Structural response of deck structures on the green water event caused by freak waves

Freak waves are huge and unexpected surface waves in the ocean which usually lead to severe destructions to ships and offshore structures. Green water is one of the most commonly observed phenomena when ships and marine structures encounter with freak waves. As a result, freak waves will likely to create significant wave impact on the deck structures. However, the existing researches on the interaction between freak waves and marine structures are still inadequate. In order to investigate the green water phenomenon caused by freak waves and the structural response of the deck, a 2-D numerical wave flume is built in which a nonlinear freak wave based on the Peregrine breather solution is generated. By setting an elastic bare deck horizontally in the flume, the fluid-structure interaction (FSI) is considered during the green water event. To approximate the complicated real decks, a deck model containing intermediate elastic supports are used. The simulation results include the snapshots of the entire green water process, the pressures of the fluid on the deck and the displacements of the elastic decks analyzed with the fast Fourier transformation (FFT) and the wavelet transformation method. By comparing the results of the rigid deck, the elastic bare deck and the elastic deck with intermediate elastic supports, advisable conclusions are drawn.