Finite Element Algorithm for Frictionless Contact of Porous Permeable Media Under Finite Deformation and Sliding

Contact problems are fundamental to the study of biological tissues, especially in the area of diarthrodial joint biomechanics. Finite element formulations and implementations of the contact mechanics of porous media remain challenging, and only a limited number of studies have proposed solution schemes for these types of problems [1–3]. Unfortunately, finite element codes using these formulations are not generally available to the public. A commonly used commercial finite element implementation of porous media contact is provided by Abaqus FEA (www.simulia.com), which has been used for studying articular contact mechanics [4–6]. This implementation is also able to analyze large sliding and finite deformations. The Abaqus implementation allows the application of a ‘drainage-only-flow’ boundary condition that is inconsistent with conservation of mass across the contact interface. Furthermore, it does not automatically enforce free-draining conditions outside of the contact region while enforcing continuity of the contact traction and fluid flux across the contact interface.