Vehicle body simulation method and related device

Abstract

The invention discloses a vehicle body simulation method and a related device, and relates to the field of data processing, and the method comprises the steps: determining a material constitutive curve group of each first casting simulation unit of each vehicle body part related to a to-be-simulated vehicle body according to a mechanical property prediction result, obtained through vehicle body part casting simulation, at a specified strain rate; according to the method, the mechanical properties of all vehicle body parts at all positions under different strain rates are reflected, so that a material constitutive curve group of all vehicle body simulation units forming a to-be-simulated vehicle body is obtained through mapping, and detailed data support is provided for subsequent vehicle body simulation calculation; the accuracy of vehicle body simulation is improved by means of the differentiated material attribute parameters matched with the actual condition.

Description

Technical Field

[0001] The present application relates to the field of data processing technology, and in particular to a vehicle body simulation method and related devices. Background Art

[0002] Body simulation can refer to the prediction and calculation of the mechanical behavior of the vehicle body structure under collision and other working conditions, such as finite element collision simulation. When performing body simulation, it is necessary to import the material data of the body. The currently imported material data is generally uniform, that is, it is assumed that the material properties at each body position are the same.

[0003] However, the body parts of vehicles are mainly made through casting technology. In the casting process of parts gradually changing from liquid to solid, affected by factors such as material properties, flow process, solidification process, etc., the final castings often have different material properties and mechanical properties in different parts, that is, the actual material properties at each body position are different.

[0004] Therefore, the vehicle body simulation results obtained based on uniform material data usually deviate greatly from the actual results; based on this, how to improve the accuracy of vehicle body simulation has become a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] In view of the above problems, the present application provides a vehicle body simulation method and related devices to improve the accuracy of vehicle body simulation.

[0006] The specific plan is as follows: A first aspect of the present application provides a vehicle body simulation method, comprising: Acquire casting simulation data matching the mechanical test results of each body part; each body part is a part related to the body to be simulated, and the casting simulation data of each body part includes mechanical property prediction data of each first casting simulation unit constituting the current part at a specified strain rate, wherein the specified strain rate is a strain rate corresponding to the mechanical test result; Determine the mechanical property data of each first casting simulation unit according to the acquired casting simulation data, and generate a material constitutive curve group of each first casting simulation unit; the material constitutive curve corresponding to the specified strain rate in the material constitutive curve group of each first casting simulation unit matches the mechanical property data of the current first casting simulation unit; According to the material constitutive curve group of each first casting simulation unit, the material constitutive curve group of each vehicle body simulation unit is mapped to provide vehicle body simulation calculation; each vehicle body simulation unit constitutes the vehicle body to be simulated.

[0007] In a possible implementation, determining the mechanical property data of each first casting simulation unit according to the acquired casting simulation data includes: The mechanical property prediction data of each first casting simulation unit in the acquired casting simulation data is used as a data object to be clustered, and clustering processing is performed; Determine the mechanical property data of each first casting simulation unit; the mechanical property data of each first casting simulation unit is the mechanical property data of the cluster center of the cluster to which the current first casting simulation unit belongs, and the mechanical property data of each cluster center is determined based on the data objects constituting the cluster where the current cluster center is located.

[0008] In a possible implementation, the mechanical property data of each cluster center is the mean value of each data object constituting the cluster where the current cluster center is located.

[0009] In a possible implementation, generating a material constitutive curve group of each first casting simulation unit includes: performing the following steps on each first casting simulation unit: Determine a geometric transformation method; match a curve obtained by geometrically transforming a specified reference curve according to the geometric transformation method with the mechanical property data of the current first casting simulation unit, wherein the specified reference curve is a material constitutive curve corresponding to the specified strain rate in a reference material constitutive curve group; The respective curves in the reference material constitutive curve group are geometrically transformed according to the geometric transformation method to obtain the material constitutive curve group of the current first casting simulation unit.

[0010] In a possible implementation, mapping the material constitutive curve groups of each vehicle body simulation unit based on the material constitutive curve groups of each first casting simulation unit includes: Determine the data storage nodes of the material constitutive curve groups of the first casting simulation units as the first nodes, and form a first node set with the first nodes; Perform the following steps for each vehicle body simulation unit: Determine the data storage node of the current vehicle body simulation unit as the second node; Determine n nodes around the second node from the first node set 1 first nodes; wherein the n 1 is a preset positive integer; For the determined n 1 The material constitutive curve group of the first node is interpolated to obtain the material constitutive curve group of the current vehicle body simulation unit.

[0011] In a possible implementation, the casting simulation data of each vehicle body part further includes: casting residual stress prediction data of each second casting simulation unit constituting the current part, wherein the casting residual stress prediction data is obtained by casting deformation simulation; the method further includes: According to the casting residual stress prediction data of each second casting simulation unit, the casting residual stress data of each vehicle body simulation unit is mapped to obtain the casting residual stress data for performing the vehicle body simulation calculation.

[0012] In a possible implementation, mapping the casting residual stress data of each vehicle body simulation unit based on the casting residual stress data of each second casting simulation unit includes: Determine the data storage nodes of the casting residual stress prediction data of each second casting simulation unit as the third node, and each third node constitutes a third node set; Perform the following steps for each vehicle body simulation unit: Determine the data storage node of the current vehicle body simulation unit as the second node; Determine n nodes around the second node from the third node set 2 third nodes; wherein the n 2 is a preset positive integer; For the determined n 2 The casting residual stress prediction data of the third node is interpolated to obtain the casting residual stress data of the current body simulation unit.

[0013] A second aspect of the present application provides a vehicle body simulation device, comprising: a data acquisition unit, configured to acquire casting simulation data matching the mechanical test results of each body part; each body part is a part related to the body to be simulated, and the casting simulation data of each body part includes mechanical property prediction data of each first casting simulation unit constituting the current part at a specified strain rate, wherein the specified strain rate is a strain rate corresponding to the mechanical test results; A data processing unit, used to determine the mechanical property data of each first casting simulation unit according to the acquired casting simulation data, and generate a material constitutive curve group of each first casting simulation unit; the material constitutive curve corresponding to the specified strain rate in the material constitutive curve group of each first casting simulation unit is matched with the mechanical property data of the current first casting simulation unit; The data processing unit is also used to map the material constitutive curve group of each vehicle body simulation unit based on the material constitutive curve group of each first casting simulation unit for vehicle body simulation calculation; the vehicle body simulation units constitute the vehicle body to be simulated.

[0014] In a possible implementation, the data acquisition unit includes a casting simulation unit, which is used to perform the following steps for each body part related to the simulated body: Configure the casting simulation parameters of the current body parts; Perform casting simulation on current body parts to predict the mechanical properties of current body parts; Determine whether the predicted casting simulation data of the current body part matches the mechanical test result of the current body part. If so, output the casting simulation data of the current body part. Otherwise, return to the step of configuring the casting simulation parameters of the current body part.

[0015] A third aspect of the present application provides an electronic device, comprising at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs; The processor is used to execute the computer program so that the electronic device can implement the vehicle body simulation method of the above-mentioned first aspect or any implementation manner of the first aspect.

[0016] A fourth aspect of the present application provides a computer program product, comprising computer-readable instructions, which, when executed on an electronic device, enables the electronic device to implement the vehicle body simulation method of the first aspect or any implementation of the first aspect.

[0017] With the help of the above-mentioned technical scheme, the body simulation scheme provided in the present application utilizes the mechanical property prediction results under the specified strain rate obtained by the casting simulation of the body parts to determine the material constitutive curve group of each first casting simulation unit of each body part involved in the body to be simulated, reflecting the mechanical properties of each body part at each position under different strain rates. Based on this mapping, the material constitutive curve group of each body simulation unit constituting the body to be simulated is obtained, which provides detailed data support for subsequent body simulation calculations, and improves the accuracy of body simulation by means of differentiated material property parameters that match the actual situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The features, advantages and other aspects of the embodiments of the present disclosure will become clear to those skilled in the art by referring to the following detailed description in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the accompanying drawings are schematic and are only used to illustrate preferred embodiments, and are not to be considered as limiting the present application. In the accompanying drawings: Figure 1 A schematic diagram of a process flow of a vehicle body simulation method provided in this application; Figure 2 An example of a schematic diagram of a material constitutive curve is shown; Figure 3A schematic diagram of the uniaxial tensile strength distribution of a vehicle body to be simulated is shown; Figure 4 A schematic diagram of the yield strength distribution of a vehicle body to be simulated is shown; Figure 5 A schematic diagram of the elongation distribution of a vehicle body to be simulated is shown; Figure 6 A schematic diagram of the process of casting body integrated chain simulation is shown; Figure 7 A structural schematic diagram of a vehicle body simulation device provided in this application; Figure 8 A schematic diagram of the structure of an electronic device provided in this application. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] The embodiments of the present application provide a vehicle body simulation method and related devices to solve the data missing problem of vehicle body simulation tasks, especially the problem of missing material property data, thereby improving the accuracy of vehicle body simulation.

[0021] Figure 1 FIG. 1 is a flow chart of a vehicle body simulation method according to an embodiment of the present application. Figure 1 As shown, the method may include: Step S101: Acquire casting simulation data matching the mechanical test results of each vehicle body part.

[0022] Among them, each body part is a part related to the body to be simulated. It should be noted that since the casting process, material properties, etc. of different body parts are often different, casting simulation is usually performed on a part-by-part basis; and body simulation, such as finite element collision simulation, requires the entire body-in-white related parts of the vehicle to be connected as a whole through unit binding for simulation calculation, that is, the simulation scope of the subsequent body simulation includes each body part related to the body to be simulated. Based on this, obtaining the casting simulation data of each body part can provide data support for the subsequent body simulation.

[0023] In addition, when performing the casting simulation of the body parts, the body parts to be simulated are usually divided into several grid units for numerical simulation calculation, and the grid units can be called casting simulation units. It should be noted that the grid division method used may be different based on the different types of casting parameters predicted by the casting simulation. Based on this, the grid unit used when predicting the mechanical properties of the casting based on the body parts can be called the first casting simulation unit. It should be noted that the present application does not limit the simulation unit, and the form of the simulation unit, the data storage method, etc. can all refer to the existing simulation operations. On the basis of the foregoing, the casting simulation data of each body part may include the mechanical property prediction data of each first casting simulation unit constituting the current part at a specified strain rate, wherein the specified strain rate is the strain rate corresponding to the mechanical test result. Specifically, the parameter types involved in the mechanical test results, mechanical property prediction data and mechanical property data described in the present application may include: uniaxial tensile strength, yield strength and elongation.

[0024] Mechanical tests on body parts are generally conducted according to certain standards to ensure the consistency and comparability of the test results. The mechanical test results obtained are the test results under the corresponding standards. The mechanical test results of body parts are obtained by testing the test samples according to the standards. For example, the test samples can correspond to the specified points on the body parts. The mechanical test results of the test samples can only reflect the actual mechanical properties of the body parts to a certain extent. Due to the limitations of the casting process, they cannot reflect the actual mechanical properties at the positions of each part.

[0025] In order to ensure that the prediction results obtained through the casting simulation of body parts are accurate and reliable, the prediction results can be corrected in combination with the mechanical test results of the body parts. Specifically, the casting simulation process can be adjusted so that the mechanical property prediction results obtained by the casting simulation match the mechanical test results, such as the mechanical property prediction results at a specified point match the mechanical test results. Exemplarily, the above-mentioned adjustment of the casting simulation process can be performed based on the test standard followed by the mechanical test results. On the basis of the foregoing content, taking a body part A as an example, the casting simulation data of body part A that matches the mechanical test results of body part A obtained in step S101 can refer to the data under the current mechanical test result standard, and can also be referred to as the data under the first test standard. The first test standard is the test standard followed by the mechanical test results in step S101.

[0026] Based on this, this embodiment provides accurate, reliable and rich mechanical performance prediction data for subsequent body simulation by using casting simulation data that matches the mechanical test results of each body part, thereby providing a basis for improving the accuracy of body simulation.

[0027] Step S102: determining the mechanical property data of each first casting simulation unit according to the acquired casting simulation data, and generating a material constitutive curve group of each first casting simulation unit.

[0028] The first casting simulation units described in step S102 include first casting simulation units of various body parts related to the body to be simulated. Exemplarily, determining the mechanical property data of each first casting simulation unit based on the acquired casting simulation data may include: determining the acquired mechanical property prediction data of each first casting simulation unit as the mechanical property data of each first casting simulation unit.

[0029] It should be noted that there is a large gap between the mechanical data obtained through casting simulation and the mechanical data required for body simulation. When performing body simulation, each unit requires a set of material constitutive curves. This set of material constitutive curves (i.e., the material constitutive curve group described in this application, which can also be called a material constitutive curve family) is composed of material constitutive curves at different strain rates. Any material constitutive curve has stress as the vertical axis and strain as the horizontal axis, so it can also be called a stress-strain curve. Based on this, compared with the mechanical data required for body simulation, the mechanical data obtained through casting simulation has a large gap in data volume and data information, and cannot be directly mapped to obtain the data required for body simulation; that is, it is necessary to expand the curve of the mechanical data obtained from casting simulation to generate a material constitutive curve group.

[0030] The generated material constitutive curve group satisfies the following conditions: the material constitutive curve corresponding to the specified strain rate in the material constitutive curve group of each first casting simulation unit matches the mechanical property data of the current first casting simulation unit; this condition is also the basis for generating the material constitutive curve group in step S102.

[0031] The following is an explanation of the types of mechanical performance parameters involved in this application (uniaxial tensile strength, yield strength and elongation). Uniaxial tensile strength can refer to the maximum engineering stress that a component can withstand under uniaxial tension, corresponding to the peak point on the stress-strain curve; yield strength can refer to the minimum stress value when a component begins to undergo permanent plastic deformation. In practical applications, the stress when the component produces 0.2% plastic strain can also be used as the yield strength. In addition, the upper yield strength or lower yield strength can also be used as the yield strength. The upper yield strength refers to the maximum stress before the component yields and the force drops for the first time. The lower yield strength refers to the minimum stress of the component during the yield period without considering the initial transient effect. The specific definition of yield strength is not limited in this application; elongation can refer to the permanent elongation percentage of the gauge length after the component breaks under tension, reflecting the plastic deformation capacity, corresponding to the maximum strain value in the stress-strain curve.

[0032] On the basis of the above, Figure 2 An example of a schematic diagram of a material constitutive curve is shown. Figure 2 The curve shown has stress as the vertical axis, with the stress unit being megapascal (MPa), and strain as the horizontal axis, with the strain unit being millimeters / millimeter (mm / mm), wherein the data point P representing the uniaxial tensile strength is shown. 1 , data point P representing yield strength 2 And the data point P representing the elongation 3 .

[0033] The material constitutive curve group of each first casting simulation unit is consistent with the material data format required for the subsequent body simulation. However, when the body simulation is performed on the entire body connected by each body part, the grid division method adopted is different from the grid division method in the casting simulation, so that the material constitutive curve group of each first casting simulation unit generated in step S102 cannot be directly provided for the body simulation. To solve this problem, the following step S103 is performed.

[0034] Step S103: mapping the material constitutive curve groups of each vehicle body simulation unit based on the material constitutive curve groups of each first casting simulation unit to provide for vehicle body simulation calculation.

[0035] Wherein, each of the vehicle body simulation units constitutes the vehicle body to be simulated.

[0036] This embodiment uses the mechanical property prediction results under a specified strain rate obtained from the casting simulation of the body parts to determine the material constitutive curve group of each first casting simulation unit of each body part involved in the body to be simulated, reflecting the mechanical properties of each body part at each position under different strain rates. Based on this mapping, the material constitutive curve group of each body simulation unit that constitutes the body to be simulated is obtained, which provides detailed data support for subsequent body simulation calculations and improves the accuracy of body simulation by means of differentiated material property parameters that match the actual situation.

[0037] In addition, since casting defects will deteriorate the performance of parts, such as causing parts to become brittle, reduce strength, and reduce toughness, and the defects of castings can be reflected by the mechanical property parameters of castings, that is, the mechanical property prediction data obtained through casting simulation can reflect the defects of body parts to a certain extent, the body simulation scheme provided in this embodiment, through the material constitutive curve group of each body simulation unit, realizes the utilization of defect data obtained from the casting stage, takes into account the impact of part defects on body simulation, thereby improving the accuracy of body simulation.

[0038] In one or more embodiments provided in the present application, the above-mentioned step S101 of obtaining casting simulation data matching the mechanical test results of each body part may include: performing the following steps A1-A4 for each body part related to the simulated body: Step A1: configure the casting simulation parameters of the current body part.

[0039] Step A2: performing casting simulation on the current body parts to predict the mechanical properties of the current body parts.

[0040] For example, the casting simulation performed when predicting the mechanical properties of the vehicle body parts may include: casting filling simulation and casting solidification simulation. In addition, the above casting simulation task may be implemented based on die casting mold flow analysis software.

[0041] Step A3: determine whether the predicted casting simulation data of the current body part matches the mechanical test result of the current body part. If so, execute step A4; otherwise, return to execute step A1.

[0042] Step A4: output the casting simulation data of the current vehicle body part.

[0043] Based on the above content, a connection is established between the mutually independent casting simulation and body simulation, realizing the chain simulation task of casting body integration; and data transmission between the casting simulation and the body simulation is realized through steps S102-S103, providing data support for realizing high-accuracy body simulation tasks.

[0044] For example, Figure 3-Figure 5 The schematic diagrams of the uniaxial tensile strength distribution, yield strength distribution and elongation distribution of a simulated vehicle body are shown respectively, wherein the values ​​of the predicted results of the mechanical properties of the simulated vehicle body at different positions are shown in different colors. Figure 3-Figure 5 As shown in the figure, there are large differences in the values ​​at different positions of the vehicle body, and the material types of the first casting simulation unit related to the simulated vehicle body may be as high as millions. Based on this, if the mechanical property prediction results are directly used as mechanical property data, it may lead to a large data processing pressure when subsequently generating material constitutive curve groups and performing grid parameter mapping; in addition, the simulation software on which the vehicle body simulation relies may not be able to accommodate millions of data.

[0045] To solve the above problem, in one or more embodiments provided in the present application, the above step S102, determining the mechanical property data of each first casting simulation unit according to the acquired casting simulation data, may include: Step B: taking the mechanical property prediction data of each first casting simulation unit in the acquired casting simulation data as the data object to be clustered, and performing clustering processing.

[0046] Exemplarily, the data object corresponding to a first casting simulation unit (denoted as unit i) can be represented as {σ b_i , σ s_i , δ i}, where σ b_i represents the predicted uniaxial tensile strength of element i, σ s_i represents the predicted yield strength of element i, δ i Represents the predicted value of elongation of unit i. The data objects corresponding to each first casting simulation unit constitute a data space.

[0047] Step C, determining the mechanical property data of each first casting simulation unit.

[0048] Specifically, the mechanical property data of each first casting simulation unit is the mechanical property data of the cluster center of the cluster to which the current first casting simulation unit belongs, and the mechanical property data of each cluster center is determined based on the data objects constituting the cluster to which the current cluster center belongs.

[0049] Based on the above content, this embodiment reduces the number of material types through clustering processing, alleviates the data processing pressure and calculation complexity of the material property data configuration process for body simulation, and reduces the complexity of body simulation import parameters, which helps to improve body simulation efficiency.

[0050] Optionally, the mechanical property data of each cluster center is the mean value of each data object constituting the cluster where the current cluster center is located.

[0051] The clustering process is described below by taking K-means clustering as an example. The above clustering process may include the following steps B1-B5: Step B1: Randomly select K data objects from the data space as initial clustering centers.

[0052] Where K represents the number of clusters specified by the K-means clustering algorithm. Each selected data object represents a cluster center.

[0053] Step B2: Calculate the distance (such as Euclidean distance) between each data object in the data space and each cluster center, determine the cluster to which each data object belongs based on the principle of the shortest distance, and calculate the objective function value.

[0054] Specifically, the cluster to which any data object belongs is the cluster to which the cluster center closest to the current data object belongs. The objective function of K-means can refer to: minimizing the sum of squares of distances from each data object to the corresponding cluster center, and the calculated objective function value is the sum of squares of distances from each data object to the corresponding cluster center.

[0055] Step B3: based on the clustering result of step B2, update the cluster center and calculate a new objective function value.

[0056] Exemplarily, for each of the K clusters, the data means corresponding to each data object belonging to the current cluster are calculated, specifically including the mean of uniaxial tensile strength, the mean of yield strength and the mean of elongation, and then the calculated mean is used as the new cluster center of the current cluster to update the cluster center of the current cluster. Correspondingly, the cluster center of the current cluster used in step B2 can be referred to as the previous cluster center of the current cluster. Optionally, the cluster center can also be updated based on other feature values ​​corresponding to each data object, and the specific update method is not limited in this application.

[0057] Step B4: determine whether the re-clustering condition is met. If so, return to execute step B2 based on the updated cluster center; otherwise, execute step B5.

[0058] Among them, the re-clustering conditions include: the numerical change of the objective function (that is, the objective function value calculated in step B2 is inconsistent with the new objective function value calculated in step B3, or the difference between the two exceeds a preset first difference threshold), or the cluster center of at least one of the K clusters changes (that is, the new cluster center is inconsistent with the previous cluster center, or the difference between the two exceeds a preset second difference threshold).

[0059] Step B5: Output the current classification status of each cluster center and data object as the clustering processing result.

[0060] Combination Figure 3-Figure 5 As shown, the prediction results of the mechanical properties of body parts are generally relatively concentrated in a relatively narrow parameter range. Based on this, when using K-means for clustering processing, the defect of poor clustering effect caused by noise can be avoided to a certain extent, that is, K-means clustering can be used to implement the clustering tasks required by this application.

[0061] Optionally, the value range of the parameter K can be in the range of tens to hundreds, and the specific value of K can be set according to actual conditions. In addition, other clustering algorithms can also be used when performing clustering processing, and this application does not limit this.

[0062] In one or more embodiments provided in the present application, the above-mentioned step S102, generating a material constitutive curve group of each first casting simulation unit, may include: performing the following steps D1-D2 on each first casting simulation unit: Step D1, determine the geometric transformation method.

[0063] Among them, the above-mentioned geometric transformation method satisfies: the curve obtained by geometrically transforming the specified reference curve according to the geometric transformation method matches the mechanical property data of the current first casting simulation unit, and the specified reference curve is the material constitutive curve corresponding to the specified strain rate in the reference material constitutive curve group. It should be noted that the reference material constitutive curve group can be obtained by experimental testing of body parts, and the test standard corresponding to the reference material constitutive curve group matches the test standard of the above-mentioned mechanical test results, that is, the first test standard mentioned above, thereby ensuring that the material constitutive curve group obtained by expanding the mechanical property data is consistent with the actual material properties, thereby ensuring the accuracy and reliability of the material property data.

[0064] In addition, the above-mentioned geometric transformation methods may specifically include transformation methods such as stretching, scaling, and translation.

[0065] Step D2: geometrically transform each curve in the reference material constitutive curve group according to the geometric transformation method to obtain the material constitutive curve group of the current first casting simulation unit.

[0066] The above scheme determines the geometric transformation method based on the specified reference curve in the reference material constitutive curve group, and then transforms the reference material constitutive curve group accordingly, generates a constitutive relationship curve group that meets the current mechanical performance results, realizes the curve expansion task based on mechanical performance data, and provides a basis for meeting the data requirements of vehicle body simulation. In addition, this embodiment uses the same geometric transformation method to transform each curve in a curve group, thereby ensuring the direct relative relationship between the curves in the same group.

[0067] In one or more embodiments provided in the present application, the above step S103, mapping the material constitutive curve group of each vehicle body simulation unit according to the material constitutive curve group of each first casting simulation unit, may include the following steps EF: Step E: determine the data storage nodes of the material constitutive curve groups of each first casting simulation unit as the first nodes, and form a first node set with each first node.

[0068] It should be noted that when implementing simulation tasks for different purposes, the simulation unit grid forms are different and the data storage nodes are also different. For example, the grid form of the first casting simulation unit can be a hexahedron; the data storage node of the hexahedron unit can be the center point, that is, the data of a hexahedron unit specifically refers to the data at the center point of the hexahedron.

[0069] Step F: Execute the following steps F1-F3 for each vehicle body simulation unit: Step F1: determine the data storage node of the current vehicle body simulation unit as the second node.

[0070] Exemplarily, the grid form of the vehicle body simulation unit may be a shell; the data storage node of the shell unit grid may be the center of the shell, that is, the data of a shell unit grid may specifically refer to the data at the center of the shell.

[0071] Step F2: Determine n nodes around the second node from the first node set. 1 The first node.

[0072] Among them, the n 1 is a preset positive integer. In a possible implementation, an index may be performed based on the location of the second node, that is, a multi-dimensional space search may be performed. Exemplarily, a kd-tree (short for k-dimensional tree) may be used for spatial retrieval to ensure computational efficiency.

[0073] Step F3: 1 The material constitutive curve group of the first node is interpolated to obtain the material constitutive curve group of the current vehicle body simulation unit.

[0074] For example, the above interpolation calculation can be performed in a linear interpolation manner. 1 The value of n 1 The method of calculating the first node and the method of interpolation calculation are not limited in this application and can be set according to actual needs.

[0075] This embodiment maps the data of the casting simulation unit to the vehicle body simulation unit through grid interpolation, thereby realizing the task of transmitting mechanical performance data between different unit forms.

[0076] In one or more embodiments provided in the present application, the casting simulation data of each vehicle body part may further include: casting residual stress prediction data of each second casting simulation unit constituting the current part.

[0077] The casting residual stress prediction data is obtained by casting deformation simulation, which can be performed after casting solidification simulation. It should be noted that the casting deformation simulation can be based on the casting solidification simulation obtained by the mechanical test results, that is, the mechanical property prediction data and casting residual stress prediction data constituting the casting simulation data are all data after data correction, which match the test results.

[0078] On the basis of the above, the vehicle body simulation method provided in the embodiment of the present application may further include step S104: Step S104: mapping the casting residual stress data of each vehicle body simulation unit according to the casting residual stress prediction data of each second casting simulation unit to obtain the casting residual stress data for performing the vehicle body simulation calculation.

[0079] The second casting simulation unit may refer to a mesh unit used when predicting residual stress of a casting based on a vehicle body part.

[0080] Based on the above scheme, the residual stress data of body parts obtained by casting simulation provides further data support for body simulation.

[0081] Optionally, various casting simulation parameters involved in this application can be obtained through casting simulation. Based on this, Figure 6 The figure shows a schematic diagram of the process of casting body integrated chain simulation. Figure 6As shown, in the casting simulation stage of the body parts, the body parts to be simulated can be subjected to casting filling simulation, casting solidification simulation and casting deformation simulation in sequence. The mechanical property prediction data, including uniaxial tensile strength, yield strength and elongation data, are predicted through the casting solidification simulation. The casting residual stress prediction data are predicted through the casting deformation simulation. The mechanical property prediction data and the casting residual stress prediction data together constitute the casting simulation data of the body parts to be simulated. On this basis, data correction is performed based on the mechanical test results of the body parts. If the predicted casting simulation data does not match the mechanical test results, the casting simulation parameters are adjusted and the casting simulation is performed again until the casting simulation data matching the mechanical test results are obtained. Then enter the data transmission processing stage, in which the mechanical properties prediction data of each body part obtained are clustered and reduced in dimension (to obtain the mechanical properties data of each casting simulation unit), curve expansion processing (to obtain the material constitutive curve group of each casting simulation unit) and grid interpolation processing (to obtain the material constitutive curve group of each body simulation unit) in turn, and the material property data required for body simulation is obtained. In particular, the reference material constitutive curve group is used in the curve expansion processing, and the curve group can be derived from the casting stress-strain curve data obtained through testing; the casting body grid file is used in the grid interpolation processing to indicate each body simulation unit. In addition, in the data transmission processing stage, the obtained casting residual stress prediction data of each body part is also grid interpolated to obtain the residual stress data required for body simulation. In addition, it should be noted that the above-mentioned casting simulation task can be implemented based on casting simulation software (such as Zhizhu Chaoyun software). In a possible implementation, the various steps of the data transmission processing stage can be integrated in the casting simulation software to further process the data output by the casting simulation module for output port output. Finally, enter the body simulation stage to perform body simulation calculation. It should be noted that since body simulation and casting simulation are usually implemented based on different software, in order to ensure data compatibility, such as compatibility in data format, before importing the output data of the data transmission and processing stage into the body simulation software (such as body collision simulation software LS-Dyna, Abaqus, etc.), commercial software can be used for secondary development of the data import interface, and then the processed data can be imported into the body simulation software, ultimately realizing the integrated chain simulation process of the casting body.

[0082] Based on the above content, the filling, solidification and deformation of the body parts are simulated first, and the mechanical property prediction results (including uniaxial tensile strength, yield strength and elongation) corrected by mechanical test data and the casting residual stress prediction results are obtained; on this basis, the residual stress prediction results are grid interpolated, and the mechanical property prediction results are clustered and reduced in dimension, which greatly reduces the material types, and then the mechanical results are curve expanded to meet the needs of body simulation, and finally grid interpolation is performed for body simulation calculation.

[0083] In one or more embodiments provided in the present application, the above step S104, mapping the casting residual stress data of each vehicle body simulation unit according to the casting residual stress prediction data of each second casting simulation unit, may include the following steps GH: Step G: determine the data storage nodes of the casting residual stress prediction data of each second casting simulation unit as the third node, and each third node constitutes a third node set.

[0084] Exemplarily, the mesh form of the second casting simulation unit may be a tetrahedron; the data storage node of the tetrahedron unit may be a vertex, that is, the data of a tetrahedron unit specifically refers to the data at the vertex of the tetrahedron.

[0085] Step H: Perform the following steps H1-H3 for each vehicle body simulation unit: Step H1: determine the data storage node of the current vehicle body simulation unit as the second node.

[0086] Step H2: Determine n nodes around the second node from the third node set. 2 A third node.

[0087] Among them, the n 2 A preset positive integer.

[0088] Step H3: for the determined n 2 The casting residual stress prediction data of the third node is interpolated to obtain the casting residual stress data of the current body simulation unit.

[0089] It should be noted that for n 2 The value of n 2 The method of calculating the third node and the method of interpolation calculation are not limited in this application and can be set according to actual needs. In addition, the interpolation process of residual stress data and mechanical data (such as material constitutive curve group) is similar and can be referred to accordingly.

[0090] This embodiment maps the data of the casting simulation unit to the vehicle body simulation unit through grid interpolation, thereby realizing the residual stress data transmission task between different unit forms.

[0091] Below is n 2 =4 as an example to illustrate step S104. When executing step S104, the old grid includes each third node, and the new grid includes each second node. Step S104 is intended to map the residual stress data of the old grid to the new grid. Exemplarily, a "unit-node" table, a "node-coordinate (such as Cartesian coordinate)" table and a "node-data" table of the new grid and the old grid can be constructed, wherein the unit can be represented by a unit identifier, the node can be represented by a node identifier, and the data value in the "node-data" table of the new grid needs to be determined by grid interpolation. On this basis, a node of the new grid can be taken as the current node, and then the spatial coordinates of the current node can be indexed from the "node-coordinate" table according to the identifier of the current node, and then the position of the current node in the old grid is determined, and the position is represented by the third node identifier and relative position relationship of the old grid; optionally, the four third nodes of the old grid can be extracted, and the position relationship between the unit composed of the extracted four third nodes and the current node can be determined by the coordinates of the current node and the extracted four third nodes. After traversing all the third node combinations, the four third nodes related to the current node can be determined and expressed as reference nodes. Then the relative position relationship refers to the position relationship between the reference unit composed of the reference nodes and the current node, which can specifically include: the current node is inside the reference unit, the current node is at the intersection of multiple units, etc. Based on this, the weighting coefficient is determined using the distance relationship between the current node and the reference node, and then the residual stress data of the current node is calculated.

[0092] The vehicle body simulation device provided in the embodiment of the present application is described below. The vehicle body simulation device described below and the vehicle body simulation method described above can be referenced to each other.

[0093] Figure 7 Schematic diagram of the structure of a vehicle body simulation device disclosed in the embodiment of the present application. Figure 7 As shown, the device may include: The data acquisition unit 11 is used to acquire casting simulation data matching the mechanical test results of each body part; each body part is a part related to the body to be simulated, and the casting simulation data of each body part includes mechanical property prediction data of each first casting simulation unit constituting the current part at a specified strain rate, and the specified strain rate is a strain rate corresponding to the mechanical test result; The data processing unit 12 is used to determine the mechanical property data of each first casting simulation unit according to the acquired casting simulation data, and generate a material constitutive curve group of each first casting simulation unit; the material constitutive curve corresponding to the specified strain rate in the material constitutive curve group of each first casting simulation unit matches the mechanical property data of the current first casting simulation unit; The data processing unit 12 is also used to map the material constitutive curve group of each vehicle body simulation unit according to the material constitutive curve group of each first casting simulation unit, so as to perform vehicle body simulation calculation; the vehicle body simulation units constitute the vehicle body to be simulated.

[0094] In one or more embodiments provided in the present application, the data acquisition unit 11 may include a casting simulation unit, which is used to perform the following steps for each body part related to the simulated body: Configure the casting simulation parameters of the current body parts; Perform casting simulation on current body parts to predict the mechanical properties of current body parts; Determine whether the predicted casting simulation data of the current body part matches the mechanical test result of the current body part. If so, output the casting simulation data of the current body part. Otherwise, return to the step of configuring the casting simulation parameters of the current body part.

[0095] In one or more embodiments provided in the present application, the process of the data processing unit 12 determining the mechanical property data of each first casting simulation unit according to the acquired casting simulation data may include: The mechanical property prediction data of each first casting simulation unit in the acquired casting simulation data is used as a data object to be clustered, and clustering processing is performed; Determine the mechanical property data of each first casting simulation unit; the mechanical property data of each first casting simulation unit is the mechanical property data of the cluster center of the cluster to which the current first casting simulation unit belongs, and the mechanical property data of each cluster center is determined based on the data objects constituting the cluster where the current cluster center is located.

[0096] In one or more embodiments provided in the present application, the mechanical property data of each cluster center is the average value of each data object constituting the cluster where the current cluster center is located.

[0097] In one or more embodiments provided in the present application, the process of the data processing unit 12 generating a material constitutive curve group for each first casting simulation unit may include: performing the following steps on each first casting simulation unit: Determine a geometric transformation method; match a curve obtained by geometrically transforming a specified reference curve according to the geometric transformation method with the mechanical property data of the current first casting simulation unit, wherein the specified reference curve is a material constitutive curve corresponding to the specified strain rate in a reference material constitutive curve group; The respective curves in the reference material constitutive curve group are geometrically transformed according to the geometric transformation method to obtain the material constitutive curve group of the current first casting simulation unit.

[0098] In one or more embodiments provided in the present application, the process of the data processing unit 12 mapping the material constitutive curve group of each vehicle body simulation unit according to the material constitutive curve group of each first casting simulation unit may include: Determine the data storage nodes of the material constitutive curve groups of the first casting simulation units as the first nodes, and form a first node set with the first nodes; Perform the following steps for each vehicle body simulation unit: Determine the data storage node of the current vehicle body simulation unit as the second node; Determine n nodes around the second node from the first node set 1 first nodes; wherein the n 1 is a preset positive integer; For the determined n 1 The material constitutive curve group of the first node is interpolated to obtain the material constitutive curve group of the current vehicle body simulation unit.

[0099] In one or more embodiments provided in the present application, the casting simulation data of each vehicle body part further includes: casting residual stress prediction data of each second casting simulation unit constituting the current part, wherein the casting residual stress prediction data is obtained through casting deformation simulation.

[0100] On the basis of the above, the data processing unit 12 can also be used to: map the casting residual stress data of each body simulation unit according to the casting residual stress prediction data of each second casting simulation unit, so as to perform the body simulation calculation.

[0101] In one or more embodiments provided in the present application, the process in which the data processing unit 12 maps the casting residual stress data of each vehicle body simulation unit according to the casting residual stress prediction data of each second casting simulation unit may include: Determine the data storage nodes of the casting residual stress prediction data of each second casting simulation unit as the third node, and each third node constitutes a third node set; Perform the following steps for each vehicle body simulation unit: Determine the data storage node of the current vehicle body simulation unit as the second node; Determine n nodes around the second node from the third node set 2 third nodes; wherein the n 2 is a preset positive integer; For the determined n 2 The casting residual stress prediction data of the third node is interpolated to obtain the casting residual stress data of the current body simulation unit.

[0102] The vehicle body simulation device provided in the embodiment of the present application can be applied to electronic devices, such as terminals with data processing capabilities: such as mobile phones, computers, servers, etc. Optionally, Figure 8 The hardware structure diagram of the electronic device is shown in FIG. Figure 8 , the hardware structure of the electronic device may include: at least one processor 1, at least one communication interface 2, at least one memory 3 and at least one communication bus 4; In the embodiment of the present application, the number of the processor 1, the communication interface 2, the memory 3, and the communication bus 4 is at least one, and the processor 1, the communication interface 2, and the memory 3 communicate with each other through the communication bus 4; The processor 1 may be a central processing unit CPU, or an application-specific integrated circuit ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present invention, etc.; The memory 3 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), etc., such as at least one disk memory; The memory is used to store computer programs, and the processor is used to execute the computer programs, so that the electronic device can implement any of the above-mentioned vehicle body simulation methods.

[0103] A storage medium is also provided in an embodiment of the present application. The storage medium carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement any vehicle body simulation method provided in the embodiment of the present application.

