DYNAMIC RESPONSE OF A MOORED SEMISUBMERSIBLE IN SHORT-CRESTED WAVE FIELDS

Wind generated sea states are more accurately modeled by short-crested wave elds. Whether or not these short-crested waves can induce larger response amplitudes in oating o shore structures is of great concern to o shore engineers. In this paper, the hydrodynamics of a moored semisubmersible in short-crested wave elds is investigated. Morison-based motion equations with nonlinear damping terms are used to analyze the dynamic behavior of the structure. A generalized three-parameter short-crested wave eld is introduced as the incident wave. The e ect of transverse phase lag, wave propagation angle and di erent ratios of in-line and transverse wave numbers are studied on the force and response amplitudes of the oating structure. Finally, the results are compared to that of the long-crested wave elds and critical cases are speci ed.