Which term refers to the breakdown of material due to excessive stress?

The term that accurately refers to the breakdown of material due to excessive stress is yielding. Yielding occurs when a material reaches its yield strength, leading to permanent deformation. This concept is critical in materials science and engineering because it signifies the transition from elastic (reversible) behavior to plastic (permanent) behavior in materials under load. When a material yields, it can start to deform and become permanently altered, which is often the precursor to further failure of the material if stress continues to be applied.

Yielding is a key consideration when designing structures or components, as engineers must ensure that the stresses placed on materials stay below their yield strengths to avoid permanent damage and maintain the integrity of the system. In contrast, although fatigue involves the gradual degradation of materials due to cyclic loading over time, it does not refer to immediate breakdown under excessive stress. Creep describes the slow, time-dependent deformation of a material under constant load, while fracture refers to the breaking of materials that can occur after yielding, especially when stress continues to be applied.