TY - CONF A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Kasparek, Eva Maria A1 - Völzke, Holger T1 - Modeling of cylindrical casks under horizontal drop test conditions N2 - Cylindrical casks made of ductile cast iron are used for transport, interim storage and final disposal of radioactive waste in Germany. A basic design criterion is the ability to withstand a horizontal drop without impact Binders onto a foundation representative for the real ground of a storage facility. The increasing use of more cost-effective material compositions requires optimized cask geometries to reduce stresses and strains in the cask structure. For example, a non-uniform wall thickness was introduced to reduce maximum wall bending stresses. As a result, the load characteristics changed from line load to point load at bottom and lid side under horizontal drop fest conditions. Hereby, the position of highest stress inside the structure has shifted significantly. This was the reason for a systematic investigation of effects caused by small design changes or small variations of fest conditions. It led to a better understanding of the positions of high local stresses, their time history and maximum value for cylindrical casks under horizontal drop test conditions. Hence, the paper presents the lessons learnt from modeling and simulating such scenarios considering an impact without limiters onto a realistic target. T2 - 14th International high-level radioactive waste management conference CY - Albuquerque, New Mexico, USA DA - 28.04.2013 KW - Cylindrical cask KW - Ductile cast iron KW - Numerical simulation KW - Horizontal drop test KW - Storage facility KW - Concrete foundation PY - 2013 SN - 978-1-62748-644-6 SP - 1114 EP - 1119 (Paper # 6862) PB - Omnipress AN - OPUS4-28529 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasparek, Eva Maria A1 - Völzke, Holger T1 - Further research on cask impact limiter needed? N2 - Transport and storage casks for medium and high level radioactive waste are subjected to extreme heavy loads during the accidental drop scenarios prescribed by IAEA regulations and national storage acceptance criteria. Subsequently, considerable efforts have been made to optimize impact limiting structures aiming to reduce cask stresses and deformations. Though, their benefits can only fully be exploited, if the energy absorbing behavior is reliable simulated by numerical models which play an increasingly important role in safety assessments. BAM has had conducted the 5-years research project ENREA in order to overcome the problems caused by the use of simplified, not sufficiently validated or even defective computational concepts for damping materials. While major results of the just recently completed program will be presented, the focus is laid on the question whether these Outputs provide a solid foundation for approximating impact limiting structures in all relevant configurations. So far, material models have been implemented for spruce, Polyurethane foams and damping concrete based mainly on small and medium scale compression test results. The experimental program performed at BAM comprised likewise guided drop tests and, especially for concrete, penetration tests. Although the resulting numerical simulations showed good agreement with measured values, it turned out to be necessary to consider further effects with regard to e.g. multiaxial stress States, shearfailures of shock absorbing components and their interaction with enclosed or enclosing structures. Thus, the strengths and application constraints of the actual models will be shown as well as details about further research needs, if any. T2 - RAMTRANSPORT 2015 - International conference on the radioactive materials transport and storage CY - Oxford, UK DA - 19.05.2015 KW - Numerical model KW - Shock absorber KW - Damping concrete KW - Polyurethane foam KW - Radioactive waste storage cask PY - 2015 SP - 1 EP - 8 AN - OPUS4-33992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheidemann, Robert A1 - Weber, Mike A1 - Völzke, Holger A1 - Kasparek, Eva Maria ED - Gomes, J.F.Silva ED - Meguid, S.A. T1 - Temperature dependendency of dynamically loaded polyurethane foam N2 - Polyurethane foam used as impact limiter material undergoes high plastic deformations, whereat the resulting stress-strain relations strongly depend on loading speed and temperature. This paper discusses the efforts necessary to develop a reliable numerical foam simulation model focussing on generation and implementation of temperature- dependent yield curves T2 - 6th International Conference on Mechanics and Materials in Design CY - Ponta Delgada, Azores, Portugal DA - 26.07.2015 KW - Impact limiter KW - Polyurethane foam KW - Finite element model KW - Strain rate KW - Temperature dependency PY - 2015 SN - 978-989-98832-3-9 SP - 1043 EP - 1046 PB - INEGI-FEUP AN - OPUS4-38889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasparek, Eva Maria A1 - Scheidemann, Robert A1 - Zencker, Uwe A1 - Wolff, Dietmar A1 - Völzke, Holger T1 - Effect of dynamic loading on compressional behavior of damping concrete N2 - In drop test scenarios related to assessing and licensing the storage procedure of spent fuel and high active waste, the casks under examination are generally not equipped with impact limiters. Hence, the extent of mechanical stresses in case of an assumed handling accident is largely affected by the ground properties of the reception hall floor in the specific storage facility. Unlike conventional brittle foundation materials, damping concrete performs quite well in such applications as it features high stiffness as well as high energy absorption due to the filler pore volume. However, its damping ability is not sufficiently exploited in current finite element (FE) calculations due to a lack of advanced material models for simulating its impact response. An implementation of qualified concepts that account for plastic, strain rate dependent behavior requires additional information that has to be provided by systematic test series. BAM recently started a research project to generate such data, subsequently to develop and to improve numerical methods for the analysis of impact limiters and damping foundation material and thus to optimize safety assessment tools for the design of transport and storage casks. A major part of this research concerns dynamic compression tests of variably shaped specimens conducted at a servo hydraulic 1MN impact testing machine as well as at a BAM facility for guided drop tests. This presentation focuses 100mm damping concrete cubes deformed vertically at constant rates under different constraint conditions. For example, a special fitting jig was constructed to subject the specimens to multi-axial loading. Thereby a deformation of 60% could be applied. Simulation was conducted by FE code ABAQUS™ based on material models “Concrete damaged plasticity” and “Crushable foam” which both allow defining rate sensitive nonlinear stress-strain relations in compression beyond the classic metal plasticity approach. T2 - PATRAM 2010 - 16th International symposium on the packaging and transport of radioactive materials CY - London, UK DA - 2010-10-03 KW - Damping concrete KW - Strain rate sensitivity KW - Numerical simulation KW - Material model PY - 2010 SP - 1-8 (Thursday-T40-114) AN - OPUS4-23708 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheidemann, Robert A1 - Kasparek, Eva Maria A1 - Qiao, Linan A1 - Müller, Karsten A1 - Droste, Bernhard A1 - Völzke, Holger T1 - Dynamic penetration tests on shock absorbing damping concrete T2 - WM2014 Conference CY - Phoenix, Arizona, USA DA - 2014-03-02 KW - Drop test KW - Dynamic KW - Penetration KW - Damping concrete PY - 2014 SN - 978-0-9836186-3-8 SP - Paper 14166, 1 EP - 9 AN - OPUS4-31948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan A1 - Kasparek, Eva Maria A1 - Völzke, Holger A1 - Zencker, Uwe A1 - Scheidemann, Robert T1 - Development of a finite element model for damping concrete under severe impact loads N2 - Finite element analysis (FEA) has been carried out for investigation of damping concrete under different impact loading conditions with a built-in material model and damage criteria available in FEA code ABAQUS. At first, all parameters for the selected material model had been derived from compression Tests of cubic specimens. After that, a validation was carried out with different static and dynamic penetration tests. Finally, a 5 meter real drop test with a 23 Mg cylindrical cask could successfully be simulated. T2 - PATRAM 2013 - 17th International symposium on the packaging and transportation of radioactive materials CY - San Francisco, CA, USA DA - 18.08.2013 PY - 2013 SP - Session D, Paper 127, 1 EP - 10 PB - Omnipress AN - OPUS4-29110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasparek, Eva Maria A1 - Völzke, Holger A1 - Scheidemann, Robert A1 - Zencker, Uwe T1 - Numerical and experimental investigations of polyurethane foam for use as cask impact limiter in accidental drop scenarios T2 - WM2012 - Waste management conference CY - Phoenix, AZ, USA DA - 2012-02-26 KW - Plasticity KW - Finite elements KW - Material models KW - Rate dependency KW - Temperature dependency KW - Compression tests KW - Drop tests KW - Parameter identification PY - 2012 SN - 978-0-9836186-1-4 N1 - Serientitel: WM Symposia – Series title: WM Symposia IS - Paper 12099 SP - 1 EP - 9 AN - OPUS4-26270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kasparek, Eva Maria A1 - Völzke, Holger A1 - Scheidemann, Robert A1 - Zencker, Uwe A1 - Wolff, Dietmar T1 - Experimental and numerical studies of shock absorbing materials for containers for radioactive waste PY - 2012 SN - 1431-5254 VL - 57 IS - 6 SP - 397 EP - 401 PB - Inforum CY - Berlin AN - OPUS4-26261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisenacher, Germar A1 - Scheidemann, Robert A1 - Neumann, Martin A1 - Sterthaus, Jens A1 - Kasparek, Eva Maria A1 - Völzke, Holger T1 - Stauchversuche mit querdehnungsbehinderten Fichtenholzproben verschiedener Faserorientierungen bei veränderlicher Dehnrate T1 - Compression tests with laterally constrained spruce specimens with varying fiber orientations and loading rates N2 - Im Zuge des Forschungsvorhabens ENREA (Entwicklung rechnerischer Analysemethoden für stoßdämpfende Strukturen beim Anprall oder Absturz von Abfallgebinden) führt die BAM systematische Untersuchungen an stoßdämpfenden Werkstoffen, unter anderem an Fichtenholz, durch. Zweck der mit diesen Untersuchungen erzeugten Datenbasis ist die Erstellung und Parametrierung eines Finite-Elemente- (FE-) Materialmodells, das die Modellierung holzgefüllter stoßdämpfender Bauteile von Transportbehältern für radioaktive Stoffe in der FE-Simulation ermöglichen soll. Anhand von Ergebnissen aus der ersten Versuchsphase werden der Einfluss der Dehnrate und der Faserorientierung auf das Kraft-Verformungs-Verhalten von Fichtenholz diskutiert. Anschließend wird die rechnerische Modellierung von Fichtenholz diskutiert und die Anforderungen an ein Materialmodell werden erläutert. N2 - In the course of research project ENREA (development of numerical methods for analyzing impact limiters subjected to impact or drop scenarios), BAM is systematically investigating impact limiting materials, e. g. spruce wood. Goal of these investigations is to establish and parameterize a finite element (FE) material model which enables the modeling of wood filled impact limiting devices of transport casks for radioactive materials. Using results of the first test stage, the effect of loading rate and fiber orientation on the force-deflection characteristics of spruce wood will be presented. Following, computational modeling of spruce wood including requirements for a material model will be discussed. T2 - KONTEC 2011 - 10. Internationales Symposium "Konditionierung radioaktiver Betriebs- und Stilllegungsabfälle" CY - Dresden, Germany DA - 06.04.2011 PY - 2011 N1 - Sprachen: Deutsch/Englisch - Languages: German/English SP - 465 EP - 478 AN - OPUS4-23684 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasparek, Eva Maria A1 - Scheidemann, Robert A1 - Wolff, Dietmar A1 - Zencker, Uwe A1 - Völzke, Holger T1 - Untersuchungen zum Verhalten von Dämpferbeton unter Stossbelastung N2 - Während des Transportes sind Behälter für hoch radioaktive Abfälle durch stoßdämpfende Bauteile vor Einwirkungen, die aus Unfallszenarien gemäß den IAEA Regularien resultieren können, weitestgehend geschützt. Nach dem Entfernen dieser Komponenten im Rahmen der Einlagerung ins Zwischenlager müssen Vorkehrungen getroffen sein, um Beanspruchungen der Behälter aus möglichen Handhabungsunfällen im Empfangsbereich zu reduzieren. Die Maßnahmen müssen vor allem darauf abzielen, die stoßdämpfenden Eigenschaften der potentiellen Aufprallflächen zu optimieren. Da Standardmaterialien für Fundamente nur ein geringes Energieabsorptionsvermögen aufweisen, wurde durch die Firma HOCHTIEF eine neuartige Betonmixtur entwickelt, bei der ein spezieller Leichtzuschlag zum Einsatz kommen. Zur Charakterisierung dieses sogenannten Dämpferbetons liegen Standardkennwerte vor sowie Messwerte aus Eindringversuchen, die zur Qualitätssicherung für jede Produktcharge durchgeführt werden. Das stoßdämpfende Potential des neuen Werkstoffs kann jedoch nur dann vollkommen ausgeschöpft werden, wenn die Energieabsorption in numerischen Simulationen der Behälterabstürze über die gesamte Belastungsdauer zuverlässig wiedergegeben wird. Für die Implementierung und Anpassung eines entsprechenden Materialmodelis in einem Finite Elemente (FE) Programm sind Daten aus systematischen Druckversuchen mit Variation der relevanten Einflussgrößen erforderlich. An der BAM werden daher im Rahmen eines werkstoffübergreifenden Forschungsvorhabens zur Untersuchung von stoßdämpfenden Strukturen auch die Eigenschaften von Dämpferbeton experimentell untersucht und zugehörige numerische Methoden entwickelt. Der aktuelle Beitrag behandelt die Ergebnisse der ersten Projektphase, in der kubische Probekörper mit der Kantenlänge 100mm bei unterschiedlichen Lagerungsbedingungen statisch und dynamisch gestaucht wurden. In nachfolgenden Versuchen wird der Einfluß der Probengröße ermittelt sowie die Eignung der verwendeten Materialmodelle anhand realistischer Belastungssituationen validiert. Versuchsprogramm. T2 - Jahrestagung Kerntechnik 2011 CY - Berlin, Germany DA - 17.05.2011 KW - Stoßdämpfende Werkstoffe KW - Materialmodellierung KW - Versuchsprogramm KW - Stoßbelastung KW - Dehnratenabhängigkeit KW - Temperaturabhängigkeit KW - Polyurethan Schaum KW - Dämpferbeton PY - 2011 IS - Session TS-17 / Paper 171 SP - 1 EP - 5 AN - OPUS4-23836 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -