Dynamic analysis of tension leg platform for offshore wind turbine support as fluid-structure interaction

Abstract

Tension leg platform (TLP) for offshore wind turbine support is a new type structure in wind energy utilization. The strong-interaction method is used in analyzing the coupled model, and the dynamic characteristics of the TLP for offshore wind turbine support are recognized. As shown by the calculated results: for the lower modes, the shapes are water’s vibration, and the vibration of water induces the structure’s swing; the mode shapes of the structure are complex, and can largely change among different members; the mode shapes of the platform are related to the tower’s. The frequencies of the structure do not change much after adjusting the length of the tension cables and the depth of the platform; the TLP has good adaptability for the water depths and the environment loads. The change of the size and parameters of TLP can improve the dynamic characteristics, which can reduce the vibration of the TLP caused by the loads. Through the vibration analysis, the natural vibration frequencies of TLP can be distinguished from the frequencies of condition loads, and thus the resonance vibration can be avoided, therefore the offshore wind turbine can work normally in the complex conditions.