Applications of finite-time Lyapunov exponents to the study of capsize in beam seas

Abstract

This paper demonstrates the use of finite-time Lyapunov exponents (FTLE) for the detection of large amplitude roll motions and capsize. The study is conducted for a simple, single degree of freedom model of the Edith Terkol in regular and random beam seas. The effectiveness of the FTLE technique is qualitatively compared to a scalar ship motion metric based upon the 'energy index (EI)' concept used for real-time identification of quiescence. © Springer Science+Business Media B.V. 2011.