TY - JOUR A1 - Korzen, Manfred A1 - Haupt, P. T1 - Über eine Materialgleichung vom viskoelastisch-plastischen Typ PY - 1988 SN - 0044-2267 SN - 0946-8463 VL - 68 IS - 4 SP - T 203 EP - T 204 PB - Wiley-VCH CY - Potsdam AN - OPUS4-12081 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Korzen, Manfred A1 - Haupt, P. A1 - Tsakmakis, Ch. T1 - Über Verfestigungsmodelle der Plastizitätstheorie in funktionaler Darstellung PY - 1987 SN - 0044-2267 SN - 0946-8463 VL - 67 IS - 4 SP - T 193 EP - T 194 PB - Wiley-VCH CY - Potsdam AN - OPUS4-12082 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Korzen, Manfred A1 - Magonette, G. A1 - Buchet, Ph. T1 - Mechanical loading of columns in fire tests by means of the substructuring method PY - 1999 SN - 0044-2267 SN - 0946-8463 VL - 79 IS - S2 SP - S617 EP - S618 PB - Wiley-VCH CY - Potsdam AN - OPUS4-12018 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kamlah, M. A1 - Korzen, Manfred A1 - Tsakmakis, Ch. T1 - Uniaxial ratchetting in rate-independent plasticity laws PY - 1997 SN - 0001-5970 SN - 1619-6937 VL - 120 SP - 173 EP - 198 PB - Springer CY - Wien AN - OPUS4-12020 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Korzen, Manfred A1 - Staus, St. T1 - Isotrope nichtlineare Viskoelastizität mit Hilfe von Maßstabsfunktionen der Gedächtnisspannung PY - 1994 SN - 0044-2267 SN - 0946-8463 VL - 74 SP - 325 EP - 326 PB - Wiley-VCH CY - Potsdam AN - OPUS4-11489 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Korzen, Manfred A1 - Tsakmakis, Ch. T1 - Uniaxial ratchetting in linear viscoelasticity PY - 1997 SN - 0001-5970 SN - 1619-6937 VL - 120 SP - 173 EP - 198 PB - Springer CY - Wien AN - OPUS4-11490 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pan, Zuo-Fen A1 - Schriever, Robert A1 - Bock, Hans Michael A1 - Korzen, Manfred T1 - Comparison of the temperature distribution in isolated steel columns tested in two furnaces PY - 1997 SN - 0015-2684 SN - 1572-8099 VL - 33 SP - 316 EP - 335 PB - Kluwer Academic CY - Norwell, Mass. AN - OPUS4-11492 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hörold, Andreas A1 - Schartel, Bernhard A1 - Trappe, Volker A1 - Korzen, Manfred A1 - Naumann, Maurice T1 - Structural integrity of sandwich structures in fire: an intermediate-scale approach N2 - A test set-up in intermediate scale was conceived to investigate the structural integrity of materials under fire. The task was to develop a realistic test scenario targeting component-like behaviour. Carbon-fibre-reinforced sandwich specimens (500 X 500 X 20 mm) were used to examine failure mechanisms, times to failure and critical failure loads under compression. Fire tests were performed with fully developed fire applied to one side of the specimen by an oil burner. In a first test series, the applied load was varied, but the fully developed fire remained unchanged. In general, times to failure were short. Decreased load levels resulted in prolonged times to failure and led to a different failure mechanism. Results obtained in the test series were compared with a bench-scale study (150 X 150 X 20 mm) investigating identical material. The comparison clearly revealed the influence of size on the time to failure and the load-bearing capacity. KW - Fire testing KW - Structural integrity KW - Carbon-fibre-reinforced plastics KW - Fully developed fire KW - Composites PY - 2013 U6 - https://doi.org/10.1080/15685543.2013.816620 SN - 0927-6440 SN - 1568-5543 VL - 20 IS - 9 (Special Issue: ECCM15: Part 3) SP - 741 EP - 759 PB - VSP CY - Zeist AN - OPUS4-29647 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Huismann, Sven A1 - Korzen, Manfred A1 - Rogge, Andreas T1 - Entwicklung und Validierung eines allgemeinen Rechenverfahrens für Stahlbetonstützen aus hochfestem Beton unter Brandbeanspruchung N2 - Ausgehend von einer kritischen Analyse der Materialkennwerte für normalfesten (NFB) und hochfesten Beton (HFB) im Eurocode 2 wurden in grundlegenden Untersuchungen an der BAM exemplarisch für einen HFB die thermomechanischen Materialkennwerte bestimmt, um auf der Basis eines geeigneten Materialmodells das Verhalten von Stahlbetonstützen aus HFB unter Brandbeanspruchung zu simulieren. Die Validierung des Modells erfolgte mittels großmaßstäblicher Brandversuche an belasteten Stahlbetonstützen aus dem gleichen HFB wie in den Materialuntersuchungen. Es konnte gezeigt werden, dass die Festigkeit als charakteristischer Parameter des Materialmodells zwingend auf der Basis instationärer Versuche – und nicht aus stationären Versuchen wie bei NFB üblich – bestimmt werden muss. Mit den in vorgeschlagenen Materialbeziehungen für HFB wird das Tragverhalten der untersuchten Stützen dagegen deutlich überschätzt, was sich in den numerischen Simulationen insbesondere durch zu geringe Verformungen äußert.------------------------------------------------------------------------------------------------------ Development and Validation of an Advanced Calculation Model for High Strength Concrete Columns Subjected to Fire Loading Following a critical analysis of the material parameters of normal strength (NSC) and high strength concrete (HSC) presented in Eurocode 2 the thermo-mechanical material parameters of one representative HSC were identified. Using these parameters and based on an appropriate material model the behavior of HSC columns was simulated. The validation of the model was realized through real scale fire resistance tests on loaded columns of the same type of HSC as in the material identification tests. It was found that the strength as a characteristic parameter of the material model has to be identified on the basis of transient creep tests and not of stationary tests, respectively as realized usually for NSC. It could be shown that the structural behavior of the tested columns is overestimated if the numerical simulations are based on the material properties of HSC as proposed in. This feature is expressed especially through insufficient displacements. KW - Brandschutz KW - Verformungsverhalten KW - Hochleistungsbeton KW - Nichtlineare Berechnungsverfahren KW - Modellierung KW - EC KW - Eurocode KW - Normen KW - Berechnungs- und Bemessungsverfahren KW - Normen/Vorschriften/Richtlinien KW - Brandschutz KW - Versuche KW - Eurocode KW - Hochfester Beton KW - Feuerwiderstandsdauer KW - Finite-Elemente-Methode PY - 2012 U6 - https://doi.org/10.1002/best.201200010 SN - 0005-9900 SN - 1437-1006 VL - 107 IS - 6 SP - 372 EP - 378 PB - Ernst CY - Berlin AN - OPUS4-26100 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hauswaldt, Sebastian A1 - Korzen, Manfred A1 - Hartmann, S. ED - Fontana, M. ED - Frangi, A. ED - Knobloch, M. T1 - A continuum-mechanical model for FE-simulations of steel constructions in fire T2 - SIF 2012 - 7th International conference on structures in fire CY - Zurich, Switzerland DA - 2012-06-06 KW - Constitutive equation KW - Viscoplasticity KW - Endochronic plasticity KW - UMAT KW - Finite element method KW - Fire resistance PY - 2012 U6 - https://doi.org/10.3929/ethz-a-007050197 SP - 439 EP - 448 CY - Zurich, Switzerland AN - OPUS4-26108 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Korzen, Manfred ED - Moreyra Garlock, Maria E. ED - Kodur, Venkatesh K.R. T1 - Constitutive modeling for fire engineering purposes—The challenge of modeling creep in an appropriate way N2 - The phenomenon of creep of structural steel in fire engineering is gaining more and more interest. Due to shortcomings of the EC3 constitutive model and other approaches based on classical creep theory an alternative approach mainly based on the ideas of Krempl is proposed. Due to this so-called operator approach the material as well as the constitutive model is looked upon as an operator. The application of this view serves as a guide through the analysis of the relationship between experimental facts and constitutive theory especially in the context of transient creep. T2 - 9th International Conference on Structures in Fire CY - Princeton, NJ, USA DA - 08.06.2016 KW - Fire engineering KW - Creep KW - Constitutive equation PY - 2016 SN - 978-1-60595-320-5 SP - 608 EP - 615 PB - DEStech Publications, Inc. CY - Lancaster, PA, USA AN - OPUS4-37329 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rodrigues, J.P.C. A1 - Laím, L.M. A1 - Korzen, Manfred T1 - Fire behaviour of circular concrete columns with restrained thermal elongation N2 - Most of the previous studies on reinforced concrete columns with elastically restrained thermal elongation were carried out on square, rectangular or '+'-shaped cross sections. The number of fire resistance tests on circular reinforced concrete columns with elastically restrained thermal elongation is still very small. In order to examine the influence of several parameters on the behaviour in fire of this type of columns several fire resistance tests were carried out. The parameters tested were the load and restraint level, slenderness of the column and longitudinal reinforcement ratio. In the fire resistance tests the specimens were exposed to the ISO 834 standard fire curve and the critical time (fire resistance) and temperature and failure modes were determined. The test results showed that the spalling phenomenon may occur in circular columns and so reducing its fire resistance. The increasing of the load level led to a reduction while the increasing of the longitudinal reinforcement ratio or the decreasing of the slenderness of the columns led to an increasing of their fire resistance. The restraint level might not be much relevant on the fire resistance of circular reinforced concrete columns. KW - Fire KW - Resistance KW - Concrete KW - Circular KW - Column KW - Restraining PY - 2014 U6 - https://doi.org/10.3151/jact.12.289 SN - 1346-8014 VL - 12 IS - 9 SP - 289 EP - 298 CY - Tokyo AN - OPUS4-31611 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hörold, Andreas A1 - Schartel, Bernhard A1 - Trappe, Volker A1 - Korzen, Manfred A1 - Bünker, J. T1 - Fire stability of glass-fibre sandwich panels: The influence of core materials and flame retardants N2 - Fire resistance has become a key property for structural lightweight sandwich components in aviation, shipping, railway vehicles, and construction. The development of future composite materials and components demands adequate test procedures for simultaneous application of compression and fully developed fire. Therefore an intermediate-scale approach (specimen size = 500 mm x 500 mm) is applied with compressive loads (up to 1 MN) and direct application of a burner to one side of the specimens, as established in aviation for severe burn-through tests. The influence of different core structures (polyvinylchloride foam, polyisocyanorate foam reinforced by stitched glass bridges, and balsa wood) was investigated for glass-fibre-reinforced sandwich specimens with and without flame retardants applied on the fabrics, in the matrix, and on surface for each specimen at the same time. Times to failure were increased up to a factor of 4. The intumescent coating prolongs the time to failure significantly. What is more, using the intrinsic potential of the front skin together with the core to protect a load bearing back skin in sandwich panels, the design of the core – here using the wood core – is the most promising approach. KW - Fire resistance KW - Fire stability KW - Glass-fibre-reinforced plastics KW - Composite KW - Core materials PY - 2017 U6 - https://doi.org/10.1016/j.compstruct.2016.11.027 SN - 0263-8223 SN - 1879-1085 VL - 160 SP - 1310 EP - 1318 PB - Elsevier AN - OPUS4-38622 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hörold, Andreas A1 - Schartel, Bernhard A1 - Trappe, Volker A1 - Gettwert, V. A1 - Korzen, Manfred T1 - Protecting the structural integrity of composites in fire: Intumescent coatings in the intermediate scale N2 - The fire behaviour of light-weight material used in structural applications is regarded as the main challenge to be solved for mass transportation. The task is to perform realistic experiments, including a mechanical test scenario under fully developed fires, to improve the material's reliability in structural applications. Our approach utilises an intermediate-scale test set-up (specimen size 500 × 500 mm) to apply realistic compressive loads and fully developed fires directly to one side of a carbon-fibre-reinforced sandwich composite. Three different intumescent coatings were applied to sandwich structures and compared to a bench-scale study. The results emphasise intumescent coatings as a promising method to sustain fire resistance, multiplying the time to failure. Nevertheless, the realistic intermediate-scale test using severe direct flame application underlines the extremely short failure times when the actual composite components are tested without any additional insulation. KW - Carbon-fibre-reinforced KW - Fire stability KW - High-temperature properties KW - Mechanical testing KW - Fully developed fire KW - Post-crash scenario PY - 2015 U6 - https://doi.org/10.1177/0731684415609791 SN - 0731-6844 SN - 1530-7964 VL - 34 IS - 24 SP - 2029 EP - 2044 PB - Technomic Publ. Co. CY - Westport, Conn. AN - OPUS4-35120 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Daus, Lars-Hendrik A1 - Schartel, Bernhard A1 - Wachtendorf, Volker A1 - Mangelsdorf, R. A1 - Korzen, Manfred T1 - A chain is no stronger than its weakest link: Weathering resistance of water-based intumescent coatings for steel applications N2 - A systematic approach was used to investigate the weathering-induced degradation of a common water–based intumescent coating. In this study, the coatings are intended for humid indoor applications on steel substrates. The coating contains ammonium polyphosphate, pentaerythritol, melamine, and polyvinyl acetate. By replacing each ingredient with a less water-soluble substance, the most vulnerable substances, polyvinyl acetate and pentaerythritol, were identified. Furthermore, the weathering resistance of the system was improved by exchanging the ingredients. The coatings were stressed by artificial weathering tests and evaluated by fire tests. Thermogravimetry and Fourier-transform infrared spectroscopy were used to study the thermal decomposition. This study lays the foundation for the development of a new generation of water-based intumescent coatings. KW - Intumescence KW - Fire resistance KW - Fire protective coatings KW - Weathering KW - Thermogravimetric analyses PY - 2021 U6 - https://doi.org/10.1177/0734904120961064 SN - 0734-9041 SN - 1530-8049 VL - 39 IS - 1 SP - 72 EP - 102 PB - SAGE AN - OPUS4-52015 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Talebi, Elnaz A1 - Korzen, Manfred A1 - Espinós, A. A1 - Hothan, Sascha ED - Albero, Vicente T1 - The effect of damage location on the performance of seismically damaged concrete filled steel tube columns at fire N2 - In this paper, a nonlinear three-dimensional finite element (FE) model was developed and validated to study the effect of seismic damage location on the response of concrete filled tube (CFT) columns at fire after earthquakes. Three analyses were conducted consecutively in the modelling, namely, cyclic, thermal and structural. Results of the cyclic loading analysis comprising residual deformations were applied as the Initial condition to the thermal-stress model, replicating the seismic performance of column. Following, a nonlinear sequentially coupled-thermal stress Analysis was carried out to investigate the fire response of CFT columns after the seismic event. Three damage scenarios were contemplated, considering any possible potential damages that could be generated by the earthquake loading on CFT columns. The accuracy of the proposed FE model was examined by comparing the numerical results with that of available tests on fire and cyclic loading. By means of the validated model, the performance of damaged CFT columns was then investigated under fire after earthquakes. The level of damage was assumed as a high damage level, presuming that the column reached 50% of ist lateral resistance while still maintaining its overall stability after the earthquake. The results were presented broadly, including the axial deformation history as well as the fire resistance time for CFT columns. To have a comprehensive insight on the influence of damage location in columns, the fire response of damaged specimens was compared with that of an intact one. T2 - 12th International Conference on Advances in Steel-Concrete Composite Structures (ASCCS 2018) CY - Valencia, Spain DA - 27.06. 2018 KW - Fire after earthquake KW - Concrete filled tube (CFT) column KW - Finite element model KW - Seismically damaged column KW - Damage location KW - Fire performance PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-457694 SN - 978-84-9048-601-6 SP - 835 EP - 842 PB - Editorial Universitat Politècnica de València CY - València AN - OPUS4-45769 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Talebi, Elnaz A1 - Korzen, Manfred A1 - Hothan, Sascha T1 - The performance of concrete filled steel tube columns under postearthquake fires N2 - In this study, a nonlinear three-dimensional finite element (FE) model was developed and validated to investigate the response of concrete filled tube (CFT) columns subjected to post-earthquake fires. Three steps were considered successively in the modelling, namely, cyclic, thermal and structural analyses. Outputs from the cyclic loading including residual deformationswere imposed as an initial condition to the thermal-stress model, imitating the seismic response of the column. Subsequently, a nonlinear sequentially thermal-stress analysis was conducted to simulate the fire response of column after the earthquake. The proposed FE model was validated by comparing the simulation resultswith the observations of full-scale fire and cyclic tests available in the literature. The validated numericalmodelwas then used to study the behavior of CFT columns under the combined action of earthquake and fire as a