Sliding Contact between Freeform Surfaces

This paper deals with the sliding-contact constraint equations describing the relative motion of two freeform surfaces, assuming that the surfaces can have arbitrary curvature in three-dimensional space. The sliding-contact equations are developed either for the non-penetration condition and for the surface-tangency condition, Both are differentiated twice in time in order to allow a straightforward application to dynamic and kinematic multibody simulation within the context of an augmented Lagrangian approach. This formulation represents the contact constraint by means of a sliding tangent plane, hence exploiting the advantageous optimizations of the so called lock formulation.