中文摘要：

对发动机曲轴系统的扭振特性进行了理论分析，利用GT-Crank模块建立某V型6缸发动机的动力学仿真模型，对发动机单缸断油和单缸关闭气门两种工况进行仿真计算，对比分析了发动机正常发火与单缸停缸时系统扭振特性。仿真结果表明：单缸停缸时系统扭振以低谐次为主，扭振振幅较正常发火显著增加，扭转应力变化不明显；单缸关闭气门扭振振幅较单缸断油大；不同气缸断油和关闭气门扭振振幅最大差距分别为16．5％和4．3％。

英文摘要：

The torsional vibration characteristics of engine crankshaft system were theoretically analyzed. Then dynamics sim- ulation model of a V-6 engine was established with the GT-Crank module. Based on the model, the fuel cutoff and valve closing of a single cylinder was simulated. The system torsional vibration characteristics between normal combustion and single cylinder misfire were compared. The results show that, when one cylinder stops working, the system torsional vibration mainly occurs on low harmonic orders, the vibration amplitude obviously increases, but the torsional stress hardly changes. Compared with the fuel cutoff , the valve closing for a single cylinder has greater influence on torsional vibration. The maximum amplitude differences of fuel cutoff and valve closing for different cylinders are 16.5% and 4.3% respectively.