波传播法求解低频激励下水中加端板圆柱壳的振动  

Analysis of the low frequency vibration of a submerged cylindrical shell with endplates based on wave propagation approach

作　　者：陈美霞[1] 张聪[1] 邓乃旗 魏建辉[1] 谢坤[1] 

机构地区：[1]华中科技大学船舶与海洋工程学院,湖北武汉430074

出　　处：《振动工程学报》2014年第6期842-851,共10页Journal of Vibration Engineering

基　　金：国家自然科学基金资助项目(51179071);中央高校基本科研业务费资助项目HUST(2012QN056)

摘　　要：采用波传播法研究了低频下水中壳体的振动与响应。水中壳体由有限长加流体载荷的圆柱壳和两端的圆形端板组成,其中外部流体载荷用无限长模型进行近似处理。为了模拟推动系统的激励及船体上某一点激励,分别考虑了不同位置的轴向载荷和径向载荷,讨论了单个周向模态下的位移在总位移中的比重。主要研究了4种载荷,即作用在端板中心的轴对称载荷、作用在端板与圆柱连接处的轴向载荷、作用在连接处的径向载荷和作用在壳体中间的径向载荷,比较得出了轴对称和非轴对称、同一点不同方向载荷、同一方向不同位置载荷的响应位移的不同。此外,还研究了两端端板对不同载荷下水中壳体响应的影响,得出了端板主要抑制了壳体的较高阶模态下径向位移的结论。解析法结果与有限元法结果进行了比较,验证了该方法的正确性。The low frequency dynamic responses of a submerged hull are presented.The solutions are in the form of a wave travelling in the axial direction.The submerged hull is modelled as a finite fluid-loaded cylindrical shell closed at each end by circular plates.The external pressure acting on the hull due to the fluid loading is analytically calculated using an infinite model.Axial and radial excitations set at the different places of the hull are considered to simulate excitation from the propulsion system and the excitation at one point in the middle of the shell.Four cases of excitations are discussed in details,which corresponds respectively to the cases that the axial excitations are located at both the centre of the endplate and the edge of the endplate,and the radial excitations are located at both the edge of the endplate and the middle of the cylindrical shell.The contributions from the individual circumferential modes on the hull structural responses are studied.Results are presented by comparing the frequency dynamic responses of shell under axi-symmetric excitations with asymmetric excitations,two excitations in different directions but at the same point,two excitations at different points but in the same direction.The effects of endplates in different cases are also discussed.It was shown that the endplates mainly decrease the radial displacement at higher circumferential modes.Results from the analytical models are validated by numerical results from Ansys model,of which both the hull and the fluid are built by finite elements.

关 键 词：船舶振动 水下圆柱壳 波传播法 轴对称载荷 非轴对称载荷 

分 类 号：U661.44[交通运输工程—船舶及航道工程]