[0104] An embodiment of the present application also provides a computer program product including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device can implement any vehicle body simulation method provided in the embodiment of the present application.

[0105] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0106] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can refer to each other.

[0107] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A vehicle body simulation method, characterized in that: include: Acquire casting simulation data matching the mechanical test results of each body part; each body part is a part related to the body to be simulated, and the casting simulation data of each body part includes mechanical property prediction data of each first casting simulation unit constituting the current part at a specified strain rate, wherein the specified strain rate is a strain rate corresponding to the mechanical test result; Determine the mechanical property data of each first casting simulation unit according to the acquired casting simulation data, and generate a material constitutive curve group of each first casting simulation unit; The material constitutive curve corresponding to the specified strain rate in the material constitutive curve group of each first casting simulation unit matches the mechanical property data of the current first casting simulation unit; According to the material constitutive curve group of each first casting simulation unit, the material constitutive curve group of each vehicle body simulation unit is mapped to provide vehicle body simulation calculation; each vehicle body simulation unit constitutes the vehicle body to be simulated.

2. The vehicle body simulation method according to claim 1, characterized in that: Determining the mechanical property data of each first casting simulation unit based on the acquired casting simulation data includes: The mechanical property prediction data of each first casting simulation unit in the acquired casting simulation data is used as a data object to be clustered, and clustering processing is performed; Determine the mechanical property data of each first casting simulation unit; the mechanical property data of each first casting simulation unit is the mechanical property data of the cluster center of the cluster to which the current first casting simulation unit belongs, and the mechanical property data of each cluster center is determined based on the data objects constituting the cluster where the current cluster center is located.

3. The vehicle body simulation method according to claim 2, characterized in that: The mechanical property data of each cluster center is the mean value of each data object constituting the cluster where the current cluster center is located.

4. The vehicle body simulation method according to any one of claims 1 to 3, characterized in that: The step of generating a material constitutive curve group for each first casting simulation unit includes: performing the following steps on each first casting simulation unit: Determine a geometric transformation method; match a curve obtained by geometrically transforming a specified reference curve according to the geometric transformation method with the mechanical property data of the current first casting simulation unit, wherein the specified reference curve is a material constitutive curve corresponding to the specified strain rate in a reference material constitutive curve group; The respective curves in the reference material constitutive curve group are geometrically transformed according to the geometric transformation method to obtain the material constitutive curve group of the current first casting simulation unit.

5. The vehicle body simulation method according to claim 4, characterized in that: The material constitutive curve group of each vehicle body simulation unit is mapped based on the material constitutive curve group of each first casting simulation unit, including: Determine the data storage nodes of the material constitutive curve groups of the first casting simulation units as the first nodes, and form a first node set with the first nodes; Perform the following steps for each vehicle body simulation unit: Determine the data storage node of the current vehicle body simulation unit as the second node; Determine n1 first nodes around the second node from the first node set; wherein n1 is a preset positive integer; An interpolation calculation is performed on the material constitutive curve group of the determined n1 first nodes to obtain the material constitutive curve group of the current vehicle body simulation unit.

6. The vehicle body simulation method according to any one of claims 1 to 3, characterized in that: The casting simulation data of each vehicle body part also includes: casting residual stress prediction data of each second casting simulation unit constituting the current part, wherein the casting residual stress prediction data is obtained by casting deformation simulation; the method also includes: According to the casting residual stress prediction data of each second casting simulation unit, the casting residual stress data of each vehicle body simulation unit is mapped to obtain the casting residual stress data for performing the vehicle body simulation calculation.

7. The vehicle body simulation method according to claim 6, characterized in that: The method of mapping the casting residual stress data of each vehicle body simulation unit based on the casting residual stress prediction data of each second casting simulation unit includes: Determine the data storage nodes of the casting residual stress prediction data of each second casting simulation unit as the third node, and each third node constitutes a third node set; Perform the following steps for each vehicle body simulation unit: Determine the data storage node of the current vehicle body simulation unit as the second node; Determine n2 third nodes around the second node from the third node set; wherein n2 is a preset positive integer; Interpolation calculation is performed on the casting residual stress prediction data of the determined n2 third nodes to obtain the casting residual stress data of the current vehicle body simulation unit.

8. A vehicle body simulation device, characterized in that: include: a data acquisition unit, configured to acquire casting simulation data matching the mechanical test results of each body part; each body part is a part related to the body to be simulated, and the casting simulation data of each body part includes mechanical property prediction data of each first casting simulation unit constituting the current part at a specified strain rate, wherein the specified strain rate is a strain rate corresponding to the mechanical test results; A data processing unit, used to determine the mechanical property data of each first casting simulation unit according to the acquired casting simulation data, and generate a material constitutive curve group of each first casting simulation unit; The material constitutive curve corresponding to the specified strain rate in the material constitutive curve group of each first casting simulation unit matches the mechanical property data of the current first casting simulation unit; The data processing unit is also used to map the material constitutive curve group of each vehicle body simulation unit based on the material constitutive curve group of each first casting simulation unit for vehicle body simulation calculation; the vehicle body simulation units constitute the vehicle body to be simulated.

9. An electronic device, characterized in that: The method comprises at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs; The processor is used to execute the computer program so that the electronic device can implement the vehicle body simulation method as claimed in any one of claims 1 to 7.

10. A computer program product, characterized in that The method comprises computer-readable instructions, and when the computer-readable instructions are executed on an electronic device, the electronic device is enabled to implement the vehicle body simulation method as claimed in any one of claims 1 to 7.

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