Optimal Vibration Control for Offshore Structures Subjected to Wave Loading with Input Delay

The optimal vibration control of a jacket-type offshore platform system with input delay by using active mass damper (AMD) is considered. The linearized Morison equation is employed to estimate wave-induced forces, the dominant loads that offshore structures are subjected to, which can be taken as harmonic excitation for the system. Firstly, an Artstein model reduction method is applied to reduce the system free of delay. Secondly, a Feedback and Feedforward (FFOC) algorithm is brought forward to damp the forced oscillation in an optimal fashion. Finally, a numerical example of the FFOC law for a jacket-type offshore platform by using of AMD is studied. The simulation results show the algorithm proposed is efficient.