中文摘要：

应用流体力学和弹性力学知识，建立了弹性圆柱壳液耦合系统的非线性振动方程，利用平均法，得到了4个自由度的非线性振动方程组的一次近似解析解，求出了低频大幅旋转重力波幅值随激振力频率和幅值的变化关系曲线，分析了系统非线性振动过程的动力特性，从理论上进一步解释了壳液耦合系统在受高频激励下产生低频大幅旋转重力波的条件与原因，近似解析解与数值解和实验现象基本吻合。

英文摘要：

In the context of hydromechanics and elasticity, nonlinear vibration equations of cylindrical shell ot coupling system are established. Using the average method, the first approximate analytical solution of nonlinear vibration equations with four degrees of freedom is obtained. For low frequency ＆ large magnitude rotating gravity wave, this paper develops the relationship between its amplitude and vibration properties of exciting forces, thus the dynamic characters of nonlinear vibration system are analyzed. The approximate analytical solution is basically consistent with the numerical solution and experimental phenomena.