TY - CONF A1 - Weber, Mike A1 - Völzke, Holger A1 - Zencker, Uwe T1 - Influence of dense near-surface reinforcement layers in concrete slabs of test stand foundatins T2 - RAMTRANSPORT 2012 CY - London, England DA - 2012-05-22 PY - 2012 AN - OPUS4-25961 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Komann, Steffen A1 - Kiyak, Yusuf A1 - Wille, Frank A1 - Zerbst, Uwe A1 - Weber, Mike A1 - Klingbeil, Dietmar T1 - Assessment of ductile cast iron fracture mechanics analysis within licensing of German transport packages T2 - ASME 2012 Pressure vessels & piping division conference CY - Toronto, Ontario, Canada DA - 2012-07-15 PY - 2012 SP - PVP2012-78213, 1-7 PB - American Society of Mechanical Engineers CY - New York AN - OPUS4-26363 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Komann, Steffen A1 - Kiyak, Yusuf A1 - Wille, Frank A1 - Zerbst, Uwe A1 - Weber, Mike A1 - Klingbeil, Dietmar T1 - Assessment of ductile cast iron fracture mechanics analysis within licensing of German transport packages N2 - In the approval procedure of transport packages for radioactive materials, the mechanical and thermal safety assessment is carried out in Germany by competent authority BAM. In recent years BAM was involved in several licensing procedures of new spent fuel and HLW package designs, where the cask body was made of Ductile Cast Iron (DCI). According to IAEA regulations package designs have to fulfill requirements for specific conditions of transport. Type B(U) packages must withstand the defined accident conditions of transport. The temperature range from -40°C up to the operational temperature has to be considered. For the cask material DCI, it is necessary to determine the brittle fracture behavior. The German guideline BAM-GGR 007 defines requirements for the fracture mechanics of DCI. Due to complex structure of the cask body and the dynamic loading a fracture mechanical assessment in an analytical kind is not always possible. Experience of recent design approval procedures show that the application of numerical calculations are applicable to determine the fracture mechanical load in the cask body. At the first step a numerical analysis has to be done to identify the loading state at the whole cask body. Secondly an analysis of a detail of the cask body is made considering the displacement boundary conditions of the global model. An artificial flaw is considered in this detailed model to calculate the fracture mechanical loading state. The finite element mesh was strongly refined in the area of flaw. The size of the artificial flaw is characterized by the ultrasonic inspection used for the quality assurance of the package. The applicant developed additional analysis tools for calculation of stress intensity factor and/or J-Integral. The assessment approach by BAM led to the decision to develop own tools to the possibility for independent check of the results. The paper describes the authority assessment approach for the DCI fracture mechanics analysis. The validation procedure incl. the development of own tools is explained. BAM developed a post-processor called JINFEM to determine the fracture mechanical loads. The regulatory 1 m puncture bar drop test is used to give an example of the assessment procedure. T2 - 52nd INMM Annual meeting CY - Palm Desert, CA, USA DA - 17.07.2011 KW - Mechanische Bewertung KW - Radioaktives Material KW - Numerische Analyse KW - Bruchmechanik PY - 2011 SP - 1 EP - 10 AN - OPUS4-25022 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Weber, Mike A1 - Kovacs, Oliver A1 - Droste, Bernhard T1 - Application limits of low-ductile cast iron for radioactive waste containers T2 - PATRAM 2007, 15th International Symposium on the Packaging and Transportation of Radioactive Materials CY - Miami, Florida, USA DA - 2007-10-21 KW - Ductile iron KW - Container design KW - Safety assessment KW - Fracture mechanics KW - Dynamic loading conditions PY - 2007 IS - Session B, Paper #97 SP - 1 EP - 8 PB - Institute of Nuclear Materials Management AN - OPUS4-18399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Weber, Mike A1 - Kovacs, Oliver A1 - Droste, Bernhard T1 - Sicherheitstechnische Analyse von Transport- und Lagerbehältern aus Gusseisen mit erhöhten metallischen Reststoffanteilen mittels Fallversuchen T2 - KONTEC 2007 CY - Dresden, Deutschland DA - 2007-03-21 KW - Behälterdesign KW - Bruchmechanik KW - Duktiles Gusseisen KW - Dynamische Belastungsbedingungen KW - Sicherheitstechnische Bewertung PY - 2007 SP - 869 EP - 875 PB - Gesellschaft für technische Kommunikation mbH / Kerntechnische Gesellschaft CY - Dresden AN - OPUS4-14712 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Zencker, Uwe A1 - Wolff, Dietmar A1 - Völzke, Holger A1 - Herbrich, Uwe A1 - Nagelschmidt, Sven T1 - Numerical Analysis of Cask Accident Scenarios in Storage Facilities T2 - 17th International Symposium on Packaging and Transportation of Radioactive Materials (PATRAM) 2013 CY - San Francisco, CA, USA DA - 2013-08-18 PY - 2013 AN - OPUS4-29380 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Wille, Frank A1 - Ballheimer, Viktor A1 - Musolff, André T1 - Numerische Analyse der 1-m-Fallprüfung auf einen Stahldorn T2 - Jahrestagung Kerntechnik 2010 CY - Berlin, Deutschland DA - 2010-05-04 KW - IAEO KW - 1-m-Fallprüfung KW - Stahldorn KW - Numerische Analyse KW - Verifizierung PY - 2010 IS - Sektion 5 / 505 SP - 1 EP - 5 CY - Berlin AN - OPUS4-21292 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Wille, Frank A1 - Ballheimer, Viktor A1 - Musolff, André T1 - Numerische Analyse der 1-m-Fallprüfung auf einen Stahldorn T2 - Jahrestagung Kerntechnik 2010 CY - Berlin, Germany DA - 2010-05-04 PY - 2010 AN - OPUS4-21260 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Komann, Steffen A1 - Neumann, Martin A1 - Ballheimer, Viktor A1 - Wille, Frank A1 - Weber, Mike A1 - Qiao, Linan A1 - Droste, Bernhard T1 - Static and dynamic calculation approaches for mechanical design assessment of type B packages for radioactive material transport - 10193 T2 - WM2010 Conference CY - Phoenix, Arizona, USA DA - 2010-03-07 KW - Mechanische Bewertung KW - Radioaktives Material KW - Numerische Analyse KW - Typ B(U)-Verpackung PY - 2010 SP - 1 EP - 9 AN - OPUS4-21240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Wille, Frank A1 - Ballheimer, Viktor A1 - Musolff, André T1 - From Experiment to an Appropriate Finite Element Model - Safety Assessment for Ductile Cast Iron Casks Demonstrated by means of IAEA Puncture Drop Test T2 - PATRAM 2010 (16th Internationl Symposium on the Packaging and Transport of Radioactive Material) CY - London, England DA - 2010-10-03 PY - 2010 AN - OPUS4-22241 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Weber, Mike A1 - Wille, Frank T1 - Finite element mesh design of a cylindrical cask under puncture drop test conditions N2 - Transport casks for radioactive materials have to withstand the 9 m drop test, 1 m puncture drop test and dynamic crush test with regard to the mechanical requirements according to the IAEA regulations. The safety assessment of the package can be carried out on the basis of experimental investigations with prototypes or models of appropriate scale, calculations, by reference to previous satisfactory safety demonstrations of a sufficiently similar nature or a combination of these methods. Computational methods are increasingly used for the assessment of mechanical test scenarios. However, it must be guaranteed that the calculation methods provide reliable results. Important quality assurance measures at BAM are given concerning the preparation, run and evaluation of a numerical analysis with reference to the appropriate guidelines. Hence, a successful application of the finite element method requires a suitable mesh. An analysis of the 1 m puncture drop test using successively refined finite element meshes was performed to find an acceptable mesh size and to study the mesh convergence using explicit dynamic finite element codes. The finite element model of the cask structure and the puncture bar is described. At the beginning a coarse mesh was created. Then this mesh was refined in two steps. In each step the size of the elements was bisected. The deformation of the mesh and the stresses were evaluated dependent on the mesh size. Finally, the results were extrapolated to an infinite fine mesh or the continuous body, respectively. The uncertainty of the numerical solution due to the discretization of the continuous problem is given. A safety factor is discussed to account for the uncertainty. The calculation results are compared with experimental data from a puncture drop test with a half-scale model of a cylindrical cask. This paper supports the convergence studies of the Task Group on Computational Modeling for Explicit Dynamics reporting to the ASME BPV Code Working Group on Design Methodology. T2 - PATRAM 2010 - 16th International symposium on the packaging and transport of radioactive materials CY - London, UK DA - 2010-10-03 KW - IAEA puncture drop test KW - Numerical analysis KW - Verification KW - Explicit dynamics PY - 2010 SP - 1 EP - 8 (Session T45 / Paper 219) AN - OPUS4-23843 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neser, A. A1 - Schreiber, D. A1 - Magallanes, J. A1 - Martinez, R. A1 - Zencker, Uwe A1 - Weber, Mike T1 - A material testing program to characterize the concrete behavior under static