Flexıble body dynamıcs of offshore wınd turbıne under extreme loadıng condıtıons
The flexible body of offshore wind turbine is exposed to self-weight of turbine together with wind, wave and earthquake induced by the external forces. In order to be able to carry out the dynamic analysis of this body, wind forces represented in accordance with the various standarts, wave forces expressed by using different wave theories in terms of water depth and different wave parameters, and the graphics or digital data on earth motion acceleration recorded during earthquake can be taken
... uake can be taken into account within unique model to be developed for each case. In this study, maximum wind force by Turkish Technical Standarts (TSE498), wave force based on linear theory and earthquake acceleration recorded for Duzce province in western Turkey are used for solving the dynamic behaviour of offshore wind turbine. Unique model is also developed at the scope of this study. Steady wind and unsteady wave-induced oscillations along flexible body are analytically and numerically investigated. In analytical model, they are specified according to using the elastic curve equation for assumption of initial shape function needed and analyzing with the Single-degree of freedom system (SDOF). In case of numerical analysis, the Stress Analysis Program (SAP2000) based on the Finite Element Method is used. Finally, the oscillations on the unique model of flexible body are expressed in analytical form by SDOF and in numerical form by SAP2000. The results obtained from both analyses are also compared. It is seen that the analytical model developed by shape function-based assumptions give us the spatial and temporal oscillating function within the tolerable convergence. On the contrary, the results of numerical analysis execute the displacements changing instantanously and positionally along flexible body except for functional expression.