Adaptation of the semi-Hertzian method to wheel/rail contact in turnouts

Abstract

A procedure is described in order to assess loads applied on a turnout due to track-train interaction. Co-simulation is used between a finite element method (FEM) model of the turnout and a multibody system (MBS) of the vehicle. Wheel/rail contact forces are computed in the MBS and applied to the rails of the turnout modelled as FEM beams. FEM displacements under the wheel are accounted in the MBS in the next time step. A modification has been applied to the semi-Hertzian (SH) method used to assess wheel/rail forces. This adapted SH method is designed to take in account the relative flexibility of the components of the turnout, like the stock rail and the switch rail. Such parts have their own degree of freedom and may in some extent behave independently: the proposed method takes it in account in the contact search. The co-simulation has been first used in a referenced case-study.