Development of an SMA actuator for in-flight rotor blade tracking

摘要: Another solution to the helicopter blade-tracking problem has been investigated. A discrete, blade-installed actuator utilizing shape memory alloy (SMA) torsion tubes developed enable in-flight rotor tracking. SMA from three materials were tested and one was selected for its cyclic stability. Improved tube fabrication, heating, end attachment methods, locking schemes developed. The final prototype employed two bi-axial actuation/bias; a activated lock power off operation, integrated microprocessor control electronics. Tests under static dynamic loading showed that actuation requirements, except bandwidth, met. Increased bandwidth may be obtained by improved algorithms or cooling. enables an in-flight, real-time adjustment of tab. Projected payoffs are reduced maintenance cost as well vibrations performance.