TY - CONF A1 - Strangfeld, Christoph T1 - Moisture testing and mapping N2 - Most building materials are porous and hydrophilic. Thus, for condition assessment and damage detection a determination of the material moisture is required. In this lecture, a short overview is given regarding moisture transport in porous media in the hygroscopic range. Then, several non-destructive measurement techniques are introduced. Here, the focus lies on their practical application and limitations. T2 - NDT&E Advanced Training Workshop CY - Berlin, Germany DA - 03.07.2024 KW - Building materials KW - Concrete KW - Material moisture KW - Moisture measurement techniques KW - Moisture transport PY - 2024 AN - OPUS4-60605 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lengas, Nikolaos A1 - Müller, Karsten A1 - Schlick-Hasper, Eva A1 - Neitsch, Marcel A1 - Johann, Sergej A1 - Zehn, Manfred W. T1 - Drop test simulation of packaging for dangerous goods: Investigation of appropriate drop height adjustment N2 - In the approval process of dangerous goods packagings, drop tests onto a flat, essentially unyielding surface are used to assess resistance against mechanical damage. International adopted regulations like ADR and RID define filling good dependent drop heights and filling degrees whilst the user needs to define the maximum gross mass to be tested and approved. Maximum packaging gross mass is defined conservatively and not reached in practice. To meet the defined gross mass in testing, using additives is permitted. However, in some cases, additives are not desirable due to packaging design or filling substance properties. This leads to deviations from the initial gross mass definition. Hence, a certain drop height adjustment is necessary to achieve the required impact loading. Laboratories frequently adjust drop height assuming a perfectly elastic collision which is inaccurate. Appropriate adjustment is not trivial due to energy conversion processes, e.g., plastic deformation. In this work, a test stand is developed for measuring the change in kinetic energy of different packaging designs and filling substances in regulative drop tests. The experimental results are used to validate finite-element (FE) models so that packaging properties can be varied in simulated drop test scenarios. The findings intend to describe the appropriate drop height adjustment of the respective packaging with same design but deviating gross mass to produce comparable mechanical response. The results are highly beneficial for testing laboratories, approval issuing authorities and packaging institutes confronted with the problem of testing packages with gross masses other than those to be approved. T2 - 24th IAPRI World Conference CY - Valencia, Spain DA - 17.06.2024 KW - Dangerous goods packagings KW - FEM KW - Drop test KW - Mechanical response PY - 2024 AN - OPUS4-60607 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krankenhagen, Rainer A1 - Chaudhuri, Somsubrho A1 - Pittner, Andreas A1 - Winterkorn, Rene A1 - Palumbo, Davide A1 - de Finis, Rosa A1 - Galietti, Umberto T1 - Thermographic Investigation of the Anisotropic Behaviour of Additively Manufactured AISI 316 Steel using DED-arc N2 - Additive manufacturing is one of the most promising techniques for industrial production and maintenance, but the specifics of the layered structure must be considered. The Direct Energy Deposition-Arc process enables relatively high deposition rates, which is favourable for larger components. For this study, specimens with different orientations were prepared from one AISI316 steel block – parallel and orthogonal to the deposition plane. Quasistatic tensile loading tests were carried out, monitored by an infrared camera. The obtained surface temperature maps revealed structural differences between both orientations. The consideration of surface temperature transients yields more details about the behaviour of the material under tensile loading than the conventional stress-strain-curve. These preliminary investigations were supplemented by thermographic fatigue trials. Although the anisotropy was also observed during fatigue loading the fatigue behaviour in general was the same, at least for both inspected specimens. The presented results demonstrate the abilities and the potential of thermographic techniques for tensile tests. T2 - 17th Quantitative Infrared Thermography Conference CY - Zagreb, Croatia DA - 01.07.2024 