Papers by Author: Michał Opala

Abstract: This article describes an example analysis of safety against derailment of a railway vehicle. The analysis is based on the experimental data recorded during measurement of the wheel-rail interaction forces and lateral accelerations. The data is used for the calculation of two safety against derailment indicators and then the indicators are compared to each other. The first indicator is the ratio of the lateral to vertical wheel-rail forces Y/Q, based on the Nadal criteria. The second indicator is given in the energy description. In this description, the derailment of a railway vehicle depends on the amount of the work that has been done by the total lateral force acting on the single wheelset. The second indicator can be particularly convenient for a railway vehicle condition monitoring system, because it does not require the measurement of the contact forces.

Abstract: We shall discuss the problem of rail vehicle safety studies using simulation methods. The contemporary methods and criteria used for safety assessment of railway vehicles by railways Europe are shown, whereas special attention is paid to the criteria and research programs applied to the vehicle approval procedures in Poland. Taking advantage of these safety criteria and codes of practice, a number of computer simulations have been conducted in order to study the safety issues. Presented results of the computer simulations include a rail vehicle running on a tangent and curved track for different simulation parameters such as: running velocity, load level, condition of wheel profiles, track irregularities. The track irregularities represent different maintenance quality levels which are set according to UIC518 code. In this paper there has also been made a comparison between the results of computer simulation safety assessment studies and the measurements taken in real conditions during the safety tests of a Shimmns(s) type freight vehicle.