VIBRATION FAILURE ANALYSIS OF MULTI-DISK HIGH-SPEED ROTOR BASED ON ROTARY INERTIA LOAD MODEL

The fan rotor of an advanced low-bypass turbofan engine is usually composed of multistage blisk, a typical multi-disk high-speed rotor working in the postcritical range. A fan rotor test rig had been well balanced, but the phenomenon of excessive vibration occurred several times. This phenomenon showed that the traditional balance theory based on mass eccentricity control has limitations for multi-disk high-speed rotors. Therefore, an analysis model was established in this paper that described the rotor's mass distribution and the rotary inertia load by two kinds of parameters: the eccentricity and the skew angle of the principal axis of inertia. Then the dynamic response properties of the rotor were simulated and analyzed. The model and simulation results showed that if the principal axis of inertia of the rotor skewed, the amplitude of bearing dynamic load continues to increase with speed, which agrees with the experimental data. Therefore, for the multi-disk rotor, it is necessary to control its eccentricity and the skew angle of the principal axis of inertia at the same time to effectively reduce its dynamic response at high speed.