Dynamics problem of mechanical systems with unilateral constraints

Two examples of systems with unilateral constraints are studied in this work. First system concerns a movement of the table tennis ball between rackets with consideration of the air resistance whereas the second one determines a motion of the rolling mill coupling as the result of a clearance existing in one of the universal joints. An elastoplastic type of impact has been considered in both examples what corresponds to the coefficient of restitution (during impact) ranging from zero to one. The initial-value problems for motion of the systems has been formulated and numerically solved. For solving the problem the Runge-Kutta method of numerical integration of equations of motion has been used.