Critical time step estimation for three-dimensional explicit impact analysis

A method to obtain a bound on the critical time step of impact problems that employ explicit integration and penalty type contact elements is presented. The method uses a Gerschgorin bound obtained from a partially assembled stiffness matrix for the nodes that belong to elements involved in the contact region. A numerical example is presented to illustrate the method's effectiveness. 6 refs., 4 figs., 1 tab.