变分渐近梁截面分析方法在叶片分析中的应用

The Application of Variational Asymptotical Beam Sectional Analysis Method in Analysis of HAWT Blades

针对非均匀的、初始弯扭的各向异性玻璃钢叶片, 由几何非线性的3维弹性理论导出了常规的有限单元横截面分析公式. 基于旋转张量分解的概念, 得到了由1维广义应变与3维翘曲位移表示的3维应变场. 根据1 维应变, 用变分渐近方法建立翘曲位移, 然后可以得到具有任意几何形状和材料特性的玻璃钢叶片的横截面刚度. 作为应用实例, 计算了1 5 MW变速恒频风力机玻璃叶片截面剪切中心位置分布和截面刚度矩阵.

In this paper,a generalized finite-element-based cross-sectional analysis for nonhomogenous,initially curved and twisted,anisotropic GRP blades is formulated from geometrically nonlinear,three-dimensional(3-D)elasticity.The 3-D strain field is formulated based on the concept of decomposition of the rotation tensor and is given in terms of one-dimensional(1-D)generalized strains and a 3-D warping displacement.The warping is found in terms of the 1-D strains via the variational-asymptotical method(VAM)and then cross-sectional stiffness for a GRP blade with arbitrary geometry and material property can be obtained.As an application case,the cross-sectional shear center location distributions and some cross-sectional stiffness matrices of a 1.5 MW variable speed pitch regulated wind turbine GRP blade are calculated using the accompanying engineering software(VABS,Variational Asymptotic Beam Section Analysis).