What is the term for a material that strains slowly when a force is applied over extended periods, even if the force is too small to cause failure in a short time?

The term you are looking for, which describes a material that deforms gradually under a sustained load over time, is indeed creep. Creep is particularly relevant in materials science and engineering, as it affects how materials behave under long-term stress conditions, especially in structural applications. When a constant or low-level stress is applied to a material, it may start to strain or deform slowly, even if the stress is not sufficient to cause immediate failure.

This phenomenon is crucial to consider during the design and analysis of structures that are subjected to prolonged loads, such as beams or components in buildings, bridges, and machinery. Understanding creep allows engineers to ensure safety and functionality over the life of a structure, preventing unexpected deformations that could lead to structural failure.

The other terms provided refer to different concepts. Yield stress relates to the stress level at which a material begins to deform plastically and will not return to its original shape once the load is removed. Elasticity describes the ability of a material to return to its original shape after being deformed when the load is removed. Fracture indicates a complete failure of the material, often associated with sudden breaks or cracks under stress. Each of these terms has distinct definitions and applications that do not capture the gradual deformation associated