Question

Two plates of 7 mm thick are connected by a triple riveted lap joint Zig-Zag pattern. The diameter of rivet is 18mm and pitch of rivet is 80 mm. What is the magnitude and mode of failure of joint ?
[Assume, ${\sigma }_t=90$ MPa, $\tau$ 40 MPa and ${\sigma }_c$ = 120 MPa].

Answer 1

t = 7 mm, P = 80 mm d = 18 mm

${\sigma }_t$ = 90 MPa,

${\sigma }_s=\tau$ = 40 MPa, ${\sigma }_c$ = 120 MPa
$F_t=(p-d)t\times {\sigma }_t=(80-180)\times 7\times 90$

$=39.06\times {10}^{3}N\text{(Tear)}$

$F_s=\frac{\pi }{4}{d}^2{\tau }_s\times 3=\frac{\pi }{4}\times \left({18}^2\right)\times 40\times 3=30.534\times {10}^{3}N\text{(Shear)}$

$F_c=3\times {\sigma }_c\times d\times t=3\times 120\times 18\times 7=45.36\times {10}^{3}N\text{(crushing)}$

Among $F_t,F_s\text{and}{F}_c,$ the least value is of $F_s$.

$\therefore \text{Fail by shear with load 30.534 kN}$