This paper describes the concept, design, fabrication and testing of a shape memory alloy (SMA) wire actuated tab for in-flight tracking of helicopter rotors. To achieve fine adjustment of tab angle, it is equipped with a locking mechanism and a position feedback controller. The primary components of the actuator are the SMA wires, a fiberglass clamp and a fiberglass hinge tube. The clamp and the hinge tube allow for two separate sets of SMA wires to be utilized. One set of the wires is heat activated while the other remains at ambient conditions. The actuator was mounted in an NACA 0012 blade section chord. Bench-top and open-jet wind tunnel tests conducted on a wing section with 2-wire and 4-wire actuators mounted inside the profile and at a maximum angle of attack of 15 deg and velocity of 120 ft/sec (Mach .11) are described. It is shown that a 2-wire actuator, with an initial plastic deformation of 4.2 % is sufficient to deflect the tab down by 31 deg at a wind speed of 120 ft/sec. In bench-top tests, a position feedback controller demonstrated the ability to track a desired tab position in about 10 seconds. The locking mechanism showed the ability to lock the tab in a desired position during power-off condition.


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    Title :

    Methodology for in-flight tracking of helicopter rotor blades using shape memory alloy actuators


    Additional title:

    Vorgehensweise zur Beobachtung einzelner Hubschrauberrotorblätter im Flug mittels Formgedächtnisaktoren


    Contributors:

    Published in:

    Publication date :

    2004


    Size :

    9 Seiten, 22 Bilder, 2 Tabellen, 19 Quellen




    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English




    Methodology for In-Flight Tracking of Helicopter Rotor Blades Using Shape Memory Alloy Actuators

    Epps, J. J. / Chopra, I. / American Helicopter Society | British Library Conference Proceedings | 2000



    In-Flight Tracking of Helicopter Rotor Blades Using Shape Memory Alloy Actuators

    Epps, J. / Chopra, I. | British Library Conference Proceedings | 1999



    Shape memory alloy actuators for in-flight tracking of helicopter rotor blades [3329-35]

    Epps, J. J. / Chopra, I. / SPIE et al. | British Library Conference Proceedings | 1998