耦合加载方式下复合材料叶片的预应力模态分析

针对大型风力机叶片在静止和变速运转工况下,振动模态计算分析方法和转速对频率的影响进行了研究.建立了叶片有限元模型,静力分析时采用耦合加载方式;采用分块Lanczos法分析了叶片的模态,考察了叶片固有频率对预应力效应的敏感程度及稳定性,探讨了转速对叶片频率的影响程度,分析了预应力效应产生的原因.结果表明:叶片主要以挥舞和摆阵振动形式为主;预应力效应对叶片的固有频率产生了较大影响,随转速的不断增大叶片的固有频率也随之增大,且预应力效应对叶片挥舞刚度的影响程度大于摆阵刚度的影响.

Prestress modal analysis of composite blade under coupling loading method

The modal calculation and analysis method as well as the effect of the rotational speed on the natural frequency, for the large?scale wind turbine blade in static and variable speed running conditions were studied. In this paper, the finite element model (FEM) of wind turbine blade was also established. The coupling loading method was applied during stationary analysis. Lanczos method was used to analyze the modes of the blade. The effect of the pre?stressing on the natural frequency and the stability performance of the blade were investigated. Meanwhile, the effect of rotational speed on the natural frequency was discussed. The reason of the pres-tressing effect was also analyzed. The results showed that the modes of vibration were mainly flap?wise and edgewise motion for the wind turbine blade, and the pre?stressing effect has a significant effect on the natural frequency, where the natural frequency of the blade was also increased with the increasing rotational speed. Furthermore, the effect of pre?stressing effect on the flap?wise stiffness was greater than that of edgewise stiffness.