Recent Advances in Smart-material Rotor Control Actuation

This paper reviews recent achievements in the application of active-materials actuation to counteract aeroelastic and vibration effects in helicopters and fixed wing aircraft. A brief review of the induced-strain actuation principles and capabilities is done first. Attention is 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. Conclusions and directions for further work are presented