TY - JOUR A1 - Munzke, Dorit A1 - Kraus, David A1 - Eisermann, René A1 - Kübler, Stefan A1 - Schukar, Marcus A1 - Nagel, Lukas A1 - Hickmann, Stefan A1 - Trappe, Volker T1 - Distributed fiber-optic strain sensing with millimeter spatial resolution for the structural health monitoring of multiaxial loaded GFRP tube specimens N2 - Due to their high strength-to-weight ratio and excellent fatigue resistance, glass fiber reinforced polymers (GFRP) are used as a construction material in a variety of applications including composite high-pressure gas storage vessels. Thus, an early damage detection of the composite material is of great importance. Material degradation can be determined via measuring the distributed strain profile of the GFRP structures. In this article, swept wavelength interferometry based distributed strain sensing (DSS) was applied for structural health monitoring of internal pressure loaded GFRP tube specimens. Measured strain profiles were compared to theoretical calculation considering Classical Lamination Theory. Reliable strain measurements with millimeter resolution were executed even at elongations of up to 3% in the radial direction caused by high internal pressure load. Material fatigue was localized by damaged-induced strain changes during operation, and detected already at 40% of burst pressure. KW - GFRP KW - Swept wavelength interferometry KW - Distributed fiber optic sensing KW - Material degradation KW - Structural health monitoring PY - 2019 DO - https://doi.org/10.1016/j.polymertesting.2019.106085 SN - 0142-9418 VL - 80 SP - 106085 PB - Elsevier Ltd. AN - OPUS4-48950 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Müller, Alexander A1 - Trappe, Volker A1 - Hickmann, Stefan A1 - Ortwein, H.-P ED - Christ, Hans-Jürgen T1 - Investigation of the infinite life of fibre-reinforced plastics using X-ray refraction topography for the in-situ, nondestructive evaluation of micro-structural degradation processes during cyclic fatigue loading N2 - The described investigation of carbon-fibre-reinforced plastics (CFRP) documents that damage evolution can be observed by means of X-ray refractography. Comparative investigations with synchrotron technique on CFRP and grey-scale analysis on glass fibre-reinforced-plastics (GFRP) confirm these results. Moreover it was found that the fracture mechanical properties of the matrix system influence damage nucleation and propagation in the laminate during static and fatigue loads. Single-step fatigue tests were carried out on Laminates with RIM135 and LY556 matrix systems made from non-crimped fabric (NCF) or twill weave in different fibre orientations. The damage to the LY556 laminates was characterized by laminate cracks growing rapidly over the whole specimen width, whereas the damage on the RIM135 laminates was characterized by an earlier onset of micro-cracking followed by laminate cracks. The specimens were fatigued up to 108 (very high cycle fatigue (VHCF) regime) load cycles. S-N-curves of damage initiation were drawn and boundaries were identified for endurance within the VHCF regime. A phenomenology based model focusing on matrix stress was applied to reproduce the first inter-fibre failure (IFF) under static and fatigue loads. KW - Carbon fibre-reinforced-plastics KW - Fatigue KW - Damage evolution KW - X-ray refractography KW - Very high cycle fatigue PY - 2018 SN - 978-3-658-24531-3 DO - https://doi.org/10.1007/978-3-658-24531-3 VL - 2018 SP - 417 EP - 439 PB - Springer Spektrum CY - Wiesbaden ET - 1. Auflage AN - OPUS4-50096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker A1 - Ortwein, Hans-Peter A1 - Hickmann, Stefan T1 - Infinite life of CFRP evaluated nondestructively with X-ray-refraction topography N2 - CFRP are more and more used in modern civil aircrafts hence the whole fuselage is made of this material (B787; A350). Due to strict certification Standards finally the normal in-service loading gives a low stress level compared to the static and even the fatigue strength of the material. Hence CFRP are assumed to have an infinite life. To evaluate this assumption, fatigue tests on CFRP-specimens were performed up to 108 load cycles. The first inter-fiber failure was evaluated non-destructively by the fatigue tests accompanying X-ray-refraction topography altemately and in-situ mechanical loading. The basic idea of the investigation is represented in fig. 1. At low load levels it could not be assumed the total failure of the samples. Hence accompanying non-destructive testing (NDT) is mandatory to get information about the damage state of the material. T2 - ICCM19 - 19th International conference on composite materials CY - Montreal, Canada DA - 28.07.2013 KW - Carbon fibre reinforced plastics (CFRP) KW - Very high cycle fatigue (VHCF) KW - Non-destructive testing (NDT) KW - X-ray