Answer:
hello a diagram attached to your question is missing attached below is the missing diagram
The three suspender bars AB, CD, and EF are made of A-36 steel and have equal cross-sectional areas of 500 mm2. Determine the average normal stress in each bar if the rigid beam is subjected to a force of P = 70kN , let d = 2.4 m , L = 4m
Answer :
Stress = force / area
for Bar 1 = (40.03 * 1000) / 500 = 80.06 MPa
Bar 2 = ( 23.33 * 1000 ) / 500 = 46.66 MPa
for Bar 3 = ( 5.33 * 1000 ) / 500 = 10.66 MPa
Explanation:
Given data:
Type of steel = A-36
cross-sectional area = 500 mm^2
Calculate the average normal stress in each bar
we have to make some assumptions
assume forces in AB, CD, EF to be p1,p2,p3 respectively
∑ Fy = 0 ; p1 + p2 + p3 = 70kN ---------- ( 1 )
∑ Mc = 0 ; P1 * d - p * d/2 - p3 * d = 0
where d = 2.4 hence ; p1 - p3 = 35 -------- ( 2 )
Take ; Tan∅
Tan∅ = MN / 2d = OP/d
i.e. s1 - 2s2 - s3 = 0
[tex]\frac{P1L}{AE} - \frac{2P2}{AE} + \frac{P3L}{AE} = 0[/tex]
L , E and A are the same hence
P1 - 2p2 + p3 = 0 ----- ( 3 )
Next resolve the following equations
p1 = 40.03 kN, p2 = 23.33 kN, p3 = 5.33 kN
Stress = force / area
for Bar 1 = (40.03 * 1000) / 500 = 80.06 MPa
Bar 2 = ( 23.33 * 1000 ) / 500 = 46.66 MPa
for Bar 3 = ( 5.33 * 1000 ) / 500 = 10.66 MPa
