Smart materials induced strain actuation for aeroelastic and vibrations control

A review of recent achievements in the application of active-materials actuation to counteract aeroelastic and vibration effects in helicopters and fixed wing aircraft will be presented. The principles of induced-strain actuation and the capability of various smart materials to realize displacement, force, energy and power will be briefly summarized. Attention is first focused on the smart rotor-blade applications. The induced twist, active blade tip, and active blade flap concepts are presented and discussed. A number of ingenious displacement amplifications methods, both solid-state and levered, are described. Emphasis is placed on experimental results that prove the expectations and reveal the possible limitations of each particular concept. Full-scale smart rotor efforts are also highlighted. Next, fixed wing aircraft applications are considered. Experiments of active flutter control, buffet suppression, gust load alleviation, and sonic fatigue reduction are discussed. Conclusions and directions for further work are presented.