A 400 mm long square rod whose height and width are 20 mm by 20 mm

A 400 mm long square rod whose height and width are 20 mm by 20 mm made of isotopic
homogenious material was observed to increase in length by 600 um and to decrease by 7 um
when subjected to a 20 KN axial load. Find Modulus of Elasticity, E and Poisson\'s ratio of this
material. A 400 mm long square rod whose height and width are 20 mm by 20 mm made of
isotopic homogenious material was observed to increase in length by 600 um and to decrease by
7 um when subjected to a 20 KN axial load. Find Modulus of Elasticity, E and Poisson\'s ratio of
this material.


Solution
stress applied = axial load/cross-section area => p = (20*10^3)/(20*20) = 50 N/mm^2 As per
Hook\'s law, stress = E *strain => 50 = E *[(600*10^-3)/400] => E = 3.33 *10^4 N/mm^2
Poisson\'s ratio, u = -lateral strain/longitudinal strain => u = -[(-7*10^-3)/20]/[(600*10^-3)/400]
=> u = 0.233