Damage in elastomers: healing of internally nucleated cavities and micro-cracks

Abstract

Following on the work of Poulain et al. (Damage in elastomers: Nucleation and growth of cavities, micro-cracks, and macro-cracks, Int. J. Fract., 2017, 205, 1–21), this paper presents an investigation of the response of cavities/cracks internally nucleated within a transparent PDMS elastomer that is confined between two firmly embedded stiff beads and subjected to quasistatic cyclic loading–unloading. Specifically, it is observed that cracks that nucleate and propagate to reach tens of microns in length during the loading can heal completely upon unloading. They do so autonomously within a time scale of seconds. Furthermore, the regions of the elastomer that experience healing appear to acquire higher strength or toughness.