21 Spectral Analysis of Finite Amplitude Random Wave Loadings

The spectral analysis of finite amplitude random wave loadings are studied on this paper by means of nonlinear spectral analysis. Under the assumption of the first order wave profile being zero-mean Gaussian process, the random wave spectra of finite amplitude waves are given. The drag force is extended into power series of velocity in order to solve the loading spectra of the finite amplitude random waves. The loadings of the finite amplitude random waves are then expressed as nonlinear compositions of the first order wave profile and its derivatives. The numerical computations are carried out and the spectra of wave forces and wave moments are given.