Time-Stress Correspondence in Viscoelastic Materials: an Equation for the
Stress and Temperature Shift Factor:
Witold Brostow
Department of Materials Science,
University of North Texas, Denton, TX
76203-5310, USA
ABSTRACT
Stress-time correspondence principle discovered experimentally by O'Shaughnessy already in 1948 is
considered. Using the Doolittle formula for the viscosity as a function of free volume, an equation
for the generalized temperature-stress shift factor aT,s is obtained.
An equation for the stress-dependent
shift factor as follows as a special case. The equation for the temperature shift factor aT already
derived in 1985 and successfully used since also follows from the aT,s formula.
Keywords Viscoelasticity · Temperature shift factor · Stress shift Factor ·
Polymer property prediction · Polymer reliability · Polymer mechanical properties ·
Time-stress correspondence · Time-temperature correspondence · Thermal mechanical analysis ·
Equation of state · Hartmann equation · Creep compliance
Maintained by Ricardo Simoes