由 (ax)。+m(zx) (xx)+m(a,) 1(a)0=f fx=-6 xy/x 0 f=0 x= f=6 C 丿x=L y f,=0 解决矩形截面梁纯弯曲问题 y由： ( ) ( ) ( ) ( ) y s y s xy x s x s xy m f m f + = + =       ( ) ( ) ( ) ( ) y x L xy x x L x y x xy x x x f f f f = = − = − = = = = =     0 0 1 1 0 6 = = y x f f ay 0 6 = = − y x f f ay 0 2 h 2 h x y L 解决矩形截面梁纯弯曲问题