ABSTRACT
In this paper, the kinematic study of a large database of published multiaxial fatigue tests on rubber specimens (more than 350 tests) is proposed. The objective is twofold: first, the complete database along with a Python script that permits one to reproduce our investigation can be given on request, hence providing a hands-on database for future research purposes. Second, the present work proposes a discussion about the combination of specimen geometries and type of some loadings prescribed, based on the evolution of an invariant of the Hencky strain (true) tensor: K 3, the level of multiaxiality (or mode of distortion). In the light of these new results, some observations are made: classical solid axisymmetric specimens (AE2, AE42, AN2 and Diabolo) with different radii of curvature mostly achieve a controlled multiaxiality level, rendering them very suitable for characterization purposes. However, care must be taken when running tension tests on the AE2 specimen, as a small curvature radius specimen prevents to achieve a pure uniaxial tension mechanical state (K 3 = 1).
