TY - CONF A1 - Abraham, O. A1 - Niederleithinger, Ernst A1 - Schmidt, F. A1 - Dalsgaard-Soerensen, J. A1 - Thoens, S. A1 - Chapeleau, X. A1 - Ferria, H. T1 - Infrastar Training School on Fatigue and Reliability Analysis of Structures - Training for Assessment of Risk N2 - The Infrastar training school provides lectures and hands-on training to Master and PhD students, early-stage researchers and (young) professionals on all aspects of asset management of civil infrastructures with respect to fatigue of materials. It is organized yearly since 2019 and up to 20 profiles are selected to attend the 3.5-day training. A team of 7 teachers provides insight in multi-disciplinary and intersectoral basic concepts in three core fields, ranging from the design to the dismantling of the structures (bridges and wind turbines): 1. Monitoring and auscultation, 2. Structural and action models, 3. Reliability, risk and decision analyses. Each year, a recognized expert is invited to deliver a keynote lecture to raise interest in a specific aspect of one of the fields covered. The presentation is recorded and published on the training school website. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Doctoral School KW - Fatigue KW - Reliability KW - Concrete PY - 2022 AN - OPUS4-56349 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abraham, O. A1 - Niederleithinger, Ernst A1 - Chapeleau, B. A1 - Klikowicz, P. A1 - Brühwiler, E. A1 - Bassil, A. A1 - Wang, Xin A1 - Chakraborty, J. A1 - Bayane, I. A1 - Leduc, D. A1 - Salamak, M. A1 - Katunin, A. A1 - Sörensen, J. D. T1 - Addressing the need to monitor concrete fatigue with non destructive testing: preliminary results of infrastar European project N2 - Fatigue is one of the most prevalent issues, which directly influences the service life expectancy of concrete structures. Fatigue has been investigated for years for steel structures. However, recent findings suggest that concrete structures may also be significantly subjected to the fatigue phenomena that could lead to premature failure of certainfatigue prone structural elements. To date, fatigue of reinforced concrete has been given little focus. and Kknowledge on the influence factors and durability/capacity effects on this material should be improved. Current technological means to measure fatigue in civil structures like bridges and wind turbines (both onshore and offshore) are outdated, imprecise and inappropriate. Meanwhile, this topic has got much more attention as dynamic loading on concrete structures plays an increasing role, e.g. in bridges with increasing traffic and heavier trucks, in wind energy production due to inherent vibrations e.g. in offshore wind turbine support structures affected by wind and waves. The European Innovative Training Networks (ITN) Marie Skłodowska-Curie Actions project INFRASTAR (Innovation and Networking for Fatigue and Reliability Analysis of Structures - Training for Assessment of Risk) provides research training for 12 PhD students. The project aims to improve knowledge for optimizing the design of new structures as well as for more realistic verification of structural safety and more accurate prediction of the remaining fatigue lifetime of existing structures. First, the INFRASTAR research framework is detailed. Then it will be exemplified through the presentation of the major results of the four PhD students involved in the work package dealing with auscultation and monitoring. This includes the development and improvement of Fiber Optics (FO) and Coda Wave Interferometry (CWI) for crack sizing and imagery, new sensor technologies and integration, information management, monitoring strategy for fatigue damage investigation and lifetime prediction. T2 - ASNT SMT/NDT-CE 2018 CY - New Brunswick, NJ, USA DA - 27.8.2018 KW - Concrete KW - Fatigue KW - Non-destructive testing KW - Reliabiilty PY - 2018 AN - OPUS4-45862 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit A1 - Costard, René A1 - Rosenbusch, Sjard Mathis A1 - Kadoke, Daniel A1 - Kind, Thomas A1 - Hicke, Konstantin A1 - Hüsken, Götz T1 - Structural behavior and damage assessment of a reinforced concrete wall by various NDT methods and embedded sensors under blast-loading N2 - A safety or security related assessment of explosions, accidental and intentional scenarios alike, often necessitate performance of replication-tests. Such test results are necessary to clarify the causes within the scope of forensic investigations. To gain important insights into the behavior of structures and materials under such loading, field tests may also be performed in accordance with different test standards. To determine the resistance of building-structures after explosions, estimation of the residual load-bearing capacity in addition to the assessment of dynamic structural response and damage to the building components is important. In most cases an evaluation of structural integrity is based only on the visual damage, resulting in an overestimation of the residual capacity. The Bundesanstalt für Materialforschung und -prüfung (BAM) operates the Test site for Technical Safety (TTS) on an area measuring about 12 km2 in the Federal State of Brandenburg for execution of true-to-scale explosion tests. At the TTS, building component testing was performed to assess the suitability of different non-destructive testing methods to characterize the dynamic structural response and damage resulting from the detonation of high explosives. Different blast-loading scenarios were realized by varying the net explosive mass and the standoff distance with all scenarios representing a near-field detonation. The test object was a reinforced concrete wall 2 m high, 2.5 m wide and 20 cm thick, fixed at both vertical edges. The dynamic loading of the wall was characterized with 8 piezoelectric pressure sensors flush-mounted on the front surface, thus measuring the reflected pressures from the shock wave. The tests were conducted with the aim of characterizing the global behavior of the wall under dynamic shock loading and the resulting local damage pattern, respectively. High speed digital image correlation was implemented in combination with multiple acceleration sensors to observe the rear surface of the wall to chart the dynamic deflection during the loading and to determine the residual deformation after the loading had ceased. In addition, one test specimen was instrumented with fiber optic sensor cables, both fixed to the rebars and embedded in the concrete-matrix, respectively. Firstly, these sensors were interrogated during the blast test by a distributed acoustic sensing (DAS) device using a particularly high sampling rate to measure the shock-induced vibrations in the structure with high temporal resolution. This delivers information on dynamics of compression and tension cycles from within the structure. Secondly, the local damage-pattern emerging during the series of blasts was determined via distributed fiber optic strain sensing (DSS) by interrogating the embedded fiber optic sensors with a high spatial resolution DSS device after each blast. This enabled the characterization of non-visual damage to the structure, in particular with regard to the formation of localized cracks in the concrete matrix. The DSS was further complimented by a structure-scanner based on ultrasonic measurements. Our contribution describes this new test approach in detail. Results of the three datasets, namely dynamic shock loading, global behavior of the test object and the local damage pattern will be presented. The suitability of the implemented measurement methods will be discussed in combination with the challenges in their application for technical safety evaluation of building components under explosive loading. T2 - 26th International Symposium on Military Aspects of Blast and Shock (MABS26) CY - Wollongong, Australia DA - 03.12.2023 KW - Blast tests KW - Reflected pressure KW - Embedded sensors KW - Distributed fiber optic sensors KW - Acceleration sensors KW - Digital image correlation KW - Ultrasonic structure-scanner PY - 2023 AN - OPUS4-58927 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ahmadi, Samim A1 - Thiel, Erik A1 - Ziegler, Mathias T1 - Thermal wave field engineering using structured 1D laser illumination N2 - Thermal waves are solutions of the heat diffusion equation for periodic boundary conditions and can be seen analogously to strongly damped waves. Although the underlying differential equation differs from the wave equation, the essential property for analogy between both equations is linearity such that superposition applies. This linearity is maintained even after a linear transformation, such as the Fourier transform from time to frequency domain. It follows that the temporal superposition principle is already used in active thermography, e.g. in pulsed thermography, as a superposition of many individual frequencies. However, the systematic spatial superposition has not yet been fully exploited, mainly due to a lack of suitable energy sources. As a first step, we are investigating how thermal wave fields of arbitrary space-time structures can be engineered using structured laser illumination. The proof of principle was shown using a laser coupled projector. Unfortunately, the available optical output power was limited due to the thermal stress limit of the device. That is why we are working towards a more sophisticated moving 1D array of high-power diode lasers. We characterized the novel light source and believe that apart from the benefit of spatial and temporal illumination it can combine the temporal regimes of impulse and lock-in thermography. In a second step, we investigate moving and oscillating line sources with different line shapes. We use a Green’s Function ansatz to analytically model the thermal wave propagation of structured 1D laser illumination in isotropic materials. Furthermore, we show some methods how they can be implemented. With this technique, we were able to accelerate our detection method firstly presented in for vertical narrow defects by factor three. Generally, we believe that this technique opens up similar opportunities than in other NDE methods. High-resolution ultrasound, for example, is also based on the superposition of single emitters and a recent concept suggests an option to deal with the diffusion wave character of the thermal waves. T2 - 62. International School of Quantum Electronics die Tagung “Progress in Photoacoustic & Photothermal Phenomena” CY - Erice, Italy DA - 06.09.2018 KW - Thermal wave KW - Thermal wave field KW - Thermal engineering KW - Structured laser illumination KW - 1d laser KW - Laser array KW - Laser thermography PY - 2018 AN - OPUS4-46193 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ahmadi, Samim A1 - Ziegler, Mathias A1 - Thiel, Erik A1 - Hirsch, Philipp Daniel A1 - Karagianni, Christina A1 - Burgholzer, P. A1 - Mayr, G. A1 - Jung, P. A1 - Caire, G. T1 - Photothermal super resolution image reconstruction using structured 1d laser illumination N2 - The separation of two closely spaced defects in fields of Thermographic NDE is very challenging. The diffusive nature of thermal waves leads to a fundamental limitation in spatial resolution. Therefore, super resolution image reconstruction can be used. A new concerted ansatz based on spatially structured heating and joint sparsity of the signal ensemble allows for an improved reconstruction of closely spaced defects. This new technique has been studied using a 1D laser array with randomly chosen illumination pattern. This paper presents the results after applying super resolution algorithms, such as the iterative joint sparsity (IJOSP) algorithm, to our processed measurement data. Different data processing techniques before applying the IJOSP algorithm as well as the influence of regularization parameters in the data processing techniques are discussed. Moreover, the degradation of super resolution reconstruction goodness by the choice of experimental parameters such as laser line width or number of measurements is shown. The application of the super resolution results in a spatial resolution enhancement of approximately a factor of four which leads to a better separation of two closely spaced defects. T2 - 46th Annual Review of Profress in Quantitative Nondestructive Evaluation CY - Portland, OR, USA DA - 14.07.2019 KW - Super resolution KW - Virtual wave KW - Laser thermography KW - 1d laser KW - Joint sparsity KW - Laser array KW - VCSEL array KW - High-power laser PY - 2019 AN - OPUS4-48591 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ahmadi, Samim A1 - Lecompagnon, Julien A1 - Hirsch, Philipp Daniel A1 - Burgholzer, Peter A1 - Jung, Peter A1 - Caire, Giuseppe A1 - Ziegler, Mathias T1 - Laser excited super resolution thermal imaging for nondestructive testing N2 - The work to be presented focuses on our most recent studies to laser excited super resolution (SR) thermography. The goal of nondestructive testing with SR is to facilitate the separation of closely spaced defects. Photothermal SR can be realized by performing structured illumination measurements in com-bination with the use of deconvolution algorithms in post-processing. We explain that stepwise as well as continuous scanning techniques are applicable to generate structured illumination measurements. Finally, we discuss the effect of experimental parameters and image processing techniques to find the optimal SR technique which leads to the highest reconstruction quality within laser thermography. T2 - Sensor and Measurement Science International Conference SMSI 2021 CY - Online meeting DA - 03.05.2021 KW - Super resolution KW - Laser thermography KW - Nondestructive testing KW - Laser scanning KW - Photothermal imaging PY - 2021 AN - OPUS4-52781 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ahmadi, Samim A1 - Ziegler, Mathias A1 - Thiel, Erik A1 - Hirsch, Philipp Daniel A1 - Karagianni, Christina A1 - Burgholzer, P. A1 - Mayr, G. A1 - Jung, P. A1 - Caire, G. T1 - Thermographic super resolution imaging using structured 1D laser illumination N2 - Thermographic nondestructive evaluation (NDE) is based on the interaction of thermal waves with inhomogeneities. These inhomogeneities are related to sample geometry or material composition. Although thermography is suitable for a wide range of inhomogeneities and materials, the fundamental limitation is the diffusive nature of thermal waves and the need to measure their effect radiometrically at the sample surface only. The propagation of the thermal waves from the heat source to the inhomogeneity and to the detection surface results in a degradation in the spatial resolution of the technique. A new concerted ansatz based on a spatially structured heating and a joint sparsity of the signal ensemble allows an improved reconstruction of inhomogeneities. As a first step to establish an improved thermographic NDE method, an experimental setup was built based on structured 1D illumination using a flash lamp behind a mechanical aperture. As a follow-up to this approach, we now use direct structured illumination using a 1D laser array. The individual emitter cells are driven by a pseudo-random binary pattern and are additionally shifted by fractions of the cell period. The repeated measurement of these different configurations enables to illuminate each spot of the sample surface in lateral direction. This allows for a reconstruction that makes use of joint sparsity. The measured data set is processed using super resolution image reconstruction algorithms such as the iterative joint sparsity (IJOSP) algorithm. Using this reconstruction technique and 150 different illumination patterns results in a spatial resolution enhancement of approximately a factor of four compared to the resolution of 5.9 mm for homogenously illuminated thermographic reconstruction. Further, new data processing techniques have been studied before applying the IJOSP algorithm that are more performant or less prone to errors regarding image reconstruction. The choice of regularization parameters in data processing as well as experimental parameters such as the illumination pattern as a variable heat flux density (i.e., the Neumann boundary condition for convolution with the constant Green's function) have a big influence on the reconstruction goodness. With analytical-numerical modelling and numerical FEM simulations, we studied the influence of the experimental parameters on the result of the non-linear IJOSP reconstruction. This has also been investigated experimentally e.g. using different laser line widths or more measurements per position. These studies are used to derive optimal conditions for a certain measurement image reconstruction technique. T2 - 20-th International Conference on Photoacoustic and Photothermal Phenomena CY - Moscow, Russia DA - 07.07.2019 KW - Super resolution KW - Virtual wave KW - Laser thermography KW - 1d laser KW - Joint sparsity KW - Laser array KW - VCSEL array KW - High-power laser PY - 2019 AN - OPUS4-48578 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ahmadi, Samim A1 - Lecompagnon, Julien A1 - Hirsch, Philipp Daniel A1 - Burgholzer, Peter A1 - Jung, Peter A1 - Caire, Giuseppe A1 - Ziegler, Mathias T1 - Neue Verfahren der thermografischen Super Resolution mit strukturierter 1D-Lasererwärmung N2 - Die thermografische ZfP basiert auf der Wechselwirkung von thermischen Wellen mit Inhomogenitäten. Die Ausbreitung von thermischen Wellen von der Wärmequelle zur Inhomogenität und zur Detektionsoberfläche entsprechend der thermischen Diffusionsgleichung führt dazu, dass zwei eng beieinander liegende Defekte fälschlicherweise als ein Defekt im gemessenen Thermogramm erkannt werden können. Um diese räumliche Auflösungsgrenze zu durchbrechen, also eine Super Resolution zu realisieren, kann die Kombination von räumlich strukturierter Erwärmung und numerischen Verfahren des Compressed Sensings verwendet werden. Für unsere Arbeiten benutzen wir Hochleistungs-Laser im Kilowatt-Bereich um die Probe entweder hochaufgelöst entlang einer Linie (1D) abzurastern oder strukturiert zu erwärmen. Die Verbesserung des räumlichen Auflösungsvermögens zur Defekterkennung hängt dann im klassischen Sinne direkt von der Anzahl der Messungen ab. Mithilfe des Compressed Sensings und Vorkenntnissen über das System ist es jedoch möglich die Anzahl der Messungen zu reduzieren und trotzdem Super Resolution zu erzielen. Wie viele Messungen notwendig sind und wie groß der Auflösungsgewinn gegenüber der konventionellen thermografischen Prüfung mit flächiger Erwärmung ist, hängt von einer Reihe von Messparametern, der Messstrategie, Probeneigenschaften und den verwendeten Rekonstruktionsalgorithmen ab. Unsere Studien befassen sich mit dem Einfluss der experimentellen Parameter, wie z.B. der Pulslänge der Laserbeleuchtung und der Größe des Laserspots. Weiterhin haben wir uns mit der Wahl der Parameter in der Rekonstruktion auseinandergesetzt, die einen Einfluss auf das im Compressed Sensing zugrundeliegende Minimierungsproblem haben. Für jeden getesteten Parametersatz wurde eine Rekonstruktionsqualität berechnet. Schließlich wurden die Defektrekonstruktionen basierend auf den Parameternsätzen verglichen, sodass eine Parameterwahl für hohe Rekonstruktionsqualitäten mit thermografischer Super Resolution empfohlen werden kann. T2 - DGZfP-Jahrestagung 2021 CY - Online meeting DA - 10.05.2021 KW - Super resolution KW - Laserthermografie KW - Strukturiertes Heizen KW - Photothermisch PY - 2021 AN - OPUS4-52783 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Scheuschner, Nils A1 - Gumenyuk, Andrey A1 - Straße, Anne A1 - Maierhofer, Christiane T1 - Towards the determination of real process temperatures in the LMD process my multispectral thermography N2 - Due to the rapid thermal cycles involved in additive manufacturing of metals, high internal stresses and peculiar microstructures occur, which influence the parts mechanical properties. To systematically examine their formation, in-process measurements of the temperature are needed. Since the part emissivity is strongly inhomogeneous and rapidly changing in the process, the applicability of thermography for the determination of thermodynamic temperatures is limited. Measuring the thermal radiation in different wavelengths simultaneously, temperature and emissivity can be separated. Here, we present results of a preliminary study using multispectral thermography to obtain real temperatures and emissivities in directed energy deposition (DED) processes. T2 - Thermosense: Thermal Infrared Applications XLIII CY - Online meeting DA - 12.04.2021 KW - Additive Manufacturing KW - Process monitoring KW - Multispectral thermography KW - Laser metal deposition KW - TES KW - LMD KW - Temperature emissivity separation PY - 2021 DO - https://doi.org/10.1117/12.2587881 AN - OPUS4-52515 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Scheuschner, Nils A1 - Pignatelli, Giuseppe A1 - Maierhofer, Christiane A1 - Straße, Anne A1 - Gornushkin, Igor B. A1 - Gumenyuk, Andrey T1 - Thermography and optical emission spectroscopy: Simultaneous temperature measurement during the LMD process N2 - For metal-based additive manufacturing, sensors and measuring systems for monitoring of the energy source, the build volume, the melt pool and the component geometry are already commercially available. Further methods of optics, spectroscopy and non-destructive testing are described in the literature as suitable for in-situ application, but there are only a few reports on practical implementations. Therefore, a new BAM project aims to develop process monitoring methods for the in-situ evaluation of the quality of additively manufactured metal components. In addition to passive and active thermography, this includes optical tomography, optical emission and absorption spectroscopy, eddy current testing, laminography, X-ray backscattering and photoacoustic methods. These methods are used in additive manufacturing systems for selective laser melting, laser metal deposition and wire arc additive manufacturing. To handle the sometimes huge amounts of data, algorithms for efficient preprocessing are developed and characteristics of the in-situ data are extracted and correlated to defects and