Question

A circular shaft of diameter 120 mm is welded to a rigid plate by a fillet weld of size 8 mm. If a torque of 12 kN- m is applied to the shaft, then the maximum stress in the weld will be ______ N/mm${}^2$.

Answer 1

$\because {\tau }_{max}=\frac{T.r}{I_P}$
$I_P=2\pi r^{3}t=\frac{\pi d^{3}t}{4}=\frac{\pi \times (120{)}^3\times (0.7\times 8)}{4}$

$=7.6\times {10}^{6}m{m}^4$

$r=\frac{d}{2}=\frac{120}{2}=60mm$

${\tau }_{max}=\frac{12\times {10}^6\times 60}{7.6\times {10}^6}=94.74N/m{m}^2$