Comparison of Results of Calculations and Measurements of DYSAF-tests, a research project to investigate safety limits of Derailment at High Speeds

Abstract

Test runs have been carried out in Velim, Czech Republic, to analyse derailment conditions at higher speeds up to 160 kph. In the research program ‘DYSAF’ a test running gear was developed which enabled to test derailment of a wheelset in guiding and unloaded conditions. With the aid of a lateral force actuator static and dynamic Y/Q derailment situations were measured for different velocities and angle of attack. In this paper a comparison of test and simulation results of the multi body program MEDYNA is presented. Identifying the parameters of nominal wheel loads of the test running gear and friction coefficients in tread and flange simulation results show a very good and promising agreement for the compared signals. Only higher frequency terms are lacking. To include them dynamic properties of track, hydraulic device and wheel roundness have to be improved. Derailment simulation with a MBS tool is a possibility to analyse derailment cases and to develop safety criteria against derailment of railway vehicles. Necessary is a wheel-rail element, which can describe multi non-elliptic contact patches in tread and flange, which can describe creepages in curved contact patches and which uses an extended creep force theory for non-elliptic contact patches. The wheel-rail element of ArgeCare is such an element.