TY - JOUR A1 - Kindrachuk, Vitaliy A1 - Fedelich, Bernard A1 - Rehmer, Birgit A1 - Peter, Frauke T1 - Computational methods for lifetime prediction of metallic components under high-temperature fatigue N2 - The issue of service life prediction of hot metallic components subjected to cyclic loadings is addressed. Two classes of lifetime models are considered, namely, the incremental lifetime rules and the parametric models governed by the fracture mechanics concept. Examples of application to an austenitic cast iron are presented. In addition, computational techniques to accelerate the time integration of the incremental models throughout the fatigue loading history are discussed. They efficiently solve problems where a stabilized response of a component is not observed, for example due to the plastic strain which is no longer completely reversed and accumulates throughout the fatigue history. The performance of such an accelerated Integration technique is demonstrated for a finite element simulation of a viscoplastic solid under repeating loading–unloading cycles. KW - Fatigue KW - Incremental lifetime models KW - Finite element analysis PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-481215 UR - https://www.mdpi.com/2075-4701/9/4/390 DO - https://doi.org/10.3390/met9040390 SN - 2075-4701 VL - 9 IS - 4 SP - 390, 1 EP - 24 PB - mdpi CY - Basel, Switzerland AN - OPUS4-48121 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krütt, Enno A1 - Weise, Frank A1 - Meng, Birgit ED - Ye, G. ED - Yuan, Y. ED - Romero Rodriguez, C. ED - Zhang, H. ED - Savija, B. T1 - Fatigue induced degradation in pavement concrete and its effect on the alkali-silica reaction N2 - In recent years the German motorway network has seen an increase in the occurrence of damage to concrete road surfaces that can be attributed to the alkali-silica reaction (ASR). In view of the often drastically reduced service life of road surfaces due to ASR, research activity in this field has notably increased. Alongside preventative measures in concrete technology i.e. the usage of low-alkali cements, the main research focus up to now has been on the development of performance-oriented testing procedures for ASR prevention. The effects of mechanicallyinduced damage resulting from cyclic traffic and climatic loading have previously not been taken into consideration. The assessment of the myriad degradation and transport processes necessary for an understanding of these effects requires close interaction between experiments and corresponding multi-scale models. This contribution is focused on the experiments utilizing innovative testing techniques. The research is founded on a series of fatigue tests performed on large-scale beams with simultaneous tracking of the degradation process using non-destructive evaluation methods. Subsequently, smaller test specimens were extracted from the predamaged beams for further experiments. These experiments included investigation of the influence of fatigue-induced cracks on moisture and alkali transport. Subsequent storage of the small-scale test specimens, with and without cyclic pre-damage, in an ASR-conducive environment then provided initial findings on the influence of fatigue-induced degradation on the ASR. The results show that the degradation process can be well observed with the test Setup developed for the fatigue experiments. Further, a small but noticeable increase of mass Transport due to fatigue-induced degradation was measured, which correspondingly indicated an increased ASR damage potential. T2 - 4th International Conference on Service Life Design for Infrastructures (SLD4) CY - Delft, The Netherlands DA - 27.08.2018 KW - Fatigue KW - Pavement KW - ASR KW - Concrete PY - 2018 SN - 978-2-35158-213-8 SP - 112 EP - 121 PB - RILEM Publication S.A.R.L. CY - Paris, France AN - OPUS4-46197 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krütt, Enno A1 - Weise, Frank A1 - Meng, Birgit T1 - Fatigue induced degradation in pavement concrete and its effect on the alkali-silica-reaction N2 - In recent years the German motorway network has seen an increase in the occurrence of damage to concrete road surfaces that can be attributed to the alkali-silica reaction (ASR). In view of the often drastically reduced service life of road surfaces due to ASR, research activity in this field has notably increased. Alongside preventative measures in concrete technology i.e. the usage of low-alkali cements, the main research focus up to now has been on the development of performance-oriented testing procedures for ASR prevention. The effects of mechanicallyinduced damage resulting from cyclic traffic and climatic loading have previously not been taken into consideration. The assessment of the myriad degradation and transport processes necessary for an understanding of these effects requires close interaction between experiments and corresponding multi-scale models. This contribution is focused on the experiments utilizing innovative testing techniques. The research is founded on a series of fatigue tests performed on large-scale beams with simultaneous tracking of the degradation process using non-destructive evaluation methods. Subsequently, smaller test specimens were extracted from the predamaged beams for further experiments. These experiments included investigation of the influence of fatigue-induced cracks on moisture and alkali transport. Subsequent storage of the small-scale test specimens, with and without cyclic pre-damage, in an ASR-conducive environment then provided initial findings on the influence of fatigue-induced degradation on the ASR. The results show that the degradation process can be well observed with the test Setup developed for the fatigue experiments. Further, a small but noticeable increase of mass Transport due to fatigue-induced degradation was measured, which correspondingly indicated an increased ASR damage potential. T2 - 4th International Conference on Service Life Design for Infrastructures (SLD4) CY - Delft, The Netherlands DA - 27.08.2018 KW - Fatigue KW - Pavement KW - ASR KW - Concrete PY - 2018 AN - OPUS4-46199 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Olbricht, Jürgen A1 - Jürgens, Maria A1 - Agudo Jácome, Leonardo A1 - Nolze, Gert A1 - Roohbakhshan, Farshad A1 - Fedelich, Bernard A1 - Skrotzki, Birgit T1 - Cyclic loading and creep-fatigue performance of P92 N2 - 9-12% Cr ferritic-martensitic stainless steels are widely used as high temperature construction materials in power plants due to their excellent creep and oxidation resistance. The growing share of renewable energy sources in power generation forces many of these plants into more flexible operation with frequent load shifts or shutdowns. These cyclic operation profiles constitute a major lifetime issue. The present contribution reports on current findings obtained in a multidisciplinary project which combines cyclic mechanical and cyclic oxidation testing of different 9-12% Cr grades with detailed microstructural analyses. Mechanical analyses are carried out on P92 and P91 steel grades to give an overview of softening phenomena and lifetimes obtained in isothermal cyclic loading (low cycle fatigue, LCF), non-isothermal cyclic loading (thermo-mechanical fatigue, TMF), and service-like combinations of creep and fatigue periods. Complementary microstructural investigations by scanning and transmission electron microscopy plus EBSD are used for phase identification, substrate/oxide interface characterization and quantification of the microstructure evolution under cyclic conditions. T2 - 44th MPA-Seminar CY - Leinfelden/Stuttgart, Germany DA - 17.10.2018 KW - Ferritic-martensitic steels KW - Fatigue KW - Creep-fatigue PY - 2018 AN - OPUS4-47116 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker A1 - Kraus, David A1 - Kübler, Stefan A1 - Eisermann, René T1 - Multiaxial fatigue damage of glass fiber reinforced polymers N2 - Fiber reinforced polymers (FRPs) are a well established material in lightweight applications, e.g. in automotive, aerospace or wind energy. The FRP components are subjected to multiaxial mechanical as well as hygrothermal loads. Common operation temperatures are in the range of 213 K and 373 K (-60 °C and 100 °C) at a relative humidity of 10% to 90%. In spacecraft applications, the environmental conditions are even more extreme. However, the correlation between multiaxial mechanical loading and harsh environment conditions have to-date not been investigated in detail. The project aims to investigate the fatigue behavior of FRPs dependent on multiaxial mechanical loading, temperature, and humidity. Extensive experimental testing is performed on flat plate and cylindrical tube specimens, accompanied by numerical and analytical calculations. T2 - 24. Nationales SAMPE Symposium CY - Dresden, Germany DA - 06.02.2019 KW - Composite KW - Fatigue KW - Thermomechanics KW - Distributed fiber optic sensors PY - 2019 AN - OPUS4-47335 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kindrachuk, Vitaliy A1 - Unger, Jörg F. T1 - A novel computational method for efficient evaluation of structural fatigue N2 - The methods of computational damage mechanics are well-established for the description of degradation of materials under monotone loading. An extension to structural damage induced by cyclic loading is however significantly limited. This is due to enormous computational costs required to resolve each load cycle by conventional temporal incremental integration schemes while a typical fatigue loading history comprises between thousands and millions of cycles. Despite the permanent increase of computational resources and algorithmic performance, a successful approach is rather based on the development of novel multiscale in time integration schemes. A Fourier transformation-based temporal integration (FTTI) is represented, which takes advantage of temporal scale separation incorporated into the cycle jump method. The response fields are approximated by a Fourier series whose coefficients undergo the evolution on a long-time scale. This is correlated with the evolution of the history variables, including damage, by means of the adaptive cycle jump method of various orders. The necessary extrapolation rates are obtained from the underlying solution of a short-time scale problem, which results from the oscillatory boundary condition and fulfills the global equilibrium of the Fourier coefficients. In this way, a remarkable speedup is achieved because the number of cycles to be fully integrated dramatically decreases. The key idea behind the FTTI method is that the global in space equilibrium problem is linear since it is decoupled from the evolution equations. The latter are solved in the quadrature points under response fields prescribed throughout the whole load cycle. Consequently, integration of a single load cycle is much more efficient than the conventional single scale integration where the global equilibrium iteration and the local iteration of the evolution equations are coupled. This results in an additional speedup of the FTTI method. The performance of the FTTI technique is demonstrated for two different constitutive behaviors: a viscoplastic model with a damage variable governed by the local equivalent viscoplastic strain; a quasi-brittle response where the damage variable is driven by a non-local equivalent strain. The latter is implicitly introduced as proposed by Peerlings. Both, the explicit and implicit extrapolation schemes are validated. The FTTI solutions agree very well with the reference cycle-by -cycle solutions, while significantly reducing the computational costs. The adaptive determination of the jump length can properly recognize the particular responses throughout the fatigue loading history (stationary fatigue, acceleration of fatigue damage when approaching failure) as well as stress redistribution phenomena. T2 - International Fatigue International Fatigue International Fatigue International Fatigue International Fatigue International Fatigue Congress Congress Congress 2018 CY - Poitiers, France DA - 27.05.2018 KW - Fatigue KW - Accelerated integration scheme PY - 2018 AN - OPUS4-46975 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Frei, Vivian A1 - Thiele, Marc A1 - Pirskawetz, Stephan A1 - Meng, Birgit A1 - Rogge, Andreas T1 - Characterizing the Fatigue Behavior of High-Performance Concrete for Wind Energy Structures N2 - Severe mechanical fatigue conditions for worldwide proliferating windfarms are a Major challenge for high-performance concrete in towers, connecting joints and foundations of wind turbines. High-performance concrete offers potential for the application in offshore windfarms, not only regarding its good mechanical, but also chemical resistivity due to low diffusivity in the highly densified microstructure. For a more reliable fatigue assessment, monitoring based on nondestructive testing can be a valuable complement to design rules. Both approaches demand reliable experimental data, information about scalability and the development of standardized testing methods. This article presents results of an ongoing research program of BAM (Bundesanstalt für Materialforschung und -prüfung), which is a part of a joint national project (WinConFat) funded by the German Federal Ministry for Economic Affairs and Energy. The subproject implemented by BAM examines the fatigue behavior in dependence of size and slenderness for varying concrete strength at different stress levels. Besides fatigue strength, nondestructive testing is carried out additionally. Methods used are strain measurement and ultrasonic testing. The change of strain, stiffness and ultrasonic pulse velocity in the fatigue process is discussed. Results disclose a deeper insight into the damage process under cyclic loading of high-performance concrete and contribute to improve nondestructive monitoring. T2 - LORCENIS - Long Lasting Reinforced Concrete