Mechanical experimental characterisation and numerical modelling of an unfilled silicone rubber

TLDR

The study analyzes the mechanical behavior of unfilled silicone rubber. The authors performed tensile, shear, compression, plane‑strain, bulge, and perforated‑plate tests on silicone samples, measured surface strains with digital image correlation, fitted five hyperelastic models to the data, and used finite element simulations to evaluate strain fields. The results indicate negligible Mullins effects, hysteresis, and strain‑rate sensitivity, highlight the influence of loading path, and show that the choice of hyperelastic model critically affects simulated strain fields.

Abstract

In this paper, the mechanical behaviour of an unfilled silicone rubber is analysed. Firstly, silicone samples were subjected to five homogeneous tests: tensile, pure shear, compression, plane strain compression and bulge tests. During the tests, full-field measurements of the strain on the surface of deformed samples were obtained using a Digital Image Correlation technique. Results show that the Mullins effects and hysteresis, as well as strain rate sensitivity, can be considered as negligible. Results also emphasise the influence of the loading path. Then, five well-known hyperelastic models (neo-hookean, Mooney, Gent, Haines and Wilson and Ogden models) were fitted to the experimental data. Finally, a heterogeneous test was realised by stretching a silicone plate sample containing holes. Finite element simulations of this experiment have been performed with the hyperelastic models. The comparison of experimental and numerical results emphasises the importance of the choice of the hyperelastic modelling in the simulation of strain fields.