Experimental Modal Analysis of a Gyroscopic Rotor in Active Magnetic Bearings

For a gyroscopic rotor in active magnetic bearings, the rigid body natural frequencies and mode shapes are investigated. An impulsive excitation force is generated by two rectangular pulses in the current control reference signal. With vibration measurements available in two perpendicular directions for each bearing, experimental modal analyses are performed at rotational speeds up to 100000 rpm. Identification results demonstrate the gyroscopic split of natural frequencies.