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