The warping is found in terms of the 1 - d strains via the variational - asymptotical method ( vam ) and then cross - sectional stiffness for a gpr blade with arbitrary geometry and material property can be obtained 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。