How is 'thermal stress' defined?

Thermal stress is specifically defined as the stress induced in a material as a result of changes in temperature. When a material experiences temperature fluctuations, it expands or contracts. If this thermal expansion or contraction is constrained by the surrounding environment or structure, internal stresses can develop, leading to potential failure or deformation of the material. This phenomenon is particularly relevant in construction and structural engineering, where varying temperatures can cause significant stress in metals and other materials used in buildings and infrastructure.

The other definitions provided relate to different types of stress. For instance, stress induced by structural loads pertains to forces applied to a material, while stress from external forces involves different aspects of mechanical loading. Fatigue stress refers to the weakening of a material caused by repeated loading cycles, which is not directly related to temperature fluctuations. Each of these points of stress is important in material science and engineering, but thermal stress specifically highlights the impact of temperature on material integrity.