车身的最优承载度及正向概念设计方法
Optimal Loading Degree and Positive Conceptual Design Method of Car Body

在车身结构正向概念设计阶段，确定最优承载度对指导非承载式纯电动汽车车身轻量化设计具有重要意义。针对模块化的纯电动汽车结构建立了车身的简化几何模型；确定了多点集中载荷作用下非承载式车身承载度与耦合力的函数关系；建立了耦合力作用下车身与车架一致性回传刚度链计算模型；以弯曲刚度为约束条件，以整车质量最轻为目标函数进行优化，得到某款非承载式纯电动汽车的车身与车架各自承受载荷的最优比例及各梁简化截面属性参数。最后利用有限元法建模计算，验证了本文研究方法的合理性和有效性。
Known optimal loading degree is of great significance to guide the lightweight design of pure electric vehicles with body chassis frame construction, at the stage of positive conceptual design. In this paper, a simplified body model is established by reference to a pure electric vehicle with the modular structure. Function relation between loading degree of vehicle with body chassis frame construction under the action of multi-point concentrated load and coupling force is determined. Setting up the calculation model of car body and frame which are both under the action of coupling force by using reverberation-ray matrix stiffness chain, this design method ensures the consistency of the vehicle modeling process. This model considers bending stiffness as constraint conditions and takes vehicle lightweight as objective function for objective optimization, which is solved by using genetic algorithms to get the optimal proportion between body and frame and simplified beam section parameters of vehicle with body chassis frame construction. Finally, the stiffness and loading degree are calculated by using the finite element method, the results proved the rationality and validity of the research method