基于等效刚度法优化的风力机叶片刚度计算

Calculation of wind turbine blade stiffness based on equivalent stiffness method optimization

风力机叶片刚度由于非线性且截面变化程度大的特点,针对叶片建模初期刚度的评估问题通常采用刚度展项分布图体现叶片刚度,存在评估叶片刚度的参考参数不够直接、宏观的问题。基于变刚度梁挠度计算的等效刚度法,将叶片等效成变截面悬臂梁,根据叶片特征合理选取边界条件,以叶片建模的截面数据特点为基础,优化原始等效刚度法的计算方式,使该方法更加贴合叶片模型,从而适用于叶片,达到方法优化的目的。利用ANSYS有限元软件进行叶片的预应力模拟实验,得出叶片的挠度模拟数值,以该模拟计算的挠度值为参考,验证优化后方法的有效性。结果表明:优化后的等效刚度法得到的刚度值,在低均布载荷值22.5 Pa下理论计算的挠度值与试验挠度值的误差达到9.68%,减小原始方法计算的误差贴近叶片模型,可用于叶片刚度估算,为叶片的刚度计算提供新方法。

Wind turbine blade stiffness due to the characteristics of nonlinear and big section of variations,for modeling the initial stiffness assessment questions usually adopt stiffness elements distribution.This article is based on the equivalent stiffness method of variable stiffness of beam deflection,the leaves reduced to equivalent variable cross-section cantilever beam,according to the characters of blade selection reasonable boundary conditions.Based on the cross section data characteristics of blade modeling,optimization of the original the calculation of equivalent stiffness method,make the method more joint blade model,which applies to blades,to achieve optimization.The use of ANSYS finite element software for blade of prestressed simulation experiment,draw a blade deflection simulation numerical to the simulation calculation of the deflection value for reference,to demonstrate the effectiveness of the optimized method.Results show that the optimized equivalent stiffness method to get the stiffness value,under the uniformly distributed load at a low value of 22.5 Pa deflection of theoretical calculation value and experimental value of deflection error of 9.68%,reduces the error of the original method to calculate and close to the blad model,can be used in the blade stiffness estimation,provides a new method for blade stiffness calculation.