KW - Thermoelastic effect KW - Thermoplastic effect KW - Thermal stress analysis PY - 2024 AN - OPUS4-60574 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hassenstein, Christian A1 - Heckel, Thomas A1 - Hirsch, Philipp Daniel A1 - Vöhringer, Daniel A1 - Prager, Jens T1 - Automatisierte Wanddickenbestimmung an Prüfteilen mit komplexen Geometrien aus anisotropen Werkstoffen N2 - Im Rahmen des Projektes MRO2.0, das sich mit der digitalen Transformation des Servicezyklus von modernen Gasturbinenschaufeln beschäftigt, wurde gezeigt, wie sich automatisiert und flächendeckend die (Rest-)Wanddicke an variabel gekrümmten Prüfgeometrien bestimmen lässt. Es wurde ein Roboterarm verwendet, der ein lineares Ultraschallarray in Tauchtechnik führt und Prüfdaten aufnimmt, die mit einer adaptierten TFM (Total Focusing Method) zu Rekonstruktionen der Außen- und Innenoberfläche verarbeitet werden. In der aktuellen zweiten Projektphase wird die Methode für Werkstoffe erweitert, die anisotrope akustische Eigenschaften aufweisen. In diesem Beitrag wird eine Methode vorgestellt, wie sich die Kristallausrichtung bzw. die richtungsabhängige Schallgeschwindigkeit mittels eines linearen Ultraschallarrays bestimmen lässt. Für den Sendefall eines Randelements in Kontakttechnik können dabei Wellen identifiziert werden, die sich parallel zur Prüfkopfapertur im Prüfobjekt ausbreiten und mit der richtungsabhängigen Schallgeschwindigkeit skalieren. Die ermittelte Schallgeschwindigkeitsverteilung kann dann verwendet werden, um die lokale Wanddickenbestimmung für die Anisotropie zu adaptieren. T2 - 6. Workshop Messtechnische Anwendungen von Ultraschall CY - Drübeck, Germany DA - 17.06.2024 KW - Ultraschallprüfung KW - Anisotropie KW - Turbinenschaufel KW - NDT 4.0 PY - 2024 AN - OPUS4-60568 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hassenstein, Christian A1 - Wassermann, Jonas A1 - Hirsch, Philipp Daniel A1 - Heckel, Thomas T1 - Automated self-adjustment of array probe with a robotic ultrasonic test system N2 - Ultrasonic testing (UT) of objects with complex geometries often requires the use of a robotic arm to position the probe perpendicular to the local surface. Using immersion makes it possible to test these objects with standard ultrasonic linear array probes. Here, the probe positions and orientations provided by the robot are used for merging the locally acquired image data into a 3D-reconstruction. The quality of this reconstruction is highly dependent on the alignment of the tool center point (TCP) of the physical probe with the TCP used in the digital model. For common industrial tools, the TCP is usually acquired using geometric features of the tools. However, for ultrasonic arrays in immersion, there is a water standoff between the probe and the test object, therefore the TCP is in free space in front of the array and cannot be acquired with the common method. To overcome this challenge, we propose a method that allows the robotic ultrasonic system to automatically self-adjust the positioning of the UT probe using a test block made of steel with defined geometric features as a target for referencing. For each of the six degrees of freedom, a scan and adjustment routine are established using the data acquired by the UT probe to update the TCP’s position and orientation in the robot control. Given a coarse pre-definition of the TCP and the known target test block, no human interaction is required while the system determines the optimum tool position and orientation. Part of this work will be used to improve and extend standards for robotic ultrasonic test systems, e.g. ISO 24647. T2 - 20th World Conference On Non-Destructive Testing CY - Inchean, South Korea DA - 27.05.2024 KW - Ultrasonic KW - Testing KW - Automation KW - Robotics KW - NDT 4.0 PY - 2024 AN - OPUS4-60565 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lecompagnon, Julien A1 - Ricci, M. A1 - Laureti, S. A1 - Ziegler, Mathias T1 - Practical study on the thermographic detectability of internal defects using temporally structured laser heating N2 - Modern laser systems have proven to be versatile heat sources for active thermographic testing applications. Compared to more traditional light sources, e.g. flash or halogen lamps, their output power can be easily modulated at high rates, allowing a wide variety of complex excitations to be realized. Although their total optical output power can be theoretically scaled to arbitrary values, the maximum output power is practically limited by many factors: the maximum power that the sample under test can absorb without altering the lighted surface itself, the trade-off between power density and inspected area, the cost of the laser system, etc. Furthermore, when working with spatial modulator systems, the output power could be limited to avoid provoking any damages on such devices. Nevertheless, to guarantee sufficient heating even for highly thermally conductive materials and/or deeply buried defects, the heating times can be extended, e.g., either by using step heating, long pulse thermography, or by lock-in thermography with a continuously modulated heating. However, for all these approaches, the ranging capabilities of the thermographic defect detection are reduced due to the limited frequency content of the excitation. To tackle this problem, i.e. to increase the excitation energy while preserving its frequency content, new approaches have been developed in the last two decades, among which the use of coded excitations combined with pulse-compression, and the use of multiple lock-in analysis or of a frequency modulated excitation signal. The challenges of such temporally structured heating techniques are manifold, for example, the DC component inherent in optical heating must be taken into account. In general, a wider frequency bandwidth or greater variability of the frequency components also means greater complexity for signal generation and data processing. In this paper, temporal structured excitation schemes with different degrees of complexity are compared on a high power laser system. T2 - 17th Quantitative InfraRed Thermography Conference (QIRT) CY - Zagreb, Croatia DA - 01.07.2024 KW - Thermography KW - Laser KW - NDT KW - Temporal structuring KW - Pulse-compression PY - 2024 AN - OPUS4-60563 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Skłodowska, Anna Maria A1 - Lay, Vera A1 - Baensch, Franziska A1 - Niederleithinger, Ernst A1 - Kühne, Hans-Carsten T1 - Acoustic emission monitoring for engineered barriers in nuclear waste disposal N2 - To safely dispose of nuclear waste in underground facilities, engineered barrier systems are needed to seal shafts and galleries. The material used in these barriers must be adapted to the host rock parameters. Shrinking and cracking must be avoided to provide a barrier with almost zero permeability. For repositories in salt rock environments, several types of salt concrete (SC) are possible construction materials. Within the project SealWasteSafe, we compared the behavior of an innovative alkali-activated material (AAM) with standard SC in their hydration and hardening phase. To monitor the microstructural changes within the two materials SC and AAM, acoustic emission (AE) signals have been recorded for up to ~250 days on 340-liter-cubic specimens. The phenomenon of AE is defined as the emission of elastic waves in materials due to the release of localized internal energy. Such energy release can be caused by the nucleation of micro-fracture, e.g., in concrete while curing or when exposed to load. The occurrence of AE events gives first rough indications of microstructural changes and potentially occurring cracking and thus, provides insights for structural health monitoring (SHM). The results show, that for the first 28 days after casting, less AE activity was detected in the AAM compared to SC. After 61 days, in the AAM material, the number of AE events exceeded those observed in the SC. However, the majority of the AE detected and located in AAM was related to surface effects, and not to microstructural changes or occurring cracks within the bulk volume. Additionally, the source location analysis indicated, that despite lower activity in SC, we observed some clustering of the events. In contrast, in AAM, the activity inside the specimen is randomly distributed over the whole volume. The monitoring results help to estimate the material’s sealing properties which are crucial to assess their applicability as sealing material for engineered barriers. T2 - 11th European Workshop on Structural Health Monitoring (EWSHM 2024) CY - Potsdam, Germany DA - 10.06.2024 KW - Acoustic emission monitoring KW - Nuclear waste repositories KW - Event localization KW - SealWasteSafe project PY - 2024 AN - OPUS4-60552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Skłodowska, Anna Maria A1 - Lay, Vera