Answer to Question #261567 in Mechanical Engineering for Deepak

Question

In a triple riveted butt joint with two equal cover strips, having zigzag

arrangement of riveting the thickness of the plate 10 mm. Consider allowable

tensile, crushing and shear stress are 100 MPa, 150 MPa and 80 MPa

respectively. Calculate: - (i) diameter of rivet and (ii) pitch of rivet joint.

Answer 1

diameter of rivet $d = 6 \sqrt t = 6\sqrt10= 18.97 \approx20$ mm

pitch of rivet joint.

The shear strength of one rivet in double shear 

$p_{s1}= 1.75\times \frac{\pi}{4}d^2\times \tau_s$

The crushing strength of one rivet  

$P_{c1}=td\sigma_c$

The rivet is weaker in shearing. Equating tearing strength of plate with a shearing strength of 3 rivets in a pitch length,

$(p-d) t \sigma_t= 3\times 1.75\times \frac{\pi}{4}d^2\times \tau_s$

$p=\frac{3\times 1.75\times \frac{\pi}{4}20^2\times 80}{10\times150}+20=107.96mm$