A STUDY ON MECHANICAL MODEL OF THE HELICOPTER "GROUND RESONANCE

The key problem to the calculation and optimization design of the helicopter "Ground Resonance" is to correctly build up a mechanical model. In the past, the literature was only concerned with the lag modes of the rotor blade and the flap modes were neglected. But such approaches should be reconsidered now. In order to study the influences of rotating multiblades rotor on the degrees of freedom and also the flap ’’Ground Resonance" of a helicopter, it is necessary to consider not only the lag degrees of freedom but also the flap degrees of freedom. Using Lagrangian equation a dynamical equation of the space model for helicopter "Ground Resonance"is deduced for the first time. Some computation results show that the mechanical model including both lag DOF and flap DOF is more reasonable.