Lightweight Design And Research Of Based On Stell-aluminum Hybrid Electric Vehicle Body Skeleton

With the continuous increase in the number of automobiles worldwide,energy issues and environmental issues will become more prominent.In order to curb the intensification of the problem,most countries in the world,including China,have begun to vigorously develop electric vehicles.For the time being,battery life is still a key issue that urgently needs to be solved for electric vehicles.Before the car battery can not achieve a major breakthrough,the lightweight body is undoubtedly the most powerful way to improve the mileage of electric vehicles.In this paper,a UTV body skeleton was taken as a prototype to achieve the goal of obtaining the electric car body skeleton that meets the requirements of highway road conditions,through the optimization of structure and the application of steel and aluminum materials to achieve a light、weight body frame,fully reduced the weight of the body frame to improve the cruising range of he electric vehicles.Firstly,based on the UTV solid body skeleton to build its three-dimensional model and finite element model,the basic performance analysis of the car body skeleton was conducted respectively under four conditions:bending conditions,torsional conditions,steering conditions,braking conditions and intrinsic modes.Then,based on the theory of continuum topology optimization of the variable density method,the topological optimization of the finite element model was performed,and the body skeleton structure was improved according to the topology optimization results.Then the sensitivity of all the members of the body frame was analysed.According to the sensitivity,choose the members that can increase and decrease the thickness,and obtain the optimal thickness of each member from the results of the size optimization.Finally,according to the results of topology optimization and size optimization,the finite element model of the structure-optimized body skeleton was reconstructed,and the basic performance analysis of the structure optimized model was performed,and compared with the former.In order to realize the replacement of steel and aluminum materials,according to the actual situation of the body frame,a steel-aluminum joint was designed to realize the connection between the steel and aluminum bar parts transformed into the connection between the steel and aluminum plate parts,and the connection between the connectors and the steel and aluminum members was achieved by welding and bolting.After that,a separate connection strength analysis was performed on this joint connection,and concluded that it satisfies the connection strength requirements,and the basic performance analysis was performed on the entire body frame after this joint was applied.Finally,the results show that the performance of the steel-aluminum hybrid vehicle body skeleton still meets the requirements.Through the comparison of the basic performances before optimization,after optimization,and after material replacement,it can be determined that the final steel-aluminum hybrid body frame achieves the goal of lightweighting while ensuring the overall stiffness performance.The overall weight reduction of the frame is 22.7%,achieving the set target.