3.3综合方案模态分析

将优化方案一与优化方案二综合，并计算模态。得到副车架上悬置支架第一阶模态频率为205.6Hz。其模态阵型图如图5所示。

4优化前后结果对比

通过结构优化，副车架上悬置支架第一阶模态频率从157.4Hz提高到205.6Hz，满足200Hz目标值。达到了副车架、悬置支架与发动机避频的目的。

5结论

本文通过HyperWorks中的HyperMesh建模，Hypermoph网格变形，HyperView后处理。将副车架上悬置支架一阶模态频率从157.4Hz提高到205.6Hz，增幅为48.2Hz，使其满足目标值，大大降低了副车架、悬置与发动机产生共振的风险，解决了由此类原因导致的振动噪声问题，保证了驾驶员与乘客的舒适性。通过CAE技术，为产品设计部门提供强有力的设计依据。

6参考文献

[1]庞剑，等．汽车噪声与振动．北京理工大学出版社 .2006

[2]张胜兰，等．基于HyperWorks的结构优化设计技术 . 机械工业出版社

[3]傅志方，等. 模态分析理论与应用 . 上海交通大学出版社

Modal Analysis and Optimization of a Subframe Base on HyperWorks

Chen Hua      Feng Yunxiu

Abstract:  Subframe is one of the important factors in comfort for vehicle.The frequency value of the first mode must be higher than the quadratic frequency value which engine induced, in order to avoiding sympathetic vibration between subframe and engine.In this paper, the first mode is analysed and optimized to satisfied target value, as well as reducing the risk of NVH based on subframe of a certain automobile using HyperWorks.

Key words: subframe   sympathetic vibration   mode