Question

An angle section ISA 80 x 80 x 10 mm is used as a tension member and is connected to gusset plate by two 16 mm diameter bolts on each of the both legs. The pitch of bolts in each leg is 60 mm. However the bolts on two legs are staggered by 30 mm. By assuming permissible tensile stress of 150 N/mm${}^2$, the allowable tension is _______.

Answer 1

Dia of bolt hole = 16+2 = 18 mm

Net section along 1-1
$=\left(\right(80+80-10)-18)\times 10=1320m{m}^2$

Net section along 1-3-4-2
$=(150-18\times 2+\frac{(30{)}^2}{4\times 80})\times 10=1168.125m{m}^2$

$\therefore \text{Allowable tension},F=\frac{150\times 1168.125}{1000}kN=175.218kN\simeq 175kN\left(say\right)$