中文摘要：

建立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，对其复杂的运动特性进行数值研究，分析松动质量对系统非线性特性的影响和故障特征。研究结果表明，在高转速区，支承松动质量对系统运动特性有显著影响，特别是混沌和周期3分频运动；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—轴承系统的支承松动故障提供一定参考。

英文摘要：

A non-linear dynamic model was established of a two-span elastic rotor-bearlng system with pedestal looseness fault supported on three plain journal bearings. The complex motion characteristics of the rotor-bearing system were numerically studied, and the influences of the looseness mass to the nonlinear characteristics were analyzed. The results indicate there are marked influences of the looseness mass to the characteristics of the system in high rotate speed region, especially the chaos and period-3 motions. Peculiar trajectories of loosened journal center slightly shaking pedestal is found. A theoretic reference is provided to diagnose the fault of pedestal looseness in the rotor-bearing system effectively.