TY - CONF A1 - Scheidemann, Robert A1 - Weber, Mike A1 - Völzke, Holger A1 - Kasparek, Eva Maria ED - Gomes, J.F.Silva ED - Meguid, S.A. T1 - Temperature dependendency of dynamically loaded polyurethane foam N2 - Polyurethane foam used as impact limiter material undergoes high plastic deformations, whereat the resulting stress-strain relations strongly depend on loading speed and temperature. This paper discusses the efforts necessary to develop a reliable numerical foam simulation model focussing on generation and implementation of temperature- dependent yield curves T2 - 6th International Conference on Mechanics and Materials in Design CY - Ponta Delgada, Azores, Portugal DA - 26.07.2015 KW - Impact limiter KW - Polyurethane foam KW - Finite element model KW - Strain rate KW - Temperature dependency PY - 2015 SN - 978-989-98832-3-9 SP - 1043 EP - 1046 PB - INEGI-FEUP AN - OPUS4-38889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisenacher, Germar A1 - Scheidemann, Robert A1 - Neumann, Martin A1 - Wille, Frank A1 - Droste, Bernhard T1 - Crushing characteristics of spruce wood used in impact limiters of type B packages T2 - PATRAM 2013 - 17th International symposium on the packaging and transportation of radioactive materials CY - San Francisco, CA, USA DA - 2013-08-18 KW - Spruce wood KW - Crush test KW - Impact limiter PY - 2013 SP - 1 EP - 10(?) PB - Omnipress AN - OPUS4-30219 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisenacher, Germar A1 - Scheidemann, Robert A1 - Neumann, Martin A1 - Wille, Frank A1 - Droste, Bernhard T1 - Approach for a finite element material model for wood for application in mechanical safety cases of transport packages N2 - BAM Federal Institute for Materials Research and Testing is the competent authority for mechanical safety assessment of transport packages for radioactive material in Germany. The further development of state-of-the-art technology concerning assessment methods is essential for a qualified work of involved designers and authority experts. The paper gives an example of current development done to improve understanding and modeling capabilities of wood filled impact limiter. In order to reduce the loads applied to the package containment, which result from regulatory drop tests, most packages are protected by energy dissipating impact limiter. Wood, encapsulated by steel sheets, is one of the materials typically used for energy dissipation in these impact limiter. Very often, mechanical safety cases regarding the 9 m drop test are performed computationally, where it is essential to use reliable and verified computational methods and models. In this context, the paper presents an approach for a finite element material model for wood. Thereby, the mechanical behavior of wood under compression loading is the focus of the development work. Additionally, material orientation as well as strain rate, temperature and lateral constraint may vary. A large number of experiments, particularly compression tests, was designed and performed to establish an adequate experimental database for modeling verification. The experimental results enabled the derivation of necessary requirements: The material model has to take into account strain rate and temperature dependencies as well as the anisotropic characteristics of the material, a proper yield criterion, flow rule and hardening law. Such a material model is currently not available in established commercial dynamic finite element codes. Thus it is necessary to create a user-defined material model considering the mentioned requirements. A first step was done by determining a yield surface as well as detecting flow and hardening mechanisms from experimental force-deflection curves. In a next step the LS-DYNA material model MAT_75 was altered according to conclusions of former BAM development work, regarding the modeling of post-peak softening as a function of lateral constraint. Future research will contain the further development, implementation and verification of a material model for wood. T2 - 52nd INMM Annual meeting CY - Palm Desert, CA, USA DA - 17.07.2011 KW - Impact limiter KW - Material model wood KW - Transport package PY - 2011 SP - 1 EP - 8 AN - OPUS4-24236 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -