Optimization Of Frame Structure And Experimental Study On Dynamic Performance For A Mini Electric Vehicle

The frame structure is studied with finite element method towards problems of heavy frame weight,short battery life,sub-optimal structure layout and materials distribution.The proposed method could reduce frame weight and increase utilization ratio of body material with sufficient strength and stiffness and well dynamic performance.According to the structure characteristics and layout principle of battery,10 battery layout schemes are proposed in this thesis.The frame structure with each battery layout is studied by static analysis,through which it is found more reasonable with the battery be arranged at the rear part of frame.Furthermore,according to constraint conditions,the load distribution of battery is optimized with battery loads at different location as design variables,and maximum deformation and equivalent stress as target parameters,then the optimal battery layout is obtained.According to deformation and stress distribution under each optimization scheme,the optimal battery layout scheme is selected.Based on determination of the optimal scheme of battery layout,frame mechanical performance is evaluated with finite element analysis to identify the surplus of frame strength and make further improvement towards frame structure.According to results of static analysis and others towards improved frame,improved effect of frame is analyzed,then unreasonable position of beam distribution of frame is found.On the basis of above results,beam spacing is optimized,in which process beam spacing is taken as the design variables,and maximum equivalent stress and others are taken as target parameters.Finally,the most reasonable scheme of beam spacing is given.The optimized frame is analyzed by finite element analysis and experimental verification in different conditions,and the structure optimization effect is evaluated.Based on the optimized frame model,electric vehicle is also manufactured and debugged successively in the workshop and test-analysis laboratory.Finally,the maximum speed,the maximum acceleration and the climbing performance are obtained by power performance analysis of the electric vehicle.