Introductory PZT actuators optimal working configuration experimental study in a turbofan engine fan rotor blade

Vibration suppression systems are often crucial to extend the life cycle of the structures in several engineering fields. The passive systems are the most commonly used but, in case of dynamic loads, the active systems show a greater efficiency. Since the external forces acting on a rotating blade may excite several vibrational modes simultaneously, an active multi-modal damping device could enhance the damping action. The piezoelectric (PZT) actuators seem to be the most promising but their placing on the structure plays a crucial role. In this paper, some PZT actuators have been mounted on the surface of an actual rotor blade from the second fan stage of a turbofan engine and their working configuration has been optimized on the basis of a previously developed model. Thereby, the actuators are able to efficiently damp the most detrimental resonant mode or a resonant modes coupling. The experimental results show that the proposed system well suits the application and may be considered as an alternative method to deal with vibration issues in turbomachinery blades.