TY - CONF A1 - Pirskawetz, Stephan A1 - Zaripova, Gulshat A1 - Brinkmann, Nienke A1 - Gebraad, Lars A1 - Boehm, Christian A1 - Trattnig, Horst T1 - Simulation der Schallemissionen von Spanndrahtbrüchen N2 - In den 1950er Jahren setzte sich die Spannbetonbauweise für Brücken mit größeren Spannweiten durch. Heute existieren im deutschen Bundesfernstraßennetz ca. 21.000 Spannbetonbrücken. Die mangelnde Erfahrung in der Anfangszeit dieser Bauweise stellt uns heute vor Probleme hinsichtlich einer Kombination aus Korrosion und Ermüdung der Spannglieder. Hauptursachen sind Spannungsrisskorrosion, deutlich gewachsene Verkehrslasten sowie ungenügende Annahmen zu Temperaturlasten. Insbesondere Spanndrahtbrüche infolge Spannungsrisskorrosion können zu einem Strukturversagen ohne Ankündigung führen. Spannstähle mit einer starken Gefährdung für Spannungsrisskorrosion wurden in der Bundesrepublik bis 1965, in der ehemaligen DDR bis Ende der 1980er Jahre verbaut. Um katastrophale Schadensfälle zu verhindern, müssen Bauwerke unter Verdacht auf Spannungsrisskorrosion in Kombination mit unzureichendem Ankündigungsverhalten überwacht werden. Derzeit ist die Schallemissionsanalyse die einzige zuverlässige und ökonomisch vertretbare Überwachungsmethode. Damit kann der sichere Betrieb der Bauwerke über die verbleibende Nutzungsdauer gewährleistet werden. Die DGZfP-Richtlinie SE05 “Detektion von Spanndrahtbrüchen mit Schallemissionsanalyse” beschreibt detailliert Planung, Installation und Betrieb solcher Monitoringsysteme. Im Projekt SimAS “Digitaler Zwilling zur Simulation der Ausbreitung akustischer Wellen in Spannbetonelementen” werden die Grundlagen für eine Optimierung der Monitoringsysteme auf Basis der Schallemissionsanalyse gelegt. Eine akustische Simulation der Struktur und deren Fusion mit Messdaten unterstützt sowohl die vorbereitenden akustischen Analysen der Brücken als auch die Planung der Monitoringsysteme und die Drahtbrucherkennung T2 - SCHALL 25 – Schallemissionsanalyse und Zustandsüberwachung mit geführten Wellen CY - Dresden, Germany DA - 27.03.2025 KW - Acoustic Emission KW - Simulation KW - Schallemission KW - Spannbetonbrücke KW - Spanndrahtbruch KW - Digitaler akustischer Zwilling KW - Spannungsrisskorrosion KW - Schallemissionsanalyse KW - Schallausbreitung PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-628347 DO - https://doi.org/10.58286/30964 VL - 4 SP - 1 EP - 6 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung AN - OPUS4-62834 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pelkner, Matthias A1 - Erthner, Thomas A1 - Reimund, Verena A1 - Kreutzbruck, Marc A1 - Sergeeva-Chollet, N. T1 - MR-based eddy current probe design for hidden defects N2 - We present a simulation study which pursues the objective to find probe geometries for a MR-based eddy current (EC) probe (MR magneto resistance, e.g., GMR giant magneto resistance, TMR tunnel magneto resistance). MR sensor technology exhibits two significant advantages compared with conventional coil systems. First, MR sensors are relatively frequency-independent within common EC-frequency ranges which enable us to operate them in hidden defects testing problems. Secondly, MR technology is well suited for miniaturization helping us to design small elements in the order of below 100 µm. In this paper simulation and experimental results obtained with the probes for low frequency application, i.e. for hidden defects detection are discussed. Our simulations are based on two different approaches for a better validation, a commercial finite element method software (Opera, Vectorfields) and the semi-analytical software CIVA. We investigated both coil arrangement in order to excite sufficient high eddy currents inside the test samples and position of MR-elements at the array chip. In doing so the MR sensors were positioned that they are not exposed to excitation fields. In addition, different coil geometries, in particular coil length, e.g. Ι = 20 mm, were analyzed in order to generate a consistent eddy current distribution beneath an array of up to 32 MR-elements. To prove obtained probe principles we built GMR-EC-probes. The first test measurements are in good agreement with the simulations performed by BAM and CEA. On basis of our findings the IMAGIC consortium developed new MR-EC-probes using integrated ASIC technology. T2 - ECNDT 2014 - 11th European conference on non-destructive testing CY - Prague, Czech Republic DA - 06.10.2014 KW - Magneto resistance (MR) KW - Eddy current (EC) KW - Simulation KW - GMR KW - Magnetic flux leakage KW - Hidden defects PY - 2014 UR - http://www.ndt.net/events/ECNDT2014/app/content/Paper/409_Pelkner.pdf SN - 978-80-214-5018-9 SP - 1 EP - 8 AN - OPUS4-32231 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Boehm, Rainer A1 - Erhard, Anton T1 - Modelling of reflectivity patterns from artificial defects T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 KW - NDT KW - Ultrasound KW - Simulation KW - Reflectivity KW - Focussing KW - SAFT KW - Imaging PY - 2006 SN - 3-931381-86-2 SP - 1 EP - 10(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-14057 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geier, M. A1 - Eberstein, M. A1 - Grießmann, H. A1 - Partsch, U. A1 - Völkel, L. A1 - Böhme, R. A1 - Mann, Guido A1 - Bonse, Jörn A1 - Krüger, Jörg T1 - Impact of laser treatment on phosphoric acid coated multicrystalline silicon PV-wafers N2 - The selective emitter is a well-known technology for producing highly doped areas under the metallization grid to improve the solar cell performance. In this work, the influence of laser irradiation on phosphoric acid coated multicrystalline silicon PV-wafers on the wafer surface structure, the phosphorous depth distribution and the electrical contact resistance within the laser treated area as well as the electrical series resistance of laserprocessed solar cells was evaluated. Different laser processing settings were tested including pulsed and continuous wave (cw) laser sources (515 nm, 532 nm, 1064 nm wavelength). Complementary numerical simulations using the finite element method (FEM) were conducted to explain the impact of the laser parameters on the melting behavior (melt duration and geometry). It was found that the melt duration is a key parameter for a successful laser Doping process. Our simulations at a laser wavelengths of 515 nm reveal that low-repetition rate (<500 kHz) laser pulses of 300 ns duration generate a melt duration of ~0.35 µs, whereas upon scanning cw-laser radiation at 532 nm prolongates the melt duration by at least one order of magnitude. Experimentally, the widely used ns-laser pulses did not lead to satisfying laser irradiation results. In contrast, cw-laser radiation and scan velocities of less than 2 m/s led to suitable laser doping featuring low electrical resistances in the laser treated areas. T2 - 26th European photovoltaic solar energy conference and exhibition CY - Hamburg, Germany DA - 05.09.2011 KW - Silicon solar cell KW - Selective emitter KW - Laser processing KW - Doping KW - Simulation PY - 2011 SN - 3-936338-27-2 DO - https://doi.org/10.4229/26thEUPVSEC2011-2BV.1.7 SP - 1243 EP - 1247 AN - OPUS4-24995 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gravenkamp, Hauke A1 - Saputra, A. A. A1 - Song, C. A1 - Prager, Jens ED - Linde, B. B. J. ED - Paczkowski, J. ED - Ponikwicki, N. T1 - Detection of defects in thin-walled structures by means of lamb waves N2 - In this paper the Scaled Boundary Finite Element Method (SBFEM) is applied for the simulation of Lamb waves in cracked plates. This method is highly advantageous to study the interaction of different Lamb wave modes with cracks as the crack is not discretized and no refinement is required around the crack tip. Numerical examples are presented for the reflection of the fundamental symmetric and antisymmetric modes from cracks of different depth. The spatial Fourier transformation is employed to calculate the amplitudes of reflected Lamb wave modes. The results reveal possibilities to obtain details of the crack geometry in non-destructive testing and structural health monitoring applications. T2 - International congress on ultrasonics CY - Gdansk, Poland DA - 05.09.2011 KW - Lamb waves KW - Scaled boundary finite element method KW - Simulation KW - Crack detection PY - 2012 SN - 978-0-7354-1019-0 DO - https://doi.org/10.1063/1.3703223 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 1433 SP - 443 EP - 446 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-26203 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gollwitzer, Christian A1 - Bellon, Carsten A1 - Deresch, Andreas A1 - Ewert, Uwe A1 - Jaenisch, Gerd-Rüdiger A1 - Zscherpel, Uwe A1 - Mistral, Q. ED - Thompson, D. O. ED - Chimenti, D. E. T1 - Simulation supported POD for RT test case - concept and modeling N2 - Within the framework of the European project PICASSO, the radiographic simulator aRTist (analytical Radiographic Testing inspection simulation tool) developed by BAM has been extended for reliability assessment of film and digital radiography. NDT of safety relevant components of aerospace industry requires the proof of probability of detection (POD) of the inspection. Modeling tools can reduce the expense of such extended, time consuming NDT trials, if the result of simulation fits to the experiment. Our analytic simulation tool consists of three modules for the description of the radiation source, the interaction of radiation with test pieces and flaws, and the detection process with special focus on film and digital industrial radiography. It features high processing speed with near–interactive frame rates and a high level of realism. A concept has been developed as well as a software extension for reliability investigations, completed by a user interface for planning automatic simulations with varying parameters and defects. Furthermore, an automatic image analysis procedure is included to evaluate the defect visibility. The radiographic modeling from 3D CAD of aero engine components and quality test samples are compared as a precondition for real trials. This enables the evaluation and optimization of film replacement for application of modern digital equipment for economical NDT and defined POD. T2 - 38th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Burlington, VT, USA DA - 2011-07-17 KW - X-ray imaging KW - Probability of detection KW - Simulation KW - ZfP KW - Radiographie KW - POD PY - 2012 SN - 978-0-7354-1013-8 DO - https://doi.org/10.1063/1.4716283 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 31 IS - 1430 SP - 605 EP - 612 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-26696 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bachmann, Marcel A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Welding with high-power lasers: trends and developments N2 - High-power laser beam welding became new stimuli within the last 10 years due to the availability of a new generation of high brightness multi kilowatt solid state lasers. In the welding research new approaches have been developed to establish reliable and praxis oriented welding processes meeting the demands of modern industrial applications during this time. The paper focuses on some of the current scientific and technological aspects in this research field like hybrid laser arc welding, simulation techniques, utilization of electromagnetic fields or reduced pressure environment for laser beam welding processes, which contributed to the further development of this technology or will play a crucial role in its further industrial implementation. T2 - 9th International Conference on Photonic Technologies - LANE 2016 CY - Fürth, Germany DA - 19.09.2016 KW - High-power Laserbeam Welding KW - Electromagnetic Force KW - Vacuum KW - Simulation PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-377280 DO - https://doi.org/10.1016/j.phpro.2016.08.003 VL - 83 SP - 15 EP - 25 PB - Elsevier B.V. CY - Berlin, Germany AN - OPUS4-37728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Deresch, Andreas A1 - Jaenisch, Gerd-Rüdiger A1 - Bellon, Carsten T1 - A fast general spectrum model for quantitative radiography simulation N2 - One essential step on the way towards accurate quantitative simulation of radiographic testing is an accurate description of the utilized energy spectrum of X-ray photons. For use in general purpose simulation tools, the spectra of X-ray tubes have to be described by a model covering at least the intended range of applications. This range includes transmission tubes as well as direct beam tubes with varying angles of incidence and emission, for a number of typical target materials. In radiographic testing acceleration voltages frequently reach up to 450 kV for direct beam targets and up to 225 kV for transmission targets, with even higher voltages available or being developed. Currently used models are unable to cover the whole range of configurations. Here a model is presented that employs a unified approach for simulating the photon energy spectra for transmission and direct beam targets composed of arbi-trary homogeneous materials. In order to achieve this, a detailed model of electron transport within the target is employed. The validity of the developed model is shown through comparisons with Monte Carlo simulations as well as measurements for a number of different configurations. T2 - 19th World Conference on Nondestructive Testing CY - Munich, Germany DA - 13.06.2016 KW - Measurements KW - X-ray spectra KW - Simulation KW - Electron transport PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-365959 SN - 978-3-940283-78-8 VL - 158 SP - 1 EP - 7 PB - DGZfP CY - Berlin, Germany AN - OPUS4-36595 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaenisch, Gerd-Rüdiger A1 - Bellon, Carsten A1 - Ewert, Uwe ED - Thompson, D. O. T1 - Reliability assessment by simulation for high energy radiography T2 - 33th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Portland, OR, USA DA - 2006-07-30 KW - Simulation KW - Radiography KW - CAD KW - Probability of Detection PY - 2007 SN - 978-0-7354-0399-4 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 894 SP - 1831 EP - 1838 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-15696 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaenisch, Gerd-Rüdiger A1 - Bellon, Carsten A1 - Schumm, A. A1 - Tabary, J. A1 - Duvauchelle, P. ED - Thompson, D. O. ED - Chimenti, D. E. T1 - A proposed benchmark problem for scatter calculations in radiographic modelling T2 - 35th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Chicago, IL, USA DA - 2008-07-20 KW - Radiography KW - Justifications or modifications of Monte Carlo methods KW - Emission KW - Absorption, and scattering of electromagnetic radiation KW - X-ray scattering KW - Radiographie KW - Simulation KW - Benchmark KW - Monte Carlo Verfahren KW - Streustrahlung PY - 2009 SN - 978-0-7354-0629-2 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 1096 SP - 1930 EP - 1937 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-20134 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaenisch, Gerd-Rüdiger A1 - Bellon, Carsten A1 - Schumm, A. A1 - Tabary, J. A1 - Duvauchelle, P. ED - Thompson, D.O. ED - Chimenti, D.E. T1 - Radiographic benchmark problem 2009 - scatter calculations in modelling T2 - 36th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Kingston, RI, USA DA - 2009-07-26 KW - Radiography KW - Justifications or modifications of Monte Carlo methods KW - Emission KW - Absorption and scattering of electromagnetic radiation KW - X-ray scattering KW - Simulation KW - Röntgenspektrum Benchmark KW - Monte Carlo Modell PY - 2010 SN - 978-0-7354-0748-0 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1211 SP - 2117 EP - 2124 CY - Melville, NY AN - OPUS4-21137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zhukovskiy, M. A1 - Skachkov, M. A1 - Deresch, Andreas A1 - Jaenisch, Gerd-Rüdiger A1 - Bellon, Carsten ED - Thompson, D.O. ED - Chimenti, D.E. T1 - Simulation of electron transport T2 - 36th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Kingston, RI, USA DA - 2009-07-26 KW - Electron transport KW - Monte Carlo method KW - Stopping power KW - Simulation KW - Elektronentransport PY - 2010 SN - 978-0-7354-0748-0 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1211 SP - 572 EP - 578 CY - Melville, NY AN - OPUS4-21134 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Deresch, Andreas A1 - Jaenisch, Gerd-Rüdiger A1 - Bellon, Carsten A1 - Warrikhoff, A. ED - Thompson, D.O. ED - Chimenti, D.E. T1 - Simulation and experimental verification of X-ray spectra T2 - 36th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Kingston, RI, USA DA - 2009-07-26 KW - X-ray KW - Spectrum KW - Simulation KW - Röntgenspektrum KW - Dekonvolution PY - 2010 SN - 978-0-7354-0748-0 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1211 SP - 535 EP - 540 CY - Melville, NY AN - OPUS4-21136 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaenisch, Gerd-Rüdiger A1 - Deresch, Andreas A1 - Bellon, Carsten A1 - Ewert, Uwe A1 - Przybilla, Waldemar ED - Thompson, D.O. ED - Chimenti, D.E. T1 - Measurement and modeling of scatter ratios at high energies N2 - Determining scatter ratios at high energies (> ~ 1MeV) presents challenges not immediately obvious from measurements at conventional X-ray energies. This includes reduced attenuation even in heavy elements as well as a stronger forward bias of scattering. In order to check the reliability of different measurement setups with regard to material thicknesses, distances, and collimation, attenuation and scattering were separately simulated using a Monte Carlo model. The simulation results help in understanding the sources of radiation scattered into the detection area, thereby aiding in eliminating undesired contributions. T2 - 37th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - San Diego, CA, USA DA - 18.07.2010 KW - Radiography KW - Optimisation KW - X-ray detection KW - Simulation KW - High energy KW - Co-60 KW - Modeling KW - Scatter PY - 2011 SN - 978-0-7354-0888-3 DO - https://doi.org/10.1063/1.3591895 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 1335 SP - 517 EP - 524 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-25358 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten A1 - Deresch, Andreas A1 - Gollwitzer, Christian A1 - Jaenisch, Gerd-Rüdiger T1 - Radiographic simulator aRTist: version 2 N2 - Computer simulation of radiography can be used for different purposes in NDT, such as qualification of NDT systems, optimization of radiographic parameters, feasibility analysis, model-based data interpretation, and training of NDT/NDE personnel. BAM has been working on modeling in the field of radiographic testing for many years. With the gathered theoretical background and the familiarity with practical requirements of industrial application the simulation software aRTist has been developed. This analytical simulator includes a description of the radiation source, the interaction of radiation with test pieces and flaws, and the detection process with special focus on film and digital industrial radiology. It features high processing speed with nearinteractive frame rates and a high level of realism. Here we focus on the recent developments of the simulator, notably the release of aRTist version 2. Extended functionality regarding automated virtual computed tomography now allows for arbitrary scan paths. Another program extension supports reliability investigations and provides a user interface for planning automatic simulations with varying parameters and defects. T2 - 18th WCNDT - World conference on nondestructive testing CY - Durban, South Africa DA - 16.04.2012 KW - X-ray imaging KW - Radiographic testing KW - Simulation KW - Computed tomography PY - 2012 SN - 978-0-620-52872-6 SP - 1 EP - 7 (Paper 333) AN - OPUS4-27398 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Deresch, Andreas A1 - Jaenisch, Gerd-Rüdiger A1 - Bellon, Carsten A1 - Warrikhoff, A. T1 - Simulating X-ray spectra: from tube parameters to detector output N2 - A model is discussed which describes the generation of X-rays in conventional tubes using tabulated bremsstrahlung energy spectra depending on three variables: the target atomic number, the incident electron kinetic energy, and the fraction of energy radiated. Additionally a parameter-free description of the characteristic radiation is included. The constructed model includes technical tube parameters like kilovoltage, target material, and angles of electron incidence and photon emission to also account for self-absorption in the target, as well as radiographic parameters like filtering. In order to verify model results, detector response is also considered. The validity of the proposed model is shown by measurements. Future work includes the extension of the model to transmission targets. This research was supported by the German Federal Ministry of Economics and Technology under contract MNPQ transfer II D 5-30/06. T2 - 18th WCNDT - World conference on nondestructive testing CY - Durban, South Africa DA - 2012-04-16 KW - X-ray KW - Spectrum KW - Simulation PY - 2012 SN - 978-0-620-52872-6 SP - 1 EP - 8 (Paper 336) AN - OPUS4-27399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gollwitzer, Christian A1 - Bellon, Carsten A1 - Deresch, Andreas A1 - Jaenisch, Gerd-Rüdiger A1 - Baron, H.-U. A1 - Ewert, Uwe T1 - Reliability investigations of radiographic testing using aRTist as a simulation tool N2 - Within the framework of the European project PICASSO, the radiographic simulator aRTist (analytical Radiographic Testing inspection simulation tool) developed by BAM has been extended for reliability assessment of film and digital radiography. A simulation supported probability of detection (POD) methodology has been developed and the validity of the approach has been studied using an application from the aeronautics industry. An experimental POD has been determined with the help of a specialized software tool, developed to aid with the collection of large series of POD data. The resulting POD is compared to simulations of the same setting using aRTist and the newly available module for simulation supported POD. A quantitative agreement within a few percent is achieved between the experimental and the simulation supported POD. T2 - 18th WCNDT - World conference on nondestructive testing CY - Durban, South Africa DA - 2012-04-16 KW - X-ray imaging KW - Probability of detection KW - Simulation PY - 2012 SN - 978-0-620-52872-6 SP - 1 EP - 10 (Paper 338) AN - OPUS4-27400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaenisch, Gerd-Rüdiger A1 - Deresch, Andreas A1 - Bellon, Carsten A1 - Schumm, A. A1 - Guerin, P. ED - Chimenti, D.E. ED - Bond, L.J. ED - Thompson, D.O. T1 - A proposed benchmark for simulation in radiographic testing N2 - The purpose of this benchmark study is to compare simulation results predicted by various models of radiographic testing, in particular those that are capable of separately predicting primary and scatter radiation for specimens of arbitrary geometry. T2 - 40th Annual review of progress in quantitative nondestructive evaluation CY - Baltimore, Maryland, USA DA - 21.07.2013 KW - Benchmark KW - Simulation KW - Radiographic testing PY - 2014 SN - 978-0-7354-1212-5 SN - 978-0-7354-1211-8 DO - https://doi.org/10.1063/1.4865082 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1581 SP - 2101 EP - 2106 PB - AIP Publishing AN - OPUS4-30756 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ewert, Uwe A1 - Deresch, Andreas A1 - Bellon, Carsten A1 - Jaenisch, Gerd-Rüdiger ED - Chimenti, D.E. ED - Bond, L.J. ED - Thompson, D.O. T1 - A benchmark concept for simulation in radiographic testing N2 - The new standard ISO 17636–2:2013 'NDT of welds: Radiographic testing - Part 2: X- and gamma ray techniques with digital detectors' describes a complex procedure for film replacement by phosphor imaging plates and digital detector arrays. RT modeling software should consider these detector types, X-ray film, and the standard requirements for image quality. Practitioners expect the same visibility of image quality indicators (IQI) in the simulated radiographs as in the experimental exposures. The proposed benchmark test is based on the comparison of experimental radiographs taken at BAM with modeled ones of participants. The experimental setup and the determination of the equivalent penetrameter sensitivity (EPS) as described in the procedure of ASTM E 746 are used for quantitative evaluation of the achievable contrast sensitivity for step hole IQIs as considered in Annex B of ISO 17636-2. System classification data for Computed Radiography (CR) and film systems will be provided by BAM according to ISO 11699–1 for selected film systems and according to ASTM E 2446 for selected CR systems. The classification of films and digital detectors is based on the measurement of the dose response function, the basic spatial resolution (SRb) of the image, and the measured image noise, which depends on the detector efficiency, the quantum statistics, and the detector fixed pattern noise. T2 - 40th Annual review of progress in quantitative nondestructive evaluation CY - Baltimore, Maryland, USA DA - 21.07.2013 KW - Digital radiography KW - Computed radiography KW - Benchmark KW - EPS KW - Modeling KW - Simulation KW - Contrast to noise ratio KW - Observer model PY - 2014 SN - 978-0-7354-1212-5 SN - 978-0-7354-1211-8 DO - https://doi.org/10.1063/1.4865044 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 33A SP - 1816 EP - 1823 PB - AIP Publishing AN - OPUS4-30904 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bearce, R.G. A1 - Mooney, M.A. A1 - Niederleithinger, Ernst A1 - Revil, A. T1 - Characterization of simulated soilcrete column curing using acoustic tomography N2 - Implementation of soilcrete columns via jet grouting or deep soil mixing to stabilize problematic subsurface soils is common in underground construction. However, industry is faced with limited options to characterize column geometry and quality of the resulting soilcrete without excavation or destructive testing. Laboratory-scale experiments were conducted on simulated soilcrete columns using crosshole ultrasonic testing to evaluate the feasibility of acoustic tomography to characterize soilcrete geometry and quality. Data were acquired on multiple columns immediately after placement up to a curing time of 120 hours. Jet grout compressional wave velocity (VP) was estimated using a first arrival time approach and inverted to construct acoustic tomograms. Acoustic tomograms indicate that crosshole ultrasonic testing is able to characterize the changes in acoustic properties that result from jet-grout curing, locate contrasts between weaker/stronger regions in the jet grout, and estimate geometry of the column. T2 - Geo-congress 2014 CY - Atlanta, Georgia, USA DA - 23.02.2014 KW - Jet grouting KW - Ultrasound KW - Tomography KW - Ray tracing KW - Simulation PY - 2014 SN - 978-0-7844-1327-2 DO - https://doi.org/10.1061/9780784413272.044 N1 - Serientitel: Geotechnical Special Publication (GSP) – Series title: Geotechnical Special Publication (GSP) VL - 234 SP - 465 EP - 474 AN - OPUS4-32601 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Numerical Simulation of Non-Destructive Foundation Pile Tests T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 KW - NDT KW - Foundation KW - Pile KW - Integrity testing KW - Parallel seismics KW - Numerical KW - CEFIT KW - Simulation PY - 2006 UR - http://www.ndt.net/article/ecndt2006/doc/P17.pdf SN - 3-931381-86-2 SP - 1(?) EP - 8(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-14213 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brauser, Stephan A1 - Gebhardt, Moritz Oliver A1 - Rethmeier, Michael ED - Babu, S. S. ED - Bhadeshia, H.K. ED - Cross, C.E. ED - David, S.A. ED - DebRoy, T. ED - DuPont, J.N. ED - Koseki, T. ED - Liu, S. T1 - Influence of imperfections on the fatigue performance of resistance spot welded joints N2 - In this study, the influence of two different types of weld imperfections, i.e. production-related gaps and weld cracks, on the fatigue performance was investigated for resistance spot welded TRIP steel HCT690. It was ascertained that gaps of 3 mm lead to a significant drop in fatigue life compared to gap free shear tension samples under a load ratio R of 0.1. This fact was attributed to decreased stiffness, higher transverse vibration and higher rotation () between the sheets. Furthermore, FE-simulations have shown an increase in local stresses in gapped samples. The investigation into the influence of cracks was split depending on the crack location in the weld area. Surface cracks in the electrode indentation area as well as in the HAZ were produced and analyzed. The results showed that surface cracks independent of their position have no effect on the fatigue life. The produced internal imperfections have shown only a marginal impact on the fatigue life. By using a 3D FE-simulation of crack containing samples and crack free samples the influence of such imperfections was validated by determining the local stresses in critical areas. T2 - 9th International conference on trends in welding research CY - Chicago, Illinois, USA DA - 04.06.2012 KW - Resistance spot welding KW - Gaps KW - Cracks KW - Fatigue life KW - Simulation PY - 2013 SN - 978-1-62708-998-2 SP - 650 EP - 660 PB - ASM international AN - OPUS4-29056 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habib, Abdel Karim A1 - Schalau, Bernd T1 - Numerische Simulation der Gasausbreitung N2 - Die VDI Richtlinie 3783, Blatt 2 zeigt im Vergleich mit den experimentellen Daten aus den eigene Versuchsreihen zur Schwergasausbreitung eine gute konservative Abschätzung der Konzentrationsverteilung. Die Berechnungen für die Ausbreitung dichteneutraler Gase mit Blatt 1 der Richtlinie lieferten jedoch zu niedrige Konzentrationswerte. Allgemein ist festzuhalten, dass die Anforderungen an die Datenlage zu den Randbedingungen sehr niedrig sind ebenso wie der Rechenaufwand. AUSTAL2000 hat eine wesentlich bessere Übereinstimmung mit dem Messwerten für die Ausbreitung dichteneutraler Gase gezeigt. Diese Feststellung sollte jedoch noch durch den Vergleich mit weiteren Messreihen verifiziert werden. AUSTAL2000 hat in Zusammenhang mit dem diagnostischen Windfeldmodell im Vergleich zu Blatt 1 der VDI Richtlinie 3783 den Vorteil, dass Gebäude explizit berücksichtigt werden können. Als Partikelmodell ist es außerdem in der Lage den Nahbereich der Quelle berechnen zu können. Der Rechenaufwand hierbei ist jedoch deutlich höher als bei der VDI Richtlinie 3783, während die Anforderungen an die Randbedingungen ähnlich niedrig sind. CFX hat sich als flexibles Berechnungswerkzeug erwiesen. In allen betrachteten Fällen konnte für die instationäre Berechnung eine gute Übereinstimmung mit den Messwerten nachgewiesen werden. Hierbei ist es jedoch erforderlich, eine sehr detaillierte Kenntnis über die zeitabhängige Entwicklung der Randbedingungen zu haben. Der Vorteil von CFD-Modellen liegt in der universellen Einsetzbarkeit verglichen mit den spezialisierten Modellen die auf einen sehr engen Anwendungsbereich beschränkt sind. Weiterhin liefern CFD-Modelle detaillierte Informationen über die räumlichen Phänomene. Spätestens bei der Untersuchung der Auswirkungen spezifischer Hindernisse z.B. eines neuen Gebäudes in einer Industrieanlage auf die Gasausbreitung ist CFD sicherlich die Methode der Wahl. Der Einsatz von CFD Methoden ist jedoch sehr Zeit- und Rechenaufwändig. T2 - 11. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 07.11.2013 KW - Gasausbreitung KW - Simulation PY - 2013 SN - 978-3-86011-058-4 IS - O-03 SP - 1 EP - 10 AN - OPUS4-29547 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habib, Abdel Karim A1 - Schalau, Bernd A1 - Schmidt, Dirk ED - Beyer, M. ED - Stolz, T. T1 - Simulation und experimentelle Untersuchungen der Schwergasausbreitung T2 - 13. BAM-PTB-Kolloquium zur chemischen und physikalischen Sicherheitstechnik CY - Braunschweig, Germany DA - 2013-06-18 KW - Schwergas KW - Ausbreitung KW - Simulation PY - 2013 SN - 978-3-95606-062-5 SN - 1868-5838 SP - 1 EP - 7 AN - OPUS4-29584 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habib, Abdel Karim A1 - Schalau, Bernd A1 - Schmidt, Dirk ED - Pierucci, S. ED - Klemes, J.J. ED - De Rademaeker, E. ED - Fabiano, B. ED - Buratti, S.S. T1 - Comparing different methods for calculating the gas dispersion N2 - When handling flammable and/or toxic liquids or gases, the gas dispersion following a release of substance is a scenario to be considered in the risk assessment to determine the lower flammability distance (LFD) and toxicity thresholds. In this work a comparison of different gas dispersion tools of varying complexity ranging from a simple Gaussian model over a boundary layer model (BLM) and a Lagrangian model to CFD (in this case ANSYS CFX v14) is presented. The BLM covers the special case of liquid releases with formation of a pool. It does not only solve the gas dispersion but also calculates the evaporating mass flow out of the pool. The simulation values are compared to each other and to experimental data resulting mainly from our own open air experiments covering the near field and carried out on the Test Site Technical Safety of BAM (BAM-TTS) for different release types (pool evaporation, gas release) and topologies. Other validation data were taken from literature and cover large scale experiments in the range of several 100 m. T2 - 14th International symposium on loss prevention and safety promotion in the process industries CY - Florence, Italy DA - 12.05.2013 KW - Gas dispersion KW - Simulation PY - 2013 SN - 978-88-95608-22-8 SN - 1974-9791 N1 - Serientitel: Chemical engineering transactions – Series title: Chemical engineering transactions IS - 31 SP - 1 EP - 6 PB - AIDIC, Associazione Italiana di Ingegneria Chimica CY - Milano AN - OPUS4-29587 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ahiboz, D. A1 - Andresen, Elina A1 - Manley, P. A1 - Resch-Genger, Ute A1 - Würth, Christian A1 - Becker, C. T1 - Enhanced photon upconversion using erbium-doped nanoparticles interacting with silicon metasurfaces N2 - Photon upconversion (UC) using trivalent erbium (Er+3) doped crystals is a promising concept to harness near infrared photons of the solar spectrum which cannot be directly absorbed by silicon solar cells. However, their UC efficiency at low-intensity 1 sun illumination is not relevant on device level so far. Exploiting giant near-field enhancement effects on metasurfaces is an appealing approach to enable efficient UC at low irradiance conditions. Here, we report on more than 1000-fold enhanced photon UC of NaYF4:Er+3 nanoparticles interacting with the near-fields supported by a silicon metasurface under 1550 nm excitation. T2 - 48th Photovoltaic Specialists Conference (PVSC) CY - Online meeting DA - 20.06.2021 KW - Nano KW - Nanomaterial KW - Upconversion nanoparticle KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Sensor KW - Excitation power density KW - Brightness KW - NIR KW - Mechanism KW - Modeling KW - Simulation KW - Energy transfer KW - Photonic crystal KW - Enhancement strategy PY - 2021 DO - https://doi.org/10.1109/pvsc43889.2021.9518495 SP - 1 EP - 3 PB - IEEE CY - Berlin AN - OPUS4-53786 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fedelich, Bernard A1 - Haftaoglu, Cetin A1 - Kindrachuk, Vitaliy T1 - Zur rechnerischen Bewertung der Lebensdauer von Bauteilen unter TMF mit einer Kombination von kommerziellen FE-Programmen und Anwendersoftware N2 - Die Analyse der Lebensdauer von Bauteilen unter thermomechanischer Ermüdung (TMF) erfordert ein geeignetes Stoffgesetz, welches in der Lage ist, zyklische Plastizität die Abhängigkeit der Spannungsantwort nach der Dehnrate, Kriechen und Spannungsrelaxation temperaturabhängig zu beschreiben und ein Lebensdauermodell, welches in Abhängigkeit von der örtlich aufgelösten Spannungs- und Verformungsgeschichten eine Schätzung der Anzahl der Zyklen bis zum Anriss liefern kann. T2 - DVM-Tag 2017 Bauteil verstehen CY - Berlin, Germany DA - 26.04.2017 KW - Finite Elemente Methode KW - Simulation KW - Viskoplastizität KW - Low cycle Fatigue PY - 2017 SP - 17 EP - 19 AN - OPUS4-43357 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Hongyi A1 - Hofmann-Böllinghaus, Anja ED - Makovická Osvaldová, L. ED - Hasburgh, L. E. ED - Das, O. T1 - Applying experimental determined kinetic parameters to the simulation of vegetation fire in the Fire Dynamics Simulator N2 - Although intense wildfire research has been done in the US and in Australia, it cannot be transferred directly to the situation in Europe as the local vegetation has a significant influence on the fire spread. The EU-funded project TREEADS and the so-called German pilot within the project are concentrating on wildfire in Europe. Extensive experimental research is done on local vegeta-tion in Germany and the experimental results are used to adjust the Fire Dynam-ics Simulator (FDS) to local vegetation as a fuel in the calculations. The particle model and the boundary fuel model are developed for the simulation of forest fires. Both models require the kinetic input for the dehydration, pyrolysis, and char oxidation process. This three-step simplified model describes the basic fuel combustion kinetic. Most published simulations use the default kinetic input of pine needles from FDS user manual. To adjust the simulation to local vegetation, the corresponding kinetic parame-ters have been experimental investigated. Samples of pine needles, moss and other falling leaves were collected, air dried and grinded into powder. The TG analysis of all these samples were done under different heating rate of 5, 10 and 20K/min. The activation energy and the corresponding pre-exponential factor were calcu-lated. The results show that fire spread depends significantly on the vegetation and comparison with small scale experiments show good agreement using the new kinetic parameters. The new model is applied to a larger scenario and will be compared to the results of large-scale experiments for further validation of the model. T2 - Wood and Fire Safety 2024 CY - Štrbské Pleso, Slovakia DA - 12.05.2024 KW - Forest KW - Simulation KW - FDS KW - Vegetation fire KW - Fire Dynamics Simulator KW - Kinetic parameters PY - 2024 SN - 978-3-031-59177-8 DO - https://doi.org/10.1007/978-3-031-59177-8_45 SP - 389 EP - 396 PB - Springer CY - Cham AN - OPUS4-60252 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Hongyi A1 - Hofmann-Böllinghaus, Anja T1 - TREEADS - Experimente und numerische Simulation zur Brandausbreitung von Vegetationsbränden N2 - Um die Ausbreitungsmechanismen von Vegetationsbränden und besonders bei Bodenbränden besser zu verstehen, wurden die Einflussfaktoren auf die Brandausbreitung näher untersucht. Da die Brandausbreitung auch in starkem Maße von der lokalen Vegetation abhängt, war eine Charakterisierung der lokalen Vegetation und der Bodenverhältnisse wichtig. Die Wetterverhältnisse spielen einerseits im Vorfeld des Brandes durch längere Dürreperioden als auch während des Brandes, z.B. durch den Windeinfluss, zusätzlich eine große Rolle. Durch die numerische Simulation kann eine größere Variation der Einflussgrößen abgebildet werden als durch die zeitlich und finanziell begrenzten experimentellen Möglichkeiten. Für die Berechnungen wird der Fire Dynamic Simulators (FDS) mit dem Paket WFDS verwendet. Dadurch kann mit einem vereinfachten 3-Phasen-Reaktionskinetikmodell, bestehend aus Dehydrierung, Pyrolyse, Kohleoxidation, die Ausbreitung von Vegetationsbränden verschiedener Waldbodenarten untersucht werden. Es wurden dazu 6 typische Pflanzenarten und Bodenproben aus Kiefern-, Buchen und Eichenbeständen ausgewählt. Die gesammelten Waldbodenproben wurden alle hinsichtlich des Wassergehalts, des organischen Gehalts, der Packungsdichte, der Dichte und der statistisch ermittelten Pflanzenartenverteilung charakterisiert. Das kinetische Abbrandverhalten wurde durch Thermogravimetrische Analyse (TGA) untersucht. Alle diese Daten wurden als Eingabeparameter für die Simulation verwendet. Die numerischen Simulationen werden mit Experimenten im kleinen, mittleren und Real-Maßstab validiert. T2 - 70. Jahresfachtagung der Vereinigung zur Förderung des Deutschen Brandschutzes CY - Magdeburg, Germany DA - 06.05.2024 KW - Waldbrand KW - Simulation KW - FDS PY - 2024 SN - 978-3-936050-38-7 SP - 321 EP - 336 PB - VdS CY - Köln ET - 2 AN - OPUS4-60258 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geoerg, Paul A1 - Hofmann-Böllinghaus, Anja A1 - Krause, U. T1 - Comparative study of evacuation dynamics using a lecturer room N2 - Computer simulation tools were used to evaluate pedestrian movement. This study compares the reliability of three simulation tools and the calculation method by Predtetschenski und Milinski with a controlled evacuation exercise of a lecturer room. The comparison shows that each simulation tool used underestimate the total evacuation time and that an indicator for a low level of fitness does not necessarily lead to a long evacuation time. Results revealed that calibration of simulation tools is required to model heterogeneous population properly. Therefore, further experiments with a realistic, heterogeneous composition of participants have to be made. T2 - 6th international symposium on human behaviour in fire 2015 CY - Cambridge, UK DA - 28.09.2015 KW - Pedestrian KW - Simulation KW - Evacuation KW - Heterogeneous groups PY - 2015 SN - 978-0-9933933-0-3 SP - 667 EP - 670 AN - OPUS4-34549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geoerg, Paul A1 - Rost, M. A1 - Krause, U. A1 - Hofmann-Böllinghaus, Anja T1 - Vergleichende Untersuchung zur Personensicherheit am Beispiel eines Seminarraumes N2 - Um den Anforderungen der Bauordnung an den Brandschutz für Gebäude gerecht zu werden, sind bauliche Anlagen so zu errichten und zu betreiben, dass der Entstehung eines Brandes und der Ausbreitung von Feuer und Rauch vorgebeugt, die Rettung von Menschen und Tieren sowie wirksame Löscharbeiten ermöglicht werden. Hierbei besteht, einer steigenden Komplexität sowie einem differenzierten Nutzungskonzept öffentlicher Gebäude geschuldet, häufig die Notwendigkeit von normativen Vorgaben abzuweichen und dennoch ein gleichwertiges Sicherheitsniveau nachzuweisen. Es werden Personensimulationsmodelle eingesetzt, die einerseits das Vorhandensein eines Schutzzielniveaus durch die Abbildungen von Personenbewegungen nachweisen können und andererseits durch Parametervariation eine szenarienabhängige Betrachtung ermöglichen. Der vorliegende Beitrag vergleicht die Ergebnisse einer kleinskaligen Evakuierungsübung mit drei mikroskopischen Personensimulationsmodellen und geht der Frage nach der Aussagekraft dieser Bewertungsmethode nach. Es zeigt sich, dass die alleinige Betrachtung absoluter Entleerungszeiten keine zuverlässige Beurteilungsgrundlage für das komplexe Schutzziel Personensicherheit darstellt. T2 - 4. Magdeburger Brand- und Explosionsschutztag / 3. vfdb-Workshop Brandschutzforschung CY - Magdeburg, Germany DA - 26.03.2015 KW - Evakuierung KW - Routenwahl KW - Fußgänger KW - Sicherheit KW - Simulation PY - 2015 SN - 978-3-00-048960-0 SP - 1 EP - 13 AN - OPUS4-33123 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vasilic, Ksenija A1 - Kühne, Hans-Carsten A1 - Schmidt, Wolfram A1 - Roussel, N. T1 - Numerical simulations of scc casting: parameter determination N2 - The paper addresses numerical modelling of fresh self-compacting concrete. In the previous studies, a numerical tool for casting prediction is built based on the assumption that fresh concrete behaves as a yield-stress fluid and treating zones with rebars as porous media. The present contribution discusses the determination of material parameters, which are required as an input for numerical simulations of casting processes. T2 - International RILEM Conference on Materials, Systems and Structures in Civil Engineering 2016, Segment on Fresh Concrete CY - Lyngby, Denmark DA - 22.08.2016 KW - Fresh concrete KW - Simulation KW - CFD KW - Rheology PY - 2016 SN - 978-2-35158-184-1 SP - 163 EP - 172 PB - RILEM Publications S.A.R.L. CY - Paris, France AN - OPUS4-37446 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Torge, Manfred ED - Brion, I. ED - Alloteau, F. ED - Lehuede, P. ED - Majerus, O. ED - Caurant, D. T1 - The effect of particle deposition and climate on glass degradation N2 - Medieval stained-glass windows are protected by an outside gazing system in many churches.The interspace between the original and the protective glass is ventilated with air from the indoor or exterior environment, where dust and particles can move.Cascade impactor measurements and SEM/EDX analyses of sampled dust were carried to determine the dust composition. The effect of particles on model glass samples was investigated in climate chambers under accelerated weathering conditions. The results from in situ measurements and laboratory tests were combined to evaluate the potential effect of particulate matter on historic stained-glass Windows. T2 - International Symposium on Glass Degradation in Atmospheric Conditions CY - Paris, France DA - 15.11.2017 KW - Medieval-stained glass KW - Protective glazing KW - Cascade impector KW - Simulation PY - 2019 SN - 9782705697945 SP - 223 EP - 224 PB - hermann CY - Paris AN - OPUS4-49023 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Skrotzki, Birgit A1 - Uckert, Danilo A1 - Matzak, Kathrin A1 - Kühn, Hans-Joachim A1 - Rehmer, Birgit A1 - Peter, Frauke A1 - Fedelich, Bernard A1 - Falkenberg, Rainer A1 - Haftaoglu, Cetin A1 - Kindrachuk, Vitaliy T1 - Erweiterung bestehender Werkstoff- und Rechenmodelle zur Lebensdauervorhersage für Abgasturbolader-Heißteile