Question

Two equal angles ISA 100 mm x 100 mm of thickness 10 mm are placed back-to-back and connected to the either side of a gusset plate through a single row of 16 mm diameter rivets in double shear. The effective area of the connected and unconnected legs of each of these angles are 775 mm${}^2$ and 950 mm${}^2$, respectively. If these angles are not tack riveted, the net effective area of this pair of angles is______.

• A. $3650m{m}^2$
• B. $2899m{m}^2$
• C. $3076m{m}^2$
• D. $3450m{m}^2$

Answer 1

The correct option is B $2899m{m}^2$

If angles are not tacked, they will behave as single angle connected to gusset plate.
So, effective area of pair of angles
= 2 x Net effective area of each angle

Area of connected leg,
$A_1=775m{m}^2$

Area of unconnected leg,
$A_2=950m{m}^2$

Net effective area
$A_{net}=A_1+k{A}_2$

$where,K=\frac{3A_1}{3A_1+A_2}=\frac{3\times 775}{3\times 775+950}$

$=0.71$

$A_{net}=A_1+k{A}_2$
$=775+0.71\times 950$
$=1449.43m{m}^2$

$\therefore$ Effective area of pair of angles
$=2\times 1449.43=2898.86$
$=2899m{m}^2$