Solution
cosθ=a500=45cosθ=a500=45
a=400 mma=400 mm
secθ=b400=54secθ=b400=54
b=500 mmb=500 mm
ΣM1=0ΣM1=0
(a+b)R2=(500+400+100)450(a+b)R2=(500+400+100)450
900R2=(1000)450900R2=(1000)450
R2=500 kNR2=500 kN
cosθ=c200=45cosθ=c200=45
c=160 mmc=160 mm
M3=500(200)−450(c+100)M3=500(200)−450(c+100)
M3=100,000−450(160+100)M3=100,000−450(160+100)
M3=−17,000 kN⋅mmM3=−17,000 kN⋅mm
M3=17,000 k N⋅ mm clockwiseM3=17,000 k N⋅ mm clockwise
Fa=450sinθ=450(3/5)Fa=450sinθ=450(3/5)
Fa=270 kNFa=270 kN
σa=PA=270(1000)200(200)σa=PA=270(1000)200(200)
σa=6.75 MP aσa=6.75 MPa
σf=6Mbd2=6(17,000)(1000)200(2002)σf=6Mbd2=6(17,000)(1000)200(2002)
σf=12.75 MPa σf=12.75 MPa
σA=−σa+σf=−6.75+12.75σA=−σa+ σf=−6.75+12.75
σA=6 MPaσA=6 MPa answer
σB=−σa−σf=−6.75+12.75σB=−σa−σf=−6.75+12.75
σB=−19.5 MPaσB=−19.5 MPa answer
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