风力机叶片分布力函数加载方式有限元分析

FEM SIMULATION OF DISTRIBUTED FORCE FUNCTION LOADING APPLIED ON WIND TURBINE BLADE

在复合材料风力机叶片有限元模型的基础上,给出一种新型的分布力函数加载方法,沿叶片展向将各截面的挥舞集中力和摆振集中力转化为叶片展长不同位置的分布力函数,同时考虑翼型的压力分布特性将弦向的单点集中力转化为分布力函数,从而将叶片展向分布力和弦向分布力加载于叶片有限元模型的外壳轮廓面上。通过有限元分析分布力函数加载方式下的叶片挠度、静强度和稳定性,与叶片各截面的集中力载荷通过多点约束的加载方式作用于叶片节点上的结构特性相比较,结果表明,采用分布力函数表达式加载能真实模拟叶片的受力特性,为叶片结构设计和结构校核提供了一种新的加载方法。

Based on the FEM model of composite wind turbine blade, a novel loading-distributed force function was proposed. The flapwise concentrated force and edgewise concentrated force on the blade sections were transferred to the distributed forces along the span, and concentration load on the chord were also transferred to the distributed force by considering the pressure distribution over the airfoil. Both of the distributed forces on the blade span and section chord were applied on the outline of the FEM model. The deflection, strength and stability of the blade due to the distributed forces were analyzed and compared with the results from traditional multi-point constraint concen- tration loading by the FEM computation, demonstrating that this novel loading way can make a better match of prac- tical load-carrying capability in terms of structural property. It provides an efficient way for blade structural design and check.