What is the normal stress on a bar of square cross- section with
| What is the normal stress on a bar of square cross- section with side ‘b’ on which load P is applied at an angle of 30 from the horizontal?
A. <span class="math-tex">\(\frac{{\sqrt {3P} }}{{2{b^2}}}\)</span>
B. <span class="math-tex">\(\frac{{\sqrt {3P} }}{{4{b^2}}}\)</span>
C. <span class="math-tex">\(\frac{{\sqrt 3 P}}{{2{b^2}}}\)</span>
D. <span class="math-tex">\(\frac{{\sqrt 3 P}}{{4{b^2}}}\)</span>
Please scroll down to see the correct answer and solution guide.
Right Answer is: C
SOLUTION
Concept:
The normal stress on a section \(\sigma = \frac{{Norma\;force}}{{Projected\;cross - section\;area}}\)
For square section Projected cross-section area = b2
Calculation:
The component of the applied force in horizontal direction = P cos 30° = \(\frac{\sqrt{3}}{2}\)P
and the cross-section area of square = b2
thus, normal stress on the bar = \(\frac{\sqrt{3}P}{2b^2}\)
