基于多学科优化的多用途货车白车身轻量化设计

BIW Lightweight Design of Multi-Purpose Truck Based on Multidisciplinary Optimization

为探究多用途货车车身轻量化设计空间,在性能、质量、成本间进行多学科优化,以某多用途货车白车身为研究对象,选取46个设计变量,涵盖73个零件厚度水平的1680个样本点,采用最优拉丁超立方方法进行弯扭刚度、模态频率、质量、成本的试验设计,得到零件对车身性能贡献的灵敏度,建立二阶多项式响应面近似模型。具体制定3组优化方案,分别为保持原车身基础性能水平,允许刚度下降10%、模态频率波动2Hz,允许刚度下降20%、模态频率波动4Hz,利用自动优化算法以质量最小为目标进行优化设计。结果表明,3组优化方案分别可减轻质量14.63kg、20.37kg、25.78kg。

In order to explore the lightweight space of multi-purpose truck body,multidisciplinary optimization was carried out in three dimensions of performance,quality and cost.With the multi-purpose truck Body-In-White(BIW)as the research object,46 design variables were selected,covering 1680 sample points at 73 part thickness levels,and the optimal Latin hypercube method was used to conduct the experimental design of bending torsional stiffness,mode frequency,mass,and cost,to obtain the sensitivity of the part’s contribution to the BIW performance,and to establish a second-order polynomial response surface approximation model.Specifically,three groups of optimization solutions were formulated to maintain the basic performance level of the original body,the allowable stiffness decreased by 10%,and the modal fluctuation was 2 Hz;the allowable stiffness decreased by 20%,and the modal fluctuation was 4 Hz.The Pointer automatic optimizer was used to optimize the design with the minimum mass as the objective function.The results show that three optimization solutions can reduce the mass by 14.63 kg,20.37 kg and 25.78 kg respectively.