发动机曲轴扭振仿真及振动控制研究

发布时间：2018-01-07 23:32

本文关键词：发动机曲轴扭振仿真及振动控制研究　出处：《中北大学》2016年硕士论文　论文类型：学位论文

【摘要】：发动机作为主要的动力机械之一,广泛应用于船舶、汽车、机车等交通工具和工程机械。随着发动机动力性、可靠性要求的不断提高,发动机曲轴系的工作条件也更加苛刻,其强度、振动等问题也因此变得更加突出和重要,并逐渐成为发动机仿真分析和设计计算的重点和难点。传统的发动机设计和分析方法难以满足实际的设计需要。所以本文运用三维建模技术、有限元法和多体系统动力学仿真技术等先进方法和技术对发动机曲轴系统的动力学和扭振特性进行仿真分析,并对扭振减振进行了深入的研究,具体的研究内容如下:1、利用Catia软件对曲轴系的主要零部件进行了三维实体建模,其中包含曲轴、连杆、活塞、飞轮等,并完成了自底向上的虚拟装配。并利用有限元软件的模型分析功能确定了所建立实体模型的材料特征参数和质量特征参数;然后将建立的的三维实体模型体导入到ADAMS软件里,并且在零部件间施加适当的约束,最终得到多刚体动力学分析模型。2、利用有限元分析理论,研究了两种发动机飞轮不同处理方式对整体动态性能和曲轴轴系柔性化处理结果的影响。即在Ansys workbench软件中建立发动机曲轴轴系的有限元模型,包含飞轮质量单元的轴系有限元模型和包含飞轮实体有限元模型的轴系有限元模型,在分别对这两种有限元模型进行动态特性分析的基础上,对比分析了采用飞轮质量单元和飞轮实体单元对整体动态性能的影响。3、在Adams软件中将刚性体发动机曲轴替换为柔性体发动机曲轴,得到发动机曲轴的刚柔混合模型。对刚柔混合模型进行了运动学和动力学仿真分析,在获得活塞的运动学特性曲线和曲柄销、活塞销等零部件的动力学特性曲线的基础上,进而对发动机曲柄连杆机构的动力学特性进行了分析与评价。4、利用Ansys Workbench软件和Adams软件对曲轴轴系在不同转速工况下进行了强迫扭转振动仿真分析,得出曲轴自由端和飞轮端的扭振时域响应和频域响应。进一步对时域响应和频域响应进行分析,结果表明曲轴会产生明显的一阶扭转共振,应当予以重视。5、深入研究了发动机曲轴扭转振动控制方法与措施,结合发动机曲轴自由端扭转振动仿真分析结果和减振器设计理论,详细设计了减振器,并通过对比分析设计减振器前、后曲轴轴系强迫振动仿真结果验证了曲轴扭转减振器的有效性。同时,还通过调整轴系的固有频率和输入系统的扭振能量来研究其对扭转振动的影响。
[Abstract]:As one of the main engine power machinery, widely used in ships, automobiles, locomotives and other vehicles and construction machinery. With the engine power and reliability requirements to improve the working conditions of engine crankshaft are more demanding, the strength and vibration problem has become more prominent and important, and gradually become the focus and difficulty simulation analysis and design calculation of engine. The engine design and analysis of the traditional method cannot meet the actual needs of the design. So this paper uses the technology of 3D modeling, finite element method and multi-body system dynamics simulation technology and other advanced methods and techniques for simulation analysis of engine crankshaft system dynamics and torsional vibration characteristics of torsional vibration damper is studied, the specific contents are as follows: 1. Using Catia software the main components of the crankshaft system of 3D solid modeling, the Contains the crankshaft, connecting rod, piston, flywheel, and complete the virtual assembly from bottom to top. And using the finite element software model analysis function determines the material parameters and quality parameters of model; then establish the three-dimensional entity model of the imported into the ADAMS software, and the appropriate the constraints imposed on the components, finally get the multi-body dynamics analysis model of.2, by using the theory of finite element analysis, the influence of two kinds of different treatment methods on the whole engine flywheel and crankshaft dynamic performance of flexible processing results. The finite element model of engine crankshaft shafting in Ansys workbench software, the finite element model of shafting the quality unit comprises a flywheel and contains a finite element model of flywheel shafting entity finite element model, based on the two kinds of finite element model for dynamic analysis On the comparative analysis of the quality of the flywheel and flywheel unit entity unit on the dynamic performance of the overall effect of.3 on the rigid Adams software will replace the flexible body of engine crankshaft engine crankshaft, obtained a rigid flexible model of engine crankshaft. The rigid flexible hybrid model for the analysis of the kinematics and dynamics simulation on kinematics characteristic curve and obtain the crank pin the piston based dynamic characteristic curves of piston pin parts on the dynamic characteristics of the engine crank and makes a.4 analysis, analysis of forced vibration simulation of crankshaft torsion at different speed conditions by using Ansys Workbench software and Adams software, the response of the free end of crankshaft and flywheel torsion time domain and frequency domain. The vibration response of time-domain and frequency-domain response analysis results show that the crankshaft will produce significantly The first-order torsional resonance, more attention should be paid to.5, in-depth study of the engine crankshaft torsional vibration control methods and measures, the results of vibration simulation analysis and design theory of torsional damper with the engine crankshaft free end, the detailed design of the shock absorber, and through the comparative analysis of the design of shock absorber, after the crankshaft vibration simulation results verified the crankshaft force the effectiveness of torsional damper. At the same time, through the adjustment of shaft torsional vibration energy of the natural frequency and the input of the system to study the effect of torsional vibration.

【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TK403

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