TY - CONF A1 - Maierhofer, Christiane A1 - Krankenhagen, Rainer A1 - Röllig, Mathias A1 - Riemer, Stefanie A1 - Gower, M. A1 - Baker, G. A1 - Lodeiro, M. A1 - Knazovicka, L. A1 - Blahut, A. A1 - Monte, C. A1 - Adibekyan, A. ED - Gutschwager, B. T1 - Characterisation of artificial and natural defects in fibre reinforced plastics designed for energy applications using active thermography N2 - Amongst various other NDT methods, within the EMRP-project ‘VITCEA’ active thermography is validated for testing of CFRP and GFRP structures constructed for energy application. In this contribution, the optical and thermal properties of CFRP and GFRP reference defect artefact (RDA) and natural defects artefact (NDA) test specimens are characterized. Different excitation techniques and techniques for data analysis are compared for optimizing the number of detected defects. T2 - 19th World Conference on Non-destructive Testing (WCNDT) CY - Munich, Germany DA - 13.06.2016 KW - Active thermography KW - CFRP KW - GFRP KW - Artificial and natural defects PY - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-370207 UR - http://www.ndt.net/article/wcndt2016/papers/we2i4.pdf SN - 978-3-940283-78-8 VL - BB 158 SP - Paper we2i4, 1 EP - 9 PB - DGZfP CY - Berlin AN - OPUS4-37020 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maierhofer, Christiane A1 - Krankenhagen, Rainer A1 - Röllig, Mathias A1 - Rehmer, Birgit A1 - Gower, M. A1 - Baker, G. A1 - Lodeiro, M. A1 - Aktas, A. A1 - Knaszovicka, L. A1 - Blahut, A. A1 - Monte, C. A1 - Adibekyan, A. A1 - Gutschwager, B. T1 - Characterisation of artificial defects in CFRP and GFRP sheets designed for energy applications using active thermography N2 - The increased use of fibre-reinforced plastic (FRP) composites for improved efficiency and reliability in energy related applications e.g. wind and marine turbine blades, nacelles, oil and gas flexible risers, also increases the demand for innovative non-destructive testing technologies. Thus, in order to achieve increased acceptance of suited and optimized non-destructive testing (NDT) methods in industry, the European Metrology Research Programme (EMRP) project ENG57 Validated Inspection Techniques for Composites in Energy Applications (VITCEA) deals with the development and validation of innovative NDT technologies. In this contribution, results concerning thermographic investigations at test specimens during tensile loading and active thermography testing after tensile loading are presented. Additionally, the determination of the optical properties (relative transmittance and directional spectral emissivity) of CFRP and GFRP test specimens is described. T2 - Conference QIRT 2016 CY - Gdansk, Poland DA - 04.07.2016 KW - Active thermography KW - CFRP KW - GFRP KW - Validation of methods PY - 2016 UR - http://qirt.gel.ulaval.ca/archives/qirt2016/papers/076.pdf U6 - https://doi.org/10.21611/qirt.2016.076 SN - 2371-4085 SP - Paper 076, 527 EP - 536 CY - Quebec, Canada AN - OPUS4-37512 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krankenhagen, Rainer A1 - Maierhofer, Christiane A1 - Heckel, Thomas A1 - Brackrock, Daniel A1 - Gower, M. A1 - Lodeiro, M. A1 - Baker, G. T1 - Quantitative comparison of different non-destructive techniques for the detection of artificial defects in GFRP N2 - In order to test their suitability different non-destructive methods were performed to inspect a GFRP plate with artificial defects. These defects were manufactured by means of thin PTFE sheets inserted between two plies in three different depth. The inspection methods were microwave reflection, flash thermography and phased array ultrasonics, all applied to the same specimen. Selected results are shown for all methods demonstrating opportunities and limits of the particular inspection methods. The achieved detection limits and further application aspects are compared directly to provide a useful information for the planning of inspection tasks. T2 - ECNDT CY - Gothenburg, Sweden DA - 11.06.2018 KW - Fiber resisted polymers KW - Non-destructive testing KW - Thermographic testing KW - Ultrasonic testing PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-453728 SP - ECNDT-0247-2018 AN - OPUS4-45372 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maierhofer, Christiane A1 - Röllig, Mathias A1 - Gower, M. A1 - Lodeiro, M. A1 - Baker, G. A1 - Monte, C. A1 - Adibekyan, A. A1 - Gutschwager, B. A1 - Knazowicka, L. A1 - Blahut, A. T1 - Evaluation of different techniques of active thermography for quantification of artificial defects in fiber-reinforced composites using thermal and phase contrast data analysis N2 - For assuring the safety and reliability of components and constructions in energy applications made of fiber-reinforced polymers (e.g., blades of wind turbines and tidal power plants, engine chassis, flexible oil and gas pipelines) innovative non-destructive testing methods are required. Within the European Project VITCEA complementary methods (shearography, microwave, ultrasonics and thermography) have been further developed and validated. Together with partners from the industry, test specimens have been constructed and selected on-site containing different artificial and natural defect artefacts. As base materials, carbon and glass fibers in different orientations and layering embedded in different matrix materials (epoxy, polyamide) have been considered. In this contribution, the validation of flash and lock-in thermography to these testing problems is presented. Data analysis is based on thermal contrasts and phase evaluation techniques. Experimental data are compared to analytical and numerical models. Among others, the influence of two different types of artificial defects (flat bottom holes and delaminations) with varying diameters and depths and of two different materials (CFRP and GFRP) with unidirectional and quasi-isotropic fiber alignment is discussed. KW - Active thermography KW - CFRP KW - GFRP KW - Delaminations KW - Flash excitation KW - Lock-in excitation PY - 2018 U6 - https://doi.org/10.1007/s10765-018-2378-z SN - 0195-928X SN - 1572-9567 VL - 39 IS - 5 SP - Article 61, 1 EP - 37 PB - Springer AN - OPUS4-44687 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maierhofer, Christiane A1 - Krankenhagen, Rainer A1 - Röllig, Mathias A1 - Unnikrishnakurup, Sreedhar A1 - Monte, C. A1 - Adibekyan, A. A1 - Gutschwager, B. A1 - Knazowicka, L. A1 - Blahut, A. A1 - Gower, M. A1 - Lodeiro, M. A1 - Baker, G. A1 - Aktas, A. T1 - Einfluss thermischer und optischer Materialeigenschaften auf die Charakterisierung von Fehlstellen in Faserverbundwerkstoffen mit aktiven Thermografieverfahren T1 - Influence of thermal and optical material properties on the characterization of defects in fiber reinforced composites with active thermography methods N2 - In diesem Beitrag werden zerstörungsfreie Untersuchungen mittels aktiver Thermografie an Probekörpern aus CFK und GFK mit unterschiedlichen künstlichen Fehlstellen vorgestellt. Dabei wird die zeitliche und örtliche Temperaturverteilung nach der Erwärmung mit Blitzlampen oder mit einem Infrarot-Strahler mit einer Infrarot-Kamera erfasst. Zur späteren Rekonstruktion der Messdaten wurde ein numerisches Modell entwickelt. Dazu war die Bestimmung der thermophysikalischen und optischen Materialeigenschaften erforderlich, was in diesem Beitrag ebenfalls beschrieben wird. Die Ergebnisse der numerischen Modellierung werden mit den experimentellen Untersuchungen der aktiven Thermografie verglichen. Weiterhin werden die experimentellen Untersuchungen hinsichtlich der beiden Materialsysteme CFK und GFK und unter Berücksichtigung der Teiltransparenz des GFK-Materials sowie der unterschiedlichen Anregungsquellen bewertet. N2 - This paper presents results of the non-destructive evaluation of CFRP and GFRP test specimens with various artificial defects using active thermography. After heating the specimens with flash lamps or with an infrared radiator, the temporal and spatial resolved temperature distribution is recorded with an infrared camera. For the reconstruction of the experimental data, a numerical model was developed. For the numerical simulations, the thermal and optical material parameters had to be determined, which is described in this contribution as well. The results of numerical modelling are compared to experimental data of active thermography. Additionally, the experimental results are assessed related to the two materials CFRP and GFRP by considering the partial transmissivity of the GFRP material, and to the different excitation sources. T2 - Temperatur 2017 CY - Berlin, Germany DA - 17.05.2017 KW - Zerstörungsfreie Prüfung KW - Aktive Thermografie KW - Faserverbundwerkstoffe (CFK, GFK) KW - Numerische Simulation PY - 2017 U6 - https://doi.org/10.1515/teme-2017-0078 SN - 0171-8096 SN - 2196-7113 VL - 85 IS - 1 SP - 13 EP - 27 PB - DE GRUYTER CY - Oldenburg AN - OPUS4-42395 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maierhofer, Christiane A1 - Krankenhagen, Rainer A1 - Röllig, Mathias A1 - Unnikrishnakurup, Sreedhar A1 - Monte, C. A1 - Adibekyan, A. A1 - Gutschwager, B. A1 - Knazowicka, L. A1 - Blahut, A. A1 - Gower, M. A1 - Lodeiro, M. A1 - Baker, G. A1 - Aktas, A. T1 - Einfluss thermischer und optischer Materialeigenschaften auf die Charakterisierung von Fehlstellen in Faserverbundwerkstoffen mit aktiven Thermografieverfahren N2 - In diesem Beitrag werden zerstörungsfreie Untersuchungen mittels aktiver Thermografie an Probekörpern aus CFK und GFK mit unterschiedlichen künstlichen Fehlstellen vorgestellt. Dabei wird die zeitliche und örtliche Temperaturverteilung nach Erwärmung mit Blitzlampen oder mit einem Infrarot-Strahler mit einer Infrarot-Kamera erfasst. Zur Rekonstruktion der Messdaten wurde ein numerisches Modell entwickelt. Dazu war die Bestimmung der thermischen und optischen Materialeigenschaften erforderlich. N2 - This paper presents results of the non-destructive evaluation of CFRP and GFRP test specimens with various artificial defects using active thermography. After heating the samples with flash lamps or with an infrared radiator, the temporal and spatial resolved temperature distribution is recorded with an infrared camera. For the reconstruction of the experimental data, a numerical model was developed. For the numerical simulations, the thermal and optical material parameters had to be determined. T2 - Temperatur 2017 CY - Berlin, Germany DA - 17.05.2017 KW - CFK KW - GFK KW - aktive Thermografie KW - numerische Simulation KW - Emissivität PY - 2017 SN - 978-3-944659-04-6 SP - 15 EP - 20 AN - OPUS4-41088 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maierhofer, Christiane A1 - Krankenhagen, Rainer A1 - Röllig, Mathias A1 - Hosseini, Seyed A1 - Heckel, Thomas A1 - Gaal, Mate A1 - Schadow, Florian A1 - Brackrock, Daniel A1 - Gower, M. A1 - Lodeiro, M. A1 - Baker, G. T1 - Quantitative Bewertung künstlicher und natürlicher Fehler in Faserverbundwerkstoffen mit aktiver Thermografie und Ultraschall N2 - Im EMRP-Projekt VITCEA werden komplementäre ZFP-Verfahren zur Prüfung von Faserverbundwerkstoffen weiterentwickelt und validiert. In diesem Beitrag werden Ergebnisse verschiedener Techniken der aktiven Thermografie und des Ultraschalls vorgestellt. Die Nachweisempfindlichkeiten bezüglich künstlicher und natürlicher Fehler mit unterschiedlichen lateralen Ausdehnungen und in verschiedenen Tiefen werden miteinander verglichen. T2 - DGZfP Jahrestagung 2017 CY - Koblenz, Germany DA - 22.05.2017 KW - CFK KW - GFK KW - Aktive Thermografie KW - Phased Array Ultraschall KW - Luftultraschall PY - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-410902 SN - 978-3-940283-85-6 VL - BB 162 SP - Di1B1, 1 EP - Di1B1, 8 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung e. V. AN - OPUS4-41090 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maierhofer, Christiane A1 - Krankenhagen, Rainer A1 - Röllig, Mathias A1 - Rehmer, Birgit A1 - Gower, M. A1 - Baker, G. A1 - Lodeiro, M. A1 - Aktas, A. A1 - Monte, C. A1 - Adibekyan, A. A1 - Gutschwager, B. T1 - Defect characterisation of tensile loaded CFRP and GFRP laminates used in energy applications by means of infrared thermography N2 - The increased use of fibre reinforced plastic (FRP) composites for improved efficiency and reliability in energy related applications, e.g. wind and marine turbine blades, nacelles, oil and gas flexible risers, also increases the demand for innovative non-destructive testing technologies. In this contribution, results concerning the characterisation of CFRP and GFRP during and after quasi-static tensile loading are presented. It includes the measurement of optical properties in the infrared spectral range, tensile loading tests with the observation of the temperature distribution at one or both sides of the specimens using an infrared camera for the preparation and monitoring of intended natural defects, and active thermography inspections after tensile loading. It is shown that the defect preparation was successful. Thermographic monitoring during and active thermography testing after tensile loading enable the detection of the lateral extend of the generated defects. Differences between CFRP and GFRP materials are discussed. KW - Tensile loading KW - Fibre reinforced composites KW - Active and passive thermography KW - Emissivity PY - 2017 U6 - https://doi.org/10.1080/17686733.2017.1334312 SN - 1768-6733 SN - 2116-7176 VL - 15 IS - 1 SP - 17 EP - 36 PB - Taylor and Francis CY - London AN - OPUS4-40968 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -