TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus T1 - Humidity response analysis of optical fibers with hygroscopic coatings based on Lamé’s equations N2 - Optical fibers with hygroscopic coatings are widely used for humidity sensing, where the coating expands upon absorbing water, inducing strain in the fiber. This strain is then used to determine humidity. However, previous studies have oversimplified the strain generation process. A comprehensive three-dimensional model of the mechanical interaction between the coating and the fiber is built based on Lamé’s equations. An analytical expression for the induced strain is derived. The proposed model predicts larger humidity-induced strain compared to the reported ones, given the same Young’s modulus or coefficient of humidity expansion for the coating. Interestingly, the effect of coating thickness on strain response are quite similar for both methods. Experimental validation using fibers with a polyimide coating shows strong agreement with the theoretical predictions. T2 - 29th International Conference on Optical Fiber Sensors CY - Porto, Portugal DA - 26.05.2025 KW - Reflectometry KW - Distributed fiber sensing KW - Humidity sensors KW - Lamé’s equations KW - Optical fiber sensors KW - Structural health monitoring KW - Rayleigh scattering PY - 2025 SN - 978-1-5106-9188-9 DO - https://doi.org/10.1117/12.3060891 VL - 13639 SP - 1 EP - 4 PB - SPIE AN - OPUS4-63257 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Hicke, Konstantin T1 - Polarization-diversity-detection-based wavelength-scanning coherent-optical-time-domain reflectometer and its application for bus monitoring N2 - Although wavelength scanning coherent optical time-domain reflectometry (WS-COTDR) system is immune to fading effect, it suffers from occasional and localized large errors caused by the false peak in the correlation spectrum due to the large signal generated in the random interference of the backscattered light. Polarization diversity detection is applied to a standard WS-COTDR system to suppress large measurement errors. In this way, the orthogonally polarized components of backscattered light can be obtained and processed separately. Due to the birefringence of the sensing fiber, the components experience different interference processes, so the average of their correlation spectrum can suppress the false peaks and finally reduce the occurrence of larger errors. The effectiveness of the proposed method is validated in laboratory for monitoring of sinusoidal vibrations and in field for tracking the bus movement via a dark fiber. T2 - 29th International Conference on Optical Fiber Sensors CY - Porto, Portugal DA - 26.05.2025 KW - Traffic monitoring KW - Coherent optical time domain reflectometry KW - Distributed fiber sensing KW - Polarization diversity detection PY - 2025 SN - 978-1-5106-9187-2 DO - https://doi.org/10.1117/12.3060889 VL - 13639 SP - 1 EP - 4 PB - SPIE AN - OPUS4-63258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winkler, Nicolas P. A1 - Neumann, Patrick P. A1 - Schaffernicht, Erik A1 - Lilienthal, Achim T1 - Gas Distribution Mapping With Radius-Based, Bi-directional Graph Neural Networks (RABI-GNN) N2 - Gas Distribution Mapping (GDM) is essential in monitoring hazardous environments, where uneven sampling and spatial sparsity of data present significant challenges. Traditional methods for GDM often fall short in accuracy and expressiveness. Modern learning-based approaches employing Convolutional Neural Networks (CNNs) require regular-sized input data, limiting their adaptability to irregular and sparse datasets typically encountered in GDM. This study addresses these shortcomings by showcasing Graph Neural Networks (GNNs) for learningbased GDM on irregular and spatially sparse sensor data. Our Radius-Based, Bi-Directionally connected GNN (RABI-GNN) was trained on a synthetic gas distribution dataset on which it outperforms our previous CNN-based model while overcoming its constraints. We demonstrate the flexibility of RABI-GNN by applying it to real-world data obtained in an industrial steel factory, highlighting promising opportunities for more accurate GDM models. T2 - International Symposium on Olfaction and Electronic Nose (ISOEN) CY - Grapevine, TX, USA DA - 12.05.2024 KW - Gas distribution mapping KW - Spatial interpolation KW - Graph neural networks KW - Mobile robot olfaction PY - 2024 SN - 979-8-3503-7053-9 DO - https://doi.org/10.1109/isoen61239.2024.10556309 SP - 1 EP - 3 PB - IEEE AN - OPUS4-60103 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Hüllmann, Dino A1 - Winkler, Nicolas P. A1 - Lohrke, Heiko A1 - Lilienthal, A. J. ED - Lee, J. B. T1 - Outdoor Gas Plume Reconstructions: A Field Study with Aerial Tomography N2 - This paper outlines significant advancements in our previously developed aerial gas tomography system, now optimized to reconstruct 2D tomographic slices of gas plumes with enhanced precision in outdoor environments. The core of our system is an aerial robot equipped with a custom-built 3-axis aerial gimbal, a Tunable Diode Laser Absorption Spectroscopy (TDLAS) sensor for CH4 measurements, a laser rangefinder, and a wide-angle camera, combined with a state-of-the-art gas tomography algorithm. In real-world experiments, we sent the aerial robot along gate-shaped flight patterns over a semi-controlled environment with a static-like gas plume, providing a welldefined ground truth for system evaluation. The reconstructed cross-sectional 2D images closely matched the known ground truth concentration, confirming the system’s high accuracy and reliability. The demonstrated system’s capabilities open doors for potential applications in environmental monitoring and industrial safety, though further testing is planned to ascertain the system’s operational boundaries fully. T2 - 20th International Symposium on Olfaction and Electronic Nose CY - Grapevine, Texas, USA DA - 12.05.2024 KW - Aerial robot KW - TDLAS KW - Gas Tomography KW - Plume PY - 2024 SN - 979-8-3503-4865-1 DO - https://doi.org/10.1109/isoen61239.2024.10556071 SP - 1 EP - 3 PB - IEEE CY - USA AN - OPUS4-60107 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lohrke, Heiko A1 - Kohlhoff, Harald A1 - Neumann, Patrick P. ED - Lee, J. B. T1 - Robotic Scanning Absorption Spectroscopy for Methane Leak Detection: the Virtual Gas Camera N2 - This paper explores combining a gimbal-mounted tunable diode laser absorption spectroscopy (TDLAS) sensor and a video camera to create a virtual gas camera for methane leak detection. This provides a low-to-zero-cost extension of typical TDLAS gas tomography systems. A prototype setup mounted on a ground robot is evaluated. Results acquired using a simulated methane leak show the feasibility of the virtual gas camera, accurately detecting methane leaks by overlaying concentrations onto a visual image. While the acquisition time is significantly longer than for traditional gas cameras, potential enhancements are discussed. The study concludes that the virtual gas camera is feasible and useful, despite its longer acquisition time. It serves as a valuable software-only addition to typical TDLAS gas tomography systems, offering quickly-available on-site data augmentation for visual leak assessment at low-to-zero cost. T2 - 20th International Symposium on Olfaction and Electronic Nose CY - Grapevine, Texas, USA DA - 12.05.2024 KW - Mobile Robotic Olfaction KW - TDLAS KW - Gas Tomography KW - Gas Camera KW - Plume PY - 2024 SN - 979-8-3503-4865-1 DO - https://doi.org/10.1109/isoen61239.2024.10556012 SP - 1 EP - 3 PB - IEEE CY - USA AN - OPUS4-60109 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stührenberg, Jan A1 - Häusler, Felix S. A1 - Neumann, Patrick P. A1 - Dragos, Kosmas A1 - Smarsly, Kay ED - Francis, A. ED - Miresco, E. ED - Melhado, S. T1 - Multi-Agent-Based Swarm Gas Source Localization Using Nano Aerial Robots N2 - Gas source localization (GSL) is crucial for mitigating the impact of industrial accidents and natural disasters, for example finding leaks in oil and gas facilities or survivors in collapsed environments. Traditional GSL methods involving human intervention may be hazardous and time-consuming. Utilizing swarms of agile and cost-effective nano aerial robots holds the potential to enhance the safety and efficiency of GSL operations. This study draws inspiration from biological swarms, particularly colonies of social insects, to coordinate and optimize the performance of nano aerial robotic swarms. While most existing swarm GSL strategies assume gas concentration maxima to be in close proximity to actual gas sources, recent research has highlighted the importance of “bouts” as a more precise indicator of gas source proximity, considering the intermittency of gas distributions. In this paper, a swarm GSL strategy is introduced that incorporates bouts as indicators of source proximity, complemented by a bio-inspired pheromone communication system. Specifically, nano aerial robots are deployed as autonomous agents. Upon detecting bouts, the agents emit pheromone markers in an artificial environment, mimicking social insects. Using the concept of artificial potential fields, the agents either exploit the search space by following pheromone gradients or explore the search space. The proposed swarm GSL strategy is implemented and validated in a real-world experiment, conducted in an indoor environment with a single gas source. The experimental results demonstrate the capability of the swarm GSL strategy to perform effectively in indoor environments and that the intermittency of gas distributions is a better source proximity indicator than the mean concentration. It is concluded that this research may provide a methodological basis for improving gas source localization techniques and enhancing disaster response capabilities. T2 - ICCCBE 2024 CY - Montreal, Canada DA - 25.08.2024 KW - Gas source localization KW - Nano aerial robots KW - Mobile robotic olfaction KW - Bouts KW - Swarm robotics PY - 2025 SN - 978-3-031-87363-8 SN - 978-3-031-87364-5 DO - https://doi.org/10.1007/978-3-031-87364-5_28 SN - 2366-2557 VL - 2025 SP - 337 EP - 346 PB - Springer Nature Switzerland CY - Cham AN - OPUS4-63416 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Glötzl, R. ED - Boller, C. T1 - Development of a PMMA-POF based fiber optic inclinometer with smart transport and installation characteristics N2 - We present the state of our work concerning the development of a fiber optic inclinometer based on PMMA POF which provides distributed sensitivity regarding level, direction and location of deformation within critical ground structures. According to the demand for simple less expensive Installation and Operation of reliable sensor Systems a sensor concept has been developed and to our knowledge the first results of a PMMA POF based inclinometer prototype are presented in the following chapters. T2 - EWSHM'12 - 6th European workshop on structural health monitoring 2012 CY - Dresden, Germany DA - 03.07.2012 PY - 2012 SN - 978-3-940283-41-2 IS - Chapt. Optical Sensors SP - 411 EP - 416 CY - Berlin AN - OPUS4-26193 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ünal, Murat A1 - Ramge, Peter A1 - Kühne, Hans-Carsten T1 - Restoration of dalles de verre concrete glass windows with polymer modified repair mortars N2 - On concrete glazings done in the so called ‘Dalles de Verre’ technique, damages occur frequently in form of cracks, Chips and corroded reinforcement Steel. These glazings, mostly dating back to the 20* Century, are often of art-historical importance. This article focuses on the analysis of occurring damages and their causes and on the development of special repair mortars and repair concepts for these glazings, which were done in a recent research project. On several reference buildings compressive strength, reinforcement location and diameter, carbonation depth as well as moisture and salt profiles were determined exemplarily. At the time of the concrete glass Windows’ construction generally no sufficient care was taken for an adequate concrete covering of the reinforcement. Carbonation-induced reinforcement corrosion is therefore the main cause of the occurring damage. Standards dealing specifically with the repair of Dalles de Verre do not exist. Therefore the polymer modified repair mortar was development according to the German guideline “Protection and Repair of Concrete Structures” (RL SIB, 2001). However due to the unique boundary conditions ofthe Dalles de Verre glazings, thespecifications of this guideline alone are not sufficient, they need to be altered and amended. In the article the individual requirements on repair mortars for different application tasks are described. Furthermore, the development of the mortars’ formulations and of a test specimen for performance tests under realistic conditions is shown. T2 - ASPIC 2012 - 7th Asian symposium on polymers in concrete CY - Istanbul, Turkey DA - 03.10.2012 KW - Rehabilitation of concrete structures KW - Polymer modified repair mortar KW - Special test specimens KW - Durability KW - Carbonation KW - Cultural heritage PY - 2012 SN - 978-975-561-427-4 SP - 397 EP - 404 AN - OPUS4-26774 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ünal, Murat A1 - Kühne, Hans-Carsten ED - Alexander, M. G. ED - Beushausen, H.-D. ED - Dehn, F. ED - Moyo, P. T1 - Repair and restoration of 'Dalle de Verre' concrete windows N2 - On historically important concrete glazing damages occur frequently in form of cracks, chipping and corroded reinforcement. The present article focuses on the analysis of current damages and causes for damage and the development of repair concepts. The observation of compressive strength, carbonation depth, reinforcement layer and diameter as well as moisture and salt content profiles were determined on several reference objects. The carbonation-induced corrosion of the reinforcement was determined as the main cause of the present damage. The frequent occurrence of carbonation-induced corrosion is well-founded by the low concrete cover of the reinforcement. It is caused by the specific manufacturing process in the production of concrete-glass windows. Standards dealing especially with the repair of concrete glazing do not exist. Therefore appropriate repair and maintenance techniques in accordance with DIN EN 1504 and German guidelines for repair and protection of concrete (RL SIB 2001) were developed. The requirements for a repair mortar for these specific applications are described. Furthermore, the basics of cathodic corrosion protection with zinc are presented. T2 - 3rd International conference on concrete repair, rehabilitation and retrofitting III CY - Cape Town, South Africa DA - 03.09.2012 KW - Repair mortar KW - Concrete repair KW - Dalles de verre KW - Cultural heritage KW - Concrete glazing KW - Cathodic protection PY - 2012 SN - 978-0-415-89952-9 IS - Theme 2 SP - 607 EP - 612 PB - CRC Press CY - London, UK AN - OPUS4-26507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Muhasilovic, M. A1 - Vela-Wallenschus, Iris A1 - Trobok, Z. A1 - Petrovic, A. A1 - Mededovic, A. A1 - Gacanin, E. ED - Eberhardsteiner, J. T1 - Propper choice of model for turbulence treatment while research on flow in large-scale CFD-domains N2 - Especially in the societies, where some technical and scientific (in world - most common) approaches are not yet a vivid part of the organised economy and mechanism for scientific high-education, a CFD-based research on phenomena in (both gaseous and liquid) fluid-flow is one of the essential tools to be applied in causes of research and development. An interesting position has Bosnia and Herzegovina, whose scientists during the 1960ties have set some fundamental stones into the area of the Computational Fluid Dynamics while constructing this fine engineering and scientific tool for all of us in today's CFD-community. Presumed as "already developed" and in possible attempt to demonstrate the power of once made mathematical kits on the sophisticated scientific way, a certain approach in turbulence treatment within the modern CFD-tool is engaged. During this numerical research in mode of prospective engineering, a direct application is seen for the CFD-based exploring in the first two minutes of an accidental thermal load in a road-tunnel close to the city of Sarajevo. Performing the turbulence-treatment with the k-epsilon mathematical and numerical mechanism in mentioned CFD-toolkit, the case for forced longitudinal ventilation of the gaseous consequences done by the established simulated tunnel-fire was explored as well. For the CFDoriented research, that certainly varies in it's approaches and characteristics according to the nature of the explored large-scale domains, this CFD-based research-paper presents one further step towards the "best practice" in application of prospective engineering. T2 - ECCOMAS 2012 - 6th European congress on computational methods in applied sciences and engineering CY - Vienna, Austria DA - 10.09.2012 KW - Tunnel-fires KW - Prospective engineering KW - Confined fires KW - Traffic enclosures KW - k-epsilon treatment KW - LES-model KW - Large-scale CFD-domains PY - 2012 SN - 978-3-9502481-9-7 N1 - Geburtsname von Vela-Wallenschus, Iris: Vela, I. - Birth name of Vela-Wallenschus, Iris: Vela, I. SP - 1 EP - 20 AN - OPUS4-26879 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weltschev, Margit A1 - Werner, Jan A1 - Brandt, S. T1 - Compatibility of high density polyethylene grades with bioethanol-gasoline blends and biodiesel N2 - Biofuels including ethanol and biodiesel (fatty acid methyl ester) represent an important renewable fuel alternative to petroleum-derived transport fuels. Increasing biofuels use would have some benefits, such as a reduction in oil demand and greenhouse gas emissions, and an improvement in air quality. Materials compatibility is a major concern whenever the fuel composition is changed in a fuel System. The aim of this work is to study the interaction between high density polyethylene (HDPE) grades and biofuels such as E85 (fuel with 85 % ethanol) and biodiesel. 10 I jerricans made of two different polyethylene grades were filled with E85 and biodiesel and exposed to temperatures of 20°C and 40°C for one year. Tensile properties (tensile strength, breaking elongation and elasticity modulus) were determined in accordance with EN ISO 527-2 at 23±2 °C once a month, and Fourier Transform Infrared Spectroscopy (FTIR) was used to evaluate possible changes. The tensile properties of HDPE jerrican cuttings decreased, but not significantly, after immersion in E85 and biodiesel. In particular, the elasticity modulus of the polyethylene grades was reduced after exposure to biodiesel. Pin impression tests according to EN ISO 16101 were performed with test specimens of a HDPE grade in White Spirit, E85 and biodiesel. Measurements of the remaining tensile strength showed that biofuels had a stronger effect than White Spirit. The FTIR spectra of HDPE jerrican cuttings showed that immersion tests for one year with E85 at 20°C and 40°C only caused an increase in the peak of 1585 cm'1 (C=C Stretching vibrations) in the Chemical structure of HDPE. The FTIR spectra of HDPE jerrican cuttings showed that immersion tests for one year with biodiesel at 20°C and 40°C led to a broadening of the C=O peak of 1740 cm'1 and the appearance of the hydroxyl group at 3500 cm'1. Both results are explained by secondary degradation products of the polyethylene decomposition process caused by the temperature and unsaturated fatty acid content in the biodiesel since biodiesel decomposes quickly at elevated temperatures. The broadening of the C=O peak to 1740 cm'1 can be attributed to aldehyde carbonyl and ester Carbonyl groups mutually overlapping. Measurements of the melt flow rate (MFR) showed an increase in the MFR with immersion time in biodiesel due to the unsaturated fatty acid formed in the biodiesel. Diffusions of oxygen and rapeseed methyl ester increase the Chemical impact on polyethylene grades. T2 - EUROCORR 2012 - The European corrosion congress CY - Istanbul, Turkey DA - 09.09.2012 PY - 2012 SP - 1 EP - 12 AN - OPUS4-26534 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Schalk, H. A1 - Bienert, K. A1 - Molkenthin, A. A1 - Goldschmidt, Sebastian A1 - Niederleithinger, Ernst T1 - Quality control of hydrophobic coatings with an integrated marker element by laser-induced breakdown spectroscopy (LIBS) N2 - Reinforced concrete structures are affected by damage, caused e.g., by freeze-thaw effects or corrosion. Most damage processes are triggered by moisture transport including soluble substances. Hydrophobic coatings can be used for prevention of such damage, but quantitative on-site quality assurance methods are so far missing. A way to overcome this problem is to integrate marker substances into the coating, which can be detected by spectroscopic methods. Different types of marker elements have been tested. It can be shown that transition metals are best suited for the task. Currently a LIBS (Laser Induces Breakdown Spectroscopy) system is developed for the measurement of penetration depth and content of the hydrophobic coating via the marker element in the peripheral zone of concrete. T2 - 2nd International conference Micro Durability - Microstructural-related durability of cementitious composites CY - Amsterdam, The Netherlands DA - 11.04.2012 KW - Hydrophobierung KW - Laser Induced Breakdown Spektroskopie (LIBS) KW - Qualitätskontrolle PY - 2012 SN - 978-2-35158-129-2 N1 - Serientitel: RILEM proceedings – Series title: RILEM proceedings VL - PRO83 SP - 1 EP - 10 AN - OPUS4-27534 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gabler, M. A1 - Tkachenko, Viktoriya A1 - Küppers, S. A1 - Kuka, G.G. A1 - Habel, Wolfgang A1 - Milwich, M. A1 - Knippers, J. ED - Peters, K.J. ED - Ecke, W. ED - Matikas, T.E. T1 - Automatically produced FRP beams with embedded FOS in complex geometry: process, material compatibility, micromechanical analysis, and performance tests N2 - The main goal of the presented work was to evolve a multifunctional beam composed out of fiber reinforced plastics (FRP) and an embedded optical fiber with various fiber Bragg grating sensors (FBG). These beams are developed for the use as structural member for bridges or industrial applications. It is now possible to realize large scale cross sections, the embedding is part of a fully automated process and jumpers can be omitted in order to not negatively influence the laminate. The development includes the smart placement and layout of the optical fibers in the cross section, reliable strain transfer, and finally the coupling of the embedded fibers after production. Micromechanical tests and analysis were carried out to evaluate the performance of the sensor. The work was funded by the German ministry of economics and technology (funding scheme ZIM). Next to the authors of this contribution, Melanie Book with Röchling Engineering Plastics KG (Haren/Germany) and Katharina Frey with SAERTEX GmbH & Co. KG (Saerbeck/Germany) were part of the research group. T2 - Smart sensor phenomena, technology, networks, and systems integration 2012 (SPIE-Proceedings) CY - San Diego, USA DA - 26.04.2012 KW - Engineering KW - Fiber Bragg gratings (FBG) KW - Fiber reinforced polymers (FRP) KW - Optical fibers KW - Embedded sensors KW - Sensor-matrix interaction PY - 2012 SN - 978-0819490032 DO - https://doi.org/10.1117/12.915489 N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 8346 SP - 83460B-1 - 83460B-14 AN - OPUS4-27727 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph A1 - Hindersmann, I. A1 - Niederleithinger, Ernst T1 - Smart Bridge The duraBASt test bridge equipped with RFID-based sensors N2 - The duraBASt area at the highway intersection “Köln-Ost” is a large test field for road testing. It includes the duraBASt test bridge which is approximately 66 m long and 14.25 m broad. This bridge is part of the “road in the 21st Century” project and is equipped with several sensors for structural health monitoring. This feasibility study is carried out to investigate the prerequisites necessary for the constraction of intelligent bridges in the foture. Embedded sensors are able to measure quantities such as temperature, strain, moisture, corrosion, etc. In the presented work, the focus is set on passive RFID-based sensors. The communication and energy supply are realised by a mobile transmitter through the concrete cover. Hence, no cables or batteries are required. The sensors are designed to withstand the alkaline environment in concrete. Thus, moisture and corrosion values are measurable for several decades. T2 - 10th International Conference on Bridge Maintenance, Safety and Management CY - Online meeting DA - 11.04.2021 KW - RFID based sensors KW - Embedded sensors KW - Bridge Monitoring PY - 2021 DO - https://doi.org/10.1201/9780429279119-321 VL - 2021 SP - 2353 EP - 2358 PB - Taylor & Francis Group CY - London AN - OPUS4-53816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino A1 - Poltavtseva, Marina A1 - Mietz, Jürgen T1 - Electrochemical investigation of carbon-based conductive coatings for application as anodes in ICCP system of reinforced concrete structures N2 - Carbon‐based conductive coatings are complex composites, consisting of an organic or inorganic binder and conductive carbon components, for application as anodes in impressed current cathodic protection systems of reinforced concrete structures. The electrochemical properties of three coatings at different humidity and in saturated calcium hydroxide solution were studied by electrochemical methods, such as electrochemical impedance measurement, measuring of open circuit potential over time and galvanostatic polarization. The dissolved organic and inorganic carbons in electrolyte solution were quantified by using a photometric method. The structures of the coatings were investigated before and after the electrochemical tests by microscopy and scanning electron microscope/EDX analysis. The results of the electrochemical impedance measurements show that the tested coatings all have a relatively low resistance, which is between 100 and 200V. The binder and the surface porosity influence the degradation behavior of those coatings. Especially the organic binder reacts with the strong alkaline medium under dissolving of organic carbon. T2 - EUROCORR 2014 - European corrosion congress CY - Pisa, Italy DA - 08.09.2014 KW - Cathodic protection KW - Concrete KW - ICCP PY - 2014 SN - 978-3-89746-159-8 SP - O-7489, 481 EP - O-7489, 481 AN - OPUS4-31430 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino A1 - Mietz, Jürgen A1 - Burkert, Andreas T1 - Investigation of chloride-induced pitting corrosion of steel in concrete by a combination of electrochemical methods with X-ray tomography N2 - Steel in concrete is protected by the alkaline pore water environment and the resulting formation of a protective passive layer against corrosion. Adverse environmental conditions due to carbonation or chloride ingress can destroy the passive layer on the steel surface. Corrosion processes starting in those areas lead to uniform corrosion or local corrosion like pitting corrosion. In comparison to uniform corrosion pitting corrosion is a form of increased local corrosion and thus leads to a progressive reduction in cross-section of the reinforcing steel. The corrosion products are first absorbed by the pores of the concrete matrix, without causing visible external changes at the concrete surface. T2 - EUROCORR 2014 - European corrosion congress CY - Pisa, Italy DA - 08.09.2014 KW - Corrosion KW - Rebar KW - Chloride KW - Pitting corrosion PY - 2014 SN - 978-3-89746-159-8 SP - O-7207, 274-275 AN - OPUS4-31431 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hussels, Maria-Teresa A1 - Chruscicki, Sebastian A1 - Habib, Abdel Karim A1 - Krebber, Katerina T1 - Distributed acoustic fibre-optic sensors for condition monitoring of pipelines N2 - Industrial piping systems are particularly relevant to public safety and the continuous availability of infrastructure. However, condition monitoring systems based on many discrete sensors are generally not well-suited for widespread piping systems due to considerable installation effort, while use of distributed fibre-optic sensors would reduce this effort to a minimum. Specifically distributed acoustic sensing (DAS) is employed for detection of third-party threats and leaks in oil and gas pipelines in recent years and can in principle also be applied to industrial plants. Further possible detection routes amenable by DAS that could identify damage prior to emission of medium are subject of a current project at BAM, which aims at qualifying distributed fibre optic methods such as DAS as a means for spatially continuous monitoring of industrial piping systems. Here, first tests on a short pipe are presented, where optical fibres were applied directly to the surface. An artificial signal was used to define suitable parameters of the measurement system and compare different ways of applying the sensor. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, Ireland DA - 31.05.2016 KW - fibre-optic condition monitoring KW - distributed acoustic sensing (DAS) KW - pipeline monitoring KW - sensor application PY - 2016 SN - 978-1-5106-0219-9 DO - https://doi.org/10.1117/12.2236809 SN - 0277-786X VL - Vol. 9916 SP - Article Number: 99162Y PB - SPIE CY - Bellingham, Washington USA AN - OPUS4-37234 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino A1 - Burkert, Andreas A1 - Mietz, Jürgen T1 - Hydrogen evolution on galvanized rebar in fresh concrete with different chromate-reduced cements N2 - The reduction of the chromate contents in cements affects the electrochemical reactions of galvanized reinforcing steels in fresh concrete. It is important to investigate the critical conditions in the first hours following the pouring of the concrete. T2 - EUROCORR 2015 - European corrosion congress CY - Graz, Austria DA - 06.09.2015 KW - Hydrogen evolution KW - Concrete KW - Galvanized rebar KW - Reinforcement KW - Chromate PY - 2015 SP - paper 9_703 AN - OPUS4-34619 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zeps, Robert A1 - Ferrero, Fabio A1 - Kluge, Martin A1 - Schröder, Volkmar A1 - Spoormaker, T. T1 - Experimental investigation on the self-heating and decomposition of tetrafluoroethylene in a 100-dm³-reactor N2 - In the industry there is a lack of data on the Minimum Ignition Temperature of decomposition of tetrafluoroethylene in industrial sized equipment. In order to determine the Minimum Ignition Temperature of Decomposition of tetrafluoroethylene in large scale vessels, a facility was designed and constructed. Tests were carried out in a cylindrical reactor with a volume of 100 dm³ with initial pressures of 5 and 10 bar(a). In agreement with previous experiments with small scale cylindrical vessels, the Minimum Ignition Temperature of Decomposition of tetrafluoroethylene was observed to decrease with the initial pressure. The current paper describes the test setup and summarizes the experimental results achieved. The effect of the reactor adjustment (vertical or horizontal) is discussed. Moreover, simplified equations from the Semenov thermal explosion theory are used to attempt extrapolations of previous and current data on the Minimum Ignition Temperature of Decomposition of tetrafluoroethylene to other initial pressures and vessel volumes. T2 - Hazards XXIII Symposium CY - Southport, UK DA - 12.11.2012 KW - Tetrafluoroethylene KW - Self-heating KW - Large-scale reactor PY - 2012 SN - 978-0-85295-557-4 N1 - Serientitel: Symposium Series – Series title: Symposium Series N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, M. - Birth name of Kluge, Martin: Beckmann-Kluge, M. VL - 158 IS - Paper 08 SP - 48 EP - 55 AN - OPUS4-27056 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ferrero, Fabio A1 - Zeps, Robert A1 - Kluge, Martin A1 - Schröder, Volkmar A1 - Spoormaker, T. ED - Pierucci, S. ED - Klemes, J.J. ED - De Rademaeker, E. ED - Fabiano, B. ED - Buratti, S.S. T1 - The explosive decomposition of tetrafluoroethylene: large scale tests and simulations N2 - There is a lack of data on the self-ignition behaviour of tetrafluoroethylene (TFE) in industrial sized equipment. In order to assess the tendency of TFE for decomposition in large scale vessels, , a facility was designed and constructed. Tests were carried out in a cylindrical reactor with a volume of 100 L with initial pressures of 5 and 10 bar(a). The effect of the reactor adjustment (vertical or horizontal) was taken into account. The current work describes the test set up and summarizes the experimental results achieved. Furthermore, this paper reports on a numerical model for the prediction of the self -heating of TFE in closed vessels, which was previously developed for small scale reactors and has been here validated for larger dimensions with the experiments performed in the new facility. T2 - 14th International symposium on loss prevention and safety promotion in the process industries CY - Florence, Italy DA - 12.05.2013 KW - Tetrafluoroethylene KW - Self-heating KW - Large-scale reactor KW - Numerical simulation PY - 2013 SN - 978-88-95608-22-8 SN - 1974-9791 N1 - Serientitel: Chemical engineering transactions – Series title: Chemical engineering transactions IS - 31 SP - 1 EP - 6(?) PB - AIDIC, Associazione Italiana di Ingegneria Chimica CY - Milano AN - OPUS4-28549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habib, Abdel Karim A1 - Schalau, Bernd A1 - Schmidt, Dirk ED - Pierucci, S. ED - Klemes, J.J. ED - De Rademaeker, E. ED - Fabiano, B. ED - Buratti, S.S. T1 - Comparing different methods for calculating the gas dispersion N2 - When handling flammable and/or toxic liquids or gases, the gas dispersion following a release of substance is a scenario to be considered in the risk assessment to determine the lower flammability distance (LFD) and toxicity thresholds. In this work a comparison of different gas dispersion tools of varying complexity ranging from a simple Gaussian model over a boundary layer model (BLM) and a Lagrangian model to CFD (in this case ANSYS CFX v14) is presented. The BLM covers the special case of liquid releases with formation of a pool. It does not only solve the gas dispersion but also calculates the evaporating mass flow out of the pool. The simulation values are compared to each other and to experimental data resulting mainly from our own open air experiments covering the near field and carried out on the Test Site Technical Safety of BAM (BAM-TTS) for different release types (pool evaporation, gas release) and topologies. Other validation data were taken from literature and cover large scale experiments in the range of several 100 m. T2 - 14th International symposium on loss prevention and safety promotion in the process industries CY - Florence, Italy DA - 12.05.2013 KW - Gas dispersion KW - Simulation PY - 2013 SN - 978-88-95608-22-8 SN - 1974-9791 N1 - Serientitel: Chemical engineering transactions – Series title: Chemical engineering transactions IS - 31 SP - 1 EP - 6 PB - AIDIC, Associazione Italiana di Ingegneria Chimica CY - Milano AN - OPUS4-29587 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maierhofer, Christiane A1 - Krankenhagen, Rainer A1 - Röllig, Mathias A1 - Rehmer, Birgit A1 - Gower, M. A1 - Baker, G. A1 - Lodeiro, M. A1 - Aktas, A. A1 - Knaszovicka, L. A1 - Blahut, A. A1 - Monte, C. A1 - Adibekyan, A. A1 - Gutschwager, B. T1 - Characterisation of artificial defects in CFRP and GFRP sheets designed for energy applications using active thermography N2 - The increased use of fibre-reinforced plastic (FRP) composites for improved efficiency and reliability in energy related applications e.g. wind and marine turbine blades, nacelles, oil and gas flexible risers, also increases the demand for innovative non-destructive testing technologies. Thus, in order to achieve increased acceptance of suited and optimized non-destructive testing (NDT) methods in industry, the European Metrology Research Programme (EMRP) project ENG57 Validated Inspection Techniques for Composites in Energy Applications (VITCEA) deals with the development and validation of innovative NDT technologies. In this contribution, results concerning thermographic investigations at test specimens during tensile loading and active thermography testing after tensile loading are presented. Additionally, the determination of the optical properties (relative transmittance and directional spectral emissivity) of CFRP and GFRP test specimens is described. T2 - Conference QIRT 2016 CY - Gdansk, Poland DA - 04.07.2016 KW - Active thermography KW - CFRP KW - GFRP KW - Validation of methods PY - 2016 UR - http://qirt.gel.ulaval.ca/archives/qirt2016/papers/076.pdf DO - https://doi.org/10.21611/qirt.2016.076 SN - 2371-4085 SP - Paper 076, 527 EP - 536 CY - Quebec, Canada AN - OPUS4-37512 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kluge, Martin A1 - Kreißig, Michael A1 - Liebner, Christian A1 - Spoormaker, Tom ED - DeRademacher, E. ED - Schmelzer, P. T1 - Identifying hazardous conditions for rapid compression scenarios of chemically unstable gases in industrial scaled pipes N2 - The polymeric industry handles Tetrafluoroethylene (TFE) as basic material for polymer (PTFE) and co-polymer (PCTFE) production. As a chemically unstable gas, it can react in an explosive way, without the presence of any other gases. Once initiated such an exothermic reaction can propagate through the pipe system of a plant and might lead to massive damages and/or fatalities. Especially after maintenance parts of the pipe systems can be filled with TFE, nitrogen or air at pressures up to atmospheric conditions whereas connected parts of pipes might still contain TFE at operating pressure state. Many of the regarding pipes are separated by ball valves, which allow a fast opening procedure. Thereby fast compression of the gas can occur and lead to a massive temperature increase which might induce unwanted reactions. Former tests in laboratory scale described by Meyer (2009) allowed an ignition of a TFE/air system by rapid compression only for a set of sharp defined boundary conditions. First tests in the lower industrial scale were done by Ferrero et al. (2013), where an ignition at typical industrial operating conditions was initiated. The results of the tests indicated that the critical achievable compression temperatures strongly depend on the setup and therefore on the pipe diameter as well. Therefore the necessity of further tests has been pointed out. The original setup presented by Ferrero (2013), which represents the smallest typical industrial size with an inner diameter of 1.125”, was modified to withstand an explosive decomposition reaction and to avoid a deflagration to detonation transition. Different safety concepts as burst discs and time controlled cut-off valves had been tested and evaluated to optimize the experimental setup for reproducible test conditions. This allowed the systematic investigation of the rapid compression of TFE–systems for the first time in the described scale without serious damages after an ignition. In the donor pipe always TFE at high pressure and in the receiving pipe TFE, nitrogen or air were present at an absolute pressure ranging from 500 Pa to atmospheric pressure. The scope was to generate a “hazard diagram” in which the ignition probability in dependence of donor (high) pressure and the receiving (low) pressure is shown. Hazardous conditions can easily be determined. A reference method for the maximum achievable temperatures of non-reacting gas systems was created using an air/air-system. Thus reactive TFE-systems could be evaluated regarding additional exothermic effects. The final hazard diagram demonstrates that there is no sharp limit between a “safe” state and an “ignition” for a TFE/air-system. Rather a transition range exists, which decreases with rising donor pressure. An increased temperature in this range, sometimes combined with small pressure peaks in the profile, indicates first partial restricted reactions near the end flange. The more it gets closer to the “ignition” transition the more traces like soot or undefined solid fractions were found. A TFE/nitrogen- and a TFE/TFE-system could not be ignited at all. A description of the experimental tests as well as a detailed explanation of the hazard diagram will be presented. T2 - 15th International Symposium on Loss Prevention and Safety Promotion in the Process Industries and accompanying exhibition CY - Freiburg, Germany DA - 05.06.2016 KW - explosion KW - adiabatic compression KW - self ignition KW - plant safety KW - decomposable gas KW - fire PY - 2016 SN - 978-88-95608-39-6 DO - https://doi.org/10.3303/CET1648102 SN - 2283-9216 VL - 48 SP - 607 EP - 612 PB - AIDIC Servizi S.r.l. CY - Milano, Italy AN - OPUS4-37917 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weczera, S. A1 - Rhode, Michael A1 - Sunderkoetter, C. A1 - Plath, A. A1 - Jüttner, S. T1 - Laboratory experiments on press hardened steels in different delivered states exposed to hydrogen N2 - The legal and economical demands in the automotive industry lead to increasing efforts reducing the CO2 emissions. A way to achieve that goal is to reduce the total weight of the car and therefore the fuel consumption. With the application of high strength steels in car body manufacturing it is possible to decrease the sheet thickness of the used materials and therefore the weight of the automobile. Components made of high strength steels can be produced by cold forming as well as by hot forming. In high strength steel the hydrogen content plays a crucial role for the component behavior. It is known that the hydrogen diffusivity and solubility are based on several factors, for example increasing dislocation density by cold working processes, vacancies, chemical composition and grain boundaries. The understanding and the control of the interaction between hydrogen and the high strength press hardened steels is an important factor for the application of the materials. The scope of this work is the determination of hydrogen diffusion and permeability kinetics in press hardened steel samples. An electrochemical hydrogen permeation method was applied on boron-manganese steel grades with different rolling reduction in initial ferrite/pearlite matrix as well as for the as-quenched martensite microstructure. The diffusible hydrogen contents of the specimens were measured using the carrier gas hot extraction technique (CGHE). T2 - CHS2 2015 - 5th International conference on hot sheet metal forming of high-performance steel CY - Toronto, Ontario, Canada DA - 31.05.2015 KW - Automotive KW - High strength steel KW - Hydrogen KW - Measurement KW - Carrier gas hot extraction KW - Press-hardened KW - Martensite KW - 22MnB5 KW - Permeation PY - 2015 VL - 5 SP - 45 EP - 54 PB - Verlag Wissenschaftliche Scripten CY - Auerbach, Germany AN - OPUS4-33468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Oster, Simon A1 - Maierhofer, Christiane A1 - Mohr, Gunther A1 - Hilgenberg, Kai A1 - Ulbricht, Alexander A1 - Altenburg, Simon T1 - Investigation of the thermal history of L-PBF metal parts by feature extraction from in-situ SWIR thermography N2 - Laser powder bed fusion is used to create near net shape metal parts with a high degree of freedom in geometry design. When it comes to the production of safety critical components, a strict quality assurance is mandatory. An alternative to cost-intensive non-destructive testing of the produced parts is the utilization of in-situ process monitoring techniques. The formation of defects is linked to deviations of the local thermal history of the part from standard conditions. Therefore, one of the most promising monitoring techniques in additive manufacturing is thermography. In this study, features extracted from thermographic data are utilized to investigate the thermal history of cylindrical metal parts. The influence of process parameters, part geometry and scan strategy on the local heat distribution and on the resulting part porosity are presented. The suitability of the extracted features for in-situ process monitoring is discussed. T2 - Thermosense: Thermal Infrared Applications XLIII CY - Online meeting DA - 12.04.2021 KW - SWIR camera KW - Additive manufacturing (AM) KW - Selective laser melting (SLM) KW - Laser beam melting (LBM) KW - In-situ monitoring KW - Infrared thermography PY - 2021 SN - 978-1-5106-4324-6 DO - https://doi.org/10.1117/12.2587913 VL - 11743 SP - 1 EP - 11 PB - SPIE - The international society for optics and photonics AN - OPUS4-52535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brosig, Laura A1 - Horn, Wolfgang A1 - Pyza, Lars A1 - Jann, Oliver T1 - Applicability: Odour measurement based on ISO 16000-28 - enhanced determination of indoor air quality N2 - Odours might cause offensive nuisance and are under suspicion to be directly harmful to health. Surprisingly their assessment is by definition no part of the determination of indoor air quality (yet). As odours emit from building materials as well as from common consumer goods the users awareness increases continuously and demand for improved consumer protection raises. In comparison to well established methods for the determination of volatile organic compounds (VOC) in the air, there is little experience regarding the applicability, comparability and reproducibility of odour measurements. Considering this, the international and the German standardisation take into account odour assessment, e.g. ISO 16000-28 and VDI 4302-1. In Germany the AgBB-Scheme is a mandatory tool for the evaluation of building products and it is intended to implement odour measurement into it. Initially and essentially the newly developed method had to be put to test involving institutes that deal with VOC measurements. To test the applicability of the method an interlaboratory test was conducted. The results and identified potential improvements are presented in this study (Brosig, 2013). T2 - Indoor Air 2014 - 13th International conference on indoor air quality and climate CY - Hongkong, China DA - 07.07.2014 KW - Odour measurement KW - Perceived intensity KW - Hedonic tone KW - VOC KW - Building materials PY - 2014 SP - HP1079, 1 EP - 4 AN - OPUS4-31390 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Richter, Matthias A1 - Horn, Wolfgang A1 - Jann, Oliver A1 - Juritsch, Elevtheria A1 - Klinge, A. A1 - Roswag, E. A1 - Fontana, Patrick A1 - Miccoli, Lorenzo T1 - Indoor air emission tests of natural materials N2 - Emissions of building materials might have negative impact on human health and well-being. In the EU-funded research project H-House more than 30 natural materials (earthen dry boards and plasters, bio-based insulation materials made of wood, flax, reed, straw, etc.) used for renovation and refurbishment were tested regarding emissions of VOC, formaldehyde and radon. Different to ordinary emission tests on single materials this study focuses on the emissions from complete wall assemblies. Therefore, specially designed test chambers were used allowing the compounds to release only from the surface of the material facing indoors. The testing parameters were chosen in order to simulate model room conditions. The emission results were finally evaluated using the AgBB evaluation scheme, a procedure currently applied for the approval of flooring materials in Germany. T2 - 1st ICBBM - International conference on bio-based building materials CY - Clermont-Ferrand, France DA - 22.06.2015 KW - Emission testing KW - Natural materials KW - VOC KW - Formaldehyde KW - Radon PY - 2015 SN - 978-2-35158-154-4 SP - 641 EP - 643 AN - OPUS4-33609 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael A1 - Kromm, Arne A1 - Kannengießer, Thomas ED - Babu, S. S. ED - Bhadeshia, H.K. ED - Cross, C.E. ED - David, S.A. ED - DebRoy, T. ED - DuPont, J.N. ED - Koseki, T. ED - Liu, S. T1 - Residual stresses in multi-layer component welds T2 - 9th International conference on trends in welding research CY - Chicago, Illinois, USA DA - 2012-06-04 KW - Shrinkage restraint KW - Component welding KW - Submerged arc welding KW - Multi-run weld KW - Residual stresses KW - Reaction force KW - XRD KW - Large scale test PY - 2013 SN - 978-1-62708-998-2 SP - 48 EP - 54 PB - ASM international AN - OPUS4-27954 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kannengießer, Thomas A1 - Dabah, Eitan ED - Marquis, F. T1 - Energy dispersive synchrotron diffraction for in-situ analyses of hydrogen behavior in steels N2 - The extent of hydrogen embrittlement phenomenon is dependent on the interaction of hydrogen with the material i.e. diffusion behavior, lattice distortions, phase transformations and residual stresses developments. For the better understanding of the hydrogen interaction with the metal, possibilities of performing in-situ observations of the mentioned factors has to be accomplished. The EDDI (Energy Dispersive Diffraction) beamline at the BESSY II facility in Berlin provides this possibility and was used in order to investigate the aspects of this phenomenon in in-situ scale. The energy dispersive method entails a synchrotron X-ray white beam with a wide energy range (20–120 keV) which allows a fixed position of the sample and the detector, and combined with the high photons flux it allows a very short measurement time for obtaining a full scale X-Ray Diffraction patterns. In this contribution, the successful usage of high energy X-rays, applied for the first time for hydrogen behavior observations, provided the ability for evaluating in-situ the hydrogen diffusion behavior and the hydrogen interaction with stresses fields in the material. Steel samples were charged with hydrogen and examined by Synchrotron radiation. Two different methods were used in this research; the first is diffusible hydrogen concentration evaluation extracted from the lattice distortions, i.e. changes of the lattice parameter. The second is calculation of the residual stresses present in the sample and the interaction of hydrogen with them, using the known sin2ψ method. T2 - PRICM-8 - 8th Pacific rim international congress on advanced materials and processing CY - Waikoloa, Hawaii, USA DA - 04.08.2013 KW - Hydrogen embrittlement KW - Energy dispersive diffraction KW - Hydrogen diffusion KW - Residual stresses PY - 2013 SP - 3481 EP - 3487 AN - OPUS4-28975 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Lacraz, A. A1 - Kalli, K. A1 - Schukar, Marcus A1 - Krebber, Katerina ED - Berghmans, F. ED - Mignani, A. G. T1 - Strain sensing with femtosecond inscribed FBGs in perfluorinated polymer optical fibers N2 - In this work, the potential of fiber Bragg gratings (FBGs) in low-loss perfluorinated polymer optical fibers (PF-POFs) is explored. The FBG is femtosecond-inscribed in a commercial multi-mode (MM) PF-POF based on Cytop® polymer. Femtosecond inscription leads to creation of a highly saturated grating with a number of higher order reflection Peaks visible throughout the visible and near-infrared spectral region. For 2 mm long FBG having a pitch of 2.2895 μm, a total of nine higher-order MM reflection bands are visible spanning from 1548 nm (4th order) to 520 nm (12th order). Strain sensitivity was measured for 6 peak bands in 500-900 nm region, where relatively low cost CCD based spectrometers and broadband LEDs are available. Strain sensitivity increases almost linearly with increasing initial peak wavelength, growing from 4.82 ± 0.02 nm/% measured for 12th order peak at 517 nm to 8.12 ± 0.04 nm/% measured for 7th order peak at 883 nm. These values correspond to roughly 20 % higher sensitivity than silica FBGs exhibit in this spectral range. The gratings in PF-POFs combine the higher strain sensitivity and low-loss operation while maintaining the mechanical advantages of polymer optical fibers. Therefore, they hold a high potential for considerable broadening of polymer optical fiber Bragg gratings application range. T2 - Photonics Europe 2016, Optical Sensing and Detection IV CY - Brussels, Belgium DA - 03.04.2016 KW - Fiber Bragg gratings KW - Fiber optics sensors KW - Perfluorinated polymer optical fiber KW - Cytop KW - Strain sensitivity PY - 2016 SN - 978-1-5106-0144-4 DO - https://doi.org/10.1117/12.2225081 SN - 0277-786X VL - 9899 SP - 989911-1 EP - 989911-7 PB - SPIE AN - OPUS4-35926 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steffen, Milan A1 - Schukar, Marcus ED - Jaroszewicz, L.R. T1 - Integration of Cu-coated single-mode optical fiber into carbon/PEEK composite for distributed structural health monitoring based on Rayleigh backscatter reflectometry N2 - In this paper a technique for integrating copper coated silica optical fibers into AS-4/PEEK composite for Structural Health Monitoring (SHM) is presented. The integration steps are described in detail. X-ray and microscopic images indicate a successfully integrated optical fiber which does not seem to affect the fiber/matrix distribution around it. Optical backscatter reflectometry shows losses of approximately 2dBm-1 along the integrated parts of the optical fiber due to temperature induced shrinkage of the composite. T2 - EWOFS 2013 - 5th European workshop on optical fibre sensors CY - Kraków, Poland DA - 19.05.2013 KW - SHM KW - Optical KW - Fiber KW - Rayleigh KW - OFDR KW - Composite KW - Copper coating PY - 2013 DO - https://doi.org/10.1117/12.2025280 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - Paper 8794 - 181 SP - 879430-1 EP - 879430-6 AN - OPUS4-28627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilder, Constanze A1 - Schukar, Marcus A1 - Steffen, Milan A1 - Krebber, Katerina ED - López-Higuera, J.M. ED - Jones, J. ED - López-Amo, M. ED - Santos, J.L. T1 - Evaluating distributed fibre optic sensors integrated into thermoplastic composites for structural health monitoring N2 - Strain sensors used for structural health monitoring (SHM) must provide reliable measurement data during their entire service lifetime. To achieve this for fibre optic sensors integrated into composites, the integration of the sensor has to be adapted according to the process conditions. This paper describes the fabrication of thermoplastic composite samples with integrated distributed fibre optic sensors (DFOS) based on copper-nickel and polyimide coated silica optical fibres. The performance of these DFOS as SHM sensors is evaluated in terms of reliability by measurements derived from comparative measurements with resistance strain gauges and from fatigue tests with 10 million load cycles. T2 - OFS2014 - 23rd International conference on optical fibre sensors CY - Santander, Spain DA - 02.06.2014 KW - Distributed fibre optic sensor KW - Integrated sensor KW - Reliability KW - Structural health monitoring KW - Strain gauge KW - Optical frequency domain reflectometry KW - Fatigue test PY - 2014 DO - https://doi.org/10.1117/12.2058604 SN - 0277-786X SN - 1996-756X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 9157 SP - 91575Q-1 - 91575Q-4 AN - OPUS4-30861 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Thoralf A1 - Heyn, Andreas A1 - Fenker, M. A1 - Balzer, Martin T1 - Investigation on defect morphology and corrosion behaviour of TiMgN hard coatings on steel substrate N2 - Nitride hard coatings, such as Titanium nitride and chromium nitride coatings are widely used for applications focussing on wear protection and decorative purposes. Also these coatings are often applied on low alloyed steel substrates. The inevitable contact of the coated components with the environment through pores and coating defects bears the danger of corrosion of the steel substrate followed by further delamination of the coating and a loss of function of the component. A new attempt to increase the corrosion behaviour of those physically deposited hard coating systems is the implementation of magnesium. The positive effect of magnesium could be verified already electrochemically. Performed experiments on TiMgN have shown that corrosion resistance could drastically improved with increasing Mg content of the TiMgN up to 30 at% compared to steel substrates with applied titanium nitride hard coatings. Besides the clarification of the electrochemical and phenomenological effect of the magnesium on the corrosion behaviour, an additional aim of this work is the investigation of the coating defects, defect morphologies and their influence on the local corrosion behaviour. For this the incorporation of the magnesium and its effects on the coating material, the influence of coating growth related defects and the effect of the coating structure on the corrosion behaviour should be experimental examined by using innovative surface and material analysis methods such as FIB and TEM. Furthermore the evolution of the coating defects should be investigated by combing confocal microscopy with a new developed exposure test method using the electrochemical indication test KorroPad. The function of the KorroPad test, which was developed and patented [1] at the BAM for the detection of corrosion sensitive steel surfaces by indicating dissolution of iron ions [1], allows the detection and identification of critical coating defects for further microscopic investigation. Additional to that the KorroPad test simulates an accelerated exposure test by simultaneous absence of the disadvantages of typical short time exposure test like salt spray tests. Thus it allows a monitoring and analysis of the evolution of the critical coating defects and their influence on the local corrosion behaviour and the overall corrosion mechanisms. The results of this work should contribute to the development of new hard coatings with improved corrosion protection properties and also to a better understanding of the corrosion mechanisms of coated steel substrates. T2 - EUROCORR 2014 - European corrosion congress CY - Pisa, Italy DA - 08.09.2014 KW - Metallic coatings KW - Cathodic protection KW - Corrosion PY - 2014 SN - 978-3-89746-159-8 SP - O EP - 7473, 384 AN - OPUS4-31482 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Werner ED - Ziegler, M. ED - Bräu, G. ED - Heerten, G. ED - Laackmann, K. T1 - Long-term pull-out resistance and material properties of geogrids N2 - Geogrids, which are installed to prevent sliding failure on long and steep slopes, have to be safely anchored. The design and calculation of the anchorage is based on simple design rules. Basically, it is assumed that the pull-out resistance is proportional to the soil shear strength, the vertical load and the anchoring length and that the soil-reinforcement coefficient of proportionality as determined in pull-out tests is typically in the range between 0.5 and 1. Based on an extended version of a model for the soil-geogrid interaction, which was described by Ziegler and Timmers (2004) and Sieira et al. (2009), the physical assumptions and limitations of these rules are discussed. For those geogrids, for which the passive thrust mobilization of earth pressure by the displacement of the transversal or bearing force grid elements substantially contributes to the pull-out resistance, the mechanical strength of the junction between longitudinal and transversal elements is of crucial importance. The relation between mechanical properties of the junction, the flexibility of the longitudinal grid elements, the surface friction and the finally achieved pull-out resistance is exemplarily shown by a model calculation. It is included, that due to aging and creep the short-term junction strength may be significantly lower than the long-term strength. There is a certain critical pull-out resistance and an associated critical anchorage length. Both are determined by the strength of the junction embedded into the soil and are independent from the actually installed anchorage length. For a safe design it is not allowed to go beyond that limit. This requirement restricts the range of application of the common design rules. It follows that not only the long-term strength of the longitudinal elements has to be considered and quantified by reduction factors but also the long-term strength of junctions. These limitations have to be observed to achieve a safe design of the anchorage. Preliminary design rules are discussed. T2 - 10th International conference on geosynthetics CY - Berlin, Germany DA - 21.09.2014 KW - Geogrid KW - Anchoring KW - Junctions KW - Junction strenght KW - Sliding failure PY - 2014 SN - 978-3-9813953-9-6 SP - 1 EP - 8 AN - OPUS4-31575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Saathoff, F. A1 - Cantré, S. A1 - Müller, Werner ED - Ziegler, M. ED - Bräu, G. ED - Heerten, G. ED - Laackmann, K. T1 - Modified filtration criteria for non-woven geotextiles in landfill construction N2 - The German landfill ordinance includes a certification requirement for geosynthetics used in landfill liner and capping systems. The certification guidelines describe the basis for the design of geosynthetics used in landfill construction. According to the rules which are usually applied, the thickness of the filter geotextile has to be at least 30 times the characteristic opening size O90. Filter geotextiles which are often used in geocomposite drains have a mass per area of 200 g/m² and do not fulfill this requirement. In this paper modified filter criteria for geosynthetics are presented with a particular focus on These geotextile filters in geocomposite drains. T2 - 10th International conference on geosynthetics CY - Berlin, Germany DA - 21.09.2014 KW - Filtration criteria KW - Drainage KW - Geotextile KW - Non-woven KW - Landfill KW - Certification guidelines PY - 2014 SN - 978-3-9813953-9-6 SP - 1 EP - 7 AN - OPUS4-31578 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Thoralf A1 - Burkert, Andreas A1 - Heyn, A. A1 - Balzer, Martin A1 - Fenker, M. T1 - Investigation on the improved corrosion behavior of TiMgN hard coating on steel substrate T2 - EUROCORR 2015 - European corrosion congress CY - Graz, Austria DA - 06.09.2015 KW - Hard coatings KW - TiMgN KW - Corrosion PY - 2015 SP - paper 11.1_693 AN - OPUS4-34618 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Otremba, Frank A1 - Romero Navarrete, J. A. T1 - Assesing rail damage in turns due to lateral load transfer N2 - A testing procedure is proposed and used, to estimate the rail damage potentials of variations in both, the height of the cargo´s center of gravity and the railway car suspension´s spring constant. The experimental setup consist ed of a tilt table that slowl y exer ted an increasing lateral acceleration on a two axle bog ie type vehicle equipped with a spring supported container. The potential damaging effect derived from the resulting lateral load transfer, was assessed on the basis of the fourth power law. Results suggest that the cargo having a higher center of gravity could be more damagi ng to the outside rail when compared with the effect of the shorter center of gravity of the cargo, in a range from 0.94% to 3.17%, as a function of the spring constant of the suspension. Consequently and comparatively there would be a long term damaging effect on the rail when having a cargo with a high er center of gravity, so that specific cargo, having a high center of would be more aggressive to the infrastructure On the other hand for the range of time rate changes of the lateral acceleration, it was not found a consisten t trend regarding the effect of the value of the spring constant on the magnitude of the load transfers . T2 - IMECE 2024 CY - Portland, Oregon, USA DA - 17.11.2024 KW - Railway damage KW - Load transfer KW - Fourth power law KW - Experimental methods KW - Center of gravity KW - Tilt table KW - Suspension spring constant PY - 2024 SN - 978-0-7918-8869-8 SP - 1 EP - 4 PB - ASME AN - OPUS4-61785 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ahiboz, D. A1 - Andresen, Elina A1 - Manley, P. A1 - Resch-Genger, Ute A1 - Würth, Christian A1 - Becker, C. T1 - Enhanced photon upconversion using erbium-doped nanoparticles interacting with silicon metasurfaces N2 - Photon upconversion (UC) using trivalent erbium (Er+3) doped crystals is a promising concept to harness near infrared photons of the solar spectrum which cannot be directly absorbed by silicon solar cells. However, their UC efficiency at low-intensity 1 sun illumination is not relevant on device level so far. Exploiting giant near-field enhancement effects on metasurfaces is an appealing approach to enable efficient UC at low irradiance conditions. Here, we report on more than 1000-fold enhanced photon UC of NaYF4:Er+3 