横摇作用下气囊-浮筏耦合船用转子系统的非线性动力学特性

Nonlinear dynamic behavior of marine rotor system coupled with air bag-floating raft under ship rolling motion

为了研究横摇作用下气囊-浮筏耦合船用转子系统的非线性动力学特性,针对船舶横摇运动对气囊-浮筏耦合船用转子系统的影响,建立了横摇与非线性油膜力共同作用下系统的动力学模型,并对动力学方程进行无量纲化处理。采用数值方法求解无量纲方程得到系统的动力学稳态响应,重点研究转子转速和横摇幅值变化对系统动力学特性的影响。研究结果表明:横摇作用下的气囊-浮筏耦合船用转子系统,随着转子转速的增加,运动状态由准周期过渡到混沌;与无横摇作用时系统相比,振动幅值明显增大,运动状态更为复杂。一般情况下横摇作用下系统的分岔与混沌特性不受横摇幅值增减的影响,但其振动幅值会随着横摇幅值的增大而以非线性的形式增大。

In order to study the nonlinear dynamic behavior of a marine rotor system coupled with an air bag floating raft under ship rolling motion,a dynamic model of the marine rotor-bearing system coupled with an air bag-floating raft under the combined action of rolling motion was established.By employing the numeri⁃cal method to solve the dimensionless equations,the dynamic steady-state response of the system was simu⁃lated.Special efforts were made to investigate the influence of rotor speed and roll amplitude change on sys⁃tem dynamic behavior.The results indicate that the marine rotor system coupled with the air bag-floating raft under rolling action changes from quasi-periodic to chaos as the rotor speed increases.Compared with the case without rolling action,the vibration amplitude of the system under the rolling action is obviously in⁃creased,and the motion state is more complicated.The bifurcation and chaotic characteristics of the system under the rolling action are not affected by the increase or decrease of the roll amplitude,but its vibration am⁃plitude increases in a non-linear manner with the increase of the roll amplitude.