multi-hazard event. Three probable seismic damage scenarios were considered in the column, namely, middle length, bottom and top end region damages. The level of damage was assumed as a high damage level, presuming that the column reached 50% of its lateral resistance while still maintaining ist overall stability after the earthquake. The results showed that the top and bottom end region damages have not significantly influence the fire response of the damaged column. Besides, the column with the middle span damage performed a lesser fire resistance time owing to the coincidence of damage location to that of onset of global buckling. KW - Post-earthquake fire KW - Concrete filled tube (CFT) column KW - Finite element analysis KW - Seismically damaged column KW - Fire resistance KW - Multi-hazard incident PY - 2018 U6 - https://doi.org/10.1016/j.jcsr.2018.07.013 SN - 0143-974X VL - 150 SP - 115 EP - 128 PB - Elsevier Ltd. AN - OPUS4-45813 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Timme, Sebastian A1 - Trappe, Volker A1 - Korzen, Manfred A1 - Schartel, Bernhard T1 - Fire stability of carbon fiber reinforced polymer shells on the intermediate-scale N2 - The fire stability of carbon fiber reinforced polymer (CFRP) shell structures was investigated using an intermediate-scale test setup. The shell specimens are representative of typical load-bearing CFRPs in modern civil aviation. The CFRP shell specimens were exposed to a fully developed fire with direct flame impingement to one side at a heat flux of 182 kW/m2. Specimens were simultaneously loaded with constant compressive force equal to 40% of the ultimate failure load. CFRP shells and four different fire retarding configurations, using integrated protective layers, were investigated. Unprotected CFRP specimens failed after just 27 s. Specimens with integrated protective layers with low heat conductivity and high burn-through resistance showed the most promising results. An integrated titanium foil decelerated the decomposition of the epoxy matrix and increased the time to failure by 68% compared to the unprotected CFRP shell. KW - Fire stability KW - Carbon fiber reinforced polymer (CFRP) KW - Thermomechanical properties KW - Buckling KW - Fully developed fire PY - 2017 U6 - https://doi.org/10.1016/j.compstruct.2017.07.025 SN - 0263-8223 SN - 1879-1085 VL - 178 SP - 320 EP - 329 PB - Elsevier Ltd. AN - OPUS4-41283 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pimienta, Pierre A1 - McNamee, Robert A1 - Robert, Fabienne A1 - Boström, Lars A1 - Huang, Shan-Shan A1 - Mróz, Katarzyna A1 - Davie, Colin A1 - Mohaine, Siyimane A1 - Alonso, Maria Cruz A1 - Bodnarova, Lenka A1 - Bosnjak, Josipa A1 - Dal Pont, Stefano A1 - Dao, Vinh A1 - Dauti, Dorjan A1 - Dehn, Frank A1 - Felicetti, Roberto A1 - Hager, Izabela A1 - Hela, Rudolf A1 - Hozjan, Tomaz A1 - Juknat, Michael A1 - Jumppanen, Ulla-Maija A1 - Kirnbauer, Johannes A1 - Kolsek, Jerneja A1 - Korzen, Manfred A1 - Lakhani, Hitesh A1 - Lion, Maxime A1 - Lo Monte, Francesco A1 - Maluk, Cristian A1 - Meftah, Fekri A1 - Miah, Md Jihad A1 - Millard, Alain A1 - Mindeguia, Jean-Christophe A1 - Moreau, Bérénice A1 - Msaad, Yahia A1 - Ozawa, Mitsuo A1 - Pesavento, Francesco A1 - Pham, Duc Toan A1 - Pistol, Klaus A1 - Rickard, Ieuan A1 - Rodrigues, Joao Paulo Correia A1 - Roosefid, Mohsen A1 - Schneider, Martin A1 - Sharma, Umesh Kumar A1 - Sideris, Kosmas A1 - Stelzner, Ludwig A1 - Weber, Benedikt A1 - Weise, Frank T1 - Recommendation of RILEM TC 256-SPF on fire spalling assessment during standardised fire resistance tests: complementary guidance and requirements N2 - The recommendation is based on the co-authors’ work organized by the RILEM TC 256-SPF “Spalling of concrete due to fire: testing and modelling”. It aims to provide useful information, guidance and best practices in fire spalling assessment to laboratories that perform large-scale tests based on fire resistance test standards. It provides guidance on the spalling observation techniques during testing, as well as post-test spalling quantification/assessment methods. This document is intended to be used in conjunction with the fire resistance test standards, e.g. EN 1363-1 and ISO 834-1. KW - Concrete KW - Fire spalling KW - Large scale tests KW - Standardised fire resistance tests PY - 2024 U6 - https://doi.org/10.1617/s11527-023-02248-z SN - 1871-6873 VL - 57 IS - 1 SP - 1 EP - 12 PB - Springer CY - Dordrecht AN - OPUS4-59288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -