Energy Distribution in a Flexible Marine Structure with Passive Mass Damper

The modeling and numerical solution for berthing a ship to a nonlinear flexible marine structure equipped with a passive tuned mass damper are studied. For simplicity; rotations and hydrodynamic interaction between the platform and the ship are ignored and constant added mass is assumed. Fenders and piles are represented by nonlinear springs. Internal and external damping forces are assumed as functions of velocity. In the numerical analysis, Wilson-θ method which requires a reasonable computer time for design purposes is used with the state vector concept. It also takes into account nonlinear damping, nonlinear elastic and plastic behavior of the material and the absorbed energy loss due to the hysteresis, which is important for the design of modern fenders. In addition to fenders, passive tuned mass dampers are placed on the flexible structure. The effects of the tuned mass damper on the system response and energy distribution are investigated numerically for the linear and nonlinear cases and the results are discussed.