Procuring rail vehicles has never been as complex as it is today, especially for small and medium-sized operators. Global market consolidation, shrinking supplier pools and increasing technical requirements are pushing many to their limits.
Our latest PROSE white paper shows how you can minimise risks when procuring small fleets through:
Targeted support from experts
Life cycle-oriented procurement planning
Long-term harmonised strategies for rail vehicles
With concrete case studies such as the VDV tram-train tender and the collaboration with MGB, RhB and zb
Clarification of the intended track layout, speed restrictions and wheel/rail profile conditions
Setup of appropriate multi body system (MBS) models of the tracks including the cross-sections of the switch blades as well as three types of existing tram vehicles
Conduction of a variation of MBS simulation runs and extraction of loads acting on track components like e.g. rails, switch tongues; setup of related load assumptions
Setup of a finite element model (FEM) e.g. of the switch tongues and the surrounding structure
Fatigue strength assessment of the track component while applying the loads as gained from the MBS simulations
Proposals of design improvements regarding the strength
Meter gauge tram application
Tracks including deep grooved switches
Our Approach
Running dynamics simulations have been performed to determine the wheel/rail loads, which are acting on the related track components. The specific conditions of WSB have been considered while conducting multi body system (MBS) simulations for all three types of vehicles in all relevant directions of travel through the triangular joint “Sanderring” as well as the tracks in front of the central railway station. As a result, load assumptions for the track components under assessment (e.g. switch tongues) have been extracted from the MBS simulations. A finite element model (FEM) of the component and the surrounding structure was set up. The wheel/rail load assumptions as derived from the MBS simulations have been applied to the FEM model. A fatigue assessment was conducted while analyzing the strength amplitude as deriving from the maximum strength. Based on the FEM results, specific design adjustments have been recommended to improve the strength.
Customer benefit
One major benefit is the minimization of the risk e.g. of occurrence of cracks. This is especially important, as new tram vehicles by tendency come along with higher axle loads and are thus more demanding regarding the strength of track components. Another benefit is the reusability of the load assumptions as well as the strength analysis for future tenders of similar track layouts under comparable conditions. Two of the three MBS vehicle models have already been setup in a former project for WSB. Thus, the benefit of reusability without initial modelling efforts was already used in this project.
