A transient simulation method of vehicle strength based on actual road surface

Abstract

The present invention relates to a method for transient simulation of vehicle strength based on actual road surface, comprising the following steps: establishing a three-dimensional model of a whole vehicle; meshing the three-dimensional model of the whole vehicle; connecting the parts with connection relationship in the three-dimensional model of the whole vehicle, and setting the material parameters of each part of the three-dimensional model of the whole vehicle; establishing a three-dimensional model of the road surface; meshing the three-dimensional model of the road surface, and setting the material parameters of the three-dimensional model of the road surface; assembling the three-dimensional model of the whole vehicle and the three-dimensional model of the road surface together to form a whole vehicle and road surface assembly model; setting boundary conditions and applying constraints to the whole vehicle and road surface assembly model; performing transient calculation of vehicle strength; and reading the transient calculation results of vehicle strength. The present invention can perform transient simulation of strength at the whole vehicle level in the development stage, thereby discovering potential problems, and can also perform weight reduction optimization in places with abundant design margins, thereby shortening the development cycle of the whole vehicle and improving the economic indicators of vehicle structural design.

Description

Technical Field

[0001] The present invention relates to whole vehicle strength simulation, and in particular to a transient simulation method of vehicle strength based on actual road conditions. Background Art

[0002] Vehicle strength directly impacts driving safety. Automotive finite element model simulation is a crucial tool for design verification during the design phase. A complete and accurate finite element model can predict design risks. Furthermore, precise simulation results can be used to optimize vehicle weight reduction and improve the economic efficiency of vehicle structural design.

[0003] The patent application with publication number CN201710368211.4 discloses a CAE-based automobile ball joint structure design method. It addresses the problems existing in the existing technology and provides a CAE-based automobile ball joint structure design method, which can effectively shorten the development cycle of automobile ball joint structure design.

[0004] However, this patent is only a simulation method for automotive parts, not a transient simulation at the vehicle level. It cannot simulate the mutual influence between parts and between systems, cannot simulate the entire vehicle, and cannot shorten the development cycle of the vehicle. Summary of the Invention

[0005] The purpose of the present invention is to propose a method for transient simulation of vehicle strength on actual roads, so as to realize transient simulation of vehicle strength at the development stage.

[0006] The present invention provides a method for simulating the transient strength of vehicles on actual roads, comprising the following steps:

[0007] S1. Build a three-dimensional model of the vehicle;

[0008] S2, meshing the three-dimensional model of the vehicle established in S1;

[0009] S3. Connect the components that have a connection relationship in the three-dimensional model of the whole vehicle and set the material parameters of each component of the three-dimensional model of the whole vehicle;

[0010] S4. Establishing a three-dimensional model of the road surface;

[0011] S5. Meshing the three-dimensional road surface model and setting material parameters of the three-dimensional road surface model;

[0012] S6, assembling the vehicle 3D model and the road surface 3D model together to form a vehicle and road surface assembly model;

[0013] S7. Setting boundary conditions and applying constraints to the vehicle and road assembly model;

[0014] S8. Performing transient simulation calculation of vehicle strength;

[0015] S9. Read the vehicle strength transient simulation calculation results.

[0016] Furthermore, S1 specifically includes: using UG software to build models of various components, and then assembling the various components together to obtain a three-dimensional model of the entire vehicle.

[0017] Furthermore, S2 is specifically as follows: Importing the vehicle 3D model established in S1 into ANSA software or Hypermesh software to mesh the vehicle 3D model, with an average mesh size of 5 mm for the frame and 4 mm for the suspension.

[0018] Furthermore, S3 is specifically as follows: after completing the mesh division of the whole vehicle three-dimensional model, connecting the parts with connection relationships in the whole vehicle three-dimensional model is processed, and the material parameters of each part of the whole vehicle three-dimensional model are set according to the actual materials used for each part.

[0019] Furthermore, S4 specifically includes: using UG software to establish a three-dimensional model of the road surface.

[0020] Furthermore, S5 specifically includes: importing the three-dimensional road surface model established in S4 into ANSA software or Hypermesh software to perform meshing on the three-dimensional road surface model, and setting material parameters of the three-dimensional road surface model after the meshing is completed.

[0021] Furthermore, S6 specifically includes: assembling the vehicle 3D model processed in S3 and the road surface 3D model processed in S5 together in ANSA software or Hypermesh software to form a vehicle and road surface assembly model.

[0022] Furthermore, S7 specifically includes: setting boundary conditions and applying constraints to the vehicle and road assembly model; the boundary conditions include a static friction coefficient of 0.7 between the tire and the road, and a kinetic friction coefficient of 0.65 between the tire and the road; the imposed constraints include full three-dimensional displacement constraint of the right rear wheel, YZ two-dimensional displacement constraint of the left rear wheel, XZ two-dimensional displacement constraint of the right front wheel, and Z-direction displacement constraint of the left front wheel.

[0023] Furthermore, S8 is specifically as follows: after setting boundary conditions and applying constraints to the vehicle and road assembly model, the calculation file is exported from ANSA software or Hypermesh software, and then the calculation file is submitted to ANSYS software for vehicle strength transient simulation calculation.

[0024] Furthermore, S9 is specifically as follows: after S8 is calculated, the vehicle strength transient simulation calculation results are read using LS-PrePost software.

[0025] The present invention can perform transient strength simulation at the vehicle level during the development phase to identify potential problems. In addition, it can optimize weight reduction in areas with ample design margins, thereby shortening the vehicle development cycle and improving the economic efficiency of vehicle structural design. By establishing a three-dimensional model of the vehicle and a three-dimensional model of the road surface, the present invention can realistically and dynamically simulate the working conditions of a vehicle traveling on the road surface. By reading the stress simulation calculation results, the stress magnitude at each position can be obtained. Based on the stress simulation calculation results, the risk of the vehicle design scheme can be predicted, which can effectively shorten the development cycle of the automotive ball joint structure design and provide certain guidance for the lightweighting of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A flowchart of a method for transient simulation of vehicle strength based on actual road surface described in a specific embodiment;

[0027] Figure 2 Schematic diagram of the three-dimensional model of the whole vehicle;

[0028] Figure 3 Schematic diagram of the mesh division of the 3D model of the whole vehicle;

[0029] Figure 4 is a schematic diagram of the three-dimensional model of the road surface;

[0030] Figure 5 Schematic diagram of mesh division for the 3D road model;

[0031] Figure 6 This is a schematic diagram of the vehicle and road assembly model;

[0032] Figure 7 for Figure 6 A partial enlarged view of

[0033] Figure 8 Schematic diagram of vehicle constraints;

[0034] Figure 9 It is a schematic diagram of the vehicle driving on the road at a certain moment;

[0035] Figure 10 is the stress calculation result of the whole vehicle;

[0036] Figure 11 The stress curve of the frame changes with time. DETAILED DESCRIPTION

[0037] The present invention will be further described below with reference to the accompanying drawings.

[0038] like Figure 1 The transient simulation method of vehicle strength based on actual road surface includes the following steps:

[0039] S1. Build a three-dimensional model of the entire vehicle.

[0040] S1 is as follows: Use UG software to build the model of each component, and then assemble the components together to obtain the following Figure 2 The three-dimensional model of the entire vehicle is shown.

[0041] S2. Mesh the three-dimensional model of the vehicle established in S1.

[0042] S2 is specifically: Figure 3 As shown, the three-dimensional model of the whole vehicle established in S1 is imported into ANSA software or Hypermesh software for geometric cleaning and meshing of the three-dimensional model of the whole vehicle. The meshing is performed using the meshing function of ANSA software or Hypermesh software. The average mesh size of the frame is 5 mm, and the average mesh size of the suspension is 4 mm.

[0043] S3. Connect the components that have a connection relationship in the three-dimensional model of the whole vehicle, and set the material parameters of each component of the three-dimensional model of the whole vehicle.

[0044] S3 specifically includes: after completing the mesh division of the whole vehicle 3D model, connecting the parts with connection relationships (such as hinge connection, bolt connection) in the whole vehicle 3D model, and setting the material parameters of each part of the whole vehicle 3D model according to the actual materials used by each part.

[0045] S4. Establish a three-dimensional model of the road surface.

[0046] S4 is specifically: Use UG software to establish Figure 4 and Figure 5 The three-dimensional road surface model shown is generally modeled based on the actual road surface. In this embodiment, a twisted road is used. In other embodiments, other road surfaces such as potholes, cobblestones, etc. can also be used.

[0047] S5. Mesh the pavement three-dimensional model and set material parameters of the pavement three-dimensional model.

[0048] S5 is specifically: importing the pavement three-dimensional model established in S4 into ANSA software or Hypermesh software to mesh the pavement three-dimensional model, and setting the material parameters of the pavement three-dimensional model after the meshing is completed. In this embodiment, the material of the pavement three-dimensional model is specifically a rigid material.

[0049] S6, assembling the vehicle 3D model and the road surface 3D model together to form a vehicle and road surface assembly model;

[0050] S6 is specifically as follows: in ANSA software or Hypermesh software, the three-dimensional model of the vehicle processed in S3 and the three-dimensional model of the road surface processed in S5 are assembled together to form the following Figure 6 and Figure 7 The vehicle and road assembly model is shown; if the tire is not in contact with the road, the road 3D model needs to be adjusted until the tire is in contact with the road. After contact, use ANSA software or Hypermesh software to check the interference between the vehicle and the road until there is no interference between the two.

