Civil Engineering PE Steel Structure Design Methods 4 — Questions and Answers
Question 1: In a steel connection, what is 'block shear failure'?
- Combined shear rupture on one plane and tension rupture on a perpendicular plane (Correct answer)
- Bearing failure of the bolt hole
- Weld throat shear failure
- Prying action failure in a bolted T-stub
Correct answer: Combined shear rupture on one plane and tension rupture on a perpendicular plane
Block shear is a limit state where a block of material tears out by shear along one plane and tension along a perpendicular plane simultaneously.
Question 2: A fillet weld with a leg size of 3/8 in has an effective throat of approximately:
- 0.265 in (0.707 × 3/8) (Correct answer)
- 0.375 in (equal to leg size)
- 0.188 in (0.5 × 3/8)
- 0.530 in (2 × 0.707 × 3/8)
Correct answer: 0.265 in (0.707 × 3/8)
The effective throat of a fillet weld is 0.707 times the leg size: 0.707 × 0.375 = 0.265 in.
Question 3: The nominal shear strength of an ASTM A325 bolt in single shear (threads excluded from shear plane) with Ab = 0.601 in² is:
- Rn = 0.563 × 120 ksi × 0.601 = 40.6 kips (Correct answer)
- Rn = 0.450 × 120 ksi × 0.601 = 32.5 kips
- Rn = 0.75 × 92 ksi × 0.601 = 41.5 kips
- Rn = 1.0 × 92 ksi × 0.601 = 55.3 kips
Correct answer: Rn = 0.563 × 120 ksi × 0.601 = 40.6 kips
AISC Table J3.2 gives Fnv = 0.563Fub = 0.563 × 120 ksi = 67.6 ksi (threads excluded); Rn = 67.6 × 0.601 ≈ 40.6 kips.
Question 4: Which connection type develops the full moment capacity of the beam framing into a column?
- FR (Fully Restrained) moment connection (Correct answer)
- PR (Partially Restrained) connection
- Simple shear tab connection
- Single-plate shear connection
Correct answer: FR (Fully Restrained) moment connection
FR connections are classified as rigid and are designed to transfer the full beam moment to the column with negligible rotation.
Question 5: In designing a high-strength bolted slip-critical connection, the design slip resistance per bolt depends on:
- Class of faying surface, number of slip planes, and minimum bolt pretension (Correct answer)
- Bolt diameter and grade only
- Weld size and electrode classification
- Bearing strength of the connected material
Correct answer: Class of faying surface, number of slip planes, and minimum bolt pretension
Slip resistance = μ × Du × hf × Tb × ns, where μ is the mean slip coefficient for the surface class, Tb is pretension, and ns is the number of slip planes.
Question 6: What is the minimum edge distance for a 3/4-in bolt in a standard hole per AISC Table J3.4?
- 1 in (Correct answer)
- 1.25 in
- 0.875 in
- 1.5 in
Correct answer: 1 in
AISC Table J3.4 specifies a minimum edge distance of 1 in for a 3/4-in bolt in a standard hole at a sheared edge.
Question 7: A welded connection uses E70XX electrodes. The nominal tensile strength of the weld metal Fexx is:
- 70 ksi (Correct answer)
- 60 ksi
- 90 ksi
- 50 ksi
Correct answer: 70 ksi
The designation E70XX means the electrode has a minimum tensile strength of 70 ksi.
Civil Engineering PE Steel Structure Design Methods 4
In a steel connection, what is 'block shear failure'?