Design And Optimization Of Mini Electric Vehicles Body Based On Performance Driven

The body structure of the mini electric vehicle are different form the conventional ones, and this difference will inevitably lead to different development method of body structure. According to the characteristics of the min electric vehicle body miniaturization, lightweight, this paper forms a rapid design and development system process of min electric vehicle body based on performance and lightweight driven by learning the modern car body structure design method and relevant commercial software tools, researching the car body structure design criteria and process based performance driven. An example of a body development of a min electric vehicle body was put into practice, and had achieved good results.The forms of the mini electric vehicles body structure and the lightweight target have been investigated before the body design and development. The mini electric vehicle body topology optimization space is established on the basis of the overall size and modeling. By using equivalent static load method to get displacement average collision force, the nonlinear dynamic condition can be converted to static condition. The topology optimization in typical load cases including various impact condition, top pressure, various stiffness condition for the new mini electric car are carried out to get the main load transfer path of the body. The optimization results show that the front, side, roof, floor and other major areas of the body formed a clear and reasonable topology optimization structure.The geometric wireframe model of the concept frame structure of the body was established on the basis of topology optimization result and design experience. And then the car body model of one-dimensional beam element with section properties was built and the cross-section parameter was optimized to lightweight the car body. According to the optimization result a detailed finite element model was created. The performance of the car body was analysed and evaluated based on FEM method, including torsion stiffness and bend stiffness, along with the level of body lightweight. The result show that the coefficient of lightweight car body was 4.0 which was lower than the target value and met the design requirements. So the method topology optimization and cross-Section parameter optimization for the mini electric car body was feasible and effective.According to characteristics of aluminum can be extruded, optimization design method of aluminum beam section based on the body performance driven was introduced. In view of the unit number of optimization model was large and the low calculation efficiency, the method of super-element which can reduce the non design space out of the model through the static reduction was used. And then using direct matrix input method to optimize the design space. As an example, the front bumper beam has been optimized by using topology optimization of extrusion constraint function. The optimization results show that the optimization efficiency was greatly increased by using super-element. And then two new bumper beam structure was designed on the basis of the optimization results. The pendulum impact simulation analysis was performed and show that these two new-designed bumper beams both have better stiffness and energy absorption performance.