Abstract: Aiming to the blade tip rubbing-induced vibration of a rotor system, based on the rotor-blade-stator coupling system model, the numerical calculation of steady and transient responses of the rotor and stator was done by using harmonic balance method and Newmark-β method, and the effect of various parameters on vibration responses was also analyzed. The result shows that:the "hard" nonlinear characteristic is presented in the steady responses of rotor and stator under blade-tip rubbing; the increment of offset can bring the peak-shift forward and the nonlinear characteristic is more obvious; the contact stiffness can aggravate the vibration and discreteness; "peak clipping" can be more obvious as the number of blade increasing. Due to the restraint of stator, the peak of transient response is restricted obviously. Meanwhile, the unsteady motion that makes the vibration of the system increasing instantaneously can be found. In addition to simulation analysis, the rubbing vibration displacements of the rotor and stator were measured based on a rotor-blade rubbing rig. The test result shows that:the vibration characteristics of blade is reflected in the shaft responses, and the frequency modulation caused by rotor whirling can be presented in vibration responses of the stator.

Key words: blade tip rubbing, numerical analysis, experimental investigation, rotor system, steady and transient response