A model for the non-linear viscoelastic behavior of amorphous polymers

摘要

Based on the non-Gaussian full network model in rubber elasticity and the internal-variable theory, a new expression of the (Helmholtz) free energy for an incompressible viscoelastic material is suggested and hence a non-linear viscoelastic constitutive model is proposed in this paper. The obvious advantage of the present model is that only a few material parameters need to be determined, and it can reduce to the non-Gaussian full network model if the deformation process is sufficiently slow (or fast). Comparisons of numerical results with experimental data indicate that the present model can predict the viscoelastic response of amorphous polymers at finite strain with a satisfactory accuracy. (C) 2003 Elsevier Ltd. All rights reserved.