Anelastic materials

Anelastic materials are materials that exhibit a delayed or time-dependent response when subjected to stress or strain. Unlike perfectly elastic materials, which instantly return to their original shape after the stress is removed, anelastic materials absorb some energy and recover gradually over time. This behavior results from internal processes, such as internal friction or molecular rearrangements, that dissipate energy as heat. Anelasticity is important in understanding how materials behave under cyclic loads, vibrations, or long-term stresses, especially in engineering applications like earthquake-resistant structures, damping systems, and seismic studies.