计入曲轴倾斜时曲轴-轴承系统动力学摩擦学和弹性力学耦合分析

Coupling Analysis of Dynamics Tribology and Elastic Mechanics for a Crankshaft Bearing System

采用动力学仿真软件ADAMS和有限元分析软件ANSYS,辅以手工编程相结合的方法,研究了计入曲轴倾斜时某4缸柴油机曲轴-轴承系统动力学、摩擦学和弹性力学(曲轴的刚度和强度)耦合分析问题。根据耦合特点,先解决曲轴-轴承系统动力学、摩擦学和刚度耦合析问题,再解决曲轴动应力计算问题的解耦方法。研究结果表明:计入曲轴颈倾斜,主轴承最小油膜厚度大幅度下降,最大油膜压力大幅度上升,曲轴动力学响应也发生变化,曲轴疲劳寿命下降23.24%。

Multidisciplinary coupling among dynamics, tribology and elastic mechanics （strength and stiffness of crankshaft） of the crankshaft-bearing system of a four cylinder diesel engine was studied by considering the misalignment caused by the elastic deflection of the crankshaft, ADAMS and ANSYS special software were used to solve the coupling problem. A decoupling idea was presented. The coupling between dynamics and tribology was first solved for the elastic crankshaft bearing system and dynamic stress of crankshaft journal surfaces was then calculated by using ANSYS. A special program was designed by the APDL （ANSYS parameter design language）. The results show that the minimum thickness Of oil film decreases and the maximum pressure of oil film increases as the crankshaft misalignment is taken into account, the dynamic response and stress of the crankshaft also vary and fatigue safety coefficient decreases by 23.24 %.