取ABCD为受力平衡对象,绘受力图(如图)
求支反力过程,均布载荷q可用集中载荷P代替,
P =q.AB =(20KN/m)(0.8m)=16KN, P作用点E在AB段中点
ΣMB =0 ,P.EB +M +Rc.BC -F.BD =0
(16KN)(0.4m) +16KNm +Rc(0.8m) -(20KN)(1.6m)=0 ,算得Rc=12KN(↑)
ΣFy =0 ,RBy +Rcy -P -F =0,
RBy +12KN -16KN -20KN =0 ,算得RBy =24KN(↑)
ΣFx =0, RBx =0