Effect of track geometrical defects on running safety of tramcar vehicles

Urban rail vehicles can present peculiar problems that require specific analysis of both vehicle dynamics and wheel–rail contact phenomena. This article deals with the numerical–experimental investigations that were performed to evaluate derailment risk, showing the mechanism of flange climb and the conditions that can mainly influence derailment occurrence. In particular, the influence of the dynamic effects related to the vehicle response to track irregularities is investigated, showing that the track’s geometrical defects play a key role with respect to derailment risk.