或N(5,m)=(1-55)(1+1m)(i=1,2,3 N,0:N,0:N,0:N,0 N(5,n) 010N20N30N4 思考题:这种单元是收敛的单元吗?为什么? 2.单元应力与应变 (}=[4d} 0/ax01/a/050 00/ 0y 1/b·0/0; 0/y/ax|1/b0/n1/ao/a5 }=[4[N(5,n)]G =[4[N[4[N2…lbF =[B[B…BJG}e [B]{       T e  = A N(,)            T T e = A N 1 A N 2   或 (1 )(1 ) ( 1,2,3,4) 4 1 Ni (,) = − i  +i  i =         = 1 2 3 4 1 2 3 4 0 0 0 0 0 0 0 0 ( , ) N N N N N N N N N   思考题:这种单元是收敛的单元吗?为什么? 2.单元应力与应变   A d T  =                     =                   =     1/ / 1/ / 0 1/ / 1/ / 0 / / 0 / / 0 b a b a y x y x A T        = N 1 N 2  N 4         e = B 1 B 2  B 4     e = B 