TY - CONF A1 - Musolff, André A1 - Quercetti, Thomas A1 - Müller, Karsten A1 - Droste, Bernhard A1 - Gründer, Klaus-Peter T1 - Experimental testing of impact limiters for RAM packages under drop test conditions N2 - In context with new cask designs and their approval procedure, the experimental testing of impact limiters under drop test conditions becomes more and more important in order to assess the damage mechanics behaviour and safety margins for validation reasons. In recent years, various designs of impact limiters have been tested by the Federal Institute for Materials Research and Testing within specific component testing and particularly with regard to type B package design approval procedures. The paper focuses on the experimental realisation of impact limiter tests and presents implemented measurement techniques to determine the amount of deformation and to explain the impact behaviour by means of photogrammetric metrology and three-dimensional fringe projection method, high speed motion analysis and adjusted deceleration measurements. T2 - PATRAM 2013 - 17th International symposium on the packaging and transportation of radioactive materials CY - San Francisco, CA, USA DA - 18.08.2013 KW - Drop test KW - Impact limiters KW - RAM packages KW - Measurement methods PY - 2013 SP - 1 EP - 9 PB - Omnipress AN - OPUS4-31040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Musolff, André A1 - Quercetti, Thomas A1 - Droste, Bernhard A1 - Müller, Karsten A1 - Gründer, Klaus-Peter T1 - Experimental investigation of RAM packages impact limiters - 14256 N2 - In context with new cask designs and their approval procedure the experimental testing of impact limiters under drop test conditions becomes more and more important in order to assess the damage mechanics behavior and safety margins for validation reasons. In recent years various designs of impact limiters have been tested by the Federal Institute for Materials Research and Testing (BAM) within specific component testing and particularly with regard to type B package design approval procedures. The paper focuses on the experimental realization of impact limiter tests and presents implemented measurement techniques to determine the amount of deformation and to explain the impact behavior by means of photogrammetric metrology and 3-d fringe projection method, high-speed motion analysis and adjusted deceleration measurements. T2 - WM2014 Conference CY - Phoenix, Arizona, USA DA - 02.03.2014 KW - Drop test KW - Impact limiters KW - RAM packages KW - Measurement methods PY - 2014 SN - 978-0-9836186-3-8 SP - Paper 14256, 1 EP - 10 AN - OPUS4-31050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz ED - Carletti, E. ED - Crocker, M. ED - Pawelczyk, M. ED - Tuma, J. T1 - Dynamic measurements during drop tests on stiff foundations N2 - Measurements at the foundation, the surrounding soil and nearby buildings have been done during several drop tests of different containers on different foundations. The first measurements have been done on a big foundation where it should be guaranteed that the foundation is rigid and the container is tested properly. It was controlled that the foundation does not absorb more than 2 percent of the energy of the container. Most of the drop energy is lost in shock absorbers. Later on, a smaller drop test facility has been built on the ground but inside an existing building. It had to be controlled by prediction and measurements that the drop test will not damage the building. Tests from different heights on soft, medium, and stiff targets have been done to find out rules which allow to identify acceptable and unacceptable drop tests. Later on, the biggest drop test facility has been built for masses up to 200 t. It was necessary for the design of the foundation to estimate the forces which occur during the drop tests. On the other hand, the acceptable tests should be selected and controlled by measurements where the impact duration is important. Different sensors, accelerometers, accelerometers with mechanical filters, geophones (velocity transducers), strain gauges, and pressure cells have been applied for these tasks. The signals have been transformed to displacements which proved to be best suited for the interpretation of the impact mechanism. Modell calculations have been used to check and understand the dynamic measurements. The simplest law is the conservation of the momentum which is a good approximation if the impact is short. If the soil under the foundation has an influence on the deceleration of the container, the maximum foundation velocity is lower than the simple estimation. The amplitudes of the foundation could also be estimated from the ground vibrations and their amplitude-distance law. T2 - 27th International Congress on Sound and Vibration (ICSV27) CY - Online meeting DA - 11.07.2021 KW - Drop test KW - Vibration measurement KW - Container loading KW - Foundation load PY - 2021 SN - 978-83-7880-799-5 SN - 2329-3675 SP - 1 EP - 8 PB - Silesian University Press CY - Gliwice, Poland AN - OPUS4-53255 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nehrig, Marko A1 - Scheidemann, Robert A1 - Wille, Frank A1 - Ballheimer, Viktor T1 - Investigation of the internal impact during a 9 m drop test of an accident-safe waste package N2 - The safety assessment of packages for the transport of radioactive material follows the IAEA regulations and guidance. The specified regulatory tests cover severe accidents and demonstrate the package containment system integrity. Special attention must be drawn to the behaviour of the content which could move inside the package due to unpreventable gaps caused by the loading procedure and the structure of the content. A possible internal impact of the content which occurs during the drop tests onto the lid system is investigated. The IAEA regulations SSR-6 and the Guidance SSG-26, revised recently, consider input from Germany and France related to the significance of internal gaps. In the context of a waste package design assessment, a model was equipped with a representative content to conduct a drop test with an internal impact. The weight and kinetic impact of this content covered all possible real contents. The objective of the test was to maximize the load onto the lid system and to prove the mechanical integrity by complying with the required leak tightness. The test was conducted conservatively at a package temperature lower than -40 °C at the BAM Test Site Technical Safety. This paper gives an overview of efforts to address internal gaps and their consequences, and the BAM efforts with the implementation of this topic into IAEA regulations and guidance material. The paper then focuses on the conduction of a drop test and investigation of internal component impact. T2 - ASME 2021 Pressure Vessels & Piping Conference (PVP2021) CY - Online meeting DA - 13.07.2021 KW - Internal gaps KW - Drop test KW - IAEA PY - 2021 SN - 978-0-7918-8535-2 DO - https://doi.org/10.1115/PVP2021-60996 SP - 1 EP - 6 PB - American Society of Mechanical Engineers (ASME) CY - New York, NY, USA AN - OPUS4-54742 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Völzke, Holger A1 - Zencker, Uwe A1 - Herz, A. A1 - Kreienmeyer, M. T1 - Design of a Drop Test Target with Reproducible Properties for Konrad Prototype Testing N2 - Beginning in 1976 the former iron ore mine Konrad was geologically investigated concerning its suitability as a location for a German final repository for low and intermediate level waste. After a comprehensive licensing procedure it was approved and is now being prepared and equipped for the planned start of storage in 2027. At the end of the 1980s, the requirements for waste containers for storage in this repository were defined for the first time on the basis of an incident analysis of the on-site handling procedures, beginning with the unloading of the packages after the arrival at the site up to the final positioning in the underground storage galleries. A 5-meter drop onto the rock ground of the mine was identified as the covering case for high mechanical requirements (ABK II container class). In contrast to the 9-meter drop according to the IAEA Regulations for the Safe Transport of Radioactive Material, the 5-meter drop is performed onto a hard but not essentially unyielding target. The container is typically not protected by an impact limiter. The requirements for a potential test facility are described in the regulations for the Konrad repository. The mechanical strength of the target is defined as a concrete strength equivalent to the identified properties of the rock ground of the mine. Since 1991 BAM has consistently used precast reinforced concrete slabs as target for drop tests in the framework of licensing procedures as well as in research projects. While the original design fulfilled the requirement for the integrity of the concrete slab in most cases, it failed when drop tests onto an edge of a container were performed. A redesigned concrete slab developed in a research project and suggested as a reference target in 2009 has been successfully used in Konrad licensing procedures since then. The paper gives a brief overview of the historical development and it describes BAM’s efforts and approaches to continuously guarantee a concrete slab of defined quality and to provide a test setup for valid drop tests from the applicants and the authorities view. T2 - PATRAM 2022, 20th International Symposium on the Packaging and Transportation of Radioactive Materials CY - Juan-les-Pins, France DA - 11.06.2023 KW - Target KW - Drop test KW - Final repository Konrad PY - 2023 SP - 1 EP - 11 AN - OPUS4-58563 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheidemann, Robert A1 - Qiao, Linan A1 - Müller, Karsten T1 - Comparison of experimental results and numerical simulations of penetration