A Study on the Feasibility of Using Adaptive Structures in the Attenuation of Vibration Characteristics of Rotary Wings.

This paper investigates the feasibility of employing adaptive material to build both sensors and actuators to attenuate the higher harmonic loads developed at the helicopter rotor blades using the elastic flatwise bending (second for hingeless rotors) and the first elastic torsion modes of a single blade deserve special attention in the vibration control. Theoretical investigations, supported by wind tunnel and flight tests, confirmed that these modes are responsible for the larger amplitude loads at 3/rev in four-blade hingeless rotors. This is a situation for which IBC, based on a collocated actuator-sensor arrangement along the blade, and tailored to act specifically on the bending and the torsion modes, is expected to bring further improvements to the reduction of the overall dynamic response of helicopters. The results indicate that there are already real situations for which the adaptive material has enough power to accomplish the task without saturation of the applied electrical field.

[1]  V. R. Murthy.  Dynamic characteristics of rotor blades - Integrating matrix method , 1977 .

[2]  C. E. Hammond,et al.  A Unified Approach to the Optimal Design of Adaptive and Gain Scheduled Controllers to Achieve Minimum Helicopter Rotor Vibration , 1981 .

[3]  N. D. Ham R.M. Mckillip.  Simple System for Helicopter Individual-Blade-Control And Its Application To Gust Alleviation , 1980 .

[4]  Fred Nitzsche.  Aeroelastic analysis of a Darrieus type wind turbine blade with troposkien geometry , 1983 .

[5]  Ronald L. Spangler,et al.  Piezoelectric actuators for helicopter rotor control , 1989 .

[6]  T. A. Weisshaar,et al.  Controlling panel flutter using adaptive materials , 1991 .

[7]  Khanh Nguyen,et al.  APPLICATION OF HIGHER HARMONIC CONTROL (HHC) TO HINGELESS ROTOR SYSTEMS , 1989 .

[8]  Peretz P. Friedmann,et al.  Coupled rotor-flexible fuselage vibration reduction using open loop higher harmonic control , 1991 .

[9]  Francis C. Moon,et al.  Modal Sensors/Actuators , 1990 .

[10]  Richard S. Teal,et al.  Higher Harmonic Control: Wind Tunnel Demonstration of Fully Effective Vibratory Hub Force Suppression , 1985 .

[11]  L. Librescu,et al.  Free vibration and aeroelastic divergence of aircraft wings modelledas composite thin-walled beams , 1991 .

[12]  T. A. Weisshaar,et al.  Static aeroelastic behavior of an adaptive laminated piezoelectric composite wing , 1990 .

[13]  W.-W. Chiang,et al.  Piezoelectric modal sensors and actuators achieving critical active damping on a cantilever plate , 1989 .

[14]  Edward F. Crawley,et al.  Fundamental mechanisms of aeroelastic control with control surface and strain actuation , 1991 .

[15]  W.-W. Chiang,et al.  Piezoelectric strain rate sensor and actuator designs for active vibration control , 1991 .

[16]  Peretz P. Friedmann,et al.  Rotary-wing aeroelasticity with application to VTOL vehicles , 1990 .

[17]  L. Meirovitch,et al.  Modal-Space Control of Distributed Gyroscopic Systems , 1980 .