Numerical modelling of oxidative ageing in deformed state

Abstract

This contribution deals with diffusion-limited oxidative ageing of rubber, namely its numerical modelling. Finite element method (FEM) is used to incorporate oxygen diffusion - and, consequently, inhomogeneous ageing - into the model used in (Heczko, Kottner, & Kossa 2021). The open-source FEM library SfePy (Cimrman, Lukeš, & Rohan 2019) is used for its implementation. The model is based on the framework of the dynamic-network model (Naumann & Ihlemann 2015) and uses the generalized Yeoh model (Hohenberger, Windslow, Pugno, & Busfield 2019a) as the strain energy density function. Similarly to the original paper, the complex material model may be converted into a simplified one, which represents the material at any chosen time instant during the ageing process. This fact is also useful in implementing the material calibration efficiently.