[0051] S7. Setting boundary conditions and applying constraints to the vehicle and road assembly model;

[0052] S7 specifically includes setting boundary conditions and applying constraints to the vehicle and road assembly model; the boundary conditions include the vehicle speed and the friction coefficient between the tire and the road. According to the contact relationship and friction relationship between the tire and the road, the boundary conditions are set as follows: the static friction coefficient between the tire and the road is 0.7 and the dynamic friction coefficient between the tire and the road is 0.65; Figure 8 As shown in the figure, the constraints on the entire vehicle are specifically the wheels. The vehicle constraints are as follows: the right rear wheel is fully constrained in X, Y, and Z directions; the left rear wheel is constrained in Y and Z directions; the right front wheel is constrained in X and Z directions; and the left front wheel is constrained in Z direction only. By properly setting the constraints, the frame can be kept stationary while the road surface moves backward relative to the vehicle, improving calculation accuracy.

[0053] S8. Performing transient simulation calculation of vehicle strength;

[0054] S8 is specifically: Figure 9 As shown in the figure, after setting boundary conditions and applying constraints to the vehicle and road assembly model, the calculation file is exported from ANSA software or Hypermesh software, and then submitted to ANSYS software for vehicle strength transient simulation calculation.

[0055] S9. Read the vehicle strength transient simulation calculation results.

[0056] S9 is as follows: After S8 is completed, the vehicle strength transient simulation calculation results are read using LS-PrePost software, such as Figure 10 and Figure 11 As shown in the figure, the transient vehicle strength simulation results include stress, deformation, strain, acceleration, and velocity calculations. Furthermore, by reading the stress simulation results, the stress magnitude at each location can be determined. This can be used to predict the risk of the vehicle design, allowing for optimization of more critical components or connections, while also reducing the weight of less critical components or connections.

Claims

1. A transient simulation method of vehicle strength based on actual road surface, characterized in that: The following steps are involved: S1. Establish a three-dimensional model of the whole vehicle; S2, meshing the three-dimensional model of the whole vehicle established in S1; S3, connecting the components that have a connection relationship in the three-dimensional model of the whole vehicle, and setting material parameters of each component of the three-dimensional model of the whole vehicle; S4, establishing a three-dimensional model of the road surface; S5, meshing the road surface three-dimensional model and setting material parameters of the road surface three-dimensional model; S6, assembling the whole vehicle three-dimensional model and the road surface three-dimensional model together to form a whole vehicle and road surface assembly model; S7, setting boundary conditions and applying constraints to the vehicle and road assembly model; S8, performing transient simulation calculation of vehicle strength; S9, reading the vehicle strength transient simulation calculation results; In S7, the boundary conditions include a static friction coefficient between the tire and the road surface of 0.7 and a dynamic friction coefficient between the tire and the road surface of 0.65; the imposed constraints include full displacement constraint of the right rear wheel in three directions, YZ displacement constraint of the left rear wheel in two directions, XZ displacement constraint of the right front wheel in two directions, and Z displacement constraint of the left front wheel in only direction; During the transient simulation calculation of vehicle strength, the frame of the 3D model of the whole vehicle remains stationary, and the 3D model of the road surface moves backward relative to the 3D model of the whole vehicle.

2. The method for transient simulation of vehicle strength based on actual road surface according to claim 1, characterized in that: S1 specifically includes: using UG software to build models of various components, and then assembling the components together to obtain a three-dimensional model of the entire vehicle.

3. The method for transient simulation of vehicle strength based on actual road surface according to claim 2, characterized in that: S2 is specifically as follows: importing the three-dimensional model of the whole vehicle established in S1 into ANSA software or Hypermesh software to mesh the three-dimensional model of the whole vehicle, with an average mesh size of 5 mm for the frame and an average mesh size of 4 mm for the suspension.

4. The method for transient simulation of vehicle strength based on actual road surface according to claim 3 is characterized in that: S3 is specifically as follows: after completing meshing of the whole vehicle three-dimensional model, connecting the parts with connection relationship in the whole vehicle three-dimensional model, and setting the material parameters of each part of the whole vehicle three-dimensional model according to the materials actually used for each part.

5. The method for transient simulation of vehicle strength based on actual road surface according to claim 4 is characterized in that: S4 specifically includes: using UG software to establish a three-dimensional model of the road surface.

6. The method for transient simulation of vehicle strength based on actual road surface according to claim 5, characterized in that: S5 specifically includes: importing the three-dimensional road surface model established in S4 into ANSA software or Hypermesh software to mesh the three-dimensional road surface model, and setting material parameters of the three-dimensional road surface model after meshing is completed.

7. The method for transient simulation of vehicle strength based on actual road surface according to claim 6, characterized in that: S6 is specifically: assembling the whole vehicle three-dimensional model processed in S3 and the road surface three-dimensional model processed in S5 together in ANSA software or Hypermesh software to form a whole vehicle and road surface assembly model.

8. The method for transient simulation of vehicle strength based on actual road surface according to claim 7, characterized in that: S8 is specifically as follows: after setting boundary conditions and applying constraints to the vehicle and road assembly model, the calculation file is exported from ANSA software or Hypermesh software, and then the calculation file is submitted to ANSYS software for vehicle strength transient simulation calculation.

9. The method for transient simulation of vehicle strength based on actual road surface according to claim 8, characterized in that: S9 is specifically as follows: after S8 is calculated, the vehicle strength transient simulation calculation results are read using LS-PrePost software.

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