Automobile front cover anti-deformation design method and device based on CAE simulation

Abstract

The invention discloses an automobile front cover anti-deformation design method and device based on CAE simulation. Front cover carrying deformation simulation analysis, front cover container containing deformation simulation analysis, front cover coating electrophoresis deformation simulation analysis, front cover coating baking deformation simulation analysis and front cover edge local rigidity simulation analysis are carried out. The deformation condition of the front cover possibly generated at the process manufacturing end can be predicted, corresponding optimization is carried out, and the appearance quality problem that the front cover is prone to deformation of a real vehicle in the later period is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of automotive CAE simulation, and particularly relates to a method and device for anti-deformation design of an automotive hood based on CAE simulation. Background Art

[0002] As an important part of the vehicle body, the automotive hood undertakes the important function of protecting the components in the front cabin. On the one hand, the automotive hood can not only block rain, external sundries, etc. from entering the front cabin, protect the component systems and peripheral accessories in the front cabin, and improve the service life of the vehicle power system; on the other hand, when the vehicle collides, the automotive hood can also play a role in resisting external impacts and providing safety buffering. At the same time, the dimensional accuracy of the automotive hood directly affects the aesthetics of the vehicle. However, during the production and manufacturing process, after a series of processes such as lifting, storage and transportation, painting electrophoresis, and painting baking, the hood is prone to deformation, which affects the appearance gap and surface difference matching between the hood and the surrounding fittings such as headlights, front bumpers, and fenders, resulting in poor appearance quality problems.

[0003] The existing means for controlling appearance gap and surface difference are traditional trial-and-error methods, that is, repeated adjustments are made according to the actual deformation amount of the hood during the physical manufacturing stage. The main problems are that there are no effective pre-prediction and control means, problems can only be found in the physical stage, and repeated trial-and-error results in high later rectification costs and long cycles, which is not conducive to product development and efficiency improvement. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and device for anti-deformation design of an automotive hood based on CAE simulation to predict the possible deformation of the hood at the process manufacturing end and perform corresponding optimizations to solve the appearance quality problem of the hood being prone to deformation in the later actual vehicle.

[0005] In the first aspect, the method for anti-deformation design of an automotive hood based on CAE simulation according to the present invention includes the steps of: S1. Establish a finite element model of the hood structure and determine the measuring point positions.

[0006] S2. Select a lifting position on the finite element model of the hood structure, perform a lifting deformation simulation analysis of the hood, obtain the lifting position when all measuring points meet the first simulation requirements (preset), and use this lifting position as the actual lifting position of the hood.

[0007] S3. Select a fixture support position on the finite element model of the hood structure, determine the storage method, perform a fixture storage deformation simulation analysis of the hood, obtain the fixture support position and storage method when all measuring points meet the second simulation requirements (preset), use this fixture support position as the actual support position of the hood on the fixture, and use this storage method as the actual storage method of the hood on the fixture.

[0008] S4. Select the electrophoresis fixture support positions on the finite element model of the front hood structure and / or optimize the local structure of the front hood, conduct simulation analysis on the deformation of the front hood during electrophoretic coating, and obtain the electrophoresis fixture support positions and the finite element model of the front hood structure when all measurement points meet the (preset) third simulation requirement. Use this electrophoresis fixture support position as the actual support position during the electrophoretic coating of the front hood.

[0009] S5. On the finite element model of the front hood structure after the simulation analysis of the deformation of the front hood during electrophoretic coating (i.e., the finite element model of the front hood structure when all measurement points meet the third simulation requirement in S4), select the baking fixture support positions and / or optimize the local structure of the front hood, conduct simulation analysis on the deformation of the front hood during baking after electrophoretic coating, and obtain the baking fixture support positions and the finite element model of the front hood structure when all measurement points meet the (preset) fourth simulation requirement. Use this baking fixture support position as the actual support position during the baking of the front hood after electrophoretic coating.

[0010] S6. Based on the finite element model of the front hood structure after the simulation analysis of the deformation of the front hood during baking after electrophoretic coating (i.e., when all measurement points meet the fourth simulation requirement in S5) or after further optimizing the local structure of the front hood, conduct simulation analysis on the local stiffness of the front hood edge. When the local stiffness of the front hood edge is greater than the preset stiffness target value, complete the anti-deformation design of the front hood to obtain a suitable automotive front hood and the manufacturing process requirements. The manufacturing end includes: handling (after the outer panel of the front hood is buckled with the inner panel of the front hood), storing and transporting, electrophoretic coating, and baking after electrophoretic coating.

[0011] Preferably, step S2 is specifically as follows: First, select the handling positions on the finite element model of the front hood structure, then conduct simulation analysis on the deformation of the front hood during handling to obtain the first plastic deformation results of all measurement points; if the first plastic deformation results of all measurement points meet the first simulation requirement, use this handling position as the actual handling position of the front hood; otherwise, change the handling position (for example, change the handling position to a position with a stronger local structure), and then conduct simulation analysis on the deformation of the front hood during handling until the first plastic deformation results of all measurement points meet the first simulation requirement.

[0012] Among them, the steps of conducting simulation analysis on the deformation of the front hood during handling to obtain the first plastic deformation results of all measurement points include: First, apply constraints according to the transfer process: If the transfer process is manual handling and transfer, apply constraints to the nodes at the handling positions of the front hood; if the transfer process is robot gripper transfer, apply constraints to the nodes at the gripper clamping parts of the robot.

[0013] Then, first apply an a-fold gravitational field under the constraints, and then unload the gravitational field, and calculate the first plastic deformation results of all measurement points through simulation analysis; a represents a preset first value, and a > 1.

[0014] Since different lifting positions will cause changes in the force application points of the front cover, thereby affecting the distribution of stress in the material; if the force application point is close to the weak area of the front cover structure, it may cause local stress concentration and increase the risk of deformation or damage. In addition, inappropriate lifting positions may cause excessive bending or twisting of the front cover during handling; such deformation not only affects the appearance, but may also damage the functionality and structural integrity of the front cover, affect the mating accuracy with other components, and thus affect the assembly quality and performance of the entire vehicle. Therefore, when designing the front cover for anti-deformation, it is necessary to consider the deformation that may occur during lifting; through simulation analysis, obtain the lifting positions that meet the requirements, so as to eliminate the influence of the lifting positions on the front cover.

[0015] Preferably, the step S3 is specifically as follows: First, select the container support position on the finite element model of the front cover structure, determine the placement method, and then conduct a simulation analysis of the deformation of the front cover when placed in the container to obtain the second plastic deformation results of all measurement points; if the second plastic deformation results of all measurement points meet the second simulation requirements, then use this container support position as the actual support position of the front cover on the container, and use this placement method as the actual placement method of the front cover on the container; otherwise, change the placement method and / or change the container support position to a position with a stronger local structure, and then conduct a simulation analysis of the deformation of the front cover when placed in the container until the second plastic deformation results of all measurement points meet the second simulation requirements.

[0016] Among them, the steps of conducting a simulation analysis of the deformation of the front cover when placed in the container to obtain the second plastic deformation results of all measurement points include: First, apply corresponding degree-of-freedom constraints to the nodes at the container support position (i.e., the contact area nodes between the front cover and the container support part).

[0017] Then, under the constraint, first apply a gravity field of b times, and then unload the gravity field. Through simulation analysis and calculation, obtain the second plastic deformation results of all measurement points; b represents a preset second value, and b > 1.

[0018] Since the placement position and placement method of the container directly determine the force support points of the front cover, if the support points of the front cover are insufficient or the positions are unreasonable, the front cover may deform due to shaking and tilting. Incorrect long-term placement positions may cause the front cover material to be continuously stressed in some parts, resulting in fatigue damage and gradually accumulating to form visible deformation. Improper placement positions may cause the front cover to have minor deformations during storage, and these deformations may be amplified during subsequent assembly processes, affecting the assembly quality of the entire vehicle. Therefore, when designing the front cover, it is necessary to consider the deformation that may occur due to the placement position and placement method of the front cover on the container; through simulation analysis, obtain the placement positions and placement methods that meet the requirements, so as to eliminate the influence of the placement positions and placement methods on the front cover.

[0019] Preferably, the step S4 is specifically as follows: First, select the support positions of the electrophoresis fixture on the finite element model of the front cover structure, and then perform the simulation analysis of the deformation during the electrophoresis painting of the front cover to obtain the third plastic deformation results of all measuring points; if the third plastic deformation results of all measuring points meet the third simulation requirements, then use this support position of the electrophoresis fixture as the actual support position during the electrophoresis painting of the front cover; otherwise, change the support position of the electrophoresis fixture and / or optimize the local structure of the front cover, and then perform the simulation analysis of the deformation during the electrophoresis painting of the front cover until the third plastic deformation results of all measuring points meet the third simulation requirements.

[0020] Among them, the steps of performing the simulation analysis of the deformation during the electrophoresis painting of the front cover to obtain the third plastic deformation results of all measuring points include: S421. In the fluid analysis software, according to the (preset) flipping process, working conditions of the electrophoresis painting, and the preset simulation analysis requirements, divide the finite element model of the front cover structure into different postures at equal angles, and adjust the posture of the finite element model of the front cover structure at different angles.

[0021] S422. Calculate the speeds of the front cover at different angular postures according to the moving speed of the electrophoresis painting transportation track and the flow rate of the electrophoresis solution.

[0022] S423. Establish a calculation domain, input the preset calculation speed, carry out the simulation analysis, and export the electrophoresis impact loads of different postures of the front cover.

[0023] S424. In the structural analysis software, adjust the posture of the finite element model of the front cover structure to make it correspond one by one with the posture of the finite element model of the front cover structure in the fluid analysis software, and constrain the six degrees of freedom in three directions at the hinge installation points of the front cover.

[0024] S425. Establish a local coordinate system at the position where the electrophoresis fixture supports the inner panel of the front cover, with the normal direction of the coordinate system perpendicular to the plane of the inner panel of the front cover. Under the local coordinates, constrain the normal degree of freedom at the support position of the electrophoresis fixture.

[0025] S426. First, apply the electrophoresis impact load and the b-fold gravity field under the constraints, and then unload the gravity field and the electrophoresis impact load. Calculate and obtain the third plastic deformation results of all measuring points through the simulation analysis; b represents a preset second value, and b > 1.

[0026] Preferably, if the third plastic deformation results of all measuring points obtained from the simulation analysis of the deformation during the electrophoresis painting of the front cover based on the current support position of the electrophoresis fixture do not all meet the third simulation requirements, then change the support position of the electrophoresis fixture (corresponding to the support hole position of the electrophoresis fixture) to the next selected support position I, and then perform the simulation analysis of the deformation during the electrophoresis painting of the front cover until the third plastic deformation results of all measuring points meet the third simulation requirements.

[0027] If the support position of the electrophoresis fixture has been changed to the last preselected support position I, and the third plastic deformation results of all measurement points still do not all meet the third simulation requirements, then maintain this last support position I, and then optimize the local structure of the front cover. After optimizing the local structure of the front cover, perform the electrophoresis deformation simulation analysis of the front cover painting until the third plastic deformation results of all measurement points meet the third simulation requirements.

[0028] Take the support position of the electrophoresis fixture when the third plastic deformation results of all measurement points meet the third simulation requirements as the actual support position during the electrophoresis of the front cover painting.

[0029] During the electrophoresis process, when the vehicle body enters the electrophoresis tank, the electrophoresis solution will generate an impact force on the front cover. If the impact force is too large and the sheet metal strength of the front cover is insufficient, especially when the front cover enters and exits the tank, it may cause the front cover to bulge or deform in other forms. In addition, if the support position of the electrophoresis fixture is designed unreasonably and cannot effectively support the front cover, it may cause the front cover to deform due to uneven stress during the electrophoresis process. Therefore, when designing the front cover, it is necessary to consider the possible deformation conditions during the electrophoresis of the front cover painting; through simulation analysis, obtain the support position of the electrophoresis fixture that meets the requirements and the appropriate local structure of the front cover, so as to eliminate the influence of the electrophoresis painting on the front cover.

[0030] Preferably, the step S5 is specifically as follows: First, select the support position of the baking fixture on the finite element model of the front cover structure after the electrophoresis deformation simulation analysis of the front cover, and then perform the baking deformation simulation analysis of the front cover painting to obtain the fourth plastic deformation results of all measurement points; if the fourth plastic deformation results of all measurement points meet the fourth simulation requirements, then take this support position of the baking fixture as the actual support position during the baking of the front cover painting; otherwise, change the support position of the baking painting and / or optimize the local structure of the front cover, and then perform the baking deformation simulation analysis of the front cover painting until the fourth plastic deformation results of all measurement points meet the fourth simulation requirements.

[0031] Among them, the steps of performing the baking deformation simulation analysis of the front cover painting and obtaining the fourth plastic deformation results of all measurement points include: S521. Obtain the three-dimensional geometric data of the front cover and the drying boundary parameters of the drying chamber.

[0032] S522. Import the three-dimensional geometric data of the front cover into the pre-processing software for surface mesh generation to form a surface mesh in STL format, and import the surface mesh in STL format into the fluid simulation software for mesh repair and reconstruction to form a fluid mesh model.

[0033] S523. Determine the simulation space based on the drying boundary parameters of the drying chamber. Adjust the attitude of the fluid mesh model in the software according to the actual drying position and angle of the front hood (preset). Input the wind speed and heating temperature that change with time into the fluid simulation software. Set the initial temperature and drying temperature parameters of the vehicle body. Set the air inlet velocity boundary and the air outlet boundary pressure. Set the fluid calculation time step and the iteration threshold. Establish a drying temperature field model for the front hood and conduct fluid simulation calculations to output the temperature field on the surface of the front hood that changes with time.

[0034] S524. In the structural analysis software, constrain the six degrees of freedom in three directions of the nodes at the hinge mounting points of the front hood.

[0035] S525. Establish a local coordinate system at the support position of the baking fixture. The normal direction of the coordinate system is perpendicular to the inner panel plane of the front hood. Under the local coordinates, constrain the normal degree of freedom at the support position of the baking fixture.

[0036] S526. First apply the temperature field and the b-fold gravitational field under the constraints, and then unload the temperature field and the gravitational field. Obtain the fourth plastic deformation results of all measurement points through simulation analysis and calculation.

[0037] Preferably, if not all of the fourth plastic deformation results of all measurement points obtained from the front hood painting and baking deformation simulation analysis based on the current support position of the baking fixture meet the fourth simulation requirements, change the support position of the baking fixture (corresponding to the support hole position of the baking fixture) to the next preselected support position II, and then conduct the front hood painting and baking deformation simulation analysis until all of the fourth plastic deformation results of all measurement points meet the fourth simulation requirements.

[0038] If the support position of the baking fixture has been changed to the last preselected support position II and not all of the fourth plastic deformation results of all measurement points still meet the fourth simulation requirements, maintain this last support position II, then optimize the local structure of the front hood. After optimizing the local structure of the front hood, conduct the front hood painting and baking deformation simulation analysis until all of the fourth plastic deformation results of all measurement points meet the fourth simulation requirements.

[0039] Take the support position of the baking fixture when all of the fourth plastic deformation results of all measurement points meet the fourth simulation requirements as the actual support position during the front hood painting and baking.

[0040] Due to the differences in the materials of the inner and outer panels of the front hood in terms of coefficient of thermal expansion, springback rate, stiffness, etc.; during the painting and baking process, the inner and outer panels of the front hood will expand due to the increase in temperature and contract after cooling. If the expansion and contraction of the inner and outer panels are inconsistent, deformation will occur. In addition, the support positions of the baking fixture also have an important impact on the deformation of the front hood; if the support points are too concentrated or the support is insufficient, the front hood is prone to deformation during baking. Therefore, when designing the front hood, it is necessary to consider the possible deformation during the painting and baking of the front hood; through simulation analysis, the support positions of the baking fixture that meet the requirements and the appropriate local structure of the front hood are obtained, so as to eliminate the influence of painting and baking on the front hood.

[0041] Preferably, the step S6 is specifically: based on the finite element model of the front hood structure after the simulation analysis of the deformation of the front hood during painting and baking, perform the simulation analysis of the local stiffness of the front hood edge to obtain the local stiffness of all loading points; if the local stiffness of all loading points is greater than the preset stiffness target value, the anti-deformation design of the front hood is completed; otherwise, optimize the local structure of the front hood, and then perform the simulation analysis of the local stiffness of the front hood edge until the local stiffness of all loading points is greater than the preset stiffness target value.

[0042] Preferably, the steps of performing the simulation analysis of the local stiffness of the front hood edge to obtain the local stiffness of all loading points include: First, remove the front hood hinge and constrain all six degrees of freedom in three directions of all nodes at the edge of the inner panel ring beam of the front hood.

[0043] Secondly, select a loading point at a preset length L interval at the outer edge position of the inner panel of the front hood, and establish a local coordinate system at the loading point, with the normal direction of the coordinate system perpendicular to the inner panel of the front hood, and then apply a load F along the normal direction of the coordinate system.

[0044] Finally, carry out the local stiffness analysis of the front hood edge, output the Z-direction displacement d of all loading points, and use: K = F / d to calculate the local stiffness K of all loading points.

[0045] After performing the simulation analysis of the deformation of the front hood during lifting, the simulation analysis of the deformation of the front hood when placed in a container, the simulation analysis of the deformation of the front hood during painting and electrophoresis, and the simulation analysis of the deformation of the front hood during painting and baking, the front hood needs to meet the anti-deformation stiffness requirements. If the stiffness of the front hood is insufficient, the local structure of the front hood needs to be optimized accordingly to meet the anti-deformation stiffness requirements.

[0046] In a second aspect, the device for anti-deformation design of an automobile front hood based on CAE simulation according to the present invention includes a controller, and the controller is programmed to execute the above-mentioned method for anti-deformation design of an automobile front hood based on CAE simulation.

[0047] The present invention has the following effects: (1) Through CAE simulation technology, accurately predict and evaluate the deformation risks that may occur during the process of manufacturing the front hood, optimize the structural design and process parameters of the front hood, improve the anti-deformation ability of the front hood, and thus contribute to enhancing the appearance quality of the vehicle.

[0048] (2) Abandon the limitations of traditional methods that rely on experience and trial-and-error in the later stage. By means of systematic analysis, the simulation analysis of the process deformation of the front hood is advanced, avoiding potential appearance quality problems that may occur in the later stage during the early stage of project development, which is conducive to shortening the development cycle, reducing design costs, and has strong engineering application value.

[0049] (3) It can be applied to the anti-deformation ability design of the front hoods of various vehicle models and has wide applicability. Description of the Drawings

[0050] Figure 1 It is a flowchart of the anti-deformation design method for the automotive front hood based on CAE simulation in the embodiment of the present invention.

[0051] Figure 2 It is a schematic diagram of the measuring point positions of the front hood in the embodiment of the present invention.

[0052] Figure 3 It is a schematic diagram for defining the gaps and height differences of the front hood in the embodiment of the present invention.

[0053] Figure 4 It is a specific flowchart of step S2 in the anti-deformation design method for the automotive front hood in the embodiment of the present invention.

[0054] Figure 5 It is a specific flowchart of step S3 in the anti-deformation design method for the automotive front hood in the embodiment of the present invention.

[0055] Figure 6 It is a specific flowchart of step S4 in the anti-deformation design method for the automotive front hood in the embodiment of the present invention.

[0056] Figure 7 It is a flowchart for the simulation analysis of the deformation of the front hood during painting electrophoresis in the embodiment of the present invention.

[0057] Figure 8 It is a specific flowchart of step S5 in the anti-deformation design method for the automotive front hood in the embodiment of the present invention.

[0058] Figure 9 It is a flowchart for the simulation analysis of the deformation of the front hood during painting baking in the embodiment of the present invention.

[0059] Figure 10 It is a specific flowchart of step S6 in the anti-deformation design method for the automotive front hood in the embodiment of the present invention.

[0060] Figure 11This is a schematic diagram of constraints and loading during the local stiffness analysis of the front hood edge in the embodiments of the present invention. Detailed implementation manners

[0061] In order to more comprehensively understand the features and technical content of the embodiments of the present invention, the implementation of the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. The accompanying drawings are only for reference and explanation, and are not used to limit the embodiments of the present invention.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used herein are only for the purpose of describing the embodiments of the present invention and are not intended to limit the present invention.

[0063] In the following description, reference is made to "some embodiments", which describe a subset of all possible embodiments. However, it can be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0064] As Figure 1 shown, the method for designing the anti-deformation of an automobile front hood based on CAE simulation in the embodiments of the present invention includes the following steps: S1. Establish a finite element model of the front hood structure and determine the measuring point positions.

[0065] Specifically: First, import the three-dimensional geometric data of the front hood into the modeling software. The three-dimensional geometric data of the front hood includes the inner panel of the front hood, the outer panel of the front hood, the reinforcement of the front hood, the front hood hinge, etc., as well as the material thickness and material information. Then, perform operations such as geometric cleaning, mesh generation, mesh quality inspection, and material property definition according to the modeling standards to establish a finite element model of the front hood structure, and determine the measuring point positions that need to be concerned at the edge of the front hood (see the measuring point positions from No. 1 to No. 30 in Figure 2 ), and define a coordinate system for measuring the gap and height difference of the front hood at the measuring point positions (see Figure 3 ). Here, the gap refers to the deformation amount of the measuring point position at the edge of the outer panel of the front hood in the X direction of the local coordinate system, and the height difference refers to the deformation amount of the measuring point position at the edge of the outer panel of the front hood in the Z direction of the local coordinate system.

[0066] S2. Select a lifting position on the finite element model of the front hood structure, perform a front hood lifting deformation simulation analysis, and obtain the lifting position when all measuring points meet the first simulation requirements, and use this lifting position as the actual lifting position of the front hood.

[0067] As Figure 4 shown, in some embodiments, S2 specifically includes the following steps: S21. Select a lifting position on the finite element model of the front hood structure, and then execute S22.

[0068] S22. Conduct the simulation analysis of the front cover lifting deformation to obtain the first plastic deformation results of all measuring points, and then execute S23.

[0069] In some embodiments, the first plastic deformation results are characterized by the first gap and the first height difference, that is, when conducting the simulation analysis of the lifting deformation, the first gap and the first height difference of all measuring points will be obtained.

[0070] After the front cover completes the hemming and buckling of the inner panel and the outer panel of the front cover at the hemming die station, it will be lifted and transported. According to the transportation process, it is divided into two types: manual lifting and transportation and robot gripper transportation.

[0071] In some embodiments, the steps of conducting the simulation analysis of the front cover lifting deformation to obtain the first plastic deformation results of all measuring points include: First, apply constraints according to the transportation process: if the transportation process is manual lifting and transportation, then apply constraints to the nodes at the front cover lifting position, specifically restricting the translational degrees of freedom of the nodes at the front cover lifting position in the three directions of the X-axis, Y-axis, and Z-axis; if the transportation process is robot gripper transportation, then apply constraints to the nodes at the gripper clamping part of the robot, specifically restricting the six degrees of freedom in three directions of the clamping part nodes, and the six degrees of freedom are the translational degrees of freedom along the X-axis, Y-axis, and Z-axis and the rotational degrees of freedom around the X-axis, Y-axis, and Z-axis.

[0072] Then, first apply an a-fold gravitational field under the constraints, and then unload the gravitational field, and calculate the first plastic deformation results of all measuring points through simulation analysis. Wherein, a represents a preset first value, a > 1, and as an example, a = 1.6.

[0073] S23. Judge whether the first plastic deformation results of all measuring points meet the (preset) first simulation requirements. If so, execute S25; otherwise, execute S24.

[0074] In some embodiments, the first simulation requirements refer to the requirements for the first gap and the first height difference. If the first gap of all measuring points is less than the preset first gap threshold, and the first height difference of all measuring points is less than the preset first height difference threshold, it means that the first plastic deformation results of all measuring points meet the first simulation requirements.

[0075] S24. Change the lifting position (that is, change the lifting position to a preset position with stronger local structure), and then return to execute S22.

[0076] S25. Take this lifting position as the actual lifting position of the front cover, and then end (that is, complete the simulation analysis of the front cover lifting deformation).

[0077] S3. Select the support positions of the container on the finite element model of the front cover structure, determine the placement method, conduct a simulation analysis on the deformation of the front cover when placed in the container, and obtain the support positions and placement methods of the container when all the measurement points meet the second simulation requirements. Take this support position of the container as the actual support position of the front cover on the container, and take this placement method as the actual placement method of the front cover on the container.

[0078] As Figure 5 shown, in some embodiments, S3 specifically includes the following steps: S31. Select the support positions of the container on the finite element model of the front cover structure, determine the storage method of the container, and then execute S32.

[0079] S32. Conduct a simulation analysis on the deformation of the front cover when placed in the container to obtain the second plastic deformation results of all the measurement points, and then execute S33.

[0080] In some embodiments, the second plastic deformation results are characterized by the second gap and the second height difference, that is, conduct a simulation analysis on the deformation of the front cover when placed in the container to obtain the second gap and the second height difference of all the measurement points.

[0081] In some embodiments, the steps of conducting a simulation analysis on the deformation of the front cover when placed in the container to obtain the second plastic deformation results of all the measurement points include: First, apply corresponding degree-of-freedom constraints to the nodes at the support positions of the container (i.e., the contact area nodes between the front cover and the support part of the container). Specifically, restrict the translational degrees of freedom of the front cover along the X-axis, Y-axis, and Z-axis and the rotational degrees of freedom around the X-axis, Y-axis, and Z-axis at the support part of the container. Before entering the painting and electrocoating process, the front cover is stored in a special container, and the special container is developed and designed according to different project requirements. The front cover is stored and transported through the special container.

[0082] Then, first apply a b-fold gravitational field under the constraints, and then unload the gravitational field. Calculate the second plastic deformation results of all the measurement points through simulation analysis. Here, b represents a preset second value, b > 1. As an example, b = 1.3.

[0083] S33. Determine whether the second plastic deformation results of all the measurement points meet the (preset) second simulation requirements. If so, execute S35; otherwise, execute S34.

[0084] In some embodiments, the second simulation requirements refer to the requirements for the second gap and the second height difference. If the second gaps of all the measurement points are less than the preset second gap threshold, and the second height differences of all the measurement points are less than the preset second height difference threshold, it means that the second plastic deformation results of all the measurement points meet the second simulation requirements.

[0085] S34. Change the placement method and / or move the support position of the container to a preset position with stronger local structure, then return to execute S32. For example: If the initial placement method is horizontal, change it to vertical at this time. When changing, you can only change the placement method, or change the support position of the container at the same time, or only change the support position of the container, but ultimately the second plastic deformation results of all measurement points need to meet the second simulation requirements.

[0086] S35. Take this support position of the container as the actual support position of the front cover on the container, and take this placement method as the actual placement method of the front cover on the container, then end (i.e., complete the deformation simulation analysis of the front cover container placement).

[0087] S4. Select the electrophoresis jig support position and / or optimize the local structure of the front cover on the finite element model of the front cover structure, conduct the deformation simulation analysis of the front cover painting electrophoresis, obtain the electrophoresis jig support position and the finite element model of the front cover structure when all measurement points meet the third simulation requirements, and take this electrophoresis jig support position as the actual support position during the front cover painting electrophoresis.

[0088] As Figure 6 shown, in some embodiments, S4 specifically includes the following steps: S41. Select an electrophoresis jig support position on the finite element model of the front cover structure, and then execute S42.

[0089] There will be a region on the finite element model of the front cover structure that can be used as the support on the electrophoresis jig during electrophoresis. The electrophoresis jig support position is selected within this region. For example, a total of m support positions Ⅰ are preselected within this region, and the electrophoresis jig support position selected in S41 is any one of the m support positions Ⅰ.

[0090] S42. Conduct the deformation simulation analysis of the front cover painting electrophoresis to obtain the third plastic deformation results of all measurement points, and then execute S43.

[0091] In some embodiments, the third plastic deformation results are characterized by the third gap and the third height difference, that is, when conducting the deformation simulation analysis of the front cover painting electrophoresis, the third gap and the third height difference of all measurement points will be obtained.

[0092] As Figure 7 shown, in some embodiments, the steps of conducting the deformation simulation analysis of the front cover painting electrophoresis to obtain the third plastic deformation results of all measurement points include: S421. In the fluid analysis software (such as Star CCM+), according to the (preset) painting electrophoresis flipping process, working conditions, and preset simulation analysis requirements, divide the finite element model of the front cover structure into different postures at equal angles and adjust their postures according to different angles. The front cover painting electrophoresis working conditions are generally divided into Ro-Dip working conditions or double pendulum chain working conditions.

[0093] S422. Calculate the speed of the front cover at different angular postures according to the moving speed of the painting electrophoresis transportation track and the flow rate of the electrophoresis solution. This speed includes the translational speed and rotational speed of the front cover relative to the electrophoresis solution.

[0094] S423. Establish a computational domain, input the preset computational speed, conduct a simulation analysis, and export the electrophoresis impact loads of different postures of the front cover.

[0095] S424. In a structural analysis software (such as ABAQUS), adjust the posture of the finite element model of the front cover structure so that it corresponds one by one to the posture of the finite element model of the front cover structure in the fluid analysis software, and constrain the six degrees of freedom in three directions at the hinge mounting point of the front cover. These six degrees of freedom in three directions are the translational degrees of freedom along the X-axis, Y-axis, and Z-axis and the rotational degrees of freedom around the X-axis, Y-axis, and Z-axis.

[0096] S425. Establish a local coordinate system at the position where the electrophoresis jig supports the inner panel of the front cover. The normal direction of the coordinate system is perpendicular to the plane of the inner panel of the front cover. Under the local coordinates, constrain the normal degree of freedom at the support position of the electrophoresis jig.

[0097] S426. First, apply the electrophoresis impact load and b times the gravitational field under the constraints, and then unload the gravitational field and the electrophoresis impact load. Calculate the third plastic deformation results of all measurement points through simulation analysis.

[0098] S43. Determine whether the third plastic deformation results of all measurement points meet the third simulation requirements. If so, execute S47; otherwise, execute S44.

[0099] In some embodiments, the third simulation requirements refer to the requirements for the third gap and the third height difference. If the third gap of all measurement points is less than the preset third gap threshold and the third height difference of all measurement points is less than the preset third height difference threshold, it means that the third plastic deformation results of all measurement points meet the third simulation requirements.

[0100] S44. Determine whether the current support position of the electrophoresis jig is the preselected last support position I. If so, execute S46; otherwise, execute S45.

[0101] S45. Change the support position of the electrophoresis jig (corresponding to the support hole position of the electrophoresis jig) to the preselected next support position I, and then return to execute S42.

[0102] S46. Optimize the local structure of the front cover, and then return to execute S42.

[0103] In some embodiments, optimizing the local structure of the front cover can be adding ribs or brackets at weak positions, or increasing the cavity size of weak positions, etc.

[0104] S47. Take the support position of the electrophoresis fixture as the actual support position during the front cover painting electrophoresis, and then end (i.e., complete the deformation simulation analysis of the front cover painting electrophoresis).

[0105] S5. On the finite element model of the front cover structure after the deformation simulation analysis of the front cover painting electrophoresis, select the support position of the baking fixture and / or optimize the local structure of the front cover, and conduct the deformation simulation analysis of the front cover painting baking to obtain the support position of the baking fixture and the finite element model of the front cover structure when all measurement points meet the fourth simulation requirement. Take the support position of the baking fixture as the actual support position during the front cover painting baking.

[0106] As Figure 8 shown, in some embodiments, S5 specifically includes the following steps: S51. On the finite element model of the front cover structure after the deformation simulation analysis of the front cover painting electrophoresis (i.e., the finite element model of the front cover structure when all measurement points meet the third simulation requirement in step S4), select the support position of the baking fixture, and then execute S52.

[0107] There will be a region on the finite element model of the front cover structure that can be used as the support on the baking fixture during baking. The support position of the baking fixture is selected within this region. For example, a total of n support positions II are preselected within this region, and one support position of the baking fixture selected in S61 is any one of the n support positions II.

[0108] S52. Conduct the deformation simulation analysis of the front cover painting baking to obtain the fourth plastic deformation results of all measurement points, and then execute S53.

[0109] In some embodiments, the fourth plastic deformation results are characterized by the fourth gap and the fourth height difference, that is, when conducting the deformation simulation analysis of the front cover painting baking, the fourth gap and the fourth height difference of all measurement points will be obtained.

[0110] As Figure 9 shown, in some embodiments, the steps of conducting the deformation simulation analysis of the front cover painting baking to obtain the fourth plastic deformation results of all measurement points include: S521. Obtain the three-dimensional geometric data of the front cover and the drying boundary parameters of the drying chamber.

[0111] In some embodiments, the drying boundary parameters include the room size of the drying chamber, the air outlet wind speed, and the temperature parameters that change with time during the drying process.

[0112] S522. Import the three-dimensional geometric data of the front hood into pre-processing software (such as ANSA) for surface mesh generation to form a surface mesh in STL format. Import the STL-format surface mesh into fluid simulation software (such as Star CCM+) for mesh repair and reconstruction to form a fluid mesh model (which meets the requirements of fluid simulation calculations).

[0113] S523. Determine the simulation space based on the drying boundary parameters of the drying chamber. Adjust the attitude of the fluid mesh model in the software according to the actual drying position and angle of the front hood. Input the wind speed and heating temperature that change with time into the fluid simulation software. Set the initial temperature and drying temperature parameters of the vehicle body. Set the air inlet velocity boundary and the air outlet boundary pressure. Set the fluid calculation time step and iteration threshold. Establish a drying temperature field model for the front hood and conduct fluid simulation calculations to output the temperature field on the surface of the front hood that changes with time.

[0114] S524. In structural analysis software (such as ABAQUS), constrain the six degrees of freedom in three directions of the nodes at the hinge installation points of the front hood.

[0115] S525. Establish a local coordinate system at the support position of the baking fixture. The normal direction of the coordinate system is perpendicular to the plane of the inner panel of the front hood. Under the local coordinates, constrain the normal degree of freedom at the support position of the baking fixture.

[0116] S526. First apply the aforementioned temperature field and b times the gravitational field under the constraints, and then unload the temperature field and the gravitational field. Obtain the fourth plastic deformation results of all measurement points through simulation analysis calculations.

[0117] S53. Determine whether the fourth plastic deformation results of all measurement points meet the fourth simulation requirements. If so, execute S57; otherwise, execute S54.

[0118] In some embodiments, the fourth simulation requirements refer to the requirements for the fourth clearance and the fourth height difference. If the fourth clearance of all measurement points is less than the preset fourth clearance threshold, and the fourth height difference of all measurement points is less than the preset fourth height difference threshold, it means that the fourth plastic deformation results of all measurement points meet the fourth simulation requirements.

[0119] S54. Determine whether the current support position of the baking fixture is the preset last support position II. If so, execute S56; otherwise, execute S55.

[0120] S55. Change the electrophoresis baking support position (corresponding to the support hole position of the baking fixture) to the preselected last support position II, and then return to execute S52.

[0121] S56. Optimize the local structure of the front hood, and then return to execute S52.

[0122] In some embodiments, optimizing the local structure of the front hood can be achieved by adding ribs or brackets at weak positions, or by increasing the cavity size at weak positions, etc.

[0123] S57. Use the support position of this baking fixture as the actual support position during the painting and baking of the front hood, and then end (i.e., complete the simulation analysis of the deformation during the painting and baking of the front hood).

[0124] S6. Based on the finite element model of the front hood structure after the simulation analysis of the deformation during the painting and baking of the front hood (i.e., when all measurement points in step S5 meet the fourth simulation requirement) or after further optimizing the local structure of the front hood, conduct a simulation analysis of the local stiffness at the edge of the front hood. When the local stiffness at the edge of the front hood is greater than the preset stiffness target value, complete the anti-deformation design of the front hood. Obtain a suitable automotive front hood and the process requirements for the manufacturing end. The manufacturing end includes: handling (after the outer panel of the front hood is buckled with the inner panel of the front hood), storing and transporting, painting electrophoresis, and painting baking.

[0125] As Figure 10 shown, in some embodiments, S6 specifically includes the following steps: S61. Based on the finite element model of the front hood structure after the simulation analysis of the deformation during the painting and baking of the front hood, conduct a simulation analysis of the local stiffness at the edge of the front hood to obtain the local stiffness of all loading points, and then execute S62.

[0126] In some embodiments, the steps of conducting a simulation analysis of the local stiffness at the edge of the front hood to obtain the local stiffness of all loading points include: First, remove the front hood hinge and constrain all six degrees of freedom in three directions of all nodes at the edge of the inner panel ring beam of the front hood (see the constrained area outlined in red in Figure 11 ).

[0127] Second, select a loading point at a preset length L interval at the outer edge position of the inner panel of the front hood (see the loading area outlined in blue in Figure 11 ), establish a local coordinate system at the loading point, with the normal direction of the coordinate system perpendicular to the inner panel of the front hood, and then apply a load F along the normal direction of the coordinate system.

[0128] Finally, conduct a local stiffness analysis at the edge of the front hood, output the Z-direction displacement d of all loading points, and use: K = F / d to calculate the local stiffness K of all loading points (i.e., the local stiffness K is equal to the ratio of the load F to the displacement d).

[0129] S62. Determine whether the local stiffness of all loading points is greater than the preset stiffness target value. If so, execute S65; otherwise, execute S63.

[0130] S63. Optimize the local structure of the front hood, and then execute S64.

[0131] In some embodiments, the local structure of the front hood before optimization may be to add ribs or brackets at weak positions according to the deformation nephogram in the simulation results, or to increase the cavity size at weak positions, etc.

[0132] S64. Conduct a local stiffness simulation analysis on the edge of the front hood to obtain the local stiffness of all loading points, and then return to execute S62.

[0133] S65. Complete the anti-deformation design of the front hood, and then end. After completing the anti-deformation design of the front hood, a suitable automotive front hood and manufacturing end process requirements will be obtained.

[0134] In addition, an embodiment of the present invention further provides a device for anti-deformation design of an automotive front hood based on CAE simulation, which includes a controller programmed to execute the above-mentioned method for anti-deformation design of an automotive front hood based on CAE simulation.

[0135] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for anti-deformation design of an automotive front hood based on CAE simulation, characterized in that, Including the steps: S1. Establish a finite element model of the front cover structure and determine the measuring point positions; S2. Select the lifting positions on the finite element model of the front cover structure, conduct a simulation analysis of the front cover's lifting deformation, obtain the lifting positions when all measuring points meet the first simulation requirement, and take this lifting position as the actual lifting position of the front cover; S3. Select the fixture support positions on the finite element model of the front cover structure, determine the loading method, conduct a simulation analysis of the front cover's fixture loading deformation, obtain the fixture support positions and loading methods when all measuring points meet the second simulation requirement, take this fixture support position as the actual support position of the front cover on the fixture, and take this loading method as the actual loading method of the front cover on the fixture; S4. Select the electrophoresis fixture support positions and / or optimize the local structure of the front cover on the finite element model of the front cover structure, conduct a simulation analysis of the front cover's painting and electrophoresis deformation, obtain the electrophoresis fixture support positions and the finite element model of the front cover structure when all measuring points meet the third simulation requirement, and take this electrophoresis fixture support position as the actual support position of the front cover during painting and electrophoresis; S5. Select the baking fixture support positions and / or optimize the local structure of the front cover on the finite element model of the front cover structure after the simulation analysis of the front cover's painting and electrophoresis deformation, conduct a simulation analysis of the front cover's painting and baking deformation, obtain the baking fixture support positions and the finite element model of the front cover structure when all measuring points meet the fourth simulation requirement, and take this baking fixture support position as the actual support position of the front cover during painting and baking; S6. Based on the finite element model of the front cover structure after the simulation analysis of the front cover's painting and baking deformation or after further optimizing the local structure of the front cover, conduct a simulation analysis of the local stiffness at the edge of the front cover. When the local stiffness at the edge of the front cover is greater than the preset stiffness target value, complete the anti-deformation design of the front cover.

2. The automotive hood anti-deformation design method based on CAE simulation according to claim 1, wherein The specific content of step S2 is: First, select the lifting positions on the finite element model of the front cover structure, then conduct a simulation analysis of the front cover's lifting deformation to obtain the first plastic deformation results of all measuring points; if the first plastic deformation results of all measuring points meet the first simulation requirement, then take this lifting position as the actual lifting position of the front cover; Otherwise, change the lifting position and then conduct a simulation analysis of the front cover's lifting deformation until the first plastic deformation results of all measuring points meet the first simulation requirement; Among them, the step of conducting a simulation analysis of the front cover's lifting deformation to obtain the first plastic deformation results of all measuring points includes: First, apply constraints according to the transfer process: If the transfer process is manual lifting and transfer, apply constraints to the nodes at the lifting positions of the front cover; if the transfer process is robot gripper transfer, apply constraints to the nodes at the gripper clamping parts of the robot; Then, first apply an a-fold gravitational field under the constraints, and then unload the gravitational field, and calculate the first plastic deformation results of all measuring points through simulation analysis; a represents a preset first value, and a > 1.

3. The method for anti-deformation design of an automotive front hood based on CAE simulation according to claim 1, wherein The specific steps of step S3 are as follows: First, select the support position of the container on the finite element model of the front cover structure, determine the placement method, and then conduct a simulation analysis on the deformation of the front cover when placed in the container to obtain the second plastic deformation results of all measurement points; if the second plastic deformation results of all measurement points meet the second simulation requirements, then use this support position of the container as the actual support position of the front cover on the container, and use this placement method as the actual placement method of the front cover on the container; otherwise, change the placement method and / or change the support position of the container to a preset position with a stronger local structure, and then conduct a simulation analysis on the deformation of the front cover when placed in the container until the second plastic deformation results of all measurement points meet the second simulation requirements; Among them, the steps of conducting a simulation analysis on the deformation of the front cover when placed in the container to obtain the second plastic deformation results of all measurement points include: First, apply corresponding degree-of-freedom constraints to the nodes at the support position of the container; Then, under the constraint, first apply a b-fold gravitational field, and then unload the gravitational field, and calculate the second plastic deformation results of all measurement points through simulation analysis; b represents a preset second value, and b>1.

4. The method for anti-deformation design of an automotive front hood based on CAE simulation according to claim 1, wherein The specific steps of step S4 are as follows: First, select the support position of the electrophoresis jig on the finite element model of the front cover structure, and then conduct a simulation analysis on the deformation of the front cover during painting and electrophoresis to obtain the third plastic deformation results of all measurement points; if the third plastic deformation results of all measurement points meet the third simulation requirements, then use this support position of the electrophoresis jig as the actual support position during the painting and electrophoresis of the front cover; Otherwise, change the support position of the electrophoresis jig and / or optimize the local structure of the front cover, and then conduct a simulation analysis on the deformation of the front cover during painting and electrophoresis until the third plastic deformation results of all measurement points meet the third simulation requirements; Among them, the steps of conducting a simulation analysis on the deformation of the front cover during painting and electrophoresis to obtain the third plastic deformation results of all measurement points include: S421. In the fluid analysis software, divide the finite element model of the front cover structure into different postures at equal angles according to the painting and electrophoresis flipping process, working conditions, and preset simulation analysis requirements, and adjust their postures at different angles; S422. Calculate the speed of the front cover in different angular postures according to the movement speed of the painting and electrophoresis transportation track and the flow rate of the electrophoresis solution; S423. Establish a computational domain, input the preset computational speed, conduct a simulation analysis, and export the electrophoresis impact loads of different postures of the front cover; S424. In the structural analysis software, adjust the posture of the finite element model of the front cover structure so that it corresponds one by one to the posture of the finite element model of the front cover structure in the fluid analysis software, and constrain the three translational and three rotational degrees of freedom at the hinge installation points of the front cover; S425. Establish a local coordinate system at the position where the electrophoresis jig supports the inner panel of the front cover, with the normal direction of the coordinate system perpendicular to the plane of the inner panel of the front cover, and under the local coordinates, constrain the normal degree of freedom at the support position of the electrophoresis jig; S426. Under the constraint, first apply the electrophoresis impact load and a b-fold gravitational field, and then unload the gravitational field and the electrophoresis impact load, and calculate the third plastic deformation results of all measurement points through simulation analysis; b represents a preset second value, and b>1.

5. The method for anti-deformation design of an automobile front cover based on CAE simulation according to claim 4, characterized in that: If, in the front cover painting electro - deposition deformation simulation analysis based on the current support position of the electro - deposition jig, the third plastic deformation results of all measured points do not all meet the third simulation requirements, then change the support position of the electro - deposition jig to the next pre - selected support position Ⅰ, and then conduct the front cover painting electro - deposition deformation simulation analysis until the third plastic deformation results of all measured points meet the third simulation requirements; If the support position of the electro - deposition jig has been changed to the last pre - selected support position Ⅰ and the third plastic deformation results of all measured points still do not all meet the third simulation requirements, then keep this last support position Ⅰ, and then optimize the local structure of the front cover. After optimizing the local structure of the front cover, conduct the front cover painting electro - deposition deformation simulation analysis until the third plastic deformation results of all measured points meet the third simulation requirements; Take the support position of the electro - deposition jig when the third plastic deformation results of all measured points meet the third simulation requirements as the actual support position during the front cover painting electro - deposition process.

6. The method for anti-deformation design of an automotive front hood based on CAE simulation according to claim 1, wherein, The specific steps of step S5 are as follows: First, on the finite element model of the front cover structure after the front cover painting electro - deposition deformation simulation analysis, select the support position of the baking jig, and then conduct the front cover painting baking deformation simulation analysis to obtain the fourth plastic deformation results of all measured points; If the fourth plastic deformation results of all measured points meet the fourth simulation requirements, then take this support position of the baking jig as the actual support position during the front cover painting baking process; Otherwise, change the painting baking support position and / or optimize the local structure of the front cover, and then conduct the front cover painting baking deformation simulation analysis until the fourth plastic deformation results of all measured points meet the fourth simulation requirements; Among them, the steps of conducting the front cover painting baking deformation simulation analysis to obtain the fourth plastic deformation results of all measured points include: S521. Obtain the three - dimensional geometric data of the front cover and the drying boundary parameters of the drying chamber; S522. Import the three - dimensional geometric data of the front cover into the pre - processing software for surface mesh generation to form a surface mesh in STL format. Import the STL - format surface mesh into the fluid simulation software for mesh repair and reconstruction to form a fluid mesh model; S523. Determine the simulation space based on the drying boundary parameters of the drying chamber. Adjust the attitude of the fluid mesh model in the software according to the actual drying position and angle of the front cover. Input the wind speed and heating temperature that change with time into the fluid simulation software, set the initial temperature and drying temperature parameters of the vehicle body, set the air inlet velocity boundary and air outlet boundary pressure, set the fluid calculation time step and iteration threshold, establish a front cover drying temperature field model, conduct fluid simulation calculations, and output the temperature field of the front cover surface that changes with time; S524. In the structural analysis software, constrain the three - dimensional six degrees of freedom of the nodes at the hinge installation points of the front cover; S525. Establish a local coordinate system at the support position of the baking jig, with the normal direction of the coordinate system perpendicular to the inner plate plane of the front cover. Under the local coordinates, constrain the normal degree of freedom of the support position of the baking jig; S526. First apply the temperature field and b - fold gravitational field under the constraints, and then unload the temperature field and gravitational field. Through simulation analysis and calculation, obtain the fourth plastic deformation results of all measured points; b represents a preset second value, and b > 1.

7. The method for anti-deformation design of the automobile front hood based on CAE simulation according to claim 6, characterized in that: If, in the front hood painting baking deformation simulation analysis based on the current support position of the baking fixture, the fourth plastic deformation results of all measurement points do not all meet the fourth simulation requirement, then change the support position of the baking fixture to the next preselected support position II, and then conduct the front hood painting baking deformation simulation analysis until the fourth plastic deformation results of all measurement points meet the fourth simulation requirement; If the support position of the baking fixture has been changed to the last preselected support position II and the fourth plastic deformation results of all measurement points still do not all meet the fourth simulation requirement, then maintain this last support position II, and then optimize the local structure of the front hood. After optimizing the local structure of the front hood, conduct the front hood painting baking deformation simulation analysis until the fourth plastic deformation results of all measurement points meet the fourth simulation requirement; Take the support position of the baking fixture when the fourth plastic deformation results of all measurement points meet the fourth simulation requirement as the actual support position during the front hood painting baking.

8. The method for anti-deformation design of an automobile front hood based on CAE simulation according to any one of claims 1 to 7, characterized in that, The specific steps of step S6 are as follows: Based on the finite element model of the front hood structure after the front hood painting baking deformation simulation analysis, conduct the local stiffness simulation analysis of the front hood edge to obtain the local stiffness of all loading points; if the local stiffness of all loading points is greater than the preset stiffness target value, then complete the anti-deformation design of the front hood; otherwise, optimize the local structure of the front hood, and then conduct the local stiffness simulation analysis of the front hood edge until the local stiffness of all loading points is greater than the preset stiffness target value.

9. The method for designing the anti-deformation of the automotive front hood based on CAE simulation according to claim 8, wherein, The steps of conducting the local stiffness simulation analysis of the front hood edge to obtain the local stiffness of all loading points include: First, remove the front hood hinge and constrain all six degrees of freedom in three directions of all nodes at the edge of the front hood inner panel ring beam; Secondly, select a loading point at a preset interval L at the outer edge position of the front hood inner panel, establish a local coordinate system at the loading point, with the normal direction of the coordinate system perpendicular to the front hood inner panel, and then apply a load F along the normal direction of the coordinate system; Finally, conduct the local stiffness analysis of the front hood edge, output the Z-direction displacement d of all loading points, and use: K = F / d to calculate the local stiffness K of all loading points.

10. An anti-deformation design device for an automobile front hood based on CAE simulation, including a controller, characterized in that: The controller is programmed to execute the method for anti-deformation design of the automobile front hood according to any one of claims 1 to 9.

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