Aeroelastic Investigation of Hingeless Helicopter Blades with Integrated Morphing Actuator

This paper deals with the aeroelastic analysis of a hingeless helicopter blade smarted with a morphing system aimed to the reduction of BVI noise through transformation of the blade tip shape into an anhedral tip type. The proposed actuation system is based on a variable-stiffness device coupled with the actions provided by inertial moments and shape memory alloys (SMA) tie-rods. Since the inertial moments are provided by a suitable mass distribution and the smart system effectiveness is strongly dependent on the amount of it, this work focuses the attention on the resulting modified dynamic and aeroelastic blade responses. In particular, the numerical investigation examines the aeroelastic stability and the rotating frequencies of vibration of the smarted blade, comparing them with those of the baseline configuration. Potentiality and shortcomings of the smarted blade are analysed and possible alternative solutions, as well as, envisaged further improvements are discussed.