Dynamics of unbalanced flexible rotor with anisotropic supports during contact with the stator

One of the important problems of rotor systems mechanics is rotor dynamics when it contacts stator elements. There are well-known cases when rotor - stator rubbing led to serious accidents. The main aim of the work is to gather data about movement of rotor upon contact with the stator suitable for verification of mathematical models. Also diagnostic features of rubbing in the rotor system with anisotropic stiffness were determined. Vibration behavior of the unbalanced flexible rotor with two ball bearings when it contacts the stator was experimentally investigated. The influence of support stiffness anisotropy, unbalance value, contact properties and stator elastic flexibility were taken into consideration. The calculation method of rotor dynamics with the stator rubbing was created and identified via experimental data. This method is based on Jeffcott model and allows taking into consideration the support stiffness anisotropy, unbalance value, contact properties, rpm and stator elastic flexibility. The model explains the mechanism of additional harmonics appearing in Campbell diagram and the presence of frequency response when the rotor contacts the stator. It makes possible to use phenomena of additional harmonics appearing as a diagnostic feature. The created experimental method and gathered data can be used for the verification and tuning of mathematical models. The suggested mathematical method of rotor-stator interaction modelling is suitable for the detection and elimination of rotor stator contacting situations. Also, it can be used as a basis for more complicated rotor system models.