Question

A group of rivets at a joint is subjected to inplane torsion moment M. The rivets have finished areas of cross - section $A_i$ (i = 1, 2...., n ) and distances $r_1$ ( i = 1, 2 ..., n) from CG of the rivet group shown in figure. The shear force developed in $i^{th}$ rivet is proportional to

• A. distance from CG of group, $r_i$ only
• B. polar moment of inertia of group of areas $A_i$
• C. both $A_i$ and $r_i$
• D. area of cross - section, $A_i$ only

Answer 1

The correct option is B polar moment of inertia of group of areas $A_i$

$F_{ti}=$ Torsional shear force in $i^{th}$ rivet

$F_{ti}=\frac{M{r}_i{A}_i}{J}$

J $\to$ Polar moment of inertia of the rivet group

$J=\sum A_i{r}_i^2$