A model for the viscoelastic behavior of polymers at finite strains

摘要

A constitutive model is derived for the isothermal nonlinear viscoelastic response in polymers, which do not possess the separability property. The model is based on the concept of transient networks, and treats a polymer as a system of nonlinear elastic springs (adaptive links), which break and emerge due to micro-Brownian motion of chains. The breakage and reformation rates for adaptive links are assumed to depend on some strain energy density. The visocelastic behavior is described by an integral constitutive equation, where the re- Laxation functions satisfy partial differential equations with coefficients depending on the strain History.