X cosa sina 0 000 X sIna cosa 00X1 0 0:000 0 cosa sina 0 00:-Sind cosa 0 0 0 0 (F}=[T]{F a F}=[7{F} 单元坐标转换矩阵[门是一正交矩阵。[T]=[7] 同理:{△}=[门]{4(b)→{△=[ 整体坐标系中的单元刚度矩阵 设:{F}=[k]{}将(a)、(b)代入{F=[k] [7{F}a=[][7]{△}0 T][]{FP=[Tk][7]{△}210 =                       @ 2 2 2 1 1 1 M Y X M Y X @ 2 2 2 1 1 1                       M Y X M Y X                     - - 0 0 0 0 0 1 0 0 0 sin cos 0 0 0 0 cos sin 0 0 0 1 0 0 0 sin cos 0 0 0 0 cos sin 0 0 0 0         T= 单元坐标转换矩阵[T]是一正交矩阵。 T [T] [T] 1 = - 同理： ▪整体坐标系中的单元刚度矩阵 @ @ @ 设： {F} = [k] {D} 将（a）、（b）代入 （a） （b） @ @ @ [T]{F} = [k ] [T]{D} @ @ @ [T] [T]{F} = [T] [k ] [T]{D} T T @ @ {F} = [T]{F} @ @ {F} [T] {F} T  = @ @ {D} = [T]{D} @ @ {D} = [ ] {D} T T @ @ @ {F} = [k ] {D}