Mooring Dynamics Study Of Floating Body Based On The Coupled Analysis

Mooring system is one of the important part which guarantees the safty of the ocean engineering structures. And it is one of the important structures that resist the platform from the efficiency of the wind, wave and current. The calculation model which is based on the principle of slender rods can simulate the random geometry configuration of the mooring line in the three-dimension. The interaction between the mooring system and the floating body which is called the coupled efficiency. The coupled efficiency is one of the significant factors during the designing of the platform and the mooring system.First of all, the quasi-dynamic coupled analysis of the floating body-mooring system is described. Then some calculation researches on the motion characteristics have been done by using a software which is based on the quasi-dynamic coupled analysis. The research on the mooring line is under the theory of the slender rods. The motion equations of the slender rods have been derived by analyzing the equilibrium of the micro-unit. Using the Newton iteration method and Adams-Moulton method to solve the discrete form equations of the static and the dynamic analysis respectively. Linear spring is used to simulate the flat seabed. The contact problem between mooring line and the seabed has been studied. The motion characteristics in six degrees of freedomof the floating body are described. And the motion equation is solved under the time domain. After the above researches on the floating body and the mooring system, the coupled analysis between them is lucubrated. The spring and the damper are used to simulate the connection of the platform and the mooring line. The characteristics of the platform and the mooring line are solved in time domain synchronously.After get the stiffness martrix of the differential equation under the matrix form, the calculation program of the static and dynamic analysis is complied by using the Fortran language. The fully coupled analysis software HARP is used to calculate the platform-mooring system. And compare the results of fully coupled analysis with the quasi-dynamic analysis software Ariane7. The significance of the coupled efficiency between platform and the mooring system has been proved, and the application scope of these two methods has been researched.