A nonlinear vehicle-structure interaction methodology for the assessment of the train running safety

A nonlinear vehicle-structure interaction methodology for the assessment of the train running safety is proposed
in this article. The contact formulation between wheel and rail consists in three main steps: the geometrical problem, where the
contact point position is detected; the normal contact problem, in which the forces are determined based on the Hertz theory, and
the tangential contact problem, where the creep forces are calculated using the rolling friction laws proposed by Kalker. The
behavior in the contact interface is reproduced by a contact element developed for this problem. Constraint equations that relate
the displacements of the vehicle and structure are imposed using a direct method. The formulation is validated using results of
an experimental test performed in a rolling stock test plant of the Railway Technical Research Institute in Japan