Nonlinear random response of ocean structures using first- and second-order stochastic averaging (Q1362156)

The authors suggest a unified second-order stochastic averaging approach to dynamic systems with weak stiffness and inertia nonlinearities. They present a response analysis of nonlinear ocean structures subjected to random waves. The equations of motion and the first- and second-order averaging methods are used to determine the first mode response statistics and stochastic stability. Nonlinear problems such as noise-induced transition and on-off intermittency are examined for the case of multiplicative noise. The results are compared with those obtained by Gaussian and non-Gaussian closures and by Monte Carlo simulation. The influence of parametric excitation and hydrodynamic forces on the response characteristics is described in terms of system parameters.