Poisson's ratio
A measure of transverse deformation under axial loading.
Poisson's ratio (symbol: ν) is a measure of the Poisson effect, the deformation of a material in directions perpendicular to the direction of loading. It is defined as the negative of the ratio of transverse strain to axial strain. Most materials have Poisson's ratio values between 0.0 and 0.5, with soft materials like rubber near 0.5 and open-cell polymer foams near zero.
- field
- Materials science, solid mechanics
- known_for
- Poisson's ratio, the Poisson effect
- named_after
- Siméon Poisson, French mathematician and physicist
Lore & Background
Poisson's ratio quantifies the Poisson effect, where a material expands perpendicular to compression or contracts perpendicular to stretching. For small strains, it is the negative ratio of transverse to axial strain. The ratio is named after the French mathematician and physicist Siméon Poisson.
Reader's Guide
Poisson's ratio is a fundamental parameter in materials science and solid mechanics, describing how a material deforms laterally when stretched or compressed. Its value typically ranges from 0.0 to 0.5 for most materials, with rubber near 0.5 and cork near zero. For stable, isotropic, linear elastic materials, the ratio must lie between -1.0 and +0.5. Some materials, called auxetic, exhibit negative Poisson's ratio, becoming thicker when stretched. The ratio is crucial for understanding material behavior under load, influencing design in engineering and physics.
Did You Know?
- Poisson's ratio is the negative of the ratio of transverse strain to axial strain.
- Most materials have Poisson's ratio values between 0.0 and 0.5.
- Rubber has a Poisson ratio of nearly 0.5.
- Auxetic materials can exhibit negative Poisson's ratio.
More in Classical And Fluid Mechanics 1-19
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