Hydroelastic Behaviors of Artificial Islands in Waves

漂浮机场是目前唯一的漂浮人工岛的原型。在日本流行的浮动机场的设计是非常薄的配置，我们称之为垫式。在我们的研究中，我们发展了一种理论方法来准确地预测海上垫式浮动机场的水弹性行为。1.我们将物体建模为具有小但有限弯曲刚度的薄膜片。这种模型是合理的，因为垫式浮动机场的深度相对于水平维度非常小；长度将是几公里，但深度将是几米。自然，弯曲刚度很小，物体将被视为膜而不是刚性结构，由此推导出水面和膜的高程的边值问题。我们在斜入射角和深水或浅水深度的波浪中处理了拉长形式的膜(数学上无限长)。将膜视为准水面，推导并求解了该边值问题。这个概念对于理解水波中薄膜振动的物理特性是有用的。当水深较浅，应用线性浅水理论时，数值计算变得非常简单，其有效性也是非常可靠的。2.漂浮机场的平面布局在现实中并不是那么简单的长方形。更多的数值方法对于预测其行为和设计真实的机场是不可避免的。提出了一种分析复杂结构波-弹-体相互作用的边界积分方程法。提出了一种求解巨型结构面上极大数量面元方程的有效方法。在我们的半解析解上，用文献[1]中发展的方法对该方案进行了验证。

Floating aiport is currently a unique prototype of the floating artficial island. Popular design in Japan of floating airports is very thin configuration we call a mat-type. In our research we developed a theoretiocal method to predict accurately the hydroelastic behaviors of mat-type floating airports at sea.1.We modelled the body as a sheet of membrane with small but finite magnitude of bending rigidity. This modelling is legitimate because the depth of the mat-type floating airports is very small relatively to the horizontal dimensions ; length will be several kilometers but depth will be several meters. Naturally the bending rigidity is very small and the body will be considered as a membrane rather than a rigid structure.A boundar value problem on the elevation of the water surface and the membrane was derived by implementing this assumption. We treated with the elongated form (mathematically infinitely long) of the mambrane in waves at oblique incidence angle and in deep or shallow water depth. The boundary value problem was derived and solved with considering the membrane as a quasi water surface. This idea is useful in understanding physics of the vibration of the membrane in water waves. Numerical computation becomes extremely simple and its validity is so reliable when the water depth is shallow and linear shllow water theory is applied.2.Planar configuration of the floating airports is not so simply long rectangular in reality. More numerically involved method is inevitable for predicting its behabiors and designing a real airport. A boundary integral equation method was developed for mathematically analyzing waves-elastic-body interaction of complicated configuration. A efficient scheme was devised for solving equations of extremely large number of panels on huge structure surface. This scheme was validated on our semi-analytical solution by the method developed in 1 for simpler geometry.