The difference between two principal stresses is \(120 \text{ MPa}\), when a circular shaft is subjected to an axial force and shear force. What is the factor of safety based on maximum shear stress theory if elastic limit of the bar is \(300 \text{ MPa}\)?
Show Hint
Under Tresca's maximum shear stress theory, for any two-dimensional stress case where the principal stresses have opposite signs or are standard planar outputs, the design relation simplifies directly to:
\[
\text{F.O.S.} = \frac{\sigma_{\text{yield}}}{\sigma_1 - \sigma_2}
\]
This avoids calculating intermediate shear values.