TY - CONF A1 - John, Sebastian A1 - Widjaja, Martinu A1 - Mair, Georg T1 - Modalanalyse als Werkzeug zur Lebensdauerabschätzung bei Composite-Druckbehältern N2 - Hochbeanspruchte Bauteile wie Druckbehälter bergen im Falle eines Versagens ein erhebliches Gefährdungspotential für Mensch und Umgebung. Trotz der Auslegung mit hohen Sicherheitsfaktoren kommt es durch die hauptsächlich bei mobilen Anwendungen eingesetzten Leichtbauwerkstoffe und Materialkombinationen zu komplexen Degradations- und Schädigungsvorgängen, welche unter ungünstigen Umständen zu einem frühzeitigen Versagen führen können. Die hier vorgestellten Untersuchungen beziehen sich auf Typ IV-Gasspeicher, die als Wasserstofftanks in KFZ zur Anwendung kommen. Durch den Einsatz eines Messverfahrens auf Basis einer experimentellen Modalanalyse (EMA) sollen Schädigungs- und Degradationsgrad künftig zerstörungsfrei erfasst und auch einsatzbegleitend überwacht werden können. T2 - DAGA 2021 - 47. Jahrestagung für Akustik CY - Wien, Österreich DA - 15.08.2021 KW - Impact KW - Modalanalyse KW - Druckbehälter PY - 2021 VL - 47 SP - 1202 EP - 1205 AN - OPUS4-53626 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Widjaja, Martinus Putra A1 - Moosavi, Robabeh A1 - John, Sebastian A1 - Schumacher, David A1 - Grunwald, Marcel A1 - Auster, Jürgen A1 - Szczepaniak, Marius A1 - Mair, Georg A1 - Waske, Anja T1 - Impact damage evaluation of hydrogen composite pressure vessels by analysing computed tomography images N2 - The objective of this work is to find a method that describes the degree of damage from an impact experiment. This experiment was performed on Composite Pressure Vessels (CPV) in order to find the correlation of impact damage to the residual burst pressure. Computed Tomography (CT) approach was used to capture the before and after impact condition of the CPVs. The Wasserstein function was used to calculate how much the after impact image has differed from the original one. In the end, a good correlation was obtained to the residual burst pressure. T2 - HyFiSyn Conference CY - Online meeting DA - 15.09.2021 KW - Hydrogen KW - Composite pressure vessel KW - Carbon fibre KW - Burst test KW - Image analysis KW - Computed tomography (CT) PY - 2021 SP - 31 EP - 32 AN - OPUS4-53494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wang, Bin A1 - Mair, Georg A1 - Islam, F. T1 - Evaluation methods for estimation of Weibull parameters used in Monte Carlo simulations for safety analysis of pressure vessels N2 - The test data for static burst strength and load cycle fatigue strength of pressure vessels can often be well described by Gaussian normal or Weibull distribution functions. There are various approaches which can be used to determine the parameters of the Weibull distribution function; however, the performance of these methods is uncertain. In this study, six methods are evaluated by using the criterion of OSL (observed significance level) from Anderson-Darling (AD) goodness of Fit (GoF), These are: a) the norm-log based method, b) least squares regression, c) weighted least squares regression, d) a linear approach based on good linear unbiased estimators, e) maximum likelihood estimation and f) method of moments estimation. In addition, various approaches of ranking function are considered. The results show that there are no outperforming methods which can be identified clearly, primarily due to the limitation of the small sample size of the test data used for Weibull analysis. This randomness resulting from the sampling is further investigated by using Monte Carlo simulations, concluding that the sample size of the experimental data is more crucial than the exact method used to derive Weibull parameters. Finally, a recommendation is made to consider the uncertainties of the limitations due to the small size for pressure vessel testing and also for general material testing. KW - Safety assessment KW - Weibull distribution parameters KW - Randomness KW - Sample size KW - Monte Carlo simulation PY - 2021 U6 - https://doi.org/10.1515/mt-2020-0058 VL - 63 IS - 4 SP - 279 EP - 385 PB - De Gruyter AN - OPUS4-53105 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mair, Georg T1 - Salvage pressure receptacles - Technical background N2 - The presentation reflects the questions that have been raised by member states and NGOs. As background information details on the question how to choose a suitable salvage pressure receptacle (SPR) are provided. This leads to the need for deleting the volume limitation for SPRs and to the discussions in 2014 and 2016 on this issue. As an adequate substitution for deleting the volume limit for SPRs it is proposed to limit the pressure receptacles to be stored in by a maximum pressure-volume-value of 1.5 Mio bar-litres. After some explanations to standardisation projects currently also tackling this pV-limit, some risk-based safety criteria for a limitation are mentioned with the focus of the consequence level and the general avoidance of catastrophic worst case scenarios. T2 - 57th session of TDG Sub-Committee CY - Online meeting DA - 30.11.2020 KW - Salvage pressure receptacle KW - Consequence KW - Catastrophe KW - Compressed gas PY - 2020 AN - OPUS4-53161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mair, Georg 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 A1 - Bock, Robert T1 - Burst strength and its scatter as key points of safety N2 - Based on the preliminary presentations in this task force it is repeated how a basic population scatters and its degradation influences properties statistically. There is a remainder on the issue of accepting borderline populations due to the minimum burst ratio requirement. Then it is explained in detail how the analysis of minimum requirements by a Monte-Carlo-simulation works. The result with respect to the further reduced minimum burst ratio of 2.0 is summarised and means a two-step approach of two scatter levels requiring two different minimum burst ratios. The methods for evaluating batch tests are analysed. A proposal for integration a statistical analysis is described in detail. Finally, the positive effect of proof testing is shown and its dependence from the real ageing is shown. This ends in the recommendation to have a stronger and quantitative look on real ageing and to follow the 2 proposed sets of criteria for a safe usage of hydrogen storage systems. T2 - 10th IWG on rev GTR 13 CY - Online meeting DA - 28.06.2021 KW - Basic population KW - Minimum burst ratio KW - Monte-Carlo-simulation KW - Borderline population KW - Batch test KW - Proof test KW - Ageing PY - 2021 UR - https://wiki.unece.org/download/attachments/128419731/GTR13-10-08%20BAM%20GTR%2013-2%20scatter%20criteria%20for%20min%20burst%202021-06-25.pdf?api=v2 AN - OPUS4-53149 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Solberg, S. A1 - Zimmermann, P. A1 - Wilhelmsen, Ø. A1 - Lamb, J. A1 - Bock, Robert A1 - Burheim, O. T1 - Heat to Hydrogen by Reverse Electrodialysis—Using a Non-Equilibrium Thermodynamics Model to Evaluate Hydrogen Production Concepts Utilising Waste Heat N2 - The reverse electrodialysis heat engine (REDHE) is a promising salinity gradient energy technology, capable of producing hydrogen with an input of waste heat at temperatures below 100 °C. A salinity gradient drives water electrolysis in the reverse electrodialysis (RED) cell, and spent solutions are regenerated using waste heat in a precipitation or evaporation unit. This work presents a non-equilibrium thermodynamics model for the RED cell, and the hydrogen production is investigated for KCl/water solutions. The results show that the evaporation concept requires 40 times less waste heat and produces three times more hydrogen than the precipitation concept. With commercial evaporation technology, a system efficiency of 2% is obtained, with a hydrogen production rate of 0.38 gH2 m−2h−1 and a waste heat requirement of 1.7 kWh g−1H2. The water transference coefficient and the salt diffusion coefficient are identified as membrane properties with a large negative impact on hydrogen production and system efficiency. Each unit of the water transference coefficient in the range tw=[0–10] causes a −7 mV decrease in unit cell electric potential, and a −0.3% decrease in system efficiency. Increasing the membrane salt diffusion coefficient from 10−12 to 10−11 leads to the system efficiency decreasing from 2% to 0.6% KW - Non-equilibrium thermodynamics KW - Hydrogen KW - Waste heat KW - RED PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-556677 VL - 15 IS - 16 SP - 6011 PB - MDPI AN - OPUS4-55667 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 - 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 - Mair, Georg T1 - Sicherheitsforschung im Bereich Wasserstoff – Transport von CGH2 N2 - Ein Aspekt des Gefahrguttransportes, der an Bedeutung in den letzten Jahren zugenommen hat, ist die Versorgung von Wasserstofftankstellen und anderen H2-Großverbrauchern über die Schiene aber insbesondere über die Straße. Mit Blick auf die primäre Form der Speicherung wird der Begriff der Sicherheit über den Aspekt der Häufigkeit eines definierten Ereignisses erläutert und auf die Besonderheiten der Druckgefäße aus Verbundwerkstoffen hingewiesen, wie auch den regulatorischen Hintergrund der Lebensdauerüberprüfung nach 15 Jahren nach den Vorgaben der zuständigen Behörde. In Deutschland sind diese Vorgaben in der BAM-Gefahrgutregel 021 geregelt, die in der GGR 022 durch eine Regelung zur Wiederkehrenden Prüfung dieser Umschließungen ergänzt wird. Beide BAM-Gefahrgutregeln basieren auf einem probabilistischen Ansatz und einer Konsequenzabschätzung über das Druck-Volumen-Produkt der Druckgefäße. Die neu im Recht verankerte EN 17339 ist die erste Norm, die speziell fest montierte Compositespeicher für den Wasserstofftransport regelt. Sie ermöglicht eine erhebliche Gewichtreduktion und führt eine Obergrenze für das Druckvolumen ein. Es wird kurz erläutert, dass gerade mit Blick auf Wasserstofftransporte über eine Arbeitsgruppe der Vereinten Nationen eine Begrenzung des Konsequenzpotentials in das internationale Recht eingeführt werden soll und welche Kriterien bei der systematischen Ermittlung des akzeptierten Wertes von 1.5 Mio bar Liter Einfluss haben. Mit Blick auf die Energiewende sieht es die BAM als besonders wichtig an, die Transportkosten zu senken, indem der Prüfaufwand reduziert und gleichzeitig die Erkenntnistiefe aus der betrieblichen Überwachung verbessert wird. Hierzu muss die Datenbasis für die probabilistische Bewertung der Lebensdauer von zerstörenden Prüfungen auf zerstörungsfreie Prüfungen umgestellt werden und idealerweise die 100% Prüfung zumindest in der ersten Hälfte des sicheren Lebens auf Stichproben reduziert werden. Dies und andere Aufgaben, die wichtig für eine sichere und attraktive Wasserstoffwirtschaft sind werden von dem Kompetenzzentrum H2Safety@BAM bearbeitet, dass in seinen Grundzügen kurz vorgestellt wird. T2 - IAA Transportation 2022 CY - Hannover,Germany DA - 20.09.2022 KW - H2Safety@BAM KW - Markthochlauf KW - Lebensdauervorhersage KW - zerstörungsfreie Prüfung ZfP KW - Risikosteuerung PY - 2022 AN - OPUS4-56984 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -