Interaction of Load Analysis and Structural Design of Offshore Wind Turbines

The paper presents the necessary considerations for the determination of design loads for offshore wind turbines (OWTs) and OWT support structures. The design of OWTs strongly depends on the environmental conditions such as wind and wave data, ambient temperatures and soil conditions. Load analyses for OWTs are generally done using sophisticated simulation tools which consider the turbulent wind conditions as well as the structural dynamics and the operational behavior of the turbine. Compared to wind turbines onshore, wave loads are an additional element that needs to be considered. Experience shows that the natural frequencies of the support structure highly influence the design loads on the system due to excitation by the rotor. Therefore, the load analysis in combination with optimization of the support structure is an iterative process. A close cooperation between the designing engineers of turbine and support structure is definitely required. The calculation procedure will be presented as well as results from a sample calculation for a typical configuration.© 2006 ASME