TY - CONF A1 - Qiao, Linan A1 - Zencker, Uwe A1 - Völzke, Holger A1 - Wille, Frank A1 - Musolff, André ED - Topping, B.H.V. T1 - Validation of numerical simulation models for transport and storage casks using drop test results N2 - The safety assessment of new designs for transport and storage casks for radioactive materials is a challenging task accomplished using different methods such as prototype tests, model tests, calculations and analogy reflections. At BAM (Federal Institute for Materials Research and Testing), the test procedures for the mechanical IAEA (International Atomic Energy Agency) test conditions often start with preliminary finite element (FE) calculations mostly with a small-scale cask model for verification of the proposed test cask instrumentation and test plan. On that basis the extensive test cask instrumentation is applied and checked. After that, a series of drop tests consisting of different test sequences is performed. Following the drop tests, numerical post-analyses are carried out. These analyses offer the possibility of a detailed calculation and assessment of stresses and strains in the entire test cask construction. The calculation results have to be carefully compared with the measurement data over the impact history to find out all relevant parameters for a realistic simulation of the impact scenario. The desired ideal boundary test conditions often cannot be met exactly during the drop tests. Therefore, the numerical post-analyses are carried out by using the real boundary conditions of the drop tests. The objective is to find a validated model, where the results of the numerical simulations satisfactorily meet the experimental results. Under test conditions according to the IAEA transport regulations, casks are usually equipped with impact limiters and dropped onto a so-called unyielding target. In general, it is difficult to verify a complex FE model by using results from only one drop test because of the complex impact process and the complex structure of such packages. After each drop test, numerical post-analyses should be carried out. Only if all drop tests were simulated successfully by using the same FE model under different test conditions, it is possible to obtain a validated numerical model for further investigations. In this case the results of the numerical simulations meet satisfactorily the experimental results. In this paper a study is presented, where the influence of different components on the cask loading is investigated systematically. T2 - 11th International conference on computational structures technology CY - Dubrovnik, Croatia DA - 04.09.2012 KW - Impact KW - Simulation KW - Cask KW - Dop test KW - Finite element model KW - Validation KW - Dynamics KW - Transport and storage cask PY - 2012 DO - https://doi.org/10.4203/ccp.99.273 SN - 1759-3433 IS - Paper 273 SP - 1 EP - 12 PB - Civil Comp Press AN - OPUS4-26537 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Protz, Christian A1 - Völzke, Holger A1 - Ellouz, Manel A1 - Kasparek, Eva Maria A1 - Zencker, Uwe A1 - Grünewald, Heike A1 - Gründer, Klaus-Peter T1 - ConDrop - Development of numerical simulation approaches for drop test analyses of steel sheet containers N2 - According to disposal requirements, containers for radioactive waste have to withstand drop tests at defined conditions corresponding to the considered package category. Alternatively to prototype drop tests, numerical methods can be applied, if they are suitable and sufficiently verified. In this context BAM (Federal Institute for Materials Research and Testing) started the research project ConDrop to develop a reliable Finite Element (FE) model describing the mechanical behavior of a box shaped steel container during a drop test and to determine unfavorable scenarios within future safety assessment procedures of comparable steel sheet containers. In a first step, a FE model of a representative steel sheet container was developed. Flat bottom-side drop tests with the unloaded container from different heights onto an IAEA target were simulated. In order to verify the numerical calculations, two drop tests with an unloaded KONRAD Type V steel sheet container were carried out at the BAM drop test facility. Both drop tests (flat drop from heights 0.4 m and 5 m onto the unyielding IAEA target) had been documented by various extensive measurements: strain and deceleration measurement by means of strain gauges and accelerometers, high-speed video as well as optical 3D-measurements using the method of projected fringes in combination with close range photogrammetry. The measured strain and deceleration values are presented and compared with the calculated results. T2 - 53rd INMM Annual meeting CY - Orlando, FL, USA DA - 15.07.2012 KW - INMM 53rd annual meeeting PY - 2012 SP - 1 EP - 7 AN - OPUS4-26417 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 N2 - Safety assessments of Containers for Transport and storage of radioactive materials involvedrop scenarios prescribed in the regulations of the International Atomic Energy Agency - IAEA or potential accidents that might occur in a specific nuclear facility. Hereby, the design of impact limiters and foundation properties of the handling Region have a major effect on the mechanical loading of the cask and lid System. Reliable numerical simulations, which very often constitute a relevant part of such safety proofs, require systematic information About the energy absorption potential of the respectiye materials and its implementation in FEM (finite element) programs. However, when performing drop tests, BAM (BAM Bundesanstalt für Materialforschung und -prüfung, Federal Institute for Materials Research and Testing) identified significant differences between numerical and experimental results, which most likely result from numerical methods that do not sufficiently reproduce the behaviour of impact limiting structures. Particularly concerned are Container impact limiter made of wood or Polyurethane foam as well as damping concrete bricks, which are embedded in foundations of German interim storages. 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 - 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 N2 - Rigid, closed-cell polyurethane foams are frequently used as cask impact limiters in nuclear materials and hazardous waste transport due to their high energy-absorption potential. When assessing the cask integrity in accidental scenarios based on numerical simulations, a description of the foam damping properties is required for different strain rates and for a wide temperature ränge with respect to waste heat generation in conjunction with critical operating and environmental conditions. Implementation and adaption of a respective finite element material model strongly relies on an appropriate experimental data base. Even though extensive impact experiments were conducted e.g. in Sandia National Laboratories, Savannah River National Laboratory and by Rolls Royce plc, not all relevant factors were taken into account. Hence, BAM who is in Charge of the mechanical evaluation of such packages within the approval procedure in Germany, incorporated systematic test series into a comprehensive research project aimed to develop numerical methods for a couple of damping materials. In a first step, displacement driven compression tests have beenperformed on confined, cubic specimens at five loading rates ranging from 0.02 mm/s to 3 m/s attemperatures between +90°C and -40°C. Materials include two differentPolyurethane foam types called FR3718 and FR3730 having densities of 280 kg/m3 and 488 kg/m3 from the product line-up of General Plastics Manufacturing Company. Their data was used to adapt an advanced plasticity model allowing for reliably simulating cellular materials under multi-axial compression States, Therefore, an automated parameter identification procedure had been established by combining an artificial neural network with local optimization techniques. Currently, the selected numerical material input values are validated and optimized by means of more complex loading configurations with the prospect of establishing methods applicable to impact limiters under severe accidental conditions. The reference data base is provided by experiments, where weights between 212 kg and 1200 kg have been dropped from heights between 1.25 m and 7 m on confined 10 cm cubic foam specimens. By presenting the deviations between experimental values and the corresponding Output of finite element simulations, the Potentials and restrictions of the resulting models are highlighted. T2 - WM2012 - Waste management conference CY - Phoenix, AZ, USA DA - 26.02.2012 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 - GEN A1 - Ammerman, D. J. A1 - Bignell, J. L. A1 - Bjorkman, G. S. A1 - Breach, M. R. A1 - Broz, V. A. A1 - Jordan, J. A1 - Kuehner, S. A1 - Molitoris, D. P. A1 - Reinhardt, W. A1 - Rigato, A. B. A1 - Rosvall, E. S. A1 - Sakalaukus Jr., P. J. A1 - Shih, P. Y.-K. A1 - Siromani, D. A1 - Snow, S. D. A1 - Tso, C.-F. A1 - Yaksh, M. C. A1 - Zencker, Uwe A1 - Zhang, X. T1 - Guidance document - Use of explicit finite element analysis for the evaluation of radioactive material transport packages and storge casks in energy-limited impact events N2 - The purpose of this document is to provide guidance for developing quality finite element models to ensure, with reasonable certainty, that the model produces accurate results for comparison with the strain-based or stress-based acceptance criteria of Section III, Division 3 of the ASME Boiler and Pressure Vessel Code, but could be applicable to other Sections of the Code or other codes. Models developed following the guidance provided in this document meet the definition of a "Quality Model," as described in Paragraph EE 1240 of the Nonmandatory Appendix EE (Strain-Based Acceptance Criteria Definitions and Background Information). It cannot be emphasized enough, however, that the guidance supplied here does not constitute requirements. Rather, the intent of the guidance is to give practical direction to analysts (i.e., this is not a set of regulatory requirements). This guidance document is an "evolving" document. It will undergo revision as computing capability and FEA techniques progress, and as example problems are developed. KW - Computational modeling KW - Explicit dynamics PY - 2025 SN - 978-0-7918-7749-4 VL - NTB-6 SP - 1 EP - 153 PB - Americal Society of Mechanical Engineers (ASME) CY - New York, NY ET - 2025 AN - OPUS4-65759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -