thermoelastiseen

Thermoelastinen, in English often called thermoelasticity, is the area of continuum mechanics that studies how temperature variations interact with mechanical deformation in solid materials. The term is used in Finnish texts as the basis for adjectives such as thermoelastinen and the related noun thermoelaisuus, with thermoelaisiin or thermoelastiseen forms appearing as inflected cases in sentences.

The core idea of thermoelasticity is that thermal and elastic fields are coupled: changes in temperature cause strains (thermal expansion), and conversely, mechanical deformation and heat flow influence the temperature distribution within a body. In mathematical models for small deformations, the strain is typically decomposed into a mechanical part and a thermal part, epsilon = epsilon^e + alpha (T − T0) I, where alpha is the coefficient of thermal expansion, T is temperature, T0 is a reference temperature, and I is the identity tensor. The stress-strain relation then reflects this coupling, often written as sigma = C:(epsilon − alpha (T − T0) I) for an elastic solid with C as the elasticity tensor.

Governing equations include the balance of linear momentum, div(sigma) + body forces = rho a, and an energy balance that accounts for heat conduction and thermoelastic coupling. In the classical linear theory, Fourier’s law governs heat flow, yielding a set of coupled partial differential equations for displacement and temperature. Extensions such as generalized thermoelasticity (Green–Lindsay, Lord–Shulman) introduce finite speeds of thermal wave propagation to address non-Fourier effects.

Applications of thermoelastic analysis appear in structural and aerospace components, electronics cooling, manufacturing processes, and any scenario where thermal loads induce stresses or where mechanical work affects temperature distribution. See also thermoelasticity.