STEEL DESIGN [7TH EDITION]
William T. Segui and Sayed M. Soleimani
CHAPTER 1 – INTRODUCTION
1.5-1
(a) 𝐴 = 𝜋(0.550)2 /4 = 0.2376 in.2
𝑃𝑢 28,500
𝐹𝑢 = = = 120,000 psi = 120 ksi
𝐴 0.2376
Fu = 120 ksi (827.4 MPa)
2.300−2.030
(b) 𝑒 = × 100 = 13.3%
2.030
e = 13.3%
(c) 𝐴𝑓 = 𝜋(0.430)2 /4 = 0.1452 in.2
𝐴𝑓 −𝐴𝑜 0.1452−0.2376
Change = × 100 = × 100 = −38.9%
𝐴𝑜 0.2376
Reduction = 38.9%
1.5-2
𝐴 = 𝜋(0.5)2 /4 = 0.1963 in.2
𝑃 13.5
𝑓= = = 68.77 ksi
𝐴 0.1963
Δ𝐿 4.66 × 10−3
𝜀= = = 2.33 × 10−3
𝐿 2
𝑓 68.77
𝐸= = = 29,500 ksi
𝜀 2.33 × 10−3
E = 29,500 ksi (203.4 GPa)
[1-1]
© 2026 Cengage Learning®. All Rights Reserved. May not be scanned, copied, or duplicated,
or posted to a publicly accessible website, in whole or in part.
,1.5-3
𝐴 = 𝜋(0.510)2 /4 = 0.2043 in.2
𝑃 250
For 𝑃 = 250 lb, 𝑓 = 𝐴 = 0.2043 = 1224 psi
Spreadsheet results:
(a)
(b)
(c)
E = slope = 31,600 ksi (217.9 GPa)
[1-2]
© 2026 Cengage Learning®. All Rights Reserved. May not be scanned, copied, or duplicated,
or posted to a publicly accessible website, in whole or in part.
,1.5-4
𝐴 = 𝜋(0.5)2 /4 = 0.1963 in.2
𝑓 𝑃/𝐴 𝑃 𝐿
𝐸= = = ⋅ = 1,392(4/0.1963) = 28,400 ksi
𝜀 Δ𝐿/𝐿 Δ𝐿 𝐴
E = 28,400 ksi (195.8 GPa)
1.5-5
𝐴 = 𝜋(3/8)2 /4 = 0.1104 in.2
𝑃 550
For 𝑃 = 550 lb, 𝑓 = 𝐴 = 0.1104 = 4,982 psi
Δ𝐿 350 × 10−6
𝜀= = = 175 × 10−6
𝐿 2
Spreadsheet results:
(a)
[1-3]
© 2026 Cengage Learning®. All Rights Reserved. May not be scanned, copied, or duplicated,
or posted to a publicly accessible website, in whole or in part.
, (b)
15,000
(c) 𝐸 = slope = 500×10−6 = 30,000,000 psi = 30,000 ksi
E = 30,000 ksi (206.8 GPa)
(d)
Fy ≈ 44,000 psi ≈ 44 ksi (≈ 303 MPa)
[1-4]
© 2026 Cengage Learning®. All Rights Reserved. May not be scanned, copied, or duplicated,
or posted to a publicly accessible website, in whole or in part.
William T. Segui and Sayed M. Soleimani
CHAPTER 1 – INTRODUCTION
1.5-1
(a) 𝐴 = 𝜋(0.550)2 /4 = 0.2376 in.2
𝑃𝑢 28,500
𝐹𝑢 = = = 120,000 psi = 120 ksi
𝐴 0.2376
Fu = 120 ksi (827.4 MPa)
2.300−2.030
(b) 𝑒 = × 100 = 13.3%
2.030
e = 13.3%
(c) 𝐴𝑓 = 𝜋(0.430)2 /4 = 0.1452 in.2
𝐴𝑓 −𝐴𝑜 0.1452−0.2376
Change = × 100 = × 100 = −38.9%
𝐴𝑜 0.2376
Reduction = 38.9%
1.5-2
𝐴 = 𝜋(0.5)2 /4 = 0.1963 in.2
𝑃 13.5
𝑓= = = 68.77 ksi
𝐴 0.1963
Δ𝐿 4.66 × 10−3
𝜀= = = 2.33 × 10−3
𝐿 2
𝑓 68.77
𝐸= = = 29,500 ksi
𝜀 2.33 × 10−3
E = 29,500 ksi (203.4 GPa)
[1-1]
© 2026 Cengage Learning®. All Rights Reserved. May not be scanned, copied, or duplicated,
or posted to a publicly accessible website, in whole or in part.
,1.5-3
𝐴 = 𝜋(0.510)2 /4 = 0.2043 in.2
𝑃 250
For 𝑃 = 250 lb, 𝑓 = 𝐴 = 0.2043 = 1224 psi
Spreadsheet results:
(a)
(b)
(c)
E = slope = 31,600 ksi (217.9 GPa)
[1-2]
© 2026 Cengage Learning®. All Rights Reserved. May not be scanned, copied, or duplicated,
or posted to a publicly accessible website, in whole or in part.
,1.5-4
𝐴 = 𝜋(0.5)2 /4 = 0.1963 in.2
𝑓 𝑃/𝐴 𝑃 𝐿
𝐸= = = ⋅ = 1,392(4/0.1963) = 28,400 ksi
𝜀 Δ𝐿/𝐿 Δ𝐿 𝐴
E = 28,400 ksi (195.8 GPa)
1.5-5
𝐴 = 𝜋(3/8)2 /4 = 0.1104 in.2
𝑃 550
For 𝑃 = 550 lb, 𝑓 = 𝐴 = 0.1104 = 4,982 psi
Δ𝐿 350 × 10−6
𝜀= = = 175 × 10−6
𝐿 2
Spreadsheet results:
(a)
[1-3]
© 2026 Cengage Learning®. All Rights Reserved. May not be scanned, copied, or duplicated,
or posted to a publicly accessible website, in whole or in part.
, (b)
15,000
(c) 𝐸 = slope = 500×10−6 = 30,000,000 psi = 30,000 ksi
E = 30,000 ksi (206.8 GPa)
(d)
Fy ≈ 44,000 psi ≈ 44 ksi (≈ 303 MPa)
[1-4]
© 2026 Cengage Learning®. All Rights Reserved. May not be scanned, copied, or duplicated,
or posted to a publicly accessible website, in whole or in part.