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

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Example Sentences

See Examples For:

Poisson's ratio

Even though the inner core is solid, it behaves like a softened metal, slowing seismic shear waves and displaying a Poisson's ratio more similar to butter than to steel.

From Science Daily ● Dec. 10, 2025

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

Auxetics have a negative value of Poisson's ratio and do exactly the reverse.

From Science Daily ● Jun. 4, 2024

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

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

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