lämpöjännitykseen

Lämpöjännitys, known in English as thermal stress, is the internal stress that develops within a material when it is subjected to temperature changes. This stress arises because most materials expand when heated and contract when cooled. If this expansion or contraction is restricted, either by the material's own internal constraints or by external factors, internal forces are generated.

These internal forces manifest as stress. When a material is heated and unable to expand freely, it experiences compressive stress. Conversely, when a material is cooled and unable to contract, it experiences tensile stress. The magnitude of the thermal stress depends on several factors, including the coefficient of thermal expansion of the material, the change in temperature, and the degree of constraint.

Thermal stresses can have significant practical implications. In engineering, they are a crucial consideration in the design of structures and components that experience varying temperatures, such as bridges, pipelines, engines, and electronic devices. Unmanaged thermal stress can lead to deformation, cracking, or even catastrophic failure of the material or structure. Engineers often employ strategies like expansion joints, material selection with appropriate thermal properties, and controlled cooling or heating processes to mitigate the detrimental effects of thermal stress.