elasticoviscous deformation

Elasticoviscous deformation, also known as viscoelasticity, describes materials that exhibit both viscous and elastic properties when undergoing deformation. When a force is applied, these materials initially deform elastically, meaning they return to their original shape once the force is removed. However, if the force is sustained or increased, the material may undergo plastic deformation, where it permanently changes shape.12

This behavior is time-dependent; a load applied to a viscoelastic material results in an immediate extension, followed by a continuing elongation over time. This phenomenon is crucial in understanding the behavior of materials like polymers, rubber, and even rocks under geological timescales. The study of viscoelasticity is important for analyzing stress waves and damping vibrations.32