آنالیز هیدرودینامیکی سکوهای شناور با پایه های کششی

Among compliant offshore platforms, tension leg platforms (TLP) are referred to, as hybrid structures. This kind of platforms resemble to ordinary semi submersibles when their serge, sway and yaw motions are considered, since they are compliant whereas with respect to pith, roll and heave motions they respond more like a fixed platform rather than a floating body. This paper presents a method to analyze and evaluation of hydrodynamic forces of a regular simple wave on a TLP and a general solution to expand the method to be applied for a randomly changed water surface with a known spectrum e.g. pierson-Moskowitz. This analysis was made, using a 3D model with 6 coupled degree of freedoms. Stiffness of mooring system and drag force are assumed to non-linear and the effect of diffraction and radiation are neglected. Hydrodynamic forces and response were modeled, using modified Morison equation. The dynamic behavior of mooring lines and hydrodynamic forces on tensioners were neglected. The resulting equation was solved in time domain by Newmark-Beta algorithm.