单点系泊船舶的动态分岔特性研究

Research on the dynamic bifurcation characteristics of single point mooring vessels

研究了潮流作用下单点系泊船舶的动态分岔特性。应用高维微分动力系统Hopf分岔的直接代数判据,得到了潮流作用下单点系泊系统发生Hopf分岔的充要条件,并应用于油轮系泊运动的Hopf分岔研究。以潮流速度和系缆长度为控制参数,在参数平面上给出了Hopf分岔集,应用数值仿真计算检验了理论分析结果,两者相当吻合。由此在参数空间中确定了潮流作用下单点系泊船舶的非线性动力学特性,为系泊系统设计参数的选择提供了理论依据。

The dynamic bifurcation characteristics of single point mooring systems under the action of tidal current is investigated. By using the direct algebraic criterion for Hopf bifurcation of differential dynamical systems, sufficient and necessary condition for Hopf bifurcation of single point mooring systems subjected to tidal current is established and then used to study the Hopf bifurcation of a SPM moored tanker. Local bifurcation set and stability charts of the SPM moored tanker are obtained in the bifurcation parameters space, while current velocities and mooring line lengths are defined as bifurcation controlling parameters. Comparing the results of the computer simulations and theoretical conclusions a good agreement is found. According to these results, the dynamical characteristics of a mooring system could be clarified clearly, which could provide a kind of scientific basis for the choice of the system parameters in the design stage of mooring systems.