Question

A circular shaft of diameter 120 mm is welded to a rigid plate by a fillet weld of size 6 mm. If a torque of 8 kN-m is applied to the shaft, then the maximum stress induced in the weld is_____.

Answer 1

$\text{Strength of weld per mm length}=0.7\times 6\times \sigma$
$=4.2\sigma$
$\text{Weld length}=\pi d$
$=\pi \left(120\right)mm$
$\therefore \text{Maximum twisting moment,}T=\left(4.2\sigma \right)120\pi \left(\frac{120}{2}\right)$
$\Rightarrow 8\times {10}^6=\left(4.2\sigma \right)120\pi \left(60\right)$
$\Rightarrow \sigma =84.21\simeq 84N/m{m}^2$