LOW FREQUENCY MOTIONS OF FLOATING BODY WITH ASYMMETRIC MOORINGS

This paper treats the low frequency motions of floating body with asymmetric moorings. The phenomena could be grasped with use of the ready made numerical simulation code for the motions of floating body with arbitrary moorings or in the tank test. However the fundamental characteristics have not been clarified yet. By using a.simple numerical model, the parametrical study of the appearance of sub-harmonic motion is done. As the results, it is found that the sub-harmonic motion appears depending on the degree of the mooring asymmetry, that is the ratio of the restoring force coefficient in one side to the other side. And then the chart for judging the possibility of low frequency motion is presented.