Résumé
Annulus fibrosus (AF) is the outer tissue ofintervertebral discs (IVD). Its peculiarmicrostructure and biphasic composition define byan oriented fibre network embedded in a highlyhydrated matrix (60−70%) is usually assimilated toporous composite material. It confers to AF a nonlinear,viscous and anisotropic behaviour.Many experimental and numerical studiesunderlined the anisotropic and non-linearmechanical behaviours on averaged values[Ambard and Cherblanc, 2009; Malandrino et al,2011] but fail to represent the experimental strainheterogeneities [Baldit et al, 2013a; Michalek et al,2010], that would be related to the microstructureand the biphasic constitution. On the other hand,characterization rarely relies on volumic behaviorbut it’s relevant when models deal with soft porousmedia [Baldit et al, 2013b].This work aims to couple a poro-hyper-elasticmodel identification with homogenized anddiscretized geometries highlighting modelsensitivity and limits regarding experimentaltransverse strains measurements.