@MASTERSTHESIS\{IMM2003-02501,
    author       = "M. Hoffmann and D. E. Petersen",
    title        = "Dry Friction and Impact Dynamics in Railway Vehicles",
    year         = "2003",
    keywords     = "Nonlinear dynamics, railway vehicle dynamics, dry friction, impact dynamics, differential succession",
    school       = "Informatics and Mathematical Modelling, Technical University of Denmark, {DTU}",
    address      = "Richard Petersens Plads, Building 321, {DK-}2800 Kgs. Lyngby",
    type         = "",
    note         = "Supervisor: Hans True",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/2501-full.html",
    abstract     = "This thesis develops a mathematical model of a Hbbills 311 freight wagon. Central to this model is the {UIC} double-link suspension which incorporates a parabolic leaf spring. The lateral and longitudinal dynamical model of the {UIC} suspension is based on theory by Jerzy Piotrowski. This model successfully takes into account damping due to dry friction in the suspension links.

Parameter identification for Piotrowski's model was performed in Warszaw, Poland, on real {UIC} double linkages. Two sets of parameters were used, the first emphasizing frequency-matching characteristics with the experimental setup, and the second matching theoretical geometric analysis of the suspension joints. Both were used in simulation.

The vertical dynamical model of the {UIC} suspension is discussed, and several models proposed. Results were generated with the implementation of a piecewise linear spring-damper system that takes into account the progressive characteristics of the parabolic spring as well as damping due to dry friction.

The wheelsets are constrained by guidance structures of the freight wagon, and the impacts involving these structures are modelled. Wheel-rail contact forces are calculated using the Shen-Hedrick-Elkins method and a wheel-rail contact geometry table (RSGEO) by Walter Kik.

The wheel profile is the S1002 profile, and the rail profile is the UIC60 profile. All modelling and simulation takes place on straight and level track with a fixed gauge of 1435 mm. Low frequency stability dynamics analysis is carried out. The model is implemented through C++ programming, accessed through the command line or a Java {GUI,} and results analyzed with MatLab."
}