TY - JOUR
A1 - Mair, Georg W.
A1 - Hoffmann, Martin
A1 - Scherer, Florian
A1 - Schoppa, André
A1 - Szczepaniak, Mariusz
T1 - Slow burst testing of samples as a method for quantification of composite cylinder degradation
N2 - The current practise to focus periodic retesting of composite cylinders primarily on the hydraulic pressure test has to be evaluated as critical. The test itself always causes a certain amount of micro damage to the cylinders but does not necessarily deliver sufficient and evaluable information. Thus BAM Federal Institute of Materials Research and Testing (Germany) moves the focal point to a new approach for validation of composite cylinders, based on destructive sample tests parallel to operation. Statistical assessment of results of these destructive tests is employed for the estimation of remaining safe service life, based on reliability demands. The estimated service life is also used for the determination of re-test periods of the examined population of composite cylinders.
An essential aspect of this approach is the validation of current residual strength and its prediction at any point of service life. In cases of gas cylinders with very high cycle strength, residual strength cannot be quantified statistically by means of hydraulic load cycles. As a replacement, creep tests or burst tests may be employed. BAM suggests the 'slow burst test SBT' as a combination of these two test procedures. This is a compromise between the practicability of the (conventional) burst test and the practical relevance of sustained loads during service, to be tested in creep rupture tests. In this paper, a variety of 99 burst results of a cylinder design type used for breathing apparatus (CFRP with PE-liner) is evaluated. The influence of test procedure parameters and nature and intensity of artificial ageing on the test sample strength are analysed statistically. This leads to an evaluation of different procedures of artificial ageing and the recommendation to substitute conventional burst tests by slow burst tests for the assessment of composite pressure receptacles.
KW - Slow burst test
KW - Sample testing
KW - Residual strength
KW - Scatter
KW - Mean value
KW - Degradation
KW - Pressure rate
PY - 2014
DO - https://doi.org/10.1016/j.ijhydene.2014.04.016
SN - 0360-3199
VL - 39
IS - 35
SP - 20522
EP - 20530
PB - Elsevier
CY - Oxford
AN - OPUS4-30732
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Mair, Georg W.
A1 - Hoffmann, Martin
A1 - Scherer, Florian
T1 - Type approval of composite gas cylinders - Probabilistic analysis of rc&s concerning minimum burst pressure
T2 - EHEC 2014 - European hydrogen energy conference
CY - Seville, Spain
DA - 2014-03-12
KW - Composite cylinders
KW - Cost optimisation
KW - Hydraulic cycle testing
KW - Residual strength
KW - Safety
KW - Scatter
KW - Slow burst
KW - Pressure rate
KW - Sustained load
PY - 2014
SP - HS2-6, 242-244
AN - OPUS4-30739
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mair, Georg W.
A1 - Scherer, Florian
A1 - Hoffmann, Martin
T1 - Type approval of composite gas cylinders - Probabilistic analysis of standards' requirements concerning minimum burst pressure
N2 - Gas cylinders made from composite materials receive growing popularity in applications where light weight is of advantage. At the same time manufacturers are interested in cutting cost and weight through material reduction for better acceptance of a product, e.g. H2-vehicles. This requires a better understanding of safety relevant properties.
The safety determination of current standards is mainly based on the minimum burst pressure of a few specimens. Various research projects were conducted aiming at reducing minimum burst pressure requirements without compromising safety. No satisfying results were found. While looking at reliability aspects it could be concluded, that the minimum burst pressure of unused specimens is not a satisfying criterion for safety during service life.
This paper introduces first ideas for a method to determine one aspect of reliability of composite gas cylinders, employing probabilistic analysis of burst pressures of a sample of specimens. This can create potential for saving material cost while granting a higher safety level than the current method. Additionally, degradation over service time can be assessed.
KW - Probabilistic approach
KW - Regulations
KW - Artificial aging
KW - Slow burst test
KW - Survival rate
KW - Degradation trace
KW - Isoasfalen
PY - 2015
DO - https://doi.org/10.1016/j.ijhydene.2015.01.161
SN - 0360-3199
VL - 40
IS - 15
SP - 5359
EP - 5366
PB - Elsevier Ltd.
CY - Oxford
AN - OPUS4-32697
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mair, Georg W.
