On frictionless impact models in rigid-body systems

The paper reviews the frictionless collision problem in rigid-body dynamics. After having established the contact kinematical equations and the impact equations, Newton's and Poisson's impact laws are stated in inequality form for one collision point. This situation is extended by superposition to multi-contact configurations. The concept of superposition together with the equations for a single contact defines the mechanical impact theory. It is valid only within a certain restricted framework specified by several physical assumptions, which are discussed to some extent.