Analytical Investigation On Multi Body Dynamics Of Crank Train Based On A Virtual Engine Module

Internal combustion engine designs are continuously moving towards increased engine power, reduced engine size and improved fuel economy, simultaneously. Also,efforts to reduce engine vibration and radiated noise while improving durability and reliability have become increasingly important in the automotive industry due to requirements for high performance, low weight, low cost and fast-to-market engine designs. Proceeding to the vibration caused by engine, the thesis points out the significance of the dynamic investigation of engine crank train with virtual design technology. Take X6170ZC diesel engine as an example, the key steps and approaches of the virtual design of engine crank train are discussed according to the status and methodologies of investigation on engine noise. The main points of the thesis are as follows:Firstly, the paper describes the applications of virtual design in I.C. engine industry. It is concluded that virtual design will be the trend of modern I.C. engine design method.Secondly, the thesis conducts the Finite Element Modal Analysis on the crankshaft of X6170ZC diesel engine to find out the natural frequencies and modal shapes of them. The FE models of the crankshaft are the basis of the dynamics analysis of the crankshaft system. And then, the Experimental Modal Analysis (EMA) is conducted in this thesis to determine some parameters, such as the natural frequencies, modal shapes and modal damping of the crankshaft and engine block to verify the veracity of their FE models. By comparing the FEA results to EMA data, it is concluded that the FE models of the crankshaft and engine block are able to meet the needs of engineering demand.It is important for virtual experiment to create a suitable and efficient Virtual Engine Module for a complex system. The part models have different levels of detailing with respect to different simulation targets. These improve the engine development process by increasing the quality and reducing the process time. The paper describe a process of create a suitable virtual engine module.Through the dynamics simulation of the flexible crankshaft system, the torsional vibration, dynamic stress and fatigue factors of safety are predicted. Torsional vibration predictions were then compared to actual dynamic measurements of the...