Research On Multi-objective Lightweight Optimization Design Of Pure Electric Vehicle Body-in-white

Automotive lightweighting has become a key issue in the development of the automotive industry.Automobile lightweighting is of great significance for fuel economy,emission reduction,performance improvement,and healthy development of the automobile industry.It is the direction of modern automobile industry technology development.At present,there are many researches on lightweight technology,but the processes of the theoretical system and the optimization method are not unified and need to be further improved.In this paper,modern design methods such as multi-case optimization and multi-objective optimization are applied,and the lightweight design of the body-in-white is combined with the approximate model and numerical optimization method.The changes of the overall static performance of the body-in-white and the structural parts are optimized.Optimize the impact on the modal performance of the white body.The main research contents are as follows:First,The three-dimensional model of the white body of pure electric vehicle is imported into hypermesh,and its model is simplified properly without affecting the basic performance and changing the important structure.According to the standard of finite element modeling in automobile industry,the numerical model of the white body of pure electric vehicle is built.According to the constraints imposed,the basic performance of the white body of this pure electric vehicle is analyzed.Secondly,on the basis of establishing the finite element model,the mass sensitivity,bending sensitivity,torsional sensitivity and first-order modal sensitivity of most parts of the body-in-white are analyzed,and the relative sensitivity of each component is calculated,and the relative sensitivity is selected.Larger components perform multi-objective optimization in the next chapter,optimizing multi-case dimensions for components with high unidirectional sensitivity.Optimized to effectively reduce the quality of the body-in-white.Thirdly,the selected multi-objective optimized components are designed for optimal Latin hypercube test,and the sample variables of design variables and body-in-white stiffness and modality are collected.On this basis,m ass,torsion,bending and first-order modes are established.The response surface model and cross-validation methods are used to demonstrate the accuracy of the response surface model.The genetic algorithm is used to carry out multi-objective optimization analysis,and the optimization results achieve the weight reduction of the vehicle body on the basis of satisfying the rigid performance and the modal performance.Fourth,the optimized pure electric vehicle body-in-white is tested and the rigid body performance test is carried out on the white body.The test results are compared with the simulation results.The verification results show that the error between the optimized simulation data and the experimental data is within 5%,which proves that the optimization method is feasible and can be applied to the field of lightweight technology.The feasibility of the optimization scheme is further proved.