stressoftening
Stressoftening, also spelled stress softening, refers to the gradual reduction in a material’s stiffness or resistance to deformation when subjected to repeated loading cycles. The phenomenon is most commonly observed in polymeric and rubber‑like materials, where the mechanical response changes after initial plastic deformation or microstructural rearrangement. It is distinct from elastic recovery and from permanent set; rather, it describes a nonlinear, history‑dependent softening that can be measured in stress–strain curves.
The first systematic studies of stress softening appeared in the early twentieth century during investigations of
From a materials‐science perspective, stress softening can be modeled using nonlinear viscoelastic frameworks, such as the
Industries that rely heavily on elastomeric components—automotive suspension bushings, shock absorbers, wearable sensors—monitor stress softening to
Understanding and controlling stressoftening remain active research areas, especially for next‑generation materials such as shape‑memory polymers,