  A three-dimensional unilateral contact problem for articular cartilage layers
attached to subchondral bones shaped as elliptic paraboloids is considered in
the framework of the biphasic cartilage model. The main novelty of the study is
in accounting not only for the normal (vertical), but also for tangential
vertical (horisontal) displacements of the contacting surfaces. Exact general
relationships have been established between the contact approach and some
integral characteristics of the contact pressure, including the contact force.
Asymptotic representations for the contact pressure integral characteristics
are obtained in terms of the contact approach and some integral characteristics
of the contact zone. The main result is represented by the first-order
approximation problem.
