Use of the full-network model at the highlight of the logarithmic strain measure

Suitable invariants of the logarithmic strain measure have been defined in order to consider separately a change of loading intensity and a change of loading type. By plotting the classic experimental data of L. R. G. Treloar using this new invariants, some experimental features are found opposite to the standard experimental observations. By using the logarithmic invariants and the macromolecular full-network model, it has been shown that the theoretical response of rubber-like material is independent of the state of strain for small strains. For quantitative comparisons, the full-network model has been tested on the data of Treloar and of James et al. It has shown to give very satisfactory results, provided that the loading history is taken into account: because of the Mullins effect, the hyper-elastic response of rubber-like materials depends on the maximum loading applied yet. For Treloar's data, for which the material had been prestrained differently according to the applied loading type, the material parameters depend on the loading type.