nanoparticles interacting with the near-fields supported by a silicon metasurface under 1550 nm excitation. T2 - 48th Photovoltaic Specialists Conference (PVSC) CY - Online meeting DA - 20.06.2021 KW - Nano KW - Nanomaterial KW - Upconversion nanoparticle KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Sensor KW - Excitation power density KW - Brightness KW - NIR KW - Mechanism KW - Modeling KW - Simulation KW - Energy transfer KW - Photonic crystal KW - Enhancement strategy PY - 2021 DO - https://doi.org/10.1109/pvsc43889.2021.9518495 SP - 1 EP - 3 PB - IEEE CY - Berlin AN - OPUS4-53786 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Biyikal, Mustafa A1 - Rurack, Knut T1 - Development of a Lab-on-a-Chip for the Detection of Nerve Agents with a Handheld Device N2 - The development of a Lab-on-a-Chip (LoC) is presented, which can detect reactive phosphorous compounds in the gas phase in combination with an optochemical hand-held sensor. The LoC prototype contains three pairs of sensing materials containing fluorescent indicator dyes in various carrier materials. By measuring the fluorescence response to phosphoryl chloride, a surrogate compound, the detection of chemical warfare agents (CWAs) in gas phase becomes possible within seconds, introducing a novel approach to CWA detection. T2 - 2023 IEEE SENSORS Conference CY - Vienna, Austria DA - 29.10.2023 KW - Lab-on-a-Chip KW - Nerve agents KW - Hand-held KW - Fluorescence KW - Toxic industrial chemicals PY - 2023 UR - https://ieeexplore.ieee.org/document/10325263 SN - 979-8-3503-0387-2 DO - https://doi.org/10.1109/SENSORS56945.2023.10325263 SP - 1 EP - 4 PB - IEEE CY - New York AN - OPUS4-59367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hakim, I. A1 - Laquai, René A1 - Schumacher, David A1 - Müller, Bernd R. A1 - Graja, P. A1 - Meyendorf, N. A1 - Donaldson, S. T1 - The Effect of Manufacturing Conditions on Discontinuity Population and Fatigue Fracture Behavior in Carbon/Epoxy Composites N2 - Carbon fiber composites have been increasingly used in aerospace, military, sports, automotive and other fields due to their excellent properties, including high specific strength, high specific modulus, corrosion resistance, fatigue resistance, and low thermal expansion coefficient. Interlaminar fracture is a serious failure mode leading to a loss in composite stiffness and strength. Iscontinuities formed during manufacturing process degrade the fatigue life and interlaminar fracture resistance of the composite. In his study, three approaches were implemented and their results were correlated to quantify discontinuities effecting static and fatigue interlaminar fracture behavior of carbon fiber composites. Samples were fabricated by hand layup vacuum bagging manufacturing process under three different vacuum levels, indicated High (-686 mmHg), Moderate (-330 mmHg) and Poor (0 mmHg). Discontinuity content was quantified throughthickness by destructive and nondestructive techniques. Eight different NDE methods were conducted including imaging NDE methods: X-Ray laminography, ultrasonic, high frequency eddy current, pulse thermography, pulse phase thermography and lock-in-thermography, and averaging NDE techniques: X-Ray refraction and thermal conductivity measurements. Samples were subsequently destructively serial sectioned through-thickness into several layers. Both static and fatigue interlaminar fracture behavior under Mode I were conducted. The results of several imaging NDE methods revealed the trend in percentages of discontinuity. However, the results of averaging NDE methods showed a clear correlation since they gave specific values of discontinuity through-thickness. Serial sectioning exposed the composite’s internal structure and provided a very clear idea about the type, shape, size, distribution and location of most discontinuities included. The results of mechanical testing showed that discontinuities lead to a decrease in Mode I static interlaminar fracture toughness and a decrease in Mode I cyclic strain energy release rates fatigue life. Finally, all approaches were correlated: the resulted NDE percentages and parameters were correlated with the features revealed by the destructive test of serial sectioning and static and fatigue values in order to quantify discontinuities such as delamination and voids. T2 - QNDE 2016 CY - Atlanta, GA, USA DA - 17.07.2016 KW - Carbon Fber Reinforced Polymers KW - Nondestructive Testing KW - X-ray Imaging KW - Ultrasound KW - Thermography PY - 2017 SN - 978-0-7354-1474-7 DO - https://doi.org/10.1063/1.4974661 SN - 0094-243X N1 - Geburtsname von Schumacher, David: Walter, D. - Birth name of Schumacher, David: Walter, D. VL - 1806 SP - UNSP 090017, 1 EP - 11 PB - AIP Publishing CY - Melville, NY, USA AN - OPUS4-39716 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kupsch, Andreas A1 - Hentschel, Manfred P. A1 - Lange, Axel A1 - Müller, Bernd R. T1 - X-ray dark field imaging N2 - A new kind of enhanced contrast X-ray imaging of weakly absorbing materials in dark field mode is presented. Samples such as plastics and biological tissue are a perpetual challenge for radiographic imaging. Recent innovative approaches such as Diffraction Enhanced Imaging (DEI), “phase contrast”, grating interferometry (Talbot-Lau), or Refraction Enhanced Imaging (REI) have in common that they yield enhanced contrast based on deflected X-rays. Here, we introduce a REI modification, which works with a slightly bent single crystal reflecting in Bragg geometry. The samples are placed upstream of the thin crystal within a parallel synchrotron beam. The crystal’s curvature creates a dark-field stripe in the transmission image, similar to the inverse of a Darwin-Prins rocking curve of plane crystals. The reflection condition is met better or worse as a steady function of incidence position. Refracted beam portions of sample interfaces appear bright on black stripes. The entire image is finally synthesized by multiple dark-field stripes. The technique is an alternative to the mentioned techniques. We demonstrate the technique’s advantage by examples of biological and technical microstructures. T2 - ECNDT 2014 - 11th European conference on non-destructive testing CY - Prague, Czech Republic DA - 06.10.2014 KW - X-ray refraction KW - Refraction enhanced imaging (REI) KW - Phase contrast KW - Radiology KW - Soft matter radiography PY - 2014 SN - 978-80-214-5018-9 SP - 1 EP - 7 AN - OPUS4-31971 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ramge, Peter A1 - Kühne, Hans-Carsten ED - Alexander, M. G. ED - Beushausen, H.-D. ED - Dehn, F. ED - Moyo, P. T1 - Investigations on the performance of concrete repair mortars in composite specimen tests N2 - In the scope of a recent research project investigations on the performance of repair mortars for concrete structures were carried out at BAM. One of the key points of the project was the systematic investigation on the mode of action of single constituents and their interactions with Special emphasis on their influence on the mortars’ stiffness and shrinkage behaviour. The mortar’s shrinkage can be the reason of many following problems, which can be a direct result, i.e. the damage of the bond interface caused by constraining forces, or an indirect result, such as an increase in carbonation Depth or chloride penetration due to shrinkage induced constraining cracks, which will subsequently lead to durability problems. Especially when repairing weak Substrate concretes the proper adjustments of the mortar’s stiffness and shrinkage behaviour to the properties of the concrete is of essential importance for functionality and durability of the repair task. T2 - 3rd International conference on concrete repair, rehabilitation and retrofitting III CY - Cape Town, South Africa DA - 03.09.2012 KW - Concrete repair KW - Repair mortar KW - Composite specimen KW - Shrinkage KW - Stiffness KW - Constraining forces KW - Constraining cracks PY - 2012 SN - 978-0-415-89952-9 IS - Theme 3 SP - 1046 EP - 1052 PB - CRC Press CY - London, UK AN - OPUS4-26505 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ramge, Peter A1 - Kühne, Hans-Carsten ED - Alexander, M. G. ED - Beushausen, H.-D. ED - Dehn, F. ED - Moyo, P. T1 - Development of repair mortars for the restoration of natural stone in cultural heritage N2 - Compared with concrete repair, the repair of natural stone is generally a similar task but at the same time very different. For listed buildings and monuments, historical, cultural and aesthetical interests become the ruling parameters. Especially from the demands of total reversibility of repair measures and strict prevention of the slightest original substance loss, which are not known in concrete repair, various restrictions are derived. From an aesthetical point of view, the same appearance as the original stone is desired for the mortar, whereas from a technical point of view, a monolithic behaviour of the repaired stone with homogeneous material properties would be favoured. This creates a need for a multitude of different property combinations and the whish for an independent adjustability of technical and aesthetical properties. A research project dealing with the development and optimisation of modular Stone repair mortars is currently carried out at BAM Federal Institute for Materials Research and Testing. T2 - 3rd International conference on concrete repair, rehabilitation and retrofitting III CY - Cape Town, South Africa DA - 03.09.2012 KW - Repair mortar KW - Natural stone KW - Stone restoration KW - Stone reprofiling KW - Modular system KW - Cultural heritage PY - 2012 SN - 978-0-415-89952-9 IS - Theme 3 SP - 882 EP - 887 PB - CRC Press CY - London, UK AN - OPUS4-26506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schälike, Stefan A1 - Wehrstedt, Klaus-Dieter A1 - Schönbucher, A. ED - Rademaeker, E. D. T1 - Flame heights of di-tert-butyl peroxide pool fires - experimental study and modelling N2 - The flame heights of di-tert-butyl peroxide (DTBP) pool fires with diameters between 0.03 m < d < 3 m are determined by means of visible images obtained by a VHS video recorder. The time-averaged Hav and maximum flame height Hmax were evaluated according to the intermittency criterion. For the relative time-averaged flame heights values in a range of 3.1 < Hav/d < 14.8 are obtained while the relative maximum flame heights are in a range of 3.5 < Hmax/d < 17.6. The experimental measurements were used to establish a new Froude number correlation. T2 - CISAP5 - 5th International Conference on Safety and Environment in Process and Power Industry CY - Milan, Italy DA - 03.06.2012 KW - Pool fire KW - Di-tert-butyl peroxide KW - Flame height KW - Froude number correlation PY - 2012 SN - 978-88-95608-17-4 DO - https://doi.org/10.3303/CET1226061 SN - 1974-9791 N1 - Serientitel: Chemical engineering transactions – Series title: Chemical engineering transactions IS - 26 SP - 363 EP - 368 PB - Assoziatione Italiana di Ingegneria Chimica CY - Milano AN - OPUS4-26012 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo A1 - Mosquera Feijoo, Maria A1 - Nolze, Gert A1 - Rizzo, F. ED - Militzer, M. ED - Botton, G. ED - Chen, L.-Q. ED - Howe, J. ED - Sinclair, C. ED - Zurob, H. T1 - Nano-sized precipitates in an Fe-13Cr alloy formed under oxidizing water vapor atmosphere N2 - Oxidation of a Fe –13Cr alloy under water vapor at 600°C produced a zone of nano-sized precipitation underneath the outside scale formed by iron oxides and Fe–Cr spinel. The majority of the spinel layer shows a fixed orientation relationship to the ferritic matrix: {1 0 0}α || {1 0 0}sp & <0 1 1>α || <0 0 1>sp . However, also the discovered precipitated particles are characterized by the same crystallographic orientation relationship to the respective ferritic parent grain. The habit of the precipitates is best described by a lath morphology with their main axis parallel to <1 0 0> of ferrite. Energy dispersive X-ray spectroscopy (EDX) and electron backscatter diffraction (EBSD) in scanning electron microscope (SEM) have been applied to characterize the oxide layer in micrometer scale. The clearly smaller precipitates were subsequently investigated by transmission electron microscopy (TEM). Specimens have been prepared by focused ion-beam (FIB) milling at an area previously characterized by EBSD. They cover the ferritic base material, but mainly the precipitation zone and the Fe–Cr spinel layer. Energy filtered selected area diffraction (SAD) in the conventional (C)TEM and high-angle annular dark field (HAADF) imaging in the scanning (S)TEM mode were employed in the characterization of the specimens. T2 - PTM 2015 - International conference on solid-solid phase transformations in inorganic materials CY - Whistler, BC, Canada DA - 28.06.2015 KW - Precipitation KW - Nano-crystals KW - Oxidation KW - Phase transformation KW - EBSD KW - TEM PY - 2015 SP - 379 EP - 386 AN - OPUS4-34444 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ramge, Peter A1 - Ünal, Murat A1 - Kühne, Hans-Carsten T1 - Polymer modified repair mortars for the restoration of natural stone in cultural heritage N2 - A research project dealing with the development and optimisation of modular repair mortars for natural stone is currently carried out at the BAM (Federal Institute of Materials Research and Testing). To provide the conservator with the best possible options to match colour, texture and technical requirements of the stone, the repairmortar System will be Setup on a modular basis. Different binder Systems are planned, which can be combined with different aggregate compositions and different pigments. The aim is to be able to modify the appearance of the mortar independent of ist mechanical properties. When working in the ränge of cultural heritäge, one specific demand is the Option of total reversibility of each repair task. In order to guarantee the reversibility and to ensure that the repair mortar does by no means induce any Damage to the original substance (e.g. by constraining forces), strength and stiffhess of the repairmortar have to be controlled and kept below the respective values of the original natural stone. On the other hand the mortar needs a certain abrasion resistance and durability. To accomplish all these requirements the use of polymer dispersions is very helpful, as they allow the production of low stiffhess mortars with at the same time relatively high flexural strength values. Also investigations on “alternative” modifications known from historical applications such as the use of casein are carried out. T2 - ASPIC 2012 - 7th Asian symposium on polymers in concrete CY - Istanbul, Turkey DA - 03.10.2012 KW - Repair mortar KW - Natural stone KW - Cultural heritage KW - Polymer cement mortar (PCC) KW - Stone restoration KW - Stone reprofiling KW - Casein PY - 2012 SN - 978-975-561-427-4 SP - 415 EP - 422 AN - OPUS4-26775 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schackmann, Oliver A1 - Márquez Reyes, Octavio A1 - Memmolo, Vittorio A1 - Lozano, Daniel A1 - Prager, Jens A1 - Moll, Jochen A1 - Kraemer, Peter T1 - Intelligent damage detection in composite pressure vessels under varying environmental and operational conditions N2 - Despite proven approaches available in the literature, structural health monitoring by ultrasonic guided waves under varying environmental and operational conditions is still challenging. The use of machine learning approaches is discussed in this work, considering the complex problem of experimental damage detection under varying load conditions in a composite overwrapped pressure vessel for hydrogen storage. Specifically, unsupervised methods originally developed for image and time series classification are combined with ensemble voting to conceive reliable damage detection technique. This enables the effective combination of the predictions of multiple transducer pairs, even with a limited number of strong individual classifiers. A performance demonstration of the technique is presented using a real damage scenario dataset. T2 - IEEE 12th International Workshop on Metrology for AeroSpace (MetroAeroSpace) CY - Napoli, Italy DA - 18.06.2025 KW - Guided ultrasonic waves KW - Structural health monitoring KW - Artificial intelligence KW - Hydrogen storage PY - 2025 SN - 979-8-3315-0152-5 DO - https://doi.org/10.1109/MetroAeroSpace64938.2025.11114628 SN - 2575-7490 SP - 608 EP - 613 AN - OPUS4-64894 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hille, Falk A1 - Schneider, Ronald A1 - Simon, Patrick A1 - Herrmann, Ralf A1 - Baeßler, Matthias ED - Döhler, Michael ED - Mélot, Adrien ED - Aenlle Lopez, Manuel T1 - System identification and model calibration of a steel road bridge N2 - The Bundesanstalt für Materialforschung und -prüfung (BAM), in cooperation with the Netherlands Organization for Applied Scientific Research (TNO), is working on a framework for integrating frequently updated structural models into an asset management process for bridge structures. A multi-span steel road bridge was selected as a test case for the development of this framework. In order for the structural model to represent the real behavior of the bridge with sufficient accuracy, model calibration is required. In this case, we have planned to calibrate the model based on the dynamic response of the bridge. To determine its dynamic properties, a multi-setup operational modal analysis was performed on one of the bridge spans. In parallel, a structural model of the span was developed based on the available design and service life information. Both eigenfrequencies and mode shapes were used as reference parameters to calibrate the model. A sensitivity analysis was performed to identify the most influential design parameters. Subsequently, a genetic algorithm was applied for minimizing the difference between measured and simulated characteristic responses. In the proposed paper, we summarize the measurements as well as the determination of the modal response of the bridge and describe the process of calibration of the structural model using the identified dynamic response. T2 - 11th International Operational Modal Analysis Conference (IOMAC 2025) CY - Rennes, France DA - 20.05.2025 KW - Bridge structure KW - Operational modal analysis KW - Model calibration PY - 2025 SN - 978-84-09-75120-4 SP - 114 EP - 121 PB - International Group of Operational Modal Analysis CY - Gijón, Spain AN - OPUS4-64416 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz A1 - Said, Samir A1 - Rohrmann, Rolf ED - Döhler, Michael T1 - Modal analysis of road and rail bridges for damage detection and resonance prediction N2 - In the 1980s, the Federal Institute of Material Research and Testing started with modal analysis measurements of some bridges before and after repair. For one of the bridges, a structural health monitoring was installed 1994 which is still working up to now. It has been modified and extended several times. The monitoring was extended from the critical span to three neighbouring spans. A modal analysis of the whole bridge with seven spans have been done three times, twice together with EMPA of Switzerland. Additional calibration measurements have been done and additional evaluation procedures have been implemented for the monitoring of the steadily increasing loads from the road traffic. Additional sensors were installed such as strain gauges, crack-width, and temperature sensors. The strong influence of the temperature on the natural frequencies has been studied over the years. Later, a temperature compensation has been established and a weak aging trend has been found in the monitoring data. Now, the bridge will be demolished and replaced by a new bridge. Some results of this long-term monitoring will be shown and possible damages (changes of the pre-stress or the support structure) will be discussed. A second application of modal analysis will be demonstrated: the prediction of the resonances due to passing trains. The response of a bridge to passing trains can be calculated in frequency domain as the multiplication of three spectra, the axle sequence spectrum of the train, the transfer function of the bridge, and the modal force spectrum of a single passing load. A resonance occurs if a maximum of the train spectrum coincides with the maximum of the bridge spectrum. The amplitude at this resonance is strongly influenced by the modal force spectrum which is identical to the frequency or wavenumber spectrum of the corresponding mode shape. Therefore, modal analysis from calculation, impact measurements, wind and train measurements are necessary for the prediction of the resonance occurrence and amplification. Examples of mode shape spectra for single or multi-span bridges with simply supported or continuous spans will be shown, and some relations between mode shapes and resonance amplifications will be concluded. T2 - 11th International Operational Modal Analysis Conference (IOMAC) CY - Rennes, France DA - 20.05.2025 KW - Bridge monitoring KW - Multi-span bridges KW - Damage detection KW - Resonance PY - 2025 SP - 39 EP - 46 PB - INRIA CY - Rennes AN - OPUS4-63473 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz A1 - Song, Jiaojiao T1 - Analysis of intact and damaged (floating) slab tracks by finite-element boundary-element models and by measurements N2 - The damage detection and repair control have become important tasks for slab tracks. Different intact and damaged slab tracks have been investigated theoretically and experimentally for train passages and hammer impacts. The following damages have been considered: The loss of contact between the sleeper and the track slab, between the track slab and the base slab, and between the base slab and the base layer. At first, a slab track with a gap between the track slab and the base layer has been calculated by the combined finite-element boundary-element method which correctly incorporates the behaviour of the infinite soil. The basic results are the track displacements of the rail, the track slab, and the base layer along the track which are caused by a single axle load. These solutions are properly superposed for to get the complete train load. The influence of track and soil parameters and of the track damage has been analysed. For the intact track, the compliance of the soil is dominant whereas the track bending stiffness becomes more important for the damaged track. By comparing the calculated results with the measurements, the length of the gap could be quantified. A slab track with a loose sleeper (without contact to the supporting track slab) was analysed by the transfer function between the displacements and the hammer force (receptance functions) where a resonance appeared in case of the damage. Differences between the different track elements confirmed the detection of the damage. A floating slab track with a thin rubber layer has been investigated for a possible gap between the base slab and the base layer. The behaviour of the intact track has been calculated by a wavenumber-domain method, and the same behaviour has been found in the measurements at several track sections, indicating that there is no damage. Finally, a floating slab track with steel springs and viscous fluid dampers has been measured in the Tongji laboratory. The modes of the floating track slab and the transfer function with corresponding resonances have been calculated and successfully compared with results from wheelset drop tests. T2 - Third International Conference on Rail Transportation (ICRT2024) CY - Shanghai, China DA - 07.08.2024 KW - Railway track KW - Damage KW - Vibration measurement KW - Finite element method KW - Boundary element method KW - Frequency response function KW - Moving load response KW - Floating slab track PY - 2025 SN - 978-0-7844-8594-1 SP - 591 EP - 600 AN - OPUS4-61267 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pelkner, Matthias A1 - Neubauer, Andreas A1 - Reimund, Verena A1 - Kreutzbruck, Marc ED - Thompson, D. O. ED - Chimenti, D. E. T1 - Local magnetization unit for GMR array based magnetic flux leakage inspection N2 - GMR sensors are increasingly used for magnetic surface inspection due to their high sensitivity and high spatial resolution. In case of simple planar or cylindrical shaped components, the GMR-based inspection procedure can be automated easily. We present GMR measurements of real fatigue cracks. In addition, we present a probe design using a local magnetization unit and commercially available GMR sensors. The design was carried out by means of finite-element method (FEM) simulations. Using the local probe we measured bearings containing artificial reference cracks of different depths and orientations. Cracks with a depth of 40 µm could be resolved with a signal-to-noise ratio better than 6. A further reduction of the measuring time can be obtained using a sensor array. For this purpose we present a study of the optimized size of the sensing GMR-layers for a NDE-adapted sensor array. The geometric sensor parameters were investigated through simulations of the magnetic flux leakage of surface cracks using an analytic model. T2 - 38th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Burlington, VT, USA DA - 17.07.2011 KW - GMR KW - Magnetic flux leakage KW - NDE KW - Sensor array PY - 2012 SN - 978-0-7354-1013-8 DO - https://doi.org/10.1063/1.4716332 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 1430 SP - 1005 EP - 1012 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-26107 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Yevtushenko, Oleksandra A1 - Carillo Salgado, I. T1 - Corrosion behavior of highly alloyed steels in artificial saline aquifer fluids containing carbon dioxide N2 - C02-corrosion on piping steels might cause problems during injection of flue gases for their storage in deep geological aquifer fluids. Therefore, the selection of appropriate piping steels is a key factor to increase safety and reliability of the Carbon Capture and Storage (CCS) technology, and to keep the process cost-efficient. Within the project COORAL (German acronym for “C02 purity for capture and storage”) corrosion studies on injection piping steels exposed to C02 and artificial brine with high Chloride concentration have been carried out. Corrosion of the injection pipe in C02-rich aquifer fluid may occur within the aquifer brine or when at injection interruptions the aquifer fluid may flow back into the injection pipe. Because of high salinity of aquifer brine and C02-corrosion an appropriate material ranking of injection piping steels should be made. Corrosion resistance of steels 1.4034, 1.4021, 1.4542, 1.4162 and 1.4562 was investigated in a corrosive environment using electrochemical and metallographic techniques. Electrochemical experiments in order to investigate the surface corrosion kinetics and polarization measurements in order to investigate localized corrosion phenomena have been carried out. Critical pitting potentials and repassivation potentials were determined by polarization curves of investigated materials and compared with measured corrosion potentials. Measured values were used in order to determine the suitability and performance of tested steels in C02-injection conditions. T2 - Latincorr 2014 - IX Latin American congress of corrosion CY - Medellín, Colombia DA - 28.10.2014 KW - Highly alloyed steels KW - Carbon dioxide KW - Pitting corrosion PY - 2014 SP - Paper 2445981, 1 EP - 5 AN - OPUS4-32746 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Weltschev, Margit ED - Wieland, H.-J. ED - Brockmann, S. T1 - Duplex steel's corrosion resistance compared to the austenite containing molybdenum N2 - In Germany the "BAM-List - Requirements for Tanks for the Transport of Dangerous Goods" is the basis for substance-related prototype approvals for tank Containers undertaken by the BAM - Federal Institute for Materials Research and Testing. Compatibility evaluations of selected metallic materials as well as of polymeric gasket and lining materials under the influence of approximately 7000 dangerous goods have been published in the BAM-List since 1989. The duplex Steel 1.4362 (2304, UNS S32304) was originally developed as substitute for the austenitic grades 1.4404 (316L, UNS S31603) and 1.4571 (316Ti, UNS S31635). Due to its characteristic profile this Steel was qualified for applications requiring high strength values at concomitant adequate corrosion resistance. Because of its lower content of the alloy elements nickel and molybdenum this duplex Steel is a cost-efficient alternative to the molybdenum containing austenite. Only a limited number of corrosion test results of 1.4362 under the influence of dangerous goods published in the BAM-List were available. Therefore test specimens of this Steel were exposed to selected corrosive substances. Due to the reduced alloy content a reduced corrosion resistance of the duplex Steel 1.4362 in acidic substances, such as formic acid, acetic acid and sulfuric acid, in comparison to the austenitic CrNiMosteels was observed. Tests in the alkaline medium showed a sufficient resistance. T2 - SCT2014 - 4th International conference on steels in cars and trucks CY - Braunschweig, Germany DA - 15.06.2014 KW - Duplexsteel KW - Dangerous goods PY - 2014 SN - 978-3-514-00813-7 SP - Paper 039, 316 EP - 323 PB - Verl. Stahleisen GmbH CY - Düsseldorf AN - OPUS4-31034 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Keserovic, Amela A1 - Bäßler, Ralph T1 - Geothermal systems of Indonesia - Influence of different factors on the corrosion performance of carbon steel API Q125 N2 - Among all of the existing electric power generation facilities, corrosion is considered to be the most severe on geothermal power plants. The focus of this research was set to evaluate the suitability of carbon steel API Q125 as a construction material on the geothermal sites Sibayak and Lahendong, Indonesia. The investigations were performed in the artificial geothermal brines under stagnant conditions by means of short-term electrochemical methods (Tafel extrapolation) and long-term exposure tests (up to 6 months). Furthermore, the influence of different parameters on the steels performance (temperature 70 °C, 100 °C and 175 °C, salinity 20 mg/L and 1,500 mg/L chlorides, pH 2 and 4) was assessed as well to ensure a “safer operating window” of a power plant. The results showed carbon steel API Q125 could be suitable for application in stagnant geothermal brines up to temperatures of 175 °C and a chloride concentration of 1,500 mg/L. Its applicability is limited in highly acidic environments (pH 2). T2 - World Geothermal Congress 2015 CY - Melbourne, Australia DA - 19.04.2015 KW - Corrosion KW - Carbon steel KW - Electrochemistry KW - Exposure KW - Sibayak KW - Lahendong PY - 2015 SN - 978-1-877040-02-3 SP - paper 27025, S. 1 EP - 8 AN - OPUS4-34751 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Brouwers, H.J.H. A1 - Kühne, Hans-Carsten A1 - Meng, Birgit ED - Wang, K. ED - Shah, S.P. ED - Khayat, K. T1 - Casting process improvement by optimization of mixture composition and high range water reducing agent modification N2 - Since its invention in the early 1990’s, self-consolidating concrete has never become well established in the ready-mix sectors worldwide. The reason for this can be mainly found in the fact that the sophisticated compositions are sensitive against changing environments. This lack of robustness can be attributed to the interaction between cement hydration reaction and high range water reducing agent (HRWRA). Understanding the relevant mechanisms that control the initial flow performance as well as the flow retention helps optimizing SCC mixtures that perform either steadily in one specific environment or that perform largely similarly at steadily changing environments. This paper depicts how HRWRAs interact with clinker and hydration phases and discusses the important role of the charge density of a polycarboxylic HRWRA in the way the rheology is affected. Based on rheometric results and observations of the Vicat setting times, it is shown that increasing charge densities of the HRWRA and decreasing water to powder ratios (w/p) reduce the flow retention and have lesser retarding effect on the setting. Based on the discussion, optimization procedures for the mixture composition and the HRWRA modification are suggested to achieve optimized performance for varying environmental situations or highest robustness for specific conditions. T2 - SCC 2013 - 5th North American conference on the design and use of self-consolidating concrete CY - Chicago, IL, USA DA - 12.05.2013 KW - Polycarboxylate KW - Cement hydration KW - Adsorption KW - Mixture composition KW - Environmental conditions PY - 2013 SP - 1 EP - 10 AN - OPUS4-28581 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten ED - Khayat, Kamal Henry T1 - Cusum charts for the control of the slump flow of self-compacting concrete in a steady production process N2 - Control chart systems are commonly used in quality management systems to keep production processes stable. The most efficient control chart systems are cumulated sums (cusum), which look at the deviations from a target value. Cusum charts react more rapidly on systematic changes in processes than other charts such as Shewhart charts, which look at the process values. The cusum method is often applied for compressive strength but it is particularly suitable if counteractions be taken immediately, like in the case of fresh concrete properties. The present study shows that regardless of the manipulation, a steady slump flow can be achieved only by adding supplementary superplasticizer in case of loss of flow and adding stabilising agent (ST) in case of increased flow if the V-mask indicates a systematic change. A reference SCC was artificially manipulated in order to achieve either increased or reduced flowability. Arithmetic mean values and standard deviations were determined experimentally without and after taking counteractions. These parameters were used for case studies of steady SCC productions based on normally distributed random values. For the indication of a systematic change, a standard V-mask was used. The results point out that productions with applied cusum methods were capable of keeping the slump flow deviation from the target in the order of magnitude of about 1% despite drastic manipulations, while productions without applied cusum method deviated up to 14% and more from the target slump flow value. T2 - 8th RILEM Symposium on Self-Compacting Concrete CY - Washington, USA DA - 15.05.2016 KW - Control charts KW - Cusum KW - Quality control KW - Rheology KW - Self-compacting concrete PY - 2016 SN - 978-2-35158-157-5 SP - 283 EP - 294 PB - RILEM Publications S.A.R.L. CY - Paris, France AN - OPUS4-36874 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - An, Q. A1 - Bäßler, Ralph A1 - Hertwig, Andreas A1 - Rehfeldt, Rainer A1 - Hidde, Gundula A1 - Otremba, Frank T1 - Investigation of Mechanical Stress and B10 Exposure on FKM Polymer N2 - Mechanical stress often accelerates the failure of polymer materials. The aim of this research is to study the interaction between the sealing material FKM and biofuels B10 (heating oil with 10% biodiesel). The mechanical stress test was carried out in a special apparatus. Both mechanical and non-mechanical stress tests were conducted on specimens at 20, 40, and 70 °C for 28 days to document changes in mass, volume, and tensile properties. Both increasing temperature and mechanical stress have a significant effect on the tensile strength of the FKM polymer when exposed to B10. The combination of increasing temperature and mechanical stress induced rupture within 2 h. It was also established that FKM polymer with pre-exposure in B10 survived longer during mechanical stress compared to specimens exposed only to air. With the support of infrared (IR) spectroscopy, we were able to confirm the penetration of B10 into the FKM polymer. T2 - TMS 2024 Annual Meeting & Exhibition Teilnahme mit Präsentation CY - Orlando-Florida / USA DA - 03.03.2024 KW - Biofuels KW - Sealing materials KW - Mechanical stress KW - Change in tensile properties PY - 2024 SN - 978-3-031-50349-8 DO - https://doi.org/10.1007/978-3-031-50349-8_108 SP - 1253 EP - 1261 PB - Springer CY - Orlando-Florida / USA AN - OPUS4-59638 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Schmidt, C. A1 - Alves, H. T1 - Suitability of Nickel-based alloys and titanium for applications in acids at 200 °C N2 - In the literature there are not much data available to describe the corrosion behavior of titanium, nickel alloys and special stainless steels in acids at high temperature, in particular above the boiling point. Therefore, a laboratory testing program was performed with two titanium alloys (grade 2 - UNS R50400 and grade 12 - UNS R53400) to obtain corrosion data in formic acid, acetic acid, phosphoric acid, polyphosphoric acid, p-toluene sulfonic acid and lactic acid at 200 °C. Results were compared to previously published ones obtained on alloy 31 (UNS N08031), alloy 59 (UNS N06059) and B-2 (UNS N10665). From the results it can be concluded that titanium does not always Show better corrosion resistance than Ni-based alloys, Alloy 59 was the best choice for formic and acetic acids at temperatures of 200°C. Both Ti-alloys are resistant in acetic acid. Some slight differences were observed for formic acid, where Ti grade 2 is only resistant up to a 20 % solution and grade 12 in concentrated acid too. The phosphoric acid is extremely corrosive and none of the investigated materials was resistant. In the diluted acid (5 %) only Ti grade 12 is resistant, whereas in 1 % solution all investigated materials withstand. Alloy B-2 and alloy 59 showed the best behavior in polyphosphoric acid. In 30 % concentrated p-toluene sulfonic acid at 200 °C all alloys tested were unsuitable. In very diluted acid (0.1 %) both Ti-alloys and the other three alloys behaved well. In lactic acid at 180 °C increased corrosion underneath deposits was detected; the best performance was observed for alloy 59 and Ti grade 2. T2 - VDM Symposium "Nickel alloys, titanium and zirconium in the chemical process industry" CY - Frankfurt am Main, Germany DA - 17.06.2015 KW - Titanium grade 2 (UNS 50400) KW - grade 12 (UNS 53400) KW - Alloy 59 (UNS N06059) KW - Alloy 31 (UNS N08031) KW - Alloy B-2 (UNS N10665) KW - Inorganic acids KW - Organic acids KW - Corrosion PY - 2015 SP - paper 3 AN - OPUS4-34752 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ramge, Peter A1 - Kühne, Hans-Carsten A1 - Meng, Birgit ED - Grantham, M. ED - Mechtcherine, V. ED - Schneck, U. T1 - Influence of selected aspects of the mixture proportioning on the performance of repair mortars N2 - Due to the large number of individual constituents, the mixture modification of repair mortar is a complex task. It is almost impossible to change an individual property without influencing other mortar properties. Most properties can be altered by several different measures, which may vary in effectiveness, side effects and cost efficiency. In the presented paper, special attention is paid to the prevention of shrinkage induced constraining cracks, as this is crucial for the durability and service life of a concrete repair task. On the basis of the parameter studies it is shown how it may be beneficial, in certain cases, to accept the worsening of some general properties if by this measure another property, which is essential for the individual application task, can be enhanced significantly. Due to the complexity of the constituents' interactions in repair mortars, even apparently conflicting combinations of admixtures may become necessary. T2 - Concrete solutions 2011 - 4th International conference on concrete repair CY - Dresden, Germany DA - 26.09.2011 KW - Repair mortar KW - Concrete rehabilitation KW - Repair systems KW - Polymer cement concrete (PCC) KW - Sprayed polymer cement concrete (SPCC) PY - 2012 SN - 978-0-415-61-622-5 SP - 451 EP - 459 PB - Taylor & Francis CY - London AN - OPUS4-24567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rogge, Andreas A1 - Thiele, Marc ED - Strauss, ED - Frangopol, ED - Bergmeister, T1 - Damage evolution in concrete under high compressive cyclic loadings N2 - The aim of this project is to get deeper insight into the fatigue behaviour of concrete under cyclic compressive loading. It focuses on the evaluation and modelling of the entire damage process during life-cycle by means of various non-destructive measuring techniques. In numerous tests on cylinders h/d = 30/10 cm under different cyclic loading conditions, the crack development and the damage evolution are monitored using acoustic emission analysis and ultrasonic velocity measurement. The final aim will be the definition of a damage descriptor D based on experimental observations, which can be implemented into a numerical model on a meso-mechanical level. T2 - IALCCE 2012 - 3rd International symposium on life-cycle civil engineering CY - Vienna, Austria DA - 03.10.2012 KW - Concrete KW - Cyclic loading KW - Fatigue KW - Damage PY - 2013 SN - 978-0-415-62126-7 SP - 1307 EP - 1313 PB - CRC Press CY - Boca Raton, Fla. AN - OPUS4-26845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohwetter, Philipp A1 - Kielau, T. A1 - Lothongkam, Chaiyaporn A1 - Heidmann, G. A1 - Habel, Wolfgang ED - Liao, Y. ED - Jin, W. ED - Sampson, D.D. ED - Yamauchi, R. ED - Chung, Y. ED - Nakamura, K. ED - Rao, Y. T1 - All fibre-optic simultaneous detection of optical and acoustic emission from partial discharges in silicone elastomer N2 - In high-voltage facilities of power stations and transmission networks, discharge activities leading to catastrophic failure can occur. Early detection of partial discharges (PD) in polymeric insulations of HV cable terminations and joints is therefore increasingly important. This paper describes a monitoring methodology to detect PD activity in silicone elastomer by two independent fibre-optic sensor types. Fluorescent fibre-based sensors are sensitive to plasma optical emission already at the onset of PD while an acoustic fibre-optic sensor responds to acoustic emission from the PD during its progression. The sensitivities of both sensor types are compared, and it is demonstrated that they provide complementary information for fibre-optic sensor-based monitoring of high-voltage cable accessories.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only. T2 - OFS2012 - 22nd International conference on optical fiber sensors CY - Beijing, China DA - 15.10.2012 KW - Fiber optic sensors KW - Plasma KW - Sensors KW - Fibre-optic condition monitoring KW - Partial discharge KW - Acoustic emission KW - High-voltage breakdown KW - Silicone elastomer KW - Stress cone KW - Fluorescent fibre KW - High voltage cable accessories PY - 2012 DO - https://doi.org/10.1117/12.974941 SN - 0277-786X SN - 1996-756X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 8421 SP - 8421B9-1 EP - 8421B9-4 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-27323 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lichtenstein, D. A1 - Meyer, Th. A1 - Böhmert, L. A1 - Sieg, H. A1 - Juling, S. A1 - Thünemann, Andreas A1 - Lopies, I. E. A1 - Bräuning, A. A1 - Lampen, A. T1 - Evidence for particle-specific and coating-related uptake of silver nanoparticles N2 - Present data indicate that the quantification of silver nanoparticle internalization revealed a clear particle-specific and coatingrelated uptake. Furthermore, a high amount of silver nanoparticles is taken up in cell models of higher complexity. Thus, an underestimation of particle effects in vitro might be prevented by considering cell models with greater proximity to the in vivo situation. T2 - 52nd Congress of the European-Societies-of-Toxicology (EUROTOX) CY - Seville, Spain DA - 04.09.2016 KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Silver PY - 2017 DO - https://doi.org/10.1016/j.toxlet.2016.06.1938 SN - 0378-4274 VL - 258 SP - S267 EP - S267 PB - Elsevier Ltd. AN - OPUS4-40936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Moufid, M. A1 - Tiebe, Carlo A1 - El Bari, N. A1 - Bartholmai, Matthias A1 - Bouchikhi, B. T1 - Advance in electronic nose technology developed for the detection and discrimination of ethanol, ammonia, and hydrogen sulfide gases N2 - This work focuses on the design and fabrication of low-cost and fast-response of an electronic nose (E-nose) based on semiconductor gas sensors, for discriminating some synthetic gases such as ammonia (NH3), ethanol (C2H5OH), and hydrogen sulfide (H2S). Additionally, the capability of separating different concentration levels of each considered gases was checked. Dataset treatment of E-nose by using Principal Component Analysis (PCA) showed a good discrimination of the different synthetic gases. Furthermore, perfect classification was reached of different concentration levels of the analysed gases by using Discriminant Function Analysis (DFA). In the light of these results, it could be stated that the developed E-nose system constitutes an inexpensive, rapid, simple to use, and efficient tool for synthetic gases detection. T2 - IEEE International Symposium on Olfaction and Electronic Nose (ISOEN) CY - Aveiro, Portugal DA - 29.05.2022 KW - Electronic nose KW - Metal oxide semiconductor KW - Chemometric techniques KW - Environmental analysis PY - 2022 SN - 978-1-6654-5860-3 DO - https://doi.org/10.1109/ISOEN54820.2022.9789636 SP - 1 EP - 3 AN - OPUS4-56574 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blanchard, R. A1 - Holtappels, Kai A1 - Kluge, Martin A1 - Schildberg, H.-P. A1 - Zeps, Robert ED - de Rademacher, E. ED - Schmelzer, P. T1 - Sizing of Explosion Pressure Relief using the Efflux Function N2 - Determination of deflagration venting requirements in chemical/process plants is usually carried out using well established standards employing an empirically based formula. However, this formula is shown to have severe shortcomings, especially in the range of low KG-values, where either negative or inconceivably large venting areas can be predicted. Due to these shortcomings a method has been developed using the efflux function for gases as a basis to predict the mass flow through a vent opening in a vessel during an internal explosion. The simulated rise in pressure due to the internal explosion is quantitatively determined from the KG-value, with the mass flow through the vent opening in the vessel resulting from the pressure difference between the vessel and its surroundings. This enables the maximum overpressure as a function of the pressure relief surface area to be predicted. The method takes into account the temperature of the efflux gases and turbulence enhancement brought about by the venting process. In the following paper explosion pressure relief experiments are described and the results from these experiments are compared to predictions from the efflux method. It is shown that by adjusting the assumed turbulence which evolves during the venting process, the reduced explosion pressure can be reasonably well reproduced. T2 - 15th International Symposium on Loss Prevention and Safety Promotion in the Process Industries and accompanying exhibition CY - Freiburg, Germany DA - 05.06.2016 KW - Deflagration KW - Explosion KW - Pressure relief KW - Venting KW - Efflux PY - 2016 SN - 978-88-95608-39-6 DO - https://doi.org/10.3303/CET1648082 SN - 2283-9216 VL - 48 SP - 487 EP - 492 PB - AIDIC Servizi S.r.l CY - Milano, Italy AN - OPUS4-37918 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Faber, M.H. A1 - Thöns, Sebastian ED - Miraglia, S. ED - Vrouwenvelder, A.C.W.M. ED - Steenbergen, R.D.J.M. ED - Van Gelder, P.H.A.J.M. T1 - On the value of structural health monitoring N2 - Health monitoring has, over the last 2-3 decades, become a topic of significant interest within the structural engineering research community, but also in the broader areas of civil and mechanical engineering. Whereas the merits of Structural Health Monitoring (SHM) are generally appreciated in qualitative terms there has, as of yet, not been reported much fundamental research on the quantification of the benefit of SHM. The present paper addresses the quantification of SHM with basis in the Bayesian pre-posterior decision analysis. The starting points are historical and recent developments in the fields of SHM and the quantification of value of information as well as the identification of typical situations in structural engineering in which SHM has the potential to provide value beyond its costs. Subsequently, the theoretical framework which allows for the quantification of the value of information collected through SHM Systems is developed and elaborated. It is shown how the value of information can be quantified to support the assessment and optimization of decisions on whether and how to implement SHM. To illustrate the use of the developed theoretical framework for evaiuating the benefit of SHM an example is provided. The example addresses the life-cycle benefit maximization for offshore jacket structures subject to fatigue crack growth utilizing monitoring of near field fatigue stresses as a means of optimizing risk based inspection and maintenance strategies. T2 - 22nd ESREL conference - Safety, reliability and risk analysis: Beyond the horizon CY - Amsterdam, The Netherlands DA - 29.09.2013 PY - 2014 SN - 978-1-138-00123-7 SP - 2535 EP - 2544 PB - Taylor & Francis AN - OPUS4-29894 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hu, Wei-Hua A1 - Thöns, Sebastian A1 - Said, Samir A1 - Rücker, Werner ED - Cunha, A. ED - Caetano, E. ED - Ribeiro, P. ED - Müller, G. T1 - Resonance phenomenon in a wind turbine system under operational conditions N2 - A prototype of wind turbines in 5 megawatt dass was built and tested at the first German offshore wind energy test fteld in the North Sea. In order to investigate dynamic behaviors under a complex state of loads, a continuous dynamic monitoring System was implemented by Federal Institute for Material Research and Testing (BAM). It recorded structural responses and environmental/operational variables from November 2007 to October 2009. This paper presents significant resonance phenomenon due to the interaction in the tower-nacelle System under operational conditions. Modal parameters are automatically estimated by the poly reference Least Square Complex Frequency domain (p-LSCF) method. Campbell plot demonstrates that a three-blade passage frequency and its multiples f3n match with the natural frequencies of the wind turbine System in several modal Orders. The damping estimates decrease and the Vibration amplitude increase significantly. A control System is necessary to minimize the excessive vibrations. T2 - EURODYN 2014 - 9th International conference on structural dynamics CY - Porto, Portugal DA - 30.06.2014 KW - Wind turbine KW - Tower-nacelle system KW - Resonance KW - Continuous dynamic monitoring KW - Automated operational modal analysis PY - 2014 SN - 978-972-752-165-4 SN - 2311-9020 SP - 3619 EP - 3626 AN - OPUS4-32970 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thöns, Sebastian A1 - McMillan, D. T1 - Condition monitoring benefit for offshore wind turbines N2 - As more offshore wind parks are commissioned, the focus will inevitably shift from a planuing, construction and warranty focus to an Operation, maintenance and investment payback focus. In this latter case, both short-term risks associated with wind turbine component assemblies, and longterm risks related to structural integrity of the Support structure, are highly important. This research focuses on the role of condition monitoring to lower costs associated with short-term reliability and long-term asset integrity. This enables comparative estimates of life cycle costs and reduction in uncertainty, both of which are of value to Investors. T2 - PMAPS 2012 - 12th International Conference on Probabilistic Methods Applied to Power Systems CY - Istanbul, Turkey DA - 10.06.2012 KW - Condition monitoring KW - Offshore wind KW - Operation KW - Risk KW - Life cycle KW - Cost KW - Cost benefit analysis KW - Offshore wind turbine KW - Operation management KW - Structural integrity management PY - 2012 SP - 37 EP - 42 PB - Istanbul Technical University CY - Instanbul, Turkey AN - OPUS4-26117 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald A1 - Thöns, Sebastian A1 - Straub, D. ED - Strauss, A. ED - Frangopol, D.M. ED - Bergmeister, K. T1 - Probalistic fatigue crack growth modeling for reliability-based inspection planning N2 - The fatigue deterioration modeling for welded steel structures subjected to high cycle fatigue is presented in the current document. The aim of this paper is to formulate approaches based on actual Research results for the phases fatigue crack initiation, fatigue propagation and fatigue failure. The physical characteristics of the approaches are discussed in combination with the associated uncertainties and the probabilistic modeling of this time variant reliability problem. The fatigue deterioration modeling documented here serve as a basis for a reliability-based approach to inspection planning. T2 - 3rd International symposium on life-cycle civil engineering CY - Vienna, Austria DA - 03.10.2012 PY - 2012 SN - 978-0-415-62126-7 SP - 319 EP - 326 PB - CRC Press AN - OPUS4-27067 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Gradt, Thomas T1 - Tribological behaviour of graphite filled polyimide composites in hydrogen environment N2 - The tribological behaviour of graphite filled polyimide composites against steel (AISI 52100) was investigated in air, vacuum and hydrogen environments. Composites consist of two polyimides filled with different types and amount of graphite. Friction and wear measurements were performed at 0.2m/s and 3.1MPa at ambient temperature. Worn surfaces and morphology of the material transfer on the steel counter-face were investigated by optical microscopy and SEM analyses. Results reveal that the polyimide structure has an important influence on the friction behaviour of graphite filled composites in hydrogen environment. T2 - ECCM16 - 16th European conference on composite materials CY - Seville, Spain DA - 22.06.2014 KW - Polyimide composites KW - Graphite KW - Hydrogen environment KW - Vacuum PY - 2014 SN - 978-84-616-9798-4 SP - Paper 1137, 1 EP - 8 AN - OPUS4-31181 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tahri, K. A1 - Tiebe, Carlo A1 - Bougrini, M. A1 - Saidi, T. A1 - El Alami-El Hassani, N. A1 - El Bari, N. A1 - Hübert, Thomas A1 - Bouchikhi, B. T1 - Determination of safranal concentration in saffron samples by means of VE-tongue, SPME-GC-MS, UV-vis spectrophotometry and multivariate analysis N2 - An experimental investigation has been carried out to characterize and discriminate seven saffron samples and to verify their declared geographical origin using a voltammetric electronic tongue (VE-tongue). The ability of multivariable analysis methods such as Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA) to classify the saffron samples according to their geographical origin have been investigated. A good discrimination has reached using PCA and HCA in the VE-tongue characterization case. Furthermore, cross validation and Partial Least Square (PLS) techniques were applied in order to build suitable management and prediction models for the determination of safranal concentration in saffron samples based on SPME-GC-MS and UV-Vis Spectrophotometry. The obtained results reveals that some relationships were established between the VE-tongue signal, SPMEGC-MS and UV-Vis spectrophotometry methods to predict safranal concentration levels in saffron samples by using the PLS model. In the light of these results, we can say that the proposed electronic system offer a fast, simple and efficient tool to recognize the declared geographical origin of the saffron samples. T2 - IEEE Sensor 2015 CY - Busan, South Korea DA - 01.11.2015 KW - Chemometrics KW - Voltammetric electronic tongue KW - SPME-GC-MS KW - UV-vis Spectrometry KW - Saffron KW - Geographic differentiation PY - 2015 SN - 978-1-4799-8202-8 VL - CFP15SEN-USB SP - 68 EP - 71 PB - IEEE CY - Piscataway AN - OPUS4-36545 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heinke, D. A1 - Gehrke, N. A1 - Ludwig, F. A1 - Steinhoff, U. A1 - Pankhurst, Q. A. A1 - Lüdtke-Buzug, K. A1 - Thünemann, Andreas A1 - Johansson, Ch. T1 - NanoMag - Standardization of Analysis Methods for Magnetic Nanoparticles N2 - The NanoMag project brings together various leading experts in magnetic nanoparticle synthesis as well as nanoparticle analysis and characterization from research institutes, companies, universities and metrology institutes that will perform cutting-edge research and develop applications in the field of magnetic particles. This work is supported by the European Commission Framework Programme7 under the NanoMag project [grant agreement no 604448]. T2 - 2015 5th International Workshop on Magnetic Particle Imaging (IWMPI) CY - Istanbul, Turkey DA - 26.03.2015 KW - nanoparticles PY - 2015 UR - http://www.nanomag-project.eu/ SN - 978-1-4799-7269-2 SN - 978-1-4799-7271-5 DO - https://doi.org/10.1109/IWMPI.2015.7107065 VL - 2015 SP - P39 PB - IEEE AN - OPUS4-37324 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Hongyi A1 - Hofmann-Böllinghaus, Anja ED - Makovická Osvaldová, L. ED - Hasburgh, L. E. ED - Das, O. T1 - Applying experimental determined kinetic parameters to the simulation of vegetation fire in the Fire Dynamics Simulator N2 - Although intense wildfire research has been done in the US and in Australia, it cannot be transferred directly to the situation in Europe as the local vegetation has a significant influence on the fire spread. The EU-funded project TREEADS and the so-called German pilot within the project are concentrating on wildfire in Europe. Extensive experimental research is done on local vegeta-tion in Germany and the experimental results are used to adjust the Fire Dynam-ics Simulator (FDS) to local vegetation as a fuel in the calculations. The particle model and the boundary fuel model are developed for the simulation of forest fires. Both models require the kinetic input for the dehydration, pyrolysis, and char oxidation process. This three-step simplified model describes the basic fuel combustion kinetic. Most published simulations use the default kinetic input of pine needles from FDS user manual. To adjust the simulation to local vegetation, the corresponding kinetic parame-ters have been experimental investigated. Samples of pine needles, moss and other falling leaves were collected, air dried and grinded into powder. The TG analysis of all these samples were done under different heating rate of 5, 10 and 20K/min. The activation energy and the corresponding pre-exponential factor were calcu-lated. The results show that fire spread depends significantly on the vegetation and comparison with small scale experiments show good agreement using the new kinetic parameters. The new model is applied to a larger scenario and will be compared to the results of large-scale experiments for further validation of the model. T2 - Wood and Fire Safety 2024 CY - Štrbské Pleso, Slovakia DA - 12.05.2024 KW - Forest KW - Simulation KW - FDS KW - Vegetation fire KW - Fire Dynamics Simulator KW - Kinetic parameters PY - 2024 SN - 978-3-031-59177-8 DO - https://doi.org/10.1007/978-3-031-59177-8_45 SP - 389 EP - 396 PB - Springer CY - Cham AN - OPUS4-60252 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stoppel, Markus A1 - Taffe, Alexander A1 - Wiggenhauser, Herbert A1 - Kurz, J. H. A1 - Boller, C. ED - Grantham, M. ED - Mechtcherine, V. ED - Schneck, U. T1 - Automated multi-sensor systems in civil engineering for condition assessment of concrete structures N2 - Infrastructure is subject to continuous ageing. This has given life cycle management of infrastructure an important role. Therefore an increasing demand for reliable inspection and monitoring tools is noticeable. A combination of different non-destructive test methods is often necessary to receive reliable results for material characterization, flaw detection and the determination of component specific geometry Parameters. Regarding concrete structures thickness measurements are combined with flaw detection and additional Information about reinforcement and tendon ducts is required. Therefore, a multi-sensor measurement approach is necessary with a high degree of automation. Otherwise a time consuming succession of manual measurements has to be performed which would prevent practical applications. A modular control and data acquisition approach is described and the application of two different automated measurement devices is shown. The BetoScan System consists of a self-navigating mobile robot. The System is especially designed for the Investigation of reinforced concrete floors exposed to de-icing salts. The data acquisition of the OSSCAR System, a multi-sensor Scanner, is similar to the robot approach. These different applications are based on a similar kernel allowing the modular use of different contact and non-contact sensors. The described general concept of multi-sensor data acquisition and data analysis presented here is not limited to the field of civil engineering applications. T2 - Concrete Solutions 2011 - 4th International Conference on Concrete Repair CY - Dresden, Germany DA - 26.09.2011 KW - Multi sensor KW - Data aquisition KW - Assessment of concrete structures KW - Scanner KW - NDT PY - 2012 SN - 978-0-415-61-622-5 SP - 397 EP - 403 PB - Taylor & Francis CY - London AN - OPUS4-24659 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Andrade, M. A. B. A1 - Stindt, Arne A1 - Panne, Ulrich A1 - Riedel, Jens A1 - Adamowski, J. C. T1 - Numerical and experimental determination of the sound pressure distribution in single-axis acoustic levitators N2 - This paper presents a numerical and an experimental procedure to obtain the pressure field in single-axis acoustic levitators. Numerically, the pressure field is determined by a matrix method based on the Rayleigh integral that take into account the multiple wave reflections that occur between the transducer and the reflector. The numerical pressure field is compared with the acoustic pressure measured by an earplug microphone, that is connected to a hollow needle. The tip of the needle is moved by a µm translation stage through the field and the signal is recorded using a lock-in amplifier locked to the levitator frequency. The pressure field obtained numerically show good agreement with that obtained experimentally. T2 - 2012 IEEE International Ultrasonics Symposium (IUS) CY - Dresden, Germany DA - 07.10.2012 KW - Acoustic levitation KW - Matrix method KW - Pressure field PY - 2012 SN - 978-1-4673-4562-0 DO - https://doi.org/10.1109/ULTSYM.2012.0690 SP - 2754 EP - 2757 PB - Institute of Electrical and Electronics Engineers (IEEE) CY - Piscataway, NJ AN - OPUS4-32587 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Böllinghaus, Thomas A1 - Mente, Tobias T1 - Vermeidung von Rissen beim Schweissen von Rohrleitungen N2 - Schadensfälle in den letzten zehn Jahren mit teilweise katastrophalen Folgen belegen, dass der Vermeidung von Rissen beim Schweißen von Rohrleitungen besondere Aufmerksamkeit zu schenken ist. In der Analyse solcher Schäden ist zu unterscheiden, ob die Risse bereits während oder kurz nach der schweißtechnischen Fertigung der Rohrkomponenten oder während des anschließenden Betriebes entstanden sind. Im vorliegenden Beitrag wird sich vor allem auf die Vermeidung einer Heiß- und Kaltrissbildung beim Schweißen von Rohrleitungen konzentriert und es werden weitere Forschungsperspektiven abgeleitet. T2 - DVM-Tag 2011 - Bauteilzuverlässigkeit - Schäden und ihre Vermeidung CY - Berlin, Germany DA - 04.05.2011 KW - Rissvermeidung KW - Heißrissbildung KW - Wasserstoffunterstützte Kaltrissbildung (HACC) KW - Pipelineschweißungen PY - 2011 SN - 0946-5987 N1 - Serientitel: DVM-Bericht – Series title: DVM-Bericht IS - 678 SP - 81 EP - 90 AN - OPUS4-26113 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Röhsler, Andreas A1 - Sobol, Oded A1 - Nolze, Gert A1 - Unger, Wolfgang A1 - Böllinghaus, Thomas T1 - Use of time-of-flight secondary ion mass spectrometry for the investigation of hydrogen-induced effects in austenitic steel AISI 304L N2 - During the energy transformation from fossil fuels to renewable energy sources, the use of hydrogen as fuel and energy storage can play a key role. This presents new challenges to industry and the scientific community alike. The storage and transport of hydrogen, which is nowadays mainly realized by austenitic stainless steels, remains problematic, which is due to the degradation of mechanical properties and the possibility of phase transformation by hydrogen diffusion and accumulation. The development of materials and technologies requires a fundamental understanding of these degradation processes. Therefore, studying the behavior of hydrogen in austenitic steel contributes to an understanding of the damage processes, which is crucial for both life assessment and safe use of components in industry and transportation. As one of the few tools that is capable of depicting the distribution of hydrogen in steels, time-of-flight secondary ion mass spectrometry was conducted after electrochemical charging. To obtain further information about the structural composition and cracking behavior, electron-backscattered diffraction and scanning electron microscopy were performed. Gathered data of chemical composition and topography were treated employing data fusion, thus creating a comprehensive portrait of hydrogen-induced effects in the austenite grade AISI 304L. Specimens were electrochemically charged with deuterium instead of hydrogen. This arises from the difficulties to distinguish between artificially charged hydrogen and traces existing in the material or the rest gas in the analysis chamber. Similar diffusion and permeation behavior, as well as solubility, allow nonetheless to draw conclusions from the experiments. T2 - 21st International Conference on Secondary Ion Mass Spectrometry CY - Kraków, Poland DA - 10.09.2017 KW - AISI 304L KW - Hydrogen KW - ToF-SIMS KW - Austenitic stainless steel PY - 2018 DO - https://doi.org/10.1116/1.5013931 SN - 1071-1023 VL - 36 IS - 3 SP - Article 03F103, 1 EP - 6 PB - American Vacuum Society (AVS) AN - OPUS4-44840 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geoerg, Paul A1 - Rost, M. A1 - Krause, U. A1 - Hofmann-Böllinghaus, Anja T1 - Vergleichende Untersuchung zur Personensicherheit am Beispiel eines Seminarraumes N2 - Um den Anforderungen der Bauordnung an den Brandschutz für Gebäude gerecht zu werden, sind bauliche Anlagen so zu errichten und zu betreiben, dass der Entstehung eines Brandes und der Ausbreitung von Feuer und Rauch vorgebeugt, die Rettung von Menschen und Tieren sowie wirksame Löscharbeiten ermöglicht werden. Hierbei besteht, einer steigenden Komplexität sowie einem differenzierten Nutzungskonzept öffentlicher Gebäude geschuldet, häufig die Notwendigkeit von normativen Vorgaben abzuweichen und dennoch ein gleichwertiges Sicherheitsniveau nachzuweisen. Es werden Personensimulationsmodelle eingesetzt, die einerseits das Vorhandensein eines Schutzzielniveaus durch die Abbildungen von Personenbewegungen nachweisen können und andererseits durch Parametervariation eine szenarienabhängige Betrachtung ermöglichen. Der vorliegende Beitrag vergleicht die Ergebnisse einer kleinskaligen Evakuierungsübung mit drei mikroskopischen Personensimulationsmodellen und geht der Frage nach der Aussagekraft dieser Bewertungsmethode nach. Es zeigt sich, dass die alleinige Betrachtung absoluter Entleerungszeiten keine zuverlässige Beurteilungsgrundlage für das komplexe Schutzziel Personensicherheit darstellt. T2 - 4. Magdeburger Brand- und Explosionsschutztag / 3. vfdb-Workshop Brandschutzforschung CY - Magdeburg, Germany DA - 26.03.2015 KW - Evakuierung KW - Routenwahl KW - Fußgänger KW - Sicherheit KW - Simulation PY - 2015 SN - 978-3-00-048960-0 SP - 1 EP - 13 AN - OPUS4-33123 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfennig, Anja A1 - Schulz, S. A1 - Werlitz, T. A1 - Bülow, E. A1 - Wetzlich, S. A1 - Tietböhl, J. A1 - Frieslich, C. A1 - Kranzmann, Axel T1 - Influence of heat treatment on the corrosion of steels in CCS environment N2 - To predict the reliability and safety during the injection of compressed emission gasses - mainly containing CO2 - into deep geologica! layers (CCS-technoIogy, Carbon Capture and Storage), the influence of heat treatment on pit corrosion needs to be considered. In laboratory Experiments different heat treated steeis used as injection pipe with 13% Chromium and 0.46% Carbon (X46CrI3, 1.4034) and 0.2% Carbon (X20Crl3. 1.4021) as well as 16% Chromium Steel XöCrNiCuNb 16-4 (1.4542) were tested. The samples were exposed up to 1 year to the distinct synthetic aquifer environment saturated with technical CO2 at a flow rate of 3 l/h. The corrosion rate generally does not exceed 0.03 mm/year. Pits with maximum pit heights around 300 µm were obtained for hardened X20Crl3 with martensitic microstructure. The least amount of pits is found on X46Crl3. The higher carbon content in, X46Crl3 (0.46% C), results in a lower amount ofpits compared to X20Crl3 (0.20%). T2 - TMS 2012 - 141st Annual Meeting & Exhibition CY - Orlando, FL, USA DA - 11.03.2012 KW - CCS KW - Carbon capture and storage KW - Corrosion KW - Steel KW - Pipeline KW - Carbon KW - Heat treatment KW - CO2-storage PY - 2012 SN - 978-1-11829-607-3 VL - 1 IS - Supplemental Proceedings SP - 103 EP - 110 PB - John Wiley & Sons CY - Hoboken, NJ, USA AN - OPUS4-28007 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grützner, Stefan A1 - Rehmer, Birgit A1 - Fedelich, Bernard A1 - Mosquera Feijoo, Maria T1 - Deformation modeling and lifetime prediction of Ni-base gas turbine blade alloys under TMF-conditions N2 - Under cyclic thermomechanical loading conditions, various effects such as strain accumulation, creep damage, ageing, fatigue etc. may occur in the material of a gas turbine blade. Depending on the loading conditions, all these effects contribute to reduce the lifetime of the component. Subject of the present work is the development of a lifetime model able to discriminate between the different damage mechanisms, as well as the development of a material model to describe the mentioned effects and thus providing the input data for lifetime prediction. T2 - ASME Turbo Expo 2014 - GT2014 CY - Düsseldorf, Germany DA - 16.06.2014 KW - Ni-base super alloy KW - Viscoplastic KW - Ratcheting KW - Creep KW - Strain induced ageing KW - Fatigue KW - Oxidation damage PY - 2014 SN - 978-0-7918-4576-9 SP - GT2014-26332, 1-7 AN - OPUS4-30962 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Keserovic, Amela A1 - Sobetzki, Joana A1 - Sarmiento Klapper, Helmuth A1 - Dimper, Matthias T1 - Laboratory evaluation of metallic materials for geothermal applications N2 - In the last years, geothermal power has become a reliable and significant energy source. Because service conditions in geothermal facilities from deeply located aquifers are usually critical in terms of corrosion, materials selection is a very important issue. Preliminary evaluation of the material's suitability represents therefore a valuable strategy to ensure a secure and reliable operation of the facilities. In geothermal applications, the use of high-alloyed materials such as superaustenitic stainless steels, duplex stainless steels, and nickel-based alloys has been considered as a good alternative because of their remarkable corrosion resistance and appropriate mechanical properties. Nevertheless, the corrosion behavior of those metallic materials in geothermal fluids at service conditions has not been determined in many cases. In this work, laboratory tests including electrochemical investigations and exposure tests at 100 degrees C and 150 degrees C (1,500 kPa) showed the limits of suitability concerning localized corrosion of three different, corrosion-resistant alloys in the highly saline fluid of the North German Basin. T2 - EPRI International Conference on Corrosion in Power Plants CY - San Diego, CA, USA DA - 12.10.2015 KW - Geothermal KW - Corrosion KW - Crevice corrosion KW - Suitability PY - 2015 DO - https://doi.org/10.5006/1.3676631 SP - paper 6 AN - OPUS4-34754 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Alves, H. A1 - Behrens, R. A1 - Kurumlu, D. A1 - Bäßler, Ralph T1 - High performance alloys to mitigate corrosion in the energy industry - a contribution to a clean environment N2 - In order to evaluate materials for components in geothermal brines with high salt content a range of corrosion resistant materials has been selected for corrosion testing, comprising the materials alloy 31, 625, 59, 2120 and titanium Ti Gr. 2. Testing was done in an artificial brine simulating the natural conditions of the North German Basin at the Groß Schönebeck location with high salt content (165 g/l Cl-) and a test temperature of 150 °C. Pitting corrosion had occurred on alloys 31 and 625 after potentiodynamic polarization. The results obtained on the alloys 59, 2120 and Ti Gr.2 indicate that these materials are offering sufficient resistance to the various forms of corrosive attack as they might occur in geothermal saline services of this kind. For the most aggressive service conditions as they may occur in flue gas desulfurization, waste incineration, other aspects of environmental engineering and beyond, a new nickel alloy with 21 % Cr and 19 % Mo has been developed recently. The new alloy 2120 is the first Ni-Cr-Mo alloy to contain nitrogen as an alloying constituent. Together with the chromium and the increased molybdenum content the alloying with nitrogen results in a pitting resistance equivalent number (PREN) of about 86 and a corresponding high resistance to pitting and crevice corrosion, surpassing the nickel-chromium-molybdenum alloys being commonly in use so far. The alloy is easily manufactured into the various shapes which are needed in flue gas desulfurization, waste incineration and other industrial equipment. Depending on the wall thickness welding can be done using a matching filler or without filler metal. T2 - EUROCORR 2013 - The European corrosion congress CY - Estoril, Portugal DA - 01.09.2013 KW - Alloy 31 (EN 1.4562, UNS N08031) KW - Alloy 31 plus KW - Alloy 625 (EN 2.4856, UNS N06625) KW - Alloy C-276 (EN 2.4819, UNS N10276) KW - Alloy 59 (EN 2.4605, UNS N06059) KW - Alloy 2120 (EN 2.4700, UNS N06058) KW - Titanium Ti Gr. 2 (DIN 3.7035, UNS R50400) KW - Geothermal brines KW - Flue gas desulfurization KW - Pitting corrosion KW - Crevice corrosion PY - 2013 SN - 978-989-8601-31-5 SP - 1 EP - 13 (Paper 1238) AN - OPUS4-29478 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Landsberger, Petra A1 - Boenke, Viola A1 - Gorbushina, Anna A1 - Rodenacker, K. A1 - Pierce, B.F. A1 - Kratz, K. A1 - Lendlein, A. T1 - Bacterial attachment on poly[acrylonitrile-co-(2-methyl-2-propene-1-sulfonic acid)] surfaces N2 - The influence of material properties on bacterial attachment to surfaces needs to be understood when applying polymer-based biomaterials. Positively charged materials can kill adhered bacteria when the charge density is sufficiently high but such materials initially increase the adherence of some bacteria such as Escherichia coli. On the other hand, negatively charged materials have been shown to inhibit initial bacterial adhesion, but this effect has only been demonstrated in relatively few biomaterial classes and needs to be evaluated using additional systems. Gradients in surface charge can impact bacterial adhesion and this was tested in our experimental setup. Moreover, the evaluation of bacterial adhesion to biomaterials is required to assess their potential for biological applications. Here, we studied the bacterial adhesion of E. coli and Bacillus subtilis on the surfaces of acrylonitrile-based copolymer samples with different amounts of 2-methyl-2-propene-1-sulfonic acid sodium salt (NaMAS) comonomer. The content related to NaMAS based repeating units nNaMAS varied in the range from 0.9 to 1.5 mol%. We found a reduced colonized area of E. coli for NaMAS containing copolymers in comparison to pure PAN materials, whereby the bacterial colonization was similar for copolymers with different nNaMAS amounts. A different adhesion behavior was obtained for the second tested organism B. subtilis, where the implementation of negative charges into PAN did not change the overall adhesion pattern. Furthermore, it was observed that B. subtilis adhesion was significantly increased on copolymer samples that exhibited a more irregular surface roughness. T2 - MRS Spring meeting 2013 CY - San Francisco, CA, USA DA - 01.04.2013 KW - Biomaterial KW - Biological KW - Polymer PY - 2013 DO - https://doi.org/10.1557/opl.2013.832 VL - 1569 IS - MRSS13-1569-NN15-13.R1 SP - 1 EP - 6 AN - OPUS4-30161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Sarmiento Klapper, Helmuth A1 - Feigl, Michael A1 - Hilker, Nico T1 - Corrosion resistance of high-alloyed and alternative materials in an artificial geothermal water N2 - Many technologies have been developed to take advantage of geothermal energy, which became a feasible energy source to replace fossil fuel supply. Nevertheless, service conditions in geothermal facilities are due to the chemical composition of hydrothermal fluids and involved high temperatures, in many cases, extreme in terms of corrosion. Therefore, materials selection based on preliminary material qualification is essential to guarantee a secure and reliable operation of the facilities. This contribution deals with the evaluation of the corrosion behavior of two high-alloyed metallic materials and α-Al2O3 in an artificial geothermal fluid simulating the conditions in the Northern German Basin, a location with high geothermal potential. The suitability of the super austenitic stainless steel UNS N08031 and the nickel base alloy UNS N06059 in this geothermal fluid obtained by electrochemical measurements and exposure tests is addressed. As an alternative to the suitable but costly UNS N06059 that showed excellent corrosion resistance against pitting corrosion, ceramic made of α-Al2O3 represents an interesting possibility for selected components to be used in the construction of geothermal facilities T2 - Corrosion 2014 CY - San Antonio, TX, USA DA - 09.03.2014 KW - Localized corrosion KW - Stainless steel KW - Ni-based alloy KW - Ceramic KW - Geothermal energy PY - 2014 SP - Paper 3826, 1 EP - 8 AN - OPUS4-30632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Boduch, Alicja A1 - Sobetzki, Joana T1 - Corrosion resistance of high-alloyed materials in flowing artificial geothermal water N2 - Since geothermal wells are a feasible energy source to replace fossil fuel supply, many technologies have been developed to take advantage of geothermal energy. Nevertheless, service conditions in geothermal facilities are due to the chemical composition of hydrothermal waters and temperatures, in many cases, extreme in terms of corrosion. Therefore, materials selection based on preliminary material qualification is essential to guarantee a secure and reliable operation of the facilities. This contribution deals with the evaluation of the corrosion behavior of different steels in flowing low saline, slightly alkaline, artificial geothermal water simulating the conditions in the Molasse-Basin, a location with geothermal potential in Germany. Test results for steels UNS S31603 and UNS S31803 exposed to this geothermal water obtained by electrochemical measurements and exposure tests are presented. Results obtained in static and flowing water condition show good performance of both alloys with a possible onset of localized corrosion at UNS S31603 in static conditions. T2 - Corrosion 2014 CY - San Antonio, TX, USA DA - 09.03.2014 KW - Localized corrosion KW - Steel KW - Duplex steel KW - Flow KW - Sulfide KW - Geothermal energy PY - 2014 SP - Paper 3825, 1 EP - 8 AN - OPUS4-30631 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Yevtushenko, Oleksandra A1 - Hattendorf, H. T1 - Electrochemical characterization of high alloyed materials in molten salts for solar energy applications N2 - Within the last years the use of feasible alternative energy sources has risen and is going to replace fossil resources more and more. Nevertheless, service conditions in solar facilities are due to the chemical composition of heat transmission media and temperatures, in many cases, extreme in terms of corrosion. Since the construction of power plants shall be economical with maximum life service, materials selection based on preliminary material qualification is essential to guarantee a secure and reliable operation of those facilities. The materials selection depends on the operation temperature of a power plant on the chemical composition of the transmission fluid used. In high corrosive environments Ni-based alloys are often used as an all-round solution for the construction of corrosion resistant parts, because of their good corrosion properties. However, there might be limits for their use regarding their corrosion behavior, with which this contribution deals. Experiences from the electrochemical characterization of materials in aqueous solutions are transferred to molten salts, providing a good addition to common exposure tests at temperatures from 450 0C to 600 0C. By means of electrochemical measurements and exposure tests the suitability of high alloyed materials in molten nitrate salt (60 % NaNO3/40 % KNO3) can be characterized. The method was verified on different Ni-based alloys (UNS N08810, UNS N06600) and Titanium (UNS R50250). T2 - NACE International Corrosion Conference 2015 CY - Dallas, TX, USA DA - 15.03.2015 KW - Localized corrosion KW - Nickel based alloys KW - Solar energy KW - Renewables KW - Electrochemical characterization KW - UNS N08810 KW - UNS N06600 KW - UNS R50250 PY - 2015 SP - paper 5659, S. 1 EP - 9 AN - OPUS4-34748 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yevtushenko, Oleksandra A1 - Bäßler, Ralph A1 - Bettge, Dirk T1 - Corrosion susceptibility of steels under transport and injection exploitation conditions possible in CCS process chain N2 - Once sequestrated, C02 will be transported and injected in its gaseous, liquid or supercritical state. The presence of impurities significantly influences the corrosion behavior of pipeline steels even with small concentrations of water below its Saturation limit. T2 - EUROCORR 2014 - European corrosion congress CY - Pisa, Italy DA - 08.09.2014 KW - Corrosion KW - Stainless steel KW - CCS KW - COORAL PY - 2014 SN - 978-3-89746-159-8 SP - 1 AN - OPUS4-32745 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sobetzki, Joana A1 - Bäßler, Ralph A1 - Boduch, Alicja T1 - The effects of sulfide and flow rate on corrosion behavior of duplex steel 1.4462 in the artificial molasse basin fluid N2 - Within the last years the use of geothermal energy as feasible energy source has risen and is going to replace fossil fuel supply more and more. Nevertheless, Service conditions in geothermal facilities are due to the Chemical composition of hydrothermal fluids and temperatures, in many cases, extreme in terms of corrosion. Since the construction of geothermal power plants shall be economical with maximum life Service, materials selection based on preliminary material qualification is essential to guarantee a secure and reliable Operation of those facilities. T2 - EUROCORR 2014 - European corrosion congress CY - Pisa, Italy DA - 08.09.2014 KW - Locallized corrosion KW - Duplex steel KW - Geothermal energy PY - 2014 SN - 978-3-89746-159-8 SP - 1 AN - OPUS4-32744 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Sarmiento Klapper, Helmuth A1 - Feigl, Michael A1 - Hilker, Nico T1 - Suitability of high-alloyed or alternative non-metallic materials in high saline artificial geothermal waters N2 - Many technologies have been developed to take advantage of geothermal energy, which became a feasible energy source to replace fossil fliel supply. Nevertheless, Service conditions in geothermal facilities are due to the Chemical composition of hydrothermal fluids and involved high temperatures, in many cases, extreme in terms of corrosion. Therefore, materials selection based on preliminary material qualification is essential to guarantee a secure and reliable Operation ofthe facilities. This contribution deals with the evaluation of the corrosion behavior of two high-alloyed metallic materials and a-A1203 in an artificial geothermal fluid simulating the conditions in the Northern German Basin, a location with high geothermal potential. The suitability of the super austenitic stainless Steel, alloy 31, and the nickel base alloy 59 in this geothermal fluid obtained by electrochemical measurements and exposure tests is addressed. As an alternative to the suitable but costly alloy 59 that showed excelient corrosion resistance against pitting corrosion, ceramic made of a-A1203 represents an interesting possibility for selected components to be used in the construction of geothermal facilities. T2 - Corrosion-2014 - XIIth International conference "Problems of corrosion and corrosion protection of structural materials" CY - Lviv, Ukraine DA - 11.06.2014 KW - Localized corrosion KW - Steel KW - Ni-alloy KW - Ceramic KW - Geothermal energy PY - 2014 SP - 18 EP - 22 AN - OPUS4-32743 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Schmidt, C. A1 - Alves, H. T1 - Recent experiences on suitability of titanium and high alloyed materials in acids at 200°C N2 - In the literature there are not much data available to describe the corrosion behavior of titanium, nickel alloys and special stainless steels in acids at high temperature, in particular above the boiling point. Therefore, a laboratory testing program was performed with two titanium alloys (UNS R50400 and UNS R53400) to obtain corrosion data in formic acid, acetic acid, phosphoric acid, polyphosphoric acid, p-toluene sulfonic acid and lactic acid at 200 °C. Results were compared to previously published ones obtained on UNS N08031, UNS