for Energy Infrastructue under Severe Operating Conditions CY - Gent, Belgium DA - 10.09.2019 KW - Compressive Cyclic loading KW - Fatigue KW - High-strength concrete KW - Non destructive testing KW - Ultrasonic testing PY - 2019 AN - OPUS4-49474 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Frei, Vivian A1 - Thiele, Marc A1 - Pirskawetz, Stephan A1 - Meng, Birgit A1 - Rogge, Andreas T1 - Characterizing the Fatigue Behavior of High-Performance Concrete for Wind Energy Structures N2 - Severe mechanical fatigue conditions for worldwide proliferating windfarms are a Major challenge for high-performance concrete in towers, connecting joints and foundations of wind turbines. High-performance concrete offers potential for the application in offshore windfarms, not only regarding its good mechanical, but also chemical resistivity due to low diffusivity in the highly densified microstructure. For a more reliable fatigue assessment, monitoring based on nondestructive testing can be a valuable complement to design rules. Both approaches demand reliable experimental data, information about scalability and the development of standardized testing methods. This article presents results of an ongoing research program of BAM (Bundesanstalt für Materialforschung und -prüfung), which is a part of a joint national project (WinConFat) funded by the German Federal Ministry for Economic Affairs and Energy. The subproject implemented by BAM examines the fatigue behavior in dependence of size and slenderness for varying concrete strength at different stress levels. Besides fatigue strength, nondestructive testing is carried out additionally. Methods used are strain measurement and ultrasonic testing. The change of strain, stiffness and ultrasonic pulse velocity in the fatigue process is discussed. Results disclose a deeper insight into the damage process under cyclic loading of high-performance concrete and contribute to improve nondestructive monitoring. T2 - LORCENIS - Long Lasting Reinforced Concrete fpr Energy Infrastructure under Severe Operating Conditions CY - Ghent, Belgium DA - 10.09.2019 KW - Compressive Cyclic loading KW - Fatigue KW - High-strength concrete KW - Non destructive testing KW - Ultrasonic testing PY - 2019 SN - 978-9-463-88638-3 SP - 1 EP - 4 AN - OPUS4-49500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hilgenberg, Kai A1 - Daum, Werner A1 - Maierhofer, Christiane A1 - Altenburg, Simon A1 - Bruno, Giovanni A1 - Heckel, Thomas A1 - Skrotzki, Birgit A1 - Zerbst, Uwe A1 - Kranzmann, Axel A1 - Bettge, Dirk A1 - Sommer, Konstantin A1 - Seeger, Stefan A1 - Nitsche, Michael A1 - Günster, Jens A1 - Evans, Alexander T1 - Additive manufacturing at the BAM: We focus on Safety N2 - In Germany, the Federal Institute for Materials Research and Testing (BAM) is addressing challenges in the implementation of additive manufacturing on the industrial landscape for safety-critical applications. KW - Process development KW - Additive Manufacturing KW - In-situ Process Monitoring KW - Non-destructive Materials KW - Characterisation KW - Safety KW - Fatigue KW - Environment KW - Standardisation PY - 2019 UR - https://static.asminternational.org/amp/201910/22/ SN - 0882-7958 VL - 177 IS - 7 SP - 22 EP - 26 PB - ASM International CY - Materials Park, OH, USA AN - OPUS4-49780 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Evans, Alexander A1 - Mohr, Gunther A1 - Hilgenberg, Kai A1 - Straße, Anne A1 - Gumenyuk, Andrey A1 - Winterkorn, René A1 - Pittner, Andreas A1 - Sommer, Konstantin A1 - Bettge, Dirk A1 - Kranzmann, Axel A1 - Nolze, Gert A1 - Avila, Luis A1 - Rehmer, Birgit A1 - Charmi, Amir A1 - Falkenberg, Rainer A1 - Skrotzki, Birgit A1 - Werner, Tiago A1 - Madia, Mauro A1 - Zerbst, Uwe A1 - Ulbricht, Alexander A1 - Sprengel, Maximilian A1 - Kromm, Arne A1 - Thiede, Tobias A1 - Bruno, Giovanni T1 - Ageing in additively manufactured metallic components: from powder to mechanical failure” an overview of the project agil N2 - An overview of the BAM funed Focus Area Materials Project "AGIL" will be presented. AGIL focussed on the stdiy of the ageing characteristics of additively manufactured austenitic stainless steel with a "powder to mechanical failure" Approach. Recent Highlights are presented and a perspective for future studies. T2 - Workshop on Additive Manufacturing CY - BAM, Berlin, Germany DA - 13.05.2019 KW - Residual stress KW - Additive Manufacturing KW - Non-destructive testing KW - Microstructure characterisation KW - Tensile testing KW - Fatigue KW - Crystal Plasticity Modelling KW - Crack propagation PY - 2019 AN - OPUS4-49823 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -