Abstract The flexible tower structure of offshore floating wind turbines is a crucial load-bearing component connecting the floating platform and wind turbine unit, and its structural dynamic response exhibits significant nonlinear characteristics and multiscale coupling effects under complex marine environmental loads. To accurately reveal the dynamic behavior of floating wind turbine towers, this study focuses on the flexible tower of a semi-submersible floating wind turbine. A nonlinear dynamic theoretical model based on Cosserat rod theory is established and discretized using the finite element method. The dynamic response characteristics of the tower under the concentrated loads from turbine blades are analyzed in depth. Furthermore, by comparing results from the theoretical model with independently developed numerical simulation programs, the accuracy and reliability of the theoretical model are validated. Additionally, the influence of element mesh density on the simulation accuracy and reliability of tower vibration modes, as well as the sensitivity of the dynamic response of the upper structure under various wind speeds, are systematically investigated. The findings of this study can provide reliable theoretical foundations and technical support for the optimal design and safe operation of offshore floating wind turbine flexible towers.
Jie Tian (Fri,) studied this question.