Formation Mechanisms and Mitigation

Long-time wear development studies at specific tram lines have pointed out the development of polygonal wheels, which is a widespread problem throughout the different types of rolling stocks. Polygonal wheels result in persistent periodic oscillations of the wheelset, especially in the vertical direction, having a detrimental impact on ride comfort, vehicle–track components, impact noise, ground-borne vibration and the life cycles of the wheels. However, its formation mechanisms are yet not fully understood.

Trams differ from conventional railways essentially and their unique characteristics may lead to specific phenomena. Oscillation phenomena appearing at the wheelset, in particular in curves with a small radius of curvature, may provide a source of possible wheel polygonization. Influence from the shape of the wheel profile is studied, as well as effects from the flexibility of the axle and tram bogie to give examples.

The research project focuses on a fundamental understanding of the mechanisms that may promote wheel polygonization and on possible mitigation measures based on results from measurement reports.

Figure 1: Influence of wheel profile shape on evolution tendency of wheel polygonization; measured wheel polygons at different diameters of the wheel

References

Zehetbauer, Florian, Johannes Edelmann, and Manfred Plöchl. "Influences of tram characteristics on wheel polygonal wear evolution., opens an external URL in a new window" Engineering Failure Analysis 157 (2024): 107528.

Zehetbauer, Florian, Johannes Edelmann, Alois Steindl, and Manfred Plöchl. "Dynamic vibration absorber for the mitigation of potential wheel polygonization at trams., opens an external URL in a new window" Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science (2024): 09544062241229251.

Zehetbauer, Florian, Johannes Edelmann, and Manfred Plöchl. "A minimal model to study self-excited vibrations of a tram wheelset in curves with small radius of curvature., opens an external URL in a new window" Vehicle System Dynamics 61, no. 11 (2023): 2867-2887.

Researcher

• Florian Zehetbauer

Project Funding

Industrial