About a stability conjecture concerning unilateral contact with friction

A new notion of stability specially adapted to systems with unilateral contact and Coulomb friction is introduced. Whereas classical stability results in mechanics concern perturbations of the initial data in a classical phase space, we establish here results concerning the trajectories issued from a perturbation of the external forces. In such a context we state a conjecture concerning stability with respect to external forces that we back up by analytical computations in the case of simple models and then by numerical computations for more complex systems.