Rotor blades are the most important and most expensive part of a wind turbine; their dynamic behavior is of great significance for maintenance planning and safe operation. In this study, the effect of mistuning on the vibration modes of rotor blades was investigated, with a focus on the mode localization of linear time-varying wind turbine rotors. And the significance of the work lies in finding that the mode localization may aggravate the blade damage and potentially reduced fatigue life of the blade. The rotating blades were approximated as cantilever Bernoulli–Euler beams, and the flapwise and edgewise modes of each blade were considered. The Lagrangian method was employed to derive the linear time-varying dynamic equations of the wind turbine rotor. A wind turbine rotor was mistuned because of slight fluctuations in the blade stiffness; subsequently, Floquet analysis was employed for modal decomposition of a mistuned wind turbine rotor, and the mechanism of mode localization was examined in depth. Numerical simulation results indicated that slight mistuning of a single blade is sufficient for triggering mode localization. The effects of the magnitude of the blade mistuning and rotor speed on the severity of mode localization were analyzed. Finally, different quantitative measures were considered for characterizing the degree of mode localization in mistuned wind turbine rotors.

中文翻译：

---

线性和周期性时变失谐风轮的模式定位

转子叶片是风力涡轮机中最重要和最昂贵的部件；它们的动态行为对于维护计划和安全操作具有重要意义。在这项研究中，研究了失谐对转子叶片振动模式的影响，重点是线性时变风力涡轮机转子的模式定位。而这项工作的意义在于发现模态局部化可能会加剧叶片损坏并可能降低叶片的疲劳寿命。旋转叶片近似为悬臂伯努利-欧拉梁，并考虑了每个叶片的襟翼和边缘模式。采用拉格朗日方法推导出风轮机转子的线性时变动力学方程。由于叶片刚度的轻微波动，风力涡轮机转子失谐；随后，采用 Floquet 分析对失调的风力涡轮机转子进行模态分解，并深入研究了模态定位机制。数值模拟结果表明，单个叶片的轻微失调足以触发模式定位。分析了叶片失谐幅度和转子速度对模式定位严重程度的影响。最后，考虑了不同的量化措施来表征失谐风力涡轮机转子的模式定位程度。分析了叶片失谐幅度和转子速度对模式定位严重程度的影响。最后，考虑了不同的量化措施来表征失谐风力涡轮机转子的模式定位程度。分析了叶片失谐幅度和转子速度对模式定位严重程度的影响。最后，考虑了不同的量化措施来表征失谐风力涡轮机转子的模式定位程度。