Fig. 2.

(a) Approximation of the articular cartilage layer with one and two embedded families of fibers in the superficial and middle zones respectively. θ and κ characterize the mean orientations and the dispersion of the collagen fibers. (b) Example of undeformed finite element model of axisymmetric cartilage indentation. The indenter radius r’ = 0.25 mm, the cartilage radius R = 6 mm, and the thickness h varied in the range 0.41–0.6 mm. The heavy line indicates the boundary between the mesh for the superficial and middle zones.