Draft

5.2Trusses 97

NodeA:ClearlyAHis undercompression,andABundertension.

(+ 6 ) Fy= 0; ) FAH

y

58 = 0

FAH=

l

ly

(FAH

y

)

ly= 32 l=

p

32

2

+ 24

2

= 40

) FAH=

40

32

(58)= 72: 5 Compression

(+-) Fx= 0; ) FAH

x

+FAB= 0

FAB=

lx

ly

(FAH

y

) =

24

32

(58)= 43: 5 Tension

NodeB:

(+-) Fx= 0; ) FBC = 43 : 5 Tension

(+ 6 ) Fy= 0; ) FBH = 20 Tension

NodeH:

(+-) Fx= 0; ) FAH

x

FHC

x

FHG

x

= 0

43 : 5 

p^24

242 +32^2

(FHC)

p^24

242 +10^2

(FHG) = 0 (I)

(+ 6 ) Fy= 0; ) FAH

y

+FHC

y

 12 FHG

y

20 = 0

58 +

32

p

242 +32^2

(FHC) 12

10

p

242 +10^2

(FHG)20 = 0 (II)

SolvingforI andII we obtain

FHC = 7 : 5 Tension

FHG = 52 Compression