1a22a C c·a EⅠ(23 BEN EI( 2 2EI 由O1X1+△1p=0得X1=8 XB=0.D=82(4) 8 X=O Y 11 g 2 84()M=38(逆时针)( ) ( ) ( )   11 2 2 3 1 3 4 11 1 1 1 2 1 2 2 3 4 3 1 2 2 0 3 8 0 3 8 0 11 8 8 =  +        = = −        = − + = =  = =  = =  = EI a a a a a EI EI qa a qa EI X X qa X Y qa X Y qa M qa P P B B A A A  由  得 逆时针 , ,