Railway Wheelset Lateral Excitation by Track Irregularities

The lateral excitation of a railway wheelset by plan view track irregularities has been investigated experimentally using an elastically suspended model coned wheelset running on rollers moved so as to simulate on-track velocity conditions. J.J. Kalker's force-creepage relationships are used in formulating linear equations of motion from which predictions of wheelset steady-state frequency response are obtained. The measured behavior is predicted very closely when careful control is exercised over the experiment such that the wheel-rail contact parameters are accurately known. This contrasts with attempts to obtain similar correlation from field experiments using full vehicles, which have not been so successful. The results of the present work suggest that this is likely to be a consequence of inaccurate estimation of the operative contact parameters, and/or linearization problems, rather than errors in the basic theoretical description of the wheelset excitation mechanism.