TY - GEN ED - Bonse, Jörn ED - Spaltmann, Dirk T1 - Laser-induced periodic surface nano- and microstructures for tribological applications N2 - This book is a reprint collection of articles from the Special Issue published online in the open access journal Lubricants. KW - Laser-induced periodic surface structures (LIPSS) KW - Friction KW - Wear KW - Applications PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-516611 UR - https://www.mdpi.com/books/pdfview/book/3130 SN - 978-3-03943-523-4 SN - 978-3-03943-524-1 SP - 1 EP - 180 PB - MDPI CY - Basel AN - OPUS4-51661 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cubero, A. A1 - Martínez, E. A1 - Angurel, L.A. A1 - de la Fuente, G.F. A1 - Navarro, R. A1 - Legall, Herbert A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Surface superconductivity changes of niobium sheets by femtosecond laser-induced periodic nanostructures N2 - Irradiation with ultra-short (femtosecond) laser beams enables the generation of sub-wavelength laser-induced periodic surface structures (LIPSS) over large areas with controlled spatial periodicity, orientation, and depths affecting only a material layer on the sub-micrometer scale. This study reports on how fs-laser irradiation of commercially available Nb foil samples affects their superconducting behavior. DC magnetization and AC susceptibility measurements at cryogenic temperatures and with magnetic fields of different amplitude and orientation are thus analyzed and reported. This study pays special attention to the surface superconducting layer that persists above the upper critical magnetic field strength Hc2, and disappears at a higher nucleation field strength Hc3. Characteristic changes were distinguished between the surface properties of the laser-irradiated samples, as compared to the corresponding reference samples (non-irradiated). Clear correlations have been observed between the surface nanostructures and the nucleation field Hc3, which depends on the relative orientation of the magnetic field and the surface patterns developed by the laser irradiation. KW - Niobium KW - Surface superconductivity KW - Laser-induced periodic surface structures (LIPSS) KW - Nanostructures PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518462 DO - https://doi.org/10.3390/nano10122525 SN - 2079-4991 VL - 10(12) IS - Special issue "Laser-generated periodic nanostructures" SP - 1 EP - 16 PB - MDPI CY - Basel AN - OPUS4-51846 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lüders, C. A1 - Kalinka, Gerhard A1 - Li, Wei A1 - Sinapius, M. A1 - Wille, T. T1 - Experimental and numerical multiscale approach to thermally cycled FRP N2 - Due to the different thermal expansion of the constituent materials, cyclic thermal loading of FRP induces alternating stresses in the material at two scales: at the micro scale (level of fibre–matrix-interaction) and at the macro scale (level of the multidirectional laminate). Especially the micro scale effect is not comprehensively investigated yet. Additionally, computational investigations mostly neglect this effect due to the homogenous modelling of the composite material. As this effect is assumed to significantly contribute to the fatigue of FRP at thermal loads, the present paper suggests an experimental and numerical multiscale approach including Experiments at the different involved material scales to separately observe the effects acting at these scales. The approach also includes numerical modelling for each scale to complement the knowledge gained from the Experiments and to create a basis for the consideration of the micro effect even in macroscopic fatigue models treating homogeneous modelled composites. The main focus of the contribution is to bring the overall Approach up for discussion, rather than to present the multiscale modelling details. KW - Fatigue KW - Thermal cycling KW - Fibre reinforced plastic KW - Cryogenic KW - Carbon Fibre KW - Epoxy Resin PY - 2020 DO - https://doi.org/10.1016/j.compstruct.2020.112303 SN - 0263-8223 VL - 244 SP - 112303 PB - Elsevier Ltd. CY - Niederlande AN - OPUS4-50844 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Cheng-Chieh A1 - Weisbrich, S. A1 - Burger, M. A1 - Neitzel, F. ED - Zemčík, R. T1 - A four-point bending test apparatus for measurement- and model-based structural analysis N2 - By means of a small-scale truss bridge, the ability of the Measurement- and Model-based Structural Analysis to detect and localise damage was examined in. Although there was no noteworthy difficulty in detecting damage, it turned out that damage localisation responds sensitively to systematic influences, i.e. non-modelled properties of the mechanical model. Therefore, another experiment is being conducted to re-examine the Measurement- and Model-based Structural Analysis. For this purpose, the bending test is carried out as it has been already theoretically respectively numerically discussed in. In this attempt, the systematic influences such as residual stress are kept as low as possible. T2 - 36th Danubia Adria Symposium on Advances in Experimental Mechanics CY - Pilsen, Czech Republic DA - 24.09.2019 KW - Damage detection KW - Adjustment calculation KW - Finite element method KW - Integrated analysis PY - 2020 UR - http://www.sciencedirect.com/science/article/pii/S2214785320326432 DO - https://doi.org/10.1016/j.matpr.2020.04.028 SN - 2214-7853 VL - 32 IS - 2 SP - 156 EP - 161 PB - Elsevier Ltd. AN - OPUS4-51551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Acosta-Zepeda, C. A1 - Saavedra, S. A1 - Bonse, Jörn A1 - Haro-Poniatowski, E. T1 - Modelling of single UV nanosecond pulsed laser surface modifications of silicon N2 - Irradiation with a single spatially Gaussian-shaped nanosecond laser pulse in the melting regime can result in a characteristic annular change in the surface morphology of crystalline silicon. This has been verified experimentally in a variety of situations, where dimple-shaped surface topographies are produced. In a recent work we have investigated the induced changes in the surface topography upon exposure to wavelengths in the visible and near infrared spectral region. Irradiation in the UV requires a more detailed analysis due to the enhanced absorption of the material. In the present analysis, we determine under which conditions our previous model can be used and the corresponding results are presented. KW - Laser KW - Silicon KW - Surface modification PY - 2020 DO - https://doi.org/10.1088/1555-6611/ab9b2c SN - 1555-6611 SN - 1054-660X VL - 30 IS - 8 SP - 086003-1 EP - 086003-4 PB - IOP Publishing / Astro Ltd CY - Bristol, United Kingdom AN - OPUS4-51022 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR ED - Pfeffer, M. ED - Bonse, Jörn ED - Lasagni, A. F. T1 - Topical issue: Laser micro- and nano-material processing - Part 1 N2 - This special issue of Advanced Optical Technologies (AOT) is dedicated to the field of laser-based micro- and nanostructuring methods. KW - Laser processing KW - Microstructures KW - Nanostructures KW - Applications PY - 2020 UR - https://www.degruyter.com/view/journals/aot/9/1-2/aot.9.issue-1-2.xml SN - 2193-8576 SN - 2193-8584 VL - 9 IS - 1-2 SP - 7 EP - 110 PB - De Gruyter CY - Berlin AN - OPUS4-50798 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mezera, Marek T1 - Bacterial adhesion on femtosecond laser-induced periodic surface structures N2 - Biofilm formation in industrial or medical settings is usually unwanted and leads to serious health problems and high costs. Inhibition of initial bacterial adhesion prevents biofilm formation and is, therefore, a major mechanism of antimicrobial action of surfaces. Surface topography largely influences the interaction between bacteria and surfaces which makes topography an ideal base for antifouling strategies and eco-friendly alternatives to chemical surface modifications. Femtosecond laser-processing was used to fabricate sub-micrometric surface structures on silicon and stainless steel for the development of antifouling topographies on technical materials. T2 - Future Tech Week 2020 CY - Online meeting DA - 21.09.2020 KW - Laser-induced periodic surface structures (LIPSS) KW - Bacterial adhesion KW - Biofilm growth KW - Structural color KW - Femtosecond laser processing PY - 2020 UR - http://futuretechweek.fetfx.eu/wp-content/uploads/gravity_forms/2-5432af7ecff9e0243d7383ab3f931ed3/2020/09/BioCombs4Nanofibers_Poster-for-Future_Tech_Week_2020_08-09-2020_with_Reprint-permission_for_upload.pdf AN - OPUS4-51233 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Bonse, Jörn A1 - Kirner, Sabrina V. A1 - Krüger, Jörg ED - Sugioka, K. T1 - Laser-induced periodic surface structures (LIPSS) N2 - Laser-induced periodic surface structures (LIPSS) are a universal phenomenon and can be generated on almost any material by irradiation with linearly polarized radiation. This chapter reviews the current state in the field of LIPSS, which are formed in a “self-ordered” way and are often accompanying materials processing applications. LIPSS can be produced in a single-stage process and enable surface nanostructuring and, in turn, adaption of optical, mechanical, and chemical surface properties. Typically, they feature a structural size ranging from several micrometers down to less than 100 nm and show a clear correlation with the polarization direction of the light used for their generation. Various types of LIPSS are classified, relevant control parameters are identified, and their material-specific formation mechanisms are analyzed for different types of inorganic solids, i.e., metals, semiconductors, and dielectrics. Finally, technological applications featuring surface functionalization in the fields of optics, fluidics, medicine, and tribology are discussed. KW - Laser-induced periodic surface structures (LIPSS) KW - Laser ablation KW - Femtosecond laser KW - Nanostructures KW - Microstructures PY - 2020 SN - 978-3-319-69537-2 DO - https://doi.org/10.1007/978-3-319-69537-2_17-1 SP - 1 EP - 59 PB - Springer Nature CY - Cham, Switzerland ET - 1 AN - OPUS4-51332 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Lasagni, A. F. T1 - Editorial: Laser micro- and nano-material processing – Part 1 N2 - This special issue of Advanced Optical Technologies (AOT) is dedicated to the field of laser-based micro- and nanostructuring methods. KW - Laser processing KW - Microstructures KW - Nanostructures KW - Applications PY - 2020 DO - https://doi.org/10.1515/aot-2020-0009 SN - 2193-8576 SN - 2193-8584 VL - 9 IS - 1-2 SP - 7 EP - 9 PB - De Gruyter CY - Berlin AN - OPUS4-50797 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lasagni, A. F. A1 - Bonse, Jörn T1 - Editorial: Laser micro- and nano-material processing – Part 2 N2 - This special issue of Advanced Optical Technologies (AOT) is dedicated to the field of laser-based micro- and nanostructuring methods. KW - Applications KW - Laser processing KW - Microstructures KW - Nanostructures PY - 2020 DO - https://doi.org/10.1515/aot-2020-0025 SN - 2193-8576 SN - 2193-8584 VL - 9 IS - 3 SP - 111 EP - 112 PB - De Gruyter CY - Berlin AN - OPUS4-50995 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR ED - Pfeffer, M. ED - Bonse, Jörn ED - Lasagni, A. F. T1 - Topical issue: Laser micro- and nano-material processing - Part 2 N2 - This special issue of Advanced Optical Technologies (AOT) is dedicated to the field of laser-based micro- and nanostructuring methods. KW - Applications KW - Laser processing KW - Microstructures KW - Nanostructures PY - 2020 UR - https://www.degruyter.com/view/journals/aot/9/3/aot.9.issue-3.xml SN - 2193-8576 SN - 2193-8584 VL - 9 IS - 3 SP - 111 EP - 153 PB - De Gruyter CY - Berlin AN - OPUS4-50997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kunz, C. A1 - Bonse, Jörn A1 - Spaltmann, Dirk A1 - Neumann, C. A1 - Turchanin, A. A1 - Bartolomé, J. F. A1 - Müller, F. A. A1 - Gräf, S. T1 - Tribological performance of metal-reinforced ceramic composites selectively structured with femtosecond laser-induced periodic surface structures N2 - The impact of femtosecond (fs) laser-induced periodic surface structures (LIPSS) on tribological properties was investigated for metal-reinforced ceramic composites (Al2O3-ZrO2-Nb). For this purpose, the metallic niobium (Nb) phase was selectively structured with LIPSS in an air environment with different values of the fs-laser peak fluence by near-infrared fs-laser radiation (λ = 1025 nm, τ = 300 fs, frep = 1 kHz), taking advantage of the different light absorption behavior of ceramic and metal. The tribological performance was evaluated by reciprocating sliding tests in a ball-on-disc configuration using Ringer's solution as lubricant. The surfaces were characterized before and after laser irradiation by optical microscopy, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy and by measuring the contact angle with Ringer's solution. The LIPSS formation resulted in an increased wetting of the surface with the lubricant. Moreover, the selectively structured composite surfaces revealed a coefficient of friction significantly reduced by a factor of ~3 when compared to the non-irradiated surface. Furthermore, the formation of a laser-induced oxidation layer was detected with NbO as the most prominent oxidation state. Selectively structured composites with outstanding mechanical properties and enhanced tribological performance are of particular interest for biomedical applications. KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser ablation KW - Ceramic matrix composites KW - Tribology PY - 2020 DO - https://doi.org/10.1016/j.apsusc.2019.143917 SN - 0169-4332 SN - 1873-5584 VL - 499 IS - 1 SP - 143917 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-49255 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias T1 - Recap: Main Results of the BUMP Study and Relevance for VERBATIM N2 - Zusammenfassung des Forschungsprojekts BUMP hinsichtlich der Relevanz für das Projekt VERBATIM N2 - BUMP had been a theoretical prestudy on open issues for the pile tip buckling of large monopiles. The presentation summarizes the main results and considers the impact for the ongoing VERBATIM project. VERBATIM is set up as a mainly experimental verification project for pile buckling. T2 - Kick-Off Projekt VERBATIM CY - BAM, Berlin, Germany DA - 23.01.2020 KW - Buckling piles circular shells PY - 2020 AN - OPUS4-50515 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stratakis, E. A1 - Bonse, Jörn A1 - Heitz, J. A1 - Siegel, J. A1 - Tsibidis, G.D. A1 - Skoulas, E. A1 - Papadopoulos, A. A1 - Mimidis, A. A1 - Joel, A.-C. A1 - Comanns, P. A1 - Krüger, Jörg A1 - Florian, C. A1 - Fuentes-Edfuf, Y. A1 - Solis, J. A1 - Baumgartner, W. T1 - Laser engineering of biomimetic surfaces N2 - The exciting properties of micro- and nano-patterned surfaces found in natural species hide a virtually endless potential of technological ideas, opening new opportunities for innovation and exploitation in materials science and engineering. Due to the diversity of biomimetic surface functionalities, inspirations from natural surfaces are interesting for a broad range of applications in engineering, including phenomena of adhesion, friction, wear, lubrication, wetting phenomena, self-cleaning, antifouling, antibacterial phenomena, thermoregulation and optics. Lasers are increasingly proving to be promising tools for the precise and controlled structuring of materials at micro- and nano-scales. When ultrashort-pulsed lasers are used, the optimal interplay between laser and material parameters enables structuring down to the nanometer scale. Besides this, a unique aspect of laser processing technology is the possibility for material modifications at multiple (hierarchical) length scales, leading to the complex biomimetic micro- and nano-scale patterns, while adding a new dimension to structure optimization. This article reviews the current state of the art of laser processing methodologies, which are being used for the fabrication of bioinspired artificial surfaces to realize extraordinary wetting, optical, mechanical, and biological-active properties for numerous applications. The innovative aspect of laser functionalized biomimetic surfaces for a wide variety of current and future applications is particularly demonstrated and discussed. The article concludes with illustrating the wealth of arising possibilities and the number of new laser micro/nano fabrication approaches for obtaining complex high-resolution features, which prescribe a future where control of structures and subsequent functionalities are beyond our current imagination. KW - Biomimetic surfaces KW - Laser processing KW - Surface functionalization KW - Bioinspiration KW - Bionic materials PY - 2020 DO - https://doi.org/10.1016/j.mser.2020.100562 SN - 0927-796X VL - 141 SP - 100562-1 EP - 100562-47 PB - Elsevier B.V. AN - OPUS4-50927 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thiele, Marc T1 - Fatigue crack detection methods for high-cyclic loaded steel structures and challenges in mechanical testing N2 - For the generation of renewable energy offshore wind farms play an important role. The majority of these wind generators are connected to steel foundation structures. Steady increasing power output of these wind turbines leads to new challenges as well for engineers of the related support structures. Caused by the high-cyclic loading of these structures by wind and waves fatigue plays a very important role. Besides the consideration of fatigue within the design process it is additionally an important topic and challenge to monitor the existing steel structures relating to potential fatigue cracks occurring during their lifetime. This plays a role for a fundamental understanding of mechanisms as investigated in testing but also for inspection in real structures. Since the structures of the offshore wind generators are very large and in addition partially under water effective and reliable methods for fatigue crack detection are required. This contribution will present results of recent investigations on different crack detection methods applied on high-cycle fatigue tests on small welded steel samples as well as on welded steel components. The comparison of these measurements will show what are the advantages and disadvantages of the different methods and which method is potentially more suitable for the application on real offshore wind structures. It is outlined where challenges for detection methods exist. Furthermore, in this context the resulting challenges for the execution of material testing especially caused by the increasing dimensions of wind energy converters will by exemplarily presented. T2 - EERA JP Wind & SETWind Online Annual Event 2020 CY - Online meeting DA - 14.09.2020 KW - Fatigue KW - Crack detection KW - Steel structures PY - 2020 AN - OPUS4-51356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller-Vahl, H. F. A1 - Strangfeld, Christoph A1 - Nayeri, C. N. A1 - Paschereit, C. O. A1 - Greenblatt, D. T1 - Dynamic Stall Under Combined Pitching and Surging N2 - Dynamic stall often occurs under conditions of simultaneous unsteady pitching and surging (e.g., rotorcraft and wind turbines), butmanymodels employ a dimensionless time base that implicitly assumes that surging is superimposed, in a quasi-steady manner, on dynamic pitching. An unsteady wind tunnel was used to examine this assumption, where a technique was developed to quantify the unsteady effects of surging on a pitching NACA 0018 airfoil. The technique involved performing multiple harmonic pitching experiments under nominally steady freestream conditions that bracketed a corresponding 50% surging amplitude (1.25 ⋅ 105 ≤ Re ≤ 3.75 ⋅ 105). By interpolating these data, unsteady-pitching/quasi-steady-surging data sets were constructed and compared with de facto synchronous pitch and surging experiments, thereby isolating the unsteady effects of surging on a pitching airfoil. Both large and small poststall maximum angles of attack (αs + 5° and αs + 15°) were considered at multiple pitch-surge phase differences. During deep dynamic stall (αs � 15°), with large-scale separation, surging was seen to have a secondary effect on the unsteady aerodynamics. However, at small poststall maximum angles of attack (αs + 5°), either light or deep dynamic stall behavior was observed depending upon the pitch-surge phase difference. This was attributed to Reynolds number history effects, exemplified by boundary-layer transition, and thus it can be referred to as “transitional” dynamic stall. KW - Dynamic stall KW - Angle of attack oscillations KW - Free stream velocity osciallations PY - 2020 DO - https://doi.org/10.2514/1.J059153 VL - 58 IS - 12 SP - 5134 EP - 5145 PB - American Institute of Aeronautics and Astronautics AN - OPUS4-51037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nerger, Deborah A1 - Moosavi, Robabeh A1 - Bracklow, F. A1 - Hering, M. A1 - Kühn, T. A1 - Curbach, M. A1 - Hille, Falk A1 - Rogge, Andreas T1 - Planar tomography and numerical analysis for damage characterization of impact loaded RC plates N2 - The damage analysis of reinforced concrete (RC) is of high interest for reasons of effective maintenance and structural safe-ty of buildings. The damage structures of RC plates loaded by an impact were investigated, applying X-ray planar tomogra-phy and finite element method (FEM). Planar tomography allows getting three-dimensional information of the RC elements and the damage including crack, spalling and scabbing. The FEM model validated on the tomography data justifies the appli-cation for further predictions of the damage description. In this study, we investigated concrete plates of three different thick-ness subjected to impacts at different low- and medium-velocity, whereby the used impactor had a flat tip, which resulted in small penetrations on the front side and scabbing on the rear side. In order to quantify the damage, the damage volume and its distribution through the plate were computed and the correlations between degree of damage and impact velocity were found out. KW - Impact KW - Damage characterization KW - Planar tomography KW - Numeric simulation KW - Reinforced concrete structure PY - 2020 DO - https://doi.org/10.1002/cend.202000017 VL - 8 SP - 1 EP - 19 PB - Wiley AN - OPUS4-51117 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nerger, Deborah A1 - Hille, Falk A1 - Moosavi, Robabeh A1 - Grunwald, Marcel A1 - Redmer, Bernhard A1 - Kühn, T. A1 - Hering, M. A1 - Bracklow, F. T1 - Post-impact evaluation at RC plates with planar tomography and FEM N2 - Due to the wide range of applications, the easy production and the large field of use, reinforced concrete (RC) is a widespread building material. This variety of applications is reflected in a wide range of physical material properties. Not only therefor it still is a technical challenge to provide all necessary test conditions for experimentally reproducing dynamic effects under impact loading of RC structures. In this paper we present investigations on the thicknesses of RC plates under low and medium high velocity impact loading by a flat-tipped impactor. The planar tomography setup at BAM is used to visualize the impact damage and to characterize the damage features such as cracks, scabbing and spalling. Further, the comparison of tomography results with those of an applied numeric simulation analysis is used to verify the numeric models for future damage prognosis under impact loading. Using the results of both, the tomographic as well as the FE analysis, different damage features were investigated and compared regarding their validity. Crack damage plays a leading part and the significance of summarized crack values as well as their distribution is analyzed. The total damage value but also the determined damage distribution both provide an input for describing damage as a function of the impactor velocity and plate thickness. KW - Reinforced concrete structure KW - Post-impact evaluation KW - Damage characterization KW - Ansys Autodyn KW - Drucker-Prager KW - Planar tomography PY - 2020 DO - https://doi.org/10.1016/j.matpr.2020.05.671 SP - 1 EP - 10 PB - Elsevier AN - OPUS4-51115 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ghafafian, Carineh T1 - Damage Mechanisms of Scarf Joint Repairs for Wind Turbine Rotor Blade Shell Applications N2 - Wind turbine rotor blades, made of fiber reinforced polymers (FRP), often fail before their projected 20-year lifespan, largely due to defects that originate during manufacturing and are propagated by operational fatigue and environmental conditions. The cost-intensive replacement outcomes lead to a high loss of earnings, and are one of the inhibitors of wind turbine production [1]. A potential repair alternative is to locally patch these areas of the blades with adhesively bonded structural repairs. However, the effects of such repair methods of the outer shell region on the structural integrity of the rotor blades are still largely unknown, and are thus investigated in this project. The shell components of rotor blades are made of FRP composite material sandwiching a lightweight core, often a rigid foam or Balsa wood. The repair methods involve replacing the lost load path with a new material that is joined to the parent structure [2]. Repairs in this project focus on the scarf method, which allow for a smoother load distribution across the joint, aiming to study the damage mechanism of glass FRP scarf repairs for wind turbine blade shell applications. Namely, the source and path of the damage initiation and propagation, role of the interface between parent and patch material, and the role of the fiber orientation mismatch at this interface are examined. Biaxial ±45° and 0/90° FRP specimens are produced with the vacuum-assisted resin infusion (VARI) process using E-glass non-crimp fabric. The patch layers are then joined using VARI with a scarf ratio of 1:50, using glass FRP fabric with half the areal weight of the parent side to allow for better drapability. The methods and practices in specimen production are based on common industry practice in rotor blade shell manufacturing and repairs. The specimens are tested under uniaxial tensile load, during which they are periodically monitored for damage onset. A comparison of the ±45° and 0/90° specimens allows for an understanding of the role of a highly mismatching fiber orientation in the transition zone between parent and patch material on the failure mechanism of the scarf joint. Although failure in both orientations begins as delamination at the joint edge, the difference in the mechanisms at play in the two different specimen types leads ultimately to different fracture paths. Namely, in the inter fiber failure mechanism of the ±45° specimens, the higher interlaminar strength compared to the intralaminar strength of the laminate leads to intralaminar failure of the ±45° scarf joint specimens. Alternatively, the competition in the 0/90° specimens lies between the interlaminar strength and fiber failure strength, and here we experience failure primarily across the scarf joint length. The scarf joint in the 0/90° specimens disrupts the continuity of the load-carrying 0° layers, directing the failure path to remain primarily along the scarf joint. Experimental results are compared to finite element analyses of scarf patch repairs on glass FRP sandwich specimens with the same respective layup orientations, where the damage initiation regions are identified and correlated to fiber orientation, serving as a bridge to future work which will experimentally examine the scarf repair patches on sandwich shell specimens. T2 - Joint Event: ICCS23 - 23rd International Conference on Composite Structures & MECHCOMP6 - 6th International Conference on Mechanics of Composites CY - Online meeting DA - 01.09.2020 KW - Wind turbine blade shells KW - Glass fiber reinforced polymers KW - Scarf repairs PY - 2020 AN - OPUS4-51175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Popiela, Bartosz T1 - FEM-Analyse der Reparaturstellen an FKV-Sandwichplatten N2 - Untersuchung des Einflusses des Reparaturpatches auf das Verhalten der reparierten GFK-Sandwichproben unter Zug-, Druck- und Schubbeanspruchung. T2 - 25. Nationales SAMPE-Symposium CY - Kassel, Germany DA - 18.02.2020 KW - Rotorblätter KW - Glasfaserverstärkter Kunststoff KW - Sandwichstruktur PY - 2020 AN - OPUS4-50544 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lozano-Martín, D. A1 - Martín, M. C. A1 - Chamorro, C. R. A1 - Tuma, Dirk A1 - Segovia, J. J. T1 - Speed of sound for three binary (CH4 + H2) mixtures from p = (0.5 up to 20) MPa at T = (273.16 to 375) K N2 - Speed of sound is one of the thermodynamic properties that can be measured with least uncertainty and is of great interest in developing equations of state. Moreover, accurate models are needed by the H2 industry to design the transport and storage stages of hydrogen blends in the natural gas network. This research aims to provide accurate data for (CH4 + H2) mixtures of nominal (5, 10, and 50) mol-% of hydrogen, in the p = (0.5 up to 20) MPa pressure range and with temperatures T = (273.16, 300, 325, 350, and 375) K. Using an acoustic spherical resonator, speed of sound was determined with an overall relative expanded (k = 2) uncertainty of 220 parts in 10^6 (0.022%). Data were compared to reference equations of state for natural gas-like mixtures, such as AGA8-DC92 and GERG-2008. Average absolute deviations below 0.095% and percentage deviations between 0.029% and up to 0.30%, respectively, were obtained. Additionally, results were fitted to the acoustic virial equation of state and adiabatic coefficients, molar isochoric heat capacities and molar isobaric heat capacities as perfect-gas, together with second and third acoustic virial coefficients were estimated. Density second virial coefficients were also obtained. KW - Speed of sound KW - Acoustic resonator KW - Heat capacity PY - 2020 DO - https://doi.org/10.1016/j.ijhydene.2019.12.012 SN - 0360-3199 VL - 45 IS - 7 SP - 4765 EP - 4783 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-50454 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lozano-Martín, D. A1 - Akubue, G. U. A1 - Moreau, A. A1 - Tuma, Dirk A1 - Chamorro, C. R. T1 - Accurate experimental (p, rho, T) data of the (CO2 + O2) binary system for the development of models for CCS processes N2 - The limited availability of accurate experimental data in wide ranges of pressure, temperature, and composition is the main constraining factor for the proper development and assessment of thermodynamic models and equations of state. In the particular case of carbon capture and storage (CCS) processes, there is a clear need for data sets related to the (carbon dioxide + oxygen) mixtures that this work aims to address. This work provides new experimental (p, rho, T) data for three binary (CO2 + O2) mixtures with mole fractions of oxygen x(O2) = (0.05, 0.10, and 0.20) mol/mol, in the temperature range T = (250 to 375) K and pressure range p = (0.5 to 13) MPa. The measurements were performed with a high-precision single-sinker densimeter with magnetic suspension coupling. The density data were obtained with estimated expanded relative uncertainties of 0.02 % for the highest densities and up to 0.3 % for the lowest ones.The results were compared to the corresponding results calculated by the current reference equations of state for this kind of mixtures, namely the EOS-CG (combustion gases) and the GERG-2008 equation of state, respectively. The EOS-CG yields better estimations in density than the GERG-2008 equation of state. The results from the EOS-GC model show no systematic temperature dependence. For the GERG-2008 model, however, this criterion is significantly less fulfilled. KW - carbon capture and storage KW - single-sinker densimeter KW - equation of state PY - 2020 DO - https://doi.org/10.1016/j.jct.2020.106210 SN - 0021-9614 VL - 150 SP - 106210 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-50925 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schaumann, P. A1 - Schürmann, K. A1 - Pittner, Andreas A1 - Rethmeier, Michael T1 - Experimental investigations on the fatigue resistance of automatically welded tubular X-joints for jacket support structures N2 - The development within the offshore wind sector towards more powerful turbines combined with increasing water depth for new wind parks is challenging both the designer as well as the manufacturer of bottom fixed support structures. Besides XL-monopiles, the market developed an innovative and economic jacket support structure which is based on automatically manufactured tubular joints combined with standardized pipes. Besides the improvements for a serial manufacturing process the automatically welded tubular joints show a great potential in terms of fatigue resistance e.g. due to a smooth weld geometry without sharp notches. However, these benefits are not considered yet within the fatigue design process of automatically manufactured jacket substructures according to current standards due to the lack of suitable S-N curves. Therefore, 32 axial fatigue tests on single and double-sided automatically welded tubular X-joints have been performed to determine a new hot spot stress related S-N curve. Based on these constant amplitude fatigue tests a new S-N curve equal to a FAT 126 curve was computed which implicitly includes the benefits of the automatically welding procedure. T2 - EERA Deep Wind 2020 CY - Trondheim, Norway DA - 15.01.2020 KW - Notch stress approach KW - Fatigue tests KW - Automated manufacturing KW - Tubular X-joints KW - Structural stress approach PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518509 DO - https://doi.org/10.1088/1742-6596/1669/1/012022 VL - 1669 SP - 012022 PB - IOP Publishing Ltd AN - OPUS4-51850 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Baeßler, Matthias A1 - Cuéllar, Pablo A1 - Victor, A. A1 - Lüddecke, F. ED - Triantafyllidis, T. T1 - Stability and large deformations of slender structures supported by soil materials N2 - The stability and geometric nonlinearities of slender structures are a major topic in structural design. While this topic is most relevant in the field of Structural Engineering, e.g. for steel or concrete structures, only few applications take the role of soil-structure-interaction explicitly into account. The focus of this paper is placed on the impact of soil support and its modelling for the buckling analysis based on examples both for pile foundations and for railway track stability. The general interaction between steel design and the geotechnical input will be addressed. The paper discusses and summarizes a range of subtopics based on experience and current research at the author’s institute. KW - Buckling soil-structure-interaction offshore piles track PY - 2020 SN - 978-3-030-28515-9 SN - 978-3-030-28516-6 DO - https://doi.org/10.1007/978-3-030-28516-6 SN - 1613-7736 SN - 1860-0816 VL - 91 SP - 355 EP - 369 PB - Springer CY - Cham, Switzerland AN - OPUS4-49166 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thomas, Sebastian T1 - Improvement of Type Approval Regulations of Pressure Vessels for Hydrogen Fueled Vehicles using Probabilistic Methods N2 - Composite pressure vessels (CPVs) are becoming the state of the art for storage for compressed hydrogen (CH2) in automotive applications. There is a strong interest of car manufacturers to use lightweight and less-costly gas storage units. In order to reduce the necessary amount of expensive carbon fibre, the nominal safety margins are becoming gradually smaller, pushing the limits of the regulations for type approval. At the same time, the total volume of these vessels increases to extend the range of the vehicles, increasing the consequences for worst-case scenarios like the rupture of the CPVs in service. This presentation presents insights gained in the project “TAnk HYdrogen Automotive” (TAHYA). Its aim is to improve the safety of current regulations for type approval of pressure vessels for the use in hydrogen fueled vehicles, namely GTR No. 13 and ECE R 134. For the assessment of safety, the probabilistic approach developed by division 3.5 of BAM is used. Monte-Carlo-Simulations were conducted leading to the identification of several weak spots, mainly found in the burst test and the batch test. By changing the requirements for burst tests and the approach for batch tests, the identified weak spots can be strongly reduced. T2 - Colloquium of Department 3 CY - Online meeting DA - 19.11.2020 KW - Monte-Carlo Simulation KW - Safety Assessment KW - Pressure Vessel PY - 2020 AN - OPUS4-51696 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Quercetti, Thomas A1 - Wille, Frank A1 - Neumann, Martin A1 - Linnemann, Konrad ED - Baraldi, P. ED - Di Maio, F. ED - Zio, E. T1 - Safety Evaluation of a Package for Radioactive Waste by Full-Scale Drop Testing N2 - As part of the evaluation of a package for the safe transport of radioactive waste the regulations of the IAEA International Atomic Energy Agency shall be fulfilled. The regulations define requirements for the package and specify mechanical and thermal test conditions. Different methods are allowed for the test performance to demonstrate compliance with the regulations. Next to calculational approaches and the use of models of an appropriate scale, the performance of full-scale testing with prototype packages respectively full-scale models is applied. The use of full-scale models has several advantages within the complete safety assessment procedure for a transport package approval. Scaling and corresponding similarity questions don’t have to be considered, additional material investigations can be limited and analyses to transfer test results to the original package design are reduced in number and complexity. Additionally, experience for future serial design procedures can be built up during manufacturing and assembling of the test model. BAM operates different drop and fire test facilities south of Berlin, Germany. BAM has started to perform a drop test campaign with a full-scale model of 120 metric tons weight for a transport package approval procedure. The paper describes experience with test preparation, drop performance and additional analyses. The measurement concept is explained and test goals regarding the package safety assessment and evaluation of safety margins are introduced. T2 - 30th European Safety and Reliability Conference and 15th Probabilistic Safety Assessment and Management Conference (ESREL2020 PSAM15) CY - Online meeting DA - 01.11.2020 KW - Slap-down KW - Transport safety KW - Package KW - Drop test KW - Similarity KW - FEA KW - Radioactive waste PY - 2020 UR - https://www.rpsonline.com.sg/proceedings/esrel2020/html/3809.xml SN - 987-981-14-8593-0 SP - Paper 3809,1 EP - 8 PB - Research Publishing Services CY - Singapore AN - OPUS4-50981 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krebber, Katerina A1 - Weege, S. A1 - Großwig, S. A1 - Obermöller, M. A1 - Perk, M. A1 - Lu, Xin A1 - Schukar, Marcus A1 - Weber, U. A1 - Pfeiffer, T. A1 - Rembe, M. T1 - Kombinierte faseroptische Messungen in Bohrlöchern helfen bei der Detektion von Kleinstleckagen N2 - Seit November 2019 läuft ein breit angelegtes und vom BMWi gefördertes ZIM-Kooperationsprojekt zwischen der Bundesanstalt für Materialforschung und -prüfung (BAM), der IAB'Weimar gGmbH, der GKSO GmbH & Co. Projekt KG, der DEEP.KBB GmbH sowie der Rembe Consulting PartG mbB. Ziel des Forschungsvorhabens sind sowohl die Lokalisierung als auch die Quantifizierung insbesondere sehr kleiner Leckagen in einer Bohrlochverrohrung durch die Nutzung faseroptischer Messtechnik. Durch Messdatenkopplung und den Wegfall bewegungsbedingter Nachteile einer Messsonde werden wesentlich präzisere Ergebnisse zur Bewertung der Bohrlochintegrität als üblich erwartet. T2 - DGMK/ÖGEW-Frühjahrstagung 2020 CY - Meeting was canceled DA - 15.04.2020 KW - Wasserstoffspeicher KW - Kavernenspeicher KW - Verteilte faseroptische akustische Sensorik PY - 2020 VL - 6 SP - 43 EP - 43 PB - DVV Media Group CY - Hamburg AN - OPUS4-52233 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mair, Georg W. A1 - Becker, B. A1 - John, Sebastian A1 - Duffner, Eric T1 - Composite storage systems for compressed hydrogen - systematic improvement of regulations for more attractive storage units N2 - Hydrogen is an attractive energy carrier that requires high effort for safe storage. Forensuring safety, they must undergo a challenging approval process. Relevant standardsand regulations for composite cylinders used for the transport of hydrogen and for its on-board storage are currently based on deterministic (e.g. ISO 11119-3) or semi-probabilistic(UN GTR No. 13) criteria. This paper analysis the properties of such methods withrespect to the evaluation of load cycle strength. Their characteristics are compared withthe probabilistic approach of the BAM. Based on Monte-Carlo simulations, the availabledesign range (mean value and scatter of strength criteria) of current concepts was exem-plarily estimated. The aspect of small sample sizes is analysed and discussed with respectto the evaluation procedures. KW - Probabilistic KW - Monte-Carlo KW - Regulations KW - Composite cylinder KW - Hydrogen vehicles KW - Transport of dangerous goods PY - 2020 DO - https://doi.org/10.1016/j.ijhydene.2018.04.068 SN - 0360-3199 VL - 45 IS - 25 SP - 13672 EP - 13679 PB - Elsevier Ltd. AN - OPUS4-50687 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mair, Georg W. T1 - Markthochlauf von Wasserstoff - Vertrauen durch probabilistische Sicherheitsbewertung der H2-Speicher N2 - Der Vortrag beginnt mit dem erwarteten Bedarf an Wasserstoff und der Frage der Risikosteuerung bei stattfindender Marktdurchsetzung. Dem gegenüber ist an einem Beispiel der Prozess der Regelsetzung gestellt, was die Notwendigkeit pro-aktiven Handelns zeigt. Es wird über die risikobasierte Definition von Sicherheit gezeigt, welche Bedeutung die Erfassung der Fertigungsstreuung hat und wie die quantitative Erfassung und Bewertung aussehen könnte. Zuletzt wird über den Aspekt der Alterung auf das Potential probabilistischer Zulassungsansätze verwiesen und aufgezeigt, wie die Wirkung von Vorschriften nach dem probabilistischen Sicherheitskriterium bewertet und optimiert werden kann. T2 - 9. HYPOS-Dialog: Grüner Wasserstoff, aber sicher! (Uni Magdeburg) CY - Magdeburg, Germany DA - 11.09.2020 KW - Wasserstoffspeicher KW - Monte-Carlo-Experiment KW - Lebensdauervorhersage KW - Statistische Bewertung KW - Sicherheit KW - Population PY - 2020 AN - OPUS4-53154 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gumenyuk, Andrey T1 - New developments in high power laser and hybrid welding of thick plates for application in modern ship building N2 - High power laser beam welding has been already introduced in ship building industry since last two decades and is characterized by higher performance as conventional arc welding technologies through its higher welding speed, penetration depth and therefore higher productivity. Moreover, high quality weld joints are achievable thanks to a stronger automatization degree and better repeatability of the process. A further advantage of the laser beam welding is a manufacturing of parts with very low distortion according to much lower heat input, so that rework amount can be reduced significantly. Nevertheless, there are still some unresolved problems limiting the range of application of the technology in part manufacturing within ship building industry, restricted by development and application of new materials or new design of ship vessels. The present contribution deals with some novel aspects of laser beam welding technology allowing to widen this range significantly. One of the possibilities is to increase the weld seam thickness for single pass laser or laser-hybrid welding is to apply contactless EM-support system based on generation of the Lorentz force counteracting the liquid metal drop out. Also, application of laser-hybrid welding technology for welding novel materials like cold resistant steel X8Ni9 used for construction of LNG tanks brings technological and design advantages comparing to conventional welding technologies by using of a similar alloyed filler wire instead of expensive Ni-based filler material. Finally, it is shown how the application of computational techniques can be used to helps to improve the quality of laser welded joints and avoid the critical weld failure by optimization of the welding process parameters. T2 - SHY Virtual Laserforum 2020 CY - Online meeting DA - 01.09.2020 KW - Ship building KW - Laser beam welding KW - Hybrid laser arc welding PY - 2020 UR - https://laserforum.mobieforum.fi/ AN - OPUS4-51221 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Schaumann, P. A1 - Schürmann, K. A1 - Pittner, Andreas A1 - Rethmeier, Michael T1 - Quantifizierung der Einflüsse aus Fertigungsautomatisierung und Innenschweißen auf die Ermüdungsfestigkeit von Hohlprofilknoten für Offshore-Windenergieanlagen T1 - Quantifying the effects of manufacturing automation and internal welding on the fatigue resistance of circular hollow section joints for offshore wind energy converters N2 - Die Entwicklung in der Offshore-Windenergie hin zu größeren, leistungsstärkeren An-lagentypen sowie die zeitgleich zunehmenden Wassertiefen der projektierten Wind-parks stellt u. a. Designer und Fertiger der Gründungsstrukturen von Windenergiean-lagen vor wachsende Herausforderungen. Neben dem Gründungskonzept der XL-Monopiles rückt wegen der Kombination aus dem vergleichsweise geringen Materialverbrauch bei gleichzeitig hoher Steifigkeit, auch die Jacketgründung in den Fokus. Der Fertigungsaufwand der Jackets ist verglichen mit Monopiles groß; kann jedoch durch die Nutzung von Standardrohren mit automatisiert gefertigten Jacketknoten reduziert werden. Vor diesem Hintergrund beschreibt der vorliegende Forschungsbericht den Fertigungs-prozess zum automatisierten Schweißen von X-förmigen Hohlprofilknoten für Jacket-Gründungsstrukturen von Offshore-Windenergieanlagen. Ein weiteres wesentliches Ziel dieses Vorhabens war die konsequente Digitalisierung der schweißtechnischen Fertigungskette während der automatisierten Schweißung der X-Knoten. Die so ge-speicherten Prozessparameter können zum einen als Grundlage einer Qualitätskon-trolle dienen, zum anderen ermöglichen sie eine vollständige Nachverfolgbarkeit der automatisiert gefertigten Rohrknoten. Der zweite maßgebend in diesem Bericht behandelte Aspekt umfasst die Quantifizie-rung der Einflüsse aus Fertigungsautomatisierung und Innenschweißen auf die Ermü-dungsfestigkeit der Hohlprofilknoten auf Basis serieller Ermüdungsversuche. Dazu wurden im Projekt zwei Serien mit jeweils 16 Schwingversuchen an ein- und doppel-seitig automatisiert geschweißten X-Knoten durchgeführt und entsprechende Struktur-spannungswöhlerlinien für die automatisiert gefertigten X-Knoten bestimmt. Die Ergebnisse dieser Ermüdungsversuche werden abschließend in numerischen Untersuchungen auf Basis der Strukturspannungs- und des Kerbspannungskonzeptes gegenübergestellt, um die Prognosefähigkeit beider Konzepte für die ermüdungs-kritischen Bereiche des X-Knotens bewerten zu können. Durch die im Forschungsvorhaben durchgeführten schweißtechnischen, experimen-tellen und numerischen Analysen konnte das Potential automatisiert gefertigter Rohr-knoten hinsichtlich Reproduzierbarkeit und Ermüdungsverhalten quantifiziert werden. Zusätzlich konnte der Einfluss der inneren Schweißnaht auf die Ermüdungsfestigkeit bewertet werden. N2 - The development within the offshore wind sector towards more powerful turbines combined with increasing water depth for new wind parks is challenging both the designer as well as the manufacturer of bottom fixed support structures. Besides XL-monopiles, the market developed an innovative and economic jacket support structure, which is based on automatically manufactured tubular joints combined with standardized pipes. Besides the improvements for a serial manufacturing process the automatically welded tubular joints show a great potential in terms of fatigue resistance e.g. due to a smooth weld geometry without sharp notches. However, these benefits are not considered yet within the fatigue design process of automatically manufactured jacket substructures according to standards and guidelines due to the lack of suitable S-N curves. Therefore, within this research project the automatically welding process of tubular joints for jacket support structures of offshore wind energy turbines was developed. Additionally, the project was focused on a consistent digitalization of the welding production chain during the automated welding of the X-joints. These stored process parameters can then serve as the basis for quality checks and a complete traceability of the automatically produced tubular joints is enabled. The second aspect dealt within this report is the quantification of the effects of production automation and internal welding on the fatigue resistance of the tubular joints by performing serial fatigue tests. For this purpose, two series each with 16 fatigue tests on single- and double-sided automatically welded X-joints were carried out in the project to determine structural stress based S-N curves for the automatically welded X-joints. The results of these fatigue tests are then compared to numerical investigations based on the structural stress as well as notch stress approach. The outcomes are then compared to evaluate the capability of both approaches for the prediction of the fatigue-critical locations within the X-joints. Based on the analysis of the welding procedure as well as the experimental and numerical investigations within this research project, the potential of automatically manufactured tubular joints with regard to reproducibility and fatigue behaviour was investigated. In addition, the effects of an inner root layer on the fatigue resistance was evaluated. KW - Lightweight Design KW - Jacket Support Structures KW - Fatigue KW - Arc Welding Automation KW - Offshore Wind PY - 2020 UR - https://shop.stahldaten.de/produkt/p-1178-quantifizierung-der-einfluesse-aus-fertigungsautomatisierung-und-innenschweissen-auf-die-ermuedungsfestigkeit-von-hohlprofilknoten-fuer-offshore-windenergieanlagen SN - 978-3-946885-79-5 VL - Bericht P1178 SP - 1 EP - 189 AN - OPUS4-51855 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Pittner, Andreas A1 - Rethmeier, Michael T1 - Ökologische Bilanzierung von Schmelzschweißverfahren unter Berücksichtigung vor- und nachgelagerter Prozessschritte N2 - Schweißen ist ein industriell relevantes Fertigungsverfahren mit einer branchenübergreifenden Bedeutung. Die Umweltwirkungen von Schweißverfahren sind jedoch bisher unbekannt und werden im Entstehungsprozess eines Produktes entlang seiner Fertigungskette daher meist nicht berücksichtigt. Ferner ist der Schweißprozess durch einen hohen Verbrauch an Energie sowie Ressourcen gekennzeichnet. Zahlreiche Arbeiten zeigen, dass der Bedarf einer Ökobilanzierung enorm ist. Ursächlich für die bisher mangelhafte Etablierung der Ökobilanzierung von Schweißverfahren und damit Motivation für die Forschungsarbeiten ist die Unkenntnis relevanter Einflussgrößen und damit verbunden ein nicht abschätzbarer Aufwand bei der Durchführung sowie Implementierung einer Ökobilanz im fertigungstechnischen Kontext. Demgegenüber ist die Ökobilanzierung in anderen Branchen ein oft genutztes Werkzeug zur Ableitung von Umweltwirkungen. Aufgrund der aktuellen Diskussionen bezüglich des Übergangs hin zu einer klimaneutralen Produktion erfährt auch die Analyse und Optimierung der Umweltwirkungen schweißtechnischer Fertigungsverfahren derzeit eine gesteigerte Aufmerksamkeit. Für Unternehmen stellt die Verfügbarkeit umweltverträglicher Produkte bzw. Prozesse eine gewisse Werbewirksamkeit dar, wie dies im Bereich der Schweißstromquellentechnik aktuell zu beobachten ist. Gleichzeitig wird das Thema des „green welding“ auch bezogen auf die gesamte Fertigungskette immer häufiger diskutiert. Dies zeigt sich durch eine in den letzten Jahren deutlich gestiegene Publikationsaktivität. Neben Analysen zu den Einflussfaktoren auf die Nachhaltigkeit in schweißtechnischen Produktionsumgebungen stehen vor allem auch konkrete Implementierungen in der Fertigung bzw. der Produktentstehung im Fokus. Die grundlegende Vorgehensweise einer Ökobilanzierung (Life-Cycle-Assessment bzw. Abk. LCA) ist als standardisierte Methode in geltenden Normen] sowie in entsprechender Fachliteratur beschrieben. Kernelement der Ökobilanzierung ist die Sachbilanzierung, d.h. die Erfassung der relevanten Inputs sowie Outputs bezogen auf das System „Schweißprozess“. Aus dem entlang der schweißtechnischen Fertigungskette akkumulierten Ressourcenverbrauch während des Schweißens (z.B. Zusatzwerkstoff, elektrische Energie, Schutzgas, etc.) und Abfallprodukten bzw. Emissionen wird die Umweltwirkung entsprechend verschiedener Kategorien, z.B. dem CO2-Äquivalent, gemäß der World Steel Association abgeleitet. In der schweißtechnischen Community ist es bekannt, dass die Umweltwirkung von Schweißprozessen qualitativ direkt aus dem Ressourcenverbrauch abgeleitet werden kann. Der Einfluss der verschiedenen Input- sowie Outflüsse auf ausgewählte Wirkkategorien ist jedoch nicht ad-hoc quantifizierbar. Die Forschungsarbeiten haben gezeigt, dass der Materialverbrauch (z.B. Grund-/Zusatzwerkstoff, etc.), der Energieverbrauch (z.B. Wirkleistung sämtlicher elektrischer Verbraucher während der Prozesszeit), Gasverbrauch (Prozess-, Schutzgas oder Druckluft) sowie Hilfsmittel (z.B. Schutzgläser) signifikante Inputgrößen darstellen, deren Berücksichtigung im Rahmen einer Prozessökobilanz ausreichend ist. Eine wesentliche Forderung des projektbegleitenden Ausschusses war, Methoden für eine direkte Implementierung, um somit Nachnutzung der Ergebnisse zu entwickeln. Um die Ökobilanzierung als festen Bestandteil in die schweißtechnische Dokumentation einfließen zu lassen, sind die notwendigen Arbeitsschritte zu automatisieren. Daher wurden im Rahmen der Forschungsarbeiten sämtliche zu berücksichtigenden Größen durch ein an der Forschungsstelle entwickelten Schweißdatenmanagements digital erfasst sowie archiviert und in eine Umweltwirkung durch Zugriff auf entsprechende Open-Source Datenbanken „übersetzt“. Das Datenmanagement ermöglicht die eindeutige Zuordnung der Umweltwirkung eines geschweißten Bauteiles ohne Dokumentationsaufwand für den Anwender. Dadurch werden insbesondere KMU in die Lage versetzt, den Anforderungen bezüglich der Bewertung der Ökoeffizienz von Fertigungsverfahren gerecht zu werden und somit auf die nationalen sowie internationalen klimapolitischen Rahmenbedingungen vorbereitet zu sein. Die Analysen eines breiten Spektrums an Schweißverfahren haben gezeigt, dass eine Verringerung der Umweltwirkungen von Schweißverfahren demnach nur primär durch eine Reduktion des Zusatzwerkstoff- sowie Energieverbrauches zu realisieren ist. Hierbei zeigen Verfahren mit niedrigem Werkstoffeinsatz, im Extremfall autogene Verfahren, die geringsten Umweltwirkungen. Im Produktentstehungsprozess ist es daher notwendig, unter Berücksichtigung der Schweißbarkeit die ökologischen Verfahrenscharakteristika hinsichtlich konstruktiver, fertigungstechnischer sowie werkstoffspezifischer Randbedingungen zu bewerten, um die vorgeschriebenen Produkteigenschaften zu gewährleisten und die Umweltbelastung zu minimieren. Damit der Workflow, der bei der Ökobilanzierung zu durchlaufen ist, vereinheitlicht und für jeden verständlich ist, fließen die Forschungsergebnisse direkt in die DIN SPEC 35235 „Nachhaltigkeit in der Schweißtechnik – Ökobilanzierung von Schweißverfahren“ ein. Dies ist die Grundlage, um die Vergleichbarkeit von Ökobilanzen in der Schweißtechnik zu gewährleisten und so deren Akzeptanz in der Industrie zu erhöhen. Damit ist ein optimaler Transfer der Forschungsergebnisse in die Industrie gewährleistet. KW - Schweißverfahren KW - Ökobilanzierung PY - 2020 SP - 1 EP - 38 PB - DVS Media CY - Düsselorf AN - OPUS4-51856 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - John, Sebastian T1 - Delfin - Statusbericht zum 4.HJM N2 - Präsentation über den Fortschritt der BAM zum Vorhaben Delfin, welches sich mit der Entwicklung und Schädigungsneigung von Composite-Wasserstoffbehältern für den Anwendungsfall KFZ beschäftigt T2 - 4. Halbjahresmeeting zum Vorhaben Delfin CY - Online meeting DA - 21.10.2020 KW - Wasserstoff KW - Impact KW - Druckbehälter PY - 2020 AN - OPUS4-51495 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Munzke, Dorit A1 - Duffner, Eric A1 - Eisermann, René A1 - Schukar, Marcus A1 - Schoppa, André A1 - Szczepaniak, Mariusz A1 - Strohhäcker, J. A1 - Mair, Georg W. T1 - Monitoring of type IV composite pressure vessels with multilayer fully integrated optical fiber based distributed strain sensing N2 - We present the results of distributed fiber optic strain sensing for condition monitoring of a hybrid type IV composite fully wrapped pressure vessel using multilayer integrated optical fibers. Distributed strain sensing was performed for a total number of 252,000 load cycles until burst of the vessel. During this ageing test material fatigue could be monitored and spatially localized. Critical material changes were detected 17,000 cycles before material failure. Results have been validated by acoustic emission analysis. T2 - 12th International Conference on Composite Science and Technology (ICCST12) CY - Sorrento, Italy DA - 08.05.2019 KW - Hybrid composite pressure vessel KW - Distributed fiber optic sensing KW - Acoustic emission analysis KW - Structural health monitoring PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-516772 DO - https://doi.org/10.1016/j.matpr.2020.02.872 SN - 2214-7853 VL - 34 SP - 217 EP - 223 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-51677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mair, Georg W. A1 - Thomas, Sebastian T1 - Consequences of the reduced minimum burst pressure on the production surveillance N2 - First the acceptance rates resulting from the analysis of different minimum burst ratios and standards are displayed and explained. Especially the problems resulting from a further reduction if the minimum burst ratio are shown. For a better understanding of these results the process of analysing the acceptance rate is explained in detail. This contains the alleged contradiction between safety of samples due to its scatter while the rejected sample provides a higher mean strength. Then the importance of batch testing is explained and leads to the recommendation to have a strong interaction between provided mean strength and requested maximum of production scatter. T2 - 8 th WG on rev GTR 13 CY - Online meeting DA - 02.03.2020 KW - Minimum burst ratio KW - Production scatter KW - Mean burst pressure KW - Batch testing KW - Acceptance rate PY - 2020 AN - OPUS4-53147 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mair, Georg W. T1 - Bergungsdruckgefäße - Vorschlag zur Definition von Druckgefäßen N2 - Es wird plastisch dargestellt, mit welcher Intention und welchem Ziel Deutschland in die Juni Sitzung des UN ECOSOC SubCom TDG gehen wird, um ein Druckvolumenbegrenzung für Druckgefäße zu erreichen. T2 - BAM-DIN-IGV-DVFG-Jahresgespräch 2020 CY - Berlin, Germany DA - 27.02.2020 KW - Bergungsdruckgefäß KW - Konsequenzbegrenzung KW - Volumenbegrenzung KW - Druck-Volumen-Produkt KW - UN-Modellvorschriften KW - Akzeptanz PY - 2020 AN - OPUS4-53146 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mair, Georg W. A1 - Thomas, Sebastian A1 - Schalau, Bernd A1 - Wang, Bin T1 - Safety criteria for the transport of hydrogen in permanently mounted composite pressure vessels N2 - The recent growth of the net of hydrogen fuelling stations increases the demands to transport compressed hydrogen on road by battery vehicles or tube-trailers, both in composite pressure vessels. As a transport regulation, the ADR is applicable in Europe and adjoined regions, and is used for national transport in the EU. This regulation provides requirements based on the behaviour of each individual pressure vessel, regardless of the pressure of the transported hydrogen and relevant consequences resulting from generally possible worst case scenarios such as sudden rupture. In 2012, the BAM (German Federal Institute for Materials Research and Testing) introduced consequence-dependent requirements and established them in national transport requirements concerning the “UN service life checks” etc. to consider the transported volume and pressure of gases. This results in a requirement that becomes more restrictive as the product of pressure and volume increases. In the studies presented here, the safety measures for hydrogen road transport are identified and reviewed through a number of safety measures from countries including Japan, the USA and China. Subsequently, the failure consequences of using trailer vehicles, the related risk and the chance are evaluated. A benefit-related risk criterion is suggested to add to regulations and to be defined as a safety goal in standards for hydrogen transport vehicles and for mounted pressure vessels. Finally, an idea is given for generating probabilistic safety data and for highly efficient evaluation without a significant increase of effort. T2 - ICHS 2019 CY - Adelaide, Australia DA - 24.09.2019 KW - F-N-diagram KW - Chance-risk analysis KW - Pressure-volume product KW - Limit of acceptable consequence KW - Minimum burst pressure PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-511589 DO - https://doi.org/10.1016/j.ijhydene.2020.07.268 SN - 0360-3199 VL - 46 IS - 23 SP - 12577 EP - 12593 PB - Elsevier Ltd. AN - OPUS4-51158 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönhals, Andreas T1 - Inelastic neutron scattering as a tool to investigate  polymers of intrinsic microporosity for green membrane processes and electronic applications N2 - Polymers with intrinsic microporosity are promising candidates for the active separation layer in green gas separation membranes and as active materials for electronic applicatons. Here, by means of inelastic neutron scattering, the vibrational density of states (VDOS) and the molecular mobility were investigated for PIM-1, the prototypical polymer with intrinsic microporosity. The results are compared to data measured for a more conventional high-performance polyimide used in gas separation membranes (Matrimid). The measured data show the characteristic low frequency excess contribution to the VDOS above the Debye sound wave level, generally known as the Boson peak in glass-forming materials. In comparison to the Boson peak of Matrimid, that of PIM-1 is shifted to lower frequencies. This shift is discussed considering the microporous, sponge-like structure of PIM-1 as providing a higher compressibility at the molecular scale than for conventional polymers. Elastic fixed window scans were measured on a neutron backscattering spectrometer to have an overview about the molecular dynamics at a time scale of ca. 1 ns. The temperature dependence of the estimated mean squared displacement shows a step-like increase in the temperature range from 100 K to 250 K indicating the onset of some molecular mobility. The nature of this motional process was analysed in detail by quasielastic neutron scattering combining Time-of-Flight and backscattering where the data are discussed with regard to both the q- and the temperature dependence. T2 - Symposium on Large Scale Facilities CY - Berlin, Germany DA - 09.03.2020 KW - Polymer membranen PY - 2020 AN - OPUS4-50546 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winckelmann, Alexander T1 - High-resolution optical spectrometry for lithium isotope ratio analysis N2 - An alternative method for lithium isotope amount ratio analysis is proposed by combining atomic absorption spectrometry with spectra data analysis by machine leaning. It is based on the well-known isotope shift of around 15 pm for the electronic transition at wavelength 670.7845 nm which can be measured by a high-resolution continuum source atomic absorption spectrometer (HR-CS-AAS). For isotope amount ratio analysis, a scalable three boosting machine learning algorithm (XGBoost) was employed and calibrated with a set of samples with a 6Li isotope amount fraction ranging from 99% to 6%. The absolute Li isotope amount fractions of these calibration samples were previously measured by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) and used as ab-initio data for the machine learning algorithm. Validation of the machine leaning model was performed with two standard reference materials (LSVEC and IRMM-016). The procedure was employed for the isotope amount ratio determination of a set of stock chemicals (Li2CO3, LiNO3, LiCl, LiOH, and LiF) as well as a BAM candidate LiMNC cathode reference material. Achieved uncertainties are one order of magnitude higher than those obtained by MC-ICP-MS. This precision and accuracy is nonetheless sufficient to resolve natural occurring variations in Lithium isotope ratios. Also, the LiMNC material was analyzed by HR-CS-AAS with and without matrix purification. The results are comparable within statistical error. T2 - Groupseminar - GFZ Potsdam CY - Online Meeting DA - 27.10.2020 KW - Lithium batteries KW - HR-CS-AAS KW - Machine learning KW - Isotope analysis PY - 2020 AN - OPUS4-51572 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - von Preetzmann, N. A1 - Eckmann, P. A1 - Tuma, Dirk A1 - Richter, M. T1 - Thermodynamics of LNG N2 - Densities of eight gravimetrically prepared ternary and quaternary gas mixtures consisting of methane, ethane, propane, and partially nitrogen were investigated along the four isotherms of –250, –230, –210, and –190 °F at pressures of 350, 500, 650, and 1000 psig using a cryogenic single-sinker densimeter. The experimental densities were compared to densities calculated by various models, namely the EOS-LNG fundamental Helmholtz equation of state, the COSTALD correlation, the Lee-Kessler-Plöcker equation of state, and the Peng-Robinson equation of state. The best performance was shown by the EOS-LNG equation of state which is capable of predicting the liquid densities within the specified uncertainty of the model of 0.05 %. The other models, however, showed significant differences that disqualify for calculation within the p,T-region investigated of the gas mixtures. KW - Density measurement KW - Liquefied natural gas-like mixtures KW - Cryogenic state KW - Single-sinker densimeter KW - Equations of state PY - 2020 SP - 1 EP - 55 AN - OPUS4-50741 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pu, Y. A1 - Lawrence, M. J. A1 - Celorrio, V. A1 - Wang, Q. A1 - Gu, M. A1 - Sun, Z. A1 - Agudo Jácome, Leonardo A1 - Russell, A. E. A1 - Huang, L. A1 - Rodriguez, P. T1 - Nickel confined in 2D earth-abundant oxide layers for highly efficient and durable oxygen evolution catalysts N2 - Low cost, high-efficiency catalysts towards water splitting are urgently required to fulfil the increasing demand for energy. In this work, low-loading (<20 wt%) Ni-confined in layered metal oxide anode catalysts (birnessite and lepidocrocite titanate) have been synthesized by facile ion exchange methodology and subjected to systematic electrochemical studies. It was found that Ni-intercalated on K-rich birnessite (Ni-KMO) presents an onset overpotential (ηonset) as low as 100 mV and overpotential at 10 mA cm−2 (η10) of 206 mV in pH = 14 electrolyte. By combining electrochemical methods and X-ray absorption and emission spectroscopies (XAS and XES), we demonstrate Ni sites are the active sites for OER catalysis and that the Mn3+ sites facilitate Ni intercalation during the ion-exchange process, but display no observable contribution towards OER activity. The effect of the pH and the nature of the supporting electrolyte on the electrochemical performance was also evaluated. KW - Confined catalyst KW - Low-loading KW - Layered manganese oxide KW - Oxygen evolution reaction KW - Transmission electron microscopy (TEM) PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515027 DO - https://doi.org/10.1039/D0TA04031B SN - 2050-7496 SN - 2050-7488 VL - 8 IS - 26 SP - 13340 EP - 13350 PB - Royal Society of Chemistry CY - London AN - OPUS4-51502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias T1 - Computational Geomechanics for Offshore Wind N2 - Simulations for the Safety and Efficiency of Foundations in the Offshore Wind Energy Production. T2 - Poster Challenge - EERA JP Wind Online Annual Event 2020 CY - Online meeting DA - 14.09.2020 KW - Numerical simulations KW - Marine geomechanics KW - Offshore wind energy PY - 2020 UR - https://www.eerajpwind.eu/events/eera-jp-wind-setwind-annual-event-2020/ AN - OPUS4-51280 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cuéllar, Pablo T1 - State of the art and development perspectives of deep foundations for offshore wind converters T1 - Estado del arte y perspectivas de desarrollo de las cimentaciones profundas para aerogeneradores offshore N2 - This presentation provides an overview of the main geotechnical aspects associated with deep foundations in the context of offshore wind generation. The most common deep foundation typologies (large diameter monopiles and multipile typologies) as well as new trends under development (e.g. suction buckets) and their current limits will be briefly described. The talk concludes with a brief review of advanced topics not covered in classical pile design, such as hydromechanical coupling effects (pore pressure generation), cyclic accumulation of deformations, cyclic degradation of axial capacity or pile-setup gains. T2 - Ciclo de Conferencias: Aplicaciones de la Geotecnia en la generación de Energía. Sociedad Argentina de Ingeniería Geotécnica SAIG CY - Online meeting DA - 02.12.2020 KW - Offshore wind energy KW - Deep foundations KW - Offshore geomechanics PY - 2020 AN - OPUS4-51729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael A1 - Wetzel, Annica A1 - Oczan, Ozlem A1 - Nietzke, Jonathan A1 - Richter, Tim A1 - Schröpfer, Dirk T1 - Hydrogen diffusion and local Volta potential in high- and medium-entropy alloys N2 - High-entropy alloys (HEAs) are characterized by a solid solution of minimum five and medium-entropy alloys (MEAs) of minimum three principal alloying elements in equiatomic proportions. They show exceptional application properties, such as high-strength and ductility or corrosion resistance. Future HEA/MEA-components could be exposed to hydrogen containing environments like vessels for cryogenic or high-pressure storage where the hydrogen absorption and diffusion in these materials is of interest. In our study, we investigated the HEA Co20Cr20Fe20Mn20Ni20 and the MEA Co33.3Cr33.3Ni33.3. For hydrogen ingress, cathodic charging was applied and diffusion kinetic was measured by high-resolution thermal desorption spectros-copy using different heating rates up to 0.250 K/s. Peak deconvolution resulted in high-temperature desorption peaks and hydrogen trapping above 280 °C. A total hydrogen concentration > 40 ppm was identified for the MEA and > 100 ppm for HEA. This indicates two important effects: (1) delayed hydrogen diffusion and (2) considerable amount of trapped hydrogen that must be anticipated for hydrogen assisted cracking phenomenon. Local electrochemical Volta potential maps had been measured for the hydrogen free condition by means of high-resolution Scanning Kelvin Probe Force Microscopy (SKPFM). T2 - Symposium on Materials and Joining Technology CY - Online meeting DA - 07.09.2020 KW - Hydrogen KW - High-entropy alloy KW - Diffusion KW - Scanning kelvin probe force microscopy KW - Corrosion PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-511684 DO - https://doi.org/10.1088/1757-899X/882/1/012015 VL - 882 SP - 1 EP - 15 PB - IOP Publishing CY - Bristol AN - OPUS4-51168 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Richter, Tim A1 - Schröpfer, Dirk A1 - Rhode, Michael A1 - Börner, Andreas T1 - Influence of modern machining processes on the surface integrity of high-entropy alloys N2 - High Entropy Alloys (HEAs) are a recent class of materials. In contrast to conventional alloys, HEAs consist of five alloying elements in equiatomic equilibrium. The high entropy effect is due, among other things, to the increased configuration entropy, which promotes solid solution formation. Many HEAs have enormous application potential due to excellent structural property combinations from very low to high temperatures. For the introduction of HEAs in real components, however, the question of the applicability of machining production technologies for component manufacture is of central importance. This has so far received Little attention in global materials research. Reliable and safe processing is essential for the demand of economical component production for potential areas of application, e.g. in power plant technology. For metals, milling is the standard machining process. This article presents the results of machining analyses. It focuses on the surface integrity resulting from the milling process on a Co20Cr20Fe20Mn20Ni20-HEA. For this purpose, investigations were carried out using ball nose end milling tools for conventional milling process in comparison to an innovative hybrid process available at BAM Berlin, Ultrasonic-Assisted Milling (USAM). USAM promises a lower Degradation of the surface properties due to lower loads on the workpiece surface during machining. For this purpose, basic milling parameters (cutting speed and tooth feed) were systematically varied and cutting forces were measured during the milling experiments. The subsequent Analysis of these forces allows an understanding of the mechanical loads acting on the tool and component surface. These loads cause topographical, mechanical and microstructural influences on the surface and consequently on the surface integrity. For their characterization, light and scanning electron microscopy were used, and the roughness and residual stresses via X-ray diffraction were measured. The results indicate significant advantages using USAM, especially due to reduced cutting forces compared to the conventional milling process. This causes lower mechanical loads on the tool and surface, combined with lower tensile residual stresses on and below the surface, and ultimately results in a significantly enhanced surface integrity. T2 - Symposium on Materials and Joining Magdeburg 2020 CY - Online meeting DA - 07.09.2020 KW - High entropy alloy KW - Machining KW - Ultrasonic machining PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512958 DO - https://doi.org/10.1088/1757-899X/882/1/012016 VL - 882 IS - 012016 SP - 1 EP - 11 PB - Institute of Physics CY - London AN - OPUS4-51295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scharf-Wildenhain, R. T1 - Wire Arc Additive Manufacturing (WAAM) mit hochfesten Feinkornbaustählen N2 - Die additive Verarbeitung hochfester Feinkornbaustähle mittels Wire Arc Additive Manufacturing (WAAM) ist ein komplexes, aber zugleich auch effizientes Verfahren, bei dem Werkstoff, Bauteilgeometrie und Schweißprozess gezielt aufeinander abgestimmt sein müssen. Ziel dieser Studie war es, einen Zusammenhang zwischen den Prozessparametern und der generierten Schichtgeometrie zu ermitteln. Dazu wurden definierte Referenzkörper mit einem robotergestützten Schweißsystem additiv gefertigt und hinsichtlich Schichthöhe, Wandstärke und Mikrostruktur analysiert. Fokus der Untersuchung waren sowohl konventionelle als auch für die WAAM-Fertigung speziell entwickelte hochfeste Schweißzusatzwerkstoffe. Die geometrischen Eigenschaften additiv gefertigter Bauteile lassen sich insbesondere durch die Faktoren Drahtvorschubgeschwindigkeit und Schweißgeschwindigkeit gezielt einstellen. Jedoch können diese Parameter nicht beliebig variiert werden, auch aufgrund der rheologischen Eigenschaften der Zusatzwerkstoffe. Zu hohe Streckenenergien führen zu lokalen Überhitzungen und Fehlstellen in der generierten Schicht. Undefinierte Fließ- und Erstarrungsvorgänge im überhitzten Bereich erschweren die maßhaltige Fertigung. Deshalb wird bei speziellen WAAM-Schweißdrähten das Fließverhalten gezielt modifiziert, sodass es über einen größeren Temperaturbereich hinweg konstant ist. Erst die Kenntnis über die komplexen Zusammenhänge zwischen den Prozessparametern und der Bauteilgeometrie ermöglicht die Erzeugung exakter Schichtmodelle für die additive Fertigung. Dies bildet die Grundlage für die Bearbeitung weiterer Fragestellungen auf dem Gebiet der additiven Fertigung mit hochfesten Zusatzwerkstoffen und insbesondere deren Anwendung in modernen hochfesten Bauteilen. T2 - 41. Assistentenseminar Fügetechnik CY - Magdeburg, Germany DA - 03.09.2020 KW - Additiver Fertigung KW - MSG-Schweißen KW - Eigenspannungen KW - Hochfester Stahl KW - Kaltrisssicherheit PY - 2020 AN - OPUS4-56690 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Komann, Steffen T1 - Transportbehälter für Klasse 7 - Ein Überblick N2 - Die Präsentation gibt einen Überblick über die Tranportbehälter der Klasse 7. Behandelt werden neben der Versandstückklassifikation auch die Anforderungen an diese Verpackungen gemäß der gefahrgutrechtlichen Vorschriften. T2 - 30. Münchner Gefahrguttage CY - Online meeting DA - 20.07.2020 KW - Gefahrgutrecht KW - Transportbehälter KW - Radioaktives Material KW - Zulassungspflichtige Versandstücke PY - 2020 AN - OPUS4-51104 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Welter, T. A1 - Müller, Ralf A1 - Deubener, J. A1 - Marzok, Ulrich A1 - Reinsch, Stefan T1 - Hydrogen Permeation Through Glass N2 - Physical storage of gaseous hydrogen under high-pressure in glassy micro-containers such as spheres and capillaries is a promising concept for enhancing safety and the volumetric capacity of mobile hydrogen storage systems. As very low permeation through the container wall is required for storage of compressed hydrogen, development of glasses of minimal hydrogen permeability is needed. For this purpose, one has to understand better the dependence of hydrogen permeability on glass structure. The paper points out that minimizing the accessible free volume is as one strategy to minimize hydrogen permeability. Based on previously measured and comprehensive literature data, it is shown that permeation is independently controlled by ionic porosity and network modifier content. Thus, ionic porosity in modified and fully polymerized networks can be decreased equally to the lowest hydrogen permeability among the glasses under study. Applying this concept, a drop of up to 30,000 with respect to the permeation of hydrogen molecules through silica glass is attainable. KW - Ionic porosity KW - hydrogen storage KW - Glass KW - Permeability KW - Solubility KW - Diffusivity PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-513927 DO - https://doi.org/10.3389/fmats.2019.00342 VL - 6 SP - Article 342 AN - OPUS4-51392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heuser, Lina T1 - Silver - alkali borate glass pastes N2 - Network modifier ions can decisively influence properties and structure of low melting alkali-zinc-borate glasses and thus cause complex effects on the liquid phase sintering of silver-glass metallization pastes. This effect was studied for X2O-ZnO-B2O3 (X = Li, Na, Rb) glasses for silver-glass metallization pastes. Viscosity and the glass transition temperature, Tg, were measured with rotational viscometry and dilatometry. Dried model pastes with 30 vol% LZB, NZB or RZB glass were prepared for sintering studies by means of heating microscopy measuring the silhouette area shrinkage of uniaxially pressed powder compacts during heating at 5 K/min. For comparison, the silhouette area shrinkage of pure glass and silver powder compacts were determined. Glass-silver wetting was investigated during heating of bulk glass cylinders placed on silver substrates. Glass RZB turned out to have the lowest viscosity among the glasses under study. Its glass transformation temperature, Tg, was found at 444 °C and it caused the lowest sintering onset for its glass and paste powder compacts. Slightly increased values of Tg were found for NZB and LZB (468 °C and 466 °C, respectively) and a slightly retarded sintering was found for both paste powder compacts. These results indicate that liquid phase sintering of silver-glass pastes under air atmosphere is mainly influenced by glass viscosity. T2 - GLASS MEETING 2020 CY - Online meeting DA - 07.12.2020 KW - Silver-glass metallization paste KW - Sintering KW - Alkali ions KW - Viscosity KW - Silver precipitates PY - 2020 AN - OPUS4-52871 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winckelmann, Alexander T1 - Next level lithium isotope analysis by atomic absorption spectrometry in combination with machine learning N2 - An alternative method for lithium isotope amount ratio analysis is proposed by combining atomic absorption spectrometry with spectra data analysis by machine leaning. It is based on the well-known isotope shift of around 15 pm for the electronic transition at wavelength 670.7845 nm which can be measured by a high-resolution continuum source atomic absorption spectrometer (HR-CS-AAS). For isotope amount ratio analysis, a scalable three boosting machine learning algorithm (XGBoost) was employed and calibrated with a set of samples with a 6Li isotope amount fraction ranging from 99% to 6%. The absolute Li isotope amount fractions of these calibration samples were previously measured by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) and used as ab-initio data for the machine learning algorithm. Validation of the machine leaning model was performed with two standard reference materials (LSVEC and IRMM-016). The procedure was employed for the isotope amount ratio determination of a set of stock chemicals (Li2CO3, LiNO3, LiCl, LiOH, and LiF) as well as a BAM candidate LiMNC cathode reference material. Achieved uncertainties are one order of magnitude higher than those obtained by MC-ICP-MS. This precision and accuracy is nonetheless sufficient to resolve natural occurring variations in Lithium isotope ratios. Also, the LiMNC material was analyzed by HR-CS-AAS with and without matrix purification. The results are comparable within statistical error. T2 - Make and Measure 2020 CY - Online Meeting DA - 15.10.2020 KW - Lithium batteries KW - HR-CS-AAS KW - Machine learning KW - Isotope analysis KW - Spectrometry PY - 2020 AN - OPUS4-51541 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Widjaja, Martinus Putra T1 - Sample Performance Chart (SPC) for displaying the results from a multiscale model N2 - The stacking sequence of a real scale type IV pressure vessels has been found. Feasibility study of a multiscale model has been carried out by modifying the original stacking sequence. All of the results were displayed in a Sample Performance Chart (SPC), where different burst pressure in terms of mean and scatter had been found. T2 - Consortium Meeting FiBreMoD CY - Valence, France DA - 17.02.2020 KW - Fibre break KW - Multiscale model KW - Reduced volume method KW - Sample performance chart KW - Type IV pressure vessels PY - 2020 AN - OPUS4-50563 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kratzig, A. A1 - Le, Quynh Hoa A1 - Bettge, Dirk A1 - Menneken, M. A1 - Bäßler, Ralph T1 - Early Stage of Corrosion Formation on Pipeline Steel X70 Under Oxyfuel Atmosphere at Low Temperature N2 - The early stage of corrosion formation on X70 pipeline steel under oxyfuel atmosphere was investigated by applying a simulated gas mixture (CO2 containing 6700 ppmv O2, 100 ppmv NO2, 70 ppmv SO2 and 50 ppmv H2O) for 15 h at 278 K and ambient pressure. Short-term tests (6 h) revealed that the corrosion starts as local spots related to grinding marks progressing by time and moisture until a closed layer was formed. Acid droplets (pH 1.5), generated in the gas atmosphere, containing a mixture of H2SO4 and HNO3, were identified as corrosion starters. After 15 h of exposure, corrosion products were mainly X-ray amorphous and only partially crystalline. In-situ energy-dispersive X-ray diffraction (EDXRD) results showed that the crystalline fractions consist primarily of water-bearing iron sulfates. Applying Raman