ESTIMATIONS OF TLP MOTIONS IN 2D USING ANALYTICAL METHODS

Tension leg platform (TLP) is one of the compliant offshore platforms which has designed and implemented in the last couple of decades for oilextraction. Large stiffness in heave, roll and pitch degrees of freedom of TLPs and their stability fit them to be used as the offshore wind turbines leg. Assumingsmall amplitude of motion for the platform, TLP behavior was modeled in the form of a mass-spring system, in this study. First order wave-induced motionis considered to be a linear combination of oscillations in still water and the motions of excitation forces on the fixed body. For the roll motion this presumption isnot valid as the large amount of energy is needed for motion development in most of the offshore structures [1, 2]. Mooring stiffness can be obtained based uponan elastic behavior system [4, 5, 6].