A thorough investigation of wheel-rail impact due to wheel flats is presented, together with a quantitative characterization of the main mechanisms and parameters. A criterion for the speed with respect to contact loss between wheel and rail is derived. In the subcritical speed regime, the magnitude of the impact force is shown to be directly related to the geometry of the flat, whereas in the transcritical speed regime a fictitious or effective flat depth exists, which decreases with the second-order of the speed. In this domain, the position of impact shifts towards the end of the flat with increasing speed. The impact force increases with the second-order of the speed in the subcritical speed regime and approximately the first-order of the speed in the transcritical speed regime. The magnitude of the impact force is inversely proportional to the minimum circumferential curvature of the wheel tread defect in the subcritical speed regime, and to the effective minimum curvature in the transcritical case. The variation with the flat depth is less; the impact vanes with the square root of the flat depth. The presented theory is in accordance with measurements reported in the literature and explains characteristic features in them.
The role of the contact geometry in wheel-rail impact due to wheel flats
Der Einfluss der Berührungsgeometrie infolge der Flachstelle auf den Rad-Schienen-Kontakt
Vehicle System Dynamics ; 45 , 12 ; 1097-1116
2007
20 Seiten, 18 Bilder, 16 Quellen
Aufsatz (Zeitschrift)
Englisch
The role of the contact geometry in wheel–rail impact due to wheel flats
Taylor & Francis Verlag | 2007
|The role of the contact geometry in wheel-rail impact due to wheel flats
Online Contents | 2007
|The role of the contact geometry in wheel-rail impact due to wheel flats: Part II
Online Contents | 2008
|The role of the contact geometry in wheel–rail impact due to wheel flats: Part II
Taylor & Francis Verlag | 2008
|The role of the contact geometry in wheel-rail impact due to wheel flats: Part II
Tema Archiv | 2008
|