ABSTRACT
This chapter describes that a Viscoplastic model has been used to model a filled natural rubber vulcanizate. It presents new experimental data for the lateral and longitudinal dynamic stresses when a pure shear test piece is cycled. The Fletcher-Gent effect for the longitudinal stresses is clearly predicted by the simulations and also the related effect for the transverse stresses, suggesting the model employed is capable of predicting the dynamic behaviour of filled rubber under biaxial cyclic conditions. The chapter also examines the "Overlay" method by the finite element simulation of the response of a filled rubber to more general deformations than the uniaxial simple shear. In the case of the combined extension and torsion of a cylinder, it was concluded that modelling filled rubber as a hyperelastic material can also lead to a serious underprediction of the stresses needed to bring about small changes in strain for a state of finite strain.
