Semi-Active Damping of Ground Resonance in Helicopters Using Magnetorheological Dampers

摘要

The capabilities of physically motivated magnetorheological (MR) dampers to mitigate ground resonance instability and control the damping level of rotor lag modes will be assessed. The objectives of this research are threefold: (1) develop a methodology for the integration of the MR damper into a classic linear ground resonance analysis assuming an isotropic rotor hub (all dampers and blades similar) or an anisotropic rotor hub (for example, lag damper dissimilarity due to damage), (2) assess whether MR dampers can stabilize a rotor system that exhibits unstable ground resonance, and (3) assess whether MR dampers can stabilize a rotor which exhibits unstable ground resonance behavior as a result of lag damper degradation or damage. The analysis developed in this study demonstrates that MR dampers, in conjunction with semi-active feedback control using sliding mode or feedback linearization strategies, can achieve these goals.