Analytical Method of Ship Resonance for Helicopters with Wheel Landing Gears

An analytical method of ship resonance dynamic stability countering the helicopter with wheel landing gears is provided.Firstly,according to the characteristics of landing gears acted unsymmetrically with helicopter reeling on ship,the helicopter trim is calculated approximately using the method that landing gears is deformed symmetrically by symmetrical forces and unsymetrically by unsymmetrical forces.Secondly,the stiffness and damp of landing gears are gotten by complex stiffness with the geometry relationship of wheel landing gears.Finally,the analysis of ship resonance dynamic stability of helicopter with wheel landing gears is preformed by using blade vibration modal method to different rotor lift forces and harpoon deck-lock or no deck-lock.The analytical method is verified by examples.