Influence of variable stress ratio during train operation on residual fatigue lifetime of railway axles

Pokorný, Pavel; Náhlík, Luboš; Hutař, Pavel

Influence of variable stress ratio during train operation on residual fatigue lifetime of railway axles

Files

1s2.0S2452321616304668main.pdf(1.42 MB)

Date

2016-01-01

Authors

Pokorný, Pavel

Náhlík, Luboš

Hutař, Pavel

Publisher

Elsevier

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Abstract

Railway axles are subjected to cyclic loading, which could lead to fatigue failure. Therefore, it is desired to know residual fatigue lifetime of railway axles to ensure safe operation of trains. Because of detection of relatively small fatigue cracks is not guaranteed an estimation of residual fatigue lifetime is based on damage tolerance approach. The acting stress ratio is variable due to variable amplitude loading and load caused by existence of press-fitted wheel in the vicinity of assumed crack. The contribution is focused on influence of variable stress ratio in EA4T steel on residual fatigue lifetime of railway axles. The influence of stress intensity factor on fatigue crack propagation rate was experimentally evaluated for three different stress ratios, which correspond to operation conditions. Two different expressions of fatigue crack propagation rate were used and mutually compared to show influence of the stress ratio on residual fatigue lifetime of structure made of EA4T steel. The first expression considers stress intensity factor range (respecting stress ratio R) and the second one uses maximal value of the stress intensity factor. The paper shows ability of both expressions to describe experimental data obtained under different stress ratios and their influence on estimated residual fatigue lifetime values. The results obtained contribute to the better estimation of residual fatigue lifetime of railway axles and generally to the safer rail transportation. Copyright (C) 2016 The Authors. Published by Elsevier B.V.

Keywords

railway axle, stress ratio, EA4T, fatigue crack

Citation

Procedia Structural Integrity. 2016, vol. 2, issue 1, p. 3585-3592.
https://www.sciencedirect.com/science/article/pii/S2452321616304668

Document type

Peer-reviewed

Document version

Published version

Language of document

en

Document licence

Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/