Experimental real-time tracking and diffusion/mechanics numerical simulation of cavitation in gas-saturated elastomers

Abstract

The effect of a gas decompression after saturation on rubbers was investigated with both an experimental and a numerical approach. Experimental results have been obtained with a commercial transparent rubber under hydrogen and a tensile machine fitted with a pressure chamber that allows a spatial and temporal tracking of damage. The influence of the decompression rate and cavity radius have been studied and compared with a numerical model based on the theory of the hollow sphere and the implementation of a Fickean law to have gas diffusion in the material. This multi-scale model was used to temporally predict the response of a spherical cavity in a hyperelastic incompressible material submitted to a coupled gas/mechanical loading. The aim of the study was to understand the gas exchanges between the cavity and the material and to temporally predict with a simple critical stretch ratio criterion when a small cavity can growth to a visible size. The influence of decompression rate, pressure level, cavity radius and position in the sample were discussed and compared with experiments.