Vehicle-mounted frame structure optimization method, vehicle-mounted frame and automobile

Abstract

The application belongs to the technical field of automobiles, and discloses a vehicle-mounted frame structure optimization method, a vehicle-mounted frame and an automobile. The vehicle-mounted frame structure optimization method can most truly simulate the stress condition of the vehicle-mounted frame under real road conditions by including the automobile load spectrum into the boundary condition and performing finite element calculation, so that it can truly and accurately determine whether the vehicle-mounted frame meets the lightness and stiffness requirements. In addition, the value range of the structure parameters is determined according to the actual operating conditions of the whole vehicle, the minimum mass of the vehicle-mounted frame is taken as the objective function, the optimal solution of the structure parameters is obtained through parameterized modeling, the value range of the parameters in the parameterized modeling can be reduced, the calculation time can be shortened, and the calculation efficiency can be improved, so that the optimal design parameters of the vehicle-mounted frame can be obtained in the fastest time, and the design efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the automobile technical field, and in particular to a vehicle frame structure optimization method, a vehicle frame and an automobile. BACKGROUND

[0002] The vehicle frame system itself should have sufficient strength and reasonable stiffness to ensure that the stress of each part of the frame structure is within a reasonable range under various use conditions, so that the relative positions between the related components mounted thereon remain basically unchanged during the automobile driving process, and the deformation of the vehicle frame itself is minimized, otherwise, the reliability of the external components will be affected, and even the vehicle frame will be deformed or broken, or the normal function of these components will be affected.

[0003] The frame system has many design structures and variables, and the strength and stiffness analysis of the frame structure currently needs repeated calculation, the optimization process is time-consuming and laborious, there is a lack of effective optimization scheme, and it is difficult to obtain an optimal solution scheme; at the same time, there is a lack of effective actual load spectrum boundary conditions, so that the optimal scheme obtained by design will also have risks, resulting in repeated design. SUMMARY

[0004] The purpose of the present application is to provide a vehicle frame structure optimization method which can quickly obtain the optimal design parameters of the vehicle frame and improve the design efficiency.

[0005] To achieve this purpose, the present application adopts the following technical scheme:

[0006] The vehicle frame structure optimization method comprises the following steps:

[0007] S1, establishing a frame grid model including a chassis and a simplified vehicle frame;

[0008] S2, determining boundary conditions including an automobile load spectrum;

[0009] S3, inputting the boundary conditions into simulation software and performing finite element calculation;

[0010] S4, judging whether the stiffness and strength of the vehicle frame meet the requirements according to the finite element calculation results, if not, executing step S5, and if yes, executing step S6;

[0011] S5, adding a support structure to the vehicle frame and executing step S1;

[0012] S6, judging whether to add a support structure, if yes, executing step S7, and if no, executing step S8;

[0013] S7, outputting structure parameters including the beam section size, the beam plate thickness and the support structure position of the vehicle frame, and executing step S9;

[0014] S8, output the structure parameters including the beam section size and the beam plate thickness of the vehicle-mounted frame, and perform step S9;

[0015] S9, determine the value range of the structure parameters according to the actual running condition of the whole vehicle;

[0016] S10, parameterize modeling and obtain the optimal solution of the structure parameters with the minimum mass of the vehicle-mounted frame as the objective function.

[0017] Optionally, before step S1, the method further comprises step S101 of determining the position of the vehicle-mounted frame on the chassis and the function of the vehicle-mounted frame.

[0018] Optionally, in step S2, the step of determining the load spectrum comprises:

[0019] S201, determining the measurement points of the load spectrum to be collected according to the position of the vehicle-mounted frame on the chassis;

[0020] S202, collecting the load spectrum under the actual road condition.

[0021] Optionally, the actual road condition is one or a combination of the user road condition and the test track road condition.

[0022] Optionally, in step S1, the boundary conditions further comprise the supporting mode, the connecting mode and the material mechanics characteristic parameters of the vehicle-mounted frame.

[0023] Optionally, the beam of the vehicle-mounted frame is a box beam, and the beam section size comprises the height, the width and the round corner size of the beam section.

[0024] Optionally, in step S10, the algorithm for obtaining the optimal solution of the structure parameters is a gradient optimization algorithm.

[0025] Optionally, after step S10, the method further comprises a verification step S11 of designing and manufacturing the vehicle-mounted frame according to the optimal solution of the structure parameters, and performing numerical simulation verification, bench test and whole vehicle road test on the vehicle-mounted frame to determine whether the vehicle-mounted frame meets the requirements.

[0026] Another object of the present application is to provide a vehicle-mounted frame designed and optimized by the vehicle-mounted frame structure optimization method according to any one of the above-mentioned schemes.

[0027] Still another object of the present application is to provide an automobile comprising the vehicle-mounted frame according to any one of the above-mentioned schemes.

[0028] Beneficial effects:

[0029] The vehicle-mounted frame structure optimization method in the application can most truly simulate the stress condition of the vehicle-mounted frame under real road conditions by including the automobile load spectrum into the boundary condition and performing finite element calculation, so as to truly and accurately determine whether the vehicle-mounted frame meets the lightness and stiffness requirements; and the value range of the structure parameters is determined according to the actual running condition of the whole vehicle, the minimum mass of the vehicle-mounted frame is taken as the objective function, the parameterized modeling is performed and the optimal solution of the structure parameters is obtained, so as to reduce the parameter value range in the parameterized modeling, shorten the calculation time, improve the calculation efficiency, so as to obtain the optimal design parameters of the vehicle-mounted frame in the fastest time and improve the design efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a flow chart of the vehicle-mounted frame structure optimization method provided by the embodiment of the application;

[0031] Figure 2 is a schematic view of the vehicle-mounted frame mounted on the chassis provided by the embodiment of the application;

[0032] Figure 3 is a schematic view of the beam section of the vehicle-mounted frame provided by the embodiment of the application.

[0033] In the drawings:

[0034] 1, chassis; 2, vehicle-mounted frame; 3, support structure. DETAILED DESCRIPTION

[0035] The application will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the application, but not to limit the application. In addition, it should be noted that, for the convenience of description, only the parts related to the application are shown in the drawings, but not all the structures.

[0036] In the description of the application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood in a broad sense, for example, it can be fixedly connected, or detachably connected, or integrated; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0037] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature is "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the first feature is higher in horizontal height than the second feature. The first feature is "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the first feature is lower in horizontal height than the second feature.

[0038] In the description of the present embodiment, the terms "upper", "lower", "right", "left", and other orientation or position relationships are based on the orientation or position relationships shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0039] Please refer to Figure 1 In the present embodiment, the vehicle frame structure optimization method comprises the steps of:

[0040] S1, establishing a frame grid model comprising a chassis 1 and a simplified vehicle frame 2;

[0041] As a preferred embodiment, before step S1, there is also a step S101 of determining the position of the vehicle frame 2 on the chassis 1 and the function of the vehicle frame 2. The vehicle frame 2 thus set is more in line with the actual situation, improving the reliability of the vehicle frame structure optimization method.

[0042] In step S1, the simplified vehicle frame 2 referred to herein refers to the simplest structure of the vehicle frame 2 that can meet the function of the vehicle frame 2. The shape, connection relationship and connection mode of each component of the vehicle frame 2 are simplified to reduce the complexity of the calculation model, shorten the calculation time and improve the calculation efficiency.

[0043] Further, in step S1, the boundary conditions also include the support mode, connection mode and material mechanics characteristic parameters of the vehicle frame 2. These boundary conditions are the required condition parameters for inputting into the simulation software. Those skilled in the art can select the input material mechanics characteristic parameters according to the actually used software, such as material type, elastic modulus, Poisson's ratio, mass density, tensile strength and yield strength, etc. which will not be repeated here.

[0044] As Figure 2 and Figure 3As shown, the vehicle-mounted frame 2 in the embodiment is fixed to the chassis 1, the beams of the vehicle-mounted frame 2 are box beams, and a plurality of box beams are perpendicularly arranged to form the vehicle-mounted frame 2. The box beams constituting the vehicle-mounted frame 2 have the same cross-sectional size, which includes the height H, the width H and the round corner size R of the beam cross section.

[0045] S2, determining the boundary conditions including the automobile load spectrum;

[0046] The automobile load spectrum is used as the boundary condition, so that the vehicle-mounted frame structure optimization method is more consistent with the actual road conditions, and the reliability and authenticity of the vehicle-mounted frame structure optimization method can be improved.

[0047] The determination of the automobile load spectrum includes S201, determining the measurement points of the load spectrum according to the position of the vehicle-mounted frame 2 on the chassis 1; and S202, collecting the load spectrum under actual road conditions. Further, the actual road conditions are one or a combination of the user road conditions or the test track road conditions. The user road conditions refer to the use of the vehicle by the user in the actual use process, which is usually reflected in two aspects: load signal and environmental factors; the user road conditions can best reflect the actual vehicle operation condition, but the test cost is high when the test time span is long, the required space is large, and a large number of users are required to test. The test track road conditions only need to run the vehicle for a specified number of laps in a standard site, the test track includes the most typical vehicle running road conditions, can better simulate the running load of the vehicle, can reduce the cost and time of load spectrum collection, and shorten the development cycle of the vehicle, but the test track road conditions still have some differences from the actual road conditions, and cannot most accurately simulate the vehicle operation condition in use. The skilled in the art can select one or a combination of the user road conditions or the test track road conditions according to the specific requirements to collect the load spectrum.

[0048] S3, inputting the boundary conditions into the simulation software and performing finite element calculation;

[0049] S4, judging whether the stiffness and strength of the vehicle-mounted frame 2 meet the requirements according to the finite element calculation result, if not, performing step S5, and if yes, performing step S6;

[0050] S5, adding a support structure 3 to the vehicle-mounted frame 2, and performing step S1; the support structure 3 is made of a box beam and fixed to the vehicle-mounted frame 2, and the shape and size of the beam cross section of the box beam are the same as those of the box beam used to make the vehicle-mounted frame 2.

[0051] S6, judging whether the support structure 3 is added, if yes, performing step S7, and if not, performing step S8;

[0052] S7, output the structure parameters including the beam section size of the vehicle-mounted frame 2, the beam plate thickness R and the support structure 3 position, and perform step S9; as Figure 2 As shown, the structure parameters of the support position include the positions of the support mechanism in the X direction, the Y direction and the Z direction relative to the reference point on the chassis 1.

[0053] S8, output the structure parameters including the beam section size of the vehicle-mounted frame 2 and the beam plate thickness, and perform step S9;

[0054] S9, determine the value range of the structure parameters according to the actual running condition of the whole vehicle;

[0055] S10, parameterize modeling and obtain the optimal solution of the structure parameters with the minimum mass of the vehicle-mounted frame 2 as the objective function.

[0056] In step S10, the algorithm for obtaining the optimal solution of the structure parameters is the gradient optimization algorithm. Parameterized modeling is to re-input the structure parameters of the beam section size, the beam plate thickness R and the support structure 3 position into the grid model for calculation to obtain the stiffness and strength of the vehicle-mounted frame 2 and judge whether the requirements are met, so as to meet the strength and stiffness requirements under the condition that the objective function, i.e. the mass of the vehicle-mounted frame 2, is minimum. The gradient optimization algorithm can gradually increase or gradually reduce the calculation parameters according to the gradient of the parameter change, and perform traversal calculation on the calculation parameters, so as to obtain the optimal solution within a limited step.

[0057] The vehicle-mounted frame structure optimization method in the embodiment can most realistically simulate the stress condition of the vehicle-mounted frame 2 under real road conditions by including the vehicle load spectrum into the boundary conditions and performing finite element calculation, so as to truly and accurately judge whether the vehicle-mounted frame 2 meets the lightness and stiffness requirements; and according to the actual running condition of the whole vehicle, the value range of the structure parameters is determined, the optimal solution of the structure parameters is obtained by parameterizing modeling with the minimum mass of the vehicle-mounted frame 2 as the objective function, the parameter value range during parameterized modeling can be reduced, the calculation time can be shortened, the calculation efficiency can be improved, so that the optimal design parameters of the vehicle-mounted frame 2 can be obtained in the fastest time, and the design efficiency can be improved.

[0058] Specifically, step S10 is followed by a verification step S11: the vehicle-mounted frame 2 is designed and manufactured according to the optimal solution of the structural parameters, and the vehicle-mounted frame 2 is subjected to numerical simulation verification, bench testing and whole-vehicle road testing to determine whether the vehicle-mounted frame 2 meets the requirements. Through the verification step, it can be determined whether the optimal structural parameters of the vehicle-mounted frame 2 selected by the vehicle-mounted frame 2 structural optimization design method can meet the design requirements. The numerical simulation verification, bench testing and whole-vehicle road testing verification are layer-by-layer advanced and gradually close to the real road conditions, which can optimize the verification process, shorten the verification time, improve the verification efficiency, and ensure that the vehicle-mounted frame 2 is not only optimal in parameters, but also does not affect the mechanical performance and service life.

[0059] The embodiment also provides a vehicle-mounted frame 2, which is designed and optimized by the vehicle-mounted frame structural optimization method according to any one of the above-mentioned solutions. Further, the embodiment also provides an automobile, which comprises the vehicle-mounted frame 2 according to any one of the above-mentioned solutions.

[0060] Obviously, the above-mentioned embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of the present application. It is unnecessary and impossible to enumerate all the embodiments here. Any modification, equivalent substitution and improvement within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method for optimizing a vehicle frame structure, characterized by, The method comprises the steps of: S1, establishing a frame grid model comprising a chassis (1) and a simplified vehicle frame (2); S2, determining boundary conditions including a vehicle load spectrum; S3, inputting the boundary conditions into simulation software and performing finite element calculation; S4, judging whether the stiffness and strength of the vehicle frame (2) meet the requirements according to the finite element calculation results, if not, performing step S5, if yes, performing step S6; S5, adding a support structure (3) to the vehicle frame (2) and performing step S1; S6, judging whether to add the support structure (3), if yes, performing step S7, if not, performing step S8; S7, outputting structure parameters including beam section size, beam plate thickness of the vehicle frame (2) and position of the support structure (3), and performing step S9; S8, outputting structure parameters including beam section size and beam plate thickness of the vehicle frame (2), and performing step S9; S9, determining the value range of the structure parameters according to the actual operating conditions of the whole vehicle; S10, parameterizing modeling with the minimum mass of the vehicle frame (2) as the objective function, and obtaining the optimal solution of the structure parameters; In step S2, the step of determining the load spectrum comprises: S201, determining the measurement points of the load spectrum according to the position of the vehicle frame (2) on the chassis (1); S202, collecting the load spectrum under actual road conditions.

2. The in-vehicle frame structure optimization method according to claim 1, characterized by, Before step S1, there is also a step S101 of determining the position of the vehicle frame (2) on the chassis (1) and the function of the vehicle frame (2).

3. The in-vehicle frame structure optimization method according to claim 1, characterized by, The actual road conditions are one or a combination of user road conditions or test track road conditions.

4. The in-vehicle frame structure optimization method according to claim 1, characterized by, In step S2, the boundary conditions also include the support mode, connection mode and material mechanics characteristic parameters of the vehicle frame (2).

5. The in-vehicle frame structure optimization method according to claim 1, characterized by, The beam of the vehicle frame (2) is a box beam, and the beam section size includes the height, width and fillet size of the beam section.

6. The in-vehicle frame structure optimization method according to claim 4, characterized by, In step S10, the algorithm for obtaining the optimal solution of the structure parameters is a gradient optimization algorithm.

7. The in-vehicle frame structure optimization method according to any one of claims 1 to 6, characterized by, After step S10, there is also a verification step S11 of designing and manufacturing the vehicle frame (2) according to the optimal solution of the structure parameters, and performing numerical simulation verification, bench test and whole vehicle road test on the vehicle frame (2) to judge whether the vehicle frame (2) meets the requirements.

8. A vehicle frame, characterized by The vehicle frame structure is designed and optimized by the method of any one of claims 1-7.

9. An automobile characterized by The vehicle frame (2) according to claim 8.

Images