§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 =}=[Bls} N(r) q1(x) DIBNS) 或或、或JJ EA X SW= NSax+ MSkdx y so da N 0 dEy v(X =}[B[D1 e6g4) x u(x ={8[BDIx25 e66 V.= y=6+o((x δ}[DIk j q2(x) =65({5+N(x)) =68+。yNy(x)§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 D B M x N x =        ( ) ( )      e  = B  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)   1  2  3          = + l e e T We F d q x dx 0     ( )         = ( ) ( ) ( ) q x q x q x y x            = + l e T T Te We F N q x dx 0      ( )   (     ( ) ) 0 = + l e T Te   F N q x dx   = + l l Wi N dx M dx 0 0      dx M l N T y x              = 0       B DB  dx l T e Te  = 0              = l T e Te B D B dx 0    Wi = We           = l T e Te B D B dx 0      (     ( ) ) 0 = + l e T Te   F N q x dx        + l e T F N q x dx 0        = ( )  l T e B D B dx 0 