Simplified Modeling Method Research For Carrier-based Helicopter On-deck Dynamic

With the development of China's marine strategy and the widespread use of carrier-based helicopters,the safety of carrier-based helicopters when taking off and landing in complex conditions becomes critical important.In the process of carrier-based helicopters taking off and landing,ship resonance often causes the tragedy of fatal crash.Therefore,the dynamic instability problem about ship resonance of carrier-based helicopter should be solved urgently.Based on the simplified modeling of carrier-based helicopter on-deck dynamic,the problem of ship resonance is studied in this paper.Firstly,the dynamic model of eight-degrees-of-freedom coupling system for articulated single rotor helicopter is established by using multi blade coordinate transformation method,equivalent linearization method and classical Newton method based on the previous studies.Then,the dynamic stability of the coupled system is numerical analyzed by the combination of the state space eigenvalue method,the fourth-order Runge-Kutta method and phase plot method.In order to avoid ship resonance of carrier-based helicopter,the method for selecting the required blade lead-lag damping and landing gear damping is presented based on the numerical analysis.Afterwards,the dynamics model considering the harpoon deck-lock device of carrier-based helicopter coupling system is established and the influence of harpoon deck-lock device on the stability of carrier-based helicopter coupled system is analyzed.Finally,the dynamic stability of established virtual prototype of carrier-based helicopter coupling system is simulated by LMS Virtual.Lab,which verifies the accuracy of the dynamic model.In this paper,the equivalent linearization method is used to simplify the modeling of landing gear under the on-deck conditions,which avoids the complicity of solving nonlinear dynamic system.By calculating the required damping of critical stable system,an effective reference for the reasonable allocation of blade lead-lag damping and landing gear damping is provided and the influence of harpoon deck-lock device on the carrier-based helicopter on-deck dynamic is analyzed.The research of this paper has important theoretical significance and engineering application value for the safety of carrier-based helicopters taking off and landing.