纵摇运动下船用转子-轴承-浮筏气囊耦合系统非线性动力学特性OA北大核心CSTPCD

The nonlinear dynamic characteristics of the rotor-bearing-floating raft airbag system of a ship under pitching motion are studied.Firstly,considering unbalance force,bearing oil film force,floating raft airbag elastic recovery force and inertial force of ship pitching motion,the dynamic model of this system is established according to Lagrange equation.Then,based on the numerical method,the nonlinear dynamic characteristics of this system are analyzed by means of waterfall diagram,axis trajectory diagram,phase diagram,time domain and frequency spectrum diagram.The results show that with the increase of the rotor speed,the motion state of the system under pitching motion excitation changes gradually from quasi-periodic motion to chaotic motion.The amplitude of the vibration response of the rotor is obviously larger than that of the rotor without considering the pitching motion,and there exists a combination of pitch frequency and power frequency in the response.Finally,the influence of pitching amplitude on the characteristics of the rotor bearing-floating raft airbag coupling system dynamics is discussed.