
378 Computational Modelling of Biomechanics and Biotribology
12.4.3 Friction
One of the challenges in modelling cup xation is consideration of the
aforementioned surface structures. These are hard to model in detail on the
micro-, meso- or macro-level which is why a friction coef cient is assigned
to the corresponding contact pair. In the basic form, the Coulomb friction
model is used to describe the tangential contact behaviour. A contact pair
under tangential load transfers shear stress. The Coulomb friction model
de nes a critical value of shear stress ( τ
crit
) where sliding of the surfaces
begins, depending on the contact pressure ...