A viscoelastic constitutive modeling of rubber-like materials with the Payne effect

Abstract

• A damage visco-hyperelastic constitutive model is proposed. • The non-monotonous variation of loss modulus of rubbery materials is explained. • The thermodynamic dissipation processes behind Payne effect are studied. • An effective and simple method is developed to identify material parameters. This paper aims to present a viscoelastic constitutive model of rubber-like materials, which can capture the Payne effect under dynamic cyclic loadings. The Payne effect is induced by a damage process of bond rupture inside the rubber-like materials, which leads to the storage and loss moduli changing with the dynamic strain amplitude. A viscoelastic constitutive relation is established based on the nonequilibrium thermodynamics for the rubber-like materials by constructing the Helmholtz free energy as the superposition of a hyperelastic model and a convolution viscous model. The neo-Hookean hyperelastic model and the convolution viscous model in terms of the Prony series are then employed in a modification that the material parameters concerned are treated as internal variables and can be identified through a simple but effective approach. At last, the Payne effect is effectively predicted in a good agreement with experimental results.