Design of an improved shape memory alloy actuator for rotor blade packing

A shape memory alloy actuated tab deflection mechanism for in-flight rotor blade tracking was designed, fabricated and tested. The design, comprises of dual SMA wire actuation device, passive lock and on-blade sensors. The system is integrated with a feedback position controller. Improvements, over the previous design, in shape memory alloy wire clamping mechanism, locking mechanism and controller operation were examined. An analytical model, incorporating Brinson's thermomechanical model was developed to predict actuator behavior. A design methodology, based on this model, was applied to identify the relationship between actuator design parameters and actuator target goals. The actuation system integrated into an NACA0012 blade section was tested on the bench-top. Tracking capability of +/-6degrees with a resolution of +/-0.1degrees was demonstrated. Symmetric and consistent tab deflection capability was demonstrated under closed loop control.