Poisson's ratio

American  

Or Poisson ratio

noun

Physics.

1. the ratio, in an elastic body under longitudinal stress, of the transverse strain to the longitudinal strain.

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Poisson's ratio British  

noun

1.  μ.   ν.  a measure of the elastic properties of a material expressed as the ratio of the fractional contraction in breadth to the fractional increase in length when the material is stretched

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Etymology

Origin of Poisson's ratio

First recorded in 1925–30; see origin at Poisson distribution

Example Sentences

See Examples For:

Poisson's ratio

The breakthrough centered on a property called Poisson's ratio, which describes how materials change shape when stretched.

From Science Daily ● May 13, 2026

By pairing in-situ sound velocity measurements with advanced molecular dynamics simulations, the team detected a dramatic loss of shear wave speed and a sharp increase in Poisson's ratio.

From Science Daily ● Dec. 10, 2025

Another way of expressing Poisson's ratio is that it describes the relationship between shape and volume when one of these changes.

From Science Daily ● Jun. 4, 2024

Most materials have a positive Poisson's ratio, which means squeezing them in one direction will make them wider and/or thicker in other directions.

From Science Daily ● Jun. 4, 2024

The amount of this contraction is σT/E, where σ is a certain number called Poisson’s ratio, because its importance was at first noted by S.D.

From Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" by Various