Reliability analysis has been performed to assess the ultimate hull girder strength in longitudinal bending. A series of progressive collapse analysis is performed applying the Smith's Method on hull girders of Panamax bulk carrier, Aframax tanker and wood-chip carrier to evaluate the ultimate hull girder strength and its sensitivities with respect to design parameters. On the basis of the calculated results, the mean and the standard deviation of the ultimate hull girder strength are derived applying the Mean-Value First Order Second Moment (MVFOSM) Method. On the other hand, time-dependent nonlinear ship motion is calculated to obtain wave-induced bending moment applying the Strip Method with consideration of the influence of large motion, and the mean and the standard deviation of the extreme wave-induced bending moment are derived. Utilising these results of calculations, probability of failure and reliability index are calculated and the ultimate hull girder strength in longitudinal bending is assessed.
