§15基于变形体虚位移原理的弯曲单元(自由式单元的单元分析 00016 q1(x) F EA X 3/72-2/l3/2-1/l B4JL 2/71/72 -2/721/78 (x)=M11+N2O2 v(x)=n202+N3O3+NSS5+N606 Se v(X x N2=1-322+25 u(x N3=l5-212+l2 WNIo l22+l5 N30N5§1.5 基于变形体虚位移原理的弯曲单元(自由式单元)的单元分析 E,A, I , l x e F1 F2 2 1 F5 F4 F3 F6 q (x) x q (x) y x y 1 2 e  1 e  2 e  3 e e  5  4 e  6 x u (x) v(x)                            − − − − =               6 5 3 2 3 2 3 3 2 2 4 3 2 1 2 / 1/ 2 / 1/ 3/ 2 / 3/ 1/ 0 1 0 0 1 0 0 0         l l l l l l l l 2 2 3 3 5 5 6 6 1 1 2 2 ( ) ( )       v x N N N N u x N N = + + + = + 2 3 6 2 3 5 4 2 3 3 2 3 2 1 3 2 2 1 3 2 1            N l l N N N l l l N N = − + = − = = − + = − + = −                   =       = 6 1 2 3 5 6 1 4 0 0 0 0 0 0    N N N N N N v u d                  = 2 1 1 2   d N N               =           = 6 5 4 2 3 2 1 1            e = N 