Studies Of Mooring Dynamics In Deepwater And Application In Coupled Analysis With Floating Structures

Floating offshore platform is the main form of floating structures used in oil exploration in deep water. And its analysis coupled with mooring systems under wind,wave and current forces has been the focus of ocean engineering since the moment it came into being. At the beginning the dynamic analysis method of mooring systems is studied,for which the slender rod method is explicitly introduced. For the numerical solution, the Newmark-β iteration method is presented and discussed. And then a few examples with analytical solutions are used to validate the numerical method. As to the dynamic analysis problem of polyester mooring lines,a visco-elastic model for polyester materials is introduced, which is added into the motion and control equations. For this new model,numerical solution is discussed and verification is done as well. At the end of this paper,the dynamic analysis algorithm of mooring lines is combined with the platform program based on the asynchronous coupled analysis method of moored platforms, bringing the coupled analysis of mooring lines and floating structures in deep water into realization.With this coupled analysis program, the analysis of a semisubmersible platform and a single point moored FPSO is carried out. Through this two examples, the numerical method is validated, and the dynamic analysis of mooring lines developed in this paper is applied to the coupled problem of floating structures in the engineering filed.