spectroscopy, water-bearing iron nitrates were detected as subordinated phases. Supplementary long-term tests exhibited a significant increase in the crystalline fraction and formation of additional water-bearing iron sulfates. All phases of the corrosion layer were intergrown in a nanocrystalline network. In addition, numerous globular structures have been detected above the corrosion layer, which were identified as hydrated iron sulphate and hematite. As a type of corrosion, shallow pit formation was identified, and the corrosion rate was about 0.1 mma−1. In addition to in-situ EDXRD, SEM/EDS, TEM, Raman spectroscopy and interferometry were used to chemically and microstructurally analyze the corrosion products. KW - Corrosion KW - CCUS KW - In-situ ED-XRD KW - CO2 pipeline transport KW - Oxyfuel KW - Carbon steel KW - Impurities PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506303 DO - https://doi.org/10.3390/pr8040421 SN - 2227-9717 VL - 8 IS - 4 SP - 421-1 EP - 421-19 PB - MDPI CY - Basel AN - OPUS4-50630 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Aristia, Gabriela T1 - Polyaniline/Silicon Dioxide Composite-Based Coating for Corrosion Protection in Geothermal Systems N2 - Geothermal energy is one of the cleanest renewable alternatives to reduce the dependency on fossil fuel [1, 2]. Despite its promising future, its implementation faces various challenges, one of them being corrosion processes. To implement this energy, hot fluids are pumped from a geothermal well. These hot fluids originate from deep within the earth, so consist of different ionic species and gases in a wide range of temperatures, which lead to their corrosive nature. In terms of geothermal energy resources, Indonesia is at the forefront, with the highest preserved geothermal energy in the world of about 29 GWe and 312 potential geothermal locations [3]. Geothermal wells in Sibayak (North Sumatera), Indonesia, belong to young stratovolcanoes and have operating temperatures varying from 36 °C at the near ground surface to 310 °C at the bottom of the well, which is liquid-dominated with acidic and saline properties [4, 5]. Therefore, this geothermal fluid creates an aggressive environment that is conducive to corrosion of the powerplant infrastructure. Parts of the geothermal powerplant infrastructure, such as pipelines and heat exchangers, are commonly made of metals, e.g. carbon steel and stainless steel. Consequently, they may undergo corrosion and scaling when exposed to the geothermal fluid, especially for carbon steel. To ensure the safety and longevity of a geothermal powerplant, the infrastructure is constructed of expensive corrosion resistant alloys [6–10], e.g., titanium and Ni-Cr based alloys, or carbon steel which needs to be protected by coatings or inhibitors. To address the corrosion of carbon steel in the geothermal environment, artificial geothermal water was used to simulate a geothermal well in Sibayak, Indonesia, with pH 4 and a saline composition of 1,500 mg/l Cl-, 20 mg/l SO42-, 15 mg/l HCO3-, 200 mg/l Ca2+, 250 mg/l K+, and 600 mg/l Na+. Carbon steel underwent the most severe corrosion at 150°C in an oxygen-containing solution with a corrosion rate of 0.34 mm/year, which is approximately ten times higher than that in the absence of dissolved oxygen. In all conditions, pitting corrosion was observed, which necessitate a protection strategy on carbon steel. In order to promote a cost effective and locally available option, this work focused on an easily applicable coating which utilized local resources. Toward developing such protective coating based on the locally available resources in Indonesia which can yield good corrosion resistance and thermal stability in geothermal environment, two additional components, i.e. polyaniline (PANI) and silicon dioxide, were used to modify an alkyd-based commercial coating. The selection of the alkyd-based coating as a matrix focused on the industrial convenience basis, where the coating application procedure should be simple and easy to apply within reasonable costs. The alkyd-based coating underwent severe blistering when exposed to the artificial geothermal water at 70 and 150°C due to the reaction between CaCO3 (as one of its components) and the artificial geothermal water, as well as a possible alkyd hydrolysis in the initial stage of exposure. In the oxygen-free solution, the degradation was controlled by chemical and thermal reactions, whereas in the aerated condition, oxidization at the coating surface further accelerated polymer degradation. PANI was chosen as one of the anticorrosion pigments which was widely developed over the past decades. To investigate the interaction between PANI and the artificial geothermal water, PANI film was electrochemically deposited on the carbon steel surface and exposed to the artificial geothermal water. Electrochemically synthesized oxalate-doped PANI was protective against corrosion of carbon steel in artificial geothermal water at room temperature. The mechanism involved an exchange of electroactive species within the coating layer, as confirmed by electrochemical impedance spectra. Interaction of ionic species, such as Cl-, Na+, Ca2+ from the artificial geothermal water, with the outer layer of PANI is suggested both at 25°C and 150°C, based on the EDX spectra of the coating surface after exposure to the artificial geothermal water. Thus, the protection mechanism of PANI is not solely based on the physical barrier layer properties, but rather associated with the redox mediated properties of PANI, which selectively allow ionic species intrusion from the electrolyte into the PANI layer. Although PANI is a promising candidate as an anticorrosion coating, its morphological characterization reveals that electrochemically deposited PANI is not stable for an application at 150°C. Therefore, another approach was used to promote better protective behavior of PANI by dispersing chemically synthesized PANI in the alkyd-based coating. To enhance the thermal stability of the coating, silicon dioxide (SiO2) was added, which was able to prolong the sustainability of coated metals until 28 days compared to the unmodified alkyd-based coating, which underwent a change in color to brown/orange only within 7 days of exposure. This improvement might be associated with the role of SiO2 to proportionate the thermal expansion coefficient of the coating system to be compatible with that of carbon steel. Although the coating is thermally enhanced, the electrolyte might still intrude through the coating resulting in the change of coating color after 28 days of exposure in the artificial geothermal water. When PANI was added, the coating system provided an active corrosion protection on the carbon steel surface. The chemical and morphological characterization of the PANI-alkyd and SiO2-alkyd coating system showed that coatings were improved, and no blisters were observed, albeit the degradation continued. Based on the results of exposure tests, the combined coating system was further investigated. The combinational coating of PANI/SiO2-alkyd was used with 2 wt% of PANI and 15 wt% of SiO2. Electrochemical tests indicated cathodic protection at 150°C, as the Ecorr of PANI/SiO2 remained approximately 400 mV lower than the carbon steel potential. The impedance spectra of the combinational coating of PANI/SiO2 showed a continuous decrease in the absolute impedance value over time. A significant decrease was observed within one day of exposure, followed by a slow gradual decrease, which might be associated with water absorption in the coating. FTIR spectra revealed that several peaks associated with the organic portion of the coatings were reduced after the specimens were exposed for 6 months. However, the absorption peaks related to the inorganic portion of the coatings remained stable until 6 months. Morphological characterization of the combinational coating of PANI/SiO2 showed that there were no blisters or significant discoloration of coatings after long-term exposure for 6 months in artificial geothermal water at 150°C, indicating that the chemical degradation does not significantly affect the functionality of the coating. This clearly shows the durability of PANI/SiO2 coating in the geothermal condition, suggesting that this coating can be used for such geothermal application. However, further testing of this coating should be conducted in a real geothermal environment on-site to ensure safety and viability. KW - Geothermal KW - Corrosion KW - Coating KW - Polyaniline KW - Electrochemical impedance spectroscopy PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:188-refubium-26704-6 UR - https://refubium.fu-berlin.de/handle/fub188/26704 DO - https://doi.org/10.17169/refubium-26461 SP - 1 EP - 175 CY - Berlin AN - OPUS4-51281 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bäßler, Ralph A1 - Aristia, Gabriela T1 - Geothermie aus dem Vulkan – sicher und wirtschaftlich N2 - Indonesien gilt aufgrund seiner vielen Vulkane als einer der Hotspots für Geothermie. Doch Salz und Hitze setzen den Geothermie‐Anlagen zu und gefährden ihre Sicherheit und Wirtschaftlichkeit. Ein Team an der BAM hat günstigen, lokal verfügbaren Baustahl jetzt so beschichtet, dass ein nachhaltiger und sicherer Betrieb der Geothermie‐Kraftwerke möglich ist ‐ auch unter Extrembedingungen. Das BAM‐Team will das Beschichtungssystem nun den Anwendern in Indonesien zur Verfügung stellen, damit es unter Realbedingungen in einem Geothermie‐Kraftwerk getestet werden kann. Der Schutz vor Korrosion ist mitentscheidend, weil sie die Lebensdauer dieser Kraftwerke bestimmt. Unsere Arbeit könnte die Effizienz der Energieproduktion mit Geothermie wesentlich verbessern. KW - Geothermie KW - Korrosion PY - 2020 DO - https://doi.org/10.1002/maco.202070086 SN - 1521-4176 SN - 0947-5117 VL - 71 IS - 8 SP - 1 EP - 2 PB - WILEY‐VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-51074 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Anita T1 - Transport von defekten Lithiumbatterien: Umsetzungspraxis der neuen Rechtsvorschriften, Wo besteht Forschungsbedarf? N2 - Transport von defekten Lithiumbatterien - die BAM setzt die Vorschriften des internationalen Gefahrguttransportrechts für defekte Lithiumbatterien um. Um die Kompetenz hierfür sicherzustellen, bedarf es eigener Forschungstätigkeit. Auch im zuständigen UN Gremium werden Untersuchungen durchgeführt, an denen die BAM beteiligt ist. T2 - Fachkonferenz Lithiumbatterien CY - Göttingen, Germany DA - 22.01.2020 KW - Lithiumbatterien KW - Gefahrguttransport KW - ADR PY - 2020 AN - OPUS4-50806 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eberwein, Robert T1 - Untersuchung der Gefährdung von Personen und Bauwerken in Folge des Versagens von LNG-Kraftstoffspeichern für Fahrzeuge in Tunneln N2 - Der Markt von LNG als Transportgut und als Kraftstoff ist seit Jahrzehnten kontinuierlich am Wachsen, wobei das Hauptanwendungsgebiet im Schiffsverkehr lag. LNG ist verflüssigtes Erdgas mit Hauptbestandteil Methan, das neben fossilen, aus erneuerbaren Quellen, wie synthetischen Methan oder Biogas, gewonnen werden kann. LNG hat als Kraftstoff sehr gute Eigenschaften dessen Potenzial als alternativer Kraftstoff zu Diesel im Schwerlast- und Fernverkehr gesehen wird. Dabei weist LNG gegenüber Diesel geringere Emissionen von CO2, Feinstaub, Stickoxiden und Lärm auf und hat gegenüber anderen erneuerbaren Energiespeichern wie CNG, Elektrobatterien oder Wasserstoff die höchste volumetrische und zweitgrößte gravimetrische Energiedichte. Neben seinen Vorteilen zu anderen erneuerbaren Energieträgern birgt LNG durch seine sehr niedrige Temperatur von bis zu 160°C und seiner Brennbarkeit aber auch neue Gefahren für Personen und Infrastrukturen. Zur Bewertung von Gefahren und zur späteren Durchführung von Risikobewertungen bedarf es Methoden und Modellen deren Untersuchung Ziel des Forschungsprojekts war. Schwerpunkt der Untersuchung stellt die Freisetzung von LNG in Tunnel, mit sich anschließender Stoffausbreitung und verzögerter Zündung des Kraftstoff-Luftgemisches dar. Unfallszenarien mit Brandereignissen in Tunnel haben gezeigt, dass diese meist mit hohen Personen, Bauwerks und volkswirtschaftlichen Schäden verbunden sind. Des Weiteren zeigten Untersuchungen das von Gasexplosionen in Umschließungen wie sie ein Tunnel darstellt, mehr Gefahren ausgehen als von Gasexplosionen im Freifeld. Im Vortrag werden die untersuchten Modelle und die aus dem Projekt gewonnenen Erkenntnisse für die Stoffausbreitung und Verbrennung der Gasphase von LNG in Umschließungen vorgestellt. T2 - Abteilungs-Vortragsseminar-Doktoranden CY - BAM Berlin, Germany DA - 08.12.2020 KW - LNG KW - Erdgas KW - Störfall KW - CFD KW - Schwergas PY - 2020 AN - OPUS4-51959 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mair, Georg W. T1 - BAM - Bundesanstalt für Materialforschung und -prüfung: Hydrogen - Safety in Technology and Chemistry N2 - The presentation starts with some key figures about BAM. Then it introduces BAM's competence centre H2Safety@BAM and shows aspects of special competence of the centre. It closes with information about the engagement of BAM in European research projects on hydrogen and a reference to our bilingual paper about our hydrogen strategy. T2 - 27th Hydrogen Europe Research General Assembly CY - Online meeting DA - 02.07.2020 KW - Material properties and compatibility KW - Component testing KW - Safety assessment KW - Approval KW - Sensors KW - Inspection KW - Gas behaviour KW - Safe handling PY - 2020 AN - OPUS4-53155 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holtappels, Kai T1 - Hydrogen - Trust through safety N2 - In den Virtual Talks der DECHEMA wurden allgemeine Aspekte der Sicherheit und Akzeptanz von Wasserstofftechnologien vorgestellt. Wie kann Vertrauen in neue Technologien geschaffen werden, wenn Unfälle aus der Vergangenheit zu Mythen und Märchen führten? Der Vortrag räumt mit allgemeinen Vorurteilen auf und zeigt, dass der Umgang mit Wasserstoff weder unsicherer, noch sicherer ist als der Umgang mit anderen Brenngasen. Basis für den sicheren Umgang mit Wasserstoff ist immer eine Risikoanalyse. N2 - In the DECHEMA Virtual Talks, general aspects of the safety and acceptance of hydrogen technologies were presented. How can trust in new technologies be built when past accidents led to myths and fairy tales? The presentation does away with general prejudices and shows that handling hydrogen is neither more unsafe nor safer than handling other fuel gases. The basis for the safe handling of hydrogen is always a risk analysis. T2 - DECHEMA Virtual Talks CY - Online meeting DA - 23.11.2020 KW - Hydrogen KW - Wasserstoff KW - Safety KW - Sicherer Umgang KW - Sicherheit PY - 2020 AN - OPUS4-52082 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rhode, Michael A1 - Richter, Tim A1 - Mayr, P. A1 - Nitsche, A. A1 - Mente, Tobias A1 - Böllinghaus, Thomas T1 - Hydrogen diffusion in creep-resistant 9% Cr P91 multi-layer weld metal N2 - Welded components of P91 9% Cr steel demand for careful welding fabrication with necessary post weld heat treatment (PWHT). Before the PWHT, a hydrogen removal heat treatment is necessary for avoidance of hydrogen assisted cracking (HAC). In this context, the microstructure and temperature-dependent hydrogen diffusion is important, and reliable diffusion coefficients of P91 weld metal are rare. For that reason, the diffusion behavior of P91 multi-layer weld metal was investigated for as-welded (AW) and PWHT condition by electrochemical permeation experiments at room temperature and carrier gas hot extraction (CGHE) from 100 to 400 °C. Hydrogen diffusion coefficients were calculated, and the corresponding hydrogen concentration was measured. It was ascertained that both heat treatment conditions show significant differences. At room temperature the AW condition showed significant hydrogen trapping expressed by to seven times lower diffusion coefficients. A preferred diffusion direction was found in perpendicular direction expressed by high permeability. The CGHE experiments revealed lower diffusion coefficients for the AW condition up to 400 °C. In this context, a hydrogen concentration of approximately 21 ml/100 g was still trapped at 100 °C. For that reason, a certain HAC susceptibility of as-welded P91 weld metal cannot be excluded, and hydrogen removal should be done before PWHT. KW - Creep resisting materials KW - Diffusion KW - Hydrogen KW - Weld metal KW - Post weld heat treatment KW - Microstructure PY - 2020 DO - https://doi.org/10.1007/s40194-019-00828-8 SN - 0043-2288 VL - 64 IS - 2 SP - 267 EP - 281 PB - Springer AN - OPUS4-50471 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis T1 - Wasserstoffsicherheitsfragen - Sicherheitstechnische Kenngrößen von Wasserstoff und Gemischen von Wasserstoff mit Erdgas N2 - Wasserstoff unterscheidet sich hinsichtlich der sicherheitstechnischen Eigenschaften von anderen brennbaren Gassen, v.a. durch die sehr niedrige Mindestzündenergie und die sehr hohe Flammengeschwindigkeit. Durch Beimischung von Wasserstoff zum Erdgas ändern sich die sicherheitstechnischen Eigenschaften zum Teil in kritischer Richtung. Bis zu einem Wasserstoffanteil von 10 Mol-% im Erdgas ist aber keine wesentliche Anpassung der Maßnahmen für den Explosionsschutz erforderlich. Synthesgas ist ein weiteres Wasserstoffgemisch das in Zukunft vermutlich zunehmend relevant sein wird. Die beiden Komponenten Wasserstoff und Kohlenmonoxid haben zwar in mancher Hinsicht ähnliche sicherheitstechnische Eigenschaften unterscheiden sich aber auch sehr stark bzgl. der Mindestzündenergie und der Flammengeschwindigkeit. T2 - 9. HYPOS-Dialog: Grüner Wasserstoff, aber sicher! - Sicherheitsaspekte im Umgang mit Wasserstoff CY - Magdeburg, Germany DA - 11.09.2020 KW - Explosionsschutz KW - Zündenergie KW - Explosionsgrenzen KW - Zündquellen KW - Synthesegas PY - 2020 AN - OPUS4-51264 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis T1 - Safety Related Properties of Hydrogen Mixtures - Laboratory Tests N2 - Wasserstoff unterscheidet sich hinsichtlich der sicherheitstechnischen Eigenschaften von anderen brennbaren Gassen, v.a. durch die sehr niedrige Mindestzündenergie und die sehr hohe Flammengeschwindigkeit. In der Praxis treten Wasserstoffgemische z.B. durch Einspeisung von Wasserstoff in das Erdgasnetz, bei der Herstellung von Synthesegas (CO, H2) und in Biogasanlagen auf. Die sicherheitstechnischen Eigenschaften von Wasserstoffgemischen wurden experimentell untersucht und werden vorgestellt. Darüber hinaus wurde die Genauigkeit von Berechnungsmethoden für sicherheitstechnische Eigenschaften von Wasserstoffgemischen untersucht. N2 - Hydrogen differs from most other flammable gases regarding the safety related properties. Mainly the minimum ignition energy (MIE) is particularly low and the burning velocity is particularly high. Hydrogen mixtures are formed in different hydrogen applications, for example if hydrogen is added to the existing natural gas grid, if synthetic gas (mixture of CO and H2) is produced or in biogas plants. Safety related properties of hydrogen mixtures were determined experimentally and are presented in this presentation. Moreover the accuracy of estimation methods for safety related properties of hydrogen mixtures is evaluated.” T2 - Center for Hydrogen Safety 2020 European Conference CY - Online meeting DA - 20.10.2020 KW - Explosion Protection KW - Explosion Limits KW - Minimum Ignition Energy KW - Ignition Source KW - Synthetic Gas PY - 2020 AN - OPUS4-51530 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Butz, Adam T1 - Detection and prediction of high temperature fatigue crack growth around notches in polycrystalline nickel base alloy N2 - Im Rahmen eines Vorhabens wurden Methoden zur Reduktion des Versuchsaufwandes bei der Modellerstellung für LCF-Lebensdauervorhersage untersucht. Einige dieser Methoden sind hier kurz vorgestellt. N2 - Methods for reducing the experimental effort necessary for the development of LCF life time prediction models were investigated. Some of these methods are briefly presented here. T2 - 4th International Symposium for Fatigue Design and Material Defects CY - Online meeting DA - 26.05.2020 KW - LCF KW - Mechanistic Modelling KW - Fatigue KW - Data Fusion PY - 2020 AN - OPUS4-50904 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Orellana Pérez, Teresa T1 - Die Wasserstoffstrategie der BAM; Kompetenzzentrum H 2 safety@bam N2 - Das Thema Wasserstoff ist an der BAM seit mehr als hundert Jahren aktuell und steht auch gegenwärtig im Zentrum zahlreicher Forschungs- und Kooperationsaktivitäten. Mit der aktuellen Wasserstoff-Strategie der BAM werden wichtige Voraussetzungen dafür geschaffen, dass der Markthochlauf gelingt und die technische Sicherheit und Überwachung der Infrastrukturen und Anlagen gewährleistet ist – von der Erzeugung, über den Transport bis zur Speicherung und Bereitstellung von Wasserstoff als Energieträger der Zukunft. T2 - 1st Digital AK PostDocs Meeting CY - Online meeting DA - 01.10.2020 KW - Kompetenzzentrum H2Safety@BAM KW - Wasserstoff KW - Wasserstoffstrategie PY - 2020 AN - OPUS4-51371 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis T1 - Explosion Protection for Hydrogen Applications N2 - In the this lecture the safety related properties of hydrogen compared to other fuel gases and the explosion protection measures of avoiding flammable mixtures, avoiding ignition sources and mitigating the consequences of explosions are presented. T2 - Guest Lecture at the University of Birmingham CY - Online meeting DA - 19.10.2020 KW - New energy carriers KW - Explosion limits KW - Ignition energy KW - Ignition source KW - Renewable energy PY - 2020 AN - OPUS4-51531 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph T1 - Entwicklung einer Prüfmethode zur Bewertung der Materialbeständigkeit von Bauteilen in Mitteldestillatanwendungen N2 - Im DGMK-Projekt 780 wurde eine forcierte Prüfmethode entwickelt zur Bestimmung der Beständigkeit von metallenen Werkstoffen gegenüber Brennstoffen aus Mitteldestillaten und Gemischen aus Mitteldestillat und paraffinischen Kohlenwasserstoffen, die jeweils Fettsäuremethylester (FAME) als biogene Komponente enthalten. Bei der Prüfmethode werden Proben des Werkstoffes in einem speziellen Prüfmedien ausgelagert. Die Zusammensetzung von zwei Prüfmedien wurde im Vorhaben erarbeitet. Die Prüfmedien decken für den FAME-Anteil einen Bereich von bis zu 20 % (V/V) ab. Die Auslagerung kann bei geringem Aufwand unter Atmosphärendruck durchgeführt werden. Die Eignung einer Auswahl von metallenen Werkstoffen und Polymerwerkstoffen, die für Versorgungsanlagen für Mitteldestillat relevant sind, wurde durch Auslagerung in folgenden nicht gealterten Brennstoffen bestimmt: Heizöl EL schwefelarm (B0), Heizöl EL schwefelarm mit 20 % (V/V) FAME (B20), FAME (B100) und hydriertes Pflanzenöl (HVO). Die Temperatur bei der Auslagerung betrug 50 °C für die metallenen Werkstoffe und 40 °C und 70 °C für die Polymerwerkstoffe. Die Ergebnisse der Beständigkeitsbewertung wurden in Beständigkeitslisten zusammengefasst. Die mit dem B20 erhaltenen Werkstoffbeständigkeiten gelten generell für Gemische aus Heizöl EL schwefelarm und FAME mit einem FAME-Gehalt bis zu 20 % (V/V). Sie sind auch auf Gemische aus Dieselkraftstoff und FAME mit einem FAME-Gehalt bis 20 %(V/V) übertragbar. Die forcierte Prüfmethode kann insbesondere KMUs bei der Weiterentwicklung von bestehenden Produkten und der Entwicklung von neuen Produkten als ein kostengünstiger Schnelltest zur Überprüfung der Werkstoff- und Bauteilbeständigkeit gegenüber Mitteldestillaten mit hohem FAME-Anteil dienen. Sie kann für die Hersteller die Sicherheit erhöhen, dass Bauteile die Freigabeprüfungen der Bauaufsicht bestehen, wobei die Freigabe aber nur für Deutschland gültig ist. Die Erkenntnisse des Forschungsvorhabens können in eine harmonisierte Europäischen Norm für alternative Brenn- und Kraftstoffe einfließen. Diese ist für die Bauteilhersteller die Voraussetzung für die Erschließung des europäischen Marktes. T2 - Sitzung des DGMK-Fachausschusses "Brennstoffe" CY - Online Meeting DA - 22.09.2020 KW - Korrosion KW - Biobrennstoff KW - Heizöl KW - FAME PY - 2020 AN - OPUS4-51300 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph T1 - Deposition of Brine Components on Materials in Geothermal Conditions T1 - ОСАЖДЕНИЕ КОМПОНЕНТОВ ГЕОТЕРМИЧЕСКИХ ВОД НА МАТЕРИАЛЫ В ГЕОТЕРМАЛЬНЫХ УСЛОВИЯХ 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 in many cases extreme in terms of corrosion due to the chemical composition of hydrothermal fluids and temperatures. Therefore, materials selection based on preliminary material qualification is essential to guarantee a secure and reliable operation of the facilities. During operation of a geothermal research facility in Groß Schönebeck copper and lead effects have been found downhole. Occurring mechanisms and measures to prevent precipitation or scaling needed to be investigated as well as potential influences of such precipitates on corrosion resistance of metallic materials used for equipment. This contribution deals with the evaluation of the corrosion behavior of carbon steel and corrosion resistant alloys in copper and/or lead containing artificial geothermal water, simulating the conditions in the Northern German Basin. The behavior of these materials in an artificial geothermal water obtained by electrochemical measurements and exposure tests are presented. While carbon steel exhibits precipitation and deposition, higher alloyed material shows different response to such species and a higher resistance in saline geothermal water. Basing on these results the suitability of the investigated corrosion resistant alloy is given for use in such conditions, whereas carbon steel creates difficulties due to its susceptibility to Cu- and Pb-precipitation. N2 - Поскольку геотермальные скважины являются реальным источником энергии для замены поставок ископаемого топлива, было разработано множество технологий для использования преимуществ геотермальной энергии. Тем не менее, условия эксплуатации на геотермальных установках во многих случаях являются экстремальными с точки зрения коррозии из-за химического состава гидротермальных жидкостей и температур. Таким образом, выбор материалов на основе предварительной квалификации имеет важное значение для обеспечения безопасной и надежной работы геотермальных объектов. Во время работы исследовательской установки в Грос Шёнебек (Groß Schönebeck) в скважине было обнаружено воздействие меди и свинца. Необходимо изучить возникшие механизмы и меры для предотвращения депозиции или образования коррозии, а также потенциальное влияние таких осаждений на коррозионную стойкость металлов, используемых для оборудования. Этот доклад посвящен оценке коррозионного поведения углеродистой стали и коррозионно-стойких сплавов в геотермальной воде, содержащей медь и / или свинец, моделирующей условия в Северогерманском бассейне (North German basin). Представлено поведение этих металлических материалов в геотермальной воде, полученной путем электрохимических измерений и испытаний на воздействие. В то время как углеродистая сталь демонстрирует коррозию и отложения, высоколегированный материал демонстрирует более высокую стойкость в соленой геотермальной воде. На основании этих результатов пригодность исследуемого коррозионно-стойкого сплава дана для использования в данных условиях, тогда как углеродистая сталь создает трудности из-за ее восприимчивости к депозиции солей меди и свинца. T2 - ХV International Conference Problems of Corrosion and Corrosion Protection of Materials “CORROSION-2020” CY - Online meeting DA - 15.10.2020 KW - Copper KW - Lead KW - Corrosion KW - Steel KW - Geothermal PY - 2020 UR - http://www.ipm.lviv.ua/corrosion2020/ AN - OPUS4-51438 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph T1 - Metallic Materials for Geothermal Applications N2 - The aim of the work presented was the evaluation of corrosion resistance of various materials in geothermal Waters as a base to create a catalogue of suitable materials for applications in (not only) German geothermal power plants. Users shall be enabled to have a basis for designing such facilities. High alloyed corrosion resistant alloys are suitable and do not cause copper or lead deposition. They shall be chosen for future design of the piping system, either in massive or in cladded form, if crevices formation with non-metallic materials can be prevented! T2 - IFPEN-Workshop: Corrosion in Low-Carbon Energies CY - Online meeting DA - 03.11.2020 KW - Geothermal KW - Corrosion KW - Saline brine PY - 2020 AN - OPUS4-51511 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph T1 - Corrosive CO2-stream components, challenging for materials to be used in CC(U)S applications N2 - This contribution provides current findings regarding materials susceptibility for CCUS applications. Basing on results gathered in 2 German long-term projects (COORAL and CLUSTER) suitable materials are introduced as well as dominating impurities of the CO2 stream and corrosion mechanisms. Investigations cover the whole CCUS process chain and provide the following recommendations for certain parts. Commercially available carbon steels are suitable for compression and pipelines as long as moisture content and impurities are limited (water 50 to 100 ppmv, SO2 and NO2 ca. 100 ppmv). Corrosion rates increase with increasing water content (0.2 – 20 mm/a). Condensation of acids and therefore droplet formation is always possible, even at low water contents. A low SO2 content within the CO2-stream might be more important than a low water content. Cr13-steels showed a general susceptibility to shallow pitting and pitting. So, they seem to be not suitable for CCUS applications. Low alloyed steels showed better corrosion behavior (predictable uniform corrosion). For direct contact with saline aquifer fluids only high alloyed steels shall be used. T2 - WCO Webinar on the occasion of Corrosion Awareness Day - Corrosion and Low-Carbon Energies CY - Frankfurt, Germany DA - 24.04.2020 KW - CO2-corrosion KW - CCUS KW - Pipeline KW - Carbon Capture PY - 2020 AN - OPUS4-50699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Ackermann, H. A1 - Pötzsch, Sina A1 - Weltschev, Margit A1 - Bäßler, Ralph A1 - Plum, W. T1 - Entwicklung einer Prüfmethode zur Bewertung der Materialbeständigkeit von Bauteilen in Mitteldestillatanwendungen N2 - Im Vorhaben wurde eine forcierte Prüfmethode zur Bestimmung der Beständigkeit von metallenen Werkstoffen gegenüber Brennstoffen aus Mitteldestillaten und Gemischen aus Mitteldestillat und paraffinischen Kohlenwasserstoffen, die jeweils Fettsäuremethylester (FAME) als biogene Komponente enthalten, entwickelt. Bei der Prüfmethode werden Prüfkörper des jeweiligen Werkstoffes in speziellen Prüfmedien ausgelagert. Die Zusammensetzung von zwei Prüfmedien wurde im Vorhaben erarbeitet. Diese Prüfmedien erfassen die Effekte der Alterung des FAME, die zu erwarten sind, wenn der Brennstoff länger als 2 Jahre im Feld lagert. Sie decken den Bereich bis 20 % (V/V) FAME-Anteil ab. Die Auslagerung kann bei geringem Aufwand unter Atmosphärendruck durchgeführt werden. Die Eignung einer Auswahl von metallenen Werkstoffen und Polymerwerkstoffen, die für Versorgungsanlagen für Mitteldestillat relevant sind, wurde durch Auslagerung in folgenden nicht gealterten Brennstoffen bestimmt: Heizöl EL schwefelarm (B0), Heizöl EL schwefelarm mit 20 % (V/V) FAME (B20), FAME (B100) und hydriertes Pflanzenöl (HVO). Die Werkstoffe wurden auch in einem 1 Jahr gealterten B20 und einem 8 Jahre gealtertem B10 ausgelagert. Die Temperatur bei der Auslagerung betrug 50 °C für die metallenen Werkstoffe und 40 °C und 70 °C für die Polymerwerkstoffe. Die Ergebnisse der Beständigkeitsbewertung wurden in Beständigkeitslisten zusammengefasst. Die mit B20 erhaltenen Bewertungen gelten generell für Gemische aus Heizöl EL schwefelarm und FAME mit einem FAME-Gehalt bis 20 % (V/V). Sie sind auch auf Gemische aus Dieselkraftstoff und FAME mit einem FAME-Gehalt bis 20 %(V/V) übertragbar. Die forcierte Prüfmethode kann insbesondere KMUs bei der Weiterentwicklung von bestehenden Produkten und der Entwicklung von neuen Produkten als ein kostengünstiger Schnelltest zur Überprüfung der Werkstoff- und Bauteilbeständigkeit gegenüber Mitteldestillaten mit hohem FAME-Anteil dienen. Sie kann für die Hersteller die Sicherheit erhöhen, dass Bauteile die Freigabeprüfungen der Bauaufsicht bestehen, wobei die Freigabe jedoch nur für Deutschland gültig ist. Die Erkenntnisse des Forschungsvorhabens können in eine harmonisierte Europäische Norm für alternative Brenn- und Kraftstoffe einfließen. Diese ist für die Bauteilhersteller die Voraussetzung für die Erschließung des europäischen Marktes.   N2 - Within this project, a forced test method was developed to determine the resistance of metallic materials to middle distillate fuels and mixtures of middle distillate and paraffinic hydrocarbons both with fatty acid methyl ester (FAME) as a biogenic component. In the method, specimens of the material are immersed in special test media. The compositions of two test media were developed within the project. These test media include the influence of aging of the FAME which is to be expected after a storage of the fuel exceeding 2 years in the field. They cover a range of up to 20 % (v/v) FAME content. The exposure test can be carried out at ambient pressure with little effort. Suitability of selected metallic and polymer materials relevant for middle distillate supply systems was determined by exposure to the following non-aged fuels: low-sulfur light fuel oil (B0), low-sulfur light fuel oil with 20 % (v/v) FAME (B20), FAME (B100) and hydrogenated vegetable oil (HVO). The materials were also exposed in the 1-year-aged B20 and 8-year-aged B10. Test temperature was 50 °C for metallic materials and 40 °C and 70 °C for polymers. Resulting materials resistances were summarized in resistance tables. Resistances obtained in B20 are valid for any mixture of low-sulfur light fuel oil and FAME containing up to 20 % (v/v) FAME. They are also transferable to mixtures of diesel and FAME having a FAME content of up to 20 % (v/v). This method with special test media is a cost-effective rapid test for checking resistance of materials to middle distillates having a high FAME content. It can support SMEs manufacturing components for supply systems in further development of existing and new products. It increases the manufacturers' certainty that components will pass approval tests of authorities. Results of this research project can be incorporated into a harmonized European standard for alternative fuels. This is the prerequisite for component manufacturers to access the European market. KW - Heizöl KW - FAME KW - Biobrennstoff PY - 2020 UR - https://dgmk.de/publikationen/entwicklung-einer-pruefmethode-zur-bewertung-der-materialbestaendigkeit-von-bauteilen-in-mitteldestillatanwendungen/ SN - 978-3-947716-14-2 SN - 0937-9762 SP - 1 EP - 153 PB - DGMK CY - Hamburg AN - OPUS4-51110 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völzke, Holger T1 - Research at BAM on Metal Seal Performance and Fuel Rod Integrity N2 - The presentation provides an update on preliminary results from research projects in the area of long term performance of metal seals and fuel rod integrity as safety relevant components of spent fuel transport and storage casks for spent nuclear fuel. T2 - Extended Storage Collaboration Program (ESCP) Winter Meeting 2020 CY - Online meeting DA - 09.11.2020 KW - Metal seal KW - Safety KW - Interim storage KW - Spent nuclear fuel KW - Fuel rod PY - 2020 AN - OPUS4-51615 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zaghdoudi, Maha A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Übersicht über laufende Untersuchungen zur Langzeitalterung von Elastomerdichtungen N2 - Eine Aufgabe des Fachbereichs 3.4 Sicherheit von Lagerbehältern der Bundesanstalt für Materialforschung und -prüfung (BAM) ist es, die Sicherheit von Behältern zur Lagerung von radioaktivem Abfall mit vernachlässigbarer Wärmeentwicklung zu bewerten. Da solche Behälter vor der Entsorgung transportiert und gelagert werden, ist während dieser Zeit ein sicherer Einschluss des radioaktiven Inhalts von größter Bedeutung. Zur Abdichtung dieser Behälter sind Elastomer-O-Ringe weit verbreitet. Um für solche, wie auch für viele andere Anwendungen, eine Voraussage über die Lebensdauer dieser Komponenten treffen zu können, ist es unerlässlich zu verstehen, welchen Einfluss der durch Alterung hervorgerufene Abbau auf Dauer auf die Elastomerdichtungen hat. In einem Langzeittest wurden drei Kautschukarten (EPDM und FKM, die für die Anwendung relevant sind, und HNBR als Vergleich) über mehrere Jahre untersucht. Dabei wurden die Veränderungen der mechanischen Eigenschaften (z. B. Härte und Bruchdehnung) bei vier verschiedenen Alterungstemperaturen (75 °C, 100 °C, 125 °C und 150 °C) sowie das Dichtungsverhalten betrachtet. Um den Einfluss von Vernetzung und Kettenspaltung auf die beobachteten Alterungseffekte zu bestimmen, wurden Messungen zur kontinuierlichen und intermittierenden Druckspannungsrelaxation durchgeführt. Dadurch konnten Erkenntnisse über Kinetik und Mechanismus der Abbaureaktionen gewonnen werden. Zur Einschätzung des Dichtungsverhaltens wurden Durckverformungsrest und Leckagerate gemessen. Die Ergebnisse zeigen, dass die O-Ringe unter statischen Bedingungen auch dann dicht halten, wenn die Werte für Druckverformungsrest, Druckspannungsrelaxation und mechanische Eigenschaften schon auf einen fortgeschrittenen Alterungsabbau hindeuten. Aus diesem Grund wurde ein modifizierter Dichtigkeitsversuch mit einer geringen und schnellen teilweisen Entlastung der Dichtung entwickelt, mit dessen Hilfe sich ein Lebensdauerkriterium bestimmen lässt, das eine Sicherheitsspanne für thermische Schrumpfung und Vibrationen beinhaltet. KW - Alterung KW - O-ring KW - Elastomer Dichtung PY - 2020 SN - 0176-1625 VL - 73 IS - 07-08 SP - 326 EP - 332 PB - Gupta CY - Ratingen AN - OPUS4-51207 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Goral, Milan A1 - Wolff, Dietmar T1 - Insights for lifetime predictions of O-ring seals from five-year long-term aging tests N2 - O-rings made of HNBR, EPDM and FKM were aged in the compressed and uncompressed state at 150 °C, 125 °C, 100 °C, 75 °C, 60 °C and 23 °C for aging times of up to five years. Hardness was measured and increased with aging time and temperature for HNBR and EPDM, but it remained practically constant for FKM. Indenter modulus measurements were performed on the lateral O-ring surface (that was free of DLO effects) to assess an influence of the compression during aging, but none was detected. The equilibrium compression set (CS) exhibited faster and stronger degradation than hardness and was used for lifetime predictions using the time-temperature superposition (TTS) principle. With an end-of-lifetime criterion of 70 % CS, lifetimes of 4.5 years, 50 years and 526 years at 75 °C were estimated for HNBR, EPDM and FKM, respectively. The activation energies derived from an Arrhenius plot of the shift factors from the TTS were 85 kJ/mol, 99 kJ/mol and 78 kJ/mol for HNBR, EPDM and FKM, respectively, revealing that a higher activation energy does not necessarily mean that the material has a higher lifetime at lower temperatures. Furthermore, the measured lifetime of EPDM O-rings at 100 °C (5 years) was compared to that predicted on the basis of the lifetime at 150 °C as well as 125 °C using the corresponding shift factors. The error of the prediction was only ± 4 %. However, this precise prediction could only be achieved using the five-year long-term aging data. When using only data from aging times up to 0.5 years and 2 years, the lifetime of EPDM O-rings at 100 °C was underestimated by 31 % and 22 %, respectively. KW - HNBR KW - EPDM KW - FKM KW - DLO KW - Hardness KW - Compression set KW - Rubber KW - Elastomer KW - Degradation PY - 2020 DO - https://doi.org/10.1016/j.polymdegradstab.2020.109278 VL - 179 SP - 109278 PB - Elsevier Ltd. AN - OPUS4-51060 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zaghdoudi, Maha A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Erroneous or Arrhenius: A Degradation Rate-Based Model for EPDM during Homogeneous Ageing N2 - To improve the predictive capability of long-term stress relaxation of elastomers during thermo-oxidative ageing, a method to separate reversible and irreversible processes was adopted. The separation is performed through the analysis of compression set after tempering. On the Basis of this separation, a numerical model for long-term stress relaxation during homogeneous ageing is proposed. The model consists of an additive contribution of physical and chemical relaxation. Computer simulations of compression stress relaxation were performed for long ageing times and the results were validated with the Arrhenius treatment, the kinetic study and the time-temperature superposition technique based on experimental data. For chemical relaxation, two decay functions are introduced each with an activation energy and a degradative process. The first process with the lower activation energy dominates at lower ageing times, while the second one with the higher activation energy at longer ageing times. A degradation-rate based model for the evolution of each process and ist contribution to the total system during homogeneous ageing is proposed. The main advantage of the model is the possibility to quickly validate the interpolation at lower temperatures within the range of slower chemical processes without forcing a straight-line extrapolation. KW - Kinetic study KW - Arrhenius KW - TTS KW - Modeling KW - Chemical processes KW - Stress relaxation PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512931 DO - https://doi.org/10.3390/polym12092152 SN - 2073-4360 VL - 12 IS - 9 SP - 1 EP - 21 AN - OPUS4-51293 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ziesche, R. A1 - Robinson, J. A1 - Kok, M. A1 - Markötter, Henning A1 - Kockelmann, W. A1 - Kardjilov, N. A1 - Manke, I. A1 - Brett, D. A1 - Shearing, P. T1 - Editors’ Choice—4D Neutron and X-ray Tomography Studies of High Energy Density Primary Batteries: Part I. Dynamic Studies of LiSOCl2 during Discharge N2 - The understanding of dynamic processes in Li-metal batteries is an important consideration to enable the full capacity of cells to be utilised. These processes, however, are generally not directly observable using X-ray techniques due to the low attenuation of Li; and are challenging to visualise using neutron imaging due to the low temporal resolution of the technique. In this work, complementary X-ray and neutron imaging are combined to track the dynamics of Li within a primary Li/SOCl2 cell. The temporal challenges posed by neutron imaging are overcome using the golden ratio imaging method which enables the identification of Li diffusion in operando. This combination of techniques has enabled an improved understanding of the processes which limit rate performance in Li/SOCl2 cells and may be applied beyond this chemistry to other Li-metal cells. KW - Nneutron imaging KW - X-ray imaging KW - Tomography KW - Primary Battery PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515802 DO - https://doi.org/10.1149/1945-7111/abbbbc SN - 1945-7111 VL - 13 IS - 167 SP - 130545 PB - IOP Publishing AN - OPUS4-51580 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sachse, René A1 - Pfüger, Mika A1 - Velasco-Vélez, Juan-Jesús A1 - Sahre, Mario A1 - Radnik, Jörg A1 - Bernicke, Michael A1 - Bernsmeier, Denis A1 - Hodoroaba, Vasile-Dan A1 - Krumrey, Michael A1 - Strasser, Peter A1 - Kraehnert, Ralph A1 - Hertwig, Andreas T1 - Assessing optical and electrical properties of highly active IrOx catalysts for the electrochemical oxygen evolution reaction via spectroscopic ellipsometry N2 - Efficient water electrolysis requires highly active electrodes. The activity of corresponding catalytic coatings strongly depends on material properties such as film thickness, crystallinity, electrical conductivity, and chemical surface speciation. Measuring these properties with high accuracy in vacuum-free and nondestructive methods facilitates the elucidation of structure−activity relationships in realistic environments. Here, we report a novel approach to analyze the optical and electrical properties of highly active oxygen evolution reaction (OER) catalysts via spectroscopic ellipsometry (SE). Using a series of differently calcined, mesoporous, templated iridium oxide films as an example, we assess the film thickness, porosity, electrical resistivity, electron concentration, electron mobility, and interband and intraband transition energies by modeling of the optical spectra. Independently performed analyses using scanning electron microscopy, energy-dispersive X-ray spectroscopy, ellipsometric porosimetry, X-ray reflectometry, and absorption spectroscopy indicate a high accuracy of the deduced material properties. A comparison of the derived analytical data from SE, resonant photoemission spectroscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy with activity measurements of the OER suggests that the intrinsic activity of iridium oxides scales with a shift of the Ir 5d t2g sub-level and an increase of p−d interband transition energies caused by a transition of μ1-OH to μ3-O species. KW - Spectroscopic ellipsometry KW - Electrocatalysis KW - Oxygen evolution reaction KW - Mesoporous iridium oxide films KW - Non-destructive ambient analysis KW - Intrinsic OER activity KW - Complementary methodology and metrology PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-516288 DO - https://doi.org/10.1021/acscatal.0c03800 SN - 2155-5435 VL - 10 IS - 23 SP - 14210 EP - 14223 PB - American Chemical Society AN - OPUS4-51628 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zaghdoudi, Maha A1 - Weber, Mike A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Numerical Modelling of Compression Stress Relaxation and Compression Set of Elastomer O-Ring During Aging N2 - Elastomer seals are used in many industrial applications due to their excellent mechanical properties at a wide range of temperatures. Their high versatility and recovery potential under several load conditions make them well suitable for the application in containers designed for transport, storage and/or disposal of radioactive materials. In containers for low and intermediate level radioactive waste, elastomer seals are used as barrier seals, and as auxiliary seals in storage and transportation casks (dual purpose casks) for heat generating radioactive waste, such as spent fuel and high-level waste. While a seal exchange at defined intervals is typical in many conventional applications, it is impossible or at least hard to perform when principles of minimization of radiation exposure have to be considered and prohibit an unnecessary cask handling. An extensive knowledge of the change of the elastomer’s properties during aging and the availability of reliable end-of-lifetime criteria to guarantee the permanent safe enclosure of the radioactive material is mandatory. As BAM is involved in most of the national cask licensing procedures and in the evaluation of cask-related long-term safety issues, great efforts have been already made and are still planned to scientifically support this task. Compression stress relaxation and compression set were identified as key indicators of elastomer long-term performance and quantitatively investigated in comprehensive test programs. Among other representative types of elastomers, specimens made from ethylene propylene diene rubber (EPDM) were tested before, during and after aging to capture the most important of their complex mechanical properties. In the presented study, exemplary results were used to simulate the compression stress relaxation and the compression set of elastomer O-rings during aging. Regarding the influence of temperature, the time-temperature superposition principle is applied in the relaxation analysis of elastomer O-rings. The proposed model is implemented in the commercial finite element software ABAQUS/Standard® [1] with a sequential temperature displacement coupling. Numerical results match the experimental compression stress relaxation measurements well. The prediction of compression set values after long-term aging shows a relatively good agreement with the experimental results. Nevertheless, all input parameters derived from the specimen tests, additional assumptions concerning boundary conditions and modeling strategy are discussed with regard to the identified slight discrepancies. The possibility to extend the finite element model to represent the O-ring seal’s ability to recover after a (fast) partial release is taken into account. T2 - ASME 2020 Pressure Vessels & Piping Conference (PVP2020) CY - Online meeting DA - 03.08.2020 KW - Compression Set KW - O-ring KW - Simulation KW - Sequential analysis KW - Ageing KW - stress relaxation PY - 2020 SN - 978-0-7918-8388-4 DO - https://doi.org/10.1115/PVP2020-21270 SP - PVP2020-21270 PB - ASME AN - OPUS4-51490 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg T1 - Photolytically and Thermally Initiated Destruction on the Stability of (Ultra)High Molecular Polyethylene N2 - THz and mid IR spectroscopy of high-molecular PE (HMW) and ultra high-molecular PE (UHMW) reveals modifications of the molecular structure. Characteristic absorption bands are changed if the two materials are exposed by γ-Co60 radiation up to 600 kGy and subsequently stored at an annealing temperature of 398 K until for 729 days. UHMW-PE and HMW-PE behave differently during the ageing process because of their molecular weight and inherent structure distinctions. The spectroscopic data offer characteristic absorption bands, which have been used to describe the complete ageing process in more detail. For instance, the integral absorption in the B1u THz-region can be used to describe quantitatively the reduction of crystallinity. The formation of trans vinylene unsaturation and the decay of vinyl during ageing can be observed in detail in the mid IR range. T2 - 9th International Workshop on Terahertz Technology and Applications CY - Kaiserslautern, Germany DA - 03.03.2020 KW - Degradation KW - MID IR Spectroscopy PY - 2020 AN - OPUS4-50555 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jaunich, Matthias A1 - Goral, Milan A1 - Wolff, Dietmar A1 - Völzke, Holger ED - Krüssenberg, A. T1 - Overview of metal seal tests performed at BAM and implications for extended interim storage N2 - The investigation of the long-term performance of sealing systems employed in containers of radioactive waste and spent nuclear fuel is one research focus area for division 3.4 \Safety of Storage Containers" at the Bundesanstalt für Materialforschung und -prüfung. The behaviour of metallic seals, which are employed in interim storage casks for spent nuclear fuel and high active waste, over time is of high importance for ensuring safe enclosure. Therefore, investigations on these systems were started at BAM to get a general understanding of the relevant processes. Our investigations comprise investigations on different parameters which influence the seal Performance and the main part is focussed on the time and temperature dependent behaviour. Our aim is to understand the longterm behaviour of the sealing systems for evaluation of their performance during possible extended interim storage and subsequent transportation. In this contribution an overview of the performed tests and their respective results is given. A focus lies on a comparison between seals with large torus diameter in comparison to small diameters. T2 - Safety of Extended Dry Storage of Spent Nuclear Fuel SEDS2020: International online-workshop CY - Online meeting DA - 03.06.2020 KW - Metal seal KW - Seal performance KW - Long-term investigation KW - Ageing PY - 2020 DO - https://doi.org/10.3139/124.200071 SN - 0932-3902 VL - 85 IS - 6 SP - 440 EP - 443 PB - Carl Hanser Verlag CY - München AN - OPUS4-51833 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Sophie T1 - Reaction sintering and sintering additives for cost-effective production of thermoelectric oxides N2 - Thermoelectric oxides attract much interest recently. Although their thermoelectric properties are inferior to non-oxides, they exhibit distinct advantages. Thermoelectric oxides are stable in air at higher temperatures, their raw materials are less toxic, and more abundant. To enhance attractivity of these materials for industrial applications, production costs need to be reduced. Conventionally, the legs of thermoelectric generators are sintered from green bodies of previously synthesized powder. Reaction-sintering is a fabrication method without a powder synthesis step, as the final phase is formed during the sintering from a raw material mixture. Moreover, the reduction of chemical potential during reaction-sintering is effective as an additional driving force for sintering. We show that reaction-sintering increases the densification of CaMnO3 (n-type, Sm doped). Consequently, the electrical conductivities improved by about 100 % leading to superior power factors (PF = 230 µW/mK² for CaMnO3). Another approach to reduce the production costs is to lower the sintering temperature by adding sinter additives. The addition of 4 wt% CuO to CaMnO3 lowers the sinter temperature from 1250 °C to 1050 °C. The achieved power factor PF = 264 µW/mK is more than two times higher as reported in literature for the same dopant. T2 - Virtual Conference on Thermoelectrics (VCT) CY - Online meeting DA - 21.07.2020 KW - Thermoelectrics KW - Reaction sintering KW - Sintering additives KW - Calcium manganate KW - Calcium cobaltite PY - 2020 AN - OPUS4-51070 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Sophie T1 - Improved thermoelectric properties of CaMnO3 and Ca3Co4O9 by increasing the driving force for sintering N2 - Thermoelectric materials can convert waste heat directly into electrical power by utilizing the Seebeck effect. Calcium cobaltite (Ca3Co4O9, p-type) and calcium manganate (CaMnO3, n-type) are two of the most promising oxide thermoelectric materials. The performance of these materials is evaluated by the power factor PF = S²∙σ and the figure of merit ZT = (PF ∙ T) / κ, demanding high Seebeck coefficient S, high electrical conductivity σ and low thermal conductivity κ. The latter two are increasing with increasing relative sinter density. According to theory, the relative density of ceramics can be improved by increasing the driving force for sintering. This study investigates different approaches to increase the driving force for sintering of Ca3Co4O9 and CaMnO3 to improve densities and thermoelectric properties. The following approaches were applied: minimizing the energy input during powder synthesis by calcination, fine milling of the powder, using reaction-sintering without a powder synthesis step, and adding a transient liquid phase by sinter additives. All different approaches led to an increased densification and thus higher electrical conductivity and higher PF. Thermal conductivity increased as well but not to the same extent. E.g. reaction-sintering increased the densification of Ca3Co4O9 (p-type) and CaMnO3 (n-type). Consequently, the electrical conductivities improved by about 100 % for both oxides leading to superior power factors (PF = 230 µW/mK² for CaMnO3). Although the thermal conductivity increased as well by 8 %, the figures of merit (ZT) were significantly higher compared to conventionally sintered bars. The addition of 4 wt% CuO as a sinter additive to CaMnO3 lowers the sinter temperature from above 1250 °C to below 1100 °C and increases the relative density. Due to the increased density, both electrical conductivity and PF increased by more than 200 % even though the sintering temperature was 150 K lower. T2 - Electroceramics XVII CY - Online meeting DA - 24.08.2020 KW - Thermoelectrics KW - Reaction sintering KW - Sintering additives PY - 2020 AN - OPUS4-51163 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Risse, S. A1 - Juhl, A. A1 - Mascotto, S. A1 - Arlt, T. A1 - Markötter, Henning A1 - Hilger, A. A1 - Manke, I. A1 - Fröba, M. T1 - Detailed and Direct Observation of Sulfur Crystal Evolution During Operando Analysis of a Li-S Cell with Synchrotron Imaging N2 - Herein, we present a detailed investigation of the electrochemically triggered formation and dissolution processes of α- and β-sulfur crystals on a monolithic carbon cathode using operando high-resolution synchrotron radiography (438 nm/pixel). The combination of visual monitoring with the electrical current response during cyclic voltammetry provides valuable insights into the sulfur formation and dissolution mechanism. Our observations show that the crystal growth process is mainly dictated by a rapid equilibrium between long-chain polysulfides on one side and solid sulfur/short-chain polysulfides on the other side, which is consistent with previous studies in this field. The high temporal and spatial resolution of synchrotron imaging enables the observation of different regimes during the sulfur formation and dissolution process. The appearance of short-chain polysulfides after the first anodic CV peak initiates a rapid dissolution process of α-sulfur crystals on the cathode. The increase in the long-chain lithium polysulfide concentration at the cathode surface during charge results in an increased crystal growth rate, which in turn produces imperfections in α- and β-sulfur crystals. There are strong indications that these defects are fluid inclusions, which may trap dissolved polysulfides and therefore reduce the electrochemical cell capacity. KW - LiS battery KW - Radiography KW - Synchrotron Imaging PY - 2020 DO - https://doi.org/10.1021/acs.jpclett.0c01284 VL - 11 IS - 14 SP - 5674 EP - 5679 AN - OPUS4-51100 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ziesche, R. F. A1 - Robinson, J. B. A1 - Markötter, Henning A1 - Bradbury, R. A1 - Tengattini, A. A1 - Lenoir, N. A1 - Helfen, L. A1 - Kockelmann, W. A1 - Kardjilov, N. A1 - Manke, I. A1 - Brett, D. J. L. A1 - Shearing, P. R. T1 - Editors’ Choice—4D Neutron and X-ray Tomography Studies of High Energy Density Primary Batteries: Part II. Multi-Modal Microscopy of LiSOCl2 Cells N2 - The ability to track electrode degradation, both spatially and temporally, is fundamental to understand performance loss during operation of lithium batteries. X-ray computed tomography can be used to follow structural and morphological changes in electrodes; however, the direct detection of electrochemical processes related to metallic lithium is difficult due to the low sensitivity to the element. In this work, 4-dimensional neutron computed tomography, which shows high contrast for lithium, is used to directly quantify the lithium diffusion process in spirally wound Li/SOCl2 primary cells. The neutron dataset enables the quantification of the lithium transport from the anode and the accumulation inside the SOCl2 cathode to be locally resolved. Complementarity between the collected neutron and X-ray computed tomographies is shown and by applying both methods in concert we have observed lithium diffusion blocking by the LiCl protection layer and identified all cell components which are difficult to distinguish using one of the methods alone. KW - Lithium-ion battery KW - Room-temperature KW - Thermal runaway KW - Gas evolution KW - Cells PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520890 DO - https://doi.org/10.1149/1945-7111/abbfd9 VL - 167 SP - 140509 PB - IOP Science AN - OPUS4-52089 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bresch, Sophie A1 - Mieller, Björn A1 - Schönauer-Kamin, D. A1 - Moos, R. A1 - Reimann, T. A1 - Giovannelli, F. A1 - Rabe, Torsten T1 - Influence of pressure and dwell time on pressure‐assisted sintering of calcium cobaltite N2 - Calcium cobaltite Ca3Co4O9, abbreviated Co349, is a promising thermoelectric material for high‐temperature applications in air. Its anisotropic properties can be assigned to polycrystalline parts by texturing. Tape casting and pressure‐assisted sintering (PAS) are a possible future way for a cost‐effective mass‐production of thermoelectric generators. This study examines the influence of pressure and dwell time during PAS at 900°C of tape‐cast Co349 on texture and thermoelectric properties. Tape casting aligns lentoid Co349. PAS results in a textured Co349 microstructure with the thermoelectrically favorable ab‐direction perpendicular to the pressing direction. By pressure variation during sintering, the microstructure of Co349 can be tailored either toward a maximum figure of merit as required for energy harvesting or toward a maximum power factor as required for energy harvesting. Moderate pressure of 2.5 MPa results in 25% porosity and a textured microstructure with a figure of merit of 0.13 at 700°C, two times higher than the dry‐pressed, pressureless‐sintered reference. A pressure of 7.5 MPa leads to 94% density and a high power factor of 326 µW/mK2 at 800°C, which is 11 times higher than the dry‐pressed reference (30 MPa) from the same powder. KW - Hot pressing KW - Texture KW - Thermoelectric properties PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515973 DO - https://doi.org/https://doi.org/10.1111/jace.17541 SN - 0002-7820 VL - 104 IS - 2 SP - 917 EP - 927 PB - Wiley Periodicals LLC AN - OPUS4-51597 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias T1 - Overview of metal seal tests performed at BAM and implications for extended interim storage N2 - The investigation of the long-term performance of sealing systems employed in containers for radioactive waste and spent nuclear fuel is one research focus area for division 3.4 “Safety of Storage Containers” at the Bundesanstalt für Materialforschung und -prüfung. The behaviour of metallic seals, which are employed in interim storage casks for used fuel and high active waste, over time is of high importance for ensuring safe enclosure. Therefore, investigations on these systems were started at BAM to get a general understanding of the relevant processes. Our investigations comprise investigations on different parameters which influence the seal performance and the main part is focussed on the time and temperature dependent behaviour. In this contribution an overview of the performed tests and their respective results will be given. A focus will lie on a comparison between seals with large torus diameter in comparison to small diameters. Our aim is to understand the long-term behaviour of the sealing systems for evaluation of their performance during possible extended interim storage and subsequent transportation. T2 - 4th Workshop on Safety of Extended Dry Storage of Spent Nuclear Fuel CY - Online meeting DA - 03.06.2020 KW - Seal performance KW - Metal seal KW - Leakage rate PY - 2020 AN - OPUS4-50843 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zaghdoudi, Maha T1 - Numerical modelling of compression stress relaxation and compression set of elastomer O-rings during aging N2 - Elastomer seals are used in many industrial applications due to their