Worst Sea - Best Sea Wave Group Spectra from Random Sea States

The paper presents a proposition called the worst sea-best sea (WS-BS) method that intends to identify wave group spectra that yield time series that lead, respectively, to the highest wave group excitation (worst sea) and the smallest wave group excitation (best sea) to the second order slowly varying response for a floating structure model submitted to random waves in a wave basin. The methodology is based on the estimation theory. Based on the fact that even with the same wave spectrum it is possible to devise different wave group spectrum, the paper proposes a method to identify the WS-BS time series. Both simulations and concrete model testing are shown indicating the feasibility of the approach.