Behavior Characteristics of Hang Off Riser That Considers Oscillation of Floating Structure

A riser system has been used widely as the progress of ocean developments. The vibration is one of the most important problems from the safety aspect of a riser system. In this paper, we conducted the model experiment of a hang-off riser at the Deep-Sea Basin in the National Maritime Research Institute of Japan. Translational and rotational motions of the upper floating structure are simulated by the forced-oscillation device. The motion of the riser was measured using 3D video tracking system. Numerical analysis program for simulating the behavior of riser was also developed. This program used the improved Morison’s equation as a method of evaluating hydrodynamic force. The validity of this calculation method was verified through the comparison with the experiment results.