A two-scale probabilistic time-dependent fatigue model for offshore steel wind turbines

Due to both wave and wind fluctuations, the steel foundations of offshore wind turbines are highly submitted to fatigue. To date, current methods of fatigue design proposed in the regulations are not devoted to structural optimization and to the consideration of time-variant hazards. We propose hence an incremental two-scale model of damage in order to follow the time evolution of the damage. This temporal evolution allows the updating of model parameters using records from Structural Health Monitoring. In this paper, we focus on Bayesian updating of damage parameters and sensitivity analysis of damage assessment to material parameters.