基于滞回碰摩力模型的转子系统碰摩响应研究

转/静子碰摩是影响旋转机械的稳定性与安全性的重要因素之一,而碰摩力的表征则是预测转子系统动力学响应的关键问题。讨论了已有转/静子碰摩力模型的适用范围,重点阐述滞回碰摩力模型的物理意义,并与几种经典的碰摩力模型进行比较;以Jeffcott转子作为典型例子,基于滞回碰摩力模型给出系统的碰摩响应,并与采用线性碰摩力模型所得到的碰摩响应进行比较;利用数值仿真的结果分析静子刚度、转子偏心距等因素对采用滞回碰摩力模型的转子碰摩响应的影响。数值仿真的结果表明:采用滞回碰摩力模型得出的失稳速度(1226 rad/s)低于采用线性碰摩力模型得出的失稳速度(1476 rad/s),且系统的动力学特性更为复杂,因此,可以更真实地反应碰摩的物理实质。

Study on Rub-impact Responses of Rotor Systems Based on Hysteretic Rub-impact Force Model

The rub-impact of rotor/stator is one of the major factors for the stability and safety of rotating machine, while the characterization of the rub-impact force is a key problem in the prediction of dynamical responses of the rotor system. The applicable scope of the existing rotor/stator rub-impact force models was discussed, the physical significances of the hysteretic rub-impact force model was described clearly, and the comparison between the hysteretic rub-impact force model and classical ones was conducted. Taking the Jeffcott rotor as a typical example, the rub-impact responses of system based on the hysteretic rub-impact force model are given and used to compare with the result form the system with linear rub-impact force model. The effects of stator stiffness and the rotor eccentricity on rub-impact responses of the rotor system with the hysteretic rub-impact force model were given to analyze by the numerical results. The numerical simulation results show that the stability threshold speed (1226 rad/s) of the system in terms of the hysteretic rub-impact force model is less than that (1476 rad/s) of the system with linear rub-impact force model, and the dynamic characteristics are more complicated, therefore, the essential physical property of rub-impact can be reflected more veritably.