充液圆柱壳内旋转重力波的振动分析  

Vibration Analysis of the Revolving Gravity Waves in Fluid-Filled Cylindrical Shells

作　　者：刘习军[1] 刘国英[1] 贾启芬[1] 张素侠[1] 

机构地区：[1]天津大学机械工程学院,天津300072

出　　处：《天津大学学报（自然科学与工程技术版）》2005年第4期288-293,共6页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(10172064)

摘　　要：为揭示充液弹性圆柱壳受高频激励,壳内自由液面出现低频大幅旋转重力波的产生机理,应用非线性动力学理论,在考虑弹性壳与流体的非线性耦合条件下,建立了壳液耦合系统的非线性振动方程组.运用Runge Kutta法进行数值求解,得到了该系统振动的时间历程及频谱特性曲线,进一步分析了系统的非线性动力学特性.结果发现,当激励力幅值足够大,且激励力频率在壳体固有频率与液体固有频率之和的附近窄频带内时,壳内自由液面会出现大幅低频旋转重力波.由此可知,低频大幅旋转重力波的产生机理是由壳体两个同频率模态同时在壳液耦合系统非线性因素的作用下而引起的组合共振.In order to research into the generant mechanism of the phenomenon that low-frequency and large-amplitude revolving gravity waves may be generated by the external excitation with high frequency in fluid-filled cylindrical shells,a set of nonlinear equations for the multi-degree of freedom system were established by app-(lying) the nonlinear dynamic theory, when the coupling conditions at the fluid-structure interface were consi-(dered).The numerical computation was carried out by means of the Runge-Kutta method.And the time course curves and amplitude-frequency characteristic curves were obtained,which further analyzed the system′s nonli-(near) dynamic characteristics.The analysis shows that the vibration mechanism of the low-frequency and large-amplitude revolving gravity waves is the system′s coupled resonance,which is caused by the two kinds of shell vibration modes with the same frequency coexisting under the influence of the system′s nonlinear factors.Only when the frequency of the excitation is equal to the summation of the shell frequency and the liquid frequency approximately,and the amplitude is big enough, will revolving gravity waves appear on the liquid surface.

关 键 词：液固耦合 旋转重力波 非线性振动 组合共振 

分 类 号：O322[理学—一般力学与力学基础]