Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/214763

Title

Management and understanding of rolling contact fatigue: WP1: mechanisms of crack initiation: WP2: crack growth: literature survey

Author(s)

Kapoor, A.;  Fletcher, D. I.;  Franklin, F. J.;  Beagles, A. E.;  Burstow, Mark;  Allen, R.;  Evans, G.;  Jaiswal, J.

Abstract

This review identifies the current understanding in the scientific community and railway industry of what causes rolling contact fatigue fracture and the factors that influence it. Recent scientific work has revealed the complexity of the RCF mechanisms that interact on different length scales and that require vast amounts of materials data to model. Rolling contact fatigue cracks initiate in wheels and rails due to the repeated application of high loads. The mechanisms of wear and cracking are closely related, with each typically starting from small surface cracks. If the micro cracking that initiates in the surface material of all rails throughout the network propagates downward, then it will result in cracking, otherwise in wear. The likely outcome depends on many factors: the magnitude of the load, slip, lubrication, rail material and microstructure, etc. The critical parameter is the amount of energy that is transferred into the rail and this can be estimated using modern train dynamics software such as Vampire. How the energy affects the rail material can be studied using twin-disc tests, but any model that is to be used to predict the incidence of RCF cracking requires validating against track data. Models that attempt to be more sophisticated or give an impression of having theoretical justification have been developed, but they include parameters that are determined empirically, unknown, or assumed to be constant (such as crack-face friction, shakedown limits, and various material parameters on various length scales).

Publication type

Report

Source

Engineering: management and understanding of rolling contact fatigue: literature review (Feb 2006)

Publication year

2006

Keyword(s)

Crack-face friction;  Crack initiation;  Fatigue cracks;  Microstructure;  Load;  Lubrication;  Rail material;  Rolling contact fatigue;  Slip;  Train dynamics software;  Wear

Publisher

Rail Safety and Standards Board

Publisher URL

http://www.rssb.co.uk/

Copyright

Copyright © 2006 Rail Safety and Standards Board. This publication may be reproduced free of charge for research, private study or for internal circulation within an organisation. This is subject to it being reproduced and referenced accurately and not being used in a misleading context. The material must be acknowledged as the copyright of Rail Safety and Standards Board and the title of the publication specified accordingly. For any other use of the material please apply to RSSB's Head of Research and Development for permission.