小型风力发电机叶片模态特性分析

以800W水平轴风力发电机叶片为对象，研究其叶片的模态特性．从理论上介绍了应力刚化和旋转软化对叶片固有频率的影响，并给出了考虑应力刚化和旋转软化效应的振动方程；利用ANSYS软件建立了有限元模型，分别对风力发电机叶片在仅考虑应力刚化或旋转软化时，以及同时考虑应力刚化和旋转软化时的模态特性进行了计算分析．计算结果表明：应力刚化对固有频率的影响比旋转软化大；仅考虑旋转软化时，叶片的固有频率比零旋转角速度时低；而综合两者的影响时，叶片的固有频率比零旋转角速度时高．

The modal characteristics analysis of the small wind turbine blade

The modal characteristics of the blade for 800 W horizontal axis wind turbine （HAWT） were investigated in this paper. Effects of the stress stiffening and the spin softening on the blade natural frequency were theoretically discussed respectively, and the vibration equation considering both effects was given. A finite element model of 800 W HAWT blade was established with the ANSYS software, and the blade modal analysis which only considers the stress stiffening or the spin softening was carried out. In addition, the blade modal analysis which simultaneously considers the stress stiffening and the spin softening was also conducted. The results showed that the influence of the stress stiffening on the natural frequency is greater than that of the spin softening. The blade natural frequency when only considering the spin softening is lower than that when the blade in static. The blade natural frequency when simultaneously considering the stress stiffening and the spin softening is higher than that when the blade in static.