机车车辆颤振现象出现于机车低速制动工况下,与制动过程的非线性制动力,机车车辆的动态结构特性及其相互作用有关。分析颤振现象的机理,基于振型耦合理论建立机车制动颤振现象的动力学模型,利用MATLAB/Simulink软件进行机车车辆颤振过程的动态特性仿真。理论分析和仿真结果表明:当系统阻尼高于一定数值时振动会消失;理论上通过改变材料增大阻尼,可以降低或消除系统的振动,但是改变制动系统材料要考虑到很多影响因素,实际工况不可行;因此,改变系统刚度k1,k2的差值和主振系统的刚度方向(α角),才是减小或消除机车车辆颤振现象的比较经济和直接的方法。
The locomotive and vehicles chatter under low-speed braking has close relationship with non-linear braking force and dynamic characteristics of locomotive structure as well as their interaction. The cause and mechanism of chatter is studied in this paper. The dynamic model of chatter is established based on the theory of oscillation mode coupling. The dynamic characteristics of locomotive and vehicle chatter are simulated with MATLAB/Simulink. Theoretical analysis and simulation results show that the chatter can be reduced or eliminated when the damp of the system increases to a certain numerical value. Theoretically speaking, the chatter can be reduced or eliminated by changing material to increase the damp. However, plenty influencing factors must be considered when adjusting damp by changing material of braking system. It's not feasible in practical condition. Therefore, adjusting the difference of rigidity ( k1, k2) and the direction of main vibration system (α) is the most immediate and cost-effective way to reduce or eliminate locomotive and vehicle chatter.