ASCE Structural Engineering and Materials 2 — Questions and Answers
Question 1: What is the theoretical effective length factor K for a column with both ends fixed against rotation and translation?
- 0.5 (Correct answer)
- 0.7
- 1.0
- 2.0
Correct answer: 0.5
A fixed-fixed column buckles with inflection points at quarter-lengths, giving a theoretical K of 0.5.
Question 2: What is the maximum bending moment in a simply supported beam of span L carrying a uniform load w?
- wL²/12
- wL²/8 (Correct answer)
- wL²/2
- wL²/4
Correct answer: wL²/8
For a simply supported beam under uniform load, the midspan moment is wL²/8.
Question 3: Under ACI 318, what strength reduction factor (φ) applies to tension-controlled flexural sections?
- 0.65
- 0.75
- 0.90 (Correct answer)
- 0.85
Correct answer: 0.90
ACI 318 assigns φ = 0.90 to tension-controlled sections because they fail in a ductile way.
Question 4: What is the approximate modulus of elasticity of structural steel?
- 3,600 ksi
- 10,000 ksi
- 45,000 ksi
- 29,000 ksi (Correct answer)
Correct answer: 29,000 ksi
Structural steel has E ≈ 29,000 ksi (200 GPa), regardless of grade.
Question 5: Per ACI 318, the modulus of elasticity for normal-weight concrete (psi) is approximated as:
- 57,000√f'c (Correct answer)
- 4,700√f'c
- 33√f'c
- 29,000f'c
Correct answer: 57,000√f'c
ACI gives Ec = 57,000√f'c in psi for normal-weight concrete.
Question 6: What is the typical Poisson's ratio for structural steel?
- 0.15
- 0.20
- 0.30 (Correct answer)
- 0.50
Correct answer: 0.30
Steel's Poisson's ratio is about 0.3; concrete's is about 0.15 to 0.20.
Question 7: What is the maximum deflection of a cantilever of length L with a point load P at its free end?
- PL³/48EI
- PL³/3EI (Correct answer)
- PL³/8EI
- 5PL⁴/384EI
Correct answer: PL³/3EI
The tip deflection of a cantilever with an end point load is PL³/3EI.
ASCE Structural Engineering and Materials 2
What is the theoretical effective length factor K for a column with both ends fixed against rotation and translation?