Nitpick: creep is different from relaxation. Creep is when you apply a constant load on the material, and the material elongates (creeps) gradually, keeping th

Nitpick: creep is different from relaxation. Creep is when you apply a constant load on the material, and the material elongates (creeps) gradually, keeping the same stress. Relaxation is when you apply a constant extension to the material, and the stress reduces gradually (material relaxes), keeping the same extension.