The document outlines the principles of steel design focusing on rupture in net section area and tensile resistance calculation. It explains how to calculate effective net area (ane), shear lag factors, and net area calculation with specific formulas and conditions. Various scenarios for shear lag and net area are provided, including the effects of fastener lines on shear lag factors.

1. 5 Minutes Structure 1

2. Topic –
Steel Design 03:
Rupture in Net Section Area
5 Minutes Structure 2

3. Tensile Resistance for Rupture in Net Section Area
𝑇𝑟 = φ𝑢 ∗ 𝐴𝑛𝑒 ∗ 𝐹𝑢
φu = 0.75
Fu = Ultimate Strength
Ane = Effective Net Area = U * An
5 Minutes Structure 3

4. How to Calculate Effective Net Area Ane?
Ane = U*An
U = Shear Lag Factor
If Material is stresses uniformly, U value will be 1.
Shear lag occurs due to non-uniform stress.
5 Minutes Structure 4

5. How to calculate shear lag? (CISC Handbook)
Clause 12.3.3
 WWF, W, M, S flange widths not less than two third
depths and structural tees cut from these shape.
U= 0.9
5 Minutes Structure 5

6.  Angles Connected by only one legs
Four or more transverse line of fasteners – U = 0.8
Fewer than four transverse line of fasteners- U= 0.6
 All other structural shapes
Three or more line of fasteners U= 0.85
Two transverse line of fastener U = 0.75
5 Minutes Structure 6

7. Net Area Calculation, An
An = Wn *t
Here, Wn = Net Width = W – (dh + 2 or 4)*n
dh = Depth of Holes
If the holes are punched, then take 4mm
If the holes are drilled, then take 2mm.
t = Thickness of Plate
n = number of holes along the path
5 Minutes Structure 7

8. 5 Minutes Structure 8

9. Staggered Holes
5 Minutes Structure 9

10. Staggered Holes
An = Wn*t +
𝑆2
4𝑔
∗ 𝑡
Here, s = Pitch (Center to Center Spacing of the bolts
along the direction of applied load)
g = Gauge (Center to Center Spacing of the bolts along
the perpendicular direction of applied load)
5 Minutes Structure 10

11. Thank You
5 Minutes Structure
5 Minutes Structure 11