Creep test measures strains caused by a specific load, i.e. a definite force, in a certain range
of time. This phenomenon is analyzed using a Voigt model (Fig 3).
Figure 5. (a) Four-element model for creep and creep recovery; (b) creep and creep recovery.
OA: Instantaneous strain; AB: Time dependent opening; BC: Instantaneous recovery (=OA); CD: Slow
recovery; EF: Permanent deformation.
Stress-relaxation test
Maxwell model
Stress
Time
Time
Strain
(a)