Roll stability catastrophe mechanism of a flooded ship on regular sea waves

Based on a typical one-free-degree ship roll motion equation, the cusp catastrophe model is built including the bifurcation set equation, splitting factor‘u’and regular factor‘v’, where both‘u’and‘v’are further expressed with typical flooded ship parameters. Then, the roll catastrophe mechanism is analyzed mainly by means of‘u’, under the given parameters of a typical trawler boat. The aim of this research is to reveal the mutagenic mechanism of the roll stability and provide a reference for improving ship roll stability.