中文摘要：

早期裂纹转子系统中，裂纹故障不易检测到，并可能会进一步引发碰摩故障。文中针对这种耦合故障情形，分析系统的动力特性以及裂纹参数、碰摩参数和轴承参数变化对系统特性的影响。结果表明，裂纹转子系统发生碰摩故障时，两种非线性因素相互影响且不是线性叠加，使系统变得更加复杂。同时三个参数对系统特性有明显不同的影响，尤其是裂纹参数和碰摩参数的变化，系统特性发生较大的变化。因此，工程实际裂纹转子系统的故障监测与诊断过程中，应该充分考虑裂纹故障和碰摩故障之间的相互影响，建立合理的分析模型的基础上，注重监测裂纹参数和碰摩参数变化带来的影响。

英文摘要：

The dynamic characteristics and its early detection are the most important tasks in cracked rotor system. It is diitlcult to accurately estimate the crack. And the vibration will be severe when the rapid rise. So there maybe happen the rubbing faults between the shaft and the bearings. An analytic model has been set up to investigate the crack and rubbing coupling faults. The nonlinear dynamic characteristics of the system can be simulated. Especially, the effect of the variable parameters, such as the crack parameter, the nib parameter and the bearing parameter, are analyzed respectively. The results show that the effects of crack and n~-impact are not their linear summation but their coupling. The rotor system also becomes more complex and the effects of the three nonlinear factors are different. And the effects of crack and ntis-impact parameters are more serious. To detect and diagnose a practical cracked rotor system, the probability of ntis-impact must be taken into account. A reasonable nonlinear dynamic model should be set up, which must consider the coupling of the crack and the ntis-impact. And more attention should pay to the effect of the crack parameter and the rubbing parameter, not to the baring parameter in the rotor system.