An Analytical Model in Frequency Domain for Embedded Rail Systems

The dynamics of railway track plays a fundamental role on the generation of ground-borne vibrations and rolling noise, that are among the main sources of discomfort related to urban railway lines. For this reason, an accurate model to represent the dynamics of urban tracks is needed for the quantitative evaluation of the vibro-acoustical impact of new vehicles or railway infrastructures. Several analytical models for the dynamics of railway tracks exist, but they are not suitable to describe the dynamics of embedded rail track systems, usually adopted for tramways, since they neglect the dynamic coupling between vertical and lateral dynamics. An analytical model for embedded rail systems is proposed and the results are compared with experimental tests on a track section of the Milan tramway network. As a general comment, a good agreement between experimental and numerical results is observed. As far as the track receptance in vertical direction is concerned, differences are highlighted. In this regard non-linearities typical of elastomeric elements seems to affect the overall track dynamics.