Simulation method and simulation device for three-dimensional pressing rivet and storage medium

Abstract

The invention provides a three-dimensional pressing rivet simulation method and device and a storage medium. The simulation method comprises the steps that a finite element model and performance parameters are acquired; the three-dimensional pressing rivet simulation model is provided with a first area grid and a second area grid; establishing a local coordinate system in the second area grid, and coupling the boundary grid of the first area grid with the local coordinate system to obtain a finite element model; performing simulation calculation based on the finite element model and the performance parameters to obtain a pressing rivet simulation result; and performing analysis based on the press riveting simulation result to obtain a press riveting analysis result which is used for representing the performance of the three-dimensional press riveting simulation model. According to the method, the local coordinate system is established, and the boundary grid of the first area grid is coupled with the coordinate system, so that the motion state of the first area grid is kept consistent with that of the local coordinate system, and grid distortion caused by pulling the first area grid when the second area grid moves is avoided.

Description

Technical Field

[0001] The present application belongs to the field of computer technology, and specifically relates to a three-dimensional riveting simulation method, a simulation device and a storage medium. Background Art

[0002] The riveting process is a process that connects two or more metal materials of different stiffness together by riveting. In order to obtain a reliable riveting connection, it is necessary to reasonably design the relevant parameters such as the riveting parts, riveting tools, and riveting amount. The riveting process analysis is carried out using traditional riveting tests. The optimization cycle of parameters is long and the cost is high. Through simulation experiments, the analysis can be carried out quickly, and the mesh of the riveting model is generated to obtain a finite element model and calculate, which shortens the cycle and reduces the cost. When the Euler algorithm is used to simulate riveting, the common nodes of the Euler mesh and the Lagrangian mesh are prone to large distortion, which reduces the mesh quality, increases the calculation time, and affects the accuracy of the finite element analysis results.

[0003] Therefore, there is an urgent need for a riveting simulation method that can avoid mesh distortion. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a three-dimensional riveting simulation method, a simulation device and a storage medium.

[0005] On the one hand, the present application proposes a three-dimensional press riveting simulation method, the simulation method comprising:

[0006] Acquire a finite element model and performance parameters; the finite element model has a first region grid and a second region grid;

[0007] Establishing a local coordinate system in the second regional grid, coupling the first regional grid with the local coordinate system so that the motion state of the first regional grid is consistent with that of the local coordinate system, and obtaining a processed finite element model;

[0008] Perform simulation calculation based on the processed finite element model and the performance parameters to obtain a press riveting simulation result;

[0009] Perform analysis based on the press riveting simulation result to obtain a press riveting analysis result, wherein the press riveting analysis result is used to represent the performance of the finite element model;

[0010] Among them, the boundary grid of the first area grid and the boundary grid of the second area grid share nodes, the boundary grid of the first area grid and the boundary grid of the second area grid are both located at the riveting connection surface, the three-dimensional riveting simulation model includes riveting material and riveting components, and the riveting connection surface is the surface where the riveting material and the riveting component are extruded.

[0011] In some possible implementations, establishing a local coordinate system in the second regional grid includes:

[0012] Performing coordinate origin selection processing in the second regional grid to obtain a coordinate origin;

[0013] A three-dimensional local coordinate system is established based on the coordinate origin.

[0014] In some possible implementations, the three-dimensional riveting simulation model further includes a riveting tool, and the coordinate origin selection process is performed in the second area grid to obtain the coordinate origin, including:

[0015] Obtaining the central axis of the riveting tool in the riveting processing direction;

[0016] Obtaining a grid node located on the central axis in the second regional grid as a to-be-selected grid node; the grid node is an intersection point between grids in the second regional grid;

[0017] Determining the riveted connection surface as a reference surface;

[0018] Search is performed from the candidate grid nodes, and a candidate grid node that meets a distance condition is determined as a coordinate origin; the distance condition is a condition that a vertical distance from the candidate grid node to the reference plane is a preset distance.

[0019] In some possible implementations, obtaining a finite element model includes:

[0020] Obtain a three-dimensional riveting simulation model;

[0021] The three-dimensional press riveting simulation model is subjected to region division and mesh generation processing to obtain the three-dimensional press riveting simulation model.

[0022] In some possible implementations, the performing of region division and mesh generation processing on the three-dimensional pressure riveting simulation model includes:

[0023] Performing deformation prediction analysis on the three-dimensional pressure riveting simulation model to obtain a deformation degree prediction result;

[0024] Analyze the deformation degree prediction result, determine the area with a deformation degree greater than a preset deformation degree as a first area, and determine the area with a deformation degree less than the preset deformation degree as a second area;

[0025] The first region is subjected to an Euler mesh generation process to obtain the first region mesh, and the second region is subjected to a Lagrangian mesh generation process to obtain the second region mesh.

[0026] In some possible implementations, before obtaining the three-dimensional riveting simulation model and performance parameters, the simulation method further includes:

[0027] Performing material property testing on the pressure riveting material to obtain true stress and true strain of the pressure riveting material;

[0028] The performance parameters are analyzed and processed based on the true stress and the true strain to obtain the performance parameters, which are parameters representing the performance of the riveted material. The performance parameters include true stress-true strain value at yield time, true stress-true strain value at tensile strength time, and true stress-true strain value at necking fracture time.

[0029] In some possible implementations, after performing region division and mesh generation processing on the three-dimensional pressure riveting simulation model, the simulation method further includes:

[0030] A common node operation is performed on the first regional grid and the second regional grid to control the first regional grid and the second regional grid to transmit force and displacement through the common node; the common node is a grid node commonly used by the first regional grid and the second regional grid.

[0031] In some possible implementations, the simulation calculation is performed based on the processed finite element model and the performance parameters to obtain a press riveting simulation result, including:

[0032] Acquiring a contact relationship between the riveting material, the riveting component and the riveting tool;

[0033] Controlling the riveting tool to perform a simulated riveting operation based on a preset control method; the preset control method is a force control method or a displacement control method;

[0034] Perform simulation calculation on the finite element model based on the contact relationship, the preset control method and the performance parameters to obtain press riveting simulation result data;

[0035] The press riveting simulation result data is used to analyze and obtain press riveting analysis results, and the press riveting analysis results include stress results and deformation results.

[0036] On the other hand, an embodiment of the present application provides a three-dimensional riveting simulation device, the simulation device comprising:

[0037] An acquisition module, used to acquire a finite element model and performance parameters; the finite element model has a first area grid and a second area grid;

[0038] A coupling module, used for establishing a local coordinate system in the second regional grid, coupling the first regional grid with the local coordinate system, so that the motion state of the first regional grid and the local coordinate system are consistent, and obtaining a processed finite element model;

[0039] A calculation module, used for performing simulation calculation based on the processed finite element model and the performance parameters to obtain a press riveting simulation result;

[0040] An analysis module, used for performing analysis based on the press riveting simulation result to obtain a press riveting analysis result, wherein the press riveting analysis result is used to represent the performance of the three-dimensional press riveting simulation model;

[0041] Among them, the boundary grid of the first area grid and the boundary grid of the second area grid share nodes, the boundary grid of the first area grid and the boundary grid of the second area grid are both located at the riveting connection surface, the three-dimensional riveting simulation model includes riveting material and riveting components, and the riveting connection surface is the surface where the riveting material and the riveting component are extruded.

[0042] On the other hand, an embodiment of the present application provides a computer-readable storage medium. When instructions in the storage medium are executed by a processor of an electronic device, the electronic device can perform the simulation method as described above.

[0043] The technical solution of the present application has the following beneficial effects: by establishing a three-dimensional local coordinate system in the second area grid, the first area grid is coupled with the local coordinate system, thereby avoiding the first area grid being pulled to deform when the second area grid moves due to material deformation, avoiding the impact on the simulation calculation results, improving the accuracy of the simulation calculation results, and shortening the simulation calculation time. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 This is a process of a three-dimensional riveting simulation method provided in an embodiment of the present application. Figure 1 ;

[0046] Figure 2 This is a calculation result diagram of a press riveting simulation with mesh distortion provided in an embodiment of the present application;

[0047] Figure 3This is a three-dimensional pressure riveting simulation model diagram provided in an embodiment of the present application;

[0048] Figure 4 It is a three-dimensional riveting simulation model diagram with a local coordinate system provided in an embodiment of the present application;

[0049] Figure 5 This is a calculation result diagram of a press riveting simulation without mesh distortion provided in an embodiment of the present application;

[0050] Figure 6 It is a block diagram of a three-dimensional pressure riveting simulation device provided in an embodiment of the present application;

[0051] Figure 7 This is a hardware structure block diagram of a server provided in an embodiment of the present application.

[0052] The following is a supplementary description of the accompanying drawings:

[0053] 1-Riveting material;

[0054] 2-Pressure riveting parts;

[0055] 3-Riveting tool;

[0056] 4- Local coordinate system. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions 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 making creative work are within the scope of protection of this application.

[0058] It should be noted that the terms "first", "second", etc. in the specification and claims of the embodiment 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 interchanged where appropriate, so that the embodiments of the embodiment of the present application described here can be implemented in an order other than those illustrated or described here. Thus, the features defined as "first" and "second" can expressly or implicitly include one or more of the features. In the description of the present embodiment, unless otherwise specified, the meaning of "multiple" is two or more. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or server comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0059] In order to make the purpose, technical solution and advantages disclosed in the embodiments of the present application more clearly understood, the embodiments of the present application are further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present application and are not used to limit the embodiments of the present application.

[0060] In order to facilitate understanding of the above-mentioned technical solutions and the technical effects produced by the embodiments of the present application, the embodiments of the present application first explain the relevant professional terms:

[0061] Euler mesh: A type of mesh widely used in fields such as fluid dynamics and aerodynamics. The Euler mesh is a mesh fixed in space, and the node positions of the mesh do not change during the solution process.

[0062] Lagrangian mesh: Lagrangian mesh is a common mesh type used in finite element analysis, and the mesh position moves with the material.

[0063] In the three-dimensional riveting simulation model, the riveted material and the riveted parts share nodes at the junction. Combined with the above characteristics, during the riveting simulation process, when the riveting force is large, the riveted material and the riveted parts will be deformed, causing the Lagrangian grid to move, and then the Euler grid that shares nodes with the Lagrangian grid will be pulled and severely distorted, resulting in a decrease in the incremental step time during the analysis process, and the total time to complete the analysis increases exponentially, resulting in a decrease in the accuracy of the calculation results, or even the inability to complete the calculation process.

[0064] In order to solve the above technical problems, the present invention provides a three-dimensional riveting simulation method, a simulation device and a storage medium, which can avoid mesh distortion and ensure the accuracy of analysis results.

[0065] See also Figure 1 , this specification provides method operation steps as described in the embodiments or flowcharts, but may include more or fewer operation steps based on conventional or non-creative labor. The order of steps listed in the embodiments is only one way of executing the steps among many orders, and does not represent the only order of execution. When the actual system or server product is executed, it can be executed in sequence or in parallel (for example, in a parallel processor or multi-threaded processing environment) according to the method shown in the embodiments or drawings. On the one hand, the present application proposes a simulation method for three-dimensional riveting, specifically as follows Figure 1 As shown, the simulation method may include:

[0066] S101: Obtain finite element model and performance parameters.

[0067] Optionally, the finite element model has a first area mesh and a second area mesh. In view of the different deformation degrees of different areas in the finite element model, different types of meshes are generated in different areas to facilitate calculation and reduce the influence of material deformation on calculation accuracy. The first area mesh is a mesh area with a larger deformation degree, and the second area mesh is a mesh area with a smaller deformation degree.

[0068] S103: establishing a local coordinate system in the second regional grid, coupling the first regional grid with the local coordinate system so that the motion states of the first regional grid and the local coordinate system are consistent, and obtaining a processed finite element model.

[0069] See also Figure 2 , Figure 2 It is a calculation result diagram of a riveting simulation with grid distortion provided by an embodiment of the present application. Optionally, the local coordinate system 4 is established with reference to the second regional grid, so the motion state of the local coordinate system 4 is associated with the motion state of the second regional grid. Coupling the first regional grid with the local coordinate system 4 means fixing the position of the first regional grid in the local coordinate system 4 so that the first regional grid and the local coordinate system 4 are relatively stationary. Since the local coordinate system 4 moves with the second regional grid, the positions of the grid nodes in the first regional grid in the local coordinate system 4 have been fixed, and the first regional grid needs to move with the local coordinate system 4 as a whole, that is, the first regional grid moves with the second regional grid as a whole, to avoid relative movement between the first regional grid and the second regional grid, which can avoid the following. Figure 2 Mesh distortion shown.

[0070] S105: Perform simulation calculation based on the processed finite element model and the performance parameters to obtain a riveting simulation result.

[0071] Optionally, the finite element model is a model established when using the finite element analysis method. It is a group of unit combinations that are connected only at nodes, transmit forces only at nodes, and are constrained only at nodes. It is used to analyze the force and deformation caused by the riveting process. The riveting process is the process of pressing the riveting material 1 into the riveting component 2. During this process, the riveting material 1 and the riveting component 2 are squeezed and deformed to varying degrees. Simulation calculation refers to the process of calculating the force and deformation of the model after setting parameters and other conditions for the model.

[0072] S107: Analyze based on the press riveting simulation result to obtain a press riveting analysis result.

[0073] Optionally, the riveting analysis results are used to represent the performance of the finite element model; wherein the boundary mesh of the first area mesh and the boundary mesh of the second area mesh share nodes, the boundary mesh of the first area mesh and the boundary mesh of the second area mesh are both located on the riveting connection surface, the three-dimensional riveting simulation model includes a riveting material 1 and a riveting component 2, and the riveting connection surface is the surface where the riveting material 1 and the riveting component 2 are extruded.

[0074] It should be noted that the first area grid and the second area grid are in the riveted material 1 and the riveted component 2. Optionally, the common node referred to in this specification means that the boundary grid of the first area grid and the boundary grid of the second area grid have common grid nodes, and force and displacement are transmitted through the commonly used grid nodes.

[0075] The embodiment of the present invention establishes a three-dimensional local coordinate system in the second area grid and couples the first area grid with the local coordinate system, thereby preventing the first area grid from being deformed when the second area grid moves due to material deformation, avoiding the impact on the simulation calculation results, improving the accuracy of the simulation calculation results, and shortening the simulation calculation time.

[0076] See also Figure 3 , Figure 4 , Figure 3 This is a three-dimensional pressure riveting simulation model diagram provided in an embodiment of the present application. Figure 4 is a three-dimensional riveting simulation model diagram with a local coordinate system provided in an embodiment of the present application; in some possible embodiments, the establishing of the local coordinate system in the second area grid includes:

[0077] A coordinate origin selection process is performed in the second area grid to obtain a coordinate origin.

[0078] Optionally, the coordinate origin is used to determine the position of the local coordinate system 4. A three-dimensional local coordinate system 4 can be established based on the coordinate origin. The coordinate origin should be one of the grid nodes of the second regional grid.

[0079] A three-dimensional local coordinate system 4 is established based on the coordinate origin.

[0080] The embodiment of the present invention establishes a three-dimensional local coordinate system 4 in the second area grid to synchronize the motion states of the first area grid and the second area grid, thereby preventing the first area grid from being deformed when the second area grid moves due to material deformation, avoiding the impact on the simulation calculation results, improving the accuracy of the simulation calculation results, and shortening the simulation calculation time.

[0081] In some possible embodiments, the three-dimensional riveting simulation model further includes a riveting tool 3, and the coordinate origin selection process is performed in the second area grid to obtain the coordinate origin, including:

[0082] The central axis of the riveting tool in the riveting processing direction is obtained.

[0083] Optionally, the riveting processing direction refers to the direction in which the riveting material 1 is pressed into the riveting component 2 , and the central axis refers to the central axis of the riveting tool 3 .

[0084] Optionally, the three-dimensional model is imported into CAE software for finite element modeling, and a local coordinate system 4 is created with the central axis of the Euler grid, and the center point of the local coordinate system 4 needs to be located on the Lagrange grid node. Exemplarily, the keyword *alereferencesystemnodes is used to set it in the CAR software, and then the Euler grid is coupled to the local coordinate system 4 and set it by the keyword *alereferencesystemgroups.

[0085] A grid node located on the central axis in the second regional grid is obtained as a grid node to be selected.

[0086] Optionally, the grid node is an intersection point between grids in the second region grid; it should be noted that there is a hollow area for accommodating the riveting material 1 on the riveting component 2 where the second region grid is located, and there is no grid in the hollow area.

[0087] The riveted connection surface is determined as a reference surface.

[0088] Optionally, a search is performed from the candidate grid nodes to determine a candidate grid node that meets a distance condition as the coordinate origin. The distance condition is a condition that a vertical distance from the candidate grid node to the reference plane is a preset distance.

[0089] Optionally, since the upper half of the riveted component 2 given in the embodiment is hollow, there is no second regional grid in the hollow part, and the condition for establishing the coordinate origin is not met. It is necessary to establish a local coordinate system 4 in the solid area of ​​the riveted component 2. The central axis is hollow within a preset distance from the reference surface, and there is no Lagrangian grid, so the local coordinate system 4 is to be established at a distance greater than the preset distance.

[0090] The embodiment of the present invention establishes a local coordinate system to couple the motion state of the Euler grid with the motion state of the Lagrangian grid, so that the entire Euler grid moves with the movement of the Lagrangian grid, avoiding grid distortion of the Euler grid and solving the grid distortion problem.

[0091] In some possible embodiments, obtaining a finite element model includes:

[0092] Get the 3D riveting simulation model.

[0093] Optionally, the three-dimensional riveting simulation model is established according to the actual riveting process requirements, including the three-dimensional models of aluminum alloy, one-way valve and riveting tool 3. It is necessary to perform three-dimensional modeling in CAD software and set the parameters. For example, the one-way valve and riveting tool 3 are set as Mat1 elastic material, and the single-point reduced integration algorithm is adopted. The aluminum alloy is set as Mat24 multilinear elastic-plastic material, and the Euler grid adopts the single-point integral single material or empty material algorithm. The single material is the initial aluminum alloy area, and the empty material is the pre-filled area. The Lagrangian grid adopts the single-point tetrahedral grid algorithm, and the tetrahedral grid is used for the meshing of complex geometric models.

[0094] The three-dimensional pressure riveting simulation model is subjected to region division and mesh generation processing to obtain a finite element model.

[0095] It should be noted that before performing simulation calculations, the established three-dimensional press riveting simulation model needs to be processed to obtain a finite element model, the three-dimensional press riveting simulation model is divided into a first area and a second area, and meshes are generated respectively to obtain a finite element model.

[0096] Optionally, the three-dimensional model is imported into CAE software for finite element modeling, and a regular body is established in the possible large deformation area of ​​the riveted component 2 as the Euler mesh area of ​​the finite element model, and the small deformation area of ​​the riveted material 1 is set to the Lagrangian unit algorithm, and the Euler domain mesh is set to the Euler mesh algorithm.

[0097] The embodiment of the present invention obtains a finite element model by dividing the established three-dimensional riveting simulation model into regions and generating a grid, so that the processed finite element model is connected through grid nodes, only relies on the grid to transmit force, and is only constrained at the grid nodes, which is convenient for simulation calculations, improves calculation efficiency, and thus improves the efficiency of riveting result analysis.

[0098] In some possible embodiments, the performing of region division and mesh generation processing on the three-dimensional pressure riveting simulation model includes:

[0099] A deformation prediction analysis is performed on the three-dimensional pressure riveting simulation model to obtain a deformation degree prediction result.

[0100] Optionally, the deformation prediction analysis refers to an analysis based on mechanical knowledge, and the deformation degree prediction result refers to a prediction result of the deformation degree of the riveting material 1, the riveting component 2, and the riveting tool 3 in the three-dimensional riveting simulation model. The deformation degree prediction result is analyzed, and a region with a deformation degree greater than a preset deformation degree is determined as a first region, and a region with a deformation degree less than the preset deformation degree is determined as a second region.

[0101] Optionally, the preset deformation degree is a preset physical quantity for evaluating the deformation degree, which may be a grid node offset. The grid node offset refers to the offset distance of the grid node after riveting treatment relative to before treatment. The deformation degree of the first area is greater than that of the second area.

[0102] The first region is subjected to an Euler mesh generation process to obtain the first region mesh, and the second region is subjected to a Lagrangian mesh generation process to obtain the second region mesh.

[0103] Optionally, since the Euler mesh has the characteristic of not moving with material deformation, the Euler mesh generation processing is performed on the first area with a larger deformation degree, and the Lagrangian mesh generation processing is performed on the second area with a smaller deformation degree. The mesh generation processing refers to the generation processing by setting the corresponding algorithm through the mesh division software, such as the Euler mesh algorithm.

[0104] The embodiment of the present invention predicts the deformation degree of each part of the three-dimensional simulation model, sets different grids according to the deformation degree of each part, so that the obtained finite element model has different types of grids, avoids the material deformation causing the calculation process to be too time-consuming or even calculation errors, or the inability to complete the calculation, thereby ensuring the calculation efficiency and the correctness of the results obtained by the finite element calculation.

[0105] In some possible embodiments, before obtaining the three-dimensional riveting simulation model and performance parameters, the simulation method further includes:

[0106] The material properties of the pressure riveting material are tested to obtain the true stress and true strain of the pressure riveting material.