and dynamic loads N2 - In this paper a comprehensive material testing program is described to characterize a German final repository concrete material (BERB1) subjected to static and dynamic loads. The BERB1 material was developed und specified by the German Bundesanstalt für Materialforschung und -prüfung (BAM) for targets used for drop tests according to the KONRAD requirements. The testing consists of three concurrent laboratory experimental programs performed in the USA. An extensive preliminary testing program in Germany was performed to assure the required concrete specifications during fabrication and curing. The first set of data is the static basic material test program consisting of structural tests to quantify macroscopic concrete properties under quasi-static loads. Cubic and cylindrical specimens are investigated under this effort. The second set of test data is from the static complete material test program, where cylindrical concrete specimens are subjected to a variety of quasi-static axial and radial stress and strain paths using a high-pressure hydraulic tri-axial chamber. The material is characterized for confining pressures up to 400 MPa. The third set of data is from the dynamic complete material test program, which uses a modified Split-Hopkinson Pressure Bar to induce dynamic compression and tension waves into cylindrical concrete specimens that generate strain-rates up to 400 s-1. The ensemble of data generated in these experiments provides a complete set of data that effectively describes the behavior of this concrete and can be used to develop a constitutive calculation model. In addition, the results of the tests show a significant effect of moisture on the strength and rheology of this concrete for quasi-static pressures greater than 50 MPa. Numerical drop test simulations with the developed constitutive model in the Lagrangian finite element code, LS-DYNA, show good agreement with the experimental results from a BAM research project. T2 - PATRAM 2010 - 16th International symposium on the packaging and transport of radioactive materials CY - London, UK DA - 2010-10-03 KW - Testing program KW - Concrete behavior KW - Static loads KW - Dynamic loads KW - KONRAD acceptance criteria KW - Ductile cast iron cask PY - 2010 SP - 1 EP - 8 (Session T40 / Paper 123) AN - OPUS4-23845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weber, Mike A1 - Wille, Frank A1 - Ballheimer, Viktor A1 - Musolff, André T1 - From experiment to appropriate finite element model-safety assessment for ductile cast iron casks demonstrated by means of IAEA puncture drop test N2 - In the approval procedure of transport packages for radioactive materials, the competent authority mechanical and thermal safety assessment is carried out in Germany by BAM Federal Institute for Materials Research and Testing. The combination of experimental investigations and numerical calculations in conjunction with materials and components testing is the basis of the safety assessment concept of the BAM. Among other mechanical test scenarios, a 1 metre drop test onto a steel bar has to be considered for the application of the hypothetical accident conditions to Type B packages according to IAEA regulations. Within the approval procedure for the new German package design of the HLW cask CASTOR® HAW 28M, designed by GNS Gesellschaft für Nuklear-Service Germany, a puncture drop test was performed with a half-scale model of the cask at -40°C. For independent assessment and to control the safety analysis presented by the applicant, BAM developed a complex finite element (FE) model for a dynamical ABAQUS/ExplicitTM analysis. This paper describes in detail the use of the FE method for modelling the puncture drop test within an actual assessment strategy. At first, investigations of the behaviour of the steel bar were carried out. Different friction coefficients and the material law of the bar were analysed by using a 'rigid-body' approximation for the cask body. In the next step, a more detailed FE model with a more realistic material definition for the cask body was developed. The validation of calculated strains was carried out by comparison with the results of the strain gauges located at the relevant points of the cask model. The influence of the FE meshing is described. Finally, the validated FE half-scale model was expanded to full-scale dimension. Scaling effects were analysed. The model was used for safety assessment of the package to be approved. KW - IAEA puncture drop test KW - Cylindrical cask KW - Explicit dynamics KW - Scaled model KW - Numerical analysis KW - Validation KW - Safety assessment PY - 2011 DO - https://doi.org/10.1179/1746510911Y.0000000010 