具有初始弯曲和刚度不对称的转子碰磨现象分析

Rub-Impact Phenomenon of Rotor System with Initial Bending and Asymmetric Stiffness

建立了考虑转子转速的新的碰磨力模型 ,分析了具有初始弯曲和刚度不对称转子系统的碰磨响应 ,得到了系统参数对系统分叉和混沌响应的影响 .通过与刚度对称转子系统的碰磨现象进行比较发现 :具有初弯和刚度不对称转子系统的碰磨响应有很多不同的运动特性 ,这种不同来源于转子两个方向刚度的耦合作用 ,刚度不对称越大 ,系统越容易发生拟周期响应、越容易导致碰磨出现 ;不平衡参数越大 ,系统响应的振幅越大、越容易发生碰磨和周期解分叉 ;阻尼系数越小 ,发生周期解分叉的转速比越小 .

A new model of rub impact force considering varied rotating speed was derived and the rub impact response of a rotor system with initial bending and asymmetric stiffness was analyzed. The influence of system parameters on the bifurcation and chaos response of the system was calculated and investigated. Many different response characters between the rotor systems with and without initial bending and asymmetrical stiffness are observed and the research indicates that the difference comes from the coupling of stiffness in two directions. The larger the stiffness asymmetry is, the easier it is for quasi periodic response to occur and the easier it is for rub impact response to occur. The larger the unbalance parameter is, the larger the vibration amplitude is and the easier it is for rub impact response and periodic bifurcation response to occur. Smaller damping coefficient will make the rotating speed for periodic bifurcation smaller. Different nonlinear phenomena can be observed in system's response with the changing of rotating speed ratio.