The running gears of DLR's long-term project Next Generation Train utilize independently rotating wheels with mechatronic track guidance, direct drives close to the wheels and are optimized for low weight. On the basis of encouraging research results so far, DLR decided to design and build a true scale prototype of the NGT running gear and use it as a research facility. It is the intention to improve, validate and demonstrate the mechanical and mechatronic design, sensor and actuator lay-out step by step and finally approach the Technology Readiness Level 6. By the end of 2022, this prototype will be put into operation considering low speed scenarios up to max. 5 m/s at an in-house integration test rig. This is the current task, which is reported on in the paper. However, this work is supposed to prepare advanced performance experiments up to 350 km/h on external roller rigs and at railway test tracks later on.

For the reliable simulation-based fatigue design of railway vehicles, the operation conditions and resulting loads over the lifespan of the vehicle have to be considered. After introducing the relevant fatigue loads on the vehicle and the methods for modelling the fatigue damage, this work aims at analysing the influence of the operating conditions and loads on the damage using sensitivity analysis. Two approaches are studied: the variance-based sensitivity analysis of the loads acting on the car body and the influence of different operating conditions using statistical values per track section. The loads are obtained from multi-body simulations and the damage is estimated using both physical FE-models and meta-models. The performances of linear regression models and polynomial chaos models are evaluated. The proposed sensitivity analysis is applied to the highspeed train being developed in the Next Generation Train (NGT) project at DLR and will serve as a basis for the virtual design and reliability analysis.

The newly released commercial DLR RailwayDynamics Library is intended to support the design, optimization and control development as well as hardware-and software-inthe-loop testing of railway vehicles mainly on the system level. To this aim, it provides the capability to consider vehicle dynamics issues such as traction, comfort and safety in multi-domain engineering tasks by preparation of vehicle, track, wheel-rail contact models and roller rig scenarios on different levels of detail. Exploiting several precursor papers on specific railway modeling topics, their models have been collected and reorganized in order to propose a sound modeling framework dedicated to railway dynamics. The paper gives an overview on particular concepts and ideas of the library, presents several application examples and discusses two approaches to organize multi-domain modeling.

A full-scale prototype of the Next Generation Train (NGT) running gear with a roller rig installation bench will be built as proof of concept of the running gear and its suitability for high-speed traffic. It will be available as the research platform "Forschungsinfrastruktur NGT-Fahrwerk" (FuN) for the German Aerospace Center (DLR) internal and external research activities.This work presents an innovative method and tool chain to develop application software for the automation of a mechatronic running gear (prototype). The methodology, development, and simulation tools that offer a consistent tool chain from model creation to real-time software and measurement data processing are presented. The model and software structures that are necessary for the software environment are described. The software-in-the-loop environment couples the existing multi-body simulations for the development process with signal-based simulation software using a co-simulation interface. The resulting software-in-theloop simulation environment contains a novel interface layer that translates the mechanical states of the multi-body simulation to pseudo-electrical signals that are read or written by the application software. This makes it possible to develop real-time applications and software structures in software-in-the-loop architectures. The real-time software contains a dedicated model structure of input, processing and output submodels, which is based on signal flow and distinct assignment of tasks. On the rapid-control-prototyping hardware, the real-time software is investigated with a virtual installation bench simulation.