Abstract: Because the front sub frame is connected with the engine through the engine rear mount, in the design should not only consider the strength, at the same time, in order to avoid the vibration amplification and noise, improve the performance of NVH, must made modal characteristics as necessary constraints on the front sub frame design, to avoid the vibration frequency of engine in different revolving speeds (midband: 25 Hz~400 Hz), and to avoid the driving frequency of the road (low frequency band:<25 Hz). In this paper use front sub frame of a new MPV as an example, using finite element software ABAQUS to analysis the mode of front sub frame, and combined with the test data to verify the accuracy of the CAE model, provide the CAE analysis basis for the design and improvement of the front sub frame.

Key words: Sub frame, Mode analysis, Modal characteristics, ABAQUS

摘要： 由于前副车架通过发动机后悬置与发动机相连,在设计时不仅要考虑到其强度,同时为了避免振动放大和噪声,提升NVH性能,必须将模态特征作为对前副车架设计的必要约束条件,避开发动机在各转速下的激振频率（中频：25 Hz~400 Hz）,也要避开路面的激励频率（低频：25 Hz以下）。文章以某公司某款全新MPV的前副车架为例,运用有限元软件ABAQUS对前副车架进行模态分析,并结合试验数据验证CAE模型的准确性,为乘用车前副车架的设计和改进提供了CAE分析依据。

关键词: 副车架, 模态分析, 模态特征, ABAQUS