Question

A mild steel bar of uniform cross-section A and length L is subjected to an axial load W. The strain energy stored in the bar would be

• A. $\frac{WL}{2AE}$
• B. $\frac{W^{2}L}{4AE}$
• C. $\frac{WL}{4AE}$
• D. $\frac{W^{2}L}{2AE}$

Answer 1

The correct option is D $\frac{W^{2}L}{2AE}$

Deformation in the bar, $\Delta =\frac{WL}{AE}$

$Strainenergy=\frac{1}{2}W\Delta =\frac{W^{2}L}{2AE}$