Question

A 6 mm thick mild steel plate is connected to an 8 mm thick plate by 16 mm diameter shop rivets. What is the number of rivets required to carry an 80 kN load?
1. 2
2. 3
3. 4
4. 6

Answer 1

Correct Answer - Option 3 : 4

For shop rivets permissible stresses are

In shearing, τ_s = 100 MPa

In bearing, σ_b = 300 MPa  

The gross diameter of hole (D)

= 16 + 1.5 = 17.5

Strength of rivets in bearing = Dtσ_b

= 17.5 × 6 × 300 = 31.5 kN

Strength of rivets on single shear

\(\begin{array}{l} = \frac{{\pi {D^2}}}{4} \times {\tau _s}\\ = \frac{\pi }{4} \times {\left( {17.5} \right)^2} \times 100 \end{array}\)

= 24.05 kN

∴ Rivet valve = 24.05 kN

Hence, number of rivets required

\(= \frac{{80}}{{24.05}} = 3.33 \approx 4\)