电动车动力总成有限元建模方法的研究

Research of the Mothed of Finite Element Modeling of an Electric Automotive Powertrain

动力总成作为主要的振动噪声源,成为电动车NVH研究中的关键所在。准确计算动力总成的振动模态和固有频率是降低电动车振动和噪声的基础。分别建立电机和减速器有限元模型,采用4种不同的连接方式,探讨了集中驱动式纯电动车动力总成的有限元建模方法,并分析了点焊单元参数对动力总成有限元固有频率的影响。最后通过对比分析模态锤击试验与有限元计算结果,验证了建模方法的可行性,并结合振动试验结果提出:传动系对动力总成壳体的固有特性存在影响,因此在动响应分析时需考虑传动系的作用。

As one of the major vibration and noise sources of electric vehicle, the powertrain is the key to NVH studies. The accurate calculation of the powertrain vibration modes and natural frequency are the founda- tion of lowering electric vehicle vibration and noise. The finite element model （FEM） of motor and reducer are established and using four different ways of connection, the finite element modeling method of the centralized drive pure electric vehicle powertrain is discussed, meanwhile the effect of spot welding unit parameter on nature frequency is analyzed. Finally, through the comparing and analyzing the calculation result of the modal hammer test and finite element method, the feasibility of modeling method is testified. Combined with the vibration test, it is proposed that the transmission system should be considered in NVH studies since its effect on the inherent characteristic of powertrain shell. The results provided a foundation for the subsequent dynamic response analysis.