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 22 IS - 3 SP - 148 EP - 153 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-25356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Komann, Steffen A1 - Neumann, Martin A1 - Ballheimer, Viktor A1 - Wille, Frank A1 - Weber, Mike A1 - Qiao, Linan A1 - Droste, Bernhard T1 - Mechanical assessment within type B packages approval: application of static and dynamic calculation approaches N2 - This paper demonstrates exemplarily how numerical and experimental approaches can be combined reasonably in mechanical assessment of package integrity according to the IAEA regulations. The paper also concentrates on the question about how static mechanical approaches can be applied, and what their problems are in relation to dynamic calculation approaches. Under defined impact tests, which represent accident transport conditions, the package has to withstand impact loading, e.g. resulting from a 9 m free drop onto an unyielding target in sequence with a 1 m puncture drop test. Owing to the local character of the interaction between the puncture bar and the cask body, it is possible to develop a dynamic numerical model for the 1 m puncture drop which allows an appropriate simulation of the interaction area. Results from existing experimental drop tests with prototype or small scale cask models can be used for verification and validation of applied analysis codes and models. The link between analysis and experimental drop testing is described exemplarily by considering a regulatory 1 m puncture bar drop test onto the cask body of a recently approved German high level waste transport package. For the 9 m drop test of the package, it is difficult to develop a dynamic numerical model of the package due to the complexity of the interaction between cask body, impact limiters and unyielding target. Dynamic calculations require an extensive verification with experimental results. The simulation of a 9 m drop of a package with impact limiters is thereby often more complex than the simulation of a 1 m puncture drop onto the cask body. A different approximation method can be applied for the consideration of dynamic effects on the impact loading of the package. In a first step, maximum impact force and rigid body deceleration of the cask body during the impact process can be calculated with simplified numerical tools. This rigid body deceleration can subsequently be applied on a verified static numerical model. Dynamic effects, which cannot be covered by the static numerical analysis, have therefore to be considered by using an additional dynamic factor. The paper describes this approach exemplarily for a 9 m horizontal drop of a typical spent fuel cask design. KW - Package assessment KW - Package KW - Packaging KW - Structural analysis PY - 2011 DO - https://doi.org/10.1179/1746510911Y.0000000012 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 22 IS - 4 SP - 179 EP - 183 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-26448 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Komann, Steffen A1 - Kiyak, Yusuf A1 - Wille, Frank A1 - Zerbst, Uwe A1 - Weber, Mike A1 - Klingbeil, Dietmar T1 - Assessment of ductile cast iron fracture mechanics analysis within licensing of German transport packages N2 - In the design approval of transport packages for radioactive materials, the mechanical and thermal safety assessment is carried out in Germany by competent authority BAM. In recent years BAM was involved in several licensing procedures of new spent fuel and HLW package designs, where the cask body is of Ductile Cast Iron (DCI). According to IAEA regulations package designs have to fulfill requirements for specific conditions of transport. Type B(U) packages must withstand the defined accident conditions of transport. The temperature range from -40°C up to the operational temperature has to be considered. For the cask material DCI, it is necessary to determine safety against brittle fracture. The German guideline BAM-GGR 007 defines requirements for fracture mechanics of packagings made of DCI. Due to complex cask body structure and the dynamic loading a fracture mechanical assessment by analytical approaches is not always possible. Experience of recent design approval procedures show that the application of numerical calculations are applicable to determine the stresses and stress intensity factors in the cask body. At the first step a numerical analysis has to be done to identify the loading state at the whole cask body. Secondly an analysis of a detail of the cask body is made considering the displacement boundary conditions of the global model. An artificial flaw is considered in this detailed model to calculate the fracture mechanical loading state. The finite element mesh was strongly refined in the area of the flaw. The size of the artificial flaw is based on the ultrasonic inspection acceptance criteria applied for cask body manufacture. The applicant (GNS) developed additional analysis tools for calculation of stress intensity factor and/or J-Integral. The assessment approach by BAM led to the decision to develop own tools to the possibility for independent proof of the results. The paper describes the authority assessment approach for DCI fracture mechanics analysis. The validation procedure incl. the development of own tools is explained. BAM developed a postprocessor to determine the fracture mechanical loads. A horizontal 1 m puncture bar drop test is used to give a detailed description of the assessment procedure. 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 - 1 EP - 10 PB - Omnipress AN - OPUS4-30175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Zaghdoudi, Maha A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - A numerical approach to correlate compression stress relaxation and compression set of elastomer O-rings with tightness N2 - The excellent mechanical properties of elastomer seals at a wide range of temperatures as well as their high versatility and recovery potential under several load conditions make these materials well suitable for the application in containers designed for transport and disposal of negligible heat generating radioactive 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 which prohibit an avoidable cask handling. An extensive knowledge of the change of the elastomer properties during aging and the availability of reliable end-of-lifetime criteria to guarantee the safe enclosure of the radioactive material for the required time are 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 already been made and are still ongoing to scientifically support this task. Among other representative types of elastomers, specimen made from ethylene propylene diene rubber (EPDM) were tested before, during and after aging to capture the with respect to application most important of their complex mechanical properties. Exemplary results of these investigations were used to calibrate material models implemented in the commercial finite element software ABAQUS/Standard®. The finite element model already presented in previous works uses a sequential temperature displacement coupling. The calculated compression stress relaxation (CSR) and compression set (CS) values do satisfactorily match the experimental results. In many investigations performed at BAM both values (CSR and CS) were identified as key indicators of elastomer’s long-term performance. However, the possibility to correlate these equivalent indicators with performance values such as tightness and leakage rate, measurable in the mounted state, is an important goal of our future work. In the presented study the ABAQUS® feature of “pressure penetration” is introduced in the suggested finite element model for this purpose. It provides the possibility to simulate the penetration of a gas into a possible gap between flange and O-ring causing an opening of a leakage path. Three dimensional and axis-symmetric finite element models were generated to represent flat and grooved flanges of different dimensions. The sensitivity of the feature to several input parameters is investigated and the observed behavior of the O-ring is correlated with the results of performed leakage tests. T2 - ASME 2021 Pressure Vessels & Piping Conference (PVP2021) CY - Online meeting DA - 13.07.2021 KW - Elastomer KW - Tightness KW - Leakage KW - Compression set KW - Compression stress relaxation PY - 2021 SN - 978-0-7918-8535-2 DO - https://doi.org/10.1115/PVP2021-61976 SP - 1 EP - 8 PB - American Society of Mechanical Engineers (ASME) CY - New York, NY, USA AN - OPUS4-54422 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Zaghdoudi, Maha A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - A numerical approach to correlate compression stress relaxation and compression set of elastomer O-rings with tightness N2 - The excellent mechanical properties of elastomer seals at a wide range of temperatures as well as their high versatility and recovery potential under several load conditions make these materials well suitable for the application in containers designed for transport and disposal of negligible heat generating radioactive 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 which prohibit an avoidable cask handling. An extensive knowledge of the change of the elastomer properties during aging and the availability of reliable