Question

A circular rod of diameter 'd' and length '3d' is subjected to a compressive force 'F' acting at the top point as shown in the fig. The stress at point 'A' is

• A. $\frac{20F}{\pi d^2}$ (Tensile)
• B. $\frac{20F}{\pi d^2}$ (Compressive)
• C. $\frac{12F}{\pi d^2}$ (Compressive)
• D. $\frac{12F}{\pi d^2}$ (Tensile)

Answer 1

The correct option is D $\frac{12F}{\pi d^2}$ (Tensile)


There is compressive force F and constant bending moment

$F\times \frac{d}{2}$.

At point A, there is compressive stress due to load F and tensile stress due to bending moment.

$\sigma =-\frac{4F}{\pi d^2}+\frac{32M}{\pi d^2}$

$\sigma =\frac{16F}{\pi d^2}-\frac{4F}{\pi d^2}$

$\sigma =\frac{12F}{\pi d^2}$ (Tensile)