Question

A brake band is attached to the hinge by means of a riveted lap joint having 4 rivets. The permissible stresses for the band and rivets in shear, compression are 60 and 120 $m{m}^2$, respectively. The thickness of the plate is 3 mm. The diameter of the rivets needed for the load of 10 kN is __________mm

• A. 10 mm
• B. 9 mm
• C. 8 mm
• D. 7 mm

Answer 1

The correct option is C 8 mm

From shear consideration

$4\left[\frac{\pi }{4}{d}^2\tau \right]$ = p

$4[\frac{\pi }{4}{d}^2\times 60]=10\times {10}^3$

d = 7.28 = 8mm

From crushing consideration ,

4 dt ${\sigma }_c$ = P

4d x (3) x (120) = 10 x 10^{3}

d = 6.94 = 7 mm

shearing becomes the criterion of desing
d =8 mm.