Wave-induced hydroelastic response of fast monohull displacement ships

High-speed ships are weight sensitive structures and high strength steel, aluminium or composites are preferred building materials. It is characteristic for these materials that they result in larger hull flexibility than more conventional materials. Therefore, for large fast ships the lowest natural frequencies of the global hull modes can be relatively low compared to the frequency of wave encounter.In the present paper the effect of hull flexibility on the wave-induced springing and whipping vibrations is investigated in stationary stochastic seaways. The calculations are performed using a quadratic strip theory formulated in the frequency domain and a fully non-linear time-domain strip theory. The hydroelastic response is thereby excited partly by resonance and partly by non-linear excitation. The calculations are carried out for a recent proposal for a fast monohull containership.