inhomogeneities, which are determined using reference methods such as computer tomography and metallography. This process monitoring and fusion of data of different measurement techniques should result in a significant reduction of costly and time-consuming, destructive or non-destructive tests after the production of the component and at the same time reduce the production of scrap. Here, first results of simultaneous measurements of optical emission spectroscopy and thermography during the laser metal deposition process using 316L as building material are presented. Temperature values are extracted from spectroscopic data by fitting of blackbody emission spectra to the experimental data and compared with results from a thermographic camera. Measurements with and without powder flow reveal significant differences between welding at a pristine metal surface and previously melted positions on the build plate, illustrating the significant influence of the partial oxidation of the surface during the first welding process on subsequent welding. The measurement equipment can either be mounted stationary or following the laser path. While first results were obtained in the stationary mode, future applications for online monitoring of the build of whole parts in the mobile mode are planned. This research was funded by BAM within the focus area Material. T2 - 2nd international congress on welding, additive manufacturing and associated non-destructive testing CY - Metz, France DA - 05.06.2019 KW - Additive manufacturing KW - Laser metal deposition KW - Thermography KW - Optical emission spectroscopy KW - Process monitoring PY - 2019 AN - OPUS4-48228 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Maierhofer, Christiane A1 - Mohr, Gunther A1 - Hilgenberg, Kai A1 - Straße, Anne A1 - Gumenyuk, Andrey T1 - Verfahrensentwicklung für das Prozessmonitoring in der additiven Fertigung von Metallen - Thermografie N2 - Aktuell werden Prozessmonitoringsysteme in der additiven Fertigung (AM) zur Überwachung der Energiequelle, des Bauraums, des Schmelzbades und der Bauteilgeometrie zumindest im metallbasierten AM schon kommerziell angeboten. Weitere Verfahren aus den Bereichen der Optik, Spektroskopie und zerstörungsfreien Prüfung werden in der Literatur als geeignet für die in-situ Anwendung bezeichnet, es finden sich aber nur wenige Berichte über konkrete Umsetzungen in die Praxis. Die Bundesanstalt für Materialforschung und -prüfung hat ein neues Projekt gestartet, dessen Ziel die Entwicklung von Verfahren des Prozessmonitorings zur in-situ Bewertung der Qualität additiv gefertigter Bauteile in AM-Prozessen mit Laser- bzw. Lichtbogenquellen ist. Verschiedene Verfahren der zerstörungsfreien Prüfung, wie Thermografie, optische Tomografie, optische Emissionsspektroskopie, Wirbelstromprüfung und Laminografie werden in verschiedenen AM-Prozessen zum Einsatz gebracht und die Ergebnisse fusioniert. Die evaluierten Ergebnisse werden mit Referenzverfahren wie Computertomografie und Ultraschall-Tauchtechnik verglichen. Ziel ist eine deutliche Reduzierung aufwändiger und zeitintensiver, zerstörender oder zerstörungsfreier Prüfungen nach der Fertigung des Bauteiles und zugleich eine Verringerung von Ausschussproduktion. Hier wird das Projekt als Ganzes vorgestellt und der Fokus auf verschiedene Methoden der Temperaturmessung mit Hilfe der Thermografie gelegt. Anforderungen an die Messtechnik für verschiedene AM-Systeme werden diskutiert und erste experimentelle Ergebnisse werden präsentiert. T2 - 3. Tagung des DVM-Arbeitskreises Additiv gefertigte Bauteile und Strukturen CY - Berlin, Germany DA - 07.11.2018 KW - Additive Fertigung KW - Prozessmonitoring KW - ProMoAM KW - Thermografie PY - 2018 AN - OPUS4-46562 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Maierhofer, Christiane A1 - Mohr, Gunther A1 - Hilgenberg, Kai A1 - Straße, Anne A1 - Gumenyuk, Andrey T1 - Thermografische Prozessüberwachung bei der BAM – Additive Fertigung von Metallen N2 - Vorstellung des TF-Projektes ProMoAM und von Ergebnissen des in-situ Monitorings mit Thermografie T2 - Sitzung des VDI-GPL-FA 105.2 Additive Manufacturing-Metalle CY - Online meeting DA - 27.02.2019 KW - Additive manufacturing KW - In situ Monitoring KW - Thermograhy PY - 2019 AN - OPUS4-53534 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon T1 - Prozessüberwachung in der additiven Fertigung von Metallen an der BAM - Das Projekt ProMoAM N2 - Im Vortrag werden die verschiedenen Verfahren zum in-situ Monitoring und zur zerstörungsfreien Prüfung vorgestellt. T2 - 27. Sitzung des DGZfP Fachausschusses Materialcharakterisierung CY - Berlin, Germany DA - 14.11.2019 KW - Additive manufacturing KW - In situ Monitoring KW - Zerstörungsfreie Prüfung KW - Laserstrahlschmelzen im Pulverbett KW - Laserauftragschweißen PY - 2019 AN - OPUS4-53259 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Scheuschner, Nils A1 - Maierhofer, Christiane A1 - Mohr, Gunther A1 - Hilgenberg, Kai T1 - Thermography in laser powder bed fusion of metals: time over threshold as feasible feature in thermographic data N2 - Thermography is one on the most promising techniques for in-situ monitoring for metal additive manufacturing processes. The high process dynamics and the strong focus of the laser beam cause a very complex thermal history within the produced specimens, such as multiple heating cycles within single layer expositions. This complicates data interpretation, e.g., in terms of cooling rates. A quantity that is easily calculated is the time a specific area of the specimen is at a temperature above a chosen threshold value (TOT). Here, we discuss variations occurring in time-over-threshold-maps during manufacturing of a defect free cuboid specimen. T2 - 15th Quantitative InfraRed Thermography conference CY - Online meeting DA - 21.09.2020 KW - Additive Manufacturing KW - Process monitoring KW - Thermography KW - L-PBF KW - Time over threshold PY - 2020 AN - OPUS4-51630 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Breese, Philipp P. A1 - Oster, Simon A1 - Becker, Tina A1 - Scheuschner, Nils T1 - SAMMIE – Forschungssystem für die additive Fertigung von Metallen (PBF-LB/M) zur Entwicklung von In-situ-Überwachungs- und -prüfmethoden N2 - Die additive Fertigung von Metallen hat inzwischen einen Reifegrad erreicht, der einen Einsatz in vielen Industriezweigen ermöglicht oder in greifbare Nähe rückt. Die Vorteile liegen vor allem in der Möglichkeit der Fertigung komplexer Bauteile, die sich konventionell nicht oder nur sehr aufwändig produzieren lassen, sowie in der Fertigung von hochindividualisierten Bauteilen in kleinen Stückzahlen. Allerdings ist der additive Fertigungsprozess hoch komplex und fehleranfällig. Um eine insbesondere für sicherheitsrelevante Bauteile notwendige Qualitätskontrolle zu gewährleisten, ist aktuell aufwändige nachgelagerte ZfP der einzelnen Bauteile notwendig. Alternativen könnten die In-situ-Prozessüberwachung und -prüfung bieten, die aktuell aber noch keinen ausreichenden Entwicklungsstand erreicht haben. Industrielle Fertigungsanlagen bieten keine oder nur geringe Flexibilität und Zugänglichkeit, um umfangreiche Untersuchungen auf diesem Gebiet zu ermöglichen. Daher haben wir an der BAM ein System für den Prozess des selektiven Laserschmelzens (PBF-LB/M) entwickelt, genannt SAMMIE. Es bietet eine komplett offene Systemarchitektur mit voller Kontrolle über den Prozess und flexiblem Zugang zur Baukammer, z.B. optisch sowohl direkt als auch koaxial zum Fertigungslaser. In diesem Beitrag stellen wir das System vor und zeigen erste experimentelle Ergebnisse der In-situ-Überwachung und -prüfung: Thermografische Schmelzbadüberwachung, optische Tomografie und In-situ-Laserthermografie. SAMMIE ermöglicht uns grundlegende Untersuchungen, die helfen werden, die In-situ-Prozessüberwachung und -prüfung weiterzuentwickeln, neue Erkenntnisse über die additive Fertigung zu gewinnen und die Sicherheit und Zuverlässigkeit des Prozesses zu verbessern. T2 - DGZfP-Jahrestagung 2024 CY - Osnabrück, Germany DA - 06.05.2024 KW - PBF-LB/M KW - In situ monitoring KW - Anlage KW - Additive Fertigung KW - Prozessüberwachung KW - Additive Manufacturing PY - 2024 AN - OPUS4-60149 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon T1 - Introduction to ProMoAM N2 - A brief introduction to the project ProMoAM is given. T2 - 2nd Workshop on In-situ Monitoring and Microstructure Development in Additive Manufactured Alloys CY - Online meeting DA - 19.04.2021 KW - Additive Manufacturing KW - Process monitoring KW - ProMoAM PY - 2021 AN - OPUS4-52513 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Scheuschner, Nils A1 - Gumenyuk, Andrey A1 - Straße, Anne A1 - Maierhofer, Christiane T1 - Unraveling thermal radiation by multispectral thermography: Real temperatures in LMD N2 - Additive manufacturing of metals offers the opportunity to build parts with a high degree of complexity without additional costs, opening a new space for design optimization. However, the processes are highly complex and due to the rapid thermal cycles involved, high internal stresses and peculiar microstructures occur, which influence the parts mechanical properties. To systematically examine the formation of internal stresses and the microstructure, in-process spatially resolved measurements of the part temperature are needed. If the emissivity of the inspected part is known, its thermodynamic temperature can be reconstructed by a suited radiometric model. However, in additive manufacturing of metals, the emissivity of the part surface is strongly inhomogeneous and rapidly changing due to variations of, e.g., the degree of oxidation, the material state and temperature. Thus, here, the applicability of thermography in the determination of thermodynamic temperatures is limited. However, measuring the process thermal radiation at different wavelengths simultaneously enables one to separate temperature and emissivity spatially resolved to obtain further insight into the process. Here, we present results of an initial study using multispectral thermography to obtain real temperatures and emissivities in the powderfree LMD process. T2 - 2nd Workshop on In-situ Monitoring and Microstructure Development in Additive Manufactured Alloys CY - Online meeting DA - 19.04.2021 KW - Additive Manufacturing KW - Process monitoring KW - Multispectral thermography KW - Laser metal deposition KW - TES KW - LMD KW - Temperature emissivity separation PY - 2021 AN - OPUS4-52514 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon T1 - Prozessüberwachung in der additiven Fertigung von Metallen an der BAM: Das Projekt ProMoAM N2 - Vorstellung des TF-Projektes ProMoAM mit allen in-situ Verfahren und Referenzverfahren T2 - Sitzung des VDI AK Mess- und Automatisierungstechnik CY - Kassel, Germany DA - 03.03.2020 KW - Additive manufacturing KW - In situ monitoring KW - Zerstörungsfreie Prüfung PY - 2020 AN - OPUS4-53537 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Maierhofer, Christiane T1 - Improving additive manufacturing technologies by in-situ monitoring: Thermography N2 - Additive manufacturing of metals gains increasing relevance in the industrial field for part production. However, especially for safety relevant applications, a suitable quality assurance is needed. A time and cost efficient route to achieve this goal is in-situ monitoring of the build process. Here, the BAM project ProMoAM (Process monitoring in additive manufacturing) is briefly introduced and recent advances of BAM in the field of in-situ monitoring of the L-PBF and the LMD process using thermography are presented. T2 - Anwenderkonferenz Infratec GmbH CY - Online meeting DA - 04.11.2021 KW - Additive Manufacturing KW - Process monitoring KW - Thermography PY - 2021 AN - OPUS4-54026 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Krankenhagen, Rainer T1 - Continuous and Laplace transformable approximation for the temporal pulse shape of Xe-flash lamps for flash thermography N2 - In flash thermography, the temperature transient is strongly influenced by the temporal shape of the heating pulse for samples with high thermal diffusivity or very thin samples. Here, we present a closed phenomenological approximation of the temporal shape of pulses of Xe-flash lamps. It is a non-stitched solution, has a simple Laplace transform and is suitable for different lamps and energy settings. It is demonstrated that simulated temperature transients, based on this approximation, are well consistent with experimental data. T2 - 14th Quantitative InfraRed Thermography Conference CY - Berlin, Germany DA - 25.06.2018 KW - Finite pulse length KW - Flash thermography KW - Laplace transform KW - NDT KW - Pulse shape KW - Thickness determination PY - 2018 AN - OPUS4-45411 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Maierhofer, Christiane A1 - Pelkner, Matthias T1 - Process monitoring in metal AM @ BAM - The project ProMoAM N2 - Results of the project ProMoAM (Process monitoring in additive manufacturing) presented. Results from in-situ eddy current testing, optical emission spectroscopy, thermography, optical tomography as well as particle and gas emission spectroscopy are summarized and correlated to results from computed tomography for future in-situ defect detection. T2 - 3rd Meeting of WG6 (NDT in AM) of the EFNDT CY - Online meeting DA - 15.03.2022 KW - Additive Manufacturing KW - Process monitoring KW - ProMoAM PY - 2022 AN - OPUS4-54484 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Maierhofer, Christiane A1 - Mohr, Gunther A1 - Hilgenberg, Kai A1 - Straße, Anne A1 - Gumenyuk, Andrey T1 - Verfahrensentwicklung für die Prozessüberwachung in der additiven Fertigung - Thermografie N2 - Aktuell werden Prozessmonitoringsysteme in der additiven Fertigung (AM) zur Überwachung der Energiequelle, des Bauraums, des Schmelzbades und der Bauteilgeometrie zumindest im metallbasierten AM schon kommerziell angeboten. Weitere Verfahren aus den Bereichen der Optik, Spektroskopie und zerstörungsfreien Prüfung werden in der Literatur als geeignet für die in-situ Anwendung bezeichnet, es finden sich aber nur wenige Berichte über konkrete Umsetzungen in die Praxis. Die Bundesanstalt für Materialforschung und -prüfung hat ein neues Projekt gestartet, dessen Ziel die Entwicklung von Verfahren des Prozessmonitorings zur in-situ Bewertung der Qualität additiv gefertigter Bauteile in AM-Prozessen mit Laser- bzw. Lichtbogenquellen ist. Verschiedene Verfahren der zerstörungsfreien Prüfung, wie Thermografie, optische Tomografie, optische Emissionsspektroskopie, Wirbelstromprüfung und Laminografie werden in verschiedenen AM-Prozessen zum Einsatz gebracht und die Ergebnisse fusioniert. Die evaluierten Ergebnisse werden mit Referenzverfahren wie Computertomografie und Ultraschall-Tauchtechnik verglichen. Ziel ist eine deutliche Reduzierung aufwändiger und zeitintensiver, zerstörender oder zerstörungsfreier Prüfungen nach der Fertigung des Bauteiles und zugleich eine Verringerung von Ausschussproduktion. Hier wird das Projekt als Ganzes vorgestellt und der Fokus auf verschiedene Methoden der Temperaturmessung mit Hilfe der Thermografie gelegt. Anforderungen an die Messtechnik für verschiedene AM-Systeme werden diskutiert und erste experimentelle Ergebnisse werden präsentiert. T2 - Innotesting 2019 CY - Wildau, Germany DA - 21.02.2019 KW - Additive Fertigung KW - Thermografie KW - Prozessüberwachung PY - 2019 AN - OPUS4-47457 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Scheuschner, Nils A1 - Maierhofer, Christiane A1 - Ulbricht, Alexander A1 - Mohr, Gunther A1 - Heinrich, P. A1 - Baum, D. A1 - Hilgenberg, Kai T1 - In-situ Prozessüberwachung in der additiven Fertigung von Metallen mittels optischer Verfahren N2 - Einer der aussichtsreichsten Ansätze, die Qualität und Sicherheit der gefertigten Teile in der metallbasierten additiven Fertigung (AM) zu erhöhen und die Notwendigkeit aufwändiger und zeitintensiver, zerstörender oder zerstörungsfreier Prüfungen (ZfP) nach der Fertigung zu verringern, liegt in dem Einsatz von in-situ Prozessüberwachungstechniken. Bereits jetzt werden erste Messsysteme zur Kontrolle der Energiequelle, des Bauraums, des Schmelzbades und der Bauteilgeometrie kommerziell angeboten. Weitere ZfP Verfahren, wie z.B. die aktive und passive Thermografie, werden in der Literatur als geeignet für die in-situ Anwendung angesehen, allerdings gibt es noch wenig konkrete praktische Umsetzungen, da die Möglichkeiten und individuellen Grenzen dieser Methoden, angewendet auf AM, noch nicht ausreichend erforscht sind. Aus diesem Grund verfolgt die BAM mit dem Projekt „Process Monitoring of AM“ (ProMoAM) im Themenfeld Material das Ziel, Verfahren des Prozessmonitorings zur in-situ Bewertung der Qualität additiv gefertigter Metallbauteile weiterzuentwickeln. Im Beitrag wird zunächst das Projekt vorgestellt und anschließend der Fokus auf eine Messserie gelegt, in der Probekörper aus dem austenitischen Edelstahl 316L mit lokal variierenden Prozessparametern mittels selektiven Laserschmelzen (L-PBF) aufgebaut wurden. Der Bauprozess wurde hierbei durch das maschineneigene, koaxial arbeitende Photodiodensystem (Melt-Pool-Monitoring), einer Mittelwellen-Infrarotkamera und einer optischen Tomografiekamera im sichtbaren Wellenlängenbereich (Langzeitbelichtung für die Dauer eines Lagenaufbaus mit einer CMOS-Kamera mit hoher Ortsauflösung) simultan überwacht. Als Referenz für diese Methoden wurden die Probekörper mittels Computertomografie untersucht. Für die dabei anfallenden teils großen Datenmengen wurden Algorithmen für ein effizientes Preprocessing entwickelt. Es wurden Merkmale der Messdaten in Korrelation zu Fehlern und Inhomogenitäten extrahiert, welche für die einzelnen Methoden vergleichend vorgestellt und diskutiert werden. T2 - 5. Tagung des Arbeitskreises Additiv gefertigte Bauteile und Strukturen CY - Online meeting DA - 04.11.2020 KW - Additive Fertigung KW - Prozessüberwachung KW - Thermografie KW - Optische Tomografie KW - Computertomografie KW - L-PBF KW - AM KW - CT KW - In-situ PY - 2020 AN - OPUS4-51627 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Becker, Tina A1 - Breese, Philipp Peter A1 - Maierhofer, Christiane T1 - Towards hyperspectral in-situ temperature measurement in metal additive manufacturing N2 - The industrial use of additive manufacturing for the production of metallic parts with high geometrical complexity and lot sizes close to one is rapidly increasing as a result of mass individualisation and applied safety relevant constructions. However, due to the high complexity of the production process, it is not yet fully understood and controlled, especially for changing (lot size one) part geometries. Due to the thermal nature of the Laser-powder bed fusion (L-PBF) process – where parts are built up layer-wise by melting metal powder via laser - the properties of the produced part are strongly governed by its thermal history. Thus, a promising route for process monitoring is the use of thermography. However, the reconstruction of temperature information from thermographic data relies on the knowledge of the surface emissivity at each position on the part. Since the emissivity is strongly changing during the process due to phase changes, great temperature gradients, possible oxidation, and other potential influencing factors, the extraction of real temperature data from thermographic images is challenging. While the temperature development in and around the melt pool, where melting and solidification occur is most important for the development of the part properties. Also, the emissivity changes are most severe in this area, rendering the temperature deduction most challenging. A possible route to overcome the entanglement of temperature and emissivity in the thermal radiation is the use of hyperspectral imaging in combination with temperature emissivity separation (TES) algorithms. As a first step towards the combined temperature and emissivity determination in the L-PBF process, here, we use a hyperspectral line camera system operating in the short-wave infrared region (0.9 µm to 1.7 µm) to measure the spectral radiance emitted. In this setup, the melt pool of the L-PBF process migrates through the camera’s 1D field of view, so that the radiation intensities are recorded simultaneously for multiple different wavelength ranges in a spatially resolved manner. At sufficiently high acquisition frame rate, an effective melt pool image can be reconstructed. Using the grey body approximation (emissivity is independent of the wavelength), a first, simple TES is performed, and the resulting emissivity and temperature values are compared to literature values. Subsequent work will include reference measurements of the spectral emissivity in different states allowing its analytical parametrisation as well as the adaption and optimisation of the TES algorithms. An illustration of the proposed method is shown in Fig.1. The investigated method will allow to gain a deeper understanding of the L-PBF process, e.g., by quantitative validation of simulation results. Additionally, the results will provide a data basis for the development of less complex and cheaper sensor technologies for L-PBF in-process monitoring (or for related process), e.g., by using machine learning. T2 - 21st International Conference on Photoacoustic and Photothermal Phenomena CY - Bled, Slovenia DA - 19.06.2022 KW - Thermography KW - Additive manufacturing KW - L-PBF KW - Hyperspectral PY - 2022 AN - OPUS4-55152 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Mohr, Gunther A1 - Baesso, Ilaria A1 - Straße, Anne A1 - Pittner, Andreas A1 - Pignatelli, Giuseppe A1 - Seeger, Stefan A1 - Nazarzadehmoafi, Maryam A1 - Ehlers, Henrik A1 - Gohlke, Dirk A1 - Homann, Tobias A1 - Scheuschner, Nils A1 - Ulbricht, Alexander A1 - Heinrich, P. A1 - Maierhofer, Christiane T1 - Process monitoring of additive manufacturing of metals - an overview of the project ProMoAM N2 - The project ProMoAM is presented. The goal of the project is to evaluate which NDT techniques or combination of techniques is suited for in-situ quality assurance in additive manufacturing of metals. To this end, also 3d-data fusion and visualization techniques are applied. Additional ex-situ NDT-techniques are used as references for defect detection and quantification. Feasability studies for NDT-techniques that are presently not applicable for in-situ use are performed as well. The presentation gives a brief overview of the whole project and the different involved NDT-techniques. T2 - Workshop od Additive Manufacturing: Process, materials, simulation & implants CY - Berlin, Germany DA - 13.05.2019 KW - Additive manufacturing KW - Process monitoring KW - NDT PY - 2019 AN - OPUS4-48087 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Avila, Luis A1 - Rehmer, Birgit A1 - Skrotzki, Birgit A1 - Graf, B. A1 - Rethmeier, Michael A1 - Ulbricht, Alexander T1 - Ermüdungsverhalten und Versagensmechanismen von additiv mittels LPA hergestelltem TiAl6V4 N2 - Die Untersuchung und Charakterisierung der Entwicklung/Änderung der Mikrostruktur, der mechanischen Eigenschaften sowie der Lebensdauer additiv gefertigter metallischer Werkstoffe hat bisher, vor allem im Hinblick auf die komplexe Belastungsfälle bei sicherheitsrelevanten Anwendungen, mit der rasanten Entwicklung der Fertigungstechniken nicht Schritt gehalten. Im Rahmen dieser Arbeit wurde eine Charakterisierung des Ermüdungsverhaltens von additiv gefertigten TiAl6V4 im Low-Cycle-Fatigue Bereich (niederzyklische Ermüdung) nach Norm ISO 12206 mit Dehnungsamplituden von 0.3 bis zu 1.0 % und bei Raumtemperatur, 250°C und 400°C durchgeführt. Die TiAl6V4 Proben wurden aus zylindrischen Halbzeugen gefertigt, welche durch Laser-Pulver-Auftragsschweißen mit einer optimierten Aufbaustrategie hergestellt wurden. Die optimierte Aufbaustrategie beinhaltet variierende Spurüberlappungsgraden, die die Fertigung der dünnen zylindrischen Körper ohne weitere Ausgleichslagen ermöglicht. Das Werkstoffverhalten wird anhand von Wechselverformungskurven sowie einer Darstellung der Lebensdauer in einem Wöhler-Diagramm beschrieben. Ein Fitting der Lebensdauer-Daten erfolgt anhand der Manson-Coffin-Basquin Beziehung. Eine Eingangscharakterisierung der mikrostrukturellen Merkmale inklusive Bindefehler aus dem Herstellungsprozess wird durch Lichtmikroskopie und hochauflösende Computertomographie (CT) durchgeführt. Der Versagensmechanismus während der Belastung wird anhand von Zwischenuntersuchungen mit CT und einem unterbrochenen Versuch mit ausgewählten Versuchsparametern beschrieben. Nach dem Versagen wurden die Proben am REM, mit Lichtmikroskopie und mit CT fraktographisch in Längs- und Querrichtung untersucht. Die erfassten Lebensdauern sind ähnlich zu denen aus herkömmlichen Studien und liegen unter derjenigen von dem konventionell hergestellten (geschmiedeten) Werkstoff. In dieser Arbeit wurden für den untersuchten Werkstoff bei anwendungs- und sicherheitsrelevanten Belastungszuständen (hohe Temperaturen, zyklische Plastizität) neue experimentelle Daten und Kennwerte ermittelt und Verständnis über das mechanische Verhalten und die Entwicklung der Mikrostruktur aufgebaut. Darüber hinaus wurde Verständnis über die Rolle von Bindefehlern und anderen typisch für AM auftretenden Gefügemerkmalen auf das Versagensverhalten von DED-L TiAl6V4 gewonnen. T2 - DGM Fachausschuss Titan CY - Liebherr-Aerospace Lindenberg GmbH, Germany DA - 12.11.2019 KW - LCF KW - Titan KW - Ti-6Al-4V KW - Ti64 KW - TiAl5V4 KW - Additive Fertigung KW - CT KW - Mikrostruktur KW - Zugeigenschaften KW - Low Cycle Fatigue PY - 2019 AN - OPUS4-49758 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Avila, Luis A1 - Rehmer, Birgit A1 - Skrotzki, Birgit A1 - Graf, B. A1 - Rethmeier, Michael A1 - Ulbricht, Alexander T1 - Low cycle fatigue behavior and failure mechanisms of additively manufactured Ti-6Al-4V N2 - Despite of the significant advances in AM process optimization there is still a lack of experimental results and understanding regarding the mechanical behavior and microstructural evolution of AMparts, especially in loading conditions typical for safety-relevant applications e.g. in the aerospace or power engineering. Within the scope of the presented investigations, a characterization of the fatigue behavior of additively manufactured Ti-6Al-4V in the low cycle fatigue regime was carried out in the range of 0.3 to 1.0 % strain amplitude at room temperature, 250°C and 400°C. The Ti-6Al-4V specimens are machined out of lean cylindrical rods, which were fabricated using powder laser metal deposition (LMD) with an improved build-up strategy. The improved strategy incorporates variable track overlap ratios to achieve a constant growth in the shell and core area. The low-cycle-fatigue behavior is described based on cyclic deformation curves and strain-based fatigue life curves. The lifetimes are fitted based on the Manson-Coffin-Basquin relationship. A characterization of the microstructure and the Lack-of-Fusion (LoF)-defect-structure in the as-built state is performed using optical light microscopy and high-resolution computed tomography (CT) respectively. The failure mechanism under loading is described in terms of LoF-defects-evolution and crack growth mechanism based on an interrupted LCF test with selected test parameters. After failure, scanning electron microscopy, digital and optical light microscopy and CT are used to describe the failure mechanisms both in the longitudinal direction and in the cross section of the specimens. The fatigue lives obtained are comparable with results from previous related studies and are shorter than those of traditionally manufactured (wrought) Ti-6Al-4V. In this study new experimental data and understanding of the mechanical behavior under application-relevant loading conditions (high temperature, cyclic plasticity) is gained. Furthermore, a better understanding of the role of LoFdefects and AM-typical microstructural features on the failure mechanism of LMD Ti-6Al-4V is achieved. T2 - First European Conference on Structural Integrity of Additively Manufactured Materials (ESIAM19) CY - Trondheim, Norway DA - 09.09.2019 KW - High Temperature Testing KW - Titanium KW - Ti-6Al-4V KW - Additive Manufacturing KW - Computed Tomography KW - Microstructure KW - Tensile Properties KW - Low Cycle Fatigue PY - 2019 AN - OPUS4-49492 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Avila, Luis A1 - Rehmer, Birgit A1 - Skrotzki, Birgit A1 - Graf, B. A1 - Rethmeier, Michael A1 - Ulbricht, Alexander T1 - Ermüdungsverhalten und Versagensmechanismen von additiv mittels LPA hergestelltem TiAl6V4 N2 - Die Untersuchung und Charakterisierung der Entwicklung/Änderung der Mikrostruktur, der mechanischen Eigenschaften sowie der Lebensdauer additiv gefertigter metallischer Werkstoffe hat bisher, vor allem im Hinblick auf die komplexe Belastungsfälle bei sicherheitsrelevanten Anwendungen, mit der rasanten Entwicklung der Fertigungstechniken nicht Schritt gehalten. Im Rahmen dieser Arbeit wurde eine Charakterisierung des Ermüdungsverhaltens von additiv gefertigten TiAl6V4 im Low-Cycle-Fatigue Bereich (niederzyklische Ermüdung) nach Norm ISO 12206 mit Dehnungsamplituden von 0.3 bis zu 1.0 % und bei Raumtemperatur, 250°C und 400°C durchgeführt. Die TiAl6V4 Proben wurden aus zylindrischen Halbzeugen gefertigt, welche durch Laser-Pulver-Auftragsschweißen mit einer optimierten Aufbaustrategie hergestellt wurden. Die optimierte Aufbaustrategie beinhaltet variierende Spurüberlappungsgraden, die die Fertigung der dünnen zylindrischen Körper ohne weitere Ausgleichslagen ermöglicht. Das Werkstoffverhalten wird anhand von Wechselverformungskurven sowie einer Darstellung der Lebensdauer in einem Wöhler-Diagramm beschrieben. Ein Fitting der Lebensdauer-Daten erfolgt anhand der Manson-Coffin-Basquin Beziehung. Eine Eingangscharakterisierung der mikrostrukturellen Merkmale inklusive Bindefehler aus dem Herstellungsprozess wird durch Lichtmikroskopie und hochauflösende Computertomographie (CT) durchgeführt. Der Versagensmechanismus während der Belastung wird anhand von Zwischenuntersuchungen mit CT und einem unterbrochenen Versuch mit ausgewählten Versuchsparametern beschrieben. Nach dem Versagen wurden die Proben am REM, mit Lichtmikroskopie und mit CT fraktographisch in Längs- und Querrichtung untersucht. Die erfassten Lebensdauern sind ähnlich zu denen aus herkömmlichen Studien und liegen unter derjenigen von dem konventionell hergestellten (geschmiedeten) Werkstoff. In dieser Arbeit wurden für den untersuchten Werkstoff bei anwendungs- und sicherheitsrelevanten Belastungszuständen (hohe Temperaturen, zyklische Plastizität) neue experimentelle Daten und Kennwerte ermittelt und Verständnis über das mechanische Verhalten und die Entwicklung der Mikrostruktur aufgebaut. Darüber hinaus wurde Verständnis über die Rolle von Bindefehlern und anderen typisch für AM auftretenden Gefügemerkmalen auf das Versagensverhalten von DED-L TiAl6V4 gewonnen. T2 - Werkstoffwoche 2019 CY - Dresden, Germany DA - 18.09.2019 KW - Titan KW - TiAl5V4 KW - Ti-6Al-4V KW - Ti64 KW - Additive Fertigung KW - CT KW - Mikrostruktur KW - Zugeigenschaften KW - Low Cycle Fatigue KW - LCF PY - 2019 AN - OPUS4-49755 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska T1 - Charakterisierung von Salzbeton und alkali-aktivierten Material basierend auf der Schallemissionsanalyse N2 - Nach einer kurzen Einführung in die Schallemissionsprüfung und -Analyse wird ein Versuchsstand vorgestellt, der im Rahmen des Themenfeldprojektes Seal Waste Safe installiert wurde. Schwerpunkt des Vortrages sind die Schallemissionsmessungen an einem 150 l Demonstrator aus Salzbeton und einem weiteren aus alkali-aktiviertem Material. Neben der konventionellen Schallemissionsanaylse mit Aktivitäts- und Intensitätsparametern der Zeitsignale, werden auch frequenzbasierte Parameter zur Analyse andiskutiert. N2 - After a brief introduction to acoustic emission testing and analysis, an experimental test setup is presented, which was part of the Seal Waste Safe project (internal BAM project 2019-2022). Herein, the acoustic emission measurements of a 150 l demonstrator made of salt concrete and another one made of alkali-activated material are focused. In addition to the conventional acoustic emission analysis regarding the activity and intensity parameters of the detected time signals, also frequency-based parameters were discussed for analysis. T2 - Dauerhafte Verschlussbauwerke für Endlager CY - Online meeting DA - 14.2.2022 KW - Acoustic Emission KW - Schallemission KW - Salzbeton KW - Alkali aktiviertes Material KW - Geopolymer PY - 2022 AN - OPUS4-54937 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska T1 - Acoustic emission of fibre reinforced AlSi12CuMgNi alloy under compression N2 - Typically, the near-eutectic Al-Si alloys consist of highly interconnected three-dimensional network of the eutectic Silicon (Si) and intermetallics embedded into Aluminium (Al) matrix. For further improvement of the mechanical properties of such alloys, often, one single ceramic reinforcement phase, e.g. silicon carbide (SiC) or aluminium oxide (Al2O3) in the form of fibres or particles is added. However, hybrid reinforcements (fibres and particles) can further improve wear resistance and fracture toughness, and additionally, reduce anisotropy of the material. The engineering of metal matrix composites (MMC) for specific application requirements benefits from a comprehensive knowledge of the failure behaviour. Therefore, damage evolution under compression was investigated on: - pure near-eutectic AlSi12CuMgNi matrix alloy - type I: matrix reinforced with random-planar oriented Al2O3 short fibres (15 vol.%) - type II: matrix reinforced with random-planar oriented Al2O3 short fibres (7 vol.%) and additional SiC particles (15 vol.%) The analysis of damage mechanism was carried out in two rather independent but complementary studies. First, selected sister samples of every material were exposed to quasi-static compression (traverse control). The compression tests were interrupted at different strain levels. Miniature cylinders with a diameter of 1mm were extracted from the pre-strained samples and investigated by synchrotron computed tomography (SX-µCT) with a spatial resolution of about 0.7 µm. For the pure matrix alloy, microcracks are confined to the intermetallic particles and to the eutectic Si, hence no damage was observed in the Aluminium. The composite type II revealed a more effective strain accumulation (less damage) than type I at low plastic strain (up to 5 %), but a more catastrophic damage development due to cracking of the SiC clusters at higher strain levels. The second approach to study the damage initiation and accumulation in the materials subjected to compressive load was Acoustic Emission (AE) analysis. In this case the in-situ monitoring of the acoustic emission signal was performed during compression tests on specimens with dimension of several mm. For all three material types, AE activity set at 2% strain. Differences in AE behaviour of the three materials was proven based on AE hitrate, signal peak amplitudes as well as weighted peak frequencies (WPF). Future work focuses on combination of AE and SX-µCT aiming for more detailed knowledge on damage mechanism of metal matrix composites. T2 - Schall21 CY - Online meeting DA - 24.02.2021 KW - AlSi12CuMgNi KW - Al-Si alloys KW - Acoustic emission KW - Tension PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-534268 UR - https://www.dgzfp.de/seminar/schall21 AN - OPUS4-53426 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska A1 - Sanabria, S. T1 - Der Verformungswiderstand im Holz und die Rolle der Holzstrahlen N2 - Von den Zellulosefibrillen über die Zellwand und die Anordnung der Früh- und Spätholzzellen in einem Jahrring bis hin zum Balken von Natur aus ist Holz ein optimierter Hochleistungswerkstoff, der Handwerker, Architekten, Ingenieure und Wissenschaftler fasziniert und begeistert. Im digitalen Zeitalter werden neben Standard-Laborexperimenten zunehmend Modelle und Simulationen eingesetzt, um das Verhalten des Materials unter verschiedenen Belastungen besser zu verstehen und vorherzusagen. Dazu werden Zahlenwerte von Verformungen im subzellulären Maßstab benötigt, die nun in Experimenten an der TOMCAT-Beamline (TOmographic Microscopy and Coherent rAdiology ExperimenTs) der SLS (Swiss Light Source) gewonnen werden konnten: Holzproben aus Fichte ( Picea abies Karst.) mit einem Prüfquerschnitt von mindestens 1 mm² auf Zug oder Druck beansprucht. Die strukturellen Veränderungen auf Zellebene wurden mittels Computertomographie erfasst. Für die nachträgliche Analyse der 3D-Mikrostruktur von Holz wurde ein Ansatz entwickelt, der es ermöglicht, einzelne Zellen, die in mehreren Tomogrammen unterschiedlicher Belastungszustände erfasst wurden, zu verfolgen. Dabei wurden die Zellgeometrien und das subzelluläre Deformationsverhalten quantifiziert. Unter Zugbelastung beispielsweise verengt sich die Zellwanddicke um ca. 0,8%, das sind bei der gemessenen mittleren Zellwanddicke von 3,5 µm ca. 28 nm. Diese und andere Erkenntnisse liefern nun einen direkten numerischen Zusammenhang zwischen Verformungen der Holzmikrostruktur und dem daraus resultierenden makroskopischen Verhalten. T2 - 5. Holzanatomisches Kolloquium CY - Dresden, Germany DA - 09.09.2021 KW - Holz KW - Wood materials KW - Individual cell tracking KW - Mikro CT PY - 2021 AN - OPUS4-53403 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska A1 - Hüsken, Götz A1 - Pirskawetz, Stephan A1 - Gründer, Klaus-Peter A1 - Kadoke, Daniel A1 - Baer, Wolfram A1 - Wossidlo, Peter A1 - Homann, Tobias A1 - Prager, Jens A1 - Stajanca, Pavol A1 - Habib, Abdel Karim A1 - Zauner, Michaela A1 - Sause, Markus G. R. A1 - Vergeynst, Lidewei A1 - Brunner, Andreas J. A1 - Niemz, Peter T1 - Acoustic emission testing N2 - The phenomenon of acoustic emission (AE) and fundamentals of AE testing procedures are presented. AE based failure analysis of reinforced concrete beam under bending load, steel pipe segments under bending load and wood based materials under tension load are discussed. T2 - INFRASTAR, Training Week #03 at AAU CY - Aalborg, Denmark DA - 04.06.2018 KW - Acoustic emission PY - 2018 AN - OPUS4-45147 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska T1 - Wenn es im Holz knackt. Über die Herausforderung, kritische Versagensvorgänge in Holzstrukturen mittels Schallemissionsanalyse zu identifizieren N2 - Um die Versagensabläufe über die verschiedenen Skalen im Holzwerkstoff verfolgen zu können, werden Zugversuche an Lagenhölzern mittels Schallemissionsmessung überwacht. Synchron erfolgen In-situ-Messungen mit Digitaler Bildkorrelation bzw. Synchrotron-Mikro-Computertomographie. Die Kombination aller Ergebnisse wie auch die Anwendung der frequenzbasierten Mustererkennung und die Simulation ausgewählter Versuche zielen auf die Identifizierung zugrunde liegender Mechanismen hin. Abschließend werden Ansätze für ein Monitoring von Holzstrukturen diskutiert. T2 - 419. Sitzung AK Berlin der DGZFP CY - Online meeting DA - 15.09.2020 KW - Acoustic Emission (AE) KW - Holzwerkstoffe KW - Mustererkennung KW - Monitoring Konzept PY - 2020 AN - OPUS4-51361 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska A1 - Brunner, A. J. T1 - Towards predictor development for assessing structural integrity of components made from wood materials using Acoustic Emission monitoring and signal analysis N2 - Against the background of sustainable resource management and efficiency, wood-based materials are currently experiencing a revival and, among others, plywood, Laminated Veneer Lumber and glued laminated timber are becoming increasingly more important in the building sector. Even though these materials are so-called engineered products, the element wood is naturally grown with intrinsic variability in mechanical properties and requires professional handling on-site. Otherwise, load-bearing structures made of wood materials may entail certain risks. Critical situations can, in principle, be avoided by implementing a structural health monitoring system into components or structures made from wood material. The aim is to indicate accumulation of mechanical damage and to eliminate or at least significantly reduce the risk of unexpected failure. Toward this purpose, the failure behavior of several layered wood materials under quasi-static tension was investigated in laboratory-scale experiments by means of acoustic emission (AE) measurement. Based on spectral analysis and pattern recognition, two classes of AE signals are identified for each investigated lay-up that are characterized by either low or high frequency contents in the respective power spectra. AE activity and intensity of both signal classes are analyzed, striving for predictors appropriate for AE monitoring concepts. T2 - 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures CY - Potsdam, Germany DA - 27.08.2019 KW - Wood materials KW - Acoustic Emission KW - Structural integrity PY - 2019 AN - OPUS4-48802 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska A1 - Baer, Wolfram A1 - Wossidlo, Peter A1 - Habib, Abdel Karim T1 - Non-threshold acoustic emission analysis of damage evolution in pipe segments of steel S355J2H under bending load N2 - Four-point bending tests were carried out to analyze the acoustic characteristics of damage development in pipe segments made of steel, grade S355J2H, being 2.5 m long with an outer diameter of 168 mm and 16 mm wall thickness. To induce stable crack growth, the pipe segments were pre-damaged by a 90°circumferential notch in the middle of the pipe length. While the pipe was quasi-statically loaded, microscopic damage and plastic deformation accumulated to form a macroscopic crack that grew through the pipe wall until leakage. For acoustic emission (AE) monitoring, four broadband sensors of type VS 900 M were mounted close to the notch. Continuous AE signal detection was performed by the non-threshold method. Advantages and disadvantages of the non-threshold AE monitoring compared to a commonly employed method analyzing only signals exceeding a predefined threshold are discussed. The results of AE analysis are compared to additional information on the crack growth detected by the direct current potential drop (DCPD) technique. These studies were carried out in the course of the interdisciplinary research project AGIFAMOR, Ageing infrastructures - distributed acoustic monitoring of pipes at BAM. T2 - 33rd European Conference on Acoustic Emission Testing CY - Senlis, France DA - 12.09.2018 KW - Crack growth KW - Crack initiation KW - Four-point bending test KW - Steel pipe KW - Acoustic emission PY - 2018 AN - OPUS4-45964 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska A1 - Baer, Wolfram A1 - Chruscicki, Sebastian A1 - Habib, Abdel Karim A1 - Homann, Tobias A1 - Hussels, Maria-Teresa A1 - Prager, Jens A1 - Schmidt, Dirk A1 - Stajanca, Pavol A1 - Weltschev, Margit A1 - Wossidlo, Peter T1 - Feasibility study: Continuous monitoring of pipes using distributed acoustic and fibre optic sensors N2 - The feasibility study „AGIFAMOR. Ageing infrastructures – distributed acoustic monitoring of pipes” is an interdisciplinary research project at BAM internally financed from 2015 to 2018. Therefore, the quite young fibre optic sensing technology of distributed acoustic sensing (DAS) was investigated to possibly be extended towards a global condition monitoring system for pipelines operating in real time. DAS is a highly dynamic fibre optic sensing technology based on the method of coherent optical time domain reflectometry (C-OTDR). DAS allows capturing strain changes in the range of kHz. For the experimental work, the most suitable application yielding an optimum sensitivity was proven by wrapping a standard single-mode silica fibre around the pipe. The DAS sensitivity was investigated regarding the detection of 1) incidents that initiate propagation of acoustic waves in the pipe wall, 2) changes inside the pipeline causing altered flow and 3) damage development in the pipe wall. Therefore, several testing setups in laboratory as well as in real scale were realized. For comparison purposes, experiments were accompanied by acoustic emission analyses and by measurements with accelerometers. DAS was found to be very sensitive to gas ignition and its propagation across the pipe. Furthermore, the ability of DAS to detect and localize acoustic signals associated with pipeline leakage was demonstrated. The detection of crack formation and propagation within the pipe wall by means of DAS was studied during bending tests on several pipe segments, but was not proven so far with certainty. As expected, these studies turned out as the most difficult challenge due to the random occurrence and transient nature of microscopic damage phenomena. T2 - International Symposium on Structural Health Monitoring and Nondestructive Testing CY - Saarbrücken, Germany DA - 04.10.2018 KW - Fibre optic acoustic sensing KW - Continous monitoring KW - Acoustic emission KW - Accelerometers KW - Bending tests on pipe segments KW - Leak detection PY - 2018 AN - OPUS4-46200 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska T1 - Acoustic Emission T1 - Überwachung und Charakterisierung von Werkstoffen mittels Schallemissionsanalyse N2 - Das Phänomen Schallemission (eng. Acoustic Emission, AE) ist eine Begleiterscheinung bei aktiven Mechanismen und Prozessen wie sie in Werkstoffen auftreten, die einer Belastung durch Krafteinwirkung oder durch Änderung der Umgebungsbedingungen ausgesetzt sind. Plastische Verformung, Risswachstum, Korrosion oder der Übergang zu einer anderen Phase generieren u.a. transiente elastische Wellen, die sich im Werkstoff und an der Materialoberfläche ausbreiten. Auftretende Auslenkungen von wenigen hundert Pikometern sind mit piezo-elektrischen AE Sensoren detektierbar. Aufzeichnungsraten von bis zu 40 MHz ermöglichen dabei zeitliche Auflösungen von einigen Nano- bis Mikrosekunden. Die Dechiffrierung der detektierten Informationen ist für die Material- und Versagenscharakterisierung sowie für Anwendungen in der Struktur- oder Prozessüberwachung ein zentraler Forschungsschwerpunkt. Nach einem kurzen Überblick zu den Grundlagen werden ausgewählte Ansätze der AE Methode vorgestellt und diskutiert: 1) AE Monitoring von Pipelines als Referenzmessung für die Entwicklung eines akustischen faseroptischen Monitorings (AGIFAMOR) 2) Schwellwertfreie AE Messung im 4-Punkt-Rohrbiegeprüfstand BAM_9.1 (AGIFAMOR) 3) Kombination von AE mit Röntgen-Mikrotomografie und die Anwendung der frequenzbasierten Mustererkennung ermöglichen eine Zuordnung von AE und Mechanismen (Ergebnisse aus dem SNSF Projekt Nr. 127'134, Baensch 2014, Diss. ETH No. 22372) T2 - Abteilungsseminar BAM-8.1 CY - BAM UE, Berlin, Germany DA - 08.10.2018 KW - Acoustic Emission (AE) KW - Monitoring KW - Non-threshold measurement KW - Unsupervised pattern recognition PY - 2018 AN - OPUS4-46202 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska A1 - Baer, Wolfram A1 - Wossidlo, Peter A1 - Habib, Abdel Karim T1 - Frequenzanalyse von Schallemission an einem Stahlrohr unter Biegebeanspruchung N2 - Um ein tieferes Verständnis über die Schallemission bei der Entstehung und Ausbreitung von Rissen in Stahlrohrleitungen zu erlangen, wurde ein Stahlrohr der Güte S355J2H im Vierpunkt-Biegeversuch quasistatisch bis hin zum Wanddurchbruch (Leckage) belastet und mittels Schallemissionsmessung und Gleichstrompotentialmessung überwacht. Das Rohrsegment wurde durch einen 90°- Außenumfangskerb in der Mitte der Rohrlänge definiert vorgeschädigt, um davon ausgehend ein stabiles Risswachstum zu induzieren und die Analyse von Schallemission aus Rissereignissen, die am Kerb eintraten, sicherzustellen. Für die Schallemissionsmessung wurden vier Breitbandsensoren max. 105 mm vom Kerb entfernt montiert. Die Signalaufzeichnung erfolgte kontinuierlich und schwellwertunabhängig. Für die Gleichstrompotentialmessung wurde ein Gleichstrom von 300 A eingeleitet und der Potentialabfall über dem Kerb mit fünf Sonden entlang des Kerbs gemessen. Beide Messverfahren identifizieren die Rissinitiierung sowie Veränderungen im Risswachstum. Die detektierten Schallemissionsereignisse werden, unter Berücksichtigung spektraler Eigenschaften, mit fortschreitender Belastung und Rissentwicklung analysiert. Diese Studien wurden im Rahmen des interdisziplinären Forschungsprojekts AGIFAMOR, Aging infrastructure - Faseroptisches Monitoring von Rohrleitungen, an der BAM durchgeführt. T2 - 22. Kolloquium Schallemission und 3. Anwenderseminar Zustandsüberwachung mit geführten Wellen CY - Karlsruhe, Germany DA - 27.03.2019 KW - Schallemission KW - Frequenzanalyse KW - Rissbildung in Stahl PY - 2019 AN - OPUS4-47690 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Babutzka, Martin A1 - Trappe, Volker A1 - Pittner, Andreas A1 - Krankenhagen, Rainer A1 - Kühne, Hans-Carsten T1 - Vorstellung des Aktivitätsfelds Erneuerbare Energie N2 - Auf der Beiratssitzung des TF Energie wurde das Aktivitätsfeld Erneuerbare Energien in seinem breiten Spektrum (aber selektive Auswahl) vorgestellt. T2 - Beiratssitzung TF Energie CY - BAM Berlin-Adlershof, Germany DA - 09.04.2019 KW - Erneuerbare Energien KW - Windenergie PY - 2019 AN - OPUS4-47751 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartelmeß, Jürgen A1 - Gawlitza, Kornelia A1 - Tiebe, Carlo A1 - Bartholmai, Matthias A1 - Rurack, Knut T1 - Developments Towards a fluorometric sensing device for multiple hazardous gases N2 - Fluorometric sensing is a versatile approach for trace analysis outside of the laboratory, requiring suitable sensor materials and their integration into sensing devices. The versatility of fluorophores as probes, especially in terms of the possibility to tailor their optical as well as their recognition properties by synthetic modifications in a wide range, renders them as superior active component for the preparation of optical sensor devices. Recent works at BAM in this field include, for example, the detection of nerve gas agents,illustrating impressively the aforementioned benefits of fluorophores in optical sensing applications. In the interdisciplinary approach presented here, we target hazardous gases such as ammonia, benzene, and hydrogen sulfide, next to others, which pose a major threat to human health and environmental safety and for which the availability of a sensitive and reliable detection method is highly desirable. The dyes presented follow a “turn-on” fluorescence schematic, which allows for the selective and sensitive detection of the respective gaseous analyte. The immobilization of the probe in polymeric matrices is then the next step toward the fabrication of a prototype device for molecular sensing. Further steps in the project include the assembly of instruments for test-atmosphere generation, the referencing of the sensor system, development and implementation of an optical setup, and the testing of the prototype device under laboratory conditions and in the field. In this presentation, we give an overview over the recent developments on this topic in our groups, including fluorophore designs investigated for the detection of benzene, ammonia, and hydrogen sulfide as well as approaches for the design of the sensing device. T2 - EUROPT(R)ODE XIV CY - Neapel, Italy DA - 25.03.2018 KW - Gas sensor KW - Fluorometric sensing KW - BODIPY dye PY - 2018 AN - OPUS4-45645 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartelmeß, Jürgen A1 - Gawlitza, Kornelia A1 - Kraus, Werner A1 - Chlvi-Iborra, Katherine A1 - Tiebe, Carlo A1 - Noske, Reinhard A1 - Bartholmai, Matthias A1 - Rurack, Knut T1 - Developments Towards a BODIPY-based fluorometric sensing device for multiple hazardous gases N2 - Fluorometric sensing is a versatile approach for trace analysis outside of the laboratory, requiring suitable sensor materials and their integration into sensing devices. The versatility of fluorophores as probes, especially in terms of the possibility to tailor their optical as well as their recognition properties by synthetic modifications in a wide range, renders them as superior active component for the preparation of optical sensing devices. Recent works at BAM in this field include, for example, the detection of nerve gas agents, illustrating impressively the aforementioned benefits of fluorophores in optical sensing applications. In the interdisciplinary project presented here, we target hazardous gases such as ammonia, benzene, and hydrogen sulfide, next to others, which pose a major threat to human health and environmental safety and for which the availability of a sensitive and reliable detection method is highly desirable. The dyes presented follow a “turn-on” fluorescence schematic, which allows for the selective and sensitive detection of the respective gaseous analyte. The immobilization of the probe in polymeric matrices is then the next step toward the fabrication of a prototype device for molecular sensing. Further steps in the project include the assembly of instruments for test-atmosphere generation, the referencing of the sensor system, development and implementation of an optical setup, and the testing of the prototype device under laboratory conditions and in the field. In this presentation, we give an overview over the recent developments on this topic in our groups. Highlights are hydrogen sulfide sensitive, BODIPY based transition metal complexes, which allow for a sensitive as well as selective detection of the toxic gas. In addition, we present a novel class of highly substituted BODIPY derivatives – pocket-BODIPYs – which are of a synthetically high versatility and can readily be modified to create pockets in the periphery of the molecule of defined geometries. This is illustrated on the successful encapsulation of benzene by a pocket-BODIPY derivative, confirmed by X-ray crystallographic analysis as well as by further spectroscopic and analytical methods. T2 - International Conference on Porphyrins and Phthalocyanins (ICPP-10) CY - Munich, Germany DA - 01.07.2018 KW - BODIPY dye KW - Fluorometric sensing KW - Gas sensing PY - 2018 AN - OPUS4-45646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Schütze, A. T1 - Sensor network deployment N2 - Content • Fixed monitoring stations • Mobile monitoring stations (on trams, buses, cars) • Personal mobile monitoring systems • Environmental monitoring for agriculture and beyond • Sensors on flying platforms T2 - Networked Environmental Monitoring – from sensor principles to novel services CY - BAM, Berlin, Germany DA - 06.02.2018 KW - Environmental monitoring KW - Gas sensors PY - 2018 AN - OPUS4-44073 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Tiebe, Carlo A1 - Neumann, Patrick P. T1 - Two tasks in environmental monitoring - calibration and characterization of gas sensors and remote gas sensing with multicopter platforms - Part 1 N2 - Leaking methane from infrastructures, such as pipelines and landfills, is critical for the environment but can also pose a safety risk. To enable a fast detection and localization of these kind of leaks, BAM developed a novel robotic platform for aerial remote gas sensing. Spectroscopic measurement methods for remote sensing of selected gases lend themselves for use on mini-copters, which offer a number of advantages for inspection and surveillance over traditional methods. No direct contact with the target gas is needed and thus the influence of the copter downwash on the measured gas plume can be kept to a minimum. This allows to overcome one of the major issues with gas-sensitive mini-copters. On the other hand, remote gas sensors, most prominently Tunable Diode Laser Absorption Spectroscopy (TDLAS) sensors have been too bulky given the payload and energy restrictions of mini-copters. Here, we present the Unmanned Aerial Vehicle for Remote Gas Sensing (UAV-REGAS), which combines a novel lightweight TDLAS sensor with a 3-axis aerial stabilization gimbal for aiming on a versatile multicopter. The proposed system can be deployed in scenarios that cannot be addressed by currently available systems and thus constitutes a significant step forward for the field of Mobile Robot Olfaction (MRO). It enables tomographic reconstruction of gas plumes and a localization of gas sources. We also present first results showing its performance under realistic conditions. T2 - Aarhus University, Department of Environmental Science, External seminar with Matthias Bartholmai and Carlo Tiebe CY - Roskilde, Denmark DA - 29.08.2018 KW - Environmental monitoring KW - Remote gas sensing KW - Flying platforms KW - Mobile robot olfaction KW - UAS PY - 2018 AN - OPUS4-45838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd A1 - Zia, Ghezal-Ahmed A1 - Schilling, Markus A1 - Skrotzki, Birgit A1 - von Hartrott, P. A1 - Hanke, T. A1 - Waitelonis, J. T1 - Towards Interoperability: Digital Representation of a Material Specific Characterization Method N2 - Certain metallic materials gain better mechanical properties through controlled heat treatments. For example, in age-hardenable aluminum alloys, the strengthening mechanism is based on the controlled formation of nanometer sized precipitates, which represent obstacles to dislocation movement. Precise tuning of the material structure is critical for optimal mechanical behavior in the application. Therefore, analysis of the microstructure and especially the precipitates is essential to determine the ideal parameters for the interplay of material and heat treatment. Transmission electron microscopy (TEM) is utilized to identify precipitate types and orientations in a first step. Dark-field imaging (DF-TEM) is often used to image the precipitates and to quantify their relevant dimensions. The present work aims at the digital representation of this material-specific characterization method. Instead of a time-consuming, manual image analysis, an automatable, digital approach is demonstrated. Based on DF-TEM images of different precipitation states of a wrought aluminum alloy, a modularizable digital workflow for quantitative precipitation analysis is presented. The integration of this workflow into a data pipeline concept will also be discussed. Thus, by using ontologies, the raw image data, their respective contextual information, and the resulting output data from the quantitative precipitation analysis can be linked in a triplestore. Publishing the digital workflow and the ontologies will ensure the reproducibility of the data. In addition, the semantic structure enables data sharing and reuse for other applications and purposes, demonstrating interoperability. The presented work is part of two digitization initiatives, the Platform MaterialDigital (PMD, materialdigital.de) and Materials-open-Laboratory (Mat-o-Lab). T2 - MSE 2022 CY - Darmstadt, Germany DA - 27.09.2022 KW - Interoperability KW - Ontology KW - Precipitation Analysis PY - 2022 AN - OPUS4-55892 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Mitzkus, Anja A1 - Sahre, Mario A1 - Lange, Thorid A1 - Weise, Matthias A1 - Bartholmai, Matthias A1 - Schukar, Vivien A1 - Basedau, Frank A1 - Hofman, Detlef A1 - Köppe, Enrico T1 - From on line sensor validation to in-situ monitoring of layer growth: coatings around fibre bragg gratings N2 - The lack of on-line validation procedures for structure-embedded fiber-optical strain sensors, in particular fiber-Bragg-gratings (FBG), resulted in limited applications in structural health monitoring (SHM). Degradation under service conditions and ageing as a result of climatic influences or delamination under load were unsolved Validation issues. This could be overcome by means of an auto-diagnosis procedure based on FBG-sensors coated by electrochemical deposition (ECD) with a magnetostrictive NiFe-coating on top of an adhesive Cu/Cr adhesive layer deposited by physical vapour deposition (PVD) around the FBG strain sensor. This allows at any time under Service a validation of sensor functionality, stability, and reliability. For this purpose, a magnetic strain-proportional reference field is introduced. The optical read-out is realized by the measurement of the Bragg-wavelength shift. The ratio of resulting strain and exciting magnetic reference field should be constant given that the sensor is in proper function. In principle, the magnetostrictive coating around the FBG should also work as on-line magnetic field sensor and other applications in material science. One of these applications is the in-situ monitoring of ECD processes as the deposition of the ECD NiFe-layer on the FBG revealed. Challenges are the monitoring of temperature, deposition stages/thickness, and resulting mechanical stress under given plating conditions. Monitoring problems can be solved by applying a pre-coated FBG to the electrolytic process as the shift of the Bragg wavelength is affected by both the temperature of the electrolyte near the substrate and the stress formation in the growing layer. The experimental FBG set-up and the quantitative determination of temperature- and stress-related strain are described for a nickeliron electrolyte. The in-situ measurement of Bragg wavelength shifts of a pre-coated FBG during electrochemical deposition allows a detailed analysis of stress states due to changes in the growth morphology of the layer. The separation of mechanical and thermal contributions to this shift provides information on the individual Deposition processes in terms of a process fingerprint. T2 - ICMCTF 2021 San Diego/on-line CY - Online meeting DA - 28.04.2021 KW - Fiber- Bragg-gratings (FBG) KW - Physical vapour deposition (PVD) KW - Electrochemical deposition (ECD) KW - Magnetostrictive coating KW - ECD NiFe-layer PY - 2021 AN - OPUS4-52898 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Mitzkus, Anja A1 - Sahre, Mario A1 - Weise, Matthias A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Basedau, Frank A1 - Hofmann, Detlef A1 - Schukar, Vivien T1 - Faser-basierter magneto-optischer Schicht-Sensor zum Monitoring von Bauteilen N2 - In Glasfasern eingeschriebene Bragg-Gitter (FBG: fibre-based Bragg gratings) sind über die Verschiebung der Bragg-Wellenlänge in der Lage, Stauchungen und Dehnungen von Glasfasern hochgenau zu erfassen. In Kompositwerkstoffe eingebettete faseroptische Sensoren können Bauteile bezüglich ihrer mechanischen Integrität überwachen und früh-zeitig Informationen über Materialveränderungen gewinnen. Um die Zuverlässigkeit eines solchen Sensors zu gewährleisten, ist es wichtig, die korrekte Funktion des Sensors im Verbund mit der Werkstoff-Matrix on-line und in-situ sicherzu-stellen. Im Rahmen des DFG-Projekts FAMOS² (FAser-basierter Magneto-Optischer SchichtSensor) wurde ein selbstdiagnosefähiger Schichtsensor entwickelt, der mit Hilfe von magnetostriktiven Aktorschichten aus Nickel bzw. Eisen-Nickel validiert werden kann. Der FAMOS²-Schichtsensor wird durch ein PVD (physical vapour deposition)/ECD (electro-chemical deposition) Hybridschichtsystem realisiert, das auf dem Fasermantel im Bereich des FBG haftfest, homogen und langzeitfunktional abzuscheiden ist. Dabei wird in einem ersten Schritt ein etwa 100 Nanometer dünnes PVD-Schichtsystem aus Chrom und Kupfer als Haftvermittler auf der Glasfaser bzw. als leitfähige Startschicht für den nachfolgenden ECD-Prozess abgeschieden. Um eine rotationssymmetrische Schich-tabscheidung zu gewährleisten, erfolgt während der PVD-Beschichtung eine Rotation der Glasfasern. In einem zweiten Schritt wird dann unter Verwendung eines klassischen Watts-Elektrolyten in einer speziell entwickelten ebenfalls rotationssymmetrisch aufgebau-ten ECD-Durchströmungszelle dann die etwa 30 Mikrometer dicke, magnetostriktive Ak-torschicht auf dem PVD-Schichtsystem abgeschieden, im Vergleich sowohl reine Nickel-Schichten als auch Nickel-Eisen-Schichten. Ein äußeres Magnetfeld dehnt die magnetostriktive Aktorschicht und damit auch die Faser reversibel. Diese Dehnung führt zu einer Verschiebung der Bragg-Wellenlänge, welche direkt mit der Stärke eines zu messenden oder zu Validierungszwecken vorgegebenen Magnetfeldes korreliert. Die Anpassung der Beschichtungsverfahren an die Fasergeome-trie und die mechanischen Eigenschaften der Hybridschichten werden hinsichtlich der me-chanischen Integrität des faseroptischen Sensors diskutiert und der Nachweis der Selbst-diagnosefähigkeit erbracht. T2 - 13. ThGOT Thementage Grenz- und Oberflächentechnik und 11. Thüringer Biomaterial-Kolloquium CY - Zeulenroda, Germany DA - 13.03.2018 KW - Magneto-optischer Sensor KW - Faser-Bragg Gitter KW - Magnetostriktive Beschichtung KW - Selbstkalibrierung KW - Bauteilmonitoring PY - 2018 AN - OPUS4-44598 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Fischer, Daniel A1 - Hertwig, Andreas A1 - Mitzkus, Anja A1 - Sahre, Mario A1 - Weise, Matthias A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Basedau, Frank A1 - Hofmann, Detlef A1 - Schukar, Vivien A1 - Kormunda2, M. T1 - Multi-functional coatings for optical sensor applications: Surface plasmon resonance & magneto-optical coupling N2 - Multi-functional coatings are a key requirement for surface engineering. General demands are adhesion and long-term stability under service conditions. The modification of surfaces by means of PVD-, ECD- or hybrid processes allows an add-on functionalization of surfaces by a huge diversity of materials with both lateral and vertical micro-/nano-designs. This fact is a prerequisite for micro- and sensor-systems in lab-on-chip and sensor-on-chip technology. Two layer-based sensor principles are presented, i.e. surface plasmon resonance enhanced spectroscopic ellipsometry (SPREE) for detection of hazardous gases and magneto-optical sensors on smart-coated fiber Bragg gratings (FBG) for structural health monitoring (SHM). The interdependence of substrate features, coating properties, and layer design is discussed firstly for gas sensitivity and selectivity of SPREE-sensors and secondly for sensitivity and selectivity of magneto-strictive coatings to mechanical strain or external magnetic fields resulting in an optical displacement of the Bragg wavelength of FBG-sensors. Moreover, generic features such long-term stability, crucial process-related fabrication conditions, and effects of operational and environmental parameters are discussed with respect to the sensor performance. It has been shown that appropriate layer design and adapted selection of layer materials (SnOx/Au, Fe/Ni:SnOx/Au; Ni/NiFe-Cu-Cr) result in improved sensor parameters and may enable new sensor applications. T2 - SVC TechCon 2018 CY - Orlando, FL, USA DA - 05.05.2018 KW - Multi-functional coatings for sensors KW - Surface plasmon resonance enhanced ellipsometry (SPREE) KW - Gas monitoring KW - Magneto-optical coupling (MOC) KW - Structural health monitoring (SHM) PY - 2018 AN - OPUS4-44976 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Tina A1 - Altenburg, Simon A1 - Metz, Christian A1 - Breese, Philipp Peter A1 - Oster, Simon A1 - Maierhofer, Christiane T1 - Two approaches for multi measurand in-situ monitoring of the L-PBF process – bicolor- and RGB-optical tomography N2 - Since metal additive manufacturing (AM) becomes more and more established in industry, also the cost pressure for AM components increases. One big cost factor is the quality control of the manufactured components. Reliable in-process monitoring systems are a promising route to lower scrap rates and enhance trust in the component and process quality. The focus of this contribution is the presentation and comparison of two optical tomography based multi measurand in-situ monitoring approaches for the L-PBF process: the bicolor- and the RGB-optical tomography. The classical optical tomography (OT) is one of the most common commercial in-situ monitoring techniques in industrial L-PBF machines. In the OT spatial resolved layer-images of the L-PBF process are taken from an off-axis position in one near infrared wavelength window. In addition to the explanatory powers classical OT, both here presented approaches enable the determination of the maximum surface temperature. In contrast to thermography that may also yield maximum temperature information, the needed equipment is significantly cheaper and offers a higher spatial resolution. Both approaches are implemented at a new in-house developed L-PBF system (Sensor-based additive manufacturing machine - SAMMIE). SAMMIE is specifically designed for the development and characterization of in-situ monitoring systems and is introduced as well. T2 - ICAM2022 CY - Orlando, FL, USA DA - 31.10.2022 KW - Additive Manufacturing KW - L-PBF KW - In-process monitoring KW - Optical tomography PY - 2022 AN - OPUS4-56594 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Tina A1 - Altenburg, Simon A1 - Scheuschner, Nils A1 - Maierhofer, Christiane T1 - Multi measurand in-situ monitoring of the laser powder bed fusion process by means of multispectral optical tomography N2 - Laser Powder Bed Fusion (L-PBF), as one of the most promising production process in the field of metal additive manufacturing, enables traditional constructive solutions to be rethought and the manufacturing of optimized components according to the "form follows function" principle. The most significant obstacle for a broad industrial application of the L-PBF process is the inadequate quality assurance during the manufacturing process so far, leading to high production costs. Although several mainly camera based commercial in-process monitoring systems are already available, a deep understanding of the interpretation of the monitored data and correlation with actual defects is still lacking. One reason for this is the reduction of the complex process signature to just one measurement value. The focus of this contribution is the presentation of the multispectral optical tomography as alternative to single measurand in-situ monitoring systems. The potential of this approach is hereby shown on L-PBF printed samples with induced process instabilities. Beyond that, an in-house developed L-PBF printer for further testing of multi-sensor in-situ monitoring systems is presented. T2 - ICAM2021 CY - Online meeting DA - 01.11.2021 KW - In-situ monitoring KW - L-PBF KW - Optical tomography KW - 3d printing KW - Thermography PY - 2021 AN - OPUS4-54388 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Spranger, Holger T1 - Optischer Ansatz zur Bestimmung von Materialeigenschaften und Schichtstrukturen N2 - THz-TDS Systeme können zeitaufgelöst die Amplitude der elektrischen Feldstärke E(t) detektieren. Der Vorteil des verwendeten Messprinzips besteht in dem gleichzeitigen Nachweis von Amplitude und Phase des zwischen der Antenne und dem Detektor sich ausbreitenden elektrischen Feldes eines Impulses. Befindet sich im Strahlengang dielektrisches Material, dann ändern sich die Laufzeit (Time of Flight) und Amplitude des Impulses im Vergleich zum freien Strahlengang. Planare Fehlstellen, wie Risse oder delaminierte Schichten in Kompositen sowie mehrschichtig aufgebaute Dielektrika können als optische Mehrschichtsysteme aufgefasst werden, mit denen sich die beobachteten Transmissions- und Reflektionseigenschaften im THz-Bereich erklären lassen. Bei Entwicklung eines optischen Schichtenmodells für das jeweilig ausgewählte Schichtensystem lassen sich zeitliche Impulsverläufe in Abhängigkeit von der Schichtenfolge- und deren –dicke berechnen. Durch den Fit der experimentell gewonnener Daten mit den aus dem Schichtenmodell berechneten Impulssequenzen lassen sich unter Verwendung der Methode der kleinsten Quadrate Schichtdicken oder die Brechungsindizes der einzelnen Schichten im jeweiligen Testobjekt bestimmen. Anhand eines repräsentativen Beispiels wird die Entwicklung des Schichtenmodells erklärt und die erreichten Genauigkeiten zur Bestimmung der Schichtdicken und Brechungsindizes anhand selbst entwickelter Testkörper diskutiert. T2 - Workshop „Wertschöpfungspotential der neuen Mikrowellen- und Terahertz-Sensorik in der Kunststoffindustrie" CY - Würzburg, Germany DA - 07.11.2018 KW - Dickenmessung, KW - Zeitaufgelöste THz-Spektroskopie PY - 2018 AN - OPUS4-46629 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Spranger, Holger T1 - Hat die Nutzung der Terahertz-Strahlung eine Zukunft in der Zerstörungsfreien Prüfung? N2 - Die zeitaufgelöste THz-Spektroskopie (THz-TDS) ist eine relativ junge Technologie, die im Bereich der Zerstörungsfreien Werkstoffprüfung (ZfP) seit einiger Zeit genutzt wird. Es werden die neusten Entwicklungen in Verbindung mit deren Perspektiven in der ZfP vorgestellt und diskutiert. T2 - DGZfP Arbeitskreis Zwickau-Chemnitz CY - Ackerbürgersaal am Kornmarkt 5, Zwickau, Germany DA - 16.10.2018 KW - Zeitaufgelöste THz Spektroskopie KW - ZfP 4.0 PY - 2018 AN - OPUS4-46637 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Bär, Sylke A1 - Spranger, Holger T1 - Synthetische Aperturfokussierung für die Terahertzspektroskopie N2 - Die zeitaufgelöste THz-Spektroskopie (THz-TDS) operiert mit elektromagnetischen Impulsen, die ein Amplitudenspektrum im unteren THz-Bereich aufweisen. Die THz-TDS ist in der Lage, dielektrische Volumina zerstörungs- und kontaktfreie zu durchstrahlen. Um eine 3D-THz Bildung zu ermöglichen, wurde für die THz-TDS ein rechnergestütztes Mess- und Rekonstruktionsverfahren (THz-TD-SAFT) entwickelt, mit dem es gelingt, unter Verwendung der im Zeitbereich registrierten THz-TDS-Daten das Volumeninnere in Form eines dreidimensionalen Tomogramms zu rekonstruieren. Die THz-TD-SAFT basiert auf die für die Ultraschalltechnik entwickelte Synthetische Apertur Fokussierung (SAFT) bzw. des heuristisch begründeten Algorithmus des Synthetischen Apertur Radars (SAR). Anhand von Beispielen wird die Möglichkeiten der THz-TD-SAFT demonstriert und nachgewiesen, dass mit dem Rekonstruktionsansatz die künstlich eingebauten Fehlstellen bezüglich der Position und Größe geometrisch richtig im Tomogramm abgebildet werden können. T2 - 4. Fachseminar, Mikrowellen- und Terahertz-Prüftechnik in der Praxis CY - Fürth, Germany DA - 02.04.2019 KW - Zeitaufgelöste THz-Spektroskopie KW - THz-TD-SAFT KW - THz-Tommographie PY - 2019 AN - OPUS4-47756 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten T1 - Virtual CT with aRTist N2 - Simulation becomes more and more important in modern CT imaging. It is increasingly used to optimize techniques for complex applications, to support the preparation of written procedures, and for educational purposes. The radiographic simulator aRTist is a modelling tool which simulates X-ray imaging using a hybrid analytical and Monte Carlo method to efficiently model the radiation transport. In addition to the relevant physical effects such as absorption, scattering and fluorescence, simplified fast models are employed to describe the characteristics of the X-ray source and the detector. aRTist is well equipped to model realistic X-ray imaging setups due to the ability to load exported CAD object descriptions. A simple CT scan module is contained in aRTist which allows the simulation of standard (circular cone beam) scanning trajectories. This training session starts with a general introduction to aRTist and will highlight its basic usage. Furthermore, the focus is on the configuration of scan trajectories and batch simulations for virtual CT. The aim is to enable the audience to use the aRTist software for their own experiments in virtual CT. T2 - dXCT conference 2021 CY - Online meeting DA - 17.05.2021 KW - computed tomography simulation PY - 2021 AN - OPUS4-54062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten A1 - Evsevleev, Sergei A1 - Plotzki, David T1 - AdvanCT Virtual CT N2 - Simulation becomes more and more important in modern CT imaging. It is increasingly used to optimize techniques for complex applications, and for educational purposes. Simulation can also be used for uncertainty estimation of dimensional CT measurements. The radiographic simulator aRTist is a modelling tool which simulates X-ray imaging using a hybrid analytical and Monte-Carlo method to efficiently model the radiation transport. In addition to the relevant physical effects such as absorption and scattering, simplified fast models are employed to describe the characteristics of the X-ray source and the detector. aRTist is well equipped to model realistic X-ray imaging setups due to the ability to load exported CAD object descriptions. By repetitive simulation runs aRTist can function as virtual CT device. A simple CT scan module is contained in aRTist which allows the simulation of standard (circular cone beam) scanning trajectories. AdvanCT is a module for aRTist which allows to set up more complex scanning trajectories by attaching geometrical modification functions to the objects in the radiographic scene. In this way, advanced scanning modes can be realized. In addition to deterministic motion, also random variations can be introduced. By combining random variations with deterministic motion, non-ideal (realistic) CT scan geometries can be simulated, e.g. focal spot drift and mechanical instability of the axis of rotation. The AdvanCT module conveniently allows to construct these scenarios in a graphical interface and provides a preview before starting the (potentially long running) batch job. Therefore, deviations from ideal CT scan trajectories can be easily adjusted which is a necessary step towards uncertainty determination from simulation. T2 - dXCT conference 2021 CY - Online meeting DA - 17.05.2021 KW - X-ray Virtual Computer Tomography Simulation PY - 2021 AN - OPUS4-52953 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten T1 - Virtual CT with Complex scanning trajectories in aRTist N2 - The simulator aRTist combines analytical and Monte Carlo methods to efficiently model the radiographic process of industrial radiology. In this contribution we focus on virtual computer tomography, the simulation of tomographic scans. The possibilities to simulate complex scanning trajectories are shown in combination with the tomographic reconstruction using individual projection matrices. T2 - The 4th Annual Advances in X-Ray Imaging Workshop CY - Diamond Light Source, Didcot, UK DA - 11.06.2019 KW - X-ray Computer-tomography simulation PY - 2019 AN - OPUS4-48297 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten A1 - Burger, Karin A1 - Gollwitzer, Christian T1 - Virtual CT acquisition and reconstruction of complex and noisy scanning trajectories in aRTist N2 - In modern CT imaging, simulation has become an important tool to minimize cost- and time-intensive measurements. It is increasingly used to optimize techniques for complex applications, to support the preparation of written procedures, and for educational purposes. We extended the CT simulation software ‘aRTist’ with a module to set-up arbitrary trajectories including disturbing influences during the scan. Moreover, such geometric deviations can be compensated by the internal reconstruction tool. T2 - 9th Conference on Industrial Computed Tomography (iCT) CY - Padua, Italy DA - 13.02.2019 KW - Simulation KW - Arbitrary trajectories KW - Projection matrix KW - Filtered back projection PY - 2019 AN - OPUS4-47476 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten A1 - Bartscher, M. A1 - Borges de Oliveira, F. A1 - Hausotte, T. A1 - Kasperl, S. A1 - Reuter, T. A1 - Schielein, R. T1 - Realistic Simulation of CT Systems - An Introduction to The CTSimU2 Project N2 - The project series CTSimU was initiated with the goal to develop a set of procedures to enable the determination of the task-specific measurement uncertainty of a CT system numerically by radiographic simulation. The first project (2019-2022) “Radiographic Computed Tomography Simulation for Measurement Uncertainty Evaluation - CTSimU” was focused on the sufficient physical correctness of the radiographic simulation and created as a result a test framework for simulation softwares and a draft of a VDI standard in the series VDI/VDE 2630 for this application. However, for the realistic simulation of a CT system in a simulation software (i.e. a digital twin), not only the correctness of the simulation software itself is crucial, but also the quality of the parameterization of the CT system in the simulation software - this represents the starting point of the 2nd project “Realistic Simulation of real CT systems with a basic-qualified Simulation Software - CTSimU2” (2022-2024). The parameterization of a CT system in a simulation software can be divided into four steps: after the data acquisition at the real CT system (step 1) follows the evaluation of the acquired data for the generation of general parameter specifications (step 2). It follows the transfer of the parameters into the specific simulation software (step 3) and the validation of the resulting simulation parameters by a suitable test (step 4). The intended result of the project CTSimU2 is a draft VDI standard (for VDI/VDE 2630) for this test, which contains an informative annex on the state of the art regarding the possibilities for parameter determination. T2 - 13th European Conference on Non-Destructive Testing (ECNDT) CY - Lisbon, Portugal DA - 03.07.2023 KW - X-ray computed tomography KW - dXCT KW - Simulation PY - 2023 AN - OPUS4-58923 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bente, Klaas A1 - Oeff, J. A1 - Gaal, Mate T1 - Quantitative, zeiteffiziente, winkel- und frequenzaufgelöste Analyse von Elektretwandlern im Hör- und Ultraschallbereich N2 - Elektretwandler sind sensitive und immer verschleißresistentere Schallwandler, wodurch sie verbreitet Einsatz im Hör- und Ultraschallbereich finden. Geladene, zelluläre Polypropylen-Folien eignen sich besonders gut als Wandlermaterial aufgrund ihrer, verglichen mit Piezokompositen, hundertfach niedrigeren akustischen Impedanz bei gleichem piezoelektrischem Koeffizienten. Doch das winkel- und frequenzabhängige Verhalten der Wandler ist kaum untersucht und wenig quantifiziert. In dieser Arbeit wird gezeigt, dass diese Folien eine schichtdickenabhängige Sensitivität zwischen 0.1 mV/Pa und 10 mV/Pa aufwiesen. Ein Maximum in der Sensitivität fand sich nahe ihrer mechanischen Resonanzfrequenz im Ultraschallbereich, aber auch im niederfrequenten Hörschallbereich. Darüber hinaus konnte die Winkelabhängigkeit der Sensitivität charakterisiert werden. Die Analyse konnte dabei zeiteffizient mit einem breitbandig emittierenden, thermoakustischen Wandler umgesetzt werden, sodass pro Winkel eine Messung für die Berechnung der Übertragungsfunktion des Wandlers genügte. Quantifiziert wurden die Ergebnisse durch das einmalige Vermessen des Schallfeldes des Emitters mittels Laser-Doppler-Vibrometrie. Mit den erzielten Ergebnissen wurde zum einen das komplexe Sensitivitätsverhalten der Wandler untersucht, aber auch eine grundlegende Methodik aufgezeigt, wie Wandler quantitativ, multivariat charakterisiert werden können. Winkel- und frequenzaufgelöste Sensitivitäten erlauben zum einen die Analyse der Anwendbarkeit der Wandler für sämtliche Einsatzgebiete, zum anderen stehen so Rückschlüsse über die mechanische Dynamik von Elektretfolien in Aussicht, da deren Sensitivität direkt mit ihrem Elastizitätsmodul skaliert. T2 - DAGA 2019 CY - Rostock, Germany DA - 18.03.2019 KW - Luftultraschall KW - Ultraschall KW - Elektretwandler KW - Thermoakustik KW - Wandlercharakterisierung PY - 2019 AN - OPUS4-47597 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bernard, D. A1 - Léonard, Fabien A1 - Plougonven, E. A1 - Bruno, Giovanni T1 - On the use of autocorrelation functions, permeability tensors, and computed tomography to characterize the anisotropy of Diesel particulate filter materials N2 - 3D images such as those produces by X-ray tomography can provide a wealth of information on the internal structure of materials, but quantification of specific geometrical or topological characteristics linked to some bulk physical property is far from being straightforward. This study focuses on methods to quantify the differences in physical properties as a function of direction, i.e. their anisotropy, and how it can be linked to measures of anisotropy of the internal structure of the material. The auto-correlation function gives a similarity measure in the volume as a function of distance and direction. This is a cross-correlation of the image with itself fast to compute and relatively insensitive to noise. It is why we focus on this method to compare with the physical property of our DPF material. Diesel Particulate Filter (DPF) materials are porous ceramics that; a) can be used at very high temperatures; b) have very good thermal shock resistance; c) are inert; d) can be manufactured with tailored porosity. Their usual way of production consists of the extrusion of a slurry into the desired filter shape, with successive ceramming at high temperature. This process causes anisotropy at both microscopic and macroscopic levels. T2 - ICTMS 2019 CY - Cairns, Australia DA - 22.07.2019 KW - Structure-property relationship KW - Anisotropy estimate KW - Porous ceramics KW - Autocorrelation PY - 2019 AN - OPUS4-49226 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bernegger, Raphael A1 - Altenburg, Simon A1 - Maierhofer, Christiane T1 - Numerical 2D model to quantify defects in semitransparent materials by pulsed thermography N2 - Pulsed thermography is a well-known non-destructive testing technique and has proven to be a valuable tool for evaluation of material defects. Material defects are often simulated by flat-bottom holes (FBH) or grooves. Typically, analytical 1D models are used to determine the defect depth of FBHs, grooves or delaminations. However, these models cannot take into account lateral heat flows, or only to a limited extent (semi-empirical model). Their applicability is therefore limited by the FBHs aspect ratio (diameter to remaining wall thickness), to ensure that the heat flow above the defect can still be described one-dimensionally. Additionally, the surfaces of semi-transparent materials have to be blackened to absorb the radiation energy on the surface of the material. Without surface coatings, these models cannot be used for semi-transparent materials. Available 1D analytical models for determination of sample or layer thicknesses also do not take into account lateral heat flows. Here, we present an approach for quantitative determination of the geometry of FBHs or grooves in semi-transparent materials by considering lateral heat flow. For this purpose, the results of a numerical 2D model are fitted to experimental data, e.g., to determine simultaneously the defect depth of a FBH or groove and its diameter or width, respectively. The model considers semi-transparency of the sample within the wavelength range of the excitation source as well as of the IR camera and thermal losses at its surfaces. Heat transport by radiation within the sample is neglected. It supports the use of an arbitrary temporal shape of the heating pulse to properly describe the measurement conditions for different heat sources. T2 - Progress in Photoacoustic & Photothermal Phenomena CY - Erice, Italy DA - 06.09.2018 KW - Pulse thermography KW - Numerical modelling KW - 2D model KW - Data reconstruction KW - Flat bottom holes KW - Notches KW - Semitrasnparent materials PY - 2018 AN - OPUS4-46105 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bernegger, Raphael A1 - Altenburg, Simon A1 - Maierhofer, Christiane T1 - Iterative numerical 2D-modeling for quantification of material defects by pulsed thermography N2 - Pulsed thermography is a well-known non-destructive testing technique and has proven to be a valuable tool for examination of material defects. Typically, analytical 1D models are used to determine the defect depth of flat-bottom holes (FBH), grooves or delamination. However, these models cannot take into account lateral heat flows, or only to a limited extent. They are therefore limited by the FBHs aspect ratio (diameter to remaining wall thickness), to ensure that the heat flow above the defect can still be described one-dimensionally. Here, we present an approach for quantitative determination of the geometry for FBH or grooves. For this purpose, the results of a numerical 2D model are fitted to experimental data, e.g., to determine simultaneously the defect depth of a groove or FBH and its diameter of width. The model takes lateral heat flows into account as well as thermal losses. Figure 1 shows the temperature increase of a pulsed thermography measurement at three different locations on the sample. The numerical model is fitted to the experimental data (red lines) to quantify the groove. The numerical simulation matches the experimental data well. T2 - 45th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Burlington, VT, USA DA - 15.07.2018 KW - Opaque materials KW - Pulse thermography KW - Numerical modelling KW - 2D model KW - Data reconstruction KW - Flat bottom holes KW - Notches PY - 2018 AN - OPUS4-46353 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bernegger, Raphael A1 - Altenburg, Simon A1 - Maierhofer, Christiane T1 - Pulsed thermography on semitransparent materials - what has to be considered? N2 - Pulsed thermography is a well-known non-destructive testing technique and has proven to be a valuable tool for examination of material defects, to determine thermal material parameters, and the thickness of test specimens through calibration or mathematical models. However, the application to semitransparent materials is quite new and demanding, especially for semitransparent materials like epoxy, polyamide 12, or glass fiber reinforced polymers with epoxy or polyamide matrix. In order to describe the temporal temperature evolution in such materials, which are recorded with an infrared camera during pulse thermography experiments, much more influences have to be considered, compared to opaque materials: - The wavelength of the excitation source and the spectral range of the infrared camera - The angles between the specimen, the excitation source and the infrared camera - The area behind the specimen - The roughness of the material surface - The scattering mechanism within the material Here, we will consider all these influences and describe how they can be treated mathematically in analytical or numerical models (using COMSOL Multiphysics software). These models describe the temperature development during the pulse thermography experiment in reflection and transmission configuration. By fitting the results of the mathematical models to experimental data it is possible to determine the thickness or the optical and thermal properties of the specimen. T2 - 20-th International Conference on Photoacoustic and Photothermal Phenomena CY - Moscow, Russia DA - 07.07.2019 KW - Numerical simulation KW - Pulsed thermography KW - Semitransparent KW - Analytical model KW - Delamination KW - GFRP PY - 2019 AN - OPUS4-49215 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija T1 - The Past and the Future of Human Factors: The “Uncontrollable” Aspect of NDT Reliability? N2 - That human factors (HF) affect the reliability of NDT is not novelty. Still, when it comes to reliability assessments, the role of people is often neglected. Reliability is typically expressed in terms of POD curves, and the effects of human and organisational factors on the inspection are typically tackled by the regulations, procedures and by the qualification and training of the inspection personnel. However, studies have shown that even the most experienced personnel can make mistakes and that the reliability in the field is never as high as the reliability measured in the POD experiments. Generally, HF are considered too unpredictable and too uncontrollable to model. If that is the fact, then what can we do? The engineering perspective to this problem has often been to find ways to automate inspections and, recently, to make use of artificial intelligence tools to decrease the direct effect of people on the inspection results and improve the overall efficiency and reliability. However, despite automation and AI, people remain the key players, though their tasks change. The contemporary approach to HF is not to engineer them out of the system but to design human-machine systems that make the best use of both. In this talk, ways of tackling HF in the design of systems and processes will be presented. T2 - Reliability of NDT webinar, The Scottish Branch of the British Institute of NDT CY - Online meeting DA - 29.01.2021 KW - Non-Destructive Testing KW - NDT KW - Human Factors KW - Reliability PY - 2021 UR - www.bindt.org/admin/Downloads/2021-01%20BINDT_Bertovic_Human%20factors_new.pdf AN - OPUS4-53544 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija A1 - Virkkunen, I. T1 - NDE 4.0: Redefining Traditional Inspector Roles N2 - The successful shift to NDE 4.0 will not only require developing and embracing new technologies associated with the fourth industrial revolution or becoming an integral part of the overall Industry 4.0, but also developing and adopting new ways of working. It is undoubtful that people will remain in charge of the inspections. However, it is arguable if the current “procedure-following” “level I-III” paradigm can withstand the changes that come along NDE 4.0. With the increased autonomy and interconnectedness expected with NDT 4.0, the majority of traditional NDE tasks will no longer be needed. Instead, different skills, such as that of programming and adapting systems, as well as problem solving, will become vital for the inspections. Therefore, we suggest that a new paradigm is needed—one in which inspector roles and, thus, also the requirements will have to be reinvented. We expect the inspectors to be relieved from the tedious and error prone aspects of the current system and to take responsibility for increasingly complex automated systems and work in closer collaboration with other experts. Thus, we propose that the traditional inspector roles will be transformed into that of the system developer, caretaker and problem solver, each requiring a specific set of skills and assuming different responsibilities. In this talk, we will present the new roles and discuss the challenges that may arise with them. T2 - NDE for industry – annual workshop CY - Online meeting DA - 29.06.2021 KW - Non-Destructive Evaluation KW - NDE 4.0 KW - Human-Machine Interaction KW - Industry 4.0 KW - Inspection Personnel KW - Human-Centered Approach KW - Human Factors KW - Acceptance PY - 2021 AN - OPUS4-53548 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija A1 - Virkkunen, I. T1 - NDE 4.0: Redefining Traditional Inspector Roles N2 - The successful shift to NDE 4.0 will not only require developing and embracing new technologies associated with the fourth industrial revolution or becoming an integral part of the overall Industry 4.0, but also developing and adopting new ways of working. It is undoubtful that people will remain in charge of the inspections. However, it is arguable if the current “procedure-following” “level I-III” paradigm can withstand the changes that come along NDE 4.0. With the increased autonomy and interconnectedness expected with NDT 4.0, the majority of traditional NDE tasks will no longer be needed. Instead, different skills, such as that of programming and adapting systems, as well as problem solving, will become vital for the inspections. Therefore, we suggest that a new paradigm is needed—one in which inspector roles and, thus, also the requirements will have to be reinvented. We expect the inspectors to be relieved from the tedious and error prone aspects of the current system and to take responsibility for increasingly complex automated systems and work in closer collaboration with other experts. Thus, we propose that the traditional inspector roles will be transformed into that of the system developer, caretaker and problem solver, each requiring a specific set of skills and assuming different responsibilities. In this talk, we will present the new roles and discuss the challenges that may arise with them. T2 - HOIS Digitalisation Forum (HDF) virtual seminar CY - Online meeting DA - 10.08.2021 KW - Non-Destructive Evaluation KW - NDE 4.0 KW - Human-Machine Interaction KW - Industry 4.0 KW - Inspection Personnel KW - Human-Centered Approach KW - Human Factors KW - Acceptance PY - 2021 AN - OPUS4-53549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija T1 - NDE 4.0: Redefining Traditional Inspector Roles N2 - The successful shift to NDE 4.0 will not only require developing and embracing new technologies associated with the fourth industrial revolution or becoming an integral part of the overall Industry 4.0, but also developing and adopting new ways of working. It is undoubtful that people will remain in charge of the inspections. However, it is arguable if the current “procedure-following” “level I-III” paradigm can withstand the changes that come along NDE 4.0. With the increased autonomy and interconnectedness expected with NDT 4.0, the majority of traditional NDE tasks will no longer be needed. Instead, different skills, such as that of programming and adapting systems, as well as problem solving, will become vital for the inspections. Therefore, we suggest that a new paradigm is needed—one in which inspector roles and, thus, also the requirements will have to be reinvented. We expect the inspectors to be relieved from the tedious and error prone aspects of the current system and to take responsibility for increasingly complex automated systems and work in closer collaboration with other experts. Thus, we propose that the traditional inspector roles will be transformed into that of the system developer, caretaker and problem solver, each requiring a specific set of skills and assuming different responsibilities. In this talk, we will present the new roles and discuss the challenges that may arise with them. T2 - International Virtual Conference on NDE 4.0, DGZfP CY - Online meeting DA - 14.04.2021 KW - Non-Destructive Evaluation KW - NDE 4.0 KW - Human-Machine Interaction KW - Industry 4.0 KW - Inspection Personnel KW - Human-Centered Approach KW - Human Factors KW - Acceptance PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-535524 UR - www.ndt.net/search/docs.php3?id=26328 AN - OPUS4-53552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija A1 - Lindt, Stanislav T1 - Human-machine interaction in the era of NDT 4.0 N2 - This presentation discusses industry 4.0 from the perspective of human machine interaction (HMI). Based on available literature the changes, new demands and possible problems related to people’s jobs as a result of increased digitisation and use of artificial intelligence are addressed. Combining literature with own experience in non-destructive testing (NDT), the author addresses the possible challenges and chances for the NDT personnel in the era of NDT 4.0. T2 - The BINDT Aerospace Event 2019 CY - National Composites Centre NCC, Bristol, UK DA - 09.04.2019 KW - ZfP 4.0 KW - Human Factors KW - NDT 4.0 PY - 2019 AN - OPUS4-48850 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija A1 - Ronneteg, U. T1 - Usability of the written procedures: an eye tracking study N2 - Usability of the written procedures: an eye tracking study Non-destructive evaluation (NDE) is regarded as one of the key elements in ensuring quality of engineering systems and their safe use. A failure of NDE to detect critical defects in safety-relevant components, such as those in the nuclear industry, may lead to catastrophic consequences for the environment and the people. NDE inspection procedure is one of the most important tools in the everyday life of an NDE inspector. Experience and research studies have shown that NDE procedures are not always used as foreseen and may need to be optimized. Both the content and format play an important role in producing reliable procedures. Whereas the content aids in the understanding of the task and in its subsequent correct execution, the format determines the efficiency and frequency of the procedure’s use. For the purposes of this study, an inspection procedure - designed to be used in the inspection of components used in the final disposal of spent nuclear fuel - was further developed by adopting a user-centered design. This was achieved by following the eye movements during a data evaluation task whilst using the procedure, by interviews and group discussions, accompanied by a review from a human factors’ perspective, the suggestions from relevant literature and by reiterating the entire process once again. This process resulted in identifying shortcomings and in suggesting alterations to the existing procedure. The newly created procedure was empirically tested for its usability using eye tracking. By comparing the old instruction format to the newly developed one, the results showed that appropriately highlighting warnings, exceptions, or reminders, and placing them at a logical position assures that they will be read and identified with ease rather than overlooked. The presentation of the information in a stepwise manner, with one action per step, allows the user to follow more easily the steps that must be carried out to save time and effort. This study - the first of its kind in the field of non-destructive evaluation - showed that the procedure can be improved by applying human factors principles to the design and by involving the users into the process of procedure development and quality assurance. Introduction of the speaker – Marija Bertovic Marija Bertovic has a degree in psychology and a PhD in human factors. Since 2006 she has been working on topics related to human factors in non-destructive testing at the BAM Federal Institute for Materials Research and Testing, German Society for Non-Destructive Testing and as an independent consultant. The focus of her research has been on identifying and studying human factors’ related risks during NDT inspections and suggesting ways of optimizing the inspections and inspection procedures. She is currently a research staff member at BAM responsible for probabilistic safety and reliability analyses AND human factors analyses. She is the chairwoman of the German Society for Non-Destructive Testing’s (DGZfP) subcommittee on human machine interaction and the winner of the DGZfP Science Award in 2018. T2 - AHFE International, 10th International Conference on Applied Human Factors and Ergonomics CY - Washington Hilton, Washington D.C., USA DA - 24.07.2019 KW - Human Factors KW - ZfP KW - NDE PY - 2019 AN - OPUS4-48851 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija A1 - Wall, M. T1 - Human-Factors in model-assisted POD approaches N2 - It is known that human factors (HF) affect the reliability of non-destructive testing (NDT). However, reliability is often expressed in probability of detection (POD) curves, obtained in practical trials, where human and organisational factors are considered only indirectly, through the few people taking part in the trials. Recently, we have observed an increase in the use of numerical modelling to obtain POD curves outside of practical trials. The so-called model-assisted POD(MAPOD) approaches have so far only very rarely included some kind of variation to account for HF. This talk presents different possibilities to include HF in MAPOD and discusses the advantages and disadvantages of each approach. T2 - The BINDT Aerospace Event 2019 CY - National Composites Centre NCC, Bristol, UK DA - 09.04.2019 KW - Human Factors KW - NDT KW - ZfP KW - MAPOD PY - 2019 AN - OPUS4-48852 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija T1 - Ironien der Automatisierung: Ein Blick von der menschlichen Seite N2 - In traditional NDT, human is seen as the main source of error. The advances in NDT 4.0 lead to believe that by increased automation, people, and therefore human error, can be diminished. The research on human-automation interaction shows that increased automation does not necessarily lead to a decrease of human error, a phenomenon dubbed as “automation ironies”, introduced by Bainbridge in 1987. The research shows that whereas with automation the known human error can be prevented, there is still room for new risks and error sources, which are unknown. As we advance from automation to industry 4.0 concepts, the possibility for human error shifts slightly to the developers of systems but remains in the interaction with systems as well, as the tasks and task demands change and give rise for possible failure at different stages of the NDT process, as once known. In der traditionellen zerstörungsfreien Prüfung wird der Mensch als Hauptfehlerquelle angesehen. Die Fortschritte bei der zerstörungsfreien Prüfung 4.0 lassen vermuten, dass durch eine verstärkte Automatisierung Menschen und damit menschliche Fehler verringert werden können. Die Untersuchung der Mensch-Automatisierungs-Interaktion zeigt, dass eine zunehmende Automatisierung nicht unbedingt zu einer Verringerung des menschlichen Fehlers führt, ein Phänomen, das 1987 von Bainbridge als „Automatisierungs-Ironien“ bezeichnet wurde. Die Untersuchungen zeigten, dass obwohl bei der Automatisierung bekannte menschliche Fehler verhindert werden können, gibt es noch Raum für neue Risiken und Fehlerquellen, die unbekannt sind. Während wir von der Automatisierung zu Industrie-4.0-Konzepten übergehen, verlagert sich die Möglichkeit menschlicher Fehler geringfügig auf die Entwickler von Systemen, bleibt jedoch auch in der Interaktion mit Systemen erhalten, da sich die Aufgaben und Aufgabenanforderungen ändern und es zu möglichen Fehlern in verschiedenen Phasen von ZfP-Prozessen kommen kann. T2 - Forum Produktionsmonitoring: Ausschussfrei produzieren CY - Frauenhofer EZRT, Fürth, Germany DA - 22.05.2019 KW - Human Factors KW - ZfP 4.0 PY - 2019 AN - OPUS4-48853 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija T1 - ZfP 4.0: Neue Herausforderungen für die Mensch-Maschine-Interaktion N2 - Im Zeitalter von Industrie 4.0 muss die zerstörungsfreie Prüfung (ZfP) mit den Anforderungen Schritt halten. Die erfolgreiche Umsetzung von Digitalisierung, Automatisierung, komplexer Vernetzung, künstlicher Intelligenz, Assistenzsystemen, intelligenten Sensortechnologien usw. hängt stark mit einer erfolgreichen und optimalen Mensch-Maschine-Interaktion (MMI) zusammen. In der ZfP 4.0 wird sich die Rolle des Prüfers zum flexiblen Problemlöser und Entscheider verändern. Dieser Wandel wird andere Anforderungen an die Prüfer stellen und eine andere Organisation der Prüfung, Ausbildung etc. erfordern. Der Mensch wird also weiterhin im Mittelpunkt der ZfP stehen. Zu den Herausforderungen, die dieser Wandel mit sich bringen wird, gehören das Vertrauen in automatisierte Systeme und die Akzeptanz neuer Technologien, für die Wege gefunden werden müssen, um sie zu bewältigen. T2 - DGZfP AK Zwickau-Chemnitz CY - Zwickau, Germany DA - 28.01.2020 KW - Mensch-Maschine-Interaktion KW - Zerstörungsfreie Prüfung (ZfP) KW - Industrie 4.0 KW - ZfP 4.0 PY - 2020 AN - OPUS4-51918 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija T1 - Reliability in NDT and the influence of human factors N2 - This presentation offers a holistic view on the assessment of reliability of NDT including the intrinsic reliability (typically expressed in terms of probability of detection (POD) curves), application, human and organisational factors. In addition to POD, advanced methods such as multiparameter POD, volume POD and POD for combined data are presented. Human and organisational factors in NDT require a systematic approach, i.e. it is not just the individual that determines how the inspections are carried out but also the interactions of individuals with the technology, team, organisation and the extra-organisational environment. Lessons learned from the literature as well as from own studies are presented. T2 - DFG SHM Netzwerk CY - Berlin, Germany DA - 27.01.2020 KW - Human Factors KW - Non-destructive testing (NDT) KW - Reliability PY - 2020 AN - OPUS4-51919 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija T1 - Psychology at BAM: Is it science and how can we benefit from it? N2 - The aim of this presentation is twofold: first, to present the field of psychology including its research methods and, second, to show on an example how psychology can be used in material research. The example is of the study of human factors in non-destructive testing (NDT), in which the author has more than 10 years of experience. The conclusion is that psychological methods can be used to identify human-related problems during different tasks and to generate mitigation strategies that can be used to decrease human error and enhance safety. T2 - Abteilungsseminar der Abteilung 8 CY - Berlin, Germany DA - 20.04.2020 KW - Psychology KW - Human factors KW - Non-destructive testing (NDT) KW - Safety PY - 2020 AN - OPUS4-51920 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija T1 - Human machine interaction in the era of industry 4.0 N2 - The fourth industrial revolution (also known as “Industry 4.0”) promises to relieve people from manual and physical work by developing cyber-physical systems and smart automation and thereby achieving a more efficient, reliable and safe performance. This will change people’s work from being operators of the system into becoming strategical decision makers and flexible problem solvers. This shift will require a new division of work between people and technical systems, a new division of responsibilities and new ways of interacting with technology, which in turn will pose new demands on people. People will require different physical and cognitive capabilities, different competencies and new strategies to cope with the upcoming challenges. The focus of Industry 4.0 is therefore on designing systems with human in the centre: systems that will extend people’s capabilities, that will allow collaborative work and take advantage of performances in which either people or technology excel. This presentation will focus on the benefits of consideration of human-machine interaction in the context of industry 4.0. T2 - Les assises de L’Industrie 4.0 CY - INSA Centre Val de Loire, Campus de Blois, France DA - 29.09.2020 KW - Human machine interaction KW - Industry 4.0 KW - NDT 4.0 KW - Safety KW - non-destructive testing (NDT) PY - 2020 AN - OPUS4-51921 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija T1 - Human-related risks in the nondestructivetesting (NDT) of hollow railway axles: implications for the education and training of the NDT personnel N2 - Non-destructive testing (NDT) is a major contributor to the safe railway operation. Even though NDT reliability in railway maintenance is affected by human factors, there are only just a few studies published in this field so far. Education and training of the NDT personnel are some of the most important drivers of safe and reliable NDT. Continuously improving current practices and tools used for educational purposes can be achieved not only through technical content, but also through the attention to human factors. The aim of this study was to deepen the understanding of possible human-related risks in the manual ultrasonic inspection of the hollow railway axles and to suggest measures to improve the education and training of the NDT personnel. This was achieved by means of Failure Modes and Effects Analysis (FMEA) carried out with eight NDT experts and by a survey of 27 experienced inspectors. The results show that failures can happen throughout the entire NDT process. Prevention of those failures could be improved through the optimization of the organization, technology, documentation and regulations, working conditions and the general process, and through the optimization of the formal education and training. Specialized training of the executives, extended training of the supervisors and the inspectors and improvement of the inspection documentation have been suggested. The study also showed potential for the improvements of the inspection in the field. T2 - 29th European Safety and Reliability Conference CY - Hannover, Germany DA - 22.09.2019 KW - Human Factors KW - Non-Destructive Testing KW - NDT KW - Education KW - Training KW - Failure Modes and Effects Analysis KW - Railway KW - Axle Inspection KW - Ultrasonic Testing KW - Reliability PY - 2019 AN - OPUS4-49729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija T1 - How can we use psychology to optimize the NDT inspection process and prevent human error N2 - The aim of this presentation is to highlight how psychology can be used to prevent human error. It starts with examples of accidents, incidents and events that have happened due to too little attention being dedicated to human factors. It continues arguing that human factors are one of the main factors influencing the reliability of non-destructive testing and gives definitions of the main terms. Furthermore, it presents a method used to identify risks in mechanized NDT to be used for the purposes of the final disposal of spent nuclear fuel and presents a study, in which human-centred design and eye tracking have been used to optimism the inspection procedure. The conclusion is that human factors methods can be used to identify problems during the inspection process and generate mitigation strategies that can be used to decrease human error and enhance safety. T2 - The Nordic Symposium on Nuclear Power CY - Stockholm, Sweden DA - 26.11.2018 KW - Zerstörungsfreie Prüfung KW - Human factors KW - Human error KW - Risk management PY - 2018 AN - OPUS4-46938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija A1 - Given, Joseph A1 - Lehleitner, Johannes T1 - First insights into the human-related risks of tunnel inspection N2 - Whereas human factors (HF) in the non-destructive testing (NDT) of metallic components are a poorly investigated topic (in comparison to other industrial fields such as aviation), HF in the inspection of concrete components are even less known. Studies have shown that there is always some variability between individuals in their inspection results and that HF affect the reliability of NDT inspections. The aim of the ongoing WIPANO project is to draft a standard for a holistic reliability assessment, with concrete inspection as one case study. This includes also the HF. A human-oriented Failure Modes and Effects Analysis (FMEA) was carried out to do the following: a) identify possible human-related risks in tunnel inspection processes using a laser scan method (including data collection,evaluation, and assessment of tunnel damage) and b) evaluate these human-related risks as regards their possible causes, consequences and probability of occurrence – in addition with respect to existing and possible preventive measures. The results show that the causes for possible failures can lie within people, the physical environment, technology, organisation, and extra-organisational environment. Whereas current preventive measures rely mostly on the individual and quality management practices, there is potential for even larger improvement at the organisational and extra-organisational level. The FMEA results were also used to develop a quantification method to further understand the HF in tunnel inspection, which could possibly be included in the information into the overall reliability assessment. The usage of qualitative and quantitative data collected through the human-FMEA within the proposed quantification method shows promise that HF can be quantified and could offer broader understanding of HF influences on inspection in various industries. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Human Factors KW - Failure Modes and Effects Analysis KW - FMEA KW - Tunnel Inspection KW - NDT Reliability KW - Quantification PY - 2022 AN - OPUS4-56015 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bintz, Thilo A1 - Munsch, Sarah A1 - Heyn, Rüdiger A1 - Hirsch, Hauke A1 - Grunewald, John A1 - Kruschwitz, Sabine T1 - Detailed investigation of capillary active insulation materials by 1H nuclear magnetic resonance (NMR) and thermogravimetric drying N2 - Capillary active interior insulation materials are an important approach to minimize energy losses of historical buildings. A key factor for their performance is a high liquid conductivity, which enables redistribution of liquid moisture within the material. We set up an experiment to investigate the development of moisture profiles within two different interior insulation materials, calcium-silicate (CaSi) and expanded perlite (EP), under constant boundary conditions. The moisture profiles were determined by two different methods: simple destructive sample slicing with subsequent thermogravimetric drying as well as non-destructive NMR measurements with high spatial resolution. The moisture profiles obtained from both methods show good agreement, when compared at the low spatial resolution of sample slicing, which demonstrates the reliability of this method. Moreover, the measured T2- relaxation-time distributions across the sample depth were measured, which may give further insight into the saturation degree of the different pore sizes. In order to explain differences in the moisture profiles between CaSi and EP, we determined their pore-size distribution with different methods: conversion of the NMR T2 relaxationtime distribution at full saturation, mercury intrusion porosimetry and indirect determination from pressure plate measurements. CaSi shows a unimodal distribution at small pore diameters, while in EP, a bi-modal or wider distribution was found. We assume that the smaller pore diameters of CaSi lead to a higher capillary conductivity, which causes a more distributed moisture profile in comparison with that of EP. T2 - NDT-CE CY - Zurich, Switzerland DA - 16.08.2022 KW - Insulation material KW - Nuclear magnetic resonance KW - Capillary conductivity KW - Pore-size distribution PY - 2022 AN - OPUS4-57918 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bintz, Thilo A1 - Kruschwitz, Sabine T1 - Investigation of Capillary Water Absorption of Clinker-Reduced Binders by NMR Relaxometry N2 - To evaluate the durability of new alternative cement compositions, it is important to examine the internal transport of moisture through these materials. For this purpose, mortars were prepared from different types of cement and capillary suction experiments were carried out. The moisture transport was studied with an NMR tomograph and compared with weight easurements. With the tomograph, the total moisture input could be determined, as well as the moisture content within the samples non-destructively and spatially resolved. This allows precise observation of the moisture fronts. The tomograph was also used to determine the capillary transport coefficient. T2 - ISEMA 2023 CY - Queensland, Australia DA - 25.09.2023 KW - NMR relaxometry KW - Capillary suction KW - Capillary transport coefficient PY - 2023 AN - OPUS4-59216 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bintz, Thilo A1 - Munsch, Sarah Mandy A1 - Stelzner, Ludwig A1 - Lauinger, R. A1 - Schmidt, Wolfram A1 - Kruschwitz, Sabine T1 - An NMR tomograph for building materials - applications , experimental studies and limitations N2 - Introduction of the NMR Tomograph of Department 8.0 at BAM, the applications, technical limitations, and uses in laboratory studies. T2 - International Conference on Electromagnetic Wave Interaction with Water and Moist Substances (ISEMA) 2021 CY - Kiel, Germany DA - 26.07.2021 KW - NMR relaxometry KW - NMR imaging KW - Sensitivity KW - Building materials PY - 2021 N1 - Geburtsname von Munsch, Sarah Mandy: Nagel, S. M. - Birth name of Munsch, Sarah Mandy: Nagel, S. M. AN - OPUS4-53043 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bircher, B. A1 - Meli, F. A1 - Küng, A. A1 - Bellon, Carsten A1 - Evsevleev, Sergei A1 - Katic, M. A1 - Heikkinen, V. A1 - Lassila, A. T1 - Compensation of machine geometry deviations for dXCT N2 - It is fundamental to determine the machine geometry accurately for dimensional X-ray computed tomography (XCT) measurements. When performing high-accuracy scans, compensation of a non-static geometry, e.g. due to rotary axis errors or drift, might become necessary. Here we provide an overview of methods to determine and account for such deviations on a per projection basis. They include characterisation of stage error motions, in situ geometry measurements, numerical simulations, and reconstruction-based optimization relying on image quality metrics and will be discussed in terms of their metrological performance. Since a radiographic calibration is always required to provide an initial absolute geometry, this method will be presented as well. T2 - dXCT conference 2021 CY - Online meeting DA - 17.05.2021 KW - Computed tomography PY - 2021 AN - OPUS4-54029 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Boehm, Rainer A1 - Heckel, Thomas A1 - Brackrock, Daniel A1 - Spruch, W. A1 - Beggerow, T. T1 - Kegel-Phased-Array für die schnelle Ultraschallprüfung von längsgebohrten Eisenbahnradsatzwellen N2 - Durch die Verwendung von Ultraschall - Phased Arrays lässt sich in vielen Fällen sowohl die Prüfgeschwindigkeit als auch die Zuverlässigkeit der Prüfung erhöhen. Für die Prüfung von Eisenbahnradsatzwellen ist die Phased Arraytechnik schon verbreitet, jedoch vor allem für die Prüfung von Vollwellen. Die Prüfung von längsgebohrten Eisenbahnrad¬satzwellen erfolgt typischerweise mit einer Anzahl von konventionellen Prüfköpfen, die rotierend durch die Längsbohrung bewegt werden. Dabei werden weder die Achsen und Räder noch die Bremsscheiben demontiert. Ein neuer Ansatz für die Prüftechnik ist die Verwendung eines rotations-symmetrischen kegelförmigen Phased Arrays in Tauchtechnik. Die Abtastung in Umfangs-richtung erfolgt durch elektronische Rotation des Schallfeldes, was viel höhere Prüfge-schwindigkeiten ermöglicht und den mechanischen Aufwand des Prüfsystems erheblich reduziert. Nur die Bewegung des Sensorsystems in axialer Richtung innerhalb der Bohrung erfolgt mechanisch. Senkrecht zur Bauteilachse kann das Schallbündel durch die Phased Arraysteuerung in Umfangsrichtung exakt ausgerichtet und im Abstand der Prüfbereiche nahe der Außenoberfläche der Radsatzwelle fokussiert werden. Die Konstruktionsparameter des Kegelarrays wurden speziell optimiert zum Auffinden von rissartigen Querfehlern in und in der Nähe der äußeren Oberfläche von längsgebohrten Eisenbahnradsatzwellen von Hochgeschwindigkeitszügen. Die Fehlerfläche liegt dabei in der Querschnittsfläche des Bauteils. Im Beitrag werden der Prototyp des neuen Sensorsystems und erste Prüfergebnisse gezeigt. Die Arbeiten wurden durchgeführt im Rahmen des Europäischen Projektes “Whole Life Rail Axle Assessment and Improvement Using Ultrasonic Phased array and Corrosion Inspection Systems“ (RAAI). T2 - 10. Fachtagung ZfP im Eisenbahnwesen, 13. – 15. März 2018 CY - Wittenberge, Germany DA - 13.03.2018 KW - Eisenbahn KW - Ultraschallprüfung KW - Radsatzwellen KW - Phased Array KW - Kegelarray KW - Rotationsscanner PY - 2018 AN - OPUS4-44523 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Boehm, Rainer T1 - Phased Array und Imaging, zwei raumzeitliche Interferenzverfahren N2 - Phased-Array-Technik und Bildgebung mit Ultraschallwellen sind nach langer Entwicklungszeit inzwischen auf dem Weg zu allgemeiner Verbreitung. Daher bietet sich an, die verschiedenen Techniken und deren Begriffe wie z.B. Phased-Array, SAFT, TFM, FMC und Sparse-Array zusammenfassend in Beziehung zu setzen. All diesen Techniken liegt dieselbe Idee zu Grunde, nämlich durch gezielte Überlagerung von Ultraschallsignalen den gewünschten Effekt zu erreichen. Die verschiedenen Techniken werden kurz charakterisiert und neben den Unterschieden wird beschreiben, auf welche Weise bei all diesen Techniken das Phänomen der konstruktiven Interferenz jeweils genutzt wird. T2 - Ultraschall-Array-Technologien und ihre Anwendungen, Seminar des FA Ultraschallprüfung der DGZfP CY - Berlin, Germany DA - 04.11.2019 KW - Phased Array KW - Imaging KW - Synthetic Aperture Focusing Technique KW - Total Focusing Methode KW - Full Matrix Capture PY - 2019 UR - https://www.dgzfp.de/seminar/ultraschall# AN - OPUS4-49791 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Breese, Philipp Peter A1 - Becker, Tina A1 - Oster, Simon A1 - Metz, C. A1 - Altenburg, Simon T1 - In-situ defect detection for laser powder bed fusion with active laser thermography N2 - Defects are still common in metal components built with Additive Manufacturing (AM). Process monitoring methods for laser powder bed fusion (PBF-LB/M) are used in industry, but relationships between monitoring data and defect formation are not fully understood yet. Additionally, defects and deformations may develop with a time delay to the laser energy input. Thus, currently, the component quality is only determinable after the finished process. Here, active laser thermography, a non-destructive testing method, is adapted to PBF-LB/M, using the defocused process laser as heat source. The testing can be performed layer by layer throughout the manufacturing process. The results of the defect detection using infrared cameras are presented for a custom research PBF-LB/M machine. Our work enables a shift from post-process testing of components towards in-situ testing during the AM process. The actual component quality is evaluated in the process chamber and defects can be detected between layers. T2 - 2023 Annual International Solid Freeform Fabrication Symposium CY - Austin, TX, USA DA - 14.08.2023 KW - Additive Manufacturing KW - Additive Fertigung KW - Laser Powder Bed Fusion KW - Nondestructive Testing KW - Flying Spot Laser Thermography PY - 2023 AN - OPUS4-58137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Breese, Philipp Peter A1 - Becker, Tina A1 - Oster, Simon A1 - Metz, C. A1 - Altenburg, Simon T1 - In-situ defect detection via active laser thermographic testing for PBF-LB/M N2 - Great complexity characterizes Additive Manufacturing (AM) of metallic components via laser powder bed fusion (PBF-LB/M). Due to this, defects in the printed components (like cracks and pores) are still common. Monitoring methods are commercially used, but the relationship between process data and defect formation is not well understood yet. Furthermore, defects and deformations might develop with a temporal delay to the laser energy input. The component’s actual quality is consequently only determinable after the finished process. To overcome this drawback, thermographic in-situ testing is introduced. The defocused process laser is utilized for nondestructive testing performed layer by layer throughout the build process. The results of the defect detection via infrared cameras are shown for a research PBF-LB/M machine. This creates the basis for a shift from in-situ monitoring towards in-situ testing during the AM process. Defects are detected immediately inside the process chamber, and the actual component quality is determined. T2 - Lasers in Manufacturing (LiM) CY - Munich, Germany DA - 26.06.2023 KW - Additive Manufacturing KW - Laser Powder Bed Fusion KW - Nondestructive Testing KW - Defect Detection KW - Flying Spot Laser Thermography PY - 2023 AN - OPUS4-57922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Breese, Philipp Peter A1 - Becker, Tina A1 - Oster, Simon A1 - Altenburg, Simon A1 - Metz, C. A1 - Maierhofer, Christiane T1 - Aktive Laserthermografie im L-PBF-Prozess zur in-situ Detektion von Defekten N2 - Die zerstörungsfreie Prüfung von metallischen Bauteilen hergestellt mit additiver Fertigung (Additive Manufacturing - AM) gewinnt zunehmend an industrieller Bedeutung. Grund dafür ist die Feststellung von Qualität, Reproduzierbarkeit und damit auch Sicherheit für Bauteile, die mittels AM gefertigt wurden. Jedoch wird noch immer ex-situ geprüft, wobei Defekte (z.B. Poren, Risse etc.) erst nach Prozessabschluss entdeckt werden. Übersteigen Anzahl und/oder Abmessung die vorgegebenen Grenzwerte für diese Defekte, so kommt es zu Ausschuss, was angesichts sehr langer Bauprozessdauern äußerst unrentabel ist. Eine Schwierigkeit ist dabei, dass manche Defekte sich erst zeitverzögert zum eigentlichen Materialauftrag bilden, z.B. durch thermische Spannungen oder Schmelzbadaktivitäten. Dementsprechend sind reine Monitoringansätze zur Detektion ggf. nicht ausreichend. Daher wird in dieser Arbeit ein Verfahren zur aktiven Thermografie an dem AM-Prozess Laser Powder Bed Fusion (L-PBF) untersucht. Das Bauteil wird mit Hilfe des defokussierten Prozesslasers bei geringer Laserleistung zwischen den einzelnen gefertigten Lagen unabhängig vom eigentlichen Bauprozess erwärmt. Die entstehende Wärmesignatur wird ort- und zeitaufgelöst durch eine Infrarotkamera erfasst. Durch diese der Lagenfertigung nachgelagerte Prüfung werden auch zum Bauprozess zeitversetzte Defektbildungen nachweisbar. In dieser Arbeit finden die Untersuchungen als Proof-of-Concept, losgelöst vom AM-Prozess, an einem typischen metallischen Testkörper statt. Dieser besitzt eine Nut als oberflächlichen Defekt. Die durchgeführten Messungen finden an einer eigens entwickelten L-PBF-Forschungsanlage innerhalb der Prozesskammer statt. Damit wird ein neuartiger Ansatz zur aktiven Thermografie für L-PBF erforscht, der eine größere Bandbreite an Defektarten auffindbar macht. Der Ansatz wird validiert und Genauigkeit sowie Auflösungsvermögen geprüft. Eine Anwendung am AM-Prozess wird damit direkt forciert und die dafür benötigten Zusammenhänge werden präsentiert. T2 - DGZfP-Jahrestagung 2022 CY - Kassel, Germany DA - 23.05.2022 KW - Additive Manufacturing KW - Laser Powder Bed Fusion KW - Thermografie KW - Zerstörungsfreie Prüfung KW - Aktive Laserthermografie PY - 2022 AN - OPUS4-55040 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Breese, Philipp Peter A1 - Becker, Tina A1 - Oster, Simon A1 - Metz, C. A1 - Altenburg, Simon T1 - In-situ Prüfung additiv gefertigter L-PBF-Bauteile mit aktiver Laserthermografie N2 - Die additive Fertigung von metallischen Bauteilen (Additive Manufacturing - AM; auch 3D-Druck genannt) bietet eine Vielzahl an Vorteilen gegenüber konventionellen Fertigungsmethoden. Durch den schichtweisen Auftrag und das selektive Aufschmelzen von Metallpulver im Laser Powder Bed Fusion Prozess (L-PBF) sind u.a. optimierte und flexibel anpassbare Designs und die Nutzung von neuartigen Materialien möglich. Aufgrund der Komplexität des AM-Prozesses und der Menge an Einflussfaktoren ist eine Qualitätssicherung der gefertigten Bauteile unabdingbar. Verschiedene in-situ Monitoringansätze werden bereits angewendet, jedoch findet eine dedizierte Prüfung erst im Nachgang der Fertigung ex-situ statt. Der Grund dafür ist, dass die Entstehung von geometrischen Abweichungen und Defekten auch zeitversetzt zum eigentlichen Materialauftrag und damit auch zum Monitoring stattfinden kann. Die Notwendigkeit geeigneter in-situ Prüfmethoden für L-PBF, um die Erforderlichkeit einer Nacharbeitung frühzeitig festzustellen und Ausschuss zu vermeiden ist angesichts kostenintensiver Ausgangsstoffe und einer oftmals mehrstündigen bis mehrtägigen Prozessdauer besonders hoch. Daraus motiviert wird im Rahmen des Projektes ATLAMP die Möglichkeit der aktiven Laserthermografie mit Hilfe des defokussierten Fertigungslasers untersucht. Damit ist, bei vergleichsweise geringer Laserleistung, eine zerstörungsfreie Prüfung mittels Flying Spot Thermografie möglich. Diese findet jeweils anschließend an die Fertigung einer Schicht statt, womit der reale Status des Bauteils im Verlauf des AM-Prozesses geprüft wird. Als Grundlage dafür werden im Rahmen dieser Arbeit mit AM gefertigte, defektbehaftete Probekörper zunächst losgelöst vom Fertigungsprozess untersucht. Damit werden die Grundlagen für den neuartigen Ansatz der aktiven in-situ Laserthermografie im L-PBF-Prozess mittels des Fertigungslasers geschaffen. Auf diese Weise lassen sich auch zeitversetzt auftretende Defekte zerstörungsfrei im Prozessverlauf feststellen und eine aussagekräftige Qualitätssicherung des Ist-Zustands des Bauteils erreichen. T2 - Thermographie-Kolloquium 2022 CY - Saarbrücken, Germany DA - 28.09.2022 KW - Additive Manufacturing KW - Laser Powder Bed Fusion KW - Defekte KW - Zerstörungsfreie Prüfung KW - Aktive Laserthermografie PY - 2022 UR - https://www.dgzfp.de/Portals/thermo2022/BB178/Inhalt/18.pdf SN - 978-3-947971-27-5 AN - OPUS4-56810 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brence, Blaž A1 - Lugovtsova, Yevgeniya A1 - Prager, Jens T1 - Interdigital Transducers for Structural Health Monitoring N2 - Interdigital transducers (IDTs) are a well-known tool for excitation of surface acoustic waves. The use of IDTs is versatile, but they are most commonly employed as actuators for excitation of ultrasonic guided waves (UGWs). However, they are still a relatively new technology, which leaves many possibilities for future research, especially in the scope of newly emerging structural health monitoring (SHM) systems. IDTs offer low weight, design flexibility and beam directivity, which make them ideal candidates for employment in such systems. Due to the IDTs’ and waves’ complexity, problems often cannot be described analytically, therefore they require numerical solutions and experimental validations. In this contribution, a novel, simple use of IDTs, in the scope of SHM is described. Firstly, numerical findings acquired with finite element method are presented. To validate those results, experiments in a plate-like waveguide are carried out. A good agreement between them is found. The results show the potential of the IDTs in yet another prospective application, which could be attractive for adoption in the future. T2 - DAGA 2022 - Jahrestagung für Akustik CY - Stuttgart, Germany DA - 21.03.2022 KW - Lamb waves KW - Ultrasonic Guided Waves KW - Selective excitation PY - 2022 AN - OPUS4-55500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brence, Blaž A1 - Bulling, Jannis A1 - Lugovtsova, Yevgeniya A1 - Kraemer, P. A1 - Prager, Jens T1 - Determination of a notch depth using ultrasonic guided waves N2 - In non-destructive testing and structural health monitoring, ultrasonic guided waves (UGWs) are of great interest for finding and characterizing structural flaws. The interaction of the waves with the flaws can often not be described analytically due to waves’ complexity. This makes numerical simulations and experiments indispensable. However, mentioned field of research is still relatively young and most of the methods focus on flaw localization, using time of flight of the reflected signal. This leaves many possibilities for further research, especially when it comes to separate analysis of different propagating modes. It is well-known that ultrasonic wave modes convert when interacting with flaws. When a fundamental mode (A0 or S0) encounters a notch, it interacts and converts to another fundamental mode. In this contribution, this effect is used to analyze the depth of a notch. Firstly, numerical simulations are presented, which show notch depth proportionality to amplitude ratio of fundamental modes. To validate these results, experiments were carried out on a metal plate with a shallow notch which was gradually deepened. UGWs were excited using a polymer-based interdigital transducer (IDT) and detected with a 3D laser Doppler vibrometer. The IDT is employed to ensure excitation of a single mode and thus to reduce the complexity of the analysis. Good agreement between numerical and experimental results has been found. The results show the potential of UGWs not only for defect reconstruction and localization, but also its precise sizing. T2 - 10th European Workshop on Structural Health Monitoring (EWSHM 2022) CY - Palermo, Italy DA - 04.07.2022 KW - Lamb waves KW - Numerical simulation KW - Selective excitation PY - 2022 AN - OPUS4-55502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni A1 - Evsevleev, Sergei A1 - Sevostianov, I. A1 - Mishurova, Tatiana A1 - Hofmann, M. A1 - Koos, R. A1 - Requena, G. A1 - Garces, G. T1 - Explaining Deviatoric Residual Stresses and Load Transfer in Aluminum Alloys and Composites with Complex Microstructure N2 - The residual stresses and load transfer in multiphase metal alloys and their composites (with both random planar-oriented short fibers and particles) will be shown, as studied by neutron diffraction, by X-ray computed tomography, and by a model based on the reformulation of classic Maxwell’s homogenization method. Contrary to common understanding and state-of-the-art models, we experimentally observe that randomly oriented phases possess non-hydrostatic residual stress. Moreover, we disclose that the unreinforced matrix alloy stays under hydrostatic compression even under external uniaxial compression. The recently developed modeling approach allows calculating the residual stress in all phases of the composites. It rationalizes the presence of deviatoric stresses accounting for the interaction of random oriented phases with fibers having preferential orientation. It also allows the explanation of the unconventional in-situ behavior of the unreinforced alloy and the prediction of the micromechanical behavior of other similar alloys. T2 - MLZ Konferenz 2022 CY - Lenggries, Germany DA - 31.05.2022 KW - Residual Stresses KW - Aluminium Alloys KW - Microstructures PY - 2022 AN - OPUS4-55020 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni A1 - Evsevleev, Sergei A1 - Mishurova, Tatiana A1 - Meinel, Dietmar A1 - Koptyug, A. A1 - Surmeneva, M. A1 - Khrapov, D. A1 - Paveleva, A. A1 - Surmenev, R. T1 - Röntgen-Computertomographie-Verfahren zur quantitativen Charakterisierung periodischer Minimalflächenstrukturen (TMPS) N2 - Additiv gefertigte (AM) dreifach periodische metallische minimale Oberflächenstrukturen (TPMSS, aus dem Englischen Triply Periodic Minimum Surface Structures) erfüllen mehrere Anforderungen sowohl im biomedizinischen als auch im technischen Bereich: Abstimmbare mechanische Eigenschaften, geringe Empfindlichkeit gegenüber Herstellungsfehlern, mechanische Stabilität und hohe Energieabsorption. Allerdings stellen sie auch einige Herausforderungen in Bezug auf die Qualitätskontrolle dar, die ihre erfolgreiche Anwendung verhindern können. Tatsächlich ist die Optimierung des AM-Prozesses ohne die Berücksichtigung struktureller Merkmale wie Fertigungsgenauigkeit, interne Defekte sowie Oberflächentopographie und -rauheit unmöglich. In dieser Studie wurde die quantitative zerstörungsfreie Analyse von Ti-6Al-4V-Legierung TPMSS mit Hilfe der Röntgen-Computertomographie (XCT) durchgeführt. Es werden mehrere neue Bildanalyse-Workflows vorgestellt, um die Auswirkungen der Aufbaurichtung auf die Wanddickenverteilung, die Wanddegradation und die Verringerung der Oberflächenrauheit aufgrund des chemischen Ätzens von TPMSS zu bewerten. Es wird gezeigt, dass die Herstellungsgenauigkeit für die Strukturelemente, die parallel und orthogonal zu den hergestellten Schichten gedruckt werden, unterschiedlich ist. Verschiedene Strategien für das chemische Ätzen zeigten unterschiedliche Pulverabtragsfähigkeiten und damit ein Gradient der Wanddicke. Dies wirkte sich auf die mechanische Leistung unter Druck durch die Verringerung der Streckspannung aus. Eine positive Auswirkung des chemischen Ätzens ist die Verringerung der Oberflächenrauhigkeit, die möglicherweise die Ermüdungseigenschaften der Bauteile verbessern kann. Schließlich wurde XCT eingesetzt, um die Menge des zurückgehaltenen Pulvers mit der Porengröße des TPMSS zu korrelieren, wodurch der Herstellungsprozess weiter verbessert werden kann. T2 - DGZfP-Jahrestagung 2022 CY - Kassel, Germany DA - 23.05.2022 KW - Additive Fertigung KW - Computertomographie KW - Wändedicke KW - Machine Learning PY - 2022 AN - OPUS4-55021 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni A1 - Evsevleev, Sergei A1 - Mishurova, Tatiana A1 - Meinel, Dietmar A1 - Koptyug, A. A1 - Surmeneva, M. A1 - Khrapov, D. A1 - Paveleva, A. A1 - Surmenev, R. T1 - Procedures for quantitative characterization of periodic minimal surface structures (TMPSS) N2 - Additively manufactured (AM) triply periodic metallic minimum surface structures (TPMSS, from the English Triply Periodic Minimum Surface Structures) fulfill several requirements in both biomedical and engineering fields: tunable mechanical properties, low sensitivity to manufacturing defects, mechanical stability, and high energy absorption. However, they also present some quality control challenges that may prevent their successful application. In fact, optimization of the AM process is impossible without considering structural features such as manufacturing accuracy, internal defects, and surface topography and roughness. In this study, quantitative nondestructive analysis of Ti-6Al-4V alloy TPMSS was performed using X-ray computed tomography (XCT). Several new image analysis workflows are presented to evaluate the effects of buildup direction on wall thickness distribution, wall degradation, and surface roughness reduction due to chemical etching of TPMSS. It is shown that the fabrication accuracy is different for the structural elements printed parallel and orthogonal to the fabricated layers. Different strategies for chemical etching showed different powder removal capabilities and thus a gradient in wall thickness. This affected the mechanical performance under compression by reducing the yield stress. A positive effect of chemical etching is the reduction of surface roughness, which can potentially improve the fatigue properties of the components. Finally, XCT was used to correlate the amount of powder retained with the pore size of the TPMSS, which can further improve the manufacturing process. T2 - MSE 2022 CY - Darmstadt, Germany DA - 27.09.2022 KW - Surface roughness KW - Additive manufacturing KW - Computed tomography KW - Wall thickness KW - Machine learning KW - Manufacturing defects PY - 2022 AN - OPUS4-56162 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni A1 - Serrano Munoz, Itziar A1 - Fernandez, R. A1 - Gonzalez-Doncel, G. A1 - Garces, G. T1 - A paradigm shift in the description of creep in metals can only occur through multi-scale imaging N2 - The description of creep in metals has reached a high level of complexity; fine details are revealed by all sorts of characterization techniques and different theoretical models. However, to date virtually no fully microstructure-driven quantitative description of the phenomenon is available. This has brought to interesting inconsistencies; the classic description of (secondary) creep rests on the so-called power law, which however: a- has a pre-factor spanning over 10 orders of magnitude; b- has different reported exponents for the same material; c- has no explanation for the values of such exponents. Recently, a novel description (the so-called Solid State Transformation Creep (SSTC) Model) has been proposed to tackle the problem under a different light. The model has two remarkable features: 1- it describes creep as the accumulation of elementary strains due to dislocation motion; 2- it predicates that creep is proceeding by the evolution of a fractal arrangement of dislocations. Such description, however, needs a great deal of corroborating evidence, and indeed, is still incomplete. To date, we have been able to observe and somehow quantify the fractal arrangement of microstructures through Transmission Electron Microscopy (TEM), observe the accumulation of dislocations at grain boundaries by EBSD-KAM (Electron Back-Scattered Diffraction-Kernel Angular Misorientation) analysis, quantify the kinetic character (solid state transformation) of experimental creep curves, and estimate the sub-grain size of the fractal microstructure through X-ray refraction techniques. All pieces of the mosaic seem to yield a consistent picture: we seem being on the right path to reconstruct the whole elephant by probing single parts of it. What is still missing is the bond between the various scales of investigation. T2 - Korrelative Materialcharakterisierung 2022 CY - Dresden, Germany DA - 13.10.2022 KW - X-ray refraction KW - EBSD KW - Alloys KW - TEM KW - SEM PY - 2022 AN - OPUS4-56163 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni A1 - Serrano Munoz, Itziar A1 - Roveda, Ilaria A1 - Kupsch, Andreas A1 - Müller, Bernd R. T1 - Synchrotron X-Ray Refraction during in-situ heat treatments N2 - In this work, synchrotron X-ray refraction radiography (SXRR) was combined with in-situ heat treatment to monitor microstructure and porosity evolution as a function of temperature. The investigated material was a laser powder bed fusion (LPBF) manufactured AlSi10Mg, where the initial eutectic Si network is known to break down into larger particles with increasing temperature. Such alloy is also prone to thermally induced porosity (TIP). We show that SXRR allows detecting the changes in the Si-phase morphology upon heating, while this is currently possible only using scanning electron microscopy. SXRR also allows observing the growth of pores, usually studied via X-ray computed tomography, but on much smaller fields-of-view. Our results show the great potential of in-situ SXRR as a tool to gain in-depth knowledge of the susceptibility of any material to thermally induced damage and/or microstructure evolution over statistically relevant volumes. T2 - MSE 2022 CY - Darmstadt, Germany DA - 27.09.2022 KW - Si network KW - Al alloys KW - PBF-LB KW - X-ray refraction radiography KW - Pore nucleation PY - 2022 AN - OPUS4-56161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni A1 - Mishurova, Tatiana A1 - Serrano Munoz, Itziar A1 - Roveda, Ilaria A1 - Fritsch, Tobias A1 - Evans, Alexander A1 - Ulbricht, Alexander A1 - Schröder, Jakob A1 - Sprengel, Maximilian T1 - Redefining residual stress analysis to tackle the challenges posed by additively manufactured materials and structures N2 - Additively manufactured (and in particular laser powder bed fused) materials represent a manyfold challenge for the materials scientist and engineer because of their distinctive microstructure. If laser powder bed fusion is used to produce components, the complexity level increases because meso-structures (e.g., overhanging features, surface and internal defects) gain importance. Furthermore, if the main advantage of additive manufacturing, i.e., the freedom of design, is to be fully exploited, and geometrically complex structures, such as lattices, are manufactured, then such structures become meta-materials. This means that the geometry and the materials properties become equally important. This matryoshka-like (more literary than the dry “multi-scale”) complexity makes the characterization of the residual stress fields by means of diffraction methods so difficult with the current means, that new paradigms are necessary to tackle the challenge. Indeed, classic open problems acquire an extra layer of difficulty, such that new solutions need to be found and the sometimes-dormant debate needs to be re-opened. Examples include the determination of: a- the unstrained reference: this reference can become location-dependent and needs to be carefully determined; b- the so-called diffraction elastic constants, which becomes immensely challenging since even the single-crystal elastic constants are not known for additively manufactured materials. On top of this, other problems arise. The determination of the principal axes of stress becomes non-trivial because the hatching strategy sometimes dominates over the sample geometry. Even further, in complex structures, such as lattices, the textbook statement that the strain measurement in six independent directions uniquely identifies the strain tensor becomes simply invalid. The peculiar surface features of additively manufactured materials transform trivial tasks into formidable challenges: the precise alignment of a specimen in a beam or the determination of surface stresses with laboratory X-rays need to be thoroughly re-discussed and lay far from being routine tasks. In this paper, we will show a few examples of the cases mentioned above. We will demonstrate that sometimes the classic approach works very well, but other times surprising conclusions can be drawn from in-depth studies of the residual stress in additively manufactured materials. In short, we predicate that classic methods cannot be used on additively manufactured materials and structures without a critical evaluation of their validity and application range. T2 - ICRS11 CY - Nancy, France DA - 28.03.2022 KW - Neutron diffraction KW - Laser powder bed fusion KW - Diffraction elastic constants KW - Unstrained reference KW - Surface roughness KW - Porosity PY - 2022 AN - OPUS4-54642 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni A1 - Laquai, René A1 - Wieder, Frank A1 - Kupsch, Andreas A1 - Müller, Bernd R. A1 - Serrano Munoz, Itziar T1 - The combined use of X-ray refraction and trans-mission radiography and computed tomography N2 - Alternative to conventional transmission-based radiography and computed tomography, X-ray refraction techniques are being increasingly used to detect damage in light materials. In fact, their range of application has been recently extended even to metals. The big advantage of X-ray refraction techniques is that they are able to detect nanometric defects, whose size would lie below the resolution of even state-of-the-art synchrotron-based X-ray computed tomography (SXCT). The superiority of synchrotron X-ray refraction radiography and tomography (SXRR and SXRCT) has been shown in the case of light materials, in particular composites. X-ray refraction techniques also yield a quantitifaction of the amount of damage (the so-called relative internal specific surface) and can well be compared with damage models. At the same time, it is impossible for SXRR and SXRCT to image single defects. We show that the combination of refraction- and transmission-based imaging techniques yields an impressive amount of additional information about the type and amount of defects in microstructured materials such as additively manufactured metals or metal matrix composites. We also show that the use of data fusion techniques allows the classification of defects in statistically significant representative volume elements. T2 - 11th Conference on Industrial Computed Tomography CY - Online meeting DA - 08.02.2022 KW - X-ray refraction radiography KW - Computed Tomography KW - Synchrotron radiation KW - Additive manufacturing KW - Damage evolution PY - 2022 AN - OPUS4-54327 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni A1 - Müller, Bernd R. A1 - Kupsch, Andreas T1 - Röntgen Bildgebende Absorptions- und Refraktionsverfahren zur Charakterisierung keramischer Werkstoffe N2 - Wir präsentieren Labor- und Synchrotron-Röntgenrefraktionstechniken, wie sie an der BAM implementiert sind. Wir zeigen, dass die Labor-Röntgenrefraktionstopographie (XRRT) und die Synchrotron-Röntgenrefraktionsradiographie (SRRR) außergewöhnliche Werkzeuge zur Untersuchung von Schädigungen und inneren Defekten (Poren, Mikrorisse) in leichten Materialien wie Keramiken und Kompositen sind. Tatsächlich nutzen diese Techniken den an Grenzflächen auftretenden Röntgenbrechungseffekt aus, um den Kontrast zwischen dem (schwach absorbierenden) Objekt und dem Hintergrund zu erhöhen. Dies ermöglicht die Erkennung sehr kleiner Objekte (sogar bis zu 1 nm Rissöffnung) und die Quantifizierung ihrer spezifischen Oberfläche, die mit ihrem Einfluss auf die Materialeigenschaften korreliert. Wir zeigen die folgenden Anwendungen: a) Quantifizierung der Faserentbindung in laminaten Epoxid-Kohlenstoff-Verbundwerkstoffen; b) Mapping der Porengröße in gesinterten Keramiken; c) Eindringstiefe von Aschen in Keramikschutzschichten; d) Quantifizierung der Porenorientierung in Diesel Partikelfiltern; e) 3D-Darstellung von Makrorissen und Faserentbindung in Verbundwerkstoffen auf Ti-Basis für Anwendungen in der Luft- und Raumfahrt (unter Verwendung von Röntgenrefraktionstomographie). T2 - IAK Keramikbearbeitung CY - Online meeting DA - 22.10.2021 KW - Röntgenrefraktion KW - Leichtbau KW - Keramiken KW - Poren KW - Risse PY - 2021 AN - OPUS4-54069 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni A1 - Meinel, Dietmar A1 - Oesch, Tyler T1 - Analysis of damage processes in concrete - What can CT do? N2 - In this talk the basics of X-ray computed tomography (XCT) are presented, together with a description of complementary techniques such as Laminography and Stereoradiography. A overview of the common reconstruction approach and of the artifacts that can occur during reconstruction or acquisition of XCT images is also given. Finally, application examples in the field of construction materials are given, whereby several experimental techniques (Region of Interest Approach) and data analysis methods (e.g. Digital volume correlation) are explained. Such techniques and algorithms are used to extract quantitative information from ex- and in-situ experiments. T2 - Seminar DFG GRK 2250/1 Summer School CY - Online meeting DA - 21.06.2021 KW - Asphalt, porosity KW - Concrete KW - 3D rendering KW - Crack segmentation KW - Water uptake PY - 2021 AN - OPUS4-52837 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - Mechanical and thermal properties of aluminum titanate (AT) N2 - In this seminar I present the microstructure and micromechanical properties of diesel particulate filter materials, and then particularize them to porous microcracked aluminum titanate. I show that neutron diffraction is particularly suited for bulk studies, especially under applied load or at high temperatures. The combination of macroscopic and microscopic tests with modeling and simulation yields great added value to understand the mechanics of microcracking. T2 - Webinar DFG Hotmix CY - Online meeting DA - 14.06.2021 KW - Imaging KW - Neutron and X-ray Diffraction KW - Non-linear stress-strain KW - Anisotropy KW - Microcracking KW - Porosity PY - 2021 AN - OPUS4-52838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - Assessing the safety of new technologies: Summary of Project AGIL N2 - In Additive Manufacturing everybody is talking about Free Form, Unconventional Design, Re-thinking Components, “Think out of the box”. However, there are a few outstanding question: a) What are the material properties ? They certainly differ from literature values for conventional materials; b) How about the microstructure? It is different from conventional materials. Does it stay so with ageing? How does it form? c) Do we properly take residual stress into account? We often blame them for our ignorance about failure scenarios. d) Do we apply tailored heat treatments? Very often, we follow conventional schedules… This talk describes the summary of the efforts carried out within the BAM Project AGIL. At BAM, we aimed to thoroughly investigate the microstructure and how it evolves as a function of load and temperature (service), to determine the material properties after different process and service conditions, to properly determine residual stress and the way it impacts mechanical properties and component performance, to properly quantify the impact of (unavoidable?) defects, and to determine heat treatments tailored to the process-specific material (stress relieve, microstructure homogenization etc.). The Project AGIL was and is intimately coupled with the project ProMoAM, dealing with online monitoring of AM processes. T2 - Workshop In-situ Monitoring and Microstructure Development in Additive Manufactured Alloys CY - Online meeting DA - 19.04.2021 KW - Mechanical properties KW - Additive manufacturing KW - Residual Stress KW - Microstructure KW - Fatigue KW - Creep PY - 2021 AN - OPUS4-52581 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -