Research On Ev Battery Box Equal Stiffness And Lightweighting Considered With Response Surface

The automobile is a product of modern civilization,the development of automobile is also accompanied by human society concerns: shortage of energy and pollution of environment.The development of electric vehicles is advancing step by step.Although electric vehicle has developed rapidly in the past 20 or 30 years.However,there are still some technical problems,such as battery,motor control and other technologies,these lead to electric vehicles with poor safety,low stability,high cost,short driving range without the technological breakthrouths.Therefore,it is important to research the problem of lightweight electric vehicle in theory and practice before the key technologies breakthrough.As the carrier of the battery pack on the electric vehicle,the battery box is important to the safety and protection of the battery pack.At present,the battery box is made of welded steel,the overall quality is a little heavy,it can increase the driving mileage of the electric vehicle in the case of lightweighting the battery box.In previous studies,the structure of the battery box was generally optimized,and the equal stiffness of the battery box considered with response surface was less studied.Therefore,the paper based on the National & International Scientific and Technological Cooperation Special Project(2014DFA80440),the battery box of a certain electric vehicle is studied.Using the theory of equal stiffness to carry on the material replacement lightweight research to the battery box considered with response surface.Three dimensional solid model and finite element model of battery box are established,lay the foundation for subsequent performance analysis.The finite element analysis software is used to analyze the performance and mode of battery box under three working conditions,such as sharp turn,brake and bumpy road,According to the analysis,selected the main components of battery box for lightweighting.The concept of material index is put forward which is explaining the rationality of material replacement.According to the approximate formula of equal stiffness theory,the range of thickness of battery box parts after material replacement is calculated.For further optimization,according to the stiffness sample values of battery box under sharp turning,braking,bumpy and modal conditions,the response surface model of five component thickness variables of battery box is established,which is used to replace the original finite element model to participate in optimization.Taking the mass and modal frequency of the aluminum alloy battery box as the objective function,taking the threeworking condition displacement as the constraint conditions,the multi-objective optimization design of the battery box is carried out,and the optimal solution is selected.The simulation results show that the aluminum alloy battery box conforms to the standard.