A numerical 3D model to study ratcheting damage of a tramcar line

A damaged rail may severely influence passenger comfort and the safety of the vehicles that run on it. The typical damages observed on rails are wear and cracks resulting from the dynamic interaction with vehicle wheels. In order to decrease the high costs borne by transportation authorities for track maintenance, predictive maintenance planning could prove to be very useful. This paper deals with a numerical three-dimensional (3D) model for the prediction of tramline rail damage phenomena. This model is not only useful in terms of planning maintenance and inspection intervals on the rails, but also enables to demonstrate how a specific tramcar vehicle influences rail damage, thus enabling to provide some suggestions regarding the design of tramcars that could have a less aggressive impact on the line. In this paper, starting from the contact forces due to the dynamic interaction between the wheels and the rails calculated by means of a multi-body model of tramcar vehicles, a ratcheting analysis of the rails was carried out. Although a specific running condition (i.e. a curved track with a 50 m radius) was analysed, the numerical 3D model is valid for general conditions and, in terms of impact on the line, can be used to evaluate the performance of existing and future tramcar vehicles.