解:(1)M~PR (1-coso), M()=R sin o 2 B截面处水平位移 PR Bh Mg)M°(o)Rd=2EI E P/2( ) 解： 截面处水平位移 ( ) ( ) ( cos ) , ( ) sin ( ) ( ) 1 2 1 2 2 0 0 0 2 3 M PR M R B M M E I R PR E I BH         = − =   =  d = → P / 2 P0 = 1  