Effect of global climate change projections on fatigue lifetime of permanently moored floating offshore structures

The design of floating offshore structures requires long-term wave data to estimate their fatigue lifetimes, because waves loadings are considered as the main source of fatigue damage. These sea-state data are mainly obtained through past measurements and assumed to be representative of the wave climate which the offshore structure is expected to encounter. This assumption however includes a lot of uncertainties induced by the climate change. The service lifetime of floating offshore structures is usually more than 20 years. The climate change may significantly affect the properties of sea states. If the wave climate is changed, the fatigue assessment at design stage may overestimate or underestimate the cumulative fatigue damage during service life. Therefore, the effect of climate change on the long-term wave loading and consequently on the fatigue assessment should be considered.