Calculate the Poissons Ratio:

In separate experiments, Young's Modulus and Rigidity Modulus of a material have been determined as 120 GPa and 50 GPa respectively. Calculate the Poisson's Ratio and Bulk Modulus of the material.

Solution

Here, Young's Modulus, E = 120 GPa.

Let Poisson's ratio be v.

Rigidity Modulus, G = E/2 (1 + v) = 50 GPa

(1 + v) = E/2G = 120/(2 × 50) = 1.2

∴          Poisson's Ratio, v = 1.2 - 1 = 0.2

Bulk Modulus,   K = E/3 (1 - 2ν)

= 120/ 3(1 - 2 × 0.2)

= 66.667 GPa.