Question

A mild steel structural section is an unsymmetrical I-section, with the greater width at the top and the smaller width at the bottom. The overall depth of the beam is 300 mm, and the flange stresses at the top and the bottom of the beam are $150N/m{m}^2$ and $50N/m{m}^2$, respectively. What is the height of the neutral axis of the beam from its bottom?

• A. 125 mm
• B. 100 mm
• C. 75 mm
• D. 50 mm

Answer 1

The correct option is C 75 mm


From stress diagram,

$\frac{50}{x}=\frac{150}{300-x}$

$\Rightarrow 15000-50x=150x$

$\Rightarrow x=75mm$