Question

A section of a solid circular shaft with diameter D is subjected to bending moment M and torque T. The expression for maximum principal stress at the section is

• A. $\frac{2M+T}{\pi D^3}$
• B. $\frac{16\pi }{D^3}(M+\sqrt{M^2+T^2})$
• C. $\frac{16\pi }{D^3}\left(\sqrt{M^2+T^2}\right)$
• D. $\frac{16}{\pi D^3}(M+\sqrt{M^2+T^2})$

Answer 1

The correct option is D $\frac{16}{\pi D^3}(M+\sqrt{M^2+T^2})$

Principal stresses,

${\sigma }_1/{\sigma }_2=\frac{16}{\pi D^3}[M\pm \sqrt{M^2+T^2}]$

Maximum principal stress is obtained by chosing '+' sign and minimum principal stress is obtained by '-' sign.