Question

A prismatic bar of square cross-section having dimensions $800mm\times 40\times mm\times 40mm$ is subjected to a tensile stress of $120MPa$ in longitudinal axis and a compressive stress of $60MPa$ along the lateral axes. The percentage change in volume of bar is (Take $E=2\times {10}^{5}MPa;\mu =0.28$).

• A. 0

Answer 1

The correct option is A 0


${\epsilon }_{\vee }=\frac{({\sigma }_x+{\sigma }_y+{\sigma }_z)(1-2\mu )}{E}$

$\because {\sigma }_x+{\sigma }_y+{\sigma }_z=120-60-60=0$

$\therefore \Delta V={\epsilon }_{\vee }.V=0$

$\therefore$ No volume change is observed at all.