A Micro-mechanical Approach to Model Thermo-Oxidative Aging in Elastomers

This paper presents a micro-mechanical approach to describe the effects of thermo-oxidation on the constitutive behavior of aged elastomers at the long-range timescales. In particular, this model focuses on the effects of thermo-oxidative aging on the quasi-static mechanical response of elastomer and their inelastic responses such as Mullins effect and permanent set over time. The model is validated with respect to a comprehensive set of experimental data designed by Johlitz et al. to capture thermo-oxidative effect on constitutive behavior of elastomers. Besides accuracy, the model is relatively simple and easy to fit. It requires ten material parameters, all with clear physical meaning, which can be derived from only one set of experiment.