Uncertainty Modeling and Fatigue Reliability Assessment of Offshore Wind Turbine Concrete Structures

In this paper, the propagation of uncertainties related to structural, environmental and fatigue damage model parameters is evaluated by performing Monte Carlo fatigue simulations of a concrete foundation for offshore wind turbines. Concrete fatigue damage models are formulated based on the S-N approach, where the resistance model uncertainty is calibrated against experimental fatigue tests. Results indicate that the resistance model uncertainty governs the concrete FLS assessment. This underlines the importance of improving estimates of model uncertainty by conducting experimental fatigue tests at lower stress cycle amplitudes and at different mean stress levels.