tests with damping concrete N2 - The shock absorbing material damping concrete is for the foundation in dry interim storage facilities for radioactive waste in Germany. In case of a potential cask drop damping concrete minimizes the mechanical loads to the cask. In course of safety analyzes this accident scenario is considered by numerical simulations using the finite element method. To get reliable results of numerical simulations a suitable material model is needed to take the characteristics of damping concrete into account. Due to the lack of sufficient material knowledge a research project was started to characterize the material’s behavior under different load conditions. This paper presents the test program to analyze the material behavior of damping concrete which is characterized by large volume change and strain rate hardening dependence. The determined Parameters were used to adapt an existing material model of the FE-code ABAQUS®. This model has to handle the mechanical damage behavior of damping concrete which occurs under compression and shear loads during a potential cask drop. To verify the material model numerical simulations are compared with dynamic penetration tests, which were conducted with specimens assembled similar to the real application of the damping concrete footings. The transferability of the material model to a real accident scenario was verified by a drop test with a full-scale cask on a damping concrete footing. T2 - ASME 2017 Pressure Vessels & Piping Conference (PVP2017) CY - Waikoloa, Hawaii, USA DA - 16.07.2017 KW - Drop test KW - Damping concrete KW - Cask KW - Material model PY - 2017 SN - 978-0-7918-5802-8 VL - 7 SP - Article UNSP V007T07A034, 1 EP - 6 PB - The American Society of Mechanical Engineers CY - New York AN - OPUS4-44042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias ED - Werner, Klaus-Dieter T1 - Temperature characteristics of a piezoresistive accelerometer for high impact shock application N2 - This study presents the characterization of a piezoresistive accelerometer damped with silicon oil for the application in drop tests carried out at BAM. Experiments were performed with the Hopkinson Bar method in close correlation to the real-world application conditions. The results point out certain limitations regarding the temperature influence and the frequency response. Additional experiments were performed with a gas damped type of piezoresistive accelerometer, which has superior specifications, particularly for low temperatures. The results allow for a comparison. T2 - Sensoren und Messsysteme CY - Nürnberg, Germany DA - 26.06.2018 KW - Piezoresistive accelerometer KW - High impact shock application KW - Drop test KW - Temperature characteristics KW - Hopkinson bar PY - 2018 SN - 978-3-8007-4683-5 SN - 0932-6022 SP - 465 EP - 467 PB - VDE Verlag GmbH CY - Berlin AN - OPUS4-45323 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Werner, Klaus-Dieter A1 - Johann, Sergej A1 - Daum, Werner ED - Cosmi, F. T1 - Characterization of the temperature behavior of a piezoresistive accelerometer N2 - Piezoresistive accelerometers use a strain-sensing element, generally made of semiconductor material, e.g., silicon to convert the mechanical motion into an electrical signal. This element is usually designed in form of a cantilever beam loaded with a mass. Acceleration causes bending of the beam, which produces a change of electrical resistance proportional to the applied acceleration. Main advantages of piezoresistive accelerometers in comparison to other types, e.g., piezoelectric and capacitive, is their robust and highly dynamic behavior, which qualifies them for application in high impact shock applications. Mechanical damping is typically implemented with silicon oil in a way that the output signal is undistorted over a wide frequency range. These characteristics principally qualify them for the application in drop tests carried out at BAM, for which they are calibrated over the frequency range from 1 to 4 kHz. However, using silicon oil for damping, has the drawback of temperature dependent change of its viscosity, leading to temperature dependent deviation of the accelerometer’s sensitivity. This study presents experimental results of the temperature behavior of a piezoresistive accelerometer with a dynamic range up to ±5000 g. This type of accelerometer is applied for drop tests which are partially performed at temperatures of -40 or +100 °C. T2 - 34th Danubia-Adria Symposium on Advances in Experimental Mechanics CY - Trieste, Italy DA - 19.09.2017 KW - Accelerometer KW - Temperature behavior KW - Drop test PY - 2017 UR - https://www.openstarts.units.it/handle/10077/14921 SN - 978-88-8303-863-1 SP - 93 EP - 95 CY - Trieste AN - OPUS4-42109 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Völzke, Holger T1 - Influence of impact angle and real target properties on drop test results of cubic containers