The evaluation of a reliable validation method, criteria and limit values suitable for model validation in the context of vehicle acceptance was one of the objectives of the DynoTRAIN project. The presented investigations represent a unique amount of testing, simulations, comparisons with measurements, and validation evaluations. The on-track measurements performed in four European countries included several different vehicles on a test train equipped to simultaneously record track irregularities and rail profiles. The simulations were performed using vehicle models built with the use of different simulation tools by different partners. The comparisons between simulation and measurement results were conducted for over 1000 simulations using a set of the same test sections for all vehicle models. The results were assessed by three different validation approaches: comparing values according to EN 14363; by subjective engineering judgement by project partners; and using so-called validation metrics, i.e. computable measures developed with the aim of increasing objectivity while still maintaining the level of agreement with engineering judgement. The proposed validation method uses the values computed by analogy with EN 14363 and provides validation limits that can be applied to a set of deviations between simulation and measurement values.

Abstract:A methodology for simulating wear, rolling contact fatigue, and plastic deformation for a mixed traffic situation in switches and crossings (S&C) has been developed. The methodology includes simulation of dynamic vehicle-track interaction considering stochastic variations in input data, simulation of wheel-rail contacts accounting for non-linear material properties and plasticity, and simulation of wear and plastic deformation in the rail during the life of the S&C component. To find means of improving the switch panel design, the geometry of a designed track gauge variation in the switch panel has been represented in a parametric way. For traffic in the facing and trailing moves of the through route, an optimum solution was identified and then validated by evaluating a wide set of simulation cases (using different wheel profiles). The optimum design includes a 12 mm maximum gauge widening. Several crossing geometries were investigated to find an optimal geometric design for the crossing nose and wing rails. The MaKüDe design showed the best performance for moderately worn wheel profiles in both running directions (facing and trailing moves). In connection with reduced support stiffness (e.g. elastic rail pads), this crossing design is predicted to lead to a significant reduction of impact loads and consequently provide a high potential of life-cycle cost reduction.

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The project DynoTRAIN, which was funded under the European Seventh Framework Programme, was set-up in order to close the open points in the Technical Specification of Interoperability (TSI) of the trans-European rail system. The project was divided in seven work packages. The focus in work package 3 (WP 3) was the contact geometry between wheels and rails. More general information about the DynoTRAIN project is given in the foreword of this special edition. WP 3 was split into several tasks. In the first and second tasks worn wheel and rail profiles were collected. Since the wear behaviour of wheels and rails depends (among other factors) on bogie design, operating conditions, rail inclination and curve radius, a large number of wheel and rail profiles were investigated in order to obtain a representative picture of the contact conditions on the trans-European network. The wheel and rail profiles were analysed in terms of equivalent conicity, which is an important indicator for the running stability of railway vehicles. Based on the collected data, reference profiles for wheels and rails were defined for the calculation of conicity maps. The reference wheel and rail profiles act as a sort of coordinate (scaling) system for the conicity maps. The conicity maps were calculated from selected wheel and rail profiles that had the same frequency distribution as the whole sample. The conicity maps were calculated for different speed categories and for wheels operating on networks with rail inclinations of 1/20 and 1/40. Finally, limit values of the equivalent concity for the authorization of vehicles and in-service limits for tracks were derived from these conicity maps. This approach enabled the open point ‘equivalent conicity’ in the TSI: Locomotives and Passenger Rolling Stock and TSI: Infrastructure to be closed.