Elasticity (physics)

Main Article
Discussion
Related Articles  [?]
Bibliography  [?]
When the amount of deformation is directly proportional to the applied load, the material is said to be lineraly elastic. In most engineering use, considering elastic materials as linearly elastic is an acceptable approximation. When a material is linearly elastic, its elastic behavior is governed by Hooke's Law: ${\displaystyle \sigma =E\epsilon }$, where ${\displaystyle \sigma }$ is the applied stress, ${\displaystyle \epsilon }$ is the strain, and E is the modulus of elasticity.
Most materials loaded in compression or tension in one direction will expand or contract in the directions perpendicular to the applied stress. The ratio of lateral strain to axial strain under a given load is Poisson's ratio, ${\displaystyle \mu }$.