TY - JOUR A1 - Ewert, Uwe A1 - Zscherpel, Uwe A1 - Vogel, Justus A1 - Zhang, F. A1 - Long, N.X. A1 - Nguyen, T.P. T1 - Visibility of Image Quality Indicators (IQI) by Human Observers in Digital Radiography in Dependence on Measured MTFs and Noise Power Spectra N2 - Digital radiographic images were analysed to predict the visibility of image quality indicators (IQI), based on normalized noise power spectra (NNPP) and modulation transfer function (MTF) measurements. The fixed pattern noise of some digital detectors result in different noise spectra, which influence the visibility of different IQIs, depending on the hole diameter. Studies, based on measurement of basic spatial resolution and contrast to noise ratio were performed together with presampled MTF measurements and the NNPS in dependence on the spatial frequency. Plate hole IQIs, step hole IQIs, and equivalent penetrameter sensitivity (EPS) IQIs based on ASTM E 746 were measured to verify the influence of the different parameters. Modelling of digital images was used to verify the applied numeric tools. A study has been performed for imaging plates and digital detector arrays to analyse differences. Formulas for the prediction of the visibility functions for hole type IQIs are derived. In consequence the standards for characterization and classification of computed radiography (ASTM E 2446) and radiography with DDAs (ASTM E 2597) need to be revised. T2 - 12th ECNDT 2018 CY - Gothenburg, Sweden DA - 11.06.2018 KW - Image evaluation KW - Computed radiography (CR) KW - Digital Detector Array (DDA) KW - Detail detection PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-473486 UR - www.ndt.net/?id=22967 SN - 1435-4934 VL - 23 IS - 8 SP - 1 EP - 7 PB - NDT.net CY - Kirchwald AN - OPUS4-47348 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ewert, Uwe A1 - Zscherpel, Uwe A1 - Zhang, F. A1 - Long, N.X. A1 - Phong, N. T1 - Essentielle Parameter zur numerischen Abschätzung der Sichtbarkeit von Bildgüteprüfkörpern in der digitalen Radiographie N2 - Die Voraussetzungen für die Vorhersage der Sichtbarkeit von Bildgüteprüfkörpern (BPK) wurden seit Beginn der kommerziellen Anwendung der technischen Radiographie diskutiert und in diversen nationalen und internationalen Standards festgeschrieben. Diese Fragen werden nach Einführung der digitalen Radiographie und der CT wieder neu diskutiert. Draht BPKs wurden in Deutschland seit 1935 (DIN 1915: 1935) und später in den meisten europäischen Ländern benutzt. In den USA und Frankreich wurden vorzugsweise BPKs mit Löchern verwendet (ASTM E 1025 seit 1984 oder E 1742 seit 1992 bzw. die Vorgängernorm MIL STD-543 seit 1962). Jetzt werden auch die Umrechnungsnormen zur Erkennbarkeit von Draht zu Loch-BPKs in Frage gestellt. ISO 19232-3, der französische RCCM-Kode einerseits und ASTM E 747 und ASME BPVC Section V Tab. T-276 andererseits unterscheiden sich erheblich bei den Anforderungen im Bereich hoher Wandstärken (Hochenergieradiographie). Untersuchungen dazu werden vorgestellt. Mit Einführung der digitalen Detektoren ändern sich auch die Rauschspektren. Durch die Herstellung werden insbesondere bei Speicherfolien "Rauschmuster" eingeprägt, die bei hohen Belichtungsdosen sichtbar werden. Diese veränderten Rauschspektren ergeben auch veränderte Erkennungsparameter für menschliche Bildauswerter. Hierzu wurden an ausgewählten Detektoren MTFs (presampled) und normierte Rauschspektren gemessen. Erweiterte Erkennbarkeits-Formeln zur Vorhersage der Sichtbarkeit von BPKs für Bildauswerter und erste Ergebnisse werden vorgestellt. T2 - DGZfP-Jahrestagung 2018 CY - Leipzig, Germany DA - 07.05.2018 KW - Image quality KW - Computed radiography (CR) KW - Digital Detector Array (DDA), KW - Sichtbarkeit von Anzeigen PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-473496 UR - www.ndt.net/?id=23069 VL - 2018 SP - 1 EP - 14 PB - Deutsche Gesellschaft für zerstörungsfreie Prüfung e.V. (DGZfP) AN - OPUS4-47349 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brückner, B. A1 - Zscherpel, Uwe T1 - Spektroskopie gepulster Röntgenquellen N2 - Spektren von gepulsten Röntgenquellen wie Blitzröhren, Linearbeschleuniger (LINACs) oder Betatrons lassen sich in der Literatur nicht finden. Eine gängige Lehrmeinung ist, dass sich solche Spektren nicht messen lassen. Deshalb wurden in Zusammenarbeit mit der Goethe-Universität Frankfurt und neuester Messtechnik diese Problematik untersucht. Es wurde ein CeBr3-Szintillator-Kristall mit einem klassischen Photoelektronenvervielfacher (PMT) und einer analogen Übertragungskette verwendet, der über Stunden Integrationszeit nur einen sehr geringen Untergrund detektiert. Als kritischter Punkt stellte sich die geeignete Kollimierung von Quelle und Detektor bei möglichst großem Abstand heraus. Zu diesem Zweck wurde das verwendete 7 MeV-Betatron in einen 3t-Bleibunker betrieben, der ein Austrittsloch von 1 mm für die erzeugte Röntgenstrahlung besaß. Der Detektor wurde mit einem Densimet-Zylinder abgeschirmt. Damit konnte die Bedingung für die Spektroskopie gepulster Quellen erreicht werden: pro Puls darf nur 1 Photon den Detektorkristall erreichen, damit ohne Pile-up seine Energie vermessen werden kann. Trotz schnellster Elektronik war es nicht möglich, mehere Photonen pro Röntgenpuls (beim Betatron ca. 1 Mikrosekunde) spektral richtig aufzulösen. Die gemessenen Spektren zeigen die erwartete Form, wie sie z.B. mit aRTist simuliert werden können. T2 - DGZfP-Jahrestagung 2018 CY - Leipzig, Germany DA - 07.05.2018 KW - Spektroskopie KW - Betatron KW - Röntgenblitzröhre PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-473505 SP - 1 EP - 2 PB - Deutsche Gesellschaft für zerstörungsfreie Prüfung e.V. (DGZfP) AN - OPUS4-47350 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Optimum Magnification Factor in Digital Radiography - Selection Criteria and Formulas N2 - The transition from X-ray film to digital detectors in radiography is accompanied by an increase of unsharpness due to the larger inherent digital detector unsharpness in comparison to film. The basic spatial resolution of digital detectors (see EN ISO 17636-2) is used today to describe this unsharpness. The geometrical unsharpness of the radiographic projection of object structures onto the detector plane is determined by the focal spot size of the X-ray tube and the magnification. The focal spot size is measured today (see ASTM E 1165) from pin hole camera exposures or edge unsharpness (see ASTM E 2903). The final image unsharpness is a result of a convolution of the geometrical and inherent detector unsharpness function, divided by the magnification factor of the object onto the detector plane. Different approximations of this convolution result in ASTM E 1000 and ISO 17636-2 in different optimum values for the magnification factor for a given focal spot size of a X—ray tube and the basic spatial resolution of the detector. The higher contrast sensitivity, an advantage of digital radiography, compared to film radiography is furthermore improved when using higher X-ray voltages as used with film and smaller focal spots of the X-ray tubes. This allows a higher distance between object and detector resulting in reduced object scatter in the image. The interactions between all these parameters will be discussed and simple rules for practitioners will be derived in this contribution. T2 - 12th ECNDT 2018 CY - Gothenburg, Sweden DA - 11.06.2018 KW - Digital Radiology KW - Image unsharpness KW - Optimum magnification PY - 2018 AN - OPUS4-47351 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - DIN EN 12681:2017 für die radiographhische Gußteilprüfung mit Film oder digitalen Detektoren N2 - Vorstellung der Konzepte and Anwendungsbereiche der neuen Norm DIN EN 12681 in 2 Teilen: Film und digitale Prüfung T2 - Röntgentechnologietage 2018 CY - Stockelsdorf bei Lübeck, Germany DA - 20.02.2018 KW - Gussteilprüfung KW - DIN EN 12681:2017 KW - Filmbasierend KW - Digitale Röntgendetektoren PY - 2018 AN - OPUS4-47352 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - DIN EN ISO 17636:2013 für die radiographische Schweißnahtprüfung mit Film oder digitalen Detektoren N2 - Die aktuelle Normentwicklung für radiographische Schweißnahtprüfung wird diskutiert und die Konsequenzen für die praktische Anwendung anhand von Beispielen erläutert. T2 - Röntgentechnologietage 2018 CY - Stockelsdorf bei Lübeck, Germany DA - 20.02.2018 KW - Digitale Radiographie KW - Schweißnahtprüfung KW - DIN EN ISO 17636 PY - 2018 AN - OPUS4-47353 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Aktuelle Normungsaktivitäten in der industriellen Durchstrahlungsprüfung N2 - Neue Normen bei DIN, CEN ISO ASTM und IIW für die industrielle Durchstrahlungsprüfung mit Film und digitalen Detektoren. Stand der Technik und neue Entwicklungen T2 - Radiographie-Forum von Baker Hughes CY - Ahrensburg, Germany DA - 20.06.2018 KW - Wall thickness measurement KW - Aktuelle Normentwicklung KW - Schweißnahtprüfung KW - Digital radiography KW - Computed radiography (CR) KW - Digital Detector Array (DDA) KW - Tangential radiography KW - Image evaluation PY - 2018 AN - OPUS4-47354 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zscherpel, Uwe A1 - Ewert, Uwe T1 - Annual Report of Sub-Commission V-A "Radiography-based weld inspection" N2 - A Summary pf the activities of the IIW sub-commission V-A in 2018 for radiographic weld inspection. T2 - Annual Assembly of IIW CY - Bali, Indonesia DA - 15.07.2018 KW - Radiograpgy KW - Weld Inspection KW - International Institute of Welding PY - 2018 AN - OPUS4-47355 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zscherpel, Uwe A1 - Stegemann, Robert T1 - Update on Revision of ISO 24497 - NDT - MMM - Technique N2 - Presentation of the final compromise reached in 2018 for revision of ISO 24497, final draft for voting at ISO can be prepared now. T2 - IIW Annual Assembly 2018 CY - Bali, Indonesia DA - 15.07.2018 KW - NDT - Metal Magnetic Memory KW - Revision of ISO 24497 KW - New ISO draft PY - 2018 AN - OPUS4-47356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe T1 - Foreword N2 - The subject of this Special Issue is the fracture mechanics-based determination of the fatigue strength of weldments. Except for one, all papers were written in closer or wider relation to a methodology developed within the framework of the German Project cluster IBESS. Some of them provide background or supplementary information needed in that context but which is also relevant in a wider frame of research activities. The acronym IBESS stands for the topic of this Special Issue (in German: „Integrale Methode zu Bruchmechanischen Ermittlung der Schwingfestigkeit von Schweißverbindungen). Eight partners were involved. The cluster was cooperatively founded by the German Research Foundation (Deutsche Forschungsgemeinschaft) and by the German AiF Network (Arbeitsgemeinschaft industrieller Forschungsvereinigungen) for industrial research. KW - Fracture mechanics PY - 2018 DO - https://doi.org/10.1016/j.engfracmech.2018.05.046 SN - 0013-7944 VL - 198 IS - SI SP - 1 EP - 1 PB - Elsevier Ltd. AN - OPUS4-48696 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ramirez Caro, Alejandra A1 - Pauli, Jutta A1 - Mota, Berta A1 - Crasselt, Claudia A1 - Artemeva, Elena A1 - Schmidt, Wolfram A1 - Resch-Genger, Ute T1 - A Spectroscopic Study of the Superplasticizer Effect on Early Cement Hydration N2 - Organic/inorganic mixtures were prepared from ordinary Portland cement (OPC), water (w/c 0.22), a fluorescent dye in aqueous solution (stable at alkaline pH; BAM-I), and two different comb shape polycarboxylates (PCEs), i.e., high charge (PCE-HC) and low charge (PCE-LC), respectively. Rheological and calorimetric measurements were performed prior to optical studies in order to select PCE concentrations. Absorption and fluorescence spectroscopy of the system OPC + BAM-I (CBAM-I) revealed maxima of dye BAM-I located at 645 nm and 663 nm, respectively. In presence of PCE-HC and PCE-LC, these mixtures displayed a small red shift in reflectance and a faster decrease in intensity compared to studies with CBAM-I; however, only slight differences were observed between the different PCEs. With time, all systems exhibited a decrease in intensity of BAM-I in absorption/reflectance and emission. This could be caused by dye adsorption and possibly decomposition when in contact with cement particles or hydration products. T2 - The Sixth International Symposium on Nanotechnology in Construction (NICOM6) CY - Hong Kong, China DA - 02.12.2018 KW - Cement KW - Optical Spectroscopy KW - Dye KW - Hydration PY - 2018 SP - 1 EP - 9 AN - OPUS4-49378 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kindrachuk, Vitaliy A1 - Unger, Jörg F. T1 - A novel computational method for efficient evaluation of structural fatigue N2 - The methods of computational damage mechanics are well-established for the description of degradation of materials under monotone loading. An extension to structural damage induced by cyclic loading is however significantly limited. This is due to enormous computational costs required to resolve each load cycle by conventional temporal incremental integration schemes while a typical fatigue loading history comprises between thousands and millions of cycles. Despite the permanent increase of computational resources and algorithmic performance, a successful approach is rather based on the development of novel multiscale in time integration schemes. A Fourier transformation-based temporal integration (FTTI) is represented, which takes advantage of temporal scale separation incorporated into the cycle jump method. The response fields are approximated by a Fourier series whose coefficients undergo the evolution on a long-time scale. This is correlated with the evolution of the history variables, including damage, by means of the adaptive cycle jump method of various orders. The necessary extrapolation rates are obtained from the underlying solution of a short-time scale problem, which results from the oscillatory boundary condition and fulfills the global equilibrium of the Fourier coefficients. In this way, a remarkable speedup is achieved because the number of cycles to be fully integrated dramatically decreases. The key idea behind the FTTI method is that the global in space equilibrium problem is linear since it is decoupled from the evolution equations. The latter are solved in the quadrature points under response fields prescribed throughout the whole load cycle. Consequently, integration of a single load cycle is much more efficient than the conventional single scale integration where the global equilibrium iteration and the local iteration of the evolution equations are coupled. This results in an additional speedup of the FTTI method. The performance of the FTTI technique is demonstrated for two different constitutive behaviors: a viscoplastic model with a damage variable governed by the local equivalent viscoplastic strain; a quasi-brittle response where the damage variable is driven by a non-local equivalent strain. The latter is implicitly introduced as proposed by Peerlings. Both, the explicit and implicit extrapolation schemes are validated. The FTTI solutions agree very well with the reference cycle-by -cycle solutions, while significantly reducing the computational costs. The adaptive determination of the jump length can properly recognize the particular responses throughout the fatigue loading history (stationary fatigue, acceleration of fatigue damage when approaching failure) as well as stress redistribution phenomena. T2 - International Fatigue International Fatigue International Fatigue International Fatigue International Fatigue International Fatigue Congress Congress Congress 2018 CY - Poitiers, France DA - 27.05.2018 KW - Fatigue KW - Accelerated integration scheme PY - 2018 AN - OPUS4-46975 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nietzold, Carolin A1 - Dietrich, Paul A1 - Holzweber, M. A1 - Lippitz, Andreas A1 - Kamalakumar, A. A1 - Blanchard, V. A1 - Ivanov-Pankov, S. A1 - Weigel, W. A1 - Panne, Ulrich A1 - Unger, Wolfgang T1 - Surface chemical characterization of model glycan surfaces and shelf life studies of glycan microarrays using XPS, NEXAFS spectroscopy, ToF-SIMS and fluorescence scanning N2 - Biomedical applications, including functional biomaterials, carbohydrate-arrays, and glycan-based biosensors. The chemistry of glycan immobilization plays an essential role in the bioavailability and function of surface bound carbohydrate moieties. For biomedical applications the stability over time (shelf life) of glycan arrays is a crucial factor. Herein we report on approaches for surface and interface characterization relevant to the needs of production of glycan microarrays which were tested using model carbohydrate surfaces. For detailed characterization of glycan model surfaces we used a combination of X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption fine structure spectroscopy (NEXAFS) and ToF SIMS which are complementary techniques of surface chemical analysis. Links to fluorescence spectroscopy often used for characterization in the microarray community were established as well. In detail, amine-reactive silicon oxide and glass surfaces were used for anchoring oligosaccharides with an amino linker. The amount of surface bound carbohydrates was estimated by X-ray photoelectron spectroscopy (XPS). Glycan immobilization was investigated using lectins, which are glycan-binding molecules. A shelf life study of model glycan microarrays on epoxy-coated glass surfaces was done over a period of 160 days under different storage conditions utilizing fluorescence, ToF-SIMS and XPS analysis. It was shown that glycan activity of the models used can be maintained at least for half a year of storage at 4 °C. KW - Glycan microarray KW - XPS KW - NEXAFS KW - ToF-SIMS KW - Fluorescence PY - 2018 UR - https://www.sciencedirect.com/science/article/pii/S0169433218320300?via%3Dihub DO - https://doi.org/10.1016/j.apsusc.2018.07.133 SN - 0169-4332 SN - 1873-5584 VL - 459 SP - 860 EP - 873 PB - Elsevier B.V. AN - OPUS4-46212 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Keller, Christian A1 - Herbrich, Uwe T1 - Plastic Instability of Rate-Dependent Materials - Consideration of Isothermal and Adiabatic Conditions in Dynamic Tensile Tests - N2 - During dynamic processes, a certain range of strain rates is often observed along loaded structures and components. For precise numerical simulations, it is necessary to determine rate-dependent properties in dynamic tests and to describe the material behavior correctly within an appropriate domain of strain rates including adiabatic heating effects at higher strain rates, typically higher than 10 1/s. In principle, numerical simulations are compared to experimental results to verify the applied material models. For dynamic tensile tests considering ductile materials and large plastic deformation beyond uniform elongation, it is challenging to obtain comparable results due to plastic instability and necking of the specimen, e.g.. Based on the strain gradient in a general tensile specimen, a theoretical criterion was derived describing the plastic instability in rate-dependent materials under isothermal conditions in. It was applied to different multiplicative and additive constitutive relations and the analytical onset of necking was compared to results from numerical calculations of quasi-static and dynamic tensile tests. The simulations of a sheet-metal specimen with rectangular cross-section were carried out using the Finite Element Method and it was found that the numerical calculated and the theoretical predicted onset of plastic instability agree very good. The analytical criterion for instability holds even for specimens without geometrical or material imperfections and confirms that the onset of plastic instability must be considered a material characteristic. However, real dynamic problems with higher strain rates are not isothermal, the heat generated by plastic work is not dissipated to the surrounding and the temperature of the material increases significantly. Adiabatic heating and thermal softening must be considered within the constitutive relations of rate-dependent materials and the discussion of plastic instability. In this paper, an enhanced and more generalized approach for the description of the condition for stability is discussed and applied to phenomenological as well as more physical constitutive relations from the literature. This allows an individual assessment of the accuracy and verification of rate-dependent material models with respect to plastic instability. T2 - 13th World Congress on Computational Mechanics CY - New York, USA DA - 22.07.2018 KW - Plastic Instability KW - FEM KW - Rate-dependent Materials KW - Dynamic Tensile Test PY - 2018 AN - OPUS4-48923 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Widjaja, Martinus Putra A1 - Joannes, S. A1 - Bunsell, A. A1 - Mair, Georg A1 - Thionnet, A. T1 - The Application of a Reduced Volume Method for the Simulation of the Characterisation of a Carbon Fibre Pressure Vessel N2 - The developed model has certain limitations of the element size to be used in the simulation to characterise the strength of composite materials. A reduced volume method is proposed in order to reduce the number of degree of freedom of the finite element simulation.This study has revealed certain configuration to be followed to speed up the computation time. T2 - The 18th European Conference on Composite Materials CY - Athens, Greece DA - 24.06.2018 KW - Composite pressure vessel KW - Fibre break KW - Integral range KW - Representative volume element PY - 2018 SP - 1193-892 AN - OPUS4-48927 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Burgholzer, P. A1 - Berer, T. A1 - Ziegler, Mathias A1 - Thiel, Erik A1 - Ahmadi, Samim A1 - Gruber, J. A1 - Mayr, G. A1 - Hendorfer, G. T1 - Blind structured illumination as excitation for super-resolution photothermal radiometry N2 - The main drawback in radiometric imaging is the degradation of the spatial resolution with increasing depth, which results in blurred images for deeper lying structures. We circumvent this degradation with blind structured illumination, combined with a non-linear joint sparsity reconstruction algorithm. We demonstrate this by imaging a line pattern and a star-shaped structure through a metal sheet with a resolution four times better than the width of the thermal point-spread-function. The ground-breaking concept of super-resolution can be transferred from optics to diffusive imaging by defining a thermal point-spread-function similar to the Abbe limit for a certain optical wavelength. T2 - 14th Quantitative InfraRed Thermography Conference, QIRT 2018 CY - Berlin, Germany DA - 25.06.2018 KW - Thermography KW - Laser Thermography KW - Compressed Sensing KW - Super Resolution PY - 2018 AN - OPUS4-49940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Metz, Christian A1 - Franz, Philipp A1 - Fischer, C. A1 - Wachtendorf, Volker A1 - Maierhofer, Christiane T1 - Active thermography for quality assurance of 3D-printed polymer structures N2 - Additively manufactured test specimens made of polyamide 12 (PA 12) by Laser Sintering (LS) as well as of acrylnitril-butadien-styrol (ABS) by Fused Layer Modeling (FLM), were tested with active thermography. For this, two different excitation methods (flash and impulse excitation) were used and compared, regarding the suitability for the detection of constructed and imprinted defects. To increase the quality of the thermograms, data processing methods like thermal signal reconstruction (TSR) and Fourier-Transformation were applied. Furthermore, the long-term stability of the probes towards environmental stress, like UV-radiation, heat, water contact and frost is being investigated in the presented project with artificial weathering tests. T2 - 14th Quantitative InfraRed Thermography Conference CY - Berlin, Germany DA - 25.06.2018 KW - Additive manufacturing KW - Active thermography KW - Artificial weathering PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-453919 SP - Tu.3.A.2, 1 EP - 9 AN - OPUS4-45391 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heckel, Thomas A1 - Maierhofer, Christiane A1 - Gaal, Mate A1 - Schadow, Florian A1 - Brackrock, Daniel A1 - Blankschän, Michel A1 - Hosseini, Seyed A1 - Lodeiro, M. A1 - Segur, D. T1 - Comparison of the performance of ultrasonic non-destructive testing methods on inspection of fibre reinforced plastics N2 - In the last twenty years, components made of fibre-reinforced plastic became a prominently used material in safety-relevant structures. Periodic in-service inspection of these structures using reliable non-destructive testing methods became a relevant issue in the field. The goal of the EMRP-funded project VITCEA (Validated Inspection Techniques for Composites in Energy Applications) aims on the evaluation of the performance of various non-destructive testing methods on the inspection of fibre-reinforced plastics. In this talk the results of the comparison of different ultrasonic testing methods will be discussed. There are two challenges for the ultrasonic inspection of fibre-reinforced plastics. Firstly, different material properties of the fibre and the resin cause anisotropic acoustical behaviour of the material. Secondly, the physical layout of fibre layers leads to complex structures of fibre-reinforced plastic parts, and thus to a complex acoustical response. Both result in a reduction of the signal to noise ratio and make interpretation of measurement results rather extensive. During the VITCEA project, the acoustical behaviour of fibre-reinforced plate materials has been simulated. Specimens with artificial flaws for the evaluation of the detection thresholds have been designed and manufactured. Various mechanized ultrasonic testing methods including phased-array sensors, air-coupled transducers, immersion tank testing and contact technique have been evaluated on the specially designed specimen. Laboratory scale tests and a round robin test have been carried out. The probability of detection and the detection thresholds for each method have been estimated. T2 - ECNDT - European Conference on Non-Destructive Testing 2018 CY - Gothenburg, Sweden DA - 11.06.2018 KW - Comparison ndt methods FRP fibre reinforced plastics ultrasound PY - 2018 AN - OPUS4-47213 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maierhofer, Christiane A1 - Thiel, Erik A1 - Altenburg, Simon A1 - Mohr, Gunther A1 - Thiede, Tobias A1 - Mishurova, Tatiana A1 - Paul, Andrea A1 - Kranzmann, Axel A1 - Hilgenberg, Kai A1 - Pittner, Andreas A1 - Bruno, Giovanni A1 - Sommer, Konstantin A1 - Gumenyuk, Andrey T1 - Quality control in additive manufacturing via in-situ monitoring and non-destructive testing N2 - More than 80 representatives of SMEs, industrial companies and research institutes met on September 12 at the workshop "Challenges in Additive Manufacturing: Innovative Materials and Quality Control" at BAM in Adlershof to discuss the latest developments in materials and quality control in additive manufacturing. In special lectures, researchers, users and equipment manufacturers reported on the latest and future developments in additive manufacturing. Furthermore, funding opportunities for projects between SMEs and research institutions on a national and European level were presented. T2 - Challenges in Additive Manufacturing: Innovative Materials and Quality Control CY - Berlin, Germany DA - 12.09.2018 KW - Additive manufacturing KW - Quality control KW - Non-destructive testing KW - In-situ monitoring PY - 2018 AN - OPUS4-46072 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 UR - https://nbn-resolving.org/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 -