Definition: The ratio of tensile stress to tensile strain below the proportional limit.
Related to shear modulus, G, and bulk modulus, B, as follows
ν = Poisson's Ratio
The ratio of normal stress to corresponding strain for tensile or compressive stresses below the proportional limit of the material which is the greatest stress a material is capable of sustaining without any deviation from proportionality of stress to strain (see HOOKE'S LAW). For perfectly elastic materials, it is the ratio of the change in stress to change in strain within the elastic limits. See also MODULUS OF ELASTICITY.