TY - JOUR A1 - Zerbst, Uwe A1 - Beretta, S. A1 - Köhler, G. A1 - Lawton, A. A1 - Vormwald, M. A1 - Beier, H.T. A1 - Klinger, Christian A1 - Cerný, I. A1 - Rudlin, J. A1 - Heckel, Thomas A1 - Klingbeil, Dietmar T1 - Safe life and damage tolerance aspects of railway axles - A review N2 - The paper gives an overview on safe life and damage tolerance methods applied to railway axles. It describes failure scenarios due to fatigue crack initiation and propagation. Besides common aspects of design, specific features such as corrosion and impact damage from flying ballast are discussed which may reduce the fatigue strength of axles during service. Potential effects of non-metallic inclusions from the steel manufacturing process are addressed in the context of the very high number of loading cycles railway axles are designed for. With respect to damage tolerance general lines of fracture mechanics residual lifetime analyses are introduced. More specific discussion is provided on aspects such as the threshold value of fatigue crack propagation and reliability aspects of non-destructive inspection. KW - Railway axle KW - Safe life design KW - Damage tolerance KW - Fatigue strength KW - Fatigue crack propagation KW - Inspection intervals PY - 2013 U6 - https://doi.org/10.1016/j.engfracmech.2012.09.029 SN - 0013-7944 SN - 1873-7315 VL - 98 SP - 214 EP - 271 PB - Elsevier Science CY - Kidlington AN - OPUS4-27779 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Klinger, Christian A1 - Klingbeil, Dietmar T1 - Structural assessment of railway axles - A critical review N2 - The safety assessment of railway axles is based on a two-stage approach: fatigue strength design and regular inspections which, in terms of a general safety philosophy refer to safe-life and damage tolerance concepts. Starting with a recent failure case, a broken axle of a German high speed train, a discussion is presented on issues of both safety levels. These include ideas for finite life design, the treatment of in-service effects on the fatigue strength due to flying ballast damage and corrosion pits, the effect of corrosion on fatigue crack initiation and propagation, potential effects of non-metallic inclusions in steels, the way to detect them by quality control measures and reliability aspects of non-destructive testing with respect to the detection of fatigue cracks. Proposals are made how the safety level could be further improved. KW - Railway axles KW - Safe life design KW - Damage tolerance design KW - Non-destructive testing KW - Flying ballast impact KW - Corrosion KW - Non-metallic inclusions PY - 2013 UR - http://www.sciencedirect.com/science/article/pii/S1350630712002531 SN - 1350-6307 SN - 1873-1961 VL - 35 IS - Special issue on ICEFA V- Part 1 SP - 54 EP - 65 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-29715 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Eufinger, J. A1 - Bruder, T. T1 - Bruchmechanisches Modell zur Ermittlung der Schwingfestigkeit von geschweißten und nichtgeschweißten Proben N2 - Ermüdungsrisse gehen in technischen Materialien in der Regel von Werkstoffdefekten auf oder nahe der Oberfläche aus. Bei Schweißverbindungen können Schweißnahtdefekte, z. B. oberflächennahe Schlackeneinschlüsse die Risseinleitungsphase erheblich verkürzen, so dass der Hauptteil der Lebensdauer auf die Phase der Kurzriss- und zu geringerem Anteil auf die Langrissausbreitung entfällt. Bei nichtgeschweißten Bauteilen aus technischen Werkstoffen starten Ermüdungsrisse häufig an Einschlüssen, oberflächennahen Poren oder anderen Ungänzen. Einerseits ermöglicht dies prinzipiell die Anwendung bruchmechanischer Methoden zur Ermittlung der Schwingfestigkeit, andererseits müssen die Methoden in der Lage sein, spezielle Aspekte des Kurzrisswachstums wie den graduellen Aufbau des Rissschließeffekts und die lokale Rissspitzenplastizität zu erfassen. Im Beitrag werden ein geeignetes analytisches Modell sowie erste Validierungen an Proben aus verschiedenen Aluminiumlegierungen vorgestellt. Der abschließende Teil des Beitrags geht auf Besonderheiten von Schweißverbindungen (Schweißnahtdefekte, Eigenspannungen etc.) im Kontext des vorgestellten Modells ein. Eine Erweiterung des Modells für Schweißverbindungen aus Stahl wird im Rahmen eines kürzlich gestarteten DFG-AiF-Clusterprojekts erfolgen. PY - 2013 UR - http://www.hanser-elibrary.com/doi/pdf/10.3139/120.110465 U6 - https://doi.org/10.3139/120.110465 SN - 0025-5300 VL - 55 IS - 7-8 SP - 511 EP - 519 PB - Hanser CY - München AN - OPUS4-30323 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Kiyak, Yusuf A1 - Madia, Mauro A1 - Burgold, Andreas A1 - Riedel, Gernot T1 - Reference loads for plates with semi-elliptical surface cracks subjected to tension and bending for application within R6 type flaw assessment N2 - Two of the authors of the present paper proposed a definition of a reference load F0 which can be used as an alternative option to the common limit load for cases where the definition of the latter might be problematic in the frame of flaw assessment procedures such as R6, BS 7910, SINTAP or FITNET. The reference load is defined as that load at which the ligament yielding parameter Lr approaches one. F0, in general, varies along the crack front. It has to be obtained by finite element analyses but the results can be approximated by analytical expressions. In a previous study of the authors such a solution was presented for tension loaded plates with semi-elliptical surface cracks. In the present paper it is extended to pure bending and to combined bending and tension. KW - Flaw assessment KW - R6 procedure KW - BS 7910 KW - SINTAP KW - FITNET KW - Limit load KW - Reference load PY - 2013 U6 - https://doi.org/10.1016/j.engfracmech.2012.11.017 SN - 0013-7944 SN - 1873-7315 VL - 99 SP - 132 EP - 140 PB - Elsevier Science CY - Kidlington AN - OPUS4-30416 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -