Question

The maximum tensile stress at the section X-X shown in the figure below is

• A. $\frac{8P}{bd}$
• B. $\frac{6P}{bd}$
• C. $\frac{4P}{bd}$
• D. $\frac{2P}{bd}$

Answer 1

The correct option is A $\frac{8P}{bd}$

a)
eccentricity at

X - X = $\frac{d}{4}$

Maximum tensile stress,

s = $\frac{P}{A}+\frac{My}{I}$ = $\frac{P}{b.\frac{d}{2}}+\frac{P.\left(\frac{d}{4}\right).\left(\frac{d}{4}\right)}{\frac{b(\frac{d}{2}{)}^3}{12}}$

= $\frac{2P}{bd}+\frac{6P}{bd}=\frac{8P}{bd}$