TY - CONF A1 - Klinger, Christian T1 - Schwingbruch einer Kraftstoffleitung durch Biodiesel? N2 - Schadensteil: PME-Kraftstoffleitung Schadensmechanismus: Reibverschleiß und Schwingbruch Schadensursachen: Nichtbeständigkeit der Elastomereinlage in Befestigungsschelle gegen unplanmäßig ausgetretenen Biodiesel (PME); Schwingungen der Kraftstoffleitungen Schadensablauf: Elastomer versprödet, Schwingungen der Kraftstoffanlage, Reibverschleiß an der Befestigungsschelle, äußerliche oberflächliche Korrosion der Leitung; Schwingbruch der Kraftstoffleitung; Brand am Motor eines BHKWs T2 - 42. VDI-Jahrestagung CY - Würzburg, Germany DA - 29.09.2016 KW - Schwingbruch PY - 2016 VL - 42. VDI-Jahrestagung SP - 109 EP - 119 PB - VDI-Wissensforum GmbH AN - OPUS4-38284 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk A1 - Klinger, Christian T1 - Aufbau einer Wissensbasis zu Bruchflächen und Gefüge in der fraktographischen online-Datenbank N2 - In einer fraktographischen online-Datenbank werden Informationen zum Bruchverhalten von technischen Werkstoffen zusammengetragen. Primäres Ziel ist die kontrollierte Erzeugung von Brüchen und deren anschließende Analyse, aber auch Beispiele aus Schadensfällen werden eingestellt. Die makroskopischen und mikroskopischen Merkmale von Bruchflächen, die Art der Beanspruchung und die dazugehörigen Werkstoffgefüge werden in Datensätzen zusammengefasst, die der interessierten Fachöffentlichkeit zu Verfügung stehen. T2 - Metallographietagung 2016 CY - Berlin, Germany DA - 21.9.2016 KW - Fraktografie KW - Datenbank KW - Bruchverhalten KW - Schadensanalyse PY - 2016 SN - 978-3-88355-412-9 VL - 50 SP - 3 EP - 12 PB - DGM AN - OPUS4-38189 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk A1 - Sonnenburg, Elke A1 - Klinger, Christian T1 - Metallographische Zielpräparation von Ungänzen im Zusammenspiel mit ZfP-Methoden N2 - Oft sind von außen nicht sichtbare „Ungänzen“ im Innern die Ursache für das Versagen von Bauteilen. In manchen Fällen genügt eine herkömmliche metallographische Präparation, um der Schadensursache auf die Spur zu kommen. In anderen Fällen aber sind die Ungänzen zu klein oder ihre Lage zu ungewiss, um sie mit zufälligen Schnitten zu treffen. Zudem würde man durch Fehlversuche das Bauteil zu stark schädigen und so wertvolle Spuren verlieren sowie die weitere Untersuchbarkeit einschränken. In solchen Fällen ist es im wahrsten Sinn des Wortes zielführend, die Ungänzen mit Hilfe eines räumlich abbildenden ZfP-Verfahrens zu lokalisieren und dann mit den erhaltenen Koordinaten eine metallographische Zielpräparation präzise durchzuführen. Als Methoden kommen z.B. Mikro-Computer-Tomographie (µCT) und Tauch-Ultraschall in Frage. Bauteile können kleine elektronische Komponenten sein, aber auch große Bauteile wie Wellen aus Fahrzeugen oder Anlagen. T2 - Metallographietagung 2016 CY - Berlin, Germany DA - 21.09.2016 KW - Metallographie KW - ZfP KW - Schadensanalyse PY - 2016 AN - OPUS4-38190 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Klinger, Christian A1 - Clegg, R. T1 - Fracture mechanics as a tool in failure analysis - Prospects and limitations N2 - Although fatigue crack propagation and fracture cause a large part of failure events in industrial practice, fracture mechanics in failure analysis seems to be still a side issue. Starting from an introduction into important basic questions of failure analysis and fracture mechanics, the authors specify what kind of questions in failure analysis can be effectively solved by fracture mechanics (and which can't). They illustrate their discussion with a number of 13 case studies from the literature. Much more pronounced than in the design stage the benefit of fracture mechanics in failure analysis depends on its accuracy. This is limited by both, intrinsic factors of the method and the availability and quality of the input information. The authors discuss the various aspects and provide the reader with some background information which, as they believe, will be helpful for better understanding the prospects and limitations of fracture mechanics in failure analysis and the conditions of its application. KW - Failure analysis KW - Fracture mechanics KW - Fatigue KW - Root cause KW - Accompanying measures PY - 2015 U6 - https://doi.org/10.1016/j.engfailanal.2015.07.001 SN - 1350-6307 SN - 1873-1961 VL - 55 SP - 376 EP - 410 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-33839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klinger, Christian A1 - Zunkel, Astrid T1 - Folgeschäden durch Versagen von Gummi-Metall-Verbunden T2 - 41. Jahrestagung "Schadensanalyse", VDI-Wissensforum CY - Würzburg DA - 2015-10-01 PY - 2015 AN - OPUS4-34446 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klinger, Christian A1 - Michael, Thomas A1 - Bettge, Dirk T1 - Fatigue cracks in railway bridge hangers due to wind induced vibrations - Failure analysis, measures and remaining service life estimation N2 - Unexpected wind-induced vibrations of the hangers have caused an early fatigue crack on specific steel components and joints of a railway bridge over the Elbe River at Lutherstadt Wittenberg, Germany. During regular periodic inspection a fatigue crack of approximately 240 mm length was found near a butt weld of the longest hanger. The hanger was immediately secured by welded butt straps across the crack. Based on experimental investigations of hanger vibrations additional bracings were added between the hangers to avoid wind-induced vibrations. The weld heat influence zone which was affected by high cyclic stresses was replaced by new material. Nevertheless it was impossible to determine sufficient remaining service life for those remaining bridge components that were exposed to extreme high real load cycles. The grinding of the affected steel surfaces was the key element of the remedial actions. Furthermore, additional fracture mechanic calculations were carried out in order to assess the remaining service life of the welded joints. In this respect, the calculation approach used by Deutsche Bahn AG was compared to further procedures from the mechanical engineering field. These investigations showed that the studied, repaired components have both, bearing and fatigue capacities within the validity of standards. KW - Bridge hangers KW - Wind induced vibrations KW - Undamped structural elements KW - Fatigue crack KW - Remaining service life PY - 2014 U6 - https://doi.org/10.1016/j.engfailanal.2014.02.019 SN - 1350-6307 SN - 1873-1961 VL - 43 IS - Special Issue 'A Tribute to Prof. A. Martens' SP - 232 EP - 252 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-31318 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Klinger, Christian T1 - Anmerkungen zur Auslegung und zum sicheren Betrieb von Radsatzwellen aus der Sicht von Betriebsfestigkeit und Bruchmechanik N2 - Die Sicherheit von Radsatzwellen beruht gegenwärtig auf zwei Säulen: der Schwingfestigkeitsauslegung und periodischen Inspektionen. Ausgehend von einem Schadensfall, der gebrochenen ICE 3-Welle von Köln, 2008, werden ausgewählte Aspekte dieser beiden Säulen diskutiert und Vorschläge zur weiteren Verbesserung gemacht. Diese betreffen u. a. Fragen einer Betriebszeitbegrenzung, Veränderungen der Schwingfestigkeit während des Betriebs infolge von Korrosion und Steinschlag, den Einfluss von Korrosion auf Schwingrissinitiierung und -fortschritt, den potenziellen Einfluss nichtmetallischer Einschlüsse auf die Schwingfestigkeit, die Möglichkeiten, sie im Rahmen der Qualitätssicherung zu detektieren, sowie Fragen der Bruchmechanik und der Zuverlässigkeit zerstörungsfreier Schwingriss-Prüfverfahren im Rahmen eines Konzepts regelmäßiger Inspektionen. KW - Radsatzwellen KW - Schwingfestigkeit KW - Sichere Lebensdauer KW - Schadenstoleranz KW - Zerstörungsfreie Inspektion KW - Korrosion KW - Steinschlag KW - Nichtmetallische Einschlüsse PY - 2014 U6 - https://doi.org/10.3139/120.110593 SN - 0025-5300 VL - 56 IS - 7-8 SP - 528 EP - 534 PB - Hanser CY - München AN - OPUS4-31355 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klingbeil, Dietmar A1 - Klinger, Christian A1 - Kinder, J. A1 - Baer, Wolfram T1 - Investigations for indications of deliberate blasting on the front bulkhead of the ro-ro ferry MV Estonia N2 - The roll-on-roll-off passenger ferry MV ESTONIA sank during the night of 28 September 1994 in the Baltic Sea. In October 2000, divers recovered two palm-sized test pieces from the front bulkhead of the wreck. The investigators analysed these specimens to determine whether there were any indications of deliberate blasting. Since the wreck had been submerged for almost six years, it was clear that chemical traces would not be present on the surfaces of the test pieces. Therefore, the investigators performed comparative tests on shipbuilding steel to find a microstructural criterion that exclusively characterises a blast. The shipyard Jos. L. Meyer, Germany, had built the ESTONIA and supplied shipbuilding steel plates similar to that used for building the vessel in 1979/1980. The comparative tests comprised mechanical tests, shot peening tests and blasting tests using different explosives. Testing demonstrated that blasting always formed twinned ferrite grains in the microstructure over the whole cross-section of each of the 8 mm thick comparative plates. Although one of the original test pieces of the ESTONIA showed deformation twins, this was only confined up to 0.4 mm underneath the surfaces and not spread over the whole cross-section. Comparative shot peening tests produced the very same pattern of subsurface deformation twins. Therefore, the twins detected in the microsection of the test pieces of the ESTONIA wreck traced back to the shot peening process performed by the shipyard in 1979/1980 and not to a deliberate blast. KW - Investigations on parts of a ship wreck KW - Comparative blasting tests KW - Metallographic analyses of shipbuilding steel KW - Derivation of microstructural criteria for blasting KW - Deformation twins PY - 2014 U6 - https://doi.org/10.1016/j.engfailanal.2014.03.016 SN - 1350-6307 SN - 1873-1961 VL - 43 IS - Special Issue 'A Tribute to Prof. A. Martens' SP - 186 EP - 197 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-31291 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bettge, Dirk A1 - Klinger, Christian A1 - Klingbeil, Dietmar A1 - Eberle, Arno T1 - Investigations on the breakdown of a heat recovery steam generator during the initial operation run N2 - Several years ago, in 2003, an industrial heat recovery steam generator in charge of generating process steam in a petrochemical refinery was installed and prepared for initial operation. The steam generator enclosed an evaporator section and a superheater section consisting mainly of bundles of tubes with the longest up to several metres in length. During initial operation test runs severe leakages in the evaporator and superheater modules became noticeable. The test runs were stopped and after disassembly, through-wall cracks in several tube bends were found. BAM was commissioned to carry out the investigations in order to find out the reasons for the failure of the tubes. During on-site inspection a number of relevant damaged components and parts were selected and taken away to the laboratories for detailed inspection. Planned analyses were to comprise metallographic as well as fractographic investigations, mechanical fatigue testing and experimental as well as finite element vibration analyses on specimens and components. Soon, the fracture mechanism was found to be mechanical fatigue due to the fact that the examined fracture surfaces showed the very characteristic beachmarks and colouring patterns. To identify the particular loading and time at which crack initiation and crack propagation took place, experimental and numerical vibration analyses of specific tubes as well as mechanical fatigue tests on tube bends were carried out. Thus it was possible to identify the eigenfrequencies of individual tubes, to estimate the dynamic response as well as the nominal stresses and, hence, experimentally characterise the in-service fatigue strength of the components. Mechanical and thermal comparative tests on tube bends were performed simulating the conditions during the initial test run in order to get crack surfaces comparable to that of the originally damaged components. Thereby it became obvious that the fatigue cracks were initiated by vibrations the tube bundles were exposed to during rail transport from the manufacturer’s site to the place of installation. Based on these results, the damaged components could be repaired or exchanged without modification of the construction, but the rules relating packaging and securing for shipping had to be revised. KW - Steam generator KW - Fatigue failure KW - Vibration analysis KW - Vibrations due to shipping KW - Transport failure KW - Fatigue PY - 2014 U6 - https://doi.org/10.1016/j.engfailanal.2013.12.005 SN - 1350-6307 SN - 1873-1961 VL - 43 IS - Special Issue 'A Tribute to Prof. A. Martens' SP - 253 EP - 270 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-31490 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klinger, Christian A1 - Bohraus, Stefan T1 - 1992 Northeim train crash - A root cause analysis N2 - Shortly after midnight on 15th November 1992, a severe train crash was caused by the break off of a buffer from a tool and gear wagon of a freight train. The buffer fell between the rails, tumbled, and then lifted one axle of a following freight wagon off the rails. Several freight wagons derailed in the station of Northeim, Germany, blocking the adjacent track. A night train travelling on that blocked track was already too close (only 180 m) to stop, despite emergency braking initiated immediately and automatically by the track signalling system. When the night train crashed into the freight wagons, some of its coaches were heavily damaged. Eleven people were killed, and 51 injured, some of them seriously. The task for failure analysts was to find out why the buffer broke off from the front frame of the tool and gear wagon. Therefore, the material of the attachment, the front frame, and the welds were tested. Chemical composition, hardness, and microstructure were allowable. The welds showed imperfections which were determined not to be causal. The fracture surfaces had graded corrosion – which again was not causal – and beach marks that depicted fatigue cracks before final fracture. The cause for the break off was the fact that the front frame had been repaired at this same buffer attachment some years before and that the repair patch used was thinner than the original front frame profile. Additionally, the force characteristics of the buffer showed reduced stroke but increased forces which was due to several friction springs that had been broken for a long time. The buffer forces in service were assessed from standards, literature, and the deformations of the attachment. The in-service stresses at the welds were estimated using FEM analysis. High cyclic stresses at the welds resulted in fatigue cracking and finally break off of the attachment with the buffer. KW - Buffer break off KW - Northeim train crash (Germany) KW - Friction spring fatigue fractures KW - Lamellar tearing KW - Disastrous coaction of events PY - 2014 U6 - https://doi.org/10.1016/j.engfailanal.2013.10.004 SN - 1350-6307 SN - 1873-1961 VL - 43 IS - Special Issue 'A Tribute to Prof. A. Martens' SP - 171 EP - 185 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-31594 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -