Civil Engineering PE Steel Structure Design Methods 2

Question 1

In LRFD design, which load combination governs for a steel beam subjected to dead load D = 20 kips and live load L = 40 kips?

Accepted Answer

1.2D + 1.6L = 88 kips

Answer

1.4D = 28 kips

Answer

1.2D + 1.0L = 64 kips

Answer

1.0D + 1.0L = 60 kips

Question 2

What does the resistance factor φ = 0.90 represent in LRFD steel design for tension yielding?

Accepted Answer

A safety margin accounting for variability in material strength and fabrication

Answer

The ratio of live load to dead load

Answer

A reduction for long-term creep effects

Answer

The inverse of the factor of safety used in ASD

Question 3

A W-shape beam has a plastic section modulus Zx = 120 in³ and Fy = 50 ksi. What is the plastic moment Mp?

Accepted Answer

6,000 kip-in

Answer

5,400 kip-in

Answer

4,800 kip-in

Answer

7,200 kip-in

Question 4

In ASD for steel, the allowable bending stress Fb for a compact section in a braced frame with Fy = 36 ksi is typically:

Accepted Answer

0.66Fy = 23.76 ksi

Answer

0.60Fy = 21.6 ksi

Answer

0.75Fy = 27 ksi

Answer

0.50Fy = 18 ksi

Question 5

Which steel design method explicitly accounts for the probability of failure through reliability index β?

Accepted Answer

LRFD

Answer

ASD

Answer

Both ASD and LRFD equally

Answer

Allowable stress design only for fatigue

Question 6

For a tension member, AISC LRFD requires checking two limit states. Which pair is correct?

Accepted Answer

Yielding on gross area and fracture on net area

Answer

Yielding on net area and fracture on gross area

Answer

Bearing and shear rupture only

Answer

Block shear and bearing only

Question 7

In steel design, the shear factor of safety in ASD is typically set at approximately:

Accepted Answer

1.67 (Fv = 0.40Fy)

Answer

2.0 (Fv = 0.50Fy)

Answer

1.50 (Fv = 0.45Fy)

Answer

2.5 (Fv = 0.33Fy)