Singularities in differential-algebraic systems with unilateral constraints

Kurzfassung

Inequality (unilateral) constraints may introduce various types of singularities in differential-algebraic systems. In the presnt paper we consider contact conditions that are formualted as unilateral constraints for position and velocity coordinates in a mechanical multibody system. If the surfaces of the bodies being in contact are worn then the contact conditions result often in constraints that are only piecewise differentiable. We discuss a regularizsation that considers qualitatively the elastic deformation of bodies.