What is the design tensile strength of the plate 130 mm × 12 mm with holes for 16 mm diameter bolts by considering yielding of gross section ? (Take fy = 250 N/mm² and γm0 = 1·1)
- A332·986 kN
- B340·570 kN
- C354·545 kNCorrect
- D380·765 kN
Solution
Concept
Design strength governed by gross-section yielding
Formula
Tdg = Ag fy / γm0
Step-by-step solution
1. Ag = 130 × 12 = 1560 mm² (holes are ignored for yielding of the gross section). 2. Tdg = 1560 × 250 / 1.1 = 354 545 N = 354.545 kN.
Explanation
Yielding of the gross section is checked on the full area because yielding spreads over the entire length of the member, so bolt holes do not reduce the area.
Why the other options are wrong
Only 354.545 kN equals Ag fy / γm0 = 1560 × 250 / 1.1. The other values are not obtained from the gross area.
Shortcut
Gross area × fy / 1.10.
Common mistake
Deducting the bolt hole.
Correct answer: C) 354·545 kN