TY - CONF A1 - Protz, Christian A1 - Zencker, Uwe A1 - Liebich, R. T1 - Explicit finite element analyses of drop tests with thin-walles steel sheet containers for the Konrad repository N2 - Alternatively to experimental drop tests, the mechanical safety analyses of containers for final disposal of radioactive waste with negligible heat generation in the German Konrad repository may be carried out by numerical simulations within the safety assessment procedure. In the past, safety assessments for thin-walled steel sheet containers have been done exclusively by prototype tests and unfavorable drop scenarios were determined by engineering judgment. So far, reliable numerical simulations do not exist. Therefore, a research project was started to develop numerical simulation approaches for drop test analyses and to determine existing safety margins. Comparisons of experimental and numerical results confirm that the Finite Element (FE) model represents the general mechanical behavior of the steel sheet container sufficiently. Simulations have been used to determine an unfavorable drop scenario resulting in large deformation and damage. This paper presents the investigations carried out as well as the further development of the FE model in terms of damage mechanics. T2 - ASME 2015 Pressure vessels & piping conference - PVP2015 CY - Boston, Massachusetts, USA DA - 19.07.2015 KW - Explicit dynamic FEM KW - Impact KW - Drop test KW - Steel sheet container KW - Ductile damage KW - Damage mechanics PY - 2015 SN - 978-0-7918-5702-1 SP - PVP2015-45522, 1-10 AN - OPUS4-33805 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Musolff, André A1 - Quercetti, Thomas A1 - Müller, Karsten A1 - Bartholmai, Matthias T1 - Impact Analysis of RAM Packages under Kinematic Aspects N2 - BAM is the German Federal Institute for Materials Research and Testing and the competent authority for mechanical and thermal safety assessment of transport packages for spent fuel and high level waste. In context with safety assessment of RAM packages BAM performed numerous drop tests in the last decades. The tests were mostly accompanied by extensive and various measurement techniques especially by instrumented measurements with strain gages and accelerometers. The procedure of drop testing and the resulting measurement analysis are the main methods to evaluate the safety against mechanical test conditions. Measurement techniques are dedicated to answer questions in regard to the structural integrity of a RAM package, the mechanical behavior of the prototype as well as of its content under impact conditions. Test results like deceleration-time functions constitute a main basis for the validation of assumptions in the safety analysis and for the evaluation of numerical calculations. In this context the adequate selection of accelerometers and measurement systems for the performance of drop tests is important. Therefore it is not only necessary to find suitable positions for the accelerometers at the test specimens, but also to consider technical boundary conditions as e.g. temperature. T2 - PATRAM 2016 CY - Kobe, Japan DA - 18.09.2016 KW - RAM packages KW - Drop test KW - Impact KW - Radioactive PY - 2016 UR - http://www.patram2016.org/ SP - Paper 1030, 1 AN - OPUS4-38859 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 - Komann, Steffen A1 - Ballheimer, Viktor A1 - Quercetti, Thomas A1 - Scheidemann, Robert A1 - Wille, Frank T1 - Design assessment by bam of a new package design for the transport of snf from a german research reactor N2 - For disposal of the German research reactor of the Technical University Munich FRM II a new transport and storage cask design was under approval assessment by the German authorities. The Bundesanstalt für Materialforschung und -prüfung (BAM) assessed the mechanical and thermal package safety and performed drop tests. The activity release approaches and subjects of quality assurance and surveillance for manufacturing and operation of the package were assessed by BAM as well. The cask body is made of ductile cast iron and closed by two bolted lid systems with metal seals. The material of the lids is stainless steel. On each end of the cask a wood-filled impact limiter is installed to reduce impact loads to the cask under drop test conditions. In the cavity of the cask a basket for five spent fuel assemblies is arranged. For the safety case a combination of experimental testing and analytical/numerical calculations were applied. In total, four drop tests were carried out at the BAM large drop test facility. Two tests were carried out as a full IAEA drop test sequence consisting of a 9m drop test onto an unyielding target and a 1m puncture bar drop test. The other two drop test were performed as single 9m drop tests and completed by additional analyses for considering the effects of an IAEA drop test sequence. The main objectives of the drop tests were the investigation of the integrity of the package and its safety against release of radioactive material as well as the test of the fastening system of the impact limiters. Furthermore, the acceleration and strain signals measured during the tests were used for the verification of Finite-Element-Analysis (FEA) used for the safety analysis of the package design. The finite-element models incorporated in the package design safety report include the cask body, the lid system, the inventory and the impact limiters with the fastening system. In this context special attention was paid to the modeling of the encapsulated wood-filled impact limiters. Additional calculations using the verified numerical models were done by the applicant and assessed by BAM to investigate e.g. the brittle fracture of the cask body made of ductile cask iron within the package design approval procedure. This paper describes the package design assessment from the view of the competent authority BAM including the applied assessment strategy, the conducted drop tests and the additional calculations by using numerical and analytical methods. T2 - 19th International Symposium on the Packaging and Transportation of Radioactive Materials PATRAM 2019 CY - New Orleans, LA, USA DA - 04.08.2019 KW - Numerical modelling KW - Drop test KW - Assessment method KW - Ductile cast iron KW - Package design KW - Experimental testing PY - 2019 SP - Paper 1176, 1 AN - OPUS4-49054 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Quercetti, Thomas A1 - Wille, Frank A1 - Neumann, Martin A1 - Linnemann, Konrad ED - Baraldi, P. ED - Di Maio, F. ED - Zio, E. T1 - Safety Evaluation of a Package for Radioactive Waste by Full-Scale Drop Testing N2 - As part of the evaluation of a package for the safe transport of radioactive waste the regulations of the IAEA International Atomic Energy Agency shall be fulfilled. The regulations define requirements for the package and specify mechanical and thermal test conditions. Different methods are allowed for the test performance to demonstrate compliance with the regulations. Next to calculational approaches and the use of models of an appropriate scale, the performance of full-scale testing with prototype packages respectively full-scale models is applied. The use of full-scale models has several advantages within the complete safety assessment procedure for a transport package approval. Scaling and corresponding similarity questions don’t have to be considered, additional material investigations can be limited and analyses to transfer test results to the original package design are reduced in number and complexity. Additionally, experience for future serial design procedures can be built up during manufacturing and assembling of the test model. BAM operates different drop and fire test facilities south of Berlin, Germany. BAM has started to perform a drop test campaign with a full-scale model of 120 metric tons weight for a transport package approval procedure. The paper describes experience with test preparation, drop performance and additional analyses. The measurement concept is explained and test goals regarding the package safety assessment and evaluation of safety margins are introduced. T2 - 30th European Safety and Reliability Conference and 15th Probabilistic Safety Assessment and Management Conference (ESREL2020 PSAM15) CY - Online meeting DA - 01.11.2020 KW - Slap-down KW - Transport safety KW - Package KW - Drop test KW - Similarity KW - FEA KW - Radioactive waste PY - 2020 UR - https://www.rpsonline.com.sg/proceedings/esrel2020/html/3809.xml SN - 987-981-14-8593-0 SP - Paper 3809,1 EP - 8 PB - Research Publishing Services CY - Singapore AN - OPUS4-50981 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheidemann, Robert A1 - Qiao, Linan A1 - Müller, Karsten A1 - Droste, Bernhard T1 - Determination of material parameters of damping concrete under dynamic loading N2 - The safety and integrity of casks for radioactive waste in accidental scenarios is analysed by BAM Federal institute tor Materials Research and Testing. An accidental scenario in German interim storage facilities is the drop from a crane during the handling operation. To reduce the mechanical loads to the cask a shock absorbing footing with high energy absorption capability is used in these areas. In order to analyse and evaluate such impact scenarios of casks, numerical simulations are performed. For a comprehensive simulation of an accidental scenario the behaviour of the damping concrete footing has to be taken into account as well and therefor a material model is needed. Material parameters under different loading conditions are the basis for a numerical model. For that reason a government funded research project (Kasparek, 2012) was conducted to characterise damping concrete under quasi-static as well as highly dynamic impact loading conditions. The performed tests include compression tests with and without lateral constraint small-scale and midscale penetration tests with different indenters, and finally a full-scale drop test onto a damping concrete footing. T2 - RAMTRANS 2015 - 10th International conference on radioactive materials transport and storage CY - Oxford, UK DA - 19.05.2015 KW - Drop test KW - Damping concrete KW - Material characterisation PY - 2015 SP - 1 EP - 9 AN - OPUS4-33492 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Quercetti, Thomas A1 - Scheidemann, Robert A1 - Komann, Steffen A1 - Ballheimer, Viktor A1 - Wille, Frank T1 - Package testing of a dual purpose cask for SNF from German research reactors N2 - A new dual purpose cask design was developed for the safe transport and interim storage of spent fuel elements of German research reactors. In the framework of the safety assessment within the licensing procedure the Bundesanstalt für Materialforschung und –prüfung (BAM) as competent authority performed a series of drop tests according to the IAEA-Regulations [1]. The package consists of a cylindrical thick-walled ductile cast iron cask body closed by a double lid system with metallic seals. A lid and bottom sided impact limiter consisting of a wood/steel construction limit the mechanical impact loading. The full-scale test specimen was equipped with a basket and assembled with dummy-fuel elements. The package and test specimen, respectively have a total mass of approximately 24 metric tons. The mechanical test program included three 9m free drop tests, in horizontal, vertical and oblique cask orientation onto the lid system. Additionally, a 1m-puncture drop test followed the horizontal drop test to consider an IAEA-test sequence. The horizontal and vertical drop tests were performed at a temperature of minus 40°C. During the oblique drop test the upper impact limiter was heated to +80°C. The tests were conducted onto an unyielding target, fulfilling the requirements of the IAEA regulations [1]. The test specimen was considerably instrumented with strain gauges and accelerometers. Transient strains at selected locations of the inner and outer container walls, of the primary and secondary lid, as well as of the corresponding lid bolts were measured during the drop tests. Furthermore, decelerations in different locations at the cask body and the lids were measured. The complex geometrical deformation of the impact limiters due to the impact were determined by optical 3d- measurements using the projected fringe method in combination with multi-image photogrammetry. Before and after the drop tests the leakage rate of the lid system was determined by helium leakage testing. The experimental results contribute to the evaluation of the package response to mechanical tests, demonstrating safety under normal and accident conditions of transport. Especially to the verification of the dynamic finiteelement model of the package used in the package design safety report [2]. The paper describes the performance of the drop tests, selected test results focusing on the lid screws and the cask body and the deformation of the impact limiters as well as impact kinematics, respectively. T2 - IHLRWM2019 CY - Knoxville, TN, USA DA - 14.04.2019 KW - Drop test KW - Package testing KW - Dual purpose cask PY - 2019 SN - 978-0-89448-761-3 VL - 2019 SP - paper 27283, 1 EP - 7 PB - ANS AN - OPUS4-50619 LA - eng 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 - 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 - Kasparek, Eva Maria A1 - Müller, Karsten A1 - Droste, Bernhard A1 - Völzke, Holger T1 - Model-sized and full-scale dynamic penetration tests on damping concrete N2 - Mechanical loading conditions of transport and storage casks for radioactive materials in accidental scenarios are highly affected by the behavior of both: the impact limiters and the footing materials. To minimize potential damages during the handling of casks, a so called damping concrete is frequently used for the footings in interim nuclear facilities. It obtains its shock absorbing properties through admixing of polymer cells. For a comprehensive mechanical evaluation of casks, advanced material models are also needed for damping concrete. In order to characterize the mechanical properties and to develop numerical material models, penetration tests were carried out at different test facilities of BAM. The tests contain static and dynamic penetration tests on cubic specimen with an edge length of 100 mm as well as mortared specimen with a size of 240 x 240 x 50 cm³. Indenters with different geometries and diameters were used for these model-sized penetration tests. Subsequently a full-scale cylindrical cast-iron indenter with a diameter of 110 cm was dropped of 5 m height on a realistic damping concrete footing. 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 - Dynamic KW - Penetration KW - Damping concrete PY - 2013 SP - 1 EP - 10 PB - Omnipress AN - OPUS4-30233 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 - Auersch, Lutz T1 - Impacts Between Different Drop Masses and Different Targets in Different Scales N2 - The Federal Institute of Material Research and Testing has performed many impact tests from very small laboratory tests to very big “free-field” tests with heavy containers on stiff 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. Later on, a smaller drop test facility has been built on the ground 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 oc-cur during the drop tests. In addititon, the acceptable tests should be selected and controlled by measurements where the impact duration is important. Dif-ferent sensors, accelerometers, accelerometers with mechanical filters, geo-phones (velocity transducers), strain gauges, and pressure cells have been ap-plied for these tasks. Signal transformations and model 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 esti-mation. T2 - Experimental Vibration Analysis for Civil Engineering Structures (EVACES 2023) CY - Milano, Italy DA - 30.08.2023 KW - Drop test KW - Vibration measurements KW - Container loading KW - Foundation load PY - 2023 SN - 978-3-031-39116-3 DO - https://doi.org/10.1007/978-3-031-39117-0_60 SN - 2366-2557 SP - 592 EP - 602 PB - Springer Nature Switzerland CY - Cham, Schweiz AN - OPUS4-58503 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -