TY - JOUR A1 - Qiao, Linan A1 - Nagelschmidt, Sven A1 - Herbrich, Uwe T1 - Application of a Modified Arrhenius Equation to Describe the Time-Temperature Equivalence in Relaxation Analysis of Metal Seals N2 - For the application of the time-temperature superposition principle a suitable relation is needed to describe the time-temperature shift factor α. Therefore, the Arrhenius equation is widely used due to its simple form and often leads to suitable results. Where, the Arrhenius equation presents a linear relation for the temperature-dependent shift factor in logarithmic scale ln(α) with the absolute inverse temperature (1/ϑ). However, in cases with a large temperature range which eventually include more complex reaction processes, the functional relation between ln(α) and (1/ϑ) is nonlinear in the ‘Arrhenius plot’. In those cases, the monotone change of the nonlinear range in the ‘Arrhenius plot’ can be interpreted as a transient range between two approximately linear or constant regions. An extended application of the modified Arrhenius equation from Nakamura (1989) is presented in this study for this transient range. The introduced method was applied to describe the time-temperature equivalence in the relaxation analysis of restoring seal force of metal seals, which are used in lid-systems of transport and interim storage casks for radioactive materials. But, the method is widely valid and can be used for different objectives which are characterized by thermorheologically simple behavior with nonlinear sensitivity to inverse temperature. KW - Metal seals KW - TTS principle KW - Arrhenius equation KW - Non-linear Arrhenius behavior KW - Relaxation analysis KW - Seal force PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-446759 UR - http://www.davidpublisher.org/index.php/Home/Article/index?id=33931.html DO - https://doi.org/10.17265/1934-7359/2017.09.004 SN - 1934-7359 VL - 11 IS - 9 SP - 853 EP - 861 PB - David Publishing Company CY - USA, NY 10989, Valley Cottage AN - OPUS4-44675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan T1 - Development of a finite element model for damping concrete under severe impact loads T2 - 17th International Symposium on the Packaging and Transportation of Radioactive Materials, PATRAM 2013 CY - San Francisco, CA, USA DA - 2013-08-18 PY - 2013 AN - OPUS4-29765 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheidemann, Robert A1 - Kasparek, Eva Maria A1 - Qiao, Linan A1 - Müller, Karsten A1 - Droste, Bernhard A1 - Völzke, Holger T1 - Dynamic penetration tests on shock absorbing damping concrete T2 - WM2014 Conference CY - Phoenix, Arizona, USA DA - 2014-03-02 KW - Drop test KW - Dynamic KW - Penetration KW - Damping concrete PY - 2014 SN - 978-0-9836186-3-8 SP - Paper 14166, 1 EP - 9 AN - OPUS4-31948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan T1 - Simulation von Dämpferbeton unter Stoßbelastung mit dem Crushable-Foam-Modell und zusätzlicher Schädigung T2 - Deutsche SIMULIA Konferenz 2014 CY - Dresden, Germany DA - 2014-09-25 PY - 2014 AN - OPUS4-31557 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan T1 - Simulation of Damping Concrete under Severe Impact Loads using a Crushable Foam Model with Damage Mechanisms T2 - The Twelfth International Conference on Computational Structures Technology CY - Naples, Italy DA - 2014-09-02 PY - 2014 AN - OPUS4-31558 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Wieser, Günter A1 - Qiao, Linan A1 - Protz, Christian T1 - Modeling strategies for dynamic finite element cask analyses N2 - The safety of transport packages may be demonstrated by numerical calculation of load scenarios defined in the IAEA regulations. Possible handling accidents of casks at interim storage sites or in a final repository are typically analyzed by dynamic finite element computations. In each case the investigated load scenario must be transferred into a mathematical model. Secondly the mathematical model must be transferred into a numerical model. Reliable finite element models should be developed by assembling verified sub-models of components. The finite element mesh, material modeling, initial and boundary conditions, contact definitions, and time integration as well as the benefit of pre- and post-calculations are discussed. The paper presents lessons learnt from modeling dynamic test scenarios for finite element analyses over the years. T2 - PATRAM 2013 - 17th International symposium on the packaging and transportation of radioactive materials CY - San Francisco, CA, USA DA - 18.08.2013 KW - Structural analysis KW - Dynamic numerical simulation KW - Modeling strategies KW - Discretization KW - Material modeling KW - Boundary conditions KW - Cask load scenarios PY - 2013 SP - Session A, Paper 280, 1 EP - 10 PB - Omnipress AN - OPUS4-30158 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan T1 - Numerical Investigation of a Complex Drop Test Scenario T2 - Radioactive Materials Transport and Storage Conference 2012 CY - London, England DA - 2012-05-23 PY - 2012 AN - OPUS4-25973 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan T1 - Validation of Numerical Simulation Models for Transport and Storage Casks using Drop Test Results T2 - The Eleventh International Conference on Comutational Structures Technology CY - Dubrovnik, Croatia DA - 2012-09-04 PY - 2012 AN - OPUS4-26813 LA - deu 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 - Qiao, Linan T1 - Numerische Simulation von Fallversuchen mit behälterstoßdämpfern bei unterschiedlichen Fallwinkeln mittels ABAQUS/Explicit T2 - Deutsche SIMULIA-Konferenz 2010 CY - Heidelberg, Germany DA - 2010-09-20 PY - 2010 AN - OPUS4-21763 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan T1 - Dynamic Finite Element Analyses of a Spent Fuel Transport and Storage Cask with Impact Limiters by 9 meter Drop tests T2 - 2011 SIMULIA Customer Conference CY - Barcelona, Spain DA - 2011-05-17 PY - 2011 AN - OPUS4-23458 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 - Mechanical assessment within type B packages approval - the application of static and dynamic calculation approaches T2 - PATRAM 2010 - 16th International symposium on the packaging and transport of radioactive materials CY - London, UK DA - 2010-10-03 KW - Mechanische Bewertung KW - Radioaktives Material KW - Numerische Analyse PY - 2010 SP - 1 EP - 8(?) AN - OPUS4-23384 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Völzke, Holger T1 - Strategies for numerical modelling of metal gaskets in transport and storage casks N2 - Metal gaskets in the lid system of transport and storage casks for radioactive material have to guarantee leak-tightness and safe enclosure of the radioactive inventory under normal and accident conditions during transport, in case of accidents and for the longterm interim storage. For safety assessments by nurnerical simulation of the thermomechanical behaviour of a lid system with metal gaskets, the finite element method offers three options to use: i) special gasket elements, ii) complex three-dimensional modeHing with solid elements, and iii) a simplified axisymmetric approach. Gasket elements can be adjusted by many parameters, but they give only a global representation of the experimentally observed gasket behaviour. For calculations of the entire cask including the lid system with gaskets, nonetheless this approach is recommended. To investigate the hardly measurable impact behaviour in detail or to extrapolate the long-term behaviour, a local modeHing of all parts of a gasket and their interactions with effects like elastic-plastic deformation, creep, relaxation, and friction is necessary. The three-dimensional model can describe the change of contact area between outer jacket of the gasket and flange dependent on the load conditions, what overcomes an essential limitation of special gasket elements. To simplify the problern of investigating the underlying physical effects, an axisymmetric lid system can be modelled with axisymmetric finite elements. Usually an approximation is only necessary for the helical spring of a metal gasket. This paper explains basic ideas for an adequate finite element simulation of cask lid systems with metal gaskets and their thermo-mechanical behaviour under specific load scenarios. T2 - RAMTRANSPORT 2015 - International conference on the radioactive materials transport and storage CY - Oxford, UK DA - 19.05.2015 KW - Metal gasket KW - Finite element method KW - Simulation PY - 2015 SP - Paper RAM15-27, 1-9 AN - OPUS4-34938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan T1 - Crushable Foam Model with Pressure and Stress-triaxiality Dependent Damage Mechanisms for Damping Concrete T2 - International Symposium Brittle Matrix Composites BMC-11 CY - Warsaw, Poland DA - 2015-09-28 PY - 2015 AN - OPUS4-34603 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Völzke, Holger T1 - Fracture mechanical analysis of a cylindrical cast iron cask N2 - The safety evaluation of cask components made of ductile cast iron includes investigations to prevent brittle fracture. Generally, ductile cast iron is endangered by brittle fracture especially at low temperatures (down to -40°C) and in combination with existing crack-like material defects. An applicable method is the assessment of fracture resistance using fracture mechanics according to the IAEA guidelines. The approach is based on the prevention of fracture initiation. For application of these principles for drop loads, account must be taken both of dynamic stresses within the component and dynamic material behavior. Basically, the dynamic stress intensity factor of postulated pre-existing crack-like defects is compared with the dynamic fracture toughness of the material. Applicable numerical and experimental methods for the safety assessment of cask components are demonstrated for the case of an artificially pre-cracked cylindrical cast iron cask which undergoes dynamic loading conditions as result of the hard impact between the cask and a concrete target. The proposed evaluation procedure is a combination of numerical and experimental steps. Exemplarily, the calculated stress intensity factor is compared with measured fracture toughness values from single edge notched bending specimens. T2 - 19th International Symposium on the Packaging and Transportation of Radioactive Materials (PATRAM 2019) CY - New Orleans, LA, USA DA - 04.08.2019 KW - Ductile Cast Iron KW - Brittle Fracture KW - Cylindrical Cask PY - 2019 SP - Paper 1209, 1 EP - 7 AN - OPUS4-48914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan T1 - A New Time-Temperature Equivalent Formulation for the Description of Thermo-rheologically Complex Behaviour N2 - Compared with the original time-temperature superposition (TTS) principle, an extended non-linear time-temperature equivalent (TTE) principle is suggested in this work. Results shown us, all application of TTS and most of the TTE parameters, for example, the Orr-Sherby-Dorn, Manson-Succop, Larson-Müller, Manson-Haferd, Mendelson-Roberts-Manson parameters and the more general ‘single metamodel’ from Haque–Stewart are special cases of the new suggested principle. The merits of this new method are discussed. T2 - 4th International Conference on Rheology and Modeling of Materials CY - Miskolc-Lillafüred, Hungary DA - 07.10.2019 KW - Scale/shift factor and form/stretchFactor of time-temperature relation KW - Time-temperature superposition/equivalent principle KW - Thermo-rheologically simple/complex behaviour PY - 2019 AN - OPUS4-50772 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nagelschmidt, Sven A1 - Herbrich, Uwe A1 - Qiao, Linan T1 - Applicability of developed calculation models to predict long-term behavior of metal seals – Necessary scope of tests N2 - The long-term sealing behavior of metal seals, assembled in the lid system of casks for transportation and storage of radioactive materials, has been investigated. For that purpose, phenomenological models describing the time- and temperature dependent behavior have been introduced by BAM since 2016, e.g. by using the time-temperature superposition principle. Results have shown that these models describe the relaxation behavior adequately and are suitable for extrapolations. In this work, the applicability of these models is checked by analyzing the necessary scope of tests, which must be carried out to get sufficient information about the long-term behavior of metal seals based on short-term tests. T2 - Waste Management Conference CY - Phoenix, Arizona, USA DA - 03.03.2019 KW - Metal seal KW - Time-temperature superposition principle KW - Transportation and storage cask KW - Long-term interim storage PY - 2019 SP - 19311, 1 EP - 6 AN - OPUS4-48353 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan T1 - Three-dimensional finite element analysis of O-ring metal seals considering manufacture tolerances N2 - Metal seals are widely used in various industrial branches with severe working conditions (e.g. high pressure, high temperature, corrosion, or radioactive radiation). For example, O-ring metal seals are applied in the closure lid system of transport and storage casks for radioactive materials to guarantee an approved specified leak-tightness and the safe enclosure of the radioactive inventory. Within safety assessments of those casks under normal or accident conditions during transport and long-term interim storage for several decades, numerical simulations of the thermo-mechanical behavior of metal seals by using finite element (FE) analyses are suitable and effective. In general, finite element codes provide the possibility to construct a complex three-dimensional (3D) modelling of metal seals with solid elements, cf., where all components of the metal seals are modeled in detail. This modelling is complex but allows the consideration of underlying physical effects such as elastic-plastic deformation, thermal expansion, creep/relaxation, friction and possible local damage. Therefore, this approach permits the investigation and understanding of the complex behavior of metal seals in detail which can hardly be measured for all seal components. In a prior work, the complex 3D modelling approach was applied to investigate the influence of each seal component on the global seal force by considering varying material properties and different seal diameters. In the present contribution, the influence of manufacturing tolerances is discussed. At first, the results of prior work are summarized. After that, the manufacturing tolerances of the studied O-ring metal seal types are described and the corresponding FE model with all individual components is introduced. Finally, the influence of varying manufacturing tolerances of each seal component on the global seal force is analyzed and discussed. T2 - The 2019 EMI International Conference CY - Lyon, France DA - 3. July 2019 KW - Finite element method KW - Metal seals KW - Material properties KW - Manufacturing tolerances PY - 2019 AN - OPUS4-48448 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -