Acoustic comfort in the interior of the trains is a key parameter in the design of modern trains. Moreover, European legislation of interoperability sets limits of interior noise in driver’s cab. New hybrid methodologies including coupling between FEM/BEM/SEA make it possible to carry out useful predictions in an industrial environment. ALSTOM is applying these techniques in the development of modern trains to achieve human friendly products for passengers and train personnel. This paper presents investigation work related to the understanding of how structureborne energy travels through a high speed train structure and radiate noise in the driver’s cab. To understand the physics involved, the « Hybrid FE/SEA » methodology was used. This method allows for a deep understanding of the propagation of energy from the bogie/equipments attachment points to the ear of the driver. Included in this paper there is a preliminary work performed on a high speed train showing the main structureborne paths to focus on. FEM (Finite Element Method) vibration simulation is correlated with experimental data and the results are presented and compared with vibro-acoustics simulation results using « Hybrid FE/SEA ». Finally, the preliminary results show that the simulation models are predictive since it follows a fixed preset model building process and provide a good level of accuracy against test data.
2009 – NOVEM, Oxford, UK
Joan Sapena (Alstom Transport, Spain)
Denis Blanchet (ESI Group, Germany)