To evaluate the shear strength of a rivet material, a tensile test was done with a 20 mm diameter rivet in a configuration as shown in figure. At 8.8 kN, the rivet shears off. The ultimate shear strength of the rivet material is?

Explanation:

Shearing of the rivets: The plates which are connected by the rivets exert tensile stress on

the rivets, and if the rivets are unable to resist the stress, they are sheared off.

The resistance offered by a rivet to be sheared off is known as shearing resistance or shearing strength or shearing value of the rivet

d = Diameter of the rivet hole, τ = Safe permissible shear stress for the rivet material, and n = Number of rivets per pitch length

Shearing resistance or pull required to shear off the rivet per pitch length:

\({P_s} = n \times \frac{\pi }{4}{d^2} \times \tau \;\;\;\;\;\;\left\{ {{\rm{Single\;Shear}}} \right\}\)

\({P_s} = 2n \times \frac{\pi }{4}{d^2} \times \tau \;\;\;\;\;\;\left\{ {{\rm{Double\;Shear}}} \right\}\)

So, the strength equation for the rivet in the double-riveted joints is given by:

\({\tau_s} = \frac{P_s}{2\times\frac{\pi}{4}\times d^2}=\frac{8.8\times 10^3}{2\times\frac{\pi}{4}\times(20)^2}=14 ~\rm{N/mm^2}=14 ~MPa\)