Individual Blade Control for Helicopter Rotor Blade One/Rev Vibration Reduction. Phase 1

Results of a Phase- SBIR study directed at the use of Individual Blade Control (IBC) for 1/rev helicopter rotor vibration reduction are described. Past approaches, analytical studies, and current technology for 1/rev vibration reduction are surveyed, and then a notional scheme for implementing an IBC-based control device using shape memory alloys (SMA) is introduced. In order to quantify the required performance from this scheme, investigations into the sources of 1/rev vibration, and possible methods for its control are simulated using an aeroelastic analysis. Actuation concepts using SMA wires are analyzed, with engineering support from limited benchtop conceptual test models. Finally, implementation issues are discussed, and a plan for continued work leading to prototype development for this system is outlined. The results from this Phase 1 study indicate that the proposed innovative scheme for providing active 1/rev vibration control for helicopter rotors should lead to a practical system, that would be developed and prototyped under a follow-on Phase 2 program. (AN)