双跨松动转子-轴承系统周期运动稳定性

建立了带有支承松动故障的具有三轴承支承双跨弹性转子-轴承系统非线性动力学模型,利用求解非线性非自治系统周期解的延拓打靶法和Floquet理论,研究了系统周期运动的稳定性及失稳规律。双跨松动转子-轴承系统响应存在着周期运动、拟周期运动和混沌运动等复杂的运动现象,系统以鞍结分岔形式失稳。在不同的转速下,系统会出现鞍结分岔和Hopf分岔等不同的分岔形式;在高转速区,松动端轴颈的运动轨迹呈现出特有的形状。研究结果为有效识别转子-轴承系统的基础松动故障提供了一定的参考。

Stability of Two-span Rotor-Bearing System with Pedestal Looseness Fault

A non-linear dynamic model was established for a two-span elastic rotor-bearing system with pedestal looseness fault supported on three plain journal bearings. Using the continuation-shooting algorithm for periodic solution of nonlinear non-autonomous system, the stability of the system periodic motion was studied taking advantage of the Floquet theory. The periodical, quasi-periodical and chaos motions were found in the system responses. The unstable motion of the rotor system with pedestal looseness fault is in the form of saddle-node bifurcation. There may also appear unstable forms of Hopf bifurcation under different rotating speeds. Peculiar trajectories of loosened journal center is found in high rotating speed region. The conclusions provide theoretic basis giving reference to the failure diagnosis of the rotor-bearing system.