N06059 and UNS N10665. From the results it can be concluded that titanium does not always show better corrosion resistance than Ni-based alloys. UNS N06059 was the best choice for formic and acetic acids at temperatures of 200 °C. Both Ti-alloys are resistant in acetic acid. Some slight differences were observed for formic acid, where UNS R50400 is only resistant up to a 20 % solution and UNS R53400 in concentrated acid too. The phosphoric acid is extremely corrosive and none of the investigated materials was resistant. In the diluted acid (5 %) only UNS R53400 is resistant, whereas in 1 % solution all investigated materials performed satisfactory. UNS N10665 and UNS N06059 showed the best behavior in polyphosphoric acid. In 30 % concentrated p-toluene sulfonic acid at 200 °C all alloys tested were unsuitable. In very diluted acid (0.1 %) both Ti-alloys and the other three alloys behaved well. In lactic acid at 180 °C increased corrosion underneath deposits was detected; the best performance was observed for UNS N06059 and UNS R50400. T2 - NACE International Corrosion Conference 2015 CY - Dallas, TX, USA DA - 15.03.2015 KW - Titanium grade 2 (UNS 50400) KW - grade 12 (UNS 53400) KW - alloy 59 (UNS N06059) KW - alloy 31 (UNS N08031) KW - alloy B-2 (UNS N10665) KW - Inorganic acids KW - Organic acids KW - Corrosion PY - 2015 SP - paper 5658, S. 1 EP - 13 AN - OPUS4-34749 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Osterloh, Kurt A1 - Wrobel, Norma ED - Aschenbruck, N. ED - Martini, P. ED - Meier, M. ED - Tölle, J. T1 - Safety and security, dealing with risks N2 - Reducing risks and confining them to an acceptable level can be regarded as an essential commitment of technical applications for safety purposes and the public security measures. Rating the efficiency of such measures requires an assessment of the risk that is supposed to be reduced. However, approaching this subject means to face a plethora of existing literature and an ongoing discussion if and how this can be achieved. On one hand, it remains a rather uncertain estimate particularly if it comes to rare interrupting events. On the other hand, making a decision responsibly requires a certain rational base. Several approaches exist for assessing risks, from verbal to quantitative, depending on the individual case. The frequently quoted Delphi technique represents the verbal one, others such as the Bayesian statistics a quantitative one or the consequence/probability matrix in-between. A problem remains with understanding probability. Even if an event is highly unlikely it may happen right now. T2 - Future Security 2012 - 7th Security research conference CCIS CY - Bonn, Germany DA - 04.09.2012 KW - Risk definition KW - Risk assessment KW - Public safety and security PY - 2012 UR - http://link.springer.com/chapter/10.1007/978-3-642-33161-9_13 SN - 978-3-642-33160-2 SN - 978-3-642-33161-9 DO - https://doi.org/10.1007/978-3-642-33161-9 SN - 1865-0929 SN - 1865-0937 VL - 318 SP - 77 EP - 80 PB - Springer AN - OPUS4-27550 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Martin A1 - Ballheimer, Viktor A1 - Sterthaus, Jens A1 - Schubert, Sven A1 - Eisenacher, Germar A1 - Wille, Frank T1 - Material characterization and modeling within safety analysis of packages for transport of radioactive material N2 - In mechanical design safety assessment ofpackages for the transport of radioactive material the International Atomic Energy Agency (IAEA) regulations [1,2] require the use of one of four methods of demonstration of compliance with regulations: tests with prototypes, reference to previous satisfactory demonstrations, tests with scaled models as well as calculation or reasoned argument. In all cases characterization of material behavior is necessary. The need for material characterization can be split into three groups: characterization for material modeling in the design and verification process, determination of assessment criteria and inspections during manufacturing. The paper deals primarily with material characterization for the material modeling in the design phase and authorities approval process. Main package components are discussed: cask body and lids, screws, trunnions, impact limiter and basket(structure holding the content in specified position). Depending on the material used for these components this paper Shows exemplary a possible set of material investigations in order to allow modeling in design and assessment during the approval process. T2 - ASME 2012 Pressure vessels & piping division conference CY - Toronto, Ontario, Canada DA - 15.07.2012 PY - 2012 SP - PVP2012-78297, 1-6 PB - American Society of Mechanical Engineers CY - New York AN - OPUS4-26271 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Priebe, Nsesheye Susan A1 - Kühne, Hans-Carsten ED - Alexander, M. G. ED - Beushausen, H.-D. ED - Dehn, F. ED - Moyo, P. T1 - Robustness improvement of fresh concrete and mortar performance for challenging casting environments with focus on sub-Saharan Africa N2 - For various concrete applications, the early properties are a major specification, determining the functioning, the mechanical properties, and the durability of structures. The rheological properties of cementitious systems are depending on the water-cement interaction as well as on interactions of chemical admixtures with the cement hydration. The cement hydration, however, is strongly affected by the environmental boundary conditions, such as the climate or the available equipment for the proportioning and dispersion of concrete. This paper presents strategies for the robustness improvement of fresh properties of cementitious systems for challenging and particularly warm climate conditions. After explaining the basic mechanisms affecting the workability, practical conclusions are drawn with special attention on the circumstances of sub-Saharan Africa, where the climatic conditions are difficult and the casting technology is often limited. Solutions are suggested, how despite the disadvantageous circumstances, highly elaborate engineered concrete and mortar can be applied safely and with consistent quality. T2 - 3rd International conference on concrete repair, rehabilitation and retrofitting III CY - Cape Town, South Africa DA - 03.09.2012 PY - 2012 SN - 978-0-415-89952-9 N1 - Geburtsname von Priebe, Nsesheye Susan: Msinjili, N. S. - Birth name of Priebe, Nsesheye Susan: Msinjili, N. S. IS - Theme 4 SP - 1324 EP - 1329 PB - CRC Press CY - London, UK AN - OPUS4-26503 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Cunnigham, P. R. A1 - Shaba, A. F. A1 - Olonade, K. A. A1 - Ndawula, J. A1 - Tawiah, A. T. A1 - Marangu, J. M. A1 - Tlhatlha, Pheladi A1 - Obeng, E. ED - Banhia, N. T1 - Informal Sector Inclusion in Sustainable Concrete Construction in Africa N2 - Concrete used as a construction material is inevitable in Africa’s rapid urban growth, despite its significant contribution to carbon emissions. Hence, best practice concrete with reduced Portland cement clinker needs to be applied. The highly informal nature ofAfrica’s construction sector could impede the implementation of sustainable concrete construction. Although urgent need for economisation unintentionally often leads informal actors to operate according to circularity principles, the sector lacks awareness of climate challenges and incentives for adopting climate-friendly materials and technologies. In addition, the informal sector is prone to fraudulent adulterated materials and components causing challenges for safe and durable construction. The authors elaborate on the crucial role of the informal sector in driving sustainable construction forward, despite the lack of policies and disinterest from regulatory bodies. Solutions through education, communication, and quality control are proposed and discussed. T2 - 77th RILEM Annual Week and the 1st Interdisciplinary Symposium on Smart & Sustainable Infrastructures (ISSSI 2023) CY - Vancouver, Canada DA - 04.09.2023 KW - Cement testing KW - Hydration KW - Economic development KW - Informal sector KW - Cement chemistry PY - 2024 SN - 978-3-031-53391-4 DO - https://doi.org/10.1007/978-3-031-53389-1_47 VL - 48 SP - 506 EP - 520 PB - Springer Nature Switzerland AG CY - Schweiz AN - OPUS4-61586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Werner, Steve A1 - Schmidt, Wolfram A1 - Pirskawetz, Stephan A1 - Rogge, Andreas ED - Khayat, Kamal Henry T1 - Fire spalling of self-compacting concrete mixtures with different limestone powder contents N2 - Self-compacting concrete typically contains a higher content of powder materials than normal concrete. Furthermore it is assumed that the use of superplasticizers yields a more homogenous microstructure in the hardened paste. Both aspects generate a very dense microstructure, which can be assumed to cause material behaviour that differs from than normal concrete when it is exposed to elevated temperatures. However, the paste volumes in SCC can vary significantly based on the mixture composition. At a low paste volumes SCC can be very similar to normal concrete at hardened state while it can vary greatly at higher paste volumes. Since the high temperature behaviour of concrete is strongly affected by the different physical behaviour of the paste and the aggregates, it is likely that the high temperature behaviour is consequently strongly affected by the ratio of these mixture components. In the present study different SCC mixtures were observed with similar mechanical properties, but with significantly differing paste to aggregate ratios. Based on observations of the heat evolution at the fire exposed surface and at different depths inside the specimens as well as based on photogrammetric observations of the spalled dimensions, the results indicate that with increasing paste volumes the heat conductivity is reduced and as a result concrete with higher paste to aggregate ratios shows less spalling. T2 - 8th RILEM Symposium on Self-Compacting Concrete CY - Washington, USA DA - 15.05.2016 KW - Spalling KW - High temperature behaviour KW - Fire exposure KW - Mixture composition KW - Photogrammetry PY - 2016 SN - 978-2-35158-157-5 SP - 353 EP - 363 PB - RILEM Publications S.A.R.L. CY - Paris, France AN - OPUS4-36873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Olonade, K. A. A1 - Mbugua, R. N. A1 - Lenz, F. J. A1 - Tchetgnia Ngassam, I. T1 - Bio-Based Rheology Modifiers for High Performance Concrete – Possible Modes of Actions and Case Study for Cassava Starch in West Africa N2 - Polymers that help tailoring rheological properties during the casting process have become inevitable constituents for all kinds of high-performance concrete technologies. Due to lacking industries, these typically crude-oil based admixtures are not readily available in many parts of the world, which limits the implementation of more sustainable high-performance construction technologies in these regions. Alternative polymers, which often demand for less processing, can be derived from local plant-based resources. The paper provides experimental data of flow tests of cement pastes with polysaccharides from Triumfetta pendrata A. Rich, acacia gum and cassava without and in the presence of polycarboxylate ether superplasticizer. The flow tests are amended by observations of the zeta potentials and the hydrodynamic diameters in the presence of and without calcium ions in the dispersion medium. The results show that in the presence of and without calcium ions all polysaccharides provide negative zeta potentials, yet, they affect flowability and thixotropy in different ways. Cassava starch, acacia gum, and the gum of Triumfetta pendrata A. Rich qualified well for robustness improvement, strong stiffening, and additive manufacturing, respectively. The reason for the different effects can be found in their average sizes and size distribution. Due to the promising results, a flow chart for local value chains is derived on the example of yet unused cassava wastes, which can be converted in parallel. T2 - 3rd International Conference on the Application of Superabsorbent Polymers CY - Skukuza, South Africa KW - Admixtures KW - Polysaccharides KW - Rheology KW - Thixotropy KW - Concrete PY - 2020 SN - 978-3-030-33341-6 SN - 978-3-030-33342-3 DO - https://doi.org/10.1007/978-3-030-33342-3_17 SP - 158 EP - 166 PB - Springer AN - OPUS4-58404 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Werner A1 - Wöhlecke, Andreas ED - Ziegler, M. ED - Bräu, G. ED - Heerten, G. ED - Laackmann, K. T1 - The performance of geocomposite drains in the long run N2 - Like all plastic products, geocomposite drains (GCD) are susceptible to creep and creep rupture. The GCD is slowly and continuously deformed under long lasting shear and pressure forces. The thickness is reduced and thereby the water flow capacity. If the in-plane deformation reaches a critical value in the course of time, shear failure might occur. Likewise, if the thickness reaches a critical value the structure of the drain core might collapse. These effects are shown using data provided by the manufacturers of four different GCD. Long-term water flow capacity and the acceptable limits of shear stress and normal stress (pressure) with respect to shear rupture and drain core stability as well as the lifetime with respect to these failure modes are determined using standard test methods. The design of long lasting geotechnical structures has to take into account these characteristics of the long-tem performance of GCD. T2 - 10th International conference on geosynthetics CY - Berlin, Germany DA - 21.09.2014 KW - Geocomposite drains KW - Creep KW - Creep rupture KW - Long-term water flow capacity KW - Long-term shear strength KW - Drain core stability PY - 2014 SN - 978-3-9813953-9-6 SP - 1 EP - 7 AN - OPUS4-31574 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Priebe, Nsesheye Susan A1 - Schmidt, Wolfram A1 - Gluth, Gregor A1 - Florea, M.V.A. A1 - Kumaran, G.S. A1 - Akindahunsi, A. A. A1 - Uzoegbo, H.C. A1 - Oslakovic, I.S. ED - Alexander, M. G. ED - Beushausen, H.-D. ED - Dehn, F. ED - Moyo, P. T1 - Concrete knowledge improvement in sub-Saharan Africa N2 - The building situation in Africa is overwhelmed with high-priced materials and lack of adequate concrete technology, which provides a challenge in the concrete industry. Worldwide, cement and concrete experts are at the cutting-edge to sustainable, green and healthy but nonetheless high-performance concrete, which is more sustainable and safer than traditional methods of construction with clay and wood. Since concrete in Africa is rather a new construction material, this sustainability experience can offer the continent a unique opportunity to begin a constantly growing building sector with the newest state-of-the-art technology. This can be achieved without subordinating to existing standards by establishing a sustainable “African concrete technology”. The major challenge for most sub-Saharan countries is the deficiency of experts, which would be required to establish such state-of-the-art technology. Based on the examples of two African-European scientific networks—SPIN and LightSHIP—this paper presents possible solution strategies for the establishment of a scientific cooperation between Europe and Africa, with links to policy making bodies that can help accelerate the progress of cement and concrete industries in Africa. T2 - 3rd International conference on concrete repair, rehabilitation and retrofitting III CY - Cape Town, South Africa DA - 03.09.2012 KW - Education KW - Research sub-Sahara KW - Africa KW - Cement KW - Concrete PY - 2012 SN - 978-0-415-89952-9 N1 - Geburtsname von Priebe, Nsesheye Susan: Msinjili, N. S. - Birth name of Priebe, Nsesheye Susan: Msinjili, N. S. IS - Theme 5 SP - 1459 EP - 1465 PB - CRC Press CY - London, UK AN - OPUS4-26508 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miccoli, Lorenzo A1 - Müller, U. A1 - Silva, B. A1 - Da Porto, F. A1 - Hracov, S. A1 - Pospisil, S. A1 - Adami, C.-E. A1 - Vintzileou, E. A1 - Vasconcelos, G. A1 - Poletti, E. ED - Jasienko, J. T1 - Overview of different strengthening techniques applied on walls used in historical structures N2 - Different types of vertical elements, such as masonry, massive walls and timber frame elements, exhibit a different response exposed to the same loading scenario, in particular when it concerns dynamic loading. It is therefore paramount to investigate the principal response of different types of construction with different materials under a variety of loading scenarios. From there, the design of strengthening techniques against earthquakes can be performed. This paper presents the results from experiments, where various retrofitting techniques were tested. The goals were to define and improve laboratory procedures for evaluating the intervention technologies and specifications for laboratory specimens. From this base tests to characterise the experimental behaviour of original and strengthened masonry walls were performed, in order to obtain information on the system performance and the main constitutive laws relevant for modelling. The test campaigns were focused on static tests as well as cyclic tests of unreinforced and reinforced vertical building elements. The study is part of our work in the framework of the ongoing project NIKER funded by the European Commission dealing with improving immovable Cultural Heritage assets against the risk of earthquakes. T2 - SAHC 2012 - 8th International conference on structural analysis of historical constructions CY - Wroclaw, Poland DA - 15.10.2012 KW - Stone masonry KW - Brick masonry KW - Earthen materials KW - Half timbered walls KW - Grouting PY - 2012 SN - 978-83-7125-216-7 SN - 0860-2395 VL - 3 SP - 2870 EP - 2878 PB - DWE CY - Wroclaw, Poland AN - OPUS4-27275 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vintzileou, E. A1 - Valluzzi, M.R. A1 - Mazzon, N. A1 - Posipsil, S. A1 - Miccoli, Lorenzo ED - Jasienko, J. T1 - Systemic improvement of overall seismic response N2 - Subassemblies and building models at reduced scale are tested on shaking table facilities. This experimental program is part of the project NIKER and constitutes the Work Package 7 (WP7): “Systemic improvement of overall seismic response”. The purpose of this WP is to define global intervention strategies through shaking table tests on both substructures and entire structures before and after intervention in order to check the performance of single elements and to characterize the seismic behaviour of whole buildings. The obtained results will also allow data for FE and analytical modelling to be obtained for both single elements and whole structures. The design and the testing protocol of both subassemblies and building models were based on the results obtained from the experimental campaigns carried out on individual vertical members (quasi-static tests), on horizontal elements (e.g. floors and roofs) and on connections between bearing elements, all these performed within the same project. The experiments summarized in this paper proved the efficiency of the investigated intervention techniques and provided fundamental data to calibrate analytical models, developed within the same project, in order to describe the seismic behaviour of historic structures both in unstrengthened and strengthened conditions. This paper provides a brief overview of the whole dynamic experimental campaign and introduces some key experimental results. T2 - SAHC 2012 - 8th International conference on structural analysis of historical constructions CY - Wroclaw, Poland DA - 15.10.2012 KW - Historic structures KW - Shaking table tests KW - Subassemblies KW - Scaled models PY - 2012 SN - 978-83-7125-216-7 SN - 0860-2395 VL - 3 SP - 2897 EP - 2905 PB - DWE CY - Wroclaw, Poland AN - OPUS4-27274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Paganoni, S. A1 - D'Ayala, D. A1 - Miccoli, Lorenzo A1 - Hracov, S. A1 - Urushadze, S. A1 - Wünsche, M. A1 - Adami, C.-E. A1 - Vintzileou, E. A1 - Moreira, S. A1 - Oliveira, D.V. A1 - James, P. A1 - Cóias e Silva, V. ED - Jasienko, J. T1 - Connections and dissipative systems with early warning N2 - The global response of historic buildings is determined by the behaviour of the single structural elements as well as by their mutual connections. Consequently, in the last decades a number of technical solutions for the improvement of structural connections have been developed in response to the increasing demand in the field of the seismic protection of heritage assets. At the same time, the experimental assessment of structural strengthening techniques is a well established practice both in the scientific community and among commercial producers. It is therefore surprising how testing of connections is rarely performed and very few codes of practice deal with it. Additionally, the few existing experimental procedures for testing connections are neither standardised nor easily accessible to end users. Within the work frame of the EU-funded NIKER project, Work Package 6 aims to address such technical gap through the development of procedures specific to the strengthening of structural connections of historic buildings. T2 - SAHC 2012 - 8th International conference on structural analysis of historical constructions CY - Wroclaw, Poland DA - 15.10.2012 KW - Seismic strengthening KW - Structural connections KW - Heritage buildings PY - 2012 SN - 978-83-7125-216-7 SN - 0860-2395 VL - 3 SP - 2888 EP - 2896 PB - DWE CY - Wroclaw, Poland AN - OPUS4-27276 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -