Interpretation of the high low-strain modulus of filled rubbers as an inelastic effect

摘要

Some strain-energy functions, intended for rubber incorporating reinforcing filler, add a special term onto a more conventional hyperelastic model to fit the rise in stiffness, to very high values, as the strain becomes very small. In this paper the extra term is assigned instead to an "elastoplastic" component in parallel with a hyperelastic component, in a model based on the overlay method used by Austrell (2001). The approach is used to fit models to stress strain curves for representative elastomers, and predictions from the resulting models are compared to the results of cyclic (or "dynamic") stress-strain tests of the materials. The objective is to describe the Fletcher-Gent effect as well as the quasi-static stress-strain behaviour. The end result is a simple fitting procedure distinct from that presented by Olsson (2001) and, it is believed, can provide a useful overlay model for describing the stress-strain behaviour of filled rubber.