应用奇点法计算流体对结构振动的影响以及关于附连水质量的相似关系

本文把流体力学奇点法与结构有限元法相结合,计算流体对结构振动的影响。这种方法用结构浸水面上的边界元代替流体所占空间内的流体元,可以大大节省计算机容量和减少计算机时。本文还分析了附连水质量计算中的相似关系。文中得出的这些关系使得有可能应用奇点法和有限元法的计算结果为一些较复杂形状的结构得出简便而实用的附连水质量计算公式。文中给出了应用作者所编计算机程序计算附连水质量和水中结构固有振动频率的实际例子——不同浸水情况下的平板、带弹性防挠材的板、实船底部板格以及船舶艉部立体舱段。计算结果与试验结果进行了比较,二者基本符合。

CALCULATION OF THE EFFECT OF WATER ON STRUCTURAL VIBRATION BY SINGULARITY METHOD AND SIMILITUDE PRINCIPLE OF ADDED MASS

The effect of water on structural vibration is calculated by singularity method combined with finite element method which is used to deal with structure. The boundary elements on the interface between the solid and the fluid are used instead of fluid elements distributed in the space, and thus the memory capacity required by the computer program and the computing time are greatly reduced.The similitude principle regarding the added mass is analyzed. The relationship between fluid and structure obtained in this paper enables us deduce a compact formulae for calculation of added mass of structures with complicated contours by using the singularity method combined with finite element method.The added mass and frequencies of various structures, calculated by authors, are listed in this paper. Those structures are plates and stiffened panels, either totally or partially immersed, and a ship stern. The calculated results are compared with those of the experiments. They are in good agreement.