6. Creep and Relaxation of Springs

In this chapter the time-depending behavior of spring elements under steady load is studied. The common creep laws are implemented for the description of material. For basic spring elements the Norton-Bailey, Garofalo and Naumenko-Altenbach-Gorash constitutive models were studied. Analytical models are developed for the relaxation of stresses and creep under constant load. Closed-form solutions of the analytical models of creep and relaxation are found. The explanation of the experimental procedure for the experimental acquisition of creep models is given.