Residual stretch-based model for describing fatigue life of aged elastomers

Abstract

This work presents a novel approach for assessing the impact of thermo-oxidative aging on the fatigue properties of elastomeric materials. Beginning at the microscale, where macromolecular chains undergo shortening through crosslinking, the approach postulates the existence of a residual stretch at the macroscale proportional to aging severity. The proposed approach suggests that aging increases the effective applied load, necessitating correction to accommodate the additional strain.

This hypothesized microscopic mechanism manifests as a residual stretch that depends on the density of elastically active chains. This framework enables the construction of a unified Wöhler curve that spans both low-cycle and high-cycle fatigue, based on the Bastenaire model. Further validation using data from the literature highlights the effectiveness of this novel empirical approach.