基于灵敏度分析的车门尺寸和拓扑优化

Size and Topology Optimization of Car Door Based on Sensitivity Analysis

为了改善微型车X30的车门在使用过程中振动过大这一问题,利用Hypermesh建立该车车门的有限元模型,并对其进行模态分析。分析结果发现车门的一阶频率偏低,容易与白车身一阶弯曲频率发生共振。因此,基于灵敏度分析方法结合尺寸优化和拓扑优化方法对车门进行以提升车门一阶模态频率为目标的优化设计。首先,对车门各零部件进行质量灵敏度和一阶模态频率灵敏度分析,并定义相对灵敏度值;然后,根据相对灵敏度值结果选择合适的设计变量进行部件厚度的尺寸优化设计;最后,基于变密度法对相对灵敏值最大的部件进行拓扑优化,根据优化结果对该部件有限元模型进行修改。结果表明,在车门质量减少4.5%的情况下,车门一阶模态频率提高8.9%,有效地改善了车门的振动情况。

In order to improve the vibration problem of the micro car X30 in the using process,the finite element model of the door was built in Hypermesh and modal analysis was carried on the door. The analysis results showed that the first-order frequency of the door was low,which would easily resonate with first-order bending of the body. So,on the basis of the sensitivity analysis method combined with size optimization and topology optimization method to improve the first-order modal frequency of the door. First,the mass sensitivity and first order modal frequency sensitivity analysis were carried on the parts of the door,and defined the relative sensitivity values of every part. Then according to the relative sensitivity value to select appropriate components as the design variables of the size optimization design. Finally,the topology optimization that based on variable density method was used on one of the part of the door,which had the highest relative value. According to the result to modify the finite element model of the component. The results showed that under the premise of door quality decrease by 4. 5%,the first order modal frequency of the door was increased 8. 9%. This method effectively improves the vibration performance of the door.