TY - JOUR A1 - Dreßler, Martin A1 - Dombrowski, Felix A1 - Simon, Ulla A1 - Börnstein, Julian A1 - Hodoroaba, Vasile-Dan A1 - Feigl, Michael A1 - Grunow, Sabrina A1 - Gildenhaar, Renate A1 - Neumann, Martin T1 - Influence of gelatine coatings on compressive strength of porous hydroxyapatite ceramics N2 - Porous ceramics prepared by the foam replication technique have a high porosity and low mechanical stability. It has been reported that coating such porous ceramics with gelatin allows for an improved compressive strength. Little details regarding the influence of important gelatin parameters such as concentration, temperature and drying conditions as well as bloom number which is a measure of the gel rigidity, on this toughening effect are available. This paper investigates the influence of these parameters on compressive strength of gelatin coated porous hydroxyapatite ceramics. It was found that concentration in the gelatin sols has a marked impact whereas sol temperature, bloom number and differing conditions during subsequent drying have only little influence on the compressive strength of the coated ceramics. KW - Films KW - Composites KW - Strength KW - Apatite KW - Biomedical application PY - 2011 DO - https://doi.org/10.1016/j.jeurceramsoc.2010.11.004 SN - 0955-2219 SN - 1873-619X VL - 31 IS - 4 SP - 523 EP - 529 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-23216 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neumann, Martin A1 - Gleim, Tobias A1 - Gradt, Thomas T1 - Friction coefficients for wood-wood and wood-steel high pressure contact under temperatures between -40 °C and 90 °C N2 - Wood is widely used in impact limiters of Transport casks for radioactive material. Encapsulated by an outer and inner Steel structure, spruce wood is offen applied in layers of altemating direction. The friction at the interfaces between these layers is of crucial importance for the impact and energy absorption e.g., at an accidental impact of a cask against a hard component. In order to get detailed Information for corresponding numerical calculations, in this study the friction coefficient for the combinations wood-wood and wood-steel was measured in the temperature ränge between -40 °C and 90 °C according to the relevant stress conditions for such casks. Results show decreasing friction with increasing temperature, ranging from 0.43 at -40 °C to 0.22 for 90 °C for wood-steel combinations and from 0.3 at -40 °C to 0.24 at 90 °C to for a wood-wood combination. KW - Wood KW - Friction KW - Transport cask KW - Radioactive material PY - 2023 DO - https://doi.org/10.24053/TuS-2023-0007 SN - 0724-3472 VL - 70 IS - 2 SP - 5 EP - 12 PB - expert verlag AN - OPUS4-57787 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eisenacher, Germar A1 - Kuschke, Christian A1 - Schubert, Sven A1 - Neumann, Martin A1 - Sterthaus, Jens A1 - Nitz, Thilo A1 - Wille, Frank T1 - Moisture content of wood: influence on mechanical behaviour of wood filled impact limiters and importance for quality surveillance during manufacturing N2 - The moisture content of wood is known to have a significant influence on the wood's mechanical properties. Using wood as an energy absorber in impact limiters of packages for the transport of radioactive material, it is of particular importance to ensure the moisture content and thus relevant mechanical properties to be in specified limits. The paper surveys the influence of wood moisture content on the mechanical properties of wood. Different measuring methods are discussed with respect to in situ applicability, accuracy and effort. The results of an experimental analysis of the accuracy of hand held moisture metres using the electrical resistance method are discussed. Conclusions are drawn regarding the measurement of moisture content of wood upon delivery as well as of complete impact limiter assemblies. Requirements for quality surveillance during manufacturing of wood filled impact limiters are derived and it is exemplified how to meet them. Construction, manufacturing and inspection of impact limiter encapsulation with regard to leak tightness are addressed. KW - Electrical resistance method KW - Impact limiter KW - Moisture content KW - Moisture metre KW - Wood PY - 2012 DO - https://doi.org/10.1179/1746510913Y.0000000023 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 23 IS - 3-4 SP - 179 EP - 185 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-29243 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eisenacher, Germar A1 - Scheidemann, Robert A1 - Neumann, Martin A1 - Droste, Bernhard A1 - Völzke, Holger T1 - Dynamic crushing characteristics of spruce wood under large deformations N2 - An extensive series of large deformation crushing tests with spruce wood specimens was conducted. Material orientation, lateral constraint and loading rate were varied. Regarding material orientation, a reduction in the softening effect and the general force level was observed with a higher fiber-load angle. A comparison with characteristics gained by application of Hankinson's formula showed discrepancies in compression strength and the beginning of the hardening effect. Lateral constraint of the specimens caused a multiaxial stress state in the specimens, which was quantified with the applied measuring method. Further, a higher force level compared to specimens without lateral constraint and significant hardening effect at large deformations resulted. Thus, the influence of a multiaxial stress state on the force level could be determined. An increase in the loading rate led to higher force levels at any displacement value and material orientation. KW - Crushing test KW - Dynamic crushing characteristics KW - Spruce wood KW - Lateral constraint KW - Multiaxial stress state KW - Hankinson's formula PY - 2013 DO - https://doi.org/10.1007/s00226-012-0508-5 SN - 0043-7719 SN - 1432-5225 VL - 47 IS - 2 SP - 369 EP - 380 PB - Springer CY - Berlin AN - OPUS4-27743 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 - JOUR A1 - Qiao, Linan A1 - Neumann, Martin A1 - Komann, Steffen A1 - Ballheimer, Viktor T1 - Dynamic and quasi-static FE calculation of impact from 9 metre drop of spent fuel transport cask N2 - The drop from 9 m height onto a rigid target is one of the required proofs of safety for packages of radioactive materials. Direct dynamic finite element method (FEM) calculations and combined two step analytical quasi-static finite element (FE) calculations are both applied for the simulation of a 9 m drop test. This paper gives a comparative example of both approaches for the 9 m side drop simulation of the spent fuel transport cask with wood filled impact limiter. The model for dynamic FEM consists of cask body and impact limiter. Detailed material properties and geometry descriptions from each component of the impact limiter are required. The results (stress fields in the cask body) are obtained directly from the calculation. The combined method provides as intermediate results the force-deformation characteristic of impact limiter. The maximum impact limiter force determined by the law of energy conservation during the drop is then - in a second step - applied on the cask body in a quasi-static FE model in order to calculate the stresses. In this paper, the rigid body deceleration and the maximum stress in the middle of the cask body are used for the comparison between the dynamic FEM and the combined method. Similar maximum rigid body deceleration-time curves were obtained by both methods for the horizontal 9 m free fall. Concerning the stress in the cask body the dynamic FEM results oscillate about values calculated by the combined quasi-static approach. If the combined quasi-static approach is used in the safety assessment of a cask, a suitable factor has to be applied on its results to take into account the additional dynamic effects. KW - Drop test KW - Spent fuel transport cask KW - Finite element calculation KW - Dynamic simulation KW - Impact limiter KW - Wood PY - 2009 DO - https://doi.org/10.1179/174650909X12553336148026 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 20 IS - 4 SP - 174 EP - 178 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-20819 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neumann, Martin A1 - Herter, Jürgen A1 - Droste, Bernhard A1 - Hartwig, S. T1 - Compressive behaviour of axially loaded spruce wood under large deformations at different strain rates N2 - Impact limiting components of packages for the transport of radioactivematerials are often designed as wood filled steel constructions. Wood absorbs major part of the impact energy in order to minimise the impact load acting upon the containment. Dynamic impact experiments with wood filled impact limiters showed different crushing mechanisms for axially loaded wood depending on their lateral constraint. Tests on spruce wood samples (Picea abies) were performed in order to clarify the influence of strain rate from static to 30 s-1 on a) compression strength, b) stress at a global strain level of 50%, and c) energy absorption capacity at 50% deformation, including statistical evaluation of the results. Results were as follows: strain rate increase led to significantly higher compression strength, stress and strain energy at a strain level of 50%. Lateral strain restriction had no effect on compression strength; it had a significant effect on stress and strain energy at strain level of 50%. Therefore, the definition of a general yield curve for wood under large deformations is not possible, the yield curve has to be chosen taking into account lateral constraints. KW - Compression KW - Wood KW - Spruce KW - Picea abies KW - Impact PY - 2011 DO - https://doi.org/10.1007/s00107-010-0442-x SN - 0018-3768 VL - 69 IS - 3 SP - 345 EP - 357 PB - Springer CY - Berlin ; Heidelberg AN - OPUS4-22980 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - König, S. A1 - Diersch, R. A1 - Lührmann, A. A1 - Müller, Karsten A1 - Neumann, Martin A1 - Quercetti, Thomas A1 - Droste, Bernhard T1 - Full-Scale Drop Testing of the CONSTOR®, V/TC Package Program, and Preliminary Results KW - Drop test KW - Package KW - Spent fuel cask KW - Transport PY - 2005 SN - 0893-6188 VL - 33 IS - 3 SP - 4 EP - 10 PB - Institute of Nuclear Materials Management CY - Northbrook, Ill. AN - OPUS4-12269 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neumann, Martin A1 - Wille, Frank A1 - Ballheimer, Viktor T1 - Approximation of package deceleration and shock absorber deformation under 9 m drop test conditions using simplified numerical tool ImpactCalc KW - Impact limiter KW - Calculation KW - Maximum deceleration KW - Maximum deformation PY - 2008 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 19 IS - 1 SP - 35 EP - 40 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-17499 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neumann, Martin A1 - Wille, Frank A1 - Droste, Bernhard T1 - Scale model impact limiter in type assessment of radioactive material transport packages KW - Impact limiter KW - Shock absorber KW - Scaling KW - Radioactive KW - Material KW - Transport KW - Cask PY - 2008 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 19 IS - 1 SP - 53 EP - 57 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-17498 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -