Hard versus soft impacts in oscillatory systems modeling

The applicability of the soft and hard impact models in modeling of vibro-impact systems is discussed in the paper. We derive the conditions which allow the same rate of energy dissipation in dynamical systems which use both impact models. The advantages and disadvantages of both models in modeling are discussed. We show that in the case of the stiff base both methods give the same results but the elastic base application of the hard impact model leads to wrong results.