浮体与系泊系统的耦合动力分析

发布时间：2019-06-08 13:11

【摘要】：浮体与系泊系统的耦合动力分析对各种新型海洋平台和海洋结构物的应用具有重要意义。在浮体和系泊系统的时域耦合分析中,研究并提出了一种预报浮体和系泊系统非线性运动响应和缆索张力的分析技术。考虑瞬时物面变化引起的各种非线性因素,在时域内建立浮体的非线性运动方程并求解,其中,入射波力和静恢复力按瞬时物面条件计算,辐射力和绕射力按浮体在瞬时平均湿表面为平衡位置做简谐振荡运动来计算;考虑系泊缆索受到的非线性流体动力及大位移,采用三维弹性梁理论将缆索模型化,把缆索看作是等拉伸、等弯曲刚度的细长结构,并采用非线性有限元法对缆索的运动方程进行求解;将浮体的分析方法和系泊缆索的分析方法结合,建立了浮体和系泊系统非线性运动响应和缆索张力的耦合计算方法;对缆索,使用高阶单元,只需要较少的单元就可以得到收敛解;对耦合动力分析方程,采用隐式、显式混合的数值格式,最终将方程化为显式格式进行求解,并且合理排列和控制求解次序,这样大大提高了计算效率。对系泊浮体的固有周期、各种工况下大幅非线性运动、缆索张力等进行了计算,并进行对比研究,可以看出,该文的方法既适用于缆索小变形条件下,也适用于缆索大变形条件下浮体与系泊系统的耦合动力分析。
[Abstract]:The coupling dynamic analysis of floating body and mooring system is of great significance to the application of various new offshore platforms and structures. In the time domain coupling analysis of floating body and mooring system, an analytical technique for predicting nonlinear motion response and cable tension of floating body and mooring system is studied and proposed. Considering all kinds of nonlinear factors caused by the change of instantaneous object surface, the nonlinear equations of motion of floating body are established and solved in time domain, in which the incident wave force and static recovery force are calculated according to the instantaneous object surface condition. The radiation force and diffraction force are calculated according to the harmonic oscillatory motion of the floating body for the equilibrium position on the instantaneous average wet surface. Considering the nonlinear hydrodynamic force and large displacement of mooring cable, the cable is modeled by three-dimensional elastic beam theory, and the cable is regarded as a slender structure with equal tensile and equal bending stiffness. The nonlinear finite element method is used to solve the motion equation of the cable. Combining the analysis method of floating body with the analysis method of mooring cable, the coupling calculation method of nonlinear motion response and cable tension between floating body and mooring system is established. For cables, using high-order elements, only a few elements can be used to obtain the convergence solution. For the coupled dynamic analysis equation, the implicit and explicit mixed numerical scheme is adopted, and the equation is finally solved into an explicit scheme, and the order of solution is arranged and controlled reasonably, which greatly improves the computational efficiency. The inherent period of mooring floating body, large nonlinear motion under various working conditions, cable tension and so on are calculated, and it can be seen that the method in this paper is not only suitable for the condition of small deformation of cable, but also suitable for the condition of small deformation of cable. It is also suitable for coupling dynamic analysis of floating body and mooring system under large deformation of cable.
【作者单位】：海军工程大学舰船工程系;
【分类号】：U653.2;U661

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