A1 - Hoffmann, Martin
T1 - Assessment of the residual strength thresholds of composite pressure receptacles - Criteria for hydraulic load cycle testing
N2 - Die aktuelle Praxis, die wiederkehrende Prüfung von Druckgefäßen aus Verbundwerkstoffen primär auf die hydraulische Innendruckprüfung zu begründen, ist kritisch sowohl bzgl. der Mikro-Schädigung der Prüfmuster als auch bzgl. ihrer Aussagekraft zu bewerten. Deshalb kommt durch die Bundesanstalt für Materialforschung und -prüfung BAM bei der Zulassung von Prüffristen für Composite-Druckgefäße von mehr als 5 Jahren zur Absicherung ein neuer Validierungsansatz zur Anwendung. Er ermöglicht eine Zustandsbeschreibung der Gesamtheit eines Baumusters auf der Basis wiederholt betriebsbegleitend zerstörender Prüfungen. Mit Bezug auf diesen Ansatz wird erläutert, wie die statistische Auswertung von Stichproben und deren perspektivische Extrapolation zur Vorhersage des Endes der Lebensdauer bzw. zumindest des Zeitpunkts der nächsten wiederholten Prüfung erfolgen können. Ferner wird erläutert, wie Zuverlässigkeitsgrenzwerte von der Größe von Druckgefäßen abhängig gemacht werden können und welchen Einfluss der reale Gasdruck auf die Sicherheitsbewertung im Rahmen des Ansatzes der BAM hat. Es wird insbesondere in das zentrale Arbeitsdiagramm des vorgenannten Ansatzes, das für Sicherheitsbewertungen wesentlich ist, eingeführt und erläutert, wie dieses verwendet werden kann. Hierzu wird auch ausgeführt, wie die Füllzyklenzahl und die Lastwechselfestigkeit über die neu eingeführte Größe der spezifischen Füllempfindlichkeit zusammenhängen.
N2 - The current practice of periodic retesting of composite pressure receptacles primarily based on the hydraulic pressure test has to be evaluated as critical.
This is justified by micro damages caused to the specimen by the test
itself and by a lack of informative values. Thus, BAM Federal Institute of Materials Research and Testing uses a new validation approach in the case of retest periods of more than 5 years. It enables the description of the condition of a specific design type series based on destructive tests parallel to operation. With respect to this approach it is explained how the statistical evaluation of sample tests and their extrapolation to end of life or at least to the time of next retesting can be achieved. In addition, it is explained how the reliability limits may be linked to the size and pressure level of the respective composite pressure receptacle. The frame of this safety Approach includes the influence of the maximum working pressure on the safety assessment.
One topic of this approach is the introduction of the working diagram
essential for safety assessments that allows graphical evaluation of load cycle strength by mean value, scatter and survival rate of samples as well as instruction how to use it. For this, it is explained how the number of filling cycles and the reduction of the respective hydraulic residual cycle strength interacts with the newly introduced value of specific filling sensitivity.
KW - Composite cylinders
KW - Hydraulic cycle testing
KW - Residual strength
KW - Sample testing
KW - Probabilis-tic
PY - 2013
SN - 0025-5300
VL - 55
IS - 2
SP - 121
EP - 129
PB - Hanser
CY - München
AN - OPUS4-27645
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mair, Georg W.
A1 - Hoffmann, Martin
T1 - Regulations and research on RC&S for hydrogen storage relevant to transport and vehicle issues with special focus on composite containments
N2 - Developers interested in high pressure storage of hydrogen for mobile use increasingly rely on composite cylinders for onboard storage or transport of dangerous goods. Thus, composite materials and systems deserve special consideration. History gives interesting background information important to the understanding of the current situation as to regulations, codes and standards.
Based on this review, origins of different regulations for the storage of hydrogen as dangerous good and as propellant for vehicles will be examined. Both categories started out using steel and sometimes aluminium as cylinder material. With composite materials becoming more common, a new problem emerged: vital input for regulations on composite pressure systems was initially derived from decades of experience with steel cylinders. As a result, both regulatory fields suffer somewhat from this common basis. Only recent developments regarding requirements for composite cylinders have begun to go more and more separate ways. Thus these differences lead to some shortcomings in regulation with respect to composite storage systems.
In principle, in spite of separate development, these deficits are in both applications very much the same: there are uncertainties in the prediction of safe service life, in retesting procedures of composite cylinders and in their intervals. Hence, different aspects of uncertainties and relevant approaches to solutions will be explained.
KW - Regulations
KW - Hydrogen storage
KW - Composite cylinders
KW - Safety
KW - Slow burst test
KW - Cycle fatigue sensitivity
PY - 2014
DO - https://doi.org/10.1016/j.ijhydene.2013.08.141
SN - 0360-3199
VL - 39
IS - 11
SP - 6132
EP - 6145
PB - Elsevier
CY - Oxford
AN - OPUS4-29218
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Mair, Georg W.
A1 - Hoffmann, Martin
A1 - Schönfelder, Thorsten
ED - Carcassi, M.N.
T1 - The slow burst testing of composite cylinders - Part I: Slow burst testing of samples as a method for quantification of cylinder degradation
N2 - The current practise of focusing the periodic retesting of composite cylinders primarily on the hydraulic pressure test has to be evaluated as critical - with regard to the damage of the specimen as well as in Terms of their significance. This is justified by micro damages caused to the specimen by the test itself and by a lack of informative values. Thus BAM Federal Institute of Materials Research and Testing (Germany) uses a new approach of validation of composite for the determination of re-test periods. It enables the description of the state of a population of composite cylinders based on destructive tests parallel to operation.
An essential aspect of this approach is the prediction of residual safe service life. In cases where it cannot be estimated by means of hydraulic load cycle tests, as a replacement the creep or burst test remains. As a combination of these two test procedures BAM suggests the 'slow burst test SBT'. On this a variety of about 150 burst test results on three design types of cylinders with plastic liners are presented. For this purpose both, the parameters of the test protocol as well as the nature and intensity of the pre-damage artificially aged test samples are analysed statistically. This leads first to an evaluation of the different types of artificial ageing but also to the clear recommendation that conventional burst tests be substituted
totally if indented for assessment of composite pressure receptacles.
T2 - ICHS2013 - 5th International conference on hydrogen safety
CY - Brussels, Belgium
DA - 09.09.2013
KW - Residual strength
KW - CFRP
KW - Gas storage
KW - Reliability
KW - Sample testing
PY - 2013
SN - 978-2-9601366-0-9
SP - 1
EP - 12
AN - OPUS4-29260
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Chan, George C.-Y.
A1 - Hieftje, Gary M.
A1 - Omenetto, Nicoló
A1 - Axner, Ove
A1 - Bengtson, Arne
A1 - Bings, Nicolas H.
A1 - Blades, Michael W.
A1 - Bogaerts, Annemie
A1 - Bolshov, Mikhail A.
A1 - Broekaert, José A.C.
A1 - Chan, WingTat
A1 - Costa-Fernández, José M.
A1 - Crouch, Stanley R.
A1 - De Giacomo, Alessandro
A1 - D’Ulivo, Alessandro
A1 - Engelhard, Carsten
A1 - Falk, Heinz
A1 - Farnsworth, Paul B.
A1 - Florek, Stefan
A1 - Gamez, Gerardo
A1 - Gornushkin, Igor B.
A1 - Günther, Detlef
A1 - Hahn, David W.
A1 - Hang, Wei
A1 - Hoffmann, Volker
A1 - Jakubowski, Norbert
A1 - Karanassios, Vassili
A1 - Koppenaal, David W.
A1 - Kenneth Marcus, R.
A1 - Noll, Reinhard
A1 - Olesik, John W.
A1 - Palleschi, Vincenzo
A1 - Panne, Ulrich
A1 - Pisonero, Jorge
A1 - Ray, Steven J.
A1 - Resano, Martín
A1 - Russo, Richard E.
A1 - Scheeline, Alexander
A1 - Smith, Benjamin W.
A1 - Sturgeon, Ralph E.
A1 - Todolí, José-Luis
A1 - Tognoni, Elisabetta
A1 - Vanhaecke, Frank
A1 - Webb, Michael R.
A1 - Winefordner, James D.
A1 - Yang, Lu
A1 - Yu, Jin
A1 - Zhang, Zhanxia
T1 - Landmark Publications in Analytical Atomic Spectrometry: Fundamentals and
Instrumentation Development
N2 - The almost-two-centuries history of spectrochemical analysis has generated a body of literature so vast that it has become nearly intractable for experts, much less for those wishing to enter the field. Authoritative, focused reviews help to address this problem but become so granular that the overall directions of the field are lost. This broader perspective can be provided partially by general overviews but then the thinking, experimental details, theoretical underpinnings and instrumental innovations of the original work must be sacrificed. In the present compilation, this dilemma is overcome by assembling the most impactful publications in the area of analytical atomic spectrometry. Each entry was proposed by at least one current expert in the field and supported by a narrative that justifies its inclusion. The entries were then assembled into a coherent sequence and returned to contributors for a round-robin review.
KW - Analytical atomic spectrometry
KW - Spectroscopy
KW - Instrumental analysis
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-621588
DO - https://doi.org/10.1177/00037028241263567
SN - 1943-3530
VL - 78
SP - 1
EP - 456
PB - Sage
CY - London
AN - OPUS4-62158
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Behnke, Thomas
A1 - Würth, Christian
A1 - Hoffmann, Katrin
A1 - Hübner, Martin
A1 - Panne, Ulrich
A1 - Resch-Genger, Ute
T1 - Encapsulation of hydrophobic dyes in polystyrene micro- and nanoparticles via swelling procedures
N2 - Aiming at the derivation of a generalized
procedure for the straightforward preparation of particles
fluorescing in the visible and near-infrared (NIR) spectral
region, different swelling procedures for the loading of the
hydrophobic polarity-probe Nile Red into nano- and
micrometer sized polystyrene particles were studied and
compared with respect to the optical properties of the
resulting particles. The effect of the amount of incorporated
dye on the spectroscopic properties of the particles was
investigated for differently sized beads with different
surface chemistries, i.e., non-functionalized, aminomodified
and PEG-grafted surfaces. Moreover, photostability
and leaking studies were performed. The main criterion
for the optimization of the dye loading procedures was a
high and thermally and photochemically stable fluorescence
output of the particles for the future application of these
systems as fluorescent labels.
KW - Fluorescence
KW - Nile red
KW - Polystyrene
KW - Nanoparticles
KW - Microparticles
KW - Encapsulation
KW - Swelling
PY - 2011
DO - https://doi.org/10.1007/s10895-010-0632-2
SN - 1053-0509
SN - 1573-4994
VL - 21
IS - 3
SP - 937
EP - 944
PB - Plenum Publ. Corp.
CY - New York, NY
AN - OPUS4-22692
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mair, Georg W.
A1 - Hoffmann, Martin
A1 - Saul, Herbert
A1 - Spode, Manfred
T1 - Betrachtung von Grenzwerten der Restfestigkeit von Composite-Druckgefäßen - Teil 2: Extrapolation der Lastwechsel-Degradation
N2 - Die aktuelle Praxis, auch die wiederkehrende Prüfung von Druckgefäßen aus Verbundwerkstoffen primär auf die hydraulische Innendruckprüfung abzustellen, ist sowohl im Hinblick auf die Schädigung der Prüfmuster als auch ihrer Aussagekraft kritisch zu bewerten. Daher bringt die BAM Bundesanstalt für Materialforschung und -prüfung zur Absicherung bei der Zulassung von Prüffristen für Composite-Druckgefäße, die älter als fünf Jahre sind, einen neuen Ansatz zur Anwendung. Er ermöglicht eine Zustandsbeschreibung der Population eines Baumusters auf der Basis wiederholt betriebsbegleitend zerstörender Prüfungen. Ein wesentlicher Aspekt dieses Ansatzes ist die Prognose der sicheren Restlebensdauer. Hierbei stellt der Effekt des übermäßigen Verlusts an hydraulischer Lastwechselfestigkeit im Sinne einer Degradation der Festigkeit einen kritischen Punkt in der Prognose der Sicherheit bis zum Lebensdauerende dar.
KW - Faserverbundwerkstoffe
KW - Druckgefäße
KW - Restfestigkeit
KW - Degradation
KW - Stichprobenprüfung
KW - Hydraulische Lastwechselprüfung
KW - Lebensdauer
KW - Überlebenswahrscheinlichkeit
KW - Lastwechselempfindlichkeit
PY - 2012
SN - 2191-0073
VL - 2
IS - 10
SP - 38
EP - 43
PB - Springer-VDI-Verl.
CY - Düsseldorf
AN - OPUS4-26672
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mair, Georg W.
