The directional instability problem in systems with frictional contacts Original Research Article

The research summarized in this paper addresses the directional instability of finite dimensional systems with unilateral frictional contacts. Conditions for the occurrence of this divergence type instability are discussed, complementarity formulations are developed, and numerical procedures are proposed for the solution of the corresponding non-smooth stability eigenproblems. Various examples are analytically or numerically solved and discussed, namely some finite element examples that have instability modes involving evolution towards slip or stick in different portions of the contact surface.