  This paper focuses on the origin of the poroelastic anisotropic behaviour of
the meniscal tissue and its spatially varying properties. We present confined
compression creep test results on samples extracted from three parts of the
tissue (Central body, Anterior horn and Posterior horn) in three orientations
(Circumferential, Radial and Vertical). We show that a poroelastic model in
which the fluid flow evolution is ruled by non-integer order operators
(fractional Darcy's law) provides accurate agreement with the experimental
creep data. The model is validated against two additional sets of experimental
data: stress relaxation and fluid loss during the consolidation process
measured as weight reduction. Results show that the meniscus can be considered
as a transversely isotropic poroelastic material. This behaviour is due to the
fluid flow rate being about three times higher in the circumferential direction
than in the radial and vertical directions in the body region of the meniscus.
In the anterior horn, the elastic properties are transversely isotropic, with
the aggregate modulus higher in the radial direction than in the
circumferential and vertical directions. The 3D fractional poroelastic model is
implemented in finite element software and quantities such as flux of
interstitial fluid during the consolidation process, a non-trivial experimental
measure, are determined.

Numerical Analysis;Numerical Analysis