processor 1901 of an electronic device to complete the casting fatigue damage determination method in the above embodiment.

[0201] It should be noted that when the instructions in the above-mentioned computer-readable storage medium or one or more instructions in the computer program product are executed by the processor of the electronic device, the various processes of the above-mentioned method embodiment are implemented, and the same technical effect as the above-mentioned method can be achieved. To avoid repetition, they will not be repeated here.

[0202] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0203] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0204] The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0205] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0206] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or the full classification part or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium, including a number of instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute the full classification part or part of the steps of each embodiment method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, ROM, RAM, disk or CD and other media that can store program code.

[0207] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application 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.

Claims

1. A method for determining fatigue damage of a casting, characterized in that: The method comprises: Determining a corresponding relationship between a mechanical response and a fatigue life of each region of the casting based on a tensile strength value of each region of the casting; Based on the corresponding relationship between the mechanical response and fatigue life of each region, the fatigue damage of the casting is determined.

2. The method according to claim 1, characterized in that The method further comprises: The casting is divided into a plurality of regions based on the tensile strength distribution data of the casting; the tensile strength distribution data is used to characterize the distribution of the maximum tensile stress that the casting can withstand when subjected to a tensile force.

3. The method according to claim 2, characterized in that The tensile strength distribution data includes: the tensile strength value of each unit in the finite element model of the casting; the casting is divided into a plurality of regions based on the tensile strength distribution data of the casting, including: Determining a plurality of tensile strength value ranges based on the tensile strength value of each element in the finite element model of the casting; Based on the multiple tensile strength value ranges, regions in the finite element model of the casting belonging to the same tensile strength value range are divided into one region to obtain the multiple regions.

4. The method according to any one of claims 1 to 3, characterized in that: The method further comprises: Performing mechanical testing on a tensile test specimen of the raw material of the casting to obtain material performance parameters of the raw material of the casting; Based on the material property parameters, tensile strength distribution data of the casting is determined.

5. The method according to claim 4, characterized in that The material performance parameters include: the material tensile strength of the casting; and determining the tensile strength distribution data of the casting based on the material performance parameters includes: Simulating the die-casting process of the casting to obtain a simulation result of the die-casting process of the casting; Determining the tensile strength distribution of the casting based on the tensile strength of the material and the die-casting process simulation result; The tensile strength distribution is mapped to a finite element model of the casting to obtain tensile strength distribution data of the casting.

6. The method according to claim 5, characterized in that The method further comprises: Sampling a target position of the casting and measuring an actual tensile strength of the target position; Determining the simulated tensile strength of the target position based on the tensile strength distribution data of the casting; When the difference between the actual tensile strength at the target position and the simulated tensile strength is greater than a preset threshold, the process simulation parameters of the casting are adjusted, and the die-casting process of the casting is re-simulated.

7. The method according to claim 4, characterized in that The material performance parameters include: initial fatigue life parameters; the corresponding relationship between the mechanical response and fatigue life of each region of the casting is determined based on the tensile strength value of each region of the casting, including: For each region among the multiple regions, based on the tensile strength value of each region, correcting the initial fatigue life parameter to obtain the fatigue life parameter corresponding to each region; Based on the fatigue life parameter corresponding to each region, the corresponding relationship between the mechanical response and the fatigue life of each region is determined.

8. The method according to claim 7, characterized in that The mechanical response includes stress and strain; the fatigue life parameters include stress-life fatigue strength coefficient, strain-life fatigue strength coefficient and cyclic strength coefficient.

9. The method according to any one of claims 1 to 3, characterized in that: The step of determining fatigue damage of the casting based on the fatigue life curve of each region comprises: Determining the mechanical response of the casting under the simulation condition based on the finite element model of the casting; Based on the mechanical response of the casting under the simulation working condition, the fatigue damage of each region under the simulation working condition is calculated according to the corresponding relationship between the mechanical response and fatigue life of each region; Based on the fatigue damage of each region under the simulated working condition, the fatigue damage of the casting is determined.

10. A casting fatigue damage determination device, characterized in that: The device comprises: a determination module; The determination module is used to determine the corresponding relationship between the mechanical response and fatigue life of each region of the casting based on the tensile strength value of each region of the multiple regions of the casting; The determination module is further used to determine the fatigue damage of the casting based on the corresponding relationship between the mechanical response and fatigue life of each region.

11. An electronic device, characterized in that: include: processor; a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the method as claimed in any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that: When the computer-executable instructions stored in the computer-readable storage medium are executed by a processor of an electronic device, the electronic device is capable of performing the method as claimed in any one of claims 1 to 9.

13. A computer program product, characterized in that The computer program product comprises computer instructions, and when the computer instructions are executed on an electronic device, the electronic device is caused to perform the method according to any one of claims 1 to 9.

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