Acceptance test for damped railway wheels

In this paper a procedure for quality acceptance of low-noise railway wheels is presented. The low-noise feature is obtained by applying a constrained layer damping through the use of a viscoelastic polymer and a pre-formed constraining plate. The proposed procedure is based on the analysis of the vibration amplitude in resonance conditions and does not use any acoustical measurement, whose use is particularly not advised in industrial workshops. Frequencies to be considered have been chosen with both the analysis of the sound power emitted by the wheel in a semi-anechoic chamber and the analysis of all acoustic frequency responses measured during type tests. The methodology, verified on a reduced set of damped wheels, has shown a sufficient sensibility and proved to be potentially able to highlight the changes in the vibroacoustics characteristics of wheels due to the intrinsic repeatability of the application of the damping panel.