Uncertainties in loads for ships structures

Structural reliability analysis requires characterizing uncertainties in strength and loads for selected failure modes. The objective of this paper is to study the uncertainties associated with the vertical wave-induced bending moment on ship hull girders. Also, uncertainties in whipping effects are investigated. Spectral analysis was used to calculate the maximum life-time wave loads on a ship with and without whipping. This type of analysis requires knowing a set of basic random variables. The uncertainties in wave-induced and whipping bending moments were investigated using Monte Carlo simulation by randomly generating these basic random variables and calculating wave and whipping loads on a ship. A parameteric study was performed to investigate the effect of variability in these basic random variables on the uncertainties of wave loads.