Strain

When a structure or component is subjected to stress individual fibres or elements in the material either lengthen or shorten. Strain is a measure of how much these elements extend or contract, and is defined as the change in length divided by the original length of the element. Strains can be defined at a point if the strained element is considered to be of infinitesimal size.

where

ε = strain

e = extension [m]

l = original length [m]

See also: Axial Strain, Elasticity, Fatigue, Hookes Law, Proportional Limit, Strain Energy, Strain Gauge, Stress, Stress-Strain Diagram, True Strain, Yield Strain, Young′s Modulus.