end-of-lifetime criteria to guarantee the safe enclosure of the radioactive material for the required time are 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 already been made and are still ongoing to scientifically support this task. Among other representative types of elastomers, specimen made from ethylene propylene diene rubber (EPDM) were tested before, during and after aging to capture the with respect to application most important of their complex mechanical properties. Exemplary results of these investigations were used to calibrate material models implemented in the commercial finite element software ABAQUS/Standard®. The finite element model already presented in previous works uses a sequential temperature displacement coupling. The calculated compression stress relaxation (CSR) and compression set (CS) values do satisfactorily match the experimental results. In many investigations performed at BAM both values (CSR and CS) were identified as key indicators of elastomer’s long-term performance. However, the possibility to correlate these equivalent indicators with performance values such as tightness and leakage rate, measurable in the mounted state, is an important goal of our future work. In the presented study the ABAQUS® feature of “pressure penetration” is introduced in the suggested finite element model for this purpose. It provides the possibility to simulate the penetration of a gas into a possible gap between flange and O-ring causing an opening of a leakage path. Three dimensional and axis-symmetric finite element models were generated to represent flat and grooved flanges of different dimensions. The sensitivity of the feature to several input parameters is investigated and the observed behavior of the O-ring is correlated with the results of performed leakage tests. T2 - ASME 2021 Pressure Vessels & Piping Conference (PVP2021) CY - Online meeting DA - 13.07.2021 KW - Elastomer KW - Tightness KW - Leakage KW - Compression set KW - Compression stress relaxation PY - 2021 AN - OPUS4-54423 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Völzke, Holger A1 - Zencker, Uwe A1 - Hauer, Katharina A1 - Herz, A. A1 - Kreienmeyer, M. T1 - Aufbau eines Aufprallfundamentes mit reproduzierbaren Eigenschaften für Baumusterprüfungen von Abfallbehältern für das Endlager Konrad N2 - Abgeleitet aus den in Teil 3 der „Systemanalyse Konrad“ definierten Lastannahmen für den „untertägigen Anlagenbereich“ müssen Verpackungen, die der Abfallbehälterklasse I (ABK I) mit dem zusätzlichen Merkmal der störfallfesten (sf) Verpackung oder der ABK II zugeordnet werden, gemäß den „Endlagerungsbedingungen, Endlager Konrad“, nach einem „…Fall aus 5 m Höhe auf eine unnachgiebige Unterlage…“ bestimmten Anforderungen genügen. Eine nähere Beschreibung der Prüfeinrichtung sowie die Definition detaillierter Anforderungen an das Aufprallfundament erfolgen in der „Produktkontrolle, Endlager Konrad“: „Die Prüfeinrichtung, bestehend aus einer Hebeeinrichtung und einem Fundament ist so zu gestalten, dass der Fall des Prüfmusters in jeder beliebigen Aufprallorientierung aus 5 m Höhe, gemessen von der Unterkante des Prüfmusters zum Fundament, möglich ist. Das Fundament ist aus Beton der Mindestgüte B 35 herzustellen und muss so beschaffen und verankert sein, dass keine Zerstörung in zahlreiche kleinere Bruchstücke erfolgt und keine horizontale Verschiebung des Fundamentes oder seiner Teile auftritt. Maße und Masse des Fundaments müssen so beschaffen sein, dass der Einfluss des Baugrundes unter dem Fundament auf den Aufprallwiderstand vernachlässigbar ist.“ Im Rahmen der Bauartprüfung für Behälter zur Endlagerung radioaktiver Abfälle mit zu vernachlässigender Wärmeentwicklung im Endlager Konrad wird die Bundesanstalt für Materialforschung und -prüfung (BAM) von der Bundesgesellschaft für Endlagerung (BGE) als Sachverständige hinzugezogen und ist in der Regel auch mit der Durchführung der notwendigen Fallprüfungen auf dem Testgelände Technische Sicherheit der BAM (BAM TTS) einschließlich der Bereitstellung der benötigten Prüfeinrichtungen sowie des regelkonformen Aufprallfundamentes beauftragt. Der Prozess, beginnend von der Gewährleistung einer von allen Beteiligten als gültig bewerteten Fallprüfung bis hin zur abschließenden Bewertung und Interpretation der Versuchsergebnisse erfordert dabei u.a. eine sorgfältige Planung und Fertigung der für das Endlager Konrad repräsentativen Fundamentplatte und deren Ankopplung an einen Untergrund im Sinne der „Regulations for the Safe Transport of Radioactive Material“ wie er zum Beispiel auf den beiden Fallversuchsanlagen des BAM Testgelände Technische Sicherheit (BAM TTS) zur Verfügung steht. Um diese Anforderungen zu erfüllen muss zum einen der Erhalt der Integrität der Fundamentplatte beim Fallversuch durch eine geeignete Auswahl und kraftflussgerechte Anordnung der Stabstahl-Bewehrung sowie deren Verankerung garantiert und damit eine unzulässige Energieaufnahme durch Risse sowie eine unzulässige „… Zerstörung (der Fundamentplatte) in zahlreiche kleinere Bruchstücke …“, wie in [3] gefordert, verhindert werden. Außerdem ist zu gewährleisten, dass der Beton die Anforderungen an die vorgeschriebene Mindestgüte bzw. -festigkeit zum Zeitpunkt der Fallprüfung erfüllt, die Betonfestigkeit jedoch zur Vermeidung unnötig verschärfter Prüfrandbedingungen eine zu definierende Obergrenze nicht überschreitet. Ausgehend von dem 2009 im Rahmen der KONTEC veröffentlichten Wissensstand präsentiert die BAM im vorliegenden Beitrag die wesentlichen Ergebnisse der zwischenzeitlich bei der Planung und Durchführung von zahlreichen Fallprüfungen gewonnenen Erfahrungen bzgl. Spezifikation und Fertigung der für die Fallversuche notwendigen Fundamentplatten sowie deren Anbindung an den Untergrund. Neben den immer wieder notwendigen Anstrengungen zur Gewährleistung einer im Rahmen der Definition korrekten Betondruckfestigkeit am Tag der Fallprüfung wird die Anpassung der Bewehrungsführung an verschiedene Fallpositionen diskutiert. Zur Ergänzung des gültigen Regelwerks entsteht parallel zu diesem Dokument eine Fachnotiz, in der BGE und BAM die Vorgaben und Spezifikationen zur regelwerkskonformen Herstellung und Montage von Fundamentplatten für Fallprüfungen im Rahmen der Behälterbauartprüfungsverfahren für das Endlager Konrad zusammenfassen und veröffentlichen werden. Diese Fachnotiz soll detaillierte Vorgaben und Spezifikationen zur Planung, Beauftragung, Herstellung und abschließenden Prüfung eines solchen Fundamentes und dessen Anbindung an den Untergrund enthalten. Damit soll allen beteiligten Organisationen wie Antragstellern, Sachverständigen und BGE ein langfristig verlässlicher Leitfaden im Hinblick auf die Durchführung anforderungsgerechter Fallprüfungen unter definierten und reproduzierbaren Randbedingungen im Rahmen der Bauartprüfungsverfahren für das Endlager Konrad an die Hand gegeben werden. T2 - KONTEC 2021 CY - Dresden, Germany DA - 25.08.2021 KW - Aufprallfundament KW - Endlager Konrad KW - Fallprüfung PY - 2021 SP - 1 EP - 10 CY - Dresden AN - OPUS4-53372 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Zaghdoudi, Maha A1 - Brandt, Guido A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Coefficients of Friction in Dependence on Aging State of Elastomers – Experimental Identification and Numerical Simulation of the Experiment N2 - Elastomer seals are mounted as barrier seals in lid systems of containers designed for transport and disposal of negligible heat generating radioactive waste and as auxiliary seals in spent fuel storage and transportation casks (dual purpose casks (DPC)). When the behavior of mounted seals under normal and hypothetical accident conditions of disposal and transport is to be simulated, a comprehensive knowledge of their complex mechanical properties at every state of aging is necessary. In previous works, BAM’s efforts in experimental investigations on specimen artificially aged at different temperatures and times and the implementation of the found results in finite element material models were presented. Additionally, our approaches to reproduce the aging process itself and to extrapolate the results of artificially accelerated aging to longer times were presented. Numerical simulations have shown that the behavior of the seal during mounting and one-sided pressurizing and the resulting performance values such as leakage rate strongly depend on the coefficient of friction (COF) between flange and seal. The friction coefficient, in turn, depends on the aging state of the elastomer material as several publications suggest (see below). Dynamic COF between an exemplary ethylene propylene diene rubber (EPDM) material and a stainless steel ball were determined by using a self-designed linear oscillation tribometer. Unaged and artificially aged EPDM specimen stored for 30 days and 100 days at a temperature of 150 °C were tested. A stainless steel ball (d=10 mm) is brought in contact with the specimen’s surface und loaded by normal forces of 2.5 N, 5 N, 10 N and 20 N. During a reciprocating movement of the EPDM sheet, the horizontal force/friction force is continuously measured, and the COF can be derived. It is well known that friction is a complex phenomenon especially in soft materials. It cannot be excluded that the measured friction force is influenced by additional force components, resulting from the ball’s grooving through