  The aim of the paper is to derive the exact analytical expressions for
torsion and bending creep of rods with the Norton-Bailey, Garofalo and
Naumenko-Altenbach-Gorash constitutive models. These simple constitutive
models, for example, the time- and strain-hardening constitutive equations,
were based on adaptations for time-varying stress of equally simple models for
the secondary creep stage from constant load/stress uniaxial tests where
minimum creep rate is constant. The analytical solution is studied for
Norton-Bailey and Garofalo laws in uniaxial states of stress. The most common
secondary creep constitutive model has been the Norton-Bailey Law which gives a
power law relationship between minimum creep rate and (constant) stress. The
distinctive mathematical properties of the power law allowed the development of
analytical methods, many of which can be found in high temperature design
codes. The results of creep simulation are applied to practically important
problem of engineering, namely for simulation of creep and relaxation of
helical and disk springs. The exact analyticalexpressions giving the torque and
bending moment as a function of the time were derived.