[0107] It should be noted that the simulation calculation needs to be combined with the performance parameters of the pressure riveting material 1 to accurately analyze the deformation of the model. Therefore, before establishing the three-dimensional pressure riveting simulation model, the performance parameters are obtained first. Optionally, the pressure riveting material 1 is tested for aluminum alloy material performance in accordance with "GB / T 228.1 Metallic Material Tensile Test Part 1: Room Temperature Test Method", and then the obtained engineering stress-strain is converted into true stress-true strain, and the true stress-true strain values ​​of the pressure riveting material 1 at the yield moment, tensile strength moment, and necking fracture moment are obtained respectively as the performance parameters of the pressure riveting material 1 for simulation calculation.

[0108] For the performance parameters of the riveting material 1, it is necessary to conduct material performance tests in accordance with "GB / T 228.1 Tensile test of metallic materials Part 1: Room temperature test method" to obtain data such as the material's yield strength, tensile strength, elongation at break, and cross-sectional shrinkage.

[0109] The present invention is achieved through the following technical solutions:

[0110] Step 1: Material performance test shall be conducted in accordance with GB / T 228.1 Metallic Material Tensile Test Part 1: Room Temperature Test Method to obtain data such as yield strength, tensile strength, elongation at break and cross-sectional shrinkage. According to the principle of approximately constant volume in the plastic deformation stage:

[0111] A i L i =AL

[0112] Available

[0113]

[0114] Thus, the true stress-true strain relationship is established

[0115]

[0116] Where:

[0117] A: The cross-sectional area of ​​the sample at the current moment

[0118] Ai: The original cross-sectional area of ​​the sample at time i

[0119] L: Current length of the specimen

[0120] Li: original length of the sample at time i

[0121] σ: Engineering stress

[0122] True stress

[0123] ε: Engineering strain

[0124] True strain

[0125] Before the tensile specimen is necked, the true strain can be determined according to the length change. After necking, due to the large local deformation, the true strain needs to be determined according to the cross-sectional area of ​​the necking position. Thus, the true stress-true strain value at the yield moment, tensile strength moment, and necking fracture moment is determined as the performance parameter of the riveting material 1.

[0126] The performance parameters are analyzed and processed based on the true stress and the true strain to obtain the performance parameters, which are parameters representing the performance of the riveted material. The performance parameters include true stress-true strain value at yield time, true stress-true strain value at tensile strength time, and true stress-true strain value at necking fracture time.

[0127] By setting the local coordinate system 4 and other steps, the Euler mesh can be prevented from being deformed, such as Figure 4 Specifically, the simulation results are analyzed by post-processing software, and the analysis results may include the stress condition, the deformation condition of the riveted material 1, etc. For the Euler mesh area, the fluid material display condition may be set.

[0128] The embodiment of the present invention performs a performance test on the press riveting material before establishing the three-dimensional press riveting simulation model to obtain the performance parameters of the press riveting material, and simulates the three-dimensional press riveting simulation model using the press riveting material based on the performance parameters, thereby ensuring the accuracy of the simulation calculation, facilitating accurate adjustment of the press riveting parameters, and optimizing the actual effect of the press riveting process.

[0129] In some possible embodiments, after performing area division and mesh generation processing on the three-dimensional pressure riveting simulation model, the simulation method further includes:

[0130] A common node operation is performed on the first area grid and the second area grid to control the first area grid and the second area grid to transmit force and displacement through the common node.

[0131] Optionally, the common node operation refers to making the first regional mesh and the second regional mesh located on the riveted connection surface have a common mesh node, and the common node is a mesh node commonly used by the first regional mesh and the second regional mesh.

[0132] The embodiment of the present invention performs a common node operation on the first area grid and the second area grid, and can transmit force and displacement through the common node, so that the first area grid and the second area grid located on the riveting connection surface can have the same force change and displacement change, thereby improving the consistency of force and displacement transmission, making the simulation closer to the real riveting environment, and enhancing the authenticity of the simulation situation, thereby improving the accuracy of the simulation calculation and enhancing the correctness of the optimization direction of the riveting parameters.

[0133] In some possible embodiments, the simulation calculation is performed based on the processed finite element model and the performance parameters to obtain a riveting simulation result, including:

[0134] The contact relationship among the riveting material, the riveting component and the riveting tool is obtained.

[0135] Optionally, the contact relationship between the riveting material 1, the riveting component 2 and the riveting tool 3 is an important factor affecting the deformation degree of the riveting model. For example, the contact relationship can be reflected in the relative position between the riveting tool 3 and the riveting material 1, the riveting component 2, etc.

[0136] The riveting tool is controlled to perform a simulated riveting operation based on a preset control method.

[0137] Optionally, the preset control method is a force control method or a displacement control method, and a load is applied to the riveting tool 3 according to the force control method or displacement control method of the riveting process. For example, the load applied to the riveting material 1 by the riveting tool 3 is set to 500N, or the displacement of the riveting tool 3 to the riveting material 1 is set to 2cm. Exemplarily, a force control press is used for riveting, a force load is applied to the riveting tool 3, and the *CONSTRAINED_LAGRANGE_IN_SOLID keyword is used for setting, and the *control_ALE keyword is set for Euler-Lagrangian calculation transmission setting, and the ls-dyna solver is used for solving after the setting.

[0138] The finite element model is simulated and calculated based on the contact relationship, the preset control method and the performance parameters to obtain press riveting simulation result data.

[0139] Optionally, the press riveting simulation result data is used to analyze and obtain press riveting analysis results, and the press riveting analysis results include stress results and deformation results.

[0140] See also Figure 2 and Figure 5 , Figure 2 The results of the simulation analysis without using the local coordinate system 4 are shown. Figure 5 The results of the simulation analysis using the local coordinate system 4 are shown. Figure 2 As shown in , due to the movement of the Lagrangian grid in the second region, the grid in the dashed box that shares the same nodes with the Lagrangian grid and is located on the riveted connection surface is deformed, as shown in Figure 5 As shown in the figure, the mesh in the dashed box that shares nodes with the Lagrangian mesh and is located on the riveted connection surface does not deform, which effectively solves the problem of mesh distortion.

[0141] The embodiment of the present invention obtains the riveting simulation result by setting relevant conditions in the finite element model and performing calculations under the conditions. Since a local coordinate system is set in the finite element model, the mesh of the first area is not distorted, which ensures the accuracy of the simulation calculation, is conducive to accurately adjusting the riveting parameters, and optimizing the actual effect of the riveting process.

[0142] Implementing the embodiments of the present invention has the following beneficial effects:

[0143] 1. The embodiment of the present invention establishes a three-dimensional local coordinate system in the second area grid and couples the first area grid with the local coordinate system, thereby preventing the first area grid from being deformed when the second area grid moves due to material deformation, avoiding the impact on the simulation calculation results, improving the accuracy of the simulation calculation results, and shortening the simulation calculation time.

[0144] 2. The embodiment of the present invention establishes a three-dimensional local coordinate system in the second area grid to synchronize the motion states of the first area grid and the second area grid, thereby preventing the first area grid from being deformed when the second area grid moves due to material deformation, thereby avoiding the impact on the simulation calculation results, improving the accuracy of the simulation calculation results, and shortening the simulation calculation time.

[0145] 3. The embodiment of the present invention establishes a local coordinate system to couple the motion state of the Euler grid with the motion state of the Lagrangian grid, so that the Euler grid as a whole moves with the movement of the Lagrangian grid, avoiding grid distortion of the Euler grid and solving the grid distortion problem.

[0146] 4. The embodiment of the present invention obtains a finite element model by dividing the established three-dimensional riveting simulation model into regions and generating a grid, so that the processed finite element model is connected through grid nodes, only relies on the grid to transmit force, and is only constrained at the grid nodes, which facilitates simulation calculations, improves calculation efficiency, and thus improves the efficiency of riveting result analysis.

[0147] 5. The embodiment of the present invention predicts the deformation degree of each part of the three-dimensional simulation model, sets different grids according to the deformation degree of each part, so that the obtained finite element model has different types of grids, thereby avoiding the material deformation causing the calculation process to be too time-consuming or even calculation errors, or the inability to complete the calculation, thereby ensuring the calculation efficiency and the correctness of the results obtained by the finite element calculation.

[0148] 6. The embodiment of the present invention performs a performance test on the press riveting material before establishing the three-dimensional press riveting simulation model to obtain the performance parameters of the press riveting material, and simulates the three-dimensional press riveting simulation model using the press riveting material based on the performance parameters, thereby ensuring the accuracy of the simulation calculation, facilitating accurate adjustment of the press riveting parameters, and optimizing the actual effect of the press riveting process.

[0149] 7. The embodiment of the present invention can transmit force and displacement through the common node by performing a common node operation on the first area grid and the second area grid, so that the first area grid and the second area grid located on the riveting connection surface can have the same force change and displacement change, thereby improving the consistency of force and displacement transmission, making the simulation closer to the real riveting environment, and enhancing the authenticity of the simulation situation, thereby improving the accuracy of the simulation calculation and enhancing the correctness of the optimization direction of the riveting parameters.

[0150] 8. The embodiment of the present invention obtains the riveting simulation result by setting relevant conditions in the finite element model and performing calculations under the conditions. Since a local coordinate system is set in the finite element model, the mesh of the first area is not distorted, which ensures the accuracy of the simulation calculation, is conducive to accurately adjusting the riveting parameters, and optimizing the actual effect of the riveting process.

[0151] On the other hand, see Figure 6 As shown in the figure, the embodiment of the present application provides a three-dimensional riveting simulation device, and the simulation device includes:

[0152] An acquisition module 201 is used to acquire a finite element model and performance parameters; the finite element model has a first region grid and a second region grid;

[0153] A coupling module 203 is used to establish a local coordinate system in the second regional grid, and couple the first regional grid with the local coordinate system so that the motion state of the first regional grid is consistent with that of the local coordinate system, thereby obtaining a processed finite element model;

[0154] A calculation module 205 is used to perform simulation calculation based on the processed finite element model and the performance parameters to obtain a press riveting simulation result;

[0155] An analysis module 207, used to perform analysis based on the press riveting simulation result to obtain a press riveting analysis result, wherein the press riveting analysis result is used to represent the performance of the three-dimensional press riveting simulation model;

[0156] Among them, the boundary grid of the first area grid and the boundary grid of the second area grid share nodes, the boundary grid of the first area grid and the boundary grid of the second area grid are both located at the riveting connection surface, the three-dimensional riveting simulation model includes riveting material and riveting components, and the riveting connection surface is the surface where the riveting material and the riveting component are extruded.

[0157] In some embodiments, the coupling module comprises:

[0158] An origin selection module, used for performing a coordinate origin selection process in the second area grid to obtain a coordinate origin;

[0159] The coordinate system establishing module is used to establish a three-dimensional local coordinate system based on the coordinate origin.

[0160] In some embodiments, the origin selection module includes:

[0161] A central axis acquisition unit, used to acquire the central axis of the riveting tool in the riveting processing direction;

[0162] A grid node acquisition unit, used to acquire a grid node located on the central axis in the second regional grid as a grid node to be selected; the grid node is an intersection point between grids in the second regional grid;

[0163] A reference surface determination unit, used to determine the riveting connection surface as a reference surface;

[0164] The coordinate origin determination unit is used to search from the candidate grid nodes and determine the candidate grid node that meets the distance condition as the coordinate origin; the distance condition is that the vertical distance from the candidate grid node to the reference surface is a preset distance.

[0165] In some embodiments, the acquisition module includes:

[0166] A parameter acquisition unit, used to acquire a three-dimensional pressure riveting simulation model;

[0167] The mesh generation unit is used to perform area division and mesh generation processing on the three-dimensional pressure riveting simulation model to obtain the finite element model.

[0168] In some embodiments, the grid generation unit comprises:

[0169] A deformation prediction subunit is used to perform deformation prediction analysis on the three-dimensional pressure riveting simulation model to obtain a deformation degree prediction result;

[0170] A deformation analysis subunit, used to analyze the deformation degree prediction result, determine the area with a deformation degree greater than a preset deformation degree as the first area, and determine the area with a deformation degree less than the preset deformation degree as the second area;

[0171] The grid generation subunit is used to perform an Euler grid generation process on the first area to obtain the first area grid, and to perform a Lagrangian grid generation process on the second area to obtain the second area grid.

[0172] In some embodiments, the simulation device further comprises:

[0173] A performance testing module, used to perform material performance testing on the pressure riveting material to obtain the true stress and true strain of the pressure riveting material;

[0174] A performance analysis module is used to perform performance parameter analysis based on the true stress and the true strain to obtain the performance parameters, wherein the performance parameters are parameters representing the performance of the riveted material, and the performance parameters include true stress-true strain value at yield time, true stress-true strain value at tensile strength time, and true stress-true strain value at necking fracture time.

[0175] In some embodiments, the simulation device further comprises:

[0176] A node processing module is used to perform a common node operation on the first regional grid and the second regional grid to control the first regional grid and the second regional grid to transmit force and displacement through the common node; the common node is a grid node commonly used by the first regional grid and the second regional grid.

[0177] In some embodiments, the computing module comprises:

[0178] A relationship determination unit, used for obtaining a contact relationship between the pressure riveting material, the pressure riveting component and the pressure riveting tool;

[0179] A simulation unit, used for controlling the riveting tool to perform a simulated riveting operation based on a preset control method; the preset control method is a force control method or a displacement control method;

[0180] A calculation unit, used to perform simulation calculation on the finite element model based on the contact relationship, the preset control method and the performance parameters to obtain press riveting simulation result data;

[0181] The press riveting simulation result data is used to analyze and obtain press riveting analysis results, and the press riveting analysis results include stress results and deformation results.

[0182] It should be noted that the device embodiment provided in the embodiments of the present application and the above-mentioned method embodiment are based on the same inventive concept.

[0183] An embodiment of the present application further provides a computer-readable storage medium. When instructions in the storage medium are executed by a processor of an electronic device, the electronic device is enabled to perform the simulation method as described above.

[0184] Optionally, in the embodiment of this specification, the storage medium may be located in at least one of the multiple network servers of the computer network. Optionally, in this embodiment, the above storage medium may include but is not limited to: a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and other media that can store program codes.

[0185] The memory of the embodiment of this specification can be used to store software programs and modules, and the processor executes various functional applications and data processing by running the software programs and modules stored in the memory. The memory may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, applications required for functions, etc.; the data storage area may store data created according to the use of the device, etc. In addition, the memory 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 device. Accordingly, the memory may also include a memory controller to provide the processor with access to the memory.

[0186] The method embodiments provided in the embodiments of the present application can be executed in a terminal, a computer terminal, a server or a similar computing device. Taking running on a server as an example, Figure 7 is a hardware structure block diagram of a server provided in an embodiment of the present application. Figure 7 As shown, the server 300 may have relatively large differences due to different configurations or performances, and may include one or more central processing units (CPU) 310 (the central processing unit 310 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory 330 for storing data, and one or more storage media 320 (such as one or more mass storage devices) for storing application programs 323 or data 322. Among them, the memory 330 and the storage medium 320 can be short-term storage or permanent storage. The program stored in the storage medium 320 may include one or more modules, each of which may include a series of instruction operations on the server. Furthermore, the central processing unit 310 can be configured to communicate with the storage medium 320 and execute a series of instruction operations in the storage medium 320 on the server 300. The server 300 may also include one or more power supplies 360, one or more wired or wireless network interfaces 350, one or more input and output interfaces 340, and / or one or more operating systems 321, such as Windows ServerTM, Mac OS XTM, UnixTM, LinuxTM, FreeBSDTM, etc.

[0187] The input / output interface 340 may be used to receive or send data via a network. The specific example of the network may include a wireless network provided by a communication provider of the server 300. In one example, the input / output interface 340 includes a network adapter (Network Interface Controller, NIC), which may be connected to other network devices via a base station so as to communicate with the Internet. In one example, the input / output interface 340 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0188] It can be understood by those skilled in the art that Figure 7 The structure shown is only for illustration and does not limit the structure of the above electronic device. Figure 7 More or fewer components as shown, or with Figure 7 Different configurations are shown.

[0189] It should be noted that the above-mentioned sequence of the embodiments of the present application is for description only and does not represent the advantages and disadvantages of the embodiments. The above-mentioned specific embodiments of this specification are described. Other embodiments are within the scope of the attached claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0190] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device and server embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0191] A person skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or by a program to instruct the relevant hardware, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk or an optical disk, etc.

[0192] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A three-dimensional riveting simulation method, characterized in that: The simulation method comprises: Acquire a finite element model and performance parameters; the finite element model has a first region grid and a second region grid; Establishing a local coordinate system in the second regional grid, coupling the first regional grid with the local coordinate system so that the motion state of the first regional grid is consistent with that of the local coordinate system, and obtaining a processed finite element model; Perform simulation calculation based on the processed finite element model and the performance parameters to obtain a press riveting simulation result; Perform analysis based on the press riveting simulation result to obtain a press riveting analysis result, wherein the press riveting analysis result is used to represent the performance of the three-dimensional press riveting simulation model; Among them, the boundary grid of the first area grid and the boundary grid of the second area grid share nodes, the boundary grid of the first area grid and the boundary grid of the second area grid are both located at the riveting connection surface, the three-dimensional riveting simulation model includes riveting material and riveting components, and the riveting connection surface is the surface where the riveting material and the riveting component are extruded.

2. The simulation method according to claim 1, characterized in that: The establishing of a local coordinate system in the second regional grid includes: Performing coordinate origin selection processing in the second regional grid to obtain a coordinate origin; A three-dimensional local coordinate system is established based on the coordinate origin.

3. The simulation method according to claim 2, characterized in that: The three-dimensional riveting simulation model also includes a riveting tool, and the coordinate origin selection process is performed in the second area grid to obtain the coordinate origin, including: Obtaining the central axis of the riveting tool in the riveting processing direction; Obtaining a grid node located on the central axis in the second regional grid as a to-be-selected grid node; the grid node is an intersection point between grids in the second regional grid; Determining the riveted connection surface as a reference surface; Search is performed from the candidate grid nodes, and a candidate grid node that meets a distance condition is determined as a coordinate origin; the distance condition is a condition that a vertical distance from the candidate grid node to the reference plane is a preset distance.

4. The simulation method according to claim 3, characterized in that: The obtaining of the finite element model comprises: Obtain a three-dimensional riveting simulation model; The three-dimensional riveting simulation model is subjected to region division and mesh generation processing to obtain the finite element model.

5. The simulation method according to claim 4, characterized in that: The region division and mesh generation processing of the three-dimensional pressure riveting simulation model includes: Performing deformation prediction analysis on the three-dimensional pressure riveting simulation model to obtain a deformation degree prediction result; Analyze the deformation degree prediction result, determine the area with a deformation degree greater than a preset deformation degree as a first area, and determine the area with a deformation degree less than the preset deformation degree as a second area; The first region is subjected to an Euler mesh generation process to obtain the first region mesh, and the second region is subjected to a Lagrangian mesh generation process to obtain the second region mesh.

6. The simulation method according to claim 4, characterized in that: Before obtaining the finite element model and the performance parameters, the simulation method further includes: Performing material property testing on the pressure riveting material to obtain true stress and true strain of the pressure riveting material; The performance parameters are analyzed and processed based on the true stress and the true strain to obtain the performance parameters, which are parameters representing the performance of the riveted material. The performance parameters include true stress-true strain value at yield time, true stress-true strain value at tensile strength time, and true stress-true strain value at necking fracture time.

7. The simulation method according to claim 4, characterized in that: After the three-dimensional pressure riveting simulation model is divided into regions and a mesh is generated, the simulation method further includes: A common node operation is performed on the first regional grid and the second regional grid to control the first regional grid and the second regional grid to transmit force and displacement through the common node; the common node is a grid node commonly used by the first regional grid and the second regional grid.

8. The simulation method according to claim 5, characterized in that: The simulation calculation is performed based on the processed finite element model and the performance parameters to obtain the riveting simulation result, including: Acquiring a contact relationship between the riveting material, the riveting component and the riveting tool; Controlling the riveting tool to perform a simulated riveting operation based on a preset control method; the preset control method is a force control method or a displacement control method; Perform simulation calculation on the finite element model based on the contact relationship, the preset control method and the performance parameters to obtain press riveting simulation result data; The press riveting simulation result data is used to analyze and obtain press riveting analysis results, and the press riveting analysis results include stress results and deformation results.

9. A three-dimensional riveting simulation device, characterized in that: The simulation device comprises: An acquisition module, used to acquire a finite element model and performance parameters; the finite element model has a first area grid and a second area grid; A coupling module, used for establishing a local coordinate system in the second regional grid, coupling the first regional grid with the local coordinate system, so that the motion state of the first regional grid and the local coordinate system are consistent, and obtaining a processed finite element model; A calculation module, used for performing simulation calculation based on the processed finite element model and the performance parameters to obtain a press riveting simulation result; An analysis module, used for performing analysis based on the press riveting simulation result to obtain a press riveting analysis result, wherein the press riveting analysis result is used to represent the performance of the finite element model; Among them, the boundary grid of the first area grid and the boundary grid of the second area grid share nodes, the boundary grid of the first area grid and the boundary grid of the second area grid are both located at the riveted connection surface, the finite element model includes a riveted material and a riveted component, and the riveted connection surface is the surface where the riveted material and the riveted component are extruded.

10. A computer-readable storage medium, characterized in that: When the instructions in the storage medium are executed by a processor of an electronic device, the electronic device is enabled to execute the simulation method as claimed in any one of claims 1 to 8.

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