Strange Nonchaotic Dynamics of Nonlinear Ship Rolling in Regular Beam Seas and Stochastic Wind
Based on a single-degree-of-freedom ship sailing in regular beam seas,the nonlinear rolling e-quation is established.The Runge-Kutta methods is used to solve the differential equation of motion,and the bifurcation diagram is plot by Poincaré surface of section.The process of different periodic attractors transforming into strange nonchaotic attractors under random wind excitation is studied by numerical simulation.It is found that a larger random excitation intensity is required to induce SNAs when the pa-rameter is varied further from the chaotic range.The maximum Lyapunov exponent is used to verify the nonchaotic characteristics of the attractors,and singular continuous spectrum and the trajectories in the complex plane can demonstrate the strange property of the attractors.