胡望岳1，梁伟强1，孔祥帧1，王志谋2
(1,中国汽车工程研究院股份有限公司，重庆 401122；重庆理工大学，重庆 400054)
摘要：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。本文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。通过一组优化实例我们发现：优化后的白车身一阶扭转频率由32.1Hz 提高到了34.5Hz，一阶弯曲频率由44.2Hz 提高到了46.9Hz，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。
关键词：白车身；模态优化；接头刚度；有限元分析
Abstract: When using the finite element method to optimize the mode of the body-in-white, the large amount of panels will increase the workload of 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 of the body, and to optimize the static stiffness of 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.
Key Words：body-in-white；joints；modal optimization；joint stiffness；finite element analysis
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