基于接头刚度优化的白车身模态优化

Modal Optimization Method of Body-in-White based on Joint Stiffness Optimization

采用有限元方法对白车身模态进行优化时,由于车身中板件数目较多,因而针对模型修改的工作量往往过于庞大且计算周期过长。在传统模态优化方法的基础上,通过模态应变能分析确定车身中的关键接头位置,并以静刚度的优化目标对各关键接头的局部结构进行优化设计,从而提高车身整体的模态频率。通过一组优化实例发现:优化后的白车身一阶扭转频率由32.1 Hz提高到了34.5 Hz,一阶弯曲频率由44.2 Hz提高到了46.9 Hz,且车身质量几乎不变,在保证车身轻量化要求的同时进一步提高了车身的模态性能。

When using the finite element method to optimize the mode ol the body-in-white, the large amount ol panels will increase the workload ol the model modification and computation.On the basis of traditional modal optimization method, this paper uses the modal strain energy analysis to determine the key joints ol the body, and to optimize the static stillness ol each key joint, so as to improve the modal frequency of the body. Through a set of optimization examples it was found that the optimization increased body-in-white first-order torsional frequency from 32.1 Hz to 34.5 Hz, and the first-order bending frequency from 44.2 Hz to 46.9 Hz, while keeping the mass of the body almost unchanged. The optimization further improves the modal performance while still meeting the requirements of the lightweight body.