Noisy Nonlinear Motions of Moored System. II: Experimental Study

Abstract

An experimental study of a nonlinear moored structural system subjected to monochromatic wave excitations with random perturbations is reported in this paper. Sources of nonlinearity in the system include large geometric configurations and wave-induced quadratic drag. Random perturbations in the waves are approximated by linearly filtered white noise. An analytical model derived in Part I to assimilate the noisy nonlinear response is validated by good agreements shown in comparisons of simulated and experimental results in both time and frequency domains. System parameters of the analytical model are identified based on the experimental data. Noise effects on the nonlinear responses are examined. Experimental results indicate that the presence of random noise bridges the domains of multiple coexisting response attractors, and transitions among the multiple steady states are observed as analytically predicted in Part I.