Poisson's ratio
parameter of elastic materials: ratio of transverse strain to axial strain
AI overview
Poisson's ratio measures how much a material squeezes or expands sideways when you stretch or compress it along one direction—for example, how much a rubber band gets thinner when you pull it longer. This ratio helps engineers and scientists predict how materials will behave under stress, which is important for designing safe structures and products.
AI-generated from the Wikipedia summary — may contain errors.
Article
Poisson's ratio of a material defines the ratio of transverse strain (x direction) to the axial strain (y direction). In materials science and solid mechanics, Poisson's ratio (symbol: ν (nu)) is a measure of the Poisson effect, the deformation (expansion or contraction) of a material in directions perpendicular to the specific direction of loading. The value of Poisson's ratio is the negative of the ratio of transverse strain to axial strain. For small values of these changes, ν is the amount of transversal elongation divided by the amount of axial compression.
Most materials have Poisson's ratio values ranging between 0.0 and 0.5. For soft materials, such as rubber, where the bulk modulus is much higher than the shear modulus, Poisson's ratio is near 0.5. For open-cell polymer foams, Poisson's ratio is near zero, since the cells tend to collapse in compression. Many typical solids have Poisson's ratios in the range of 0.2 to 0.3.