Comparability of the non-linear and linearized stability assessment during railway vehicle design

Abstract

This article compares the linearized and non-linear methods of running stability assessment, as they are used in railway engineering. It is demonstrated that both the results of the linear and the non-linear calculations can exhibit perceptible dispersion at one value of equivalent conicity. The comparisons are carried out on two vehicle types, for different calculation methods and wheel/rail contact conditions. It is shown that by applying a minimum damping of 5% and full creep coefficients of Kalker’s linear theory, the linear critical speeds are below the non-linear critical speeds, allowing the application of linearized calculations in preliminary investigations in an early project phase.