A1 - Pöschko, Pascal
A1 - Hoffmann, Martin
A1 - Schoppa, André
A1 - Spode, Manfred
T1 - Betrachtung von Grenzwerten der Restfestigkeit von Composite-Druckgefäßen - Teil 1: Kriterien der hydraulischen Lastwechselprüfung
N2 - Die aktuelle Praxis, auch die wiederkehrende Prüfung von Druckgefäßen aus Verbundwerkstoffen primär auf die hydraulische Innendruckprüfung abzustellen, ist sowohl bezüglich der Schädigung der Prüfmuster als auch ihrer Aussagekraft als kritisch zu bewerten. Die Bundesanstalt für Materialforschung und -prüfung BAM bringt daher bei der Zulassung von Prüffristen für Composite-Druckgefäße von mehr als fünf Jahren zur Absicherung einen neuen Ansatz zur Anwendung. Er ermöglicht eine Zustandsbeschreibung der Population eines Baumusters auf der Basis wiederholt betriebsbegleitend zerstörender Prüfungen. Nachfolgend wird erläutert, wie die statistische Auswertung von Stichproben und deren perspektivische Extrapolation erfolgen und wie Zuverlässigkeitsgrenzwerte von der Größe von Druckgefäßen abhängig gemacht werden können, sowie welchen Einfluss der reale Gasdruck auf die Sicherheitsbewertung im Rahmen des Ansatzes der BAM hat. Insbesondere wird in das zentrale Arbeitsdiagramm des Ansatzes eingeführt und erläutert, wie dieses verwendet werden kann. Hierzu wird auch ausgeführt, wie die Füllzyklenzahl und die Lastwechselfestigkeit über die neu eingeführte Größe der spezifischen Füllempfindlichkeit zusammenhängen.
KW - Restfestigkeiten
KW - Degradation
KW - Betriebssicherheit
KW - Hydraulische Lastwechselprüfung
KW - Streuung
KW - Ausfallwahrscheinlichkeit
KW - Lastwechselempfindlichkeit
PY - 2012
SN - 2191-0073
VL - 2
IS - 7/8
SP - 30
EP - 38
PB - Springer-VDI-Verl.
CY - Düsseldorf
AN - OPUS4-26199
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gomes, Bruna F.
A1 - Prokop, Martin
A1 - Bystron, Tomas
A1 - Loukrakpam, Rameshwori
A1 - Melke, Julia
A1 - Lobo, Carlos M. S.
A1 - Fink, Michael
A1 - Zhu, Mengshu
A1 - Voloshina, Elena
A1 - Kutter, Maximilian
A1 - Hoffmann, Hendrik
A1 - Yusenko, Kirill V.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Röder, Bettina
A1 - Bouzek, Karel
A1 - Paulus, Beate
A1 - Roth, Christina
T1 - Following Adsorbed Intermediates on a Platinum Gas Diffusion Electrode in H3PO3-Containing Electrolytes Using In Situ X-ray Absorption Spectroscopy
N2 - One of the challenges of high-temperature polymer electrolyte membrane fuel cells is the poisoning of the Pt catalystwith H3PO4. H3PO4 is imbibed into the routinely used polybenzimidazole-based membranes, which facilitate Proton conductivity in the temperature range of 120−200 °C. However, when leached out of the membrane by water produced during operation, H3PO4 adsorbs on the Pt catalyst surface, blocking the active sites and hindering the oxygen reduction reaction (ORR).
The reduction of H3PO4 to H3PO3, which occurs at the anode due to a combination of a low potential and the presence of gaseous H2, has been investigated as an additional important contributing factor to the observed poisoning effect. H3PO3 has an affinity toward adsorption on Pt surfaces even greater than that of H2PO4 −. In this work, we investigated the poisoning effect of both H3PO3 and H3PO4 using a half-cell setup with a gas diffusion electrode under ambient conditions. By means of in situ X-ray absorption spectroscopy, it was possible to follow the signature of different species adsorbed on the Pt nanoparticle catalyst (H, O, H2PO4 −, and H3PO3) at different potentials under ORR conditions in various electrolytes (HClO4, H3PO4, and H3PO3). It was found that H3PO3 adsorbs in a pyramidal configuration P(OH)3 through a Pt−P bond. The competition between H3PO4 and H3PO3 adsorption was studied, which should allow for a better understanding of the catalyst poisoning mechanism and thus assist in the development of strategies to mitigate this phenomenon in the future by minimizing H3PO3 generation by, for example, improved catalyst design or adapted operation conditions or changes in the electrolyte composition.
KW - H3PO4 life cycle
KW - XAS
KW - In situ coupling
KW - High-temperature fuel cells
KW - H3PO3,
KW - Δμ XANES
PY - 2022
DO - https://doi.org/10.1021/acscatal.2c02630
SN - 2155-5435
VL - 12
IS - 18
SP - 11472
EP - 11484
PB - American Chemical Society (ACS)
AN - OPUS4-64733
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -