Question

A circular shaft is subjected to a bending moment $M_b$ and a twisting moment $M_t$ . What is the ratio of maximum shear stress and the maximum bending stress ?

• A. $\frac{2M_t}{M_b}$
• B. $\frac{M_t}{M_b}$
• C. $\frac{M_t}{2M_b}$
  
• D. $\frac{1.5M_t}{M_b}$

Answer 1

The correct option is C $\frac{M_t}{2M_b}$


The ratio of maximum torsional shear stress to maximum bending stress is given by

$\frac{{\tau }_m}{f_m}=\frac{16T/\pi d^3}{32M/\pi d^3}=\frac{M_t}{2M_b}$

$(UseT=M_T;M=M_b)$