Fast Spectral Rainflow Fatigue Damage Assessment Under Wideband Multipeak Loading

摘要

This paper presents a method for a fast assessment of the fatigue damage under complex metocean climate conditions. That method is based on a spectral formula with the advantage of providing the damage of a multipeak spectrum in terms of the damages and the spectral moments of its components (i.e. corresponding to each of its peaks). The method is applied to the assessment of fatigue damage of an FPSO subjected to the effect of local pressure near the waterline from wave loading in the West Africa area. The damage computed using the proposed method is compared to a reference solution given by time-domain simulations on the metocean database sea states. It is shown that the method allows to simply take into account a complex metocean climate description for fatigue analysis. The results do not completely meet the reference solution, but this is essentially due to difficulties in the reconstruction of the long-term metocean climate.