Question

A steel bar of $10\times 50mm$ is cantilevered with two $M12$ bolts (P and Q) to support a static load of $4kN$ as shown in the figure.

The primary and secondary shear loads on bolt $P$, respectively, are

• A. $20kN,0kN$
• B. $0kN,20kN$
• C. $20kN,2kN$
• D. $2kN,20kN$

Answer 1

The correct option is D $2kN,20kN$


$\Rightarrow$ Primary shear load due to $P_1$
$P_p=\frac{P_1}{n}=\frac{4}{2}=2kN$
$\Rightarrow$ Now for secondary shear load effect of $P$ and $P_2$
$TM=P\times e=8\times {10}^{6}N-mm$
$P{s}_1{r}_1+P{s}_2{r}_2=P\times e$
$\frac{P{s}_1}{r_1}[r_1^2+r_1^2]=P\times e$
$P{s}_1=P{s}_2$
$r_1=r_2$
$\frac{P{s}_1}{200}[2\times (200{)}^2]=8\times {10}^6$
$P{s}_1=P{s}_2=20,000N=20kN$