Poisson's ratio

When you strain a material along one axis, you often see corresponding strain perpendicular to the load direction. A material under tension gets thinner, for example. The ratio of these two strains is defined as Poisson's ratio. Most materials are between 0.25-0.35 with some exceptions. Isotropic materials allow us to relate young's modulus and shear modulus through Poisson's ratio.

[@fatwafirdaus]

Thanks for your video. I understand how the Poisson's ratio for an incompressible material is 0.5, but is there any derivation why the Poisson's ratio for an isotropic material should be 0.25?

[@omerercan6579]

I am curious of the derivation as well

[@aasiqkumar732]

Man, i have a doubt, what is the poisson ratio value for rigid body. Some say zero and some says undefined. Which ine is correct. Thank you

[@TaylorSparks]

If there is no elongation or constriction then the denominator would have a 0 and dividing by zero would give you undefined I suppose

[@aasiqkumar732]

@@TaylorSparks means undefined is the answer