This thesis describes the development and validation of a versatile and Flexible Track System Model (FTSM) and its integration into a commercial railway vehicle dynamics software tool. The work was initiated to fill a gap in current disciplines and tools used to investigate problems relating to vehicle and railway track dynamics due to a lack of correlation between Finite Element (FE) and MuItibody System (MBS) based models. The. FTSM track model was validated against results from laboratory testing and compared with existing models. It was then used to study several aspects of the deterioration of ballasted track under the dynamic loading of passing vehicles at speeds, including consideration of the non-linear nature of the track support condition such as sleeper voiding and variable sleeper support stiffness. . The research contributes to the fundamental understanding of the vehicl~-track interaction forces and particularly to the relation that exists between wheel-rail contact forces and track forces. It shows that.in order to accurately predict track degradation forces, a detailed flexible track model is essential. The major differences in terms of wheel-rail contact condition and forces obtained from the conventional simplified track models and from the FTSM are also highlighted. The presence of higher frequency modes of vibration of the flexible track proves essential for those studies involving local and sudden track events. The model was also applied to the analysis and design development of innovative track structures that seem to offer several advantages with respect to conventional ballasted tracks, most importantly a more consistent or continuous support to the rail. This characteristic is shown to be essential for minimising the interactive cycle of dynamic interaction forces and track deformation leading to track settlement and deterioration.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:502435 |
| Date | January 2008 |
| Creators | Bezin, Yann |
| Publisher | Manchester Metropolitan University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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