the elastomer’s surface. This force depends on the penetration depth of the ball and on the resistance of the elastomer in its different states of aging. The latter results from microstructural changes i.e., chain scission and additional crosslinking that occur during aging which in turn influence the softening or hardening of the material. A finite element (FE) ABAQUS® model was developed to reproduce the measurement process. It should help to better understand the physical mechanisms and to quantify the percentage of measured forces resulting from real friction on the one hand and forces resulting from unintended side effects that could falsify the result on the other hand. The behavior of the elastomer in its different states of aging is reproduced by a FE material model already presented in previous works of BAM. T2 - ASME 2022 Pressure Vessels & Piping Conference (PVP2022) CY - Las Vegas, NV, USA DA - 17.02.2022 KW - Numerical Simulation KW - Radioactive Waste KW - Elastomers KW - Aging KW - Seal Behavior KW - Leakage Rate KW - Coefficient of Friction KW - Experiment PY - 2022 SP - 1 EP - 8 PB - American Society of Mechanical Engineers (ASME) CY - New York, NY, USA AN - OPUS4-57093 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Zaghdoudi, Maha A1 - Brandt, Guido A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Coefficients of Friction in Dependence on Aging State of Elastomers – Experimental Identification and Numerical Simulation of the Experiment N2 - Elastomer seals are mounted as barrier seals in lid systems of containers designed for transport and disposal of negligible heat generating radioactive waste and as auxiliary seals in spent fuel storage and transportation casks (dual purpose casks (DPC)). When the behavior of mounted seals under normal and hypothetical accident conditions of disposal and transport is to be simulated, a comprehensive knowledge of their complex mechanical properties at every state of aging is necessary. In previous works, BAM’s efforts in experimental investigations on specimen artificially aged at different temperatures and times and the implementation of the found results in finite element material models were presented. Additionally, our approaches to reproduce the aging process itself and to extrapolate the results of artificially accelerated aging to longer times were presented. Numerical simulations have shown that the behavior of the seal during mounting and one-sided pressurizing and the resulting performance values such as leakage rate strongly depend on the coefficient of friction (COF) between flange and seal. The friction coefficient, in turn, depends on the aging state of the elastomer material as several publications suggest (see below). Dynamic COF between an exemplary ethylene propylene diene rubber (EPDM) material and a stainless steel ball were determined by using a self-designed linear oscillation tribometer. Unaged and artificially aged EPDM specimen stored for 30 days and 100 days at a temperature of 150 °C were tested. A stainless steel ball (d=10 mm) is brought in contact with the specimen’s surface und loaded by normal forces of 2.5 N, 5 N, 10 N and 20 N. During a reciprocating movement of the EPDM sheet, the horizontal force/friction force is continuously measured, and the COF can be derived. It is well known that friction is a complex phenomenon especially in soft materials. It cannot be excluded that the measured friction force is influenced by additional force components, resulting from the ball’s grooving through the elastomer’s surface. This force depends on the penetration depth of the ball and on the resistance of the elastomer in its different states of aging. The latter results from microstructural changes i.e., chain scission and additional crosslinking that occur during aging which in turn influence the softening or hardening of the material. A finite element (FE) ABAQUS® model was developed to reproduce the measurement process. It should help to better understand the physical mechanisms and to quantify the percentage of measured forces resulting from real friction on the one hand and forces resulting from unintended side effects that could falsify the result on the other hand. The behavior of the elastomer in its different states of aging is reproduced by a FE material model already presented in previous works of BAM. T2 - ASME 2022 Pressure Vessels & Piping Conference (PVP2022) CY - Las Vegas, NV, USA DA - 17.07.2022 KW - Radioactive Waste KW - Elastomers KW - Aging KW - Experiment KW - Seal Behavior KW - Numerical Simulation KW - Leakage Rate KW - Coefficient of Friction PY - 2022 AN - OPUS4-57095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -