Coupled-dynamic analysis of floating structures with polyester mooring lines
Coupled-dynamic analysis of floating structures with polyester mooring lines
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DOI：
10.1016/j.oceaneng.2008.09.004
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发表时间：
2008-12
影响因子：
5
通讯作者：
A. Tahar;Moo-Hyun Kim
中科院分区：
文献类型：
--
作者：
A. Tahar;Moo-Hyun Kim
提出了一种基于聚脂系泊绳的深水浮式平台耦合动力分析的理论和数值工具。该配方允许相对较大的伸长率和非线性应力-应变关系，如通常观察到的聚酯纤维。系泊线动力学基于杆理论和有限元方法，控制方程用广义坐标系表示。原始的杆理论[Nordgren， r.p., 1974]。弹性杆运动的计算方法。应用力学学报，41,77 - 780]的推广，以允许更大的伸长率和非线性应力-应变关系。聚酯的动态模量是根据一个经验回归公式提出的[博斯曼，r.l.m., Hooker， J., 1999。聚酯系泊绳弹性模量特性研究。见：海上技术会议论文集，OTC 10779。Houston, Texas]，其中轴向刚度不是恒定的，而是取决于加载条件。进行了两个案例研究，即张力浮标和带有聚酯系泊线的经典桅杆的静态和动态行为。将时域仿真结果与原杆理论进行了系统比较。对大伸长率和非线性应力-应变关系的影响分别进行了评估。可以看出，聚酯线的平均偏置、运动和张力可以不同于原始的线弹性线的杆理论。
A theory and numerical tool are developed for the coupled-dynamic analysis of a deepwater floating platform with polyester mooring lines. The formulas allow relatively large elongation and nonlinear stress–strain relationships, as typically observed in polyester fibers. The mooring-line dynamics are based on a rod theory and the finite element method (FEM), with the governing equations described in a generalized coordinate system. The original rod theory [Nordgren, R.P., 1974. On Computation of the Motion of Elastic Rods. Journal of Applied Mechanics, 41, 777–780] is generalized to allow larger elongation and nonlinear stress–strain relationship. The dynamic modulus of polyester is modeled following an empirical regression formula suggested by [Bosman, R.L.M., Hooker, J., 1999. The Elastic Modulus Characteristic of Polyester Mooring Ropes. In: Proceedings of the Offshore Technology Conference, OTC 10779. Houston, Texas], in which the axial stiffness is not constant, but depends on loading conditions. Two case studies, the static and dynamic behavior of a tensioned buoy and a classic spar with polyester mooring lines, are conducted. The time-domain simulation results are systematically compared with those from the original rod theory. The effects of large elongation and nonlinear stress–strain relations are separately assessed. It is seen that the mean offset, motions, and tension with polyester lines can be different from those by original rod theory with linear elastic lines.