为探究切出风速下风力机变桨故障叶片的载荷及动力学特征，利用FAST软件进行数值计算，发现载荷及叶尖位移分别为变桨成功叶片的13.6和14.2倍，可知变桨故障叶片极可能发生结构失效断裂事故。为改善结构力学性能，提出结合仿生方法及分形理论的新构型叶片，并通过有限元分析与原始叶片进行对比，其中载荷边界条件来自以数据库方式存储FAST计算结果的叶片17段载荷数据。结果表明：仿生分形叶片重量及叶尖位移分别比原始叶片减少23.4%和19.7%；同时，结构屈曲分析显示，仿生分形叶片一阶屈曲因子为1.858，比原始叶片提高33.6%，极大增加了叶片结构安全性。

To explore the load and dynamic characteristics of the wind turbine blade with pitch fault at the cutout wind speed,numerical calculations were carried out based on the FAST software.It was found that the load magnitude and the blade tip displacement were 13.6 and 14.2 times of the blade with pitch success respectively,which could be seen that structural failure and fracture of the blade with pitch fault were most likely to occur.In order to improve the structure mechanical properties,the new configuration blade combining the bionic method and fractal theory was proposed.It was compared with the original blade by using the finite element analysis,in which the load boundary condition was from the load data of 17 blade segments based on FAST code calculation results that were stored as the database.The result shows that the weight and tip displacement of the bionic fractal blade are reduced by 23.4% and 19.7% respectively,compared with the original blade.Moreover,the buckling analysis of the structure shows that the firstorder buckling factor of the bionic fractal blade is 1.858,which is 33.6% higher than the original blade,improving the safety of blade structure greatly.

TK83

国家自然科学基金（52006148，51976131）；上海“科技创新行动计划”地方院校能力建设项目（19060502200）