NONLINEAR VISCOELASTICITY OF A VULCANIZED ELASTOMER

The material nonlinearities in the viscoelastic behavior of rubbers at modest-to-large deformations have been studied. A vulcanized network based on the styrene-butadiene elastomer has been tested in stress-rel axation experiments at room temperature for a wide range of deformatio ns. After time-strain separabality was confirmed, the damping function could be calculated and introduced into the Boltzmann superposition i ntegral. The equilibrium stress-strain behavior of the system could th en be described, while comparison with other theoretical equations has also been made. (C) 1994 John Wiley and Sons, Inc.