ABSTRACT
Offshore wind structures are subjected to complicated loads and load effects, which demand comprehensive numerical modelling representation of the physics. There is interdependence between loads, load-effects, and structural strength. This calls for transparent explicit safety requirements based on design by direct analysis and first principles of hydrodynamic and aerodynamic loads and their effects on offshore wind turbine structure. Different offshore wind turbines with different support structures would have different reliability levels due to differences in uncertainties in load effect (responses) and resistance in relation to the current design values. This paper deals with the monopile offshore wind turbine design format from a structural reliability point of view. The effect of the definition of characteristic values and model uncertainties in loads and resistance on the reliability measures, and hence the safety factors, are studied. The aim is rather to address some possible directions of further design code developments.
