基于梁截面几何特性参数的白车身结构优化设计

Optimization of car-body structures based on the characteristic parameters of beam structures

文章建立了基于梁截面几何特性参数的参数化车身概念模型,提出车身刚度相关性系数对梁与壳单元转换产生的精度误差进行修正。同时,引入Kuhn-Tucker约束条件,以梁的质量最小值为目标函数,车身弯曲、扭转刚度目标值为约束函数,输出最优的梁截面几何特性参数结果,进而确定截面形状及其几何尺寸。另外,对各车身梁结构的性能贡献度进行了分析,在满足车身扭转、弯曲刚度性能目标的基础上,对参考车型结构进行优化,使得车身减重36.4kg,减轻率为11.9%。

In this paper the parametric technique is utilized for the conceptual design and optimization of car body with stiffness analysis.According to the finite element theory the reference car body is parameterized using beam elements.The correlation coefficient of stiffness is defined to modify the precision of computational model.In the optimization process,the minimum mass is defined as objective function,values of the flexural and torsional stiffness are regarded as the constraint functions.Then,with the Kuhn-Tucker condition the optimal parameters of geometric characteristic can be obtained for the determination of shapes and sizes of beam cross sections.Besides,the effect of beam structures on performances of car body is analyzed in detail and after the optimization the mass decreases by11.9%(36.4kg).