Dynamics of European two-axle freight wagons | Mark Hoffmann
| | Abstract | In this thesis the fundamental dynamic behaviour of European two-axle railway freight wagons is investigated with special attention to their unwanted hunting motion on straight track. A model of a single two-axle freight wagon running on a general curvilinear track is developed and described in detail. Essentially, the model is a system of ordinary differential equations. The nonsmooth characteristics of the interacting forces are challenging both in the modelling phase as well as in the formulation of an appropriate numerical integration strategy to extract the solution from the system of differential equations. The model is appropriately divided into states, such that the nonsmoothness in the model is defined by the switching boundaries between the states. These switching boundaries are located by the numerical integration procedure allowing one to find the solution efficiently and accurately.
The model is analysed for different parameters (wheelbase, suspension parameters, rail inclination etc.). The solution space is shown to have several attractors emphasising the intricate dynamic properties of these wagons. In summary, if the wagon is running at high speed the wheelsets are attracted to a flange-to-flange motion. This violent motion is not transferred to the carbody if the lateral excitation frequency of the wheelsets is far from the yaw eigenfrequency of the carbody. However, the two-axle freight wagon can experience a resonance motion at either low, medium or high speed when the previously mentioned frequencies coincide. Here, the wheelsets are not necessarily moving from flange to flange but the carbody has a severe lateral and yaw motion. | | Type | Ph.D. thesis [Academic thesis] | | Year | 2006 | | Publisher | Informatics and Mathematical Modelling, Technical University of Denmark, DTU | | Address | Richard Petersens Plads, Building 321, DK-2800 Kgs. Lyngby | | Series | IMM-PHD-2006-170 | | Note | | | Electronic version(s) | [pdf] | | BibTeX data | [bibtex] | | IMM Group(s) | Scientific Computing |
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