Influence of rail, wheel and track geometries on wheel and rail degradation
Doktorsavhandling, 2015

For more efficient railway maintenance there is a need to increase the understanding of the influence of operational conditions on wheel and rail degradation. To this end, the chosen primary investigation strategy is to employ dynamic multibody simulations, where operational conditions are altered, to estimate the influence on material deterioration. Operational conditions considered are track, wheel and rail geometries; and types of material deterioration that are considered are rolling contact fatigue (RCF) and wear. Track geometry, especially the curve radius, has a large influence on wheel/rail degradation. Smaller curve radii lead to higher degradation. By also considering the influence of lateral track irregularities in curves, a more complicated relationship emerge. Large curve radii and a high level of lateral irregularities lead to an increase in RCF over the length of a curve. For small radius curves, where wear is the dominating damage mechanism, an increase in the level of lateral irregularities leads to a transition towards a mixed RCF/wear regime for the outer (high) rail. The influence of wheel and rail geometries on degradation is studied by parametrisation of wheel/rail geometries, employing a design of experiments scheme to the multibody simulations that determine degradation, and finally by deriving meta-models through regression analysis. The meta-models link estimated degradation magnitudes to key geometric parameters. The advantage of the meta-models is that degradation magnitudes can be evaluated with a very low computational cost. This has the benefit that measured wheel and rail profiles can be ranked based on how detrimental they are. Examples are presented for altered gauge corner and flange root geometries, and also for hollow worn wheels. A field study of RCF of locomotive wheels shows its strong dependence on operational conditions. Seasonal variations in the number of wheel reprofilings are explained in terms of seasonal variations in weather conditions, lubrication practices and rail grinding.

track geometry

rolling contact

rail

railway

Rolling contact fatigue

maintenance

wear

wheel

Sal HA2, Hörsalsvägen 4, Göteborg, Chalmers Tekniska Högskola
Opponent: Prof. Rolf Dollevoet, Faculty of Civil Engineering and Geosciences, TU Delft, The Netherlands

Författare

Kalle Karttunen

Dynamik

The influence of track geometry irregularities on rolling contact fatigue

Wear,; Vol. 314(2014)p. 78-86

Artikel i vetenskaplig tidskrift

A numerical study of the influence of lateral geometry irregularities on mechanical deterioration of freight tracks

Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit,; Vol. 226(2012)p. 575-586

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Identifying the root causes of damage on the wheels of heavy haul locomotives and its mitigation

Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit,; Vol. 228(2014)p. 663-672

Artikel i vetenskaplig tidskrift

Styrkeområden

Transport

Ämneskategorier

Farkostteknik

ISBN

978-91-7597-203-9

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 3884

Sal HA2, Hörsalsvägen 4, Göteborg, Chalmers Tekniska Högskola

Opponent: Prof. Rolf Dollevoet, Faculty of Civil Engineering and Geosciences, TU Delft, The Netherlands