In this study, shape memory alloy damper with characteristics of pseudoelastic hysteresis for helicopter rotor blades are investigated. SMAs can be available in damping augmentation of vibrating structures. SMAs show large hysteresis in the process of pseudoelastic austenite-martensite phase transformation which takes place while subjected to loading above the austenite finish temperature. Since SMAs display pseudoelastic hysteresis behaviour over large strain ranges, a significant amount of energy dissipation is possible. A damper can be designed with SMA wires prestressed to a baseline level somewhere in the middle of the pseudoelastic stress range. An experimental study of the effects of pre-strain and cyclic strain amplitude as well as frequency on the damping behaviour of pseudoelastic shape memory alloy wires are performed. The effects of the shape memory alloy damper on aeroelastic and ground resonance stability of helicopter are studied. In aeroelastic stability, the dynamic characteristics of blades related to pitch angle and the amplitude of lag motion for the rotor equipped with SMA damper were examined. The performance of SMA damper on ground resonance instability are presented through the frequencies and modal damping with respect to rotating speed.
Stability augmentation of helicopter rotor blades using passive damping of shape memory alloys
Stabilitätsverstärkung eines Hubschrauber-Rotorblatts durch die passive Dämpfung von Formgedächtnislegierungen
2004
13 Seiten, 12 Bilder, 2 Tabellen, 14 Quellen
Conference paper
English
Engineering Index Backfile | 1955
In-Flight Tracking of Helicopter Rotor Blades Using Shape Memory Alloy Actuators
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Online Contents | 2004
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