Analyses on Low Cycle Resonance of Ship in Astern Seas

Low cycle resonance occurs due to the dynamic variation of righting arm with respect to the relative position of ship to waves. The dynamic variation depends on the encounter period of a ship in astern seas. This paper discusses on the following items. (1) An analytical expression of GZ curves varying with respect to the relative position of ship to waves. (2) Non-linear equation of motion describing low cycle resonance. (3) The effects of righting arm, stability range and encounter period on low cycle resonance.