The Conceptual Design and Development of Body Structure of New Energy Vehicle
|School||South China University of Technology|
|Keywords||new energy vehicles body structure conceptual design and development topology optimization cross-section parameter optimization lightweighting|
The body structure of the new energy vehicles are different from the conventional ones,and this difference will be projected onto the conceptual development method of bodystructure. The conceptual development of new energy vehicle body structure is the key issuein the new energy vehicle development, and it is the research priority of the automotiveindustry and academia. This paper forms a relatively complete and systematic developmentprocesses of new energy body conceptual based on the development process of the modernautomobile body structure and automobile body structure design criteria, using relevantmathematical and commercial software tools. An example of a body conceptual developmentof a new energy vehicle is put into practice, and has achieved good results.Taking the lightweighting as the goal, the forms of the new energy vehicles concept car’sbody structure have been investigated, and the frame structure form is selected. The researchof a vehicle is taken for example to sum up the method of determining the body structuredesign space and the body load on the basis of the layout design, modeling and chassissystems. Methods of multi-body dynamics simulation in typical loadcases for the new energyconcept car are investigated, including modeling, establishing virtual loadcases and definingoutputs, and the resulting data of body load is obtained, which provide the accurate boundaryconditions for the body structure topology optimization. Body structure topology optimizationaims at obtaining the most reasonable load path. Topology optimization is executed for thenew energy vehicle body structure in conceptual design phase based on defining designobjectives, design space and boundary conditions. Some factors affecting the topologyoptimization structure are also discussed in this paper, and some instructive conclusions areobtained through practice on a new energy vehicle: the influence of the penalty factor forgenerating frame concept in topology optimization is investigated and cleared, along with theuse of minimum member size control technology; by investigating the static and dynamicindex weights of topology optimization based on compromise programming approach, therange of weights which can generate legible load paths is cleared. And satisfactory andcredible topology optimization structure is obtained ultimately. A wireframe model of the concept frame structure of the body is created on the basis of topology optimization result,and a finite element model of one-dimensional beam element with section properties is built,the method for cross-section parameter optimization is summed to achieve optimalperformance of the body structure in the constraint of mass.The performance of the body structure conceptual design is analysed and evaluatedbased on FEA method, including body modal, bending stiffness and torsion stiffness, alongwith the level of body lightweighting. The results of the analysis demonstrate that the use ofthe conceptual development method of body structure, which integrating a variety ofoptimization and analysis techniques, is able to provide lightweighting and superiorityconceptual body structure for designers in conceptual design phase. The method is significantfor the future design and optimization of the body structure of the new energy vehicles.