This paper focuses on reliability assessment of Wave Energy Device (WED) substructures with respect to fatigue loading. Failure due to fatigue is an important failure mode of most offshore structures. The focus of the fatigue reliability assessment is in this paper on welded details in steel substructures.
The methodology is illustrated using the Wavestar prototype located at Hanstholm (DK) as a case study. The stochastic model presented can be used for reliability assessment and for calibration of Fatigue Design Factors (FDF) of wave power plant substructures. The fatigue life is modeled using the SN approach. Design and the limit state equations (LSE) are established for the accumulated fatigue damage where real sea state data is taken into account.