Extreme response prediction for nonlinear floating offshore structures by Monte Carlo simulation

The paper describes a method for the prediction of extreme response statistics of floating offshore structures subjected to random seas by Monte Carlo simulation. The particular case of the horizontal surge motions of a tension leg platform is considered, taking into account both the first order, wave frequency and the second order, slow-drift motions. The advantage of the Monte Carlo method is its simplicity and versatility, which allows us to account for the effect of time-variant wave-drift damping, as well as nonlinear mooring characteristics without noticeable increase in the computational complexity. It is demonstrated in this paper that the commonly assumed obstacle against using the Monte Carlo method for estimating extreme responses, i.e. excessive CPU time, can be circumvented, bringing the computation time down to quite acceptable levels.