考虑浮体弹性变形的锚泊系统分析方法

Analysis method for a mooring system by considering the elastic deformations of a floating body

传统的锚泊系统分析方法一般是假设结构物为刚性不可变形的,这种假设对于常规海洋结构物的锚泊系统分析,其精度是可以接受的,然而对于弹性体(比如超大型浮体)来说,这种浮体刚性的假设显然是不合理的。本文基于摄动理论,分别给出了锚泊浮体(同时包括弹性体和刚性体)和锚泊系统的一阶运动方程。分别用三维水弹性理论和Goodman-Lance法求解浮体的动力响应和锚泊线的运动,并给出了两者之间的协调关系。通过数值算例分析表明,对于超大型浮体,其弹性特性对锚泊系统特性的影响是不可忽略的。

Most of researches on the dynamic behavior of mooring systems often assumed the structure to be a rigid body. A rigid body assumption may be acceptable for traditional floating marine structures, but it is certainly not valid for very large floating structures. The mathematical model based on perturbation method for the dynamic response analysis of a moored flexible floating body is presented. The expressions for coefficients of the generalized first-order hydrodynamic forces in regular waves and the perturbation motion equation of mooring lines are given. The Goodman-Lance method is used to solve the mooring lines' motion equation. Three-dimensional hydroelasticity theory is used to calculate the principal coordinate response of the flexible floating body. The expressions of the coupling relationship between the motion of the floating structure and the mooring lines are also given. The theory is illustrated by numerical examples. And the result shows that the elasticity of the very large floating structure has considerable effect on the dynamic response of the mooring system.