Validation and applicability of an integrated load simulation method for offshore wind turbines with jacket structures

An integrated simulation model has been further developed and applied, which facilitates the combination of the wind turbine and the support structure in one direct solution by coupling the equations of motion during runtime. This ensures full dynamic interaction of the models without further simplification of the original models. Two applications have been realised. The simulation method is validated against measurements from a commercial offshore wind turbine. The measurement campaign is carried out in the wind farm Alpha Ventus, the first commercial wind farm in the German North Sea. The considered wind turbine is a Senvion 5M installed on a jacket in 28m water depth. The validation considers mainly the strain gauge measurements from the rotor blades, the tower and the jacket substructure at different operational states of the wind turbine. High resolution data and the derived statistical parameters are taken into account for the validation. The results consider natural frequencies, quasi-static loadings, time series, statistic parameters, damage equivalent loads and rainflow count distribution. Correlated wind and wave conditions from a nearby met-mast are used directly in the simulation model. The final part of the thesis addresses the distinctions between different simulation approaches compared to the developed fully-integrated approach for offshore wind turbines with jackets. The three alternative models differ mainly in the accuracy of the jacket subsystem or the limited dynamic interaction between wind turbine and support structure.