Elastisk

Elastisk is a term used in several Scandinavian languages, notably Swedish and Norwegian, to describe materials or objects that can be stretched or deformed and then return to their original shape. In English, the corresponding concept is elasticity. The word derives from Latin elasticus, via Greek elastos, and is related to the general idea of springiness and recoverability.

In physics and engineering, elasticity refers to the property of a material to resist and recover from deformation. Key concepts include elastic deformation, which is reversible, and plastic deformation, which is permanent. The intensity of deformation under load is described by stiffness or the Young's modulus, while the relationship between stress and strain in the linear elastic region is approximated by Hooke's law (stress proportional to strain). Materials can be classified as elastic or viscoelastic; viscoelastic materials exhibit time-dependent behavior such as creep and stress relaxation.

Applications span many fields: rubber and polymers, metals in elastic regimes, textile elastics, diaphragms and seals, flexible electronics, and structural components designed to tolerate dynamic loads. In design, engineers account for temperature, strain rate, and aging, all of which influence elasticity.

Measurements of elastic properties are typically performed with tensile or compression tests, dynamic mechanical analysis, or nanoindentation, yielding parameters such as Young's modulus, shear modulus, and Poisson's ratio.