What is Poisson's ratio?
Poisson's ratio deals with how to stretch or compress the object in one direction causes to compress or stretch in the opposite direction. The ratio measures the extent of this effect in a particular substance. This may vary significantly and the ratio can even be negative, usually in human -created substances. It sounds complicated, but describes a relatively simple effect. You want to imagine it, imagine a piece of rubber like the one that is used in the rubber band. When you stretch the band, it becomes both narrower and longer. The relationship between these two changes is what is measured by Poisson's ratio.
In fact, Poisson's ratio applies in three dimensions. In the example of the rubber band, the thickness of the stretched zone is also reduced - it is only harder to see. If you want to imagine the effect in three dimensions, imagine that you take a pet in the shape of a cube and the sding of two opposite sides. The cube will obtain a contract in the direction between these two parties, but will expand in the next two directions.
In most cases, Poisson's ratio is positive, which means that the material stretches in one direction to a greater extent than it is downloaded in other directions. There are several explanations that use different scientific approaches. A simple explanation is that most materials can better withstand compression than to withstand stretching. A more complicated explanation is that the bonds between the atoms in the structure are equalized during the stretching and compressing process.
In most cases, Poisson's ratio will be between 0 and 0.5. Among the common materials, the Poisson rubber ratio has a very close ratio of 0.5, while the steel has one of 0.3 and the Cork is much closer to 0. Therefore, Corks wine is made of cork: Tovyrjí pressure from the bottle without stretching vertically and stuck in place.
It is possible to have a negative Poisson ratio. Materials showing this quality are known as auxetics. With such materials of their stretching in one directioncause to expand in other directions. It is suspected that the living bone tissue is auxiliary, although it is difficult to prove. There are also several artificial auxiliary substances, especially polymers used in Gore-Tex waterproof clothing.
Poisson's ratio is used in a more complicated way in several fields of science. When you bend the object in one direction, Poisson's ratio affects the way the object curves in a perpendicular direction. The ratio also affects the way the waves travel with substances such as rock, which means that it has some important uses in geology.