thermomechanical

Thermomechanical is an interdisciplinary term referring to the interaction between thermal and mechanical phenomena in materials and structures. It encompasses how temperature changes induce mechanical responses such as expansion, contraction, and stress, and conversely how mechanical state influences heat generation, transport, and temperature distribution.

In solids, thermomechanics is analyzed through thermomechanical coupling. The governing equations couple the heat equation, describing energy conservation and heat diffusion, with the equations of motion or balance of linear momentum. Constitutive relations link temperature, strain, and stress through properties such as the coefficient of thermal expansion, specific heat, thermal conductivity, and elastic or viscoelastic moduli. In the small-strain, linear regime this leads to thermoelasticity; in more complex materials, thermo-viscoelasticity and phase transformation thermodynamics are involved. Temperature gradients generate thermal stresses; conversely, mechanical work and deformation can alter temperature via dissipation.

Applications span engineering and science: design of components under thermal loading (e.g., turbine blades, engines, structural members), electronic devices where self-heating and thermal cycling drive reliability, additive manufacturing and welding where heat input creates residual stresses, and geophysics where temperature changes interact with rock mechanics. Thermomechanical analysis is also used in materials research to study thermal fatigue, creep, and phase-change materials.

Modeling typically employs numerical methods such as finite element analysis to solve the coupled equations under realistic boundary conditions. Experimental techniques include infrared thermography, digital image correlation, and embedded sensors to measure temperature fields and strains. Understanding thermomechanics is essential for predicting performance, safety, and lifespan of systems exposed to coupled thermal and mechanical loads.