Numerical simulation of tethered buoy dynamics using mixed finite elements
Numerical simulation of tethered buoy dynamics using mixed finite elements
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DOI：
10.1016/j.cma.2007.04.012
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发表时间：
2007-09
影响因子：
7.2
通讯作者：
A. Montano;M. Restelli;R. Sacco
中科院分区：
文献类型：
--
作者：
A. Montano;M. Restelli;R. Sacco
在这篇文章中，我们设计了一个模拟工具的动力学系留浮标，这是一个系泊系统，由一个刚性的浮体（浮标）连接的弹性电缆（系泊线）的流体环境的底部。整体解决方案算法的准确性和鲁棒性基于三个主要成分的适当选择。第一个成分是使用一种新的混合有限元公式的系泊线，它允许一个强大的建模的电缆，即使在一个无限值的杨氏模量的限制。第二个要素是在浮体的运动方程中使用四元数，而不是欧拉角，这避免了在大旋转存在下的角度奇异性。第三个成分是使用隐式方法（向后欧拉）的时间离散化，结合阻尼牛顿法的解决方案所产生的非线性系统，这避免了计算效率低下的显式时间积分方案中存在的准不可扩展的电缆和精细的空间网格尺寸。系泊系统模型的物理健全性和建议的数值方法的准确性和鲁棒性进行了验证，在静态和动态工业工作条件下的系留浮标的研究。
In this article, we devise a simulation tool of the dynamics of a tethered buoy, which is a mooring system consisting of a rigid floating body (buoy) connected by an elastic cable (mooring line) to the bottom of the fluid environment. The accuracy and robustness of the overall solution algorithm are based on an appropriate choice of three main ingredients. The first ingredient is the use of a novel mixed finite element formulation for the mooring line, which allows a robust modeling of the cable even in the limit of an infinite value of the Young modulus. The second ingredient is the use of quaternions in the equations of motion of the floating body, instead of Euler angles, which avoids angle singularities in the presence of large rotations. The third ingredient is the use of an implicit method (Backward Euler) for time discretization, in conjunction with a damped Newton method for the solution of the resulting nonlinear system, which avoids computational inefficiency of explicit time integration schemes in the presence of quasi-inextensible cables and a fine spatial grid size. The physical soundness of the mooring system model and the accuracy and robustness of the proposed numerical procedure are validated in the study of a tethered buoy operating under static and dynamic industrial-like working conditions.