refraction KW - Damage mechanics PY - 2013 SP - 1 EP - 8 AN - OPUS4-31169 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Trappe, Volker A1 - Hickmann, Stefan A1 - Sturm, Heinz T1 - Bestimmung des Zwischenfaserbruchversagens in textilverstärktem Glasfaserkunststoff mittels der Röntgenrefrationstopografie N2 - Moderne Leichtbaustrukturen (Luftfahrt, Eisenbahn, Automotive) aus Faserverbundwerkstoffen (FVW) sind hohen mechanischen und klimatischen Beanspruchungen ausgesetzt. Aussagen über die Lebensdauer und Funktionssicherheit der FVW-Bauteile können eher aus Untersuchungen der mikromechanischen Eigenschaften gewonnen werden als aus der globalen Festigkeit. Die Röntgenrefraktionstopografie ist ein Verfahren zur zerstörungsfreien Bestimmung von inneren Oberflächen in Werkstoffen. Angewendet auf FVW lassen sich Aussagen über die Faserorientierungen, die Fertigungsqualität sowie über Faser-Matrix-Ablösungen und Matrixrisse infolge mechanischer Beanspruchung gewinnen. Nachfolgend wird ein neues Verfahren zur Bestimmung des Zwischenfaserbruchversagens am komplexen Laminat vorgestellt. Hierbei wird das Röntgenrefraktionsverfahren "online“ bei Zug-Belastung der Probe angewendet. KW - Zerstörungsfreie Prüfung KW - Röntgenstreuung KW - Faserverbundwerkstoffe KW - Mikrorissbildung KW - Glasfaserverstärkter Kunststoff PY - 2008 SN - 0025-5300 VL - 50 IS - 10 SP - 615 EP - 622 PB - Hanser CY - München AN - OPUS4-18282 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grasse, Fabian A1 - Trappe, Volker A1 - Hickmann, Stefan A1 - Meister, O. T1 - Lifetime assessment for GFRP-gliders using a representative substructure N2 - In a research project fatigue tests on two identical wing sections that are used as representative substitute components were performed to estimate lifetime enhancement of light-weight aircraft such as general aviation gliders. Single step fatigue tests at limit load on one component were compared with spectrum loading on the other. A characteristic damage behaviour was observed. Local buckling due to high shear loading of the sandwich core of the wing shell causes the main damage. Even though an intentionally high load level was chosen no increase of micro-cracking could be detected. Additionally no delamination effects in laminates or bondings were observed except the skin-core delamination which causes the buckling effect in the wing shell due to fatigue loading. Finally the concept of using representative substructures and accompanying specimen tests is an effective approach for in-service loading investigations and could also be applied to research on wind turbine blades. KW - Glass fibre reinforced plastics (GFRP) KW - Grey scale value analysis KW - X-ray-refraction KW - Non-destructive testing (NDT) KW - Fatigue tests PY - 2010 DO - https://doi.org/10.1016/j.ijfatigue.2009.02.003 SN - 0142-1123 VL - 32 IS - 1 SP - 94 EP - 99 PB - Elsevier CY - Oxford AN - OPUS4-20498 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ortwein, Hans-Peter A1 - Trappe, Volker A1 - Bohse, Jürgen A1 - Hickmann, Stefan ED - Grellmann, W. T1 - In-Situ-Messung der Matrixschädigung in kohlenstofffaserverstärktem Kunststoff unter uni- und biaxialer Zugbelastung N2 - Die Restlebensdauerabschätzung von Faserkunststoffverbunden ist ein ungelöstes Problem. Die Beobachtung der Matrixschädigung ist dabei ein vielversprechender Ansatz zur Bewertung des Schädigungszustandes insgesamt. Unter kombinierter Beobachtung mit Röntgenrefraktionsmessungen und Schallemissionsmessung wurden uni- und biaxiale Lasten statisch und zyklisch auf Kohlenstofffaserepoxidharz-Proben aufgebracht. Die uniaxiale Belastung erfolgt mittels einer eigenentwickelten Kompaktprüfmaschine direkt während der Röntgenrefraktions- und Schallemissionsmessung in der Röntgenkammer. Die biaxiale Belastung wird an Modelldruckbehältern ebenfalls mit Schallemissionsmessung durchgeführt. Hier wird der Modelldruckbehälter mit dem Röntgenrefraktionsverfahren periodisch inspiziert. T2 - DVM-Tagung Werkstoffprüfung 2011 - Neue Entwicklungen in der Werkstoffprüfung - Herausforderungen an die Kennwertermittlung CY - Berlin, Germany DA - 01.12.2011 KW - Druckbehälterprüfung KW - CFK KW - Schallemissionsmessung KW - Röntgenrefraktionsmessung KW - Matrixschädigung KW - Faserkunststoffverbund KW - Druckbehälter PY - 2011 SN - 978-3-9814516-1-0 SN - 1861-8154 N1 - Serientitel: DVM-Bericht – Series title: DVM-Bericht IS - 643 SP - 161 EP - 166 AN - OPUS4-24931 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grasse, Fabian A1 - Trappe, Volker A1 - Hickmann, Stefan ED - Grellmann, W. T1 - Zustandsüberwachung von Rotorblättern - Konzeptstudie mittels Bauteilkomponentenversuch T2 - DVM-Tagung Werkstoffprüfung 2011 - Neue Entwicklungen in der Werkstoffprüfung - Herausforderungen an die Kennwertermittlung CY - Berlin, Deutschland DA - 2011-12-01 KW - Rotorblatt KW - Faserverbundwerkstoffe KW - Modalanalyse KW - Zustandsüberwachung KW - Faser-Bragg-Gitter-Sensoren KW - Rotor blade KW - Fibre reinforced plastics KW - Modal analysis KW - Condition monitoring KW - Fibre bragg grating sensors PY - 2011 SN - 978-3-9814516-1-0 SN - 1861-8154 N1 - Serientitel: DVM-Bericht – Series title: DVM-Bericht IS - 643 SP - 167 EP - 172 AN - OPUS4-25078 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Günzel, Stephan A1 - Hickmann, Stefan A1 - Wittemeyer, Christian A1 - Trappe, Volker T1 - Effects of fiber orientation and moisture on the crack growth in short glass fiber reinforced polyamide N2 - Short glass fiber reinforced polyamides are increasingly used in automotive applications. Concepts and models are needed, which enable the prediction of the structural durability. The fiber orientation and the content of moisture have a major influence on the fracture mechanical properties and on the damage mechanisms. The complex crack growth behavior was investigated and described in an empirical model. PY - 2012 DO - https://doi.org/10.1002/adem.201100337 SN - 1438-1656 VL - 14 IS - 10 SP - 867 EP - 872 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-26938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisermann, René A1 - Schukar, Marcus A1 - Nagel, Lukas A1 - Hickmann, Stefan A1 - Munzke, Dorit A1 - Trappe, Volker T1 - Characterising the material degradation of inner pressure-loaded GFRP-tube specimens using distributed strain sensing N2 - Glass-fibre-reinforced plastics (GFRP) are commonly used for the construction of pressure vessels and tanks for example in automotive and aerospace industries. Especially for pressure vessels used for the storage of natural gas or hydrogen with operation pressures up to 700 bar, an early material fatigue detection is of great interest. Measuring the distributed strain profile of GFRP structures helps to understand and detect material fatigue. In this article, we demonstrate the great potential of swept wavelength interferometry (SWI) based distributed strain sensing for the monitoring of pressure vessels made from GFRP. A resin transfer molding (RTM) process was used to manufacture GFRP-tube specimens. Commercial optical fibres with polyimid coating were glued to the surface externally in circumferential and axial direction. A cyclic load of up to 150 bar was applied to the samples using a servo-hydraulic test bench. Comparing the loaded and unloaded test conditions, we determined up to 2 % elongation in circumferential direction. We demonstrate reliable distributed strain measurements with sub-centimetre spatial resolution. By monitoring these high-resolution strain profiles, we were able to detect local material degradation that manifested itself as localized strain changes. Crucially, the material Degradation could be detected already after 75 % of dat the fatigue life before a crack appeared that led to leakage. T2 - Sensoren und Messsysteme - 19. ITG/GMA-Fachtagung CY - Nürnberg, Germany DA - 26.06.2018 KW - Distributed fibre optic sensors KW - Optical backscatter reflectometry KW - Swept wavelength interferometry (SWI) KW - Structural health monitoring (SHM) KW - Composite structures KW - Optical fibre PY - 2018 UR - https://ieeexplore.ieee.org/document/8436172/ SN - 978-3-8007-4683-5 SP - 239 EP - 242 PB - VDE VERLAG GMBH CY - Berlin AN - OPUS4-45887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker A1 - Nielow, D. A1 - Hickmann, Stefan A1 - Kupsch, Andreas A1 - Gaal, Mate A1 - Redmer, Bernhard A1 - Krankenhagen, Rainer T1 - Sandwich-Schalenstrukturen in situ charakterisiert mit Thermographie und Felddehnungsmessungen N2 - An der BAM wurde ein Schalenprüfstand entwickelt, mit dem typische Sandwichschalenstrukturen unter simulierter Betriebsbeanspruchung belastet werden können. Im mechanischen Ermüdungsversuch wurden in situ die Entstehung von Schäden in Schalenprüfkörpern mit Test-Imperfektionen mittels der passiven Thermographie und Felddehnungsmessungen verfolgt. Damit konnten der Zeitpunkt, der Schadensursprung und der Schadensfortschritt zerstörungsfrei bestimmt werden. Zudem wurden vergleichend Schalenprüfkörper mit Luftultraschall und der Röntgen-Laminographie untersucht. Im Rahmen eines BMWi-Forschungsvorhabens wurden die Schädigungsmechanismen evaluiert und Empfehlungen für die Praxis der Fertigung von Rotorblättern abgeleitet. In diesem Beitrag wird sich auf die Darstellung der ZfP-Verfahren und der ZfP-Ergebnisse konzentriert. T2 - DGZfP-Jahrestagung 2018 CY - Leipzig, Germany DA - 07.05.2018 KW - Windkraft KW - Rotorblatt KW - Schalenprüfstand KW - Thermographie KW - Laminographie KW - Luftultraschall PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-469395 VL - 166 SP - 1 EP - 11 AN - OPUS4-46939 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -