@CONFERENCE\{IMM2012-06374,
    author       = "L. E. Christiansen and H. True",
    title        = "On the dynamics of railway vehicles on tracks with lateral irregularities",
    year         = "2012",
    pages        = "193-202",
    booktitle    = "12th Mini Conference on Vehicle System Dynamics, Identification and Anomalies, Budapest, November {8-}10, 2010",
    volume       = "",
    series       = "",
    editor       = "",
    publisher    = "Budapest University of Technology and Economics",
    organization = "",
    address      = "",
    note         = "Edited by Prof. Istvan Zobory",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/6374-full.html",
    abstract     = "We examine theoretically the dynamics of the rollling motion of the loaded Cooperrider bogie model running on a straight and horizontal track with laterally sinusoidal irregularities. Both lateral and vertical degrees of freedom are included in the bogie model in order to allow for a coupling between the horizontal motion and roll, pitch and vertical motion. The car body however, can only move horizontally and roll. The wavelengths of the irregularities vary between 2.5 and 50 m with amplitudes up to 10 mm. The wavelengths are the same in both rails. We have investigated the two situations when the disturbances of the two rails are in phase and when they are half a wavelength out of phase. Theses cases correspond to a centre line and a gauge variation respectively. The results show that there is a high correlation between the lateral motion of the wheel sets and the centre line irregularities in most cases. They also demonstrate that only certain selected choices of forcing wavelengths and amplitudes of the gauge irregularities make the bogie oscillate for a fixed speed. In the other cases the bogie follows the centre line. The bogie oscillations are in the most cases symmetric, but we have also found many asymmetric motions, including phase locked synchronized oscillations with a period, which is an integer submultiple of the period of the forcing. In a few cases we find aperiodic motions that are presumably chaotic. Statistical methods are applied for the investigation. In the case of sinusoidal oscillations they provide information about the phase shift between the different variables, and they yield the amplitudes of the oscillations. In the case of aperiodic motion the statistical measures indicate some non-smooth transitions.",
    isbn_issn    = "9789633130582"
}