XZ 面 Z FBVF ∑MA(F)=0 X FAHI FBH F=0 T d282.5 ×1284.8N·mm 2 2 =181481N·mmExz面: x z MT FAH FBH FBV FAV FT Fr ( ) 0 M F A = 0 2 T t d M F − = 282.5 1284.8 2 2 T t d M F N mm = =   =  181481N mm