A1 - Baensch, Franziska A1 - Niederleithinger, Ernst A1 - Kühne, Hans-Carsten T1 - Long-term acoustic emission monitoring of a new alkali-activated material for sealing structures in nuclear waste repositories N2 - The crucial part of nuclear waste storage is the construction of sealing structures made of reliable, well-understood, and safe materials. Within the SealWasteSafe project, we compared the performance of an innovative alkali-activated material (AAM) and standard salt concrete (SC), as potential materials for sealing structures for nuclear waste repositories. Two 340-liter-cubic specimens were studied for up to ~250 days by a multisensory monitoring setup. Specifically, the long-term acoustic emission monitoring aimed to analyze the development of microstructural changes within materials. The monitoring analysis showed fewer acoustic emission events in AAM compared to SC in the first 61 days. After approximately two months of monitoring, the number of AE events in AAM significantly exceeded the number of events in SC. The analysis showed, however, that the increased AE activity was mainly caused by surface effects of the AAM material and not by the formation of cracks within the material. This contribution presents the use of acoustic emission analysis, both in the time and frequency domains, for monitoring and characterization of materials with potential use as engineering barriers for nuclear waste repositories. T2 - 186th Meeting of the Acoustical Society of America CY - Ottawa, Canada DA - 13.05.2024 KW - Acoustic emission monitoring KW - Alkali-activated material KW - SealWasteSafe KW - Nuclear waste repositories KW - Salt concrete KW - Sealing structures PY - 2024 AN - OPUS4-60551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Accuracy, Uncertainty, Probability of Detection N2 - This talk presents the concepts of measurement accuracy, uncertainty (in contrast to error analysis) an probability of detection for non-destructive testing. The relevant guidelines (GUM, Mil.Std.) are intrduced and practical examples given. T2 - USES2 Training Week 2 CY - Berlin, Germany DA - 24.06.2024 KW - Uncertainty KW - Pod KW - Measurements PY - 2024 AN - OPUS4-60467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Evans, Alexander A1 - Serrano-Munoz, Itziar A1 - Schröder, Jakob A1 - Mishurova, Tatiana A1 - Roveda, Ilaria A1 - Sprengel, Maximilian A1 - Fritsch, Tobias A1 - Ulbricht, Alexander A1 - Kromm, Arne A1 - Bruno, Giovanni T1 - Diffraction based residual stress analysis for laser powder bed fusion alloys N2 - Laser Powder Bed Fusion (PBF-LB/M) is a layer wise metal additive manufacturing (AM) technology, which enables significant advancements of component design, leading to potential efficiency and performance improvements. However, the thermal cycles inherent to the process comprising large localized thermal gradients and repeated melting and solidification cycles leads to the generation of high magnitude residual stresses. These residual stresses can be detrimental both during manufacturing of components and in subsequent application. Therefore, a deep understanding of the influence of process parameters on the residual stresses are crucial for efficient manufacturing and safe application. The experimental characterization of these residual stresses is therefore crucial and can provide a reliable baseline for simulations of both the process and applications. Diffraction-based methods for residual stress analysis using penetrating neutrons and high energy X-rays enable non-destructive spatially resolved characterization of both surface and bulk residual stresses. However, the unique microstructural features inherent to the process can challenge some of our assumptions when using these methods. These challenges include the determination of a stress-free reference, the use of correct elastic constants (both SCEC and DEC) and the influence of surface roughness, texture, and porosity on residual stresses. This presentation will detail recent insights and recommendations for the characterization of residual stresses in a range of PBF-LB/M metallic alloys (Fe, Ni, Al and Ti) T2 - 11th edition of the European Conference on Residual Stress (ECRS11) CY - Prague, Czech Republic DA - 03.06.2024 KW - Residual stress KW - Additive manufacturing KW - Laser Powder Bed Fusion KW - Diffraction PY - 2024 AN - OPUS4-60443 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -