基于单元分析的车辆动力传动系统建模及扭振减振研究

发布时间：2018-05-08 23:37

本文选题：车辆 + 扭振　；参考：《重庆大学》2014年硕士论文

【摘要】：由发动机、离合器、变速器、驱动轮等组成的车辆动力传动系统，是一个既有连续质量，又有集中质量的非线性耦合的复杂系统，当输入激励频率与系统的固有频率接近或相等时，将产生共振，加剧车辆动力传动系统的扭振响应，在发动机输出端与变速器之间配备双质量飞轮扭振减振器将有利于解决车辆动力传动系统的扭振现象。为探究车辆动力传动系统各部分动力学参数对动态输出响应的影响，实现双质量飞轮的合理匹配以达到扭振减振的目的，论文对车辆动力传动系统扭振及双质量飞轮的国内外发展现状及趋势进行了研究，并在与企业合作研发的基础上，对整车系统的发动机、双质量飞轮、变速器及驱动轮等各单元进行了详细的研究与分析，建立了基于单元分析的车辆动力传动系扭振减振模型，并对系统固有特性进行了计算，表明了引入双质量飞轮后能有效地调节系统固有频率范围，详细地分析了系统各单元动力学参数对系统固有特性的灵敏度影响，揭示了系统参数与系统固有特性的内在联系，为系统各单元动力学参数的合理匹配优化和新型双质量飞轮扭振减振器提供了设计依据和理论指导，并在机械系统动力学软件ADAMS中进行了受迫振动仿真分析，验证了引入双质量飞轮能有效地衰减系统输入激励的扭振响应。论文的主要研究工作包括以下几个部分： ①在车辆结构及功能基础上，将整车系统进行拆分为不同的子单元(发动机单元、双质量飞轮扭振减振器单元、变速器单元等)并建立相应的等效单元扭振力学模型，通过一定的准则，，将各单元组合成整车系统扭振减振分析模型，从而获得基于单元分析的车辆动力传动系统模型。对发动机单元，建立单缸活塞-曲柄连杆的动力学模型及其等效力学模型，经相位组合后得到任意多缸发动机的动力输出特性，以作为输入激励进行动力传动系统的动态响应分析。 ②在整车系统扭振模型的基础上，建立相应的自由扭振方程，对系统固有频率进行求解计算，得出系统一阶共振转速低于发动机怠速转速，而二阶共振转速高于发动机最高转速，从而将系统共振转速隔离在发动机工作转速之外，并详细探讨了系统各子单元的等效转动惯量、等效扭转刚度动力学参数变化对系统固有特性的影响，揭示出了系统各动力学参数与系统固有特性的内在联系。 ③在ADAMS中建立车辆系统的扭振减振模型虚拟样机，引入阻尼参数，加载简谐分析后的激励转矩表达式并进行受迫振动仿真分析，表明了系统输入激励的角速度扭振响应经过双质量飞轮后有较好的衰减。
[Abstract]:The vehicle power transmission system, which consists of engine, clutch, transmission and drive wheel, is a complex nonlinear coupling system with both continuous mass and concentrated mass. When the input excitation frequency is close to or equal to the natural frequency of the system, resonance will occur, which will aggravate the torsional vibration response of the vehicle power transmission system. A double mass flywheel torsional vibration absorber between the engine output end and the transmission will be helpful to solve the torsional vibration phenomenon of the vehicle power transmission system. In order to investigate the effect of dynamic parameters of vehicle power transmission system on dynamic output response, and to realize the reasonable matching of double mass flywheels to achieve the purpose of torsional vibration damping, This paper studies the development status and trend of torsional vibration and double mass flywheel in vehicle power transmission system at home and abroad, and on the basis of research and development with enterprises, the engine and double mass flywheel of the whole vehicle system are studied. The transmission and drive wheel are studied and analyzed in detail. The torsional vibration damping model of vehicle power transmission system based on element analysis is established, and the inherent characteristics of the system are calculated. It is shown that the natural frequency range of the system can be adjusted effectively by introducing the double mass flywheel. The influence of the dynamic parameters of the system on the inherent characteristics of the system is analyzed in detail, and the inherent relationship between the system parameters and the inherent characteristics of the system is revealed. It provides the design basis and theoretical guidance for the reasonable matching and optimization of the dynamic parameters of each unit of the system and a new type of twisting vibration absorber with double mass flywheels. The forced vibration simulation analysis is carried out in the mechanical system dynamics software ADAMS. It is verified that the double mass flywheel can effectively attenuate the torsional vibration response of the input excitation of the system. The main research work includes the following parts: On the basis of the structure and function of the vehicle, the whole vehicle system is divided into different sub-units (engine unit, twin-mass flywheel torsional vibration absorber unit, transmission unit, etc.) and the corresponding equivalent unit torsional vibration mechanics model is established. According to certain criteria, each unit is combined into an analysis model of torsional vibration and vibration of the whole vehicle system, and the model of vehicle power transmission system based on element analysis is obtained. For the engine unit, the dynamic model and equivalent mechanical model of a single cylinder piston and crank connecting rod are established. After phase combination, the dynamic output characteristics of any multi-cylinder engine are obtained. The dynamic response of power transmission system is analyzed as input excitation. 2 based on the torsional vibration model of the whole vehicle system, the corresponding free torsional vibration equation is established, and the natural frequency of the system is solved and calculated. It is concluded that the first order resonance speed of the system is lower than the idle speed of the engine. The second order resonance speed is higher than the maximum engine speed, so the system resonance speed is isolated from the engine working speed, and the equivalent moment of inertia of each sub-unit of the system is discussed in detail. The influence of the dynamic parameters of equivalent torsional stiffness on the natural characteristics of the system is discussed, and the relationship between the dynamic parameters of the system and the inherent characteristics of the system is revealed. (3) the virtual prototype of torsional vibration damping model of vehicle system is established in ADAMS, the damping parameter is introduced, the expression of excitation torque after simple harmonic analysis is loaded, and the forced vibration simulation analysis is carried out. It is shown that the torsional vibration response of the system excited by the input angular velocity has a good attenuation after passing through the double mass flywheel.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U463.2;TB535

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