Developpement et analyse d'un modele poroelastique et composite du cartilage

The current mathematical descriptions of cartilage mechanical behavior come from the biphasic theory derived from poroelasticity theory of Biot. In the biphasic theory, the complex dynamics of the material arises from the interactions between solid and fluid phases involving relative motion and associated hydrodynamic drag. In the previously developed models, the solid phase was described as homogeneous and isotropic or orthotropic. In this study, we propose a nonhomogeneous composite representation of this structure which, based on the above physiological considerations, is essential to accurately model tissue's mechanical behavior. Using the classical biphasic theory, a nonhomogeneous analytical composite model of the articular cartilage is developed and validated for the case of unconfined compression with frictionless and impermeable platen/cartilage interface. This model considers the medium to be constituted of an isotropic biphasic matrix homogeneously reinforced by a rod-like fibrils network having no resistance in compression. This model was initialy compared to experimental data and to demonstrate the performance of a nonhomogeneous composite representation. The comparison to an equivalent homogeneous transversely-isotropic model has also been made. (Abstract shortened by UMI.)