渤海海域单柱三桩式海上风电结构冰激振动分析

Analyses on ice induced vibrations of a tripod piled offshore wind turbine structure in Bohai Sea

针对渤海某区域以单柱三桩式结构为支撑的海上风电系统进行了冰激振动分析。首先模拟风电结构具有显著动力特性差异的主-从式结构特征,根据工程场址海域冰情条件,设置了合理的海冰分析工况,随后依据概化冰力函数确定作用于风电基础结构上的动冰力时程,开展全时域瞬态动力分析。通过对计算结果的详尽分析,选定表征冰与风电结构相互作用进程的综合控制因子Ic,建立基于综合控制因子的冰振事件区划及其出现概率的预判方法。相关方法将为渤海海域风电工程结构冰激振动问题的预判与评估提供参考。

The analysis on ice induced vibration for a tripod piled offshore wind turbine structure in Bohai Sea was carried out. Firstly,the nonlinear characteristics of the structure,i. e. having significant differences in the dynamic characteristics of the parallel structures,were accurately simulated. Secondly,reasonable calculation cases were set up according to the site conditions of sea ice. Finally,time histories of ice loads were obtained using dynamic ice load function and transient dynamic analysis was subsequently carried out. Based on thorough analyses of the calculating results,an important factor that represents the interaction process between ice and structure was established and named as the integrated control factor（ I_c）. Furthermore,the ice induced vibration events were divided into several regions in consistence with Ic. The calculating method for estimating the occurring probabilities for the regions was also given. The methods presented in this paper will provide important references for the judgements and evaluations on the ice induced vibrations of offshore wind turbine structures in Bohai Sea.