N2 - Drop test scenarios with cubic containers without impact limiters at interim storage sites or in a final repository have been investigated by numerical simulations. An ideally flat drop is impossible to conduct as a free fall of a container even under laboratory conditions. Dynamic stresses and strains inside the container structure are sensitive to the impact angle. Even very small impact angles cause remarkable changes in the experimental or numerical results when a flat bottom or wall of a container hits a flat target. For drop tests with transport packages the International Atomic Energy Agency (IAEA) regulations define an essentially unyielding target. In contrast, potential accident scenarios for storage containers are derived from site-specific safety analyses or acceptance criteria in Germany. Each interim storage site or repository has a yielding or so-called real target with individual structural and material properties. The real target acts as a kind of impact limiter. A more conservative container design is required if the impact limiting effect of the target is not considered. T2 - ASME 2017 Pressure Vessels and Piping Conference CY - Waikoloa, Hawaii, USA DA - 16.07.2017 KW - Finite element method KW - Simulation KW - Drop test KW - Impact angle KW - Real target KW - Yielding target PY - 2017 SN - 978-0-7918-5802-8 DO - https://doi.org/10.1115/PVP2017-65731 VL - 7 SP - Article UNSP V007T07A039, 1 EP - 9 AN - OPUS4-43631 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Völzke, Holger A1 - Nieslony, Gregor T1 - Consequences of an imperfectly mounted reinforcement cage in a generical cylindrical concrete container during mechanical specimen tests N2 - By highest court decision in 2007 the issued license for the Konrad repository (a former iron ore mine) for low and intermediate level radioactive waste was finally confirmed. Since then, the site is improved, prepared and equipped for the currently planned start of waste package emplacement by 2029. The Bundesanstalt fuer Materialforschung und -pruefung (BAM, Federal Institute for Materials Research and Testing) is regularly contracted by the Bundesgesellschaft für Endlagerung (BGE, Federal Company for Radioactive Waste Disposal) as the responsible authority for waste product control, waste container design testing, and waste package acceptance. In this context BAM is mainly responsible for design testing of various container types including the evaluation quality assurance measures for container manufacturing. In the written Konrad disposal requirements all acceptance criteria for potential final disposal containers are defined. In addition to general requirements concerning container design, materials, dimensions and others, specific mechanical load scenarios the casks have to withstand are derived from an analysis of the on-site handling and emplacement procedures. Drop tests from different heights under consideration of the most damaging drop orientation and a stacking test are two examples for safety demonstrations that have to be performed during the container design testing procedure to qualify the respective container type. The containers, whether cubic or cylindrical containers, can be made from different materials like ductile cast iron, reinforced concrete or as welded construction from steel plates and profiles. In case of concrete containers the reinforcement has the function to absorb tensile forces the concrete is not able to withstand by its own. Because of manufacturing imperfections of cylindrical concrete waste containers manufactured already decades ago, the reinforcement cages are not always exactly, axisymmetrically positioned when they were poured. This inspired BAM to perform various ABAQUS finite-element (FE) simulations by using the example of a simplified cylindrical container design with generic dimensions and pure elastic material properties. As outcome the stress conditions in the container during the drop test impact under different drop positions and during the stacking test were investigated and are explained and illustrated in this contribution. Different reinforcement cage positions were calculated and compared. On the basis of the calculated tensile and compressive stress distributions suggestions are derived on how a cylindrical concrete container with an imperfectly placed reinforcement cage has to be oriented for a drop or stacking test to ensure the most damaging test scenario. T2 - ASME 2024 Pressure Vessels & Piping Conference CY - Bellevue, Washington, USA DA - 28.07.2024 KW - Container design testing procedure KW - Reinforced concrete containers KW - Drop test KW - Stacking test KW - Imperfectly mounted reinforcement cage KW - Finite-element-analysis PY - 2024 SN - 978-0-7918-8851-3 DO - https://doi.org/10.1115/PVP2024-123797 VL - 5 SP - 1 EP - 8 PB - ASME CY - New York City, USA AN - OPUS4-62558 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -