Multibody Dynamics with Unilateral Constraints and Dry Friction: How the Contact Dynamics Approach May Handle Coulomb's Law Indeterminacies?

摘要

For the numerical simulation of mechanical systems subjected to unilateral constraints, the Contact Dynamics approach has been developped by J. J. Moreau since the mid 80's. The core idea consists in applying a discrete contact law S to the left ``free" velocity computed at each time-step. The mapping S should of course mimic the behavior of the system in case of contact. But, when dry friction occurs, the dynamics may exhibit indeterminacies of Painleve's paradoxes type. Then a natural question arises: how a deterministic discrete contact law may handle such phenomena? An answer has been given through numerical experiments by J. J. Moreau and is subtanciated in this paper by introducing the notions of asymptotic consistency of the discrete contact law with respect to Coulomb's friction and asymptotic indeterminacy of the scheme.