Question

A circular shaft is subjected to a twisting moment T and bending moment M. The ratio of Maximum bending stress to Maximum shear stress is given by:

• A. 2M/T
• B. M/T
• C. 2T/M
• D. M/2T

Answer 1

Answer:

C. 2T/M

Maximum bending stress, $\sigma_{b} =\frac{My}{I} = \frac{M}{Z} =\frac{32M}{\pi d ^ 3}$ ; Maximum shear stress, $\tau= \frac {16T}{pi d ^ 3} \Rightarrow \frac{\sigma_b}{\tau} =\frac{2M}{ T}$