Influence of different crack propagation rate descriptions on the residual fatigue lifetime of railway axles

0449783 - ÚFM 2016 RIV CH eng C - Konferenční příspěvek (zahraniční konf.)
Pokorný, Pavel - Náhlík, Luboš - Hutař, Pavel
Influence of different crack propagation rate descriptions on the residual fatigue lifetime of railway axles.
Advances in Fracture and Damage Mechanics XIII. Zürich: Trans Tech publications, 2015 - (Alfaiate, J.; Aliabadi, M.), s. 469-472. Key Engineering Materials, 627. ISBN 978-3-03835-235-8. ISSN 1013-9826.
[FDM 2014 International Conference on Fracture and Damage Mechanics /13./. São Miguel Island, Azores (PT), 23.09.2014-25.09.2014]
Grant CEP: GA MŠMT(CZ) EE2.3.30.0063
Institucionální podpora: RVO:68081723
Klíčová slova: residual fatigue lifetime * fatigue crack * fatigue crack propagation * railway axle
Kód oboru RIV: JL - Únava materiálu a lomová mechanika

The paper deals with an estimation of the residual fatigue lifetime of the railway axles. The railway axles can include some cracks either from manufacturing process or from previous loading operation. Because of cyclic loading of the railway axles there is a risk of fatigue failure of the railway axles with unacceptable consequences. Based on this fact, for conservative establishment of the residual fatigue lifetime of the railway axle is necessary to consider an existing crack in the railway axle during design process. The fatigue lifetime estimation of railway axles is very sensitive to used crack propagation rate description (e.g. v-K curve). Typical bending of this curve (knee) can be found in the vicinity of the threshold value in fatigue crack propagation rate dependence (typically v-K curve expressed in log-log coordinates). For accurate estimation of residual fatigue lifetime of the railway axle is necessary to use approximation of v-K curve that takes into account existence of the knee close to the threshold value of the stress intensity factor. The paper shows important differences between different crack propagation rate descriptions on the residual fatigue lifetime estimation of the railway axles. Results obtained can be used for safer design and operation of the railway axles.
Trvalý link: http://hdl.handle.net/11104/0251233