汽车多材料控制臂拓扑优化方法

Multi-material Topology Optimization of Automotive Control Arm

为进一步提高汽车控制臂轻量化水平,提出了一种壳/填充结构多材料拓扑优化方法。采用两组设计变量建立材料插值模型:对第1组设计变量进行两步滤波,利用归一化密度梯度范数将壳区域与填充区域分离;第2组设计变量用于分配填充区域多种材料。为避免填充材料过度聚集,通过映射函数的隐式方法将局部体积约束扩展为多材料填充问题。控制臂优化算例结果表明,材料插值模型能有效识别壳特征和实现局部体积约束,控制臂主体质量较原钢制控制臂减轻13.2%,转向和制动工况下应力水平分别降低55.0%和39.7%,获得较好的轻量化效果。

In order to further reduce the mass of vehicle control arm,a multi-material topology optimization method for shell/filler structure is proposed.Two groups of design variables are adopted to establish the material interpolation model,in which a two-step filtering is conducted on the first group of design variables and the normalized density gradient norms are used to separate shell region and filler region,while the second group of design variables are used for the assignment of multi-material in filler region.To avoid over aggregation of infill material,the local volume constraint is extended to the issue of multi-material filling by implicit mapping function.The results of calculation example of control arm optimization indicate that the material interpolation model can effectively identify the feature of shell and achieve local volume constraints,the mass of the main part of control arm is 13.2%less than the original steel counterpart,and the stress levels in steering and braking conditions are reduced by 55.0%and 39.7%,respectively,getting a better result of lightweighting.