Structural vibration and sound power radiation modelling for a light train wheel

The noise generating characteristics of a light train wheel has been studied theoretically. Nowadays different approaches using several software tools, present on the market, can be used. This paper shows the different results using two different approaches. One is based on the use of the FEM and BEM methods. The second is based on the well known procedure using the commercial software: TWINS. Both procedures use a FEM model of the wheel. The wheel analysed is a "resilient wheel" in which a visco-elastics layer is located between the type and the web. Particular attention is dedicated to the modelling of the interface between a visco-elastics layer and the two steel parts. The finite elements model is used to calculate the mode shape and the modal masses. The modal damping is predicted by a complex numerical modal analysis of the finite element model in which a material specific damping parameter is used. Experimental modal analysis tests are also executed in order to better identify and confirms the damping values. The FEM modal parameters are used as input in the TWINS software, whose results in terms of global sound power have next been used within a ray tracing noise of the whole vehicle. Comparison of predicted and experimentally measured nose field have been at the end of the activity performed and herein reported.