【作者】 程晓鸣；

【导师】 张俊红；

【作者基本信息】 天津大学 ， 动力机械及工程， 2006， 硕士

【摘要】 内燃机设计正朝着高性能,轻量化、低油耗的方向不断发展。随着人们对高性能、轻量化、低成本及高市场适应能力发动机的不断追求,对发动机减振、降噪、可靠性等方面的研究变得越来越重要。本文以发动机轴系扭振控制为出发点,指出了应用虚拟技术开展发动机轴系动力学研究的重要意义,以X6170ZC型柴油机为例,探讨了内燃机轴系虚拟开发设计的主要研究步骤和方法。本文主要内容如下:首先阐述了虚拟技术在内燃机领域的应用,指出了虚拟设计将是内燃机现代设计的方向。以有限元动态特性分析为基本手段,对X6170ZC型柴油机的曲轴进行了有限元模态分析,掌握了该机曲轴的固有频率和振型,为曲轴运动件系统动力学分析奠定了基础。为了校验曲轴有限元模型的准确性,从实验研究的角度出发,对曲轴进行了振动模态实验研究。实验结果和有限元分析结果对比表明,本文建立的有限元模型能够满足工程设计和分析的要求。对于复杂系统而言,如何建立一个有效、恰当的虚拟样机模型是进行虚拟试验考核的关键,指出针对不同的分析目标需要建立不同分析层次的虚拟样机模型,减少工作量,节省时间,增加研发速度。针对本文的研究目的建立了一个有效的曲轴系统动力学分析的虚拟样机。通过对运动件系统进行柔性多体动力学计算,分析了曲轴的扭转振动、动态应力和疲劳安全系数等问题,通过计算得到的扭振数据与实验数据吻合较好。针对该轴系扭振振幅较大的问题,进行扭振器匹配的虚拟试验研究,提出了改进方案。并对改进后的轴系进行了扭振特性的研究,取得了一定的减振效果。更多还原

【Abstract】 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更多还原