excellent mechanical properties at a wide range of temperatures. Their high versatility and recovery potential under several load conditions make them well suitable for the application in containers designed for transport, storage and/or disposal of radioactive materials. In containers for low and intermediate level radioactive waste, elastomer seals are used as barrier seals, and as auxiliary seals in storage and transportation casks (dual purpose casks) for heat generating radioactive waste, such as spent fuel and high-level waste. While a seal exchange at defined intervals is typical in many conventional applications, it is impossible or at least hard to perform when principles of minimization of radiation exposure have to be considered and prohibit an unnecessary cask handling. An extensive knowledge of the change of the elastomer’s properties during aging and the availability of reliable end-of-lifetime criteria to guarantee the permanent safe enclosure of the radioactive material is mandatory. As BAM is involved in most of the national cask licensing procedures and in the evaluation of cask-related long-term safety issues, great efforts have been already made and are still planned to scientifically support this task. Compression stress relaxation and compression set were identified as key indicators of elastomer long-term performance and quantitatively investigated in comprehensive test programs. Among other representative types of elastomers, specimens made from ethylene propylene diene rubber (EPDM) were tested before, during and after aging to capture the most important of their complex mechanical properties. In the presented study, exemplary results were used to simulate the compression stress relaxation and the compression set of elastomer O-rings during aging. Regarding the influence of temperature, the time temperature superposition principle is applied in the relaxation analysis of elastomer O-rings. The proposed model is implemented in the commercial finite element software ABAQUS/Standard® [1] with a sequential temperature displacement coupling. Numerical results match the experimental compression stress relaxation measurements well. The prediction of compression set values after long-term aging shows a relatively good agreement with the experimental results. Nevertheless, all input parameters derived from the specimen tests, additional assumptions concerning boundary conditions and modeling strategy are discussed with regard to the identified slight discrepancies. The possibility to extend the finite element model to represent the O-ring seal’s ability to recover after a (fast) partial release is taken into account T2 - ASME 2020 Pressure Vessels & Piping Conference (PVP2020) CY - Online meeting DA - 03.08.2020 KW - Stress relaxation KW - Ageing KW - Compression Set KW - O-ring KW - Sequential analysis KW - Simulation PY - 2020 AN - OPUS4-52135 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias T1 - Elastomer seals - overview and development N2 - The talk summarizes the current and future investigations of elastomer seal materials in division 3.4. T2 - IRSN-BAM Symposium Safety of Transport and Storage Packages CY - Online meeting DA - 19.11.2020 KW - Seal KW - Degradation KW - Ageing PY - 2020 AN - OPUS4-51751 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias T1 - Low temperature properties of rubber seals N2 - Understanding the failure mechanisms that lead to leakage of rubber seals at low temperatures is important. Rubber properties are highly temperature dependent. Changes in behaviour at low temperatures can result from the rubber-glass transition and for some rubbers by partial crystallisation. Experimental results on the low temperature behaviour of different rubber seals were discussed to help understand seal failure processes. T2 - Rubber in Engineering Group (RIEG) webinar an Elastomers at Low Temperatures CY - Online meeting DA - 11.09.2020 KW - Low temperature KW - Rubber seal KW - Compression set KW - Glass transition PY - 2020 UR - https://www.iom3.org/rubber-engineering-group/event/elastomers-low-temperatures AN - OPUS4-51306 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Jürgens, Maria T1 - Verhalten des hochwarmfesten Stahles P92 unter zyklischen thermo-mechanischen Bedingungen in lastflexiblen Dampfkraftwerken N2 - Die Erzeugung von Erneuerbaren Energien unterliegt starken Schwankungen, die von konventionellen Kraftwerken ausgeglichen werden müssen, um das Stromnetz stabil zu halten. Für die konventionellen Kraftwerke bedeutet dies eine zunehmend zyklische Fahrweise, die zu häufigeren Last- und Temperaturwechseln führt. Von den eingesetzten Werkstoffen fehlen Daten zum Verhalten unter zyklischer Fahrweise. Ziel dieser Arbeit ist es daher, für P92, einen als Rohrleitungswerkstoff eingesetzten hochwarmfesten Stahl, zu untersuchen, welche Auswirkungen zyklische Fahrweisen auf die Schädigungsprozesse und Lebensdauern haben. Da durch den zyklischen Betrieb eine verstärkte Schädigung durch Ermüdungsprozesse zu erwarten ist, wurden dehnungskontrollierte isotherme (LCF) und nicht-isotherme (TMF) Ermüdungsversuche mit und ohne Haltezeit bei verschiedenen Temperaturen bzw. Temperaturintervallen durchgeführt. Mit den Haltezeitversuchen soll dabei das Kriech-Ermüdungs-Verhalten untersucht werden. Bei den TMF-Versuchen wurde zusätzlich die Temperaturrate variiert, um näher an den realen Lastwechselgeschwindigkeiten zu prüfen. Schließlich wurden auf Basis der durchgeführten LCF- und TMF-Versuche betriebsnahe Versuchsprozeduren entwickelt, um unterschiedliche Betriebsmodi in einem Versuch abzubilden. Die durchgeführten mechanischen Versuche stellen eine umfangreiche Basis zu Ermüdungsdaten an P92 dar. Neben der Abhängigkeit der Lebensdauer von Temperatur, Temperaturintervall und –rate, sowie Dehnung und Haltezeit, konnte auch das Entfestigungsverhalten genauer charakterisiert werden. Sowohl Haltezeiten als auch das Reduzieren der Temperaturrate können die Lebensdauer erheblich verringern. Dabei kommt es gerade bei vermeintlich kleinen Dehnungen, bei denen die Streckgrenze nur leicht überschritten wird, zu einer Lebensdauerreduzierung. Haltezeiten verstärken zudem die zyklische Entfestigung. Die fraktographische Analyse der Proben hat ergeben, dass es keinen direkten Zusammenhang zwischen der Entfestigung und der Bildung von Nebenrissen gibt. Stattdessen zeigen EBSD- und TEM-Untersuchungen, dass es zur Bildung einer Subkornstruktur kommt und die Entfestigung auf dem Verschwinden von Kleinwinkelkorngrenzen beruht. Während bei den LCF-Proben eine reine Ermüdungsschädigung vorliegt, konnte bei einigen TMF-Proben eine kriechdominierende Schädigung nachgewiesen werden. Die betriebsnahen Zyklen zeigen, dass sich mit den durchgeführten Versuchen das reale Betriebsverhalten gut abschätzen lässt. Da es jedoch auch Parameterkombinationen gibt, bei denen keine Änderung des Entfestigungs- und Lebensdauerverhaltens auftritt, sollte genau bekannt sein, welche Belastungen in einem Bauteil auftreten. KW - P92 KW - LCF KW - TMF KW - Energiewende KW - Kriechermüdung KW - Energy transition KW - Creep-fatigue PY - 2020 DO - https://doi.org/10.14279/depositonce-10538 SP - 1 EP - 144 CY - Berlin AN - OPUS4-51571 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lutz, C. A1 - Hampel, S. A1 - Ke, X. A1 - Beuermann, S. A1 - Turek, T. A1 - Kunz, U. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Fittschen, U. T1 - Evidence for redox reactions during vanadium crossover inside the nanoscopic water-body of Nafion 117 using X-ray absorption near edge structure spectroscopy N2 - A major source of capacity fade of the common vanadium redox flow battery (VRFB) is the vanadium ion transport through the separator. However, different transport models disagree significantly in the diffusion coefficient for the different V species and the influence of different transport mechanisms. The underlying hypothesis of this work is that reactions inside the membrane are partly responsible for these discrepancies. Accordingly, it was investigated if redox reactions inside the nanoscopic water body of Nafion 117 can occur. X-ray absorption near edge structure spectroscopy (XANES) was used to distinguish between the different V species inside hydrated Nafion 117 and novel PVDF-based membranes. It was validated that the speciation of vanadium can be performed using the pre-edge peak energy and intensity. The experiments were performed as follows: strips of the membrane were exposed from one site to a V3+ solution (green) and from the other site to a VO2+ solution (yellow). The ions could diffuse into the membrane from both sides. A change of color of the membrane strip was observed. The blue color in the middle of the strip indicated that VO2+ was formed where V3+ and VO2+ got in contact. Using XANES this reaction inside Nafion was proven. KW - PVDF-Based membrane KW - VRFB KW - Vanadium speciation KW - XANES KW - Nafion 117 PY - 2020 DO - https://doi.org/10.1016/j.jpowsour.2020.229176 VL - 483 SP - 229176 PB - Elsevier B.V. AN - OPUS4-51719 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Long, Lijia A1 - Anh Mai, Q. A1 - Morato, P. G. A1 - Dalsgaard Sorensen, J. A1 - Thöns, Sebastian T1 - Information value-based optimization of structural and environmental monitoring for offshore wind turbines support structures N2 - The use of load and structural performance measurement information is vital for efficient structural integrity management and for the cost of energy production with Offshore Wind Turbines (OWTs). OWTs are dynamically sensitive structures subject to an interaction with a control unit exposed to repeated cyclic wind and wave loads causing deterioration and fatigue. This study focuses on the quantification of the value of structural and environmental information on the integrity management of OWT structures, with the focus on fatigue of welded joints. By utilizing decision analysis, structural reliability methods, measurement data, as well as the cost-benefit models, a Value of Information (VoI) analysis can be performed to quantify the most beneficial measurement strategy. The VoI assessment is demonstrated for the integrity management of a butt welded joint of a monopile support structure for a 3 MW OWT with a hub height of approximately 71m. The conditional value of three-year measured oceanographic information and one-year strain monitoring information is quantified posteriori in conjunction with an inspection and repair planning. This paper provides insights on how much benefits can be achieved through structural and environmental information, with practical relevance on reliability-based maintenance of OWT structures. KW - Structural health monitoring KW - Offshore wind turbine KW - Monopile support structure KW - Value of information KW - Weld fatigue KW - Decision tree KW - Dynamic Bayesian Network PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-514098 DO - https://doi.org/10.1016/j.renene.2020.06.038 VL - 10 IS - 159 SP - 1036 EP - 1046 PB - Elsevier Ltd. AN - OPUS4-51409 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Röhsler, Andreas A1 - Sobol, Oded A1 - Hänninen, H. A1 - Böllinghaus, Thomas T1 - In-situ ToF-SIMS analyses of deuterium re-distribution in austenitic steel AISI 304L under mechanical load N2 - Hydrocarbons fuel our economy. Furthermore, intermediate goods and consumer products are often hydrocarbon-based. Beside all the progress they made possible, hydrogen-containing substances can have severe detrimental effects on materials exposed to them. Hydrogen-assisted failure of iron alloys has been recognised more than a century ago. The present study aims to providing further insight into the degradation of the austenitic stainless steel AISI 304L (EN 1.4307) exposed to hydrogen. To this end, samples were electrochemically charged with the hydrogen isotope deuterium (2H, D) and analysed by scanning electron microscopy (SEM), electron back-scatter diffraction (EBSD) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). It was found that deuterium caused a phase transformation from the original γ austenite into ε- and α’-martensite. Despite their low solubility for hydrogen, viz. deuterium, the newly formed phases showed high deuterium concentration which was attributed to the increased density of traps. Information about the behaviour of deuterium in the material subjected to external mechanical load was gathered. A four-point-bending device was developed for this purpose. This allowed to analyse in-situ pre-charged samples in the ToF-SIMS during the application of external mechanical load. The results indicate a movement of deuterium towards the regions of highest stress. KW - ToF-SIMS KW - Hydrogen KW - Deuterium KW - AISI 304L KW - EBSD PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505142 DO - https://doi.org/10.1038/s41598-020-60370-2 VL - 10 IS - 1 SP - 3611 PB - Nature AN - OPUS4-50514 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Schneider, Ronald T1 - Time-variant reliability of deteriorating structural systems conditional on inspection and monitoring data N2 - The current practice of operating and maintaining deteriorating structural systems ensures acceptable levels of structural reliability, but it is not clear how efficient it is. Changing the current prescriptive approach to a risk-based approach has great potential to enable a more efficient management of such systems. Risk-based optimization of operation and maintenance strategies identifies the strategy that optimally balances the cost for controlling deterioration in a structural system with the achieved risk reduction. Inspections and monitoring are essential parts of operation and maintenance strategies. They are typically performed to reduce the uncertainty in the structural condition and inform decisions on future operation and maintenance actions. In risk-based optimization of operation and maintenance strategies, Bayesian updating is used to include information contained in inspection and monitoring data in the prediction of the structural reliability. All computations need to be repeated many times for different potential inspection and monitoring outcomes. This motivates the development of robust and efficient approaches to this computationally challenging task. The reliability of deteriorating structural systems is time-variant because the loads on them and their capacities change with time. In most practical applications, the reliability analysis of deteriorating structural systems can be approached by dividing their lifetime into discrete time intervals. The time-variant reliability problem can then be represented by a series of time-invariant reliability problems. Using this methodology as a starting point, this thesis proposes a novel approach to compute the time-variant reliability of deteriorating structural systems for which inspection and monitoring data are available. The problem is formulated in a nested way in which the prediction of the structural condition is separated from the computation of the structural reliability conditional on the structural condition. Information on the structural condition provided by inspections and monitoring is included in the reliability assessment through Bayesian updating of the system deterioration model employed to predict the structural condition. The updated system reliability is obtained by coupling the updated deterioration model with a probabilistic structural model utilized to calculate the failure probability conditional on the structural condition. This approach is the first main outcome of this thesis and termed nested reliability analysis (NRA) approach. It is demonstrated in two numerical examples considering inspected and monitored steel structures subject to high-cycle fatigue. An alternative – recently developed – approach, which also follows the strategy of discretizing time, describes deteriorating structural systems with hierarchical dynamic Bayesian networks (DBN). DBN combined with approximate or exact inference algorithms also enable the computation of the time-variant reliability of deteriorating structural systems conditional on information provided by inspection and monitoring data. In this thesis – as a proof of concept – a software prototype is developed based on the DBN approach, which can be used to assess the reliability of a corroding concrete box girder for which half-cell potential measurements are available. This is the second main outcome of this thesis. Both approaches presented in this thesis enable an integral reliability analysis of inspected and monitored structures that accounts for system effects arising from (a) the correlation among deterioration states of different structural elements, (b) the interaction between element deterioration and system failure, and (c) the indirect information gained on the condition of all unobserved structural elements from inspecting or monitoring the condition of some structural elements. Thus, both approaches enable a systemwide risk-based optimization of operation and maintenance strategies for deteriorating structural systems. The NRA approach can be implemented relatively easily with subset simulation, which is a sequential Monte Carlo method suitable for estimating rare event probabilities. Subset simulation is robust and considerably more efficient than crude Monte Carlo simulation. It is, however, still sampling-based and its efficiency is thus a function of the number of inspection and monitoring outcomes, as well as the value of the simulated event probabilities. The current implementation of the NRA approach performs separate subset simulation runs to estimate the reliability at different points in time. The efficiency of the NRA approach with subset simulation can be significantly improved by exploiting the fact that failure events in different years are nested. The lifetime reliability of deteriorating structural systems can thus be computed in reverse chronological order in a single subset simulation run. The implementation of the DBN approach is much more demanding than the implementation of the NRA approach but it has two main advantages. Firstly, the graphical format of the DBN facilitates the presentation of the model and the underlying assumptions to stakeholders who are not experts in reliability analysis. Secondly, it can be combined with exact inference algorithms. In this case, its efficiency neither depends on the number of inspection and monitoring outcomes, nor on the value of the event probabilities to be calculated. However, in contrast to the NRA approach with subset simulation, the DBN approach with exact inference imposes restrictions on the number of random variables and the dependence structure that can be implemented in the model. T3 - BAM Dissertationsreihe - 168 KW - Reliability KW - Structural systems KW - Deterioration KW - Bayesian analysis KW - Inspection KW - Monitoring KW - Zuverlässigkeit KW - Tragstrukturen KW - Schädigungsprozesse KW - Bayes'sche Analyse KW - Inspektion KW - Monitoring PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512977 SN - 1613-4249 VL - 168 SP - 1 EP - 188 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-51297 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Opitz, P. A1 - Besch, L. A1 - Panthöfer, M. A1 - Kabelitz, Anke A1 - Unger, R. A1 - Emmerling, Franziska A1 - Mondeshki, M. A1 - Tremel, W. T1 - Insights into the In Vitro Formation of Apatite from Mg‐Stabilized Amorphous Calcium Carbonate N2 - A protein‐free formation of bone‐like apatite from amorphous precursors through ball‐milling is reported. Mg2+ ions are crucial to achieve full amorphization of CaCO3. Mg2+ incorporation generates defects which strongly retard a recrystallization of ball‐milled Mg‐doped amorphous calcium carbonate (BM‐aMCC), which promotes the growth of osteoblastic and endothelial cells in simulated body fluid and has no effect on endothelial cell gene expression. Ex situ snapshots of the processes revealed the reaction mechanisms. For low Mg contents (<30%) a two phase system consisting of Mg‐doped amorphous calcium carbonate (ACC) and calcite “impurities” was formed. For high (>40%) Mg2+ contents, BM‐aMCC follows a different crystallization path via magnesian calcite and monohydrocalcite to aragonite. While pure ACC crystallizes rapidly to calcite in aqueous media, Mg‐doped ACC forms in the presence of phosphate ions bone‐like hydroxycarbonate apatite (dahllite), a carbonate apatite with carbonate substitution in both type A (OH−) and type B (PO43−) sites, which grows on calcite “impurities” via heterogeneous nucleation. This process produces an endotoxin‐free material and makes BM‐aMCC an excellent “ion storage buffer” that promotes cell growth by stimulating cell viability and metabolism with promising applications in the treatment of bone defects and bone degenerative diseases. KW - Total Scattering KW - XRD KW - Mechanochemistry PY - 2020 DO - https://doi.org/10.1002/adfm.202007830 VL - 31 IS - 3 SP - 7830 PB - Wiley VHC-Verlag AN - OPUS4-51761 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -