Vehicle body welding spot topological optimization system and method, storage medium and electronic equipment

Abstract

The invention relates to a vehicle body welding spot topological optimization system and method, a storage medium and electronic equipment. The vehicle body welding spot topological optimization system comprises a CAD / CAE module, a topological optimization module, a finite element analysis module and an output module, wherein the CAD / CAE module is used for importing and / or establishing a vehicle body model and simulating the vehicle body model; performing initial performance analysis by using a finite element analysis module; a topological optimization module is used for optimizing a vehicle body structure by applying a topological optimization algorithm; the finite element analysis module performs finite element analysis on the optimized vehicle body structure and verifies the effectiveness and feasibility of an optimization scheme; and the output module outputs the optimized vehicle body structure model and the welding spot layout drawing, and the readable storage medium and the electronic equipment with the program. An existing simulation welding spot optimization method is only used for optimizing the distribution distance or the size of original welding spots of a vehicle body and has certain limitation. Through optimization, not only can the optimal welding spot position be found, but also weak spots of other connection forms can be found, and the performance is enhanced.

Description

Technical Field

[0001] The present invention relates to the fields of software processing and mechanical design and manufacturing, and in particular to a vehicle body welding point topology optimization system, method, storage medium and electronic equipment. Background Art

[0002] Resistance spot welding is the main connection method in car body manufacturing. Usually, a passenger car has thousands of welds throughout the body structure. In mass production, every weld saved can significantly reduce the overall cost. The rationality of the weld arrangement is not only related to the manufacturing cost of the whole vehicle, but more importantly, it is closely related to the various properties of the body structure, such as stiffness, strength, modal frequency and collision resistance. In the past, in the process of body design and manufacturing, the layout of body welds relied to a great extent on the personal experience of engineers and lacked systematic guidance. In order to meet performance requirements, the number of welds was often artificially increased, resulting in redundant welds in some areas of the body, increasing the design and manufacturing costs; on the other hand, the experience-based weld arrangement may lead to insufficient number of welds in some areas of the body, thus failing to give full play to the structure and material properties, resulting in increased materials and costs. More importantly, unreasonable weld arrangement may also lead to excessive local stress in the body, or even connection failure, affecting the safety performance of the whole vehicle.

[0003] And with the rise of new energy vehicles, the market competitiveness and market share of traditional vehicles are constantly shrinking. Reducing energy consumption to achieve energy conservation and emission reduction is a topic of common concern for automobile manufacturers and consumers. For automobiles, the curb weight consumes more than 70% of the output energy of the power system. Therefore, how to effectively reduce the weight of the whole vehicle to achieve the goal of reducing fuel consumption without sacrificing the performance of the vehicle body and without significantly increasing the manufacturing cost of the vehicle is an urgent problem to be solved.

[0004] In view of this, those skilled in the art urgently need to provide a body weld topology optimization system method, storage medium and electronic equipment for reducing the body weight, and provide a weld optimization method to ensure that the impact on the vehicle is reduced while reducing the body weight, thereby ensuring the safety performance of the entire vehicle. Summary of the invention

[0005] The present invention aims to overcome at least one of the shortcomings and deficiencies of the above-mentioned prior art, and provides a body weld topology optimization system, method, storage medium and electronic device. The present invention aims to provide an effective way to achieve lightweight and strength optimization of the body structure by optimizing the body weld layout. The present invention uses computer-aided design (CAD) and finite element analysis (FEA) technology to achieve intelligent optimization of the body weld layout to improve the overall performance and fuel efficiency of the vehicle.

[0006] The purpose of the present invention is achieved based on the following technical solutions:

[0007] In a first aspect of the present invention, a vehicle body weld topology optimization system is provided, comprising a CAD / CAE module for importing and / or establishing a vehicle body model and simulating it, a topology optimization module, a finite element analysis module, and an output module;

[0008] The finite element analysis module calls the simulated body model in the CAD / CAE module, performs an initial performance analysis on the simulated body model and performs a performance analysis on the body model optimized by the topology optimization module to determine the performance after topology optimization;

[0009] The topology optimization module extracts the basic strength, stiffness and mode of the car body model, and performs topology optimization on the car body welding points by setting full welding first and then passing constraints;

[0010] The output module is configured to output the vehicle body structure model and welding point layout drawings optimized by the topology optimization module;

[0011] The CAD / CAE module, the topology optimization module, the finite element analysis module and the output module are communicatively connected.

[0012] Furthermore, it also includes a visualization module, which is used to display the three-dimensional diagram of the CAD / CAE module, the stress distribution cloud diagram and the performance data of the optimization results of the topology optimization module.

[0013] A second aspect of the present invention provides a method for optimizing the topology of a body weld point, using the above-mentioned body weld point topology system, comprising the following steps:

[0014] S1. Establishing a vehicle body structure model: using the CAD / CAE module to establish a three-dimensional model of the vehicle body structure, presenting the geometric shapes and connection relationships of the components, and performing simulation;

[0015] S2. Initial model performance analysis: using the finite element analysis module to perform initial performance analysis;

[0016] S3. Determine optimization objectives and constraints: Determine the topology optimization objectives and constraints of the body weld points according to the design requirements and performance indicators;

[0017] S4. Applying a topology optimization algorithm: optimizing the vehicle body structure by using the topology optimization module and applying a topology optimization algorithm;

[0018] S5. Structural strength evaluation: the finite element analysis module performs finite element analysis on the optimized vehicle body structure, evaluates its strength, stiffness and mode, and verifies the effectiveness and feasibility of the optimization scheme;

[0019] S6. Output optimization results: Output the optimized vehicle body structure model and welding point layout drawings as a reference for production and manufacturing.

[0020] Furthermore, the initial performance includes strength, stiffness and modal index data.

[0021] Furthermore, in step S3, the optimization objective is to minimize at least one of vehicle body weight and flexibility, and the constraint condition is at least one of volume fraction, strength mode and stiffness.

[0022] Furthermore, in step S4, the original welding points are deleted before topology optimization, and full welding is achieved by connecting the nodes with beam unit nodes.

[0023] Furthermore, the topology optimization algorithm includes at least one of a genetic algorithm, a simulated annealing algorithm, or a tanh function.

[0024] Furthermore, in step S3, the evaluation refers to correcting the welding points of the original structural body by analyzing and extracting the best welding point positions, and the correction is based on the minimum layout position while taking into account the improvement of performance to reinforce the weaker performance positions; after reinforcement, the new structural body is imported into the computing storage medium for re-analysis to ensure the reliability of the optimization results.

[0025] According to a third aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and when the instructions are executed by a processor, a method for topological optimization of a vehicle body weld point as described above is implemented.

[0026] According to a fourth aspect of the present invention, an electronic device is provided, comprising at least a processor and a computer-readable storage medium for storing instructions executable by the processor, wherein the processor implements the above-mentioned method for topological optimization of a vehicle body weld point when executing the instructions.

[0027] The existing simulation welding point optimization method only optimizes the distribution spacing or welding point size of the original welding points of the car body, which has certain limitations. The present invention uses topology optimization technology to synthesize the mass and flexibility of the white body as the optimization target, and uses volume fraction, strength mode and stiffness as constraints for topology optimization. The original welding points of the car body are deleted, and the node-to-node full welding setting is adopted for all connection positions of the car body. Through optimization, not only the best welding point position can be found, but also the weak points of other connection forms can be found to enhance performance.

[0028] The present invention utilizes computer-aided design (CAD) and finite element analysis (FEA) technologies, combined with material science and mechanical engineering knowledge, to achieve intelligent optimization of the layout of body welds, so as to improve the overall performance and fuel efficiency of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of a process of a topology optimization method for a vehicle body weld point according to the present invention;

[0030] Figure 2 This is a schematic diagram of the arrangement of welding points of the original structure of the vehicle body according to an embodiment of the present invention;

[0031] Figure 3 It is a schematic diagram of the full welding arrangement position of the vehicle body according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The present invention discloses a vehicle body weld topology optimization system, method and storage medium. Specifically, in a first aspect of the present invention, a vehicle body weld topology optimization system is provided, including a CAD / CAE module for importing and / or establishing a vehicle body model and simulating, a topology optimization module, a finite element analysis module and an output module;

[0034] The finite element analysis module calls the simulated body model in the CAD / CAE module, performs an initial performance analysis on the simulated body model and performs a performance analysis on the body model optimized by the topology optimization module to determine the performance after topology optimization;

[0035] The topology optimization module extracts the basic strength, stiffness and mode of the car body model, and performs topology optimization on the car body welding points by setting full welding first and then passing constraints;

[0036] The output module is configured to output the vehicle body structure model and welding point layout drawings optimized by the topology optimization module;

[0037] The CAD / CAE module, the topology optimization module, the finite element analysis module and the output module are communicatively connected.

[0038] Furthermore, it also includes a visualization module, which is used to display the three-dimensional diagram of the CAD / CAE module, the stress distribution cloud diagram and the performance data of the optimization results of the topology optimization module.

[0039] A second aspect of the present invention provides a method for optimizing the topology of a body weld point, using the above-mentioned body weld point topology system, comprising the following steps:

[0040] S1. Establishing a vehicle body structure model: using the CAD / CAE module to establish a three-dimensional model of the vehicle body structure, presenting the geometric shapes and connection relationships of the components, and performing simulation;

[0041] S2. Initial model performance analysis: using the finite element analysis module to perform initial performance analysis;

[0042] S3. Determine optimization objectives and constraints: Determine the topology optimization objectives and constraints of the body weld points according to the design requirements and performance indicators;

[0043] S4. Applying a topology optimization algorithm: optimizing the vehicle body structure by using the topology optimization module and applying a topology optimization algorithm;

[0044] S5. Structural strength evaluation: the finite element analysis module performs finite element analysis on the optimized vehicle body structure, evaluates its strength, stiffness and mode, and verifies the effectiveness and feasibility of the optimization scheme;

[0045] S6. Output optimization results: Output the optimized vehicle body structure model and welding point layout drawings as a reference for production and manufacturing.

[0046] Furthermore, the initial performance includes strength, stiffness and modal index data.

[0047] Furthermore, in step S3, the optimization objective is to minimize at least one of vehicle body weight and flexibility, and the constraint condition is at least one of volume fraction, strength mode and stiffness.

[0048] Furthermore, in step S4, the original welding points are deleted before topology optimization, and full welding is achieved by connecting the nodes with beam unit nodes.

[0049] Furthermore, the topology optimization algorithm includes at least one of a genetic algorithm, a simulated annealing algorithm, or a tanh function.

[0050] Furthermore, in step S3, the evaluation refers to correcting the welding points of the original structural body by analyzing and extracting the best welding point positions, and the correction is based on the minimum layout position while taking into account the improvement of performance to reinforce the weaker performance positions; after reinforcement, the new structural body is imported into the computing storage medium for re-analysis to ensure the reliability of the optimization results.

[0051] According to a third aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and when the instructions are executed by a processor, a method for topological optimization of a vehicle body weld point as described above is implemented.

[0052] According to a fourth aspect of the present invention, an electronic device is provided, comprising at least a processor and a computer-readable storage medium for storing instructions executable by the processor, wherein the processor implements the above-mentioned method for topological optimization of a vehicle body weld point when executing the instructions.

[0053] Example

[0054] Taking a certain automobile body as an example, the method and system provided by the present invention are used to perform welding point topology optimization. The results show that the weight of the automobile body is reduced by 10% while ensuring the structural rigidity.

[0055] In this embodiment, the stiffness strength and mode of the original structure are first analyzed by using the CAD / CAE module.

[0056] Strength analysis is to select common braking and turning conditions and vertical conditions with relatively severe conditions for analysis, and extract the strength performance of the vehicle body as the subsequent optimization target. The Cartesian coordinate system is used to establish this model. The negative direction of the X-axis is the forward direction of the car, the Y-axis direction is pointing to the right side of the vehicle body, and the Z direction is vertical to the ground and upward. The strength analysis conditions are shown in Table 1.

[0057] Table 1 Basic model strength analysis conditions

[0058]

[0059] Through analysis, the stress distribution and stress statistics under three working conditions are shown in Table 2, among which the maximum stress occurs in the vertical working condition, and the maximum stress is 137.04MPa.

[0060] Table 2 Description of stress calculation results

[0061]

[0062] The bending stiffness and torsional stiffness of the vehicle body are important indicators for evaluating the performance of the vehicle body. The performance of the vehicle body affects the comfort of the driver. Therefore, it is necessary to extract the stiffness of the body in white as an optimization constraint. The front and rear suspension mounting points are captured by RBE2 units respectively. For the bending condition, the translational freedom of the front suspension mounting point of the vehicle body in the X and Y directions is constrained, and the translational freedom of the rear suspension mounting point in the X, Y, and Z directions is constrained. A vertical downward load of 1000N is applied at the intersection of the sill beam and the B-pillar on both sides. For the torsional condition, the translational freedom of the rear suspension mounting point in the X, Y, and Z directions, as well as the translational freedom of the middle Z direction of the front bumper beam are constrained. According to the requirements of automobile companies for the calculation of the torsional stiffness of the vehicle body, a torque of 2000Nm is applied at the front suspension mounting point. The stiffness calculation results are shown in Table 3.

[0063] Table 3 Stiffness calculation results of two working conditions

[0064]

[0065] The resonance of the vehicle body will affect the safety of the vehicle body structure, reduce the NVH performance of the vehicle, and may cause adverse effects such as noise and failure of components. Therefore, it is necessary to pay attention to the natural frequency of the vehicle body to ensure its dynamic performance. The first 9 modes of the vehicle body are set for analysis. Because the analysis type is free mode, the first six modes are rigid displacements, and the natural frequency is close to 0, which can be discarded. The first three natural frequencies are counted, and the statistical results are shown in Table 4. The first-order natural frequency is 35.2Hz, the second-order natural frequency is 40.4Hz, and the third-order natural frequency is 44.1Hz.

[0066] Table 4 The first three natural frequencies

[0067]

[0068] Through the finite element analysis module and the topology optimization module, the initial welding point layout is re-performed. The original structure body welding point layout has not been optimized for its performance and rationality, so it cannot be used as the initial layout position for welding point optimization. Welding points are added on the basis of the initial layout position. The principle of adding welding points is to arrange them as full as possible. The full welding arrangement method can ensure that the best optimized position of welding points is not missing. The original structure body welding point layout position is as follows Figure 2 As shown, full welding layout position Figure 3 shown.

[0069] In order to complete the optimization of the weld, the weld optimization response is set. The response is divided into constraint response and target response. In order to optimize the best weld distribution and weight reduction, it is necessary to set the constraint response for the overall volume fraction of the weld. Select the volume fraction type in responses, and set the upper bound to 0.3 in the deconstraints volume response, that is, the volume constraint is 30% of the original volume fraction. At the same time, the constraint response needs to comprehensively consider the stiffness, strength and modal performance of the whole vehicle. Therefore, the flexibility of the whole body and weld is set as the optimization response.

[0070] After completing the setting of the solder joint response, the corresponding constraints and targets need to be set. Reasonable solder joint distribution needs to take into account the optimal performance with the least number of solder joints, so the volume fraction setting needs to be reasonable. Based on the research on the same platform model, the 30% volume fraction constraint is the best constraint value, and the volume fraction is set according to this value. In order to ensure the best performance of the optimization process, the objective function selects flexibility minimization.

[0071] Intelligent optimization is performed through the topology optimization module. The optimization process is transferred into the intelligent optimization module to accelerate the optimization speed and improve the optimization accuracy. The optimization process uses a three-layer neural network and calls the tanh function for intelligent optimization. The training data is collected from the same platform model.

[0072] The optimization results are extracted again through the finite element analysis module. After completing the relevant settings, the calculation storage medium is submitted for calculation of the optimization process, and the calculation results are analyzed. The initial welding point layout is spread throughout the entire body. The analysis results show the importance of welding point distribution through the distribution of welding point density. The welding points of the original structural body are corrected by analyzing and extracting the best welding point positions. The correction is based on the minimum layout position as a reference while taking into account the improvement of performance to strengthen the weaker performance positions. After reinforcement, the new structural body is imported into the calculation storage medium for re-analysis to ensure the reliability of the optimization results.

[0073] Results comparison. After the model rearranged the welding points, the three working conditions of braking, turning, and vertical downward were re-analyzed. The comparison with the basic model results is shown in Table 5. The stress of the braking condition was reduced by 14.35MPa, and the performance was improved by 57%. The turning condition was reduced by 13.33MPa, and the performance was improved by 40%. The maximum stress (vertical condition) was reduced by 45.68MPa, and the strength was increased by 33%.

[0074] Table 5 Comparison of stress results of three working conditions before and after optimization

[0075]

[0076] According to the constraints and load settings of the initial model, the stiffness performance of the new structure was re-verified. The results are summarized in Tables 6 and 7. In comparison, the first-order modal natural frequency increased by 6Hz, and the modal increased by 17%. The bending stiffness increased by 10009N / mm, and the bending stiffness performance increased by 11%. The torsional stiffness increased by 24000Nmm / °, and the torsional stiffness performance increased by 23.4%. By comparing the total mass of the front and rear bodies, it can be found that after optimizing the layout of the welding points, the body weight is reduced by 5% and the fuel efficiency is improved by 4%.

[0077] Table 6 Comparison of the first three natural frequencies

[0078]

[0079] Table 7 Stiffness calculation results of two working conditions

[0080]

[0081] Traditional weld optimization mostly only optimizes the number of existing welds or the spacing between welds, which limits the optimization space and the scope of performance improvement. The present invention introduces topology optimization technology into the optimization layout of welds, defines the optimization object to the full-body welds, combines structural lightweight methods and material lightweight methods, and optimizes under the premise of ensuring the performance of all aspects of the body. Through reasonable weld arrangement, in terms of performance, the first-order modal modal natural frequency is improved by 17%. The bending stiffness is increased by 11%, and the torsional stiffness is increased by 23.4%. The maximum stress (vertical working condition) is reduced by 45.68MPa, and the strength is increased by 33%. In terms of body weight, reducing the overall weight of the body by 10% can improve fuel efficiency by about 8%.

Claims

1. A car body weld point topology optimization system, characterized in that: Includes CAD / CAE modules for importing and / or building vehicle body models and simulation, topology optimization modules, finite element analysis modules, and output modules; The finite element analysis module calls the simulated body model in the CAD / CAE module, performs an initial performance analysis on the simulated body model and performs a performance analysis on the body model optimized by the topology optimization module to determine the performance after topology optimization; The topology optimization module extracts the basic strength, stiffness and mode of the car body model, and performs topology optimization on the car body welding points by setting full welding first and then passing constraints; The output module is configured to output the vehicle body structure model and welding point layout drawings optimized by the topology optimization module; The CAD / CAE module, the topology optimization module, the finite element analysis module and the output module are communicatively connected.

2. A vehicle body weld point topology optimization system according to claim 1, characterized in that: It also includes a visualization module, which is used to display the three-dimensional diagram of the CAD / CAE module, the stress distribution cloud diagram and the performance data of the optimization results of the topology optimization module.

3. A method for topological optimization of a car body weld point, characterized in that: The vehicle body welding point topology system according to claim 1 or 2 comprises the following steps: S1. Establishing a vehicle body structure model: using the CAD / CAE module to establish a three-dimensional model of the vehicle body structure, presenting the geometric shapes and connection relationships of the components, and performing simulation; S2. Initial model performance analysis: using the finite element analysis module to perform initial performance analysis; S3. Determine optimization objectives and constraints: Determine the topology optimization objectives and constraints of the body weld points according to the design requirements and performance indicators; S4. Applying a topology optimization algorithm: optimizing the vehicle body structure by using the topology optimization module and applying a topology optimization algorithm; S5. Structural strength evaluation: the finite element analysis module performs finite element analysis on the optimized vehicle body structure, evaluates its strength, stiffness and mode, and verifies the effectiveness and feasibility of the optimization scheme; S6. Output optimization results: Output the optimized vehicle body structure model and welding point layout drawings as a reference for production and manufacturing.

4. A method for topological optimization of a body weld point according to claim 3, characterized in that: In step S2, the initial performance includes strength, stiffness and modal index data.

5. The method for topological optimization of a body weld point according to claim 3, characterized in that: In step S3, the optimization objective is to minimize at least one of vehicle body weight and flexibility, and the constraint condition is at least one of volume fraction, strength mode and stiffness.

6. The method for topological optimization of a body weld point according to claim 3, characterized in that: In step S4, the original welding points are deleted before topology optimization, and full welding is achieved by connecting the nodes with beam units.

7. The method for topological optimization of a body weld point according to claim 3, characterized in that: The topology optimization algorithm includes at least one of a genetic algorithm, a simulated annealing algorithm, or a tanh function.

8. The method for topological optimization of a body weld point according to claim 3, characterized in that: In step S3, the evaluation refers to correcting the welding points of the original structural body by analyzing and extracting the best welding point positions, and the correction is based on the minimum layout position while taking into account the improvement of performance to reinforce the weaker performance positions; after reinforcement, the new structural body is imported into the calculation storage medium for re-analysis to ensure the reliability of the optimization results.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and when the instructions are executed by the processor, a method for topological optimization of a vehicle body weld point according to any one of claims 3 to 8 is implemented.

10. An electronic device, characterized in that: The method comprises at least a processor and a computer-readable storage medium for storing instructions executable by the processor, wherein when the processor executes the instructions, a method for topological optimization of a vehicle body weld point according to any one of claims 3 to 8 is implemented.

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