计算支反力时,均布荷载可用等效的集中荷载P代替,
P的大小 =q(2m) =(2KN/m)(2m) =4KN
P的作用点在均布段中点,即:
P对B点取矩的力臂=1m, P对A点取矩的力臂=6m+1m =7m
ΣMA =0, FBy.6m -P.7m -F.4m -M =0
FBy.6m -(4KN)(7m) -(3KN)(4m) -4KN.m =0
FBy =22/3KN(向上)
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ΣMB =0, -FAy.6m -P.1m +F.2m -M =0
-FAy.6m -(4KN)(1m) +(3KN)(2m) -4KN.m =0
FAy = -(1/3)KN(向下)
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ΣFx =0, FAx =0
以A点为支座。B点给予一个竖向力,弯矩平衡就可以算出。Fb=(5x1-5x2)=-5/3