基于多体动力学的柴油机结构表面振动研究分析

Research and Analysis of Diesel Engine Structure Surface Vibration Based on Multi-body Dynamics

以云内动力某型号柴油发动机为研究对象,建立曲轴、活塞、连杆体组成的多体动力学模型,根据发动机额定工况下的示功图得到发动机一个工作循环周期的气体爆发压力函数,计算得到一个工作周期内的曲轴主轴承受力时间载荷。建立简化后的发动机整机模型,以多体动力学计算得到曲轴主轴承受力时间载荷为激励源,采用有限元的方法进行机体结构表面振动分析,得到机体表面振动强弱的分布,为柴油机的低振动设计提供改进意见。

Taking a diesel engine of Yun inner power as the research object, a multi-body dynamic model consisting of crankshaft,piston and connecting rod body is established. According to the dynamometer diagram of the engine under the rated working condition, the gas burst function of a working cycle of the engine is obtained, and the time load of the bearing force of the crankshaft is calculated in a working cycle. A simplified engine model is established, and the bearing force and time load of crankshaft are excited by multi-body dynamics. The finite element method is used to analyze the surface vibration of the body structure, and the distribution of the surface vibration intensity of the body is obtained. The purpose of this paper is to provide suggestions for improvement of low vibration design of diesel engine.