Compared with the traditional fuel vehicle

the structure of the transmission system of hybrid electric vehicle is more complex

and the torsional vibration of its transmission system under the complex excitation of multiple power sources is more prominent. In this paper

for a P2 hybrid electric vehicle

considering the engine

motor

composite planetary gear mechanism

clutch

reducer

differential and half shaft

the centralized mass model of hybrid electric vehicle transmission system is established with Simcenter AMESim software. On this basis

the natural frequency and vibration mode of the transmission system under different operating conditions are analyzed

and the relationship between the excitation source frequency and transmission system natural frequency is studied. The influence of the first spring stiffness and the second contact stiffness of the clutch on the natural frequency of the transmission system is simulated and analyzed. The stiffness parameters of the clutch are optimized so that the resonant rotating speed of the transmission system is far away from the common working area of the excitation source.