深海系缆动张力的超谐动力响应  

Analysis of dynamic tension nonlinear characteristics for mooring system in the deep water

作　　者：张若瑜[1] 唐友刚[1] 宋吉哲[2] 刘利琴[1] 

机构地区：[1]天津大学建筑工程学院暨港口与海洋工程教育部重点实验室,天津300072 [2]中国船级社天津分社,天津300457

出　　处：《船舶力学》2012年第7期804-811,共8页Journal of Ship Mechanics

基　　金："863"高技术研究发展计划资助项目(2007AA09Z304);国家自然科学基金资助项目(50879057);国家自然科学基金重点资助项目(50639030)

摘　　要：文章考虑深水系缆的拉伸和弯曲变形,取正交坐标和切向量描述任意结点的6个广义位移,考虑缆变形的几何非线性和水动力影响,基于细长杆理论推导缆索的单元刚度矩阵,引入单元内张力一致假设,推导出12×12的非线性刚度矩阵,并与有限元软件对接。针对1800m水深平台的系缆,考虑系缆端点垂荡运动,以及端点垂荡、横荡和海流作用两种状态下系泊系统的动力响应。计算结果表明,端点运动和海流作用,引起系缆系统的二倍超谐动力响应,并且随着流速增大,系缆超谐动力响应增大,系缆的超谐动张力分量对于缆索疲劳累积损伤具有重要影响,在系缆疲劳分析时应该予以考虑。Abstract：By considering the extension and bending deformation of cable in the deep sea, the 6 generalized displacements of the nodes are described by rectangular coordinate and their tangent vector. The hypothesis that tension in the element will not be changed is adopted. The 12×12 nonlinear stiffness matrix is obtained based on the rod theory considering the geometric nonlinearity and the effect of water dynamic and the el- ement can be called by general finite element software. The dynamic responses of mooring system under heave motion at the end of cable are calculated and the dynamic response under heave, sway and fluid-drag force is calculated, too. The results show that 2-times super-harmonic response of mooring system is caused by the motion of upper point and the effect of fluid, and with the increase of fluid velocity, the super-har- monic response of the system increases. The super-harmonic response component has significant influence on fatigue cumulative damage of cable, and should be considered in the fatigue analysis.

关 键 词：细长杆理论 有限元法 系泊系统 动张力 

分 类 号：U674.381[交通运输工程—船舶及航道工程]