基于多体动力学的发动机稳态工况动态转矩计算

Study on Output Torque of Engine under Condition Based on Multibody Dynamics

理论分析发动机转矩波动产生机理,通过有限元分析得到离散化曲轴模型,建立了滑动轴承动态接触数学模型;协同各子部件间动力学关系,考虑燃气压力、变惯性力等激励载荷,在ADAMS中建立发动机曲轴连杆机构多体动力学模型,仿真计算发动机不同稳态工况下动态转矩,研究曲轴弹性、滑动轴承弹性支承、输出转速等对发动机输出动态转矩的影响.通过试验对比和简谐分析,表明了仿真方法的可行性和准确性,为车辆动力传动系统的扭振分析提供激励条件.

Firstly, the discrete crankshaft model obtained by the finite element method, and dynamic contact mathematic model of slide bearing constructed. Then, the crankshaft mechanism model of some type engine was constructed by adjusting dynamic relationship between pairs of adjacent parts in ADAMS. ombustion pressure and variable inertia force were integrated with this model, and the effects of the flexibility of crank, the flexible support of sliding bearing and engine output speed each on the engine output torque were studied. The model verifies, by contrast study and harmonic analysis, the feasibility and preciseness of the simulation method, which can work as the exciting input for analysis of torsional vibration for vehicle power system.