What term describes the phenomenon where a material supports an increasing load after yielding has ended?

The phenomenon where a material supports an increasing load after yielding has ended is referred to as strain hardening. When a material is subjected to stress beyond its yield point, it undergoes plastic deformation. In this state, if the material is further deformed, it can actually increase in strength, allowing it to support higher loads than it could immediately after yielding. This behavior is primarily observed in ductile materials, where the dislocation density increases as the material is deformed, leading to enhanced strength.

The other terms are relevant in the study of material behavior, but they do not describe this specific phenomenon. Ultimate stress refers to the maximum stress a material can withstand before failure. Yield strength refers to the stress at which a material begins to undergo permanent deformation. Ductility describes a material's ability to deform under tensile stress, but it does not specifically relate to the ability to support an increasing load post-yielding. Strain hardening effectively captures the increase in load-bearing capacity after the yielding phase, making it the correct term in this scenario.