unter thermomechanischer Ermüdungsbeanspruchung N2 - In diesem Forschungsvorhaben erfolgte eine Überprüfung der Übertragbarkeit der Werkstoff- und Rechenmodelle für die Lebensdauervorhersage von ATL-Heißteilen unter TMF-Beanspruchung auf eine andere Werkstoffklasse, d. h. auf eine austenitische Gusseisenlegierung mit Kugelgraphit. Dafür wurde die Legierung EN-GJSA-XNiSiCr35-5-2 (Ni-Resist D-5S) ausgewählt. Zunächst wurde für diesen Werkstoff eine experimentelle Datenbasis geschaffen, da diese vor Beginn des Vorhabens nicht ausreichend war. Dazu wurden Zug-, Kriech-, LCF- und TMF-Versuche durchgeführt, die der Kalibrierung der Modelle dienten. Unter TMF-Belastung zeigte der untersuchte Werkstoff ein stark abweichendes Verhalten von den im vorangegangenen Vorhaben untersuchten ferritischen SiMo-Legierungen: Der Werkstoff Ni-Resist zeigte insgesamt eine vergleichbare Festigkeit unter OP- und IP-Bedingungen, während die ferritischen Legierungen unter IP-Beanspruchung eine deutlich höhere Festigkeit aufweisen. Mit zunehmenden Temperaturen und Haltezeiten unter Zugspannungen wurden dagegen beim Werkstoff Ni-Resist Hinweise auf Kriechschädigung gefunden, die schädigungsrelevant sind. Auch dies ist ein deutlicher Unterschied zu den SiMo-Legierungen. Das Spannungs-Verformungs-Verhalten in den LCF- und TMF-Versuchen wird durch das Modell auch für den neuen Werkstoff überwiegend gut beschrieben. Das Gleiche gilt für die Lebensdauervorhersage, die mit Ausnahme der Prüftemperatur 900 °C innerhalb eines Fak-tors zwei liegt. Eine Verifikation des Modells erfolgte mit Hilfe eines Bauteilversuchs an einem Abgassammler, der abwechselnd mit heißem und kaltem Gas durchströmt wurde. Ziel der Bauteilsimulation war insbesondere die Vorhersage der Rissbildungsorte. Eine Vorhersage der exakten Lebensdauer wurde nicht erwartet, da das Bauteil mit einer Gusshaut behaftet war, während die für die Kalibrierung des Lebensdauermodells verwendeten Versuche an bearbeiteten, glatten Proben ohne Gusshaut durchgeführt wurden. Die überwiegende Anzahl der experimentell ermittelten Rissorte wurden vorhergesagt. Schließlich war ein wesentliches Ziel des Vorhabens, den Einfluss von HCF-Schwingungen auf die TMF-Lebensdauer vertieft experimentell zu untersuchen und das bereits bestehende Lebensdauermodell auf HCF-Überlagerung zu erweitern. Dazu wurde zunächst die Daten-basis aus dem Vorgängervorhaben am Bespiel von SiMo 4.05 deutlich ausgebaut, um die verschiedenen Einflussparameter zu erfassen. Es wurde ein Ansatz entwickelt, in dem die Lebensdauerminderung durch die überlagerten HCF-Schwingungen abgebildet wird. Dabei wird davon ausgegangen, dass ab einer bestimmten Risstiefe die Überlagerung der HCF-Schwingungen die Rissausbreitung stark beschleunigt. Der Zeitpunkt, wann diese Beschleunigung eintritt, wird als maßgeblich für die Lebensdauerminderung angesehen. Mit diesem Ansatz lassen sich die Lebensdauern für beide Werkstoffe in guter Übereinstimmung mit dem Experiment vorhersagen. T2 - Informationstagung Turbomaschinen, Frühjahr 2016 CY - Bad Neuenahr, Germany DA - 13.04.2016 KW - Ermüdung KW - LCF KW - Modellierung KW - Schädigung KW - Simulation KW - TMF PY - 2016 VL - Heft R575 SP - 1 EP - 35 AN - OPUS4-35823 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winkelmann, Aimo A1 - Nolze, Gert A1 - Voss, M. A1 - Salvat-Pujol, F. A1 - Werner, W. S. M. T1 - Physics-based simulation models for EBSD: advances and challenges N2 - EBSD has evolved into an effective tool for microstructure investigations in the scanning electron microscope. The purpose of this contribution is to give an overview of various simulation approaches for EBSD Kikuchi patterns and to discuss some of the underlying physical mechanisms. T2 - EMAS 2015 - 14th European Workshop on MODERN DEVELOPMENTS AND APPLICATIONS IN MICROBEAM ANALYSIS CY - Portoroz, Slovenia DA - 03.05.2015 KW - Electron backscatter diffraction KW - Simulation KW - Dynamical theory KW - Kinematic theory PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-377469 DO - https://doi.org/10.1088/1757-899X/109/1/012018 VL - 109 SP - 012018-1 EP - 012018-13 AN - OPUS4-37746 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaenisch, Gerd-Rüdiger A1 - Kolkoori, Sanjeevareddy A1 - Deresch, Andreas T1 - Influence of scattered radiation on the efficiency of dual high-energy X-Ray imaging for material characterization N2 - In this contribution, we discuss the influence of scattered radiation on materials’ effective attenuation coefficients at higher X-ray energies. The selected X-ray spectra for the dual-energy experiments correspond to 3 MV and 7.5 MV acceleration potential of the used betatron. Experiments were performed on a test phantom containing step wedges of different low- and high-Z materials. We evaluated the ratio between low- and high-energy X-ray attenuation coefficients quantitatively based on simulated poly-energetic high-energy X-ray source spectra and the detector sensitivity using the “analytical Radiographic Testing inspection simulation tool” (aRTist) developed at BAM. Furthermore, the influence of scattered radiation is evaluated using an efficient Monte-Carlo simulation. The simulation results are compared quantitatively with experimental investigations. Finally, important applications of the proposed technique in the context of aviation security are discussed. T2 - 19th World Conference on Nondestructive Testing CY - Munich, Germany DA - 13.06.2016 KW - Monte Carlo methods KW - Dual-energy imaging KW - Simulation KW - Experiments PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-365925 SN - 978-3-940283-78-8 VL - 158 SP - 1 EP - 10 PB - DGZfP CY - Berlin, Germany AN - OPUS4-36592 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan A1 - Zencker, Uwe A1 - Völzke, Holger A1 - Wille, Frank A1 - Musolff, André ED - Topping, B.H.V. T1 - Validation of numerical simulation models for transport and storage casks using drop test results N2 - The safety assessment of new designs for transport and storage casks for radioactive materials is a challenging task accomplished using different methods such as prototype tests, model tests, calculations and analogy reflections. At BAM (Federal Institute for Materials Research and Testing), the test procedures for the mechanical IAEA (International Atomic Energy Agency) test conditions often start with preliminary finite element (FE) calculations mostly with a small-scale cask model for verification of the proposed test cask instrumentation and test plan. On that basis the extensive test cask instrumentation is applied and checked. After that, a series of drop tests consisting of different test sequences is performed. Following the drop tests, numerical post-analyses are carried out. These analyses offer the possibility of a detailed calculation and assessment of stresses and strains in the entire test cask construction. The calculation results have to be carefully compared with the measurement data over the impact history to find out all relevant parameters for a realistic simulation of the impact scenario. The desired ideal boundary test conditions often cannot be met exactly during the drop tests. Therefore, the numerical post-analyses are carried out by using the real boundary conditions of the drop tests. The objective is to find a validated model, where the results of the numerical simulations satisfactorily meet the experimental results. Under test conditions according to the IAEA transport regulations, casks are usually equipped with impact limiters and dropped onto a so-called unyielding target. In general, it is difficult to verify a complex FE model by using results from only one drop test because of the complex impact process and the complex structure of such packages. After each drop test, numerical post-analyses should be carried out. Only if all drop tests were simulated successfully by using the same FE model under different test conditions, it is possible to obtain a validated numerical model for further investigations. In this case the results of the numerical simulations meet satisfactorily the experimental results. In this paper a study is presented, where the influence of different components on the cask loading is investigated systematically. T2 - 11th International conference on computational structures technology CY - Dubrovnik, Croatia DA - 04.09.2012 KW - Impact KW - Simulation KW - Cask KW - Dop test KW - Finite element model KW - Validation KW - Dynamics KW - Transport and storage cask PY - 2012 DO - https://doi.org/10.4203/ccp.99.273 SN - 1759-3433 IS - Paper 273 SP - 1 EP - 12 PB - Civil Comp Press AN - OPUS4-26537 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaenisch, Gerd-Rüdiger A1 - Kolkoori, Sanjeevareddy A1 - Bellon, Carsten T1 - Quantitative simulation of back scatter X-ray imaging and comparison to experiments N2 - X-ray backscatter imaging is a well established NDT technique to inspect complex objects using only a single-sided access. In difference to conventional transmission X-ray radiography, the X-ray backscatter imaging utilizes the scattered radiation caused by the Compton scattering effect. In order to achieve high backscatter intensities from a test object, it is necessary to optimize the backscatter system parameters namely the angle between source and slit camera, the slit collimator system, the shielding between source and scatter camera, and the type of detector. In addition, the scatter phenomena in to the investigated object need to be understood. In this contribution, we present a Monte Carlo model McRay which considers all relevant single and multiple interactions of photons and electrons. This model can be used to simulate back scatter techniques. It allows not only calculating the scatter image for a given experimental setup but also registering the spectrum of the detected scattered photons. Both aspects are important to understand the imaging process, to interpret the results, and to optimize the backscatter camera investigated here. Additionally experimental results will be presented and compared with simulations. T2 - 19th World Conference on Nondestructive Testing CY - Munich, Germany DA - 13.06.2016 KW - Radiology KW - Back-scatter techniques KW - Simulation KW - Monte Carlo methods KW - Measurements PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-365897 SN - 978-3-940283-78-8 VL - 158 SP - 1 EP - 11 PB - Deutsche Gesellschaft für zerstörungsfreie Prüfung (DGZfP) CY - Berlin, Germany AN - OPUS4-36589 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten A1 - Jaenisch, Gerd-Rüdiger A1 - Deresch, Andreas T1 - Combining analytical and Monte Carlo modelling for industrial radiology N2 - Modelling becomes more and more important in modern NDE. It is increasingly used to optimize techniques for complex applications, to support the preparation of written procedures, and for education purposes. To describe the complete chain of RT, the model includes simulating all necessary properties of X- or Gamma-ray sources, the interaction of photons with material with special attention to scattered radiation, the detection process, and the complete geometrical RT setup handling arbitrary parts or constructions. Depending on the given inspection problem and the influencing factors that should be addressed by the simulation, an appropriate physical model has to be chosen to describe the underlying interaction mechanisms. The simulator aRTist combines analytical and Monte Carlo methods to efficiently model the radiation transport such that transmission as well as scatter techniques can be modelled. In this contribution we Focus on Monte Carlo Simulation of scatter contribution within aRTist. Examples for RT/tomographic applications and back-scatter techniques are presented to demonstrate the usability of the presented simulation tool for a broad range of radiological applications. T2 - 19th Wolrd Conference on Nondestructive Testing CY - Munich, Germany DA - 13.06.2016 KW - Radiography KW - Computed tomography KW - Simulation KW - Monte Carlo methods PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-365856 SN - 978-3-940283-78-8 VL - 158 SP - 1 EP - 9 PB - Deutsche Gesellschaft für zerstörungsfreie Prüfung (DGZfP) CY - Berlin, Germany AN - OPUS4-36585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja A1 - Wachtendorf, Volker ED - Ziegahn, K.-F. T1 - Lebensdauerabschätzungen für Polypropylen durch Dosis-Wirkungsfunktionen bezüglich Bestrahlungsstärke und Temperatur (ViPQuali-Projekt) N2 - Für Polypropylen unterschiedlicher Stabilisierung wurden in künstlichen Bestrahlungstests sowohl die spektrale Empfindlichkeit als auch die Temperaturabhängigkeit der Rissbildung quantitativ ermittelt. Dafür wurde die Dauer bis zur Rissbildung sowohl bei spektraler Bestrahlung als auch bei Bestrahlung in einem UV-Leuchtstofflampengerät bei verschiedenen Temperaturen bestimmt. Die Temperaturabhängigkeit konnte als Arrhenius-Abhängigkeit beschrieben werden; das Wirkungsspektrum wurde an eine Stufenfunktion angepasst. Anschließend wurde auch noch der Einfluss des Stabilisatorgehalts als Potenzfit parametrisiert. Die Einzelabhängigkeiten wurden zu einer Gesamtfunktion der Wirkungen in Abhängigkeit der Dosis zusammengesetzt, die es ermöglicht die Wirkungen unterschiedlicher Dosiskombinationen abzuschätzen. Zur Validierung der Dosis-Wirkungsfunktionen wurden Freibewitterungsergebnisse aus Phoenix/Arizona herangezogen. Mit der Dosis, die sich aus den Wetterdaten dieser Freibewitterung ergibt, wurden anhand der Dosis-Wirkungs-Funktionen die jeweiligen Lebensdauern errechnet und mit dem experimentell bestimmten Versagen in der Freibewitterung verglichen. Die Arbeiten erfolgten im Rahmen des ViPQuali-Projektes mit dem Ziel der Bestimmung der Materialkenngrößen. T2 - 40. Jahrestagung der GUS 2011 - Umwelteinflüsse erfassen, simulieren, bewerten CY - Stutensee-Blankenloch/Karlsruhe, Germany DA - 30.03.2011 KW - Bewitterung KW - UV KW - Lebensdauer KW - Simulation KW - Polypropylen PY - 2011 SN - 978-3-9813136-1-1 IS - V17 SP - 227 EP - 237 PB - DWS Werbeagentur und Verlag GmbH CY - Karlsruhe AN - OPUS4-23474 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gravenkamp, Hauke A1 - Song, C. A1 - Prager, Jens T1 - Numerical simulation of ultrasonic guided waves using the scaled boundary finite element method N2 - The formulation of the Scaled Boundary Finite Element Method is applied for the computation of dispersion properties of ultrasonic guided waves. The cross-section of the waveguide is discretized in the Finite Element sense, while the direction of propagation is described analytically. A standard eigenvalue problem is derived to compute the wave numbers of propagating modes. This paper focuses on cylindrical waveguides, where only a straight line has to be discretized. Higher-order elements are utilized for the discretization. As examples, dispersion curves are computed for a homogeneous pipe and a layered cylinder. T2 - 2012 IEEE International Ultrasonics Symposium (IUS) CY - Dresden, Germany DA - 07.10.2012 KW - Guided waves KW - Simulation KW - Dispersion KW - Scaled boundary finite element method PY - 2012 SN - 978-1-4673-4562-0 DO - https://doi.org/10.1109/ULTSYM.2012.0673 SN - 1948-5719 SP - 2686 EP - 2689 AN - OPUS4-29665 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -