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642 653 309 1 ; S ; [EN] As it is well known, there are various phenomena related to railway train-track interaction, some of them caused by the high frequency dynamics of the system, such as rolling noise when the vehicle runs over the track, as well as squeal noise and short-pitch rail corrugation for curved tracks. Due to these phenomena and some others unsolved so far, a large effort has been made over the last 40 years in order to define suitable models to study the train-track interaction. The introduction of flexibility in wheelset and rail models was required to have a more realistic representation of the wheel-rail interaction effects at high frequencies. In recently published train-track interaction models, the rails are modelled by means of Timoshenko beam elements, valid up to 1.5 kHz for lateral rail vibration and up to 2 kHz for vertical vibration. This confines the frequency range of validity for the complete train-track model to 1.5 kHz. With the purpose of extending the range of validity above 1.5 kHz, a 3D track model based on the Moving Element Method (MEM) is developed in this paper to replace the Timoshenko beam considered in earlier studies, adopting cyclic boundary conditions and Eulerian coordinates. The MEM approach considers a mobile Finite Element (FE) mesh which moves with the vehicle, so the mass of the rail flows with the vehicle speed but in the opposite direction through the mesh. Therefore, the MEM permits to fix the contact area in the middle of a finitely long track and to refine the mesh only around the contact area, where the forces and displacements will be more significant. Additionally, a modal approach is adopted in order to reduce the number of degrees of freedom of the rail model. Both strategies lower substantially the computational cost. Simulation results are presented and discussed for different excitation sources including random rail roughness and singularities such as wheel flats. All the simulation cases are carried out for a Timoshenko beam and a 3D MEM track ...

[EN] This paper presents a virtual test method for structure-borne noise generated from railway running gear. This method combines a number of existing tools to form a system approach. The wheelset and bogie frame are modelled using FEM software Nastran to include details of their construction. The primary springs are simplified to standard CBUSH elements in Nastran with point and transfer stiffness modelled by frequency-dependent complex stiffness, which are tuned against measurements. The wheel-rail contact forces due to roughness excitation are obtained by the wheel-rail interaction tool TWINS. The vibration of the full running gear is simulated in Nastran by applying the wheel-rail contact forces. The forces transmitted to the vehicle body through traction bars and dampers are calculated for predicting structure-borne noise. ; The work presented in this paper has received funding from the Shift2Rail Joint Undertaking under the European Union's Horizon 2020 research and innovation programme under grant agreement no. 777564. The contents of this publication only reflect the authors¿ view and the Joint Undertaking is not responsible for any use that may be made of the information contained in the paper. Provision of vehicle data from CAF Spain is gratefully acknowledged. ; Xie, G.; Rissman, M.; Bouvet, P.; Liu, X.; Thompson, DJ.; Baeza González, LM.; Moreno, J. (2021). Virtual test method of structure-borne sound for a metro bogie. Springer Nature. 186-193. https://doi.org/10.1007/978-3-030-70289-2_18 ; S ; 186 ; 193 ; Thompson, D.: Railway Noise and Vibration: Mechanism, Modelling and Means, 1st edn. Elsevier, Oxford (2009) ; Thompson, D., Hemsworth, B., Vincent, N.: Experimental validation of the TWINS prediction program for rolling noise, part 1: description of the model and method. J. Sound Vib. 193, 123–135 (1996) ; Report: Deliverable 4.2 – Complete virtual test method for structure-borne and airborne noise transmission, EU Shift2Rail/H2020 project RUN2rail (2019) ; MSC NASTRAN Quick reference guide (2018)