@misc{KriegelSchmidtSchmidt, author = {Kriegel-Schmidt, Katharina and Schmidt, Klaus}, title = {Kultur als Blickwinkel in interkulturell orientierten Lernsettings : didaktische und theoretische Reflexionen am Beispiel einer Ausbildung in Interkultureller Mediation}, series = {Interculture Journal}, volume = {13}, journal = {Interculture Journal}, number = {22}, issn = {2196-9485}, pages = {27 -- 44}, language = {de} } @techreport{BeckerClareDietrichetal., author = {Becker, J{\"o}rg and Clare, Lee and Dietrich, Oliver and K{\"o}ksal-Schmidt, {\c{C}}iğdem and Merbach, Anja and Notroff, Jens and Pant, Smriti and Peters, Joris and P{\"o}llath, Nadja and Schmidt, Klaus}, title = {G{\"o}bekli Tepe Newsletter 2014}, publisher = {German Archaeological Institute, Press Office}, address = {Berlin}, pages = {27}, language = {en} } @incollection{KriegelSchmidtSchmidt, author = {Kriegel-Schmidt, Katharina and Schmidt, Klaus}, title = {Programmatische Achsen einer kulturwissenschaftlichen Erforschung von Mediation}, series = {Mediation als Wissenschaftszweig. Im Spannungsfeld von Fachexpertise und Interdisziplinarit{\"a}t}, booktitle = {Mediation als Wissenschaftszweig. Im Spannungsfeld von Fachexpertise und Interdisziplinarit{\"a}t}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-658-18256-4}, pages = {57 -- 70}, language = {de} } @incollection{RheidtSchmidt, author = {Rheidt, Klaus and Schmidt, Leo}, title = {Vom Denkmal zur Rekonstruktion}, series = {Von der Reproduktion zur Rekonstruktion - Umgang mit Antike(n) II : Summerschool vom 16. - 19. Juni 2014 in T{\"u}bingen}, booktitle = {Von der Reproduktion zur Rekonstruktion - Umgang mit Antike(n) II : Summerschool vom 16. - 19. Juni 2014 in T{\"u}bingen}, editor = {Zimmer, Kathrin Barbara}, publisher = {VML, Verlag Marie Leidorf GmbH}, address = {Rahden/Westf.}, isbn = {978-3-89646-912-0}, pages = {9 -- 21}, language = {de} } @misc{XieStarickMosgowetal., author = {Xie, Tianxiao and Starick, Tommy and Mosgow, Anatol and Berg, Heinz Peter and H{\"o}schler, Klaus and Schmidt, Heiko}, title = {Thermofluiddynamic pre-design of a primary surface heat exchanger under the influence of heat radiation using 1D/3D coupled simulation method}, series = {NAFEMS World Congress 2021, online, 25-29. Oktober 2021}, journal = {NAFEMS World Congress 2021, online, 25-29. Oktober 2021}, pages = {25}, abstract = {Within the Framework of the "TurboFuelCell (TFC)" a highly integrated and compact energy conversion system based on Micro Gas Turbine Solid Oxide Fuel Cell (MGT-SOFC) hybrid process is being developed by the team at BTU-Cottbus Senftenberg. This work focuses on the extension of the pre-design process of a primary surface heat exchanger (PSHX), which is a key component for the coupling between MGT and SOFC, using an 1D/3D hybrid simulation method for the understanding of its behaviour under the influence of heat radiation. In a MGT-SOFC hybrid process the high temperature heat exchanger plays an important role in preheating the fresh air to a minimum operation temperature necessary for SOFC. Due to the special location of this PSHX in the TFC, it is constantly exposed to heat radiation from the SOFC module, which requires additional consideration of its influence for better model accuracy. A first design, which is later extended through an 1D Flow network model, based on 𝜖 - 𝑁𝑇𝑈 method is presented. A complete 3D-CFD simulation with consideration of heat radiation is initially employed for the whole flow process to examine the first design. However, this approach proves to be highly computationally expensive due to the large dimensional difference between the plenum for cathode exhaust air and the fine channels in the PSHX. To reduce the computational effort, the flow and heat transfer in the PSHX is modelled by 1D elements. The flow in the plenum is simulated by 3D-CFD, which better accounts for convection and thermal radiation. A comparison between 3D-CFD and 1D/3D hybrid model is performed. A significant reduction of simulation time and computing resources can be achieved for well calibrated hybrid model without compromising on accuracy. In the talk, the effect of insulation layer thickness variations on the heat transfer on the plenum side due to heat radiation and their influence on the heat exchanger efficiency are discussed. Consequently, design improvements are realized based on the previous findings. Finally, the 1D/3D hybrid simulation method is evaluated and prepared for the general applications in thermal management of machines based on coupled MGT-SOFC process.}, language = {en} } @techreport{SchmidtDonathWelsetal., author = {Schmidt, Peer and Donath, Ines and Wels, Martin and Pinnau, Sebastian and Grau Turuelo, Constantino and Breitkopf, Cornelia and Hack, Klaus and Baben, Moritz to and Reis, Bruno and M{\"u}ller, Michael and Sergeev, Dmitry and Qi, Jia}, title = {PCM Screening - Evaluierung eutektischer Gemische f{\"u}r den Einsatz als PCM: thermodynamische Modellierung und experimentelle Methoden : Energie Speicher: PCM-Screening : Schlussbericht}, publisher = {TIB - Leibniz-Informationszentrum Technik und Naturwissenschaften}, address = {Hannover}, doi = {10.2314/KXP:177643451X}, pages = {163}, abstract = {Ein wichtiges Ziel der Bundesregierung ist der Ausbau des Anteils erneuerbarer Energien an der gesamten Stromerzeugung. Die Entwicklung optimierter W{\"a}rme- und K{\"a}ltespeicher stellt einen wichtigen Baustein bei der Erreichung dieser Zielstellung dar. Elektrisch betriebene W{\"a}rmepumpen und Kompressionsk{\"a}ltemaschinen sowie dezentrale Klein-BHKW bieten in Verbindung mit entsprechend dimensionierten, thermischen Speichern ein großes Potential zum Lastmanagement in Smart Grids und somit zur Netzintegration von Strom aus erneuerbaren Energien. Die im Projekt entwickelte Methodik zur Suche nach neuen Latentspeichermedien kann f{\"u}r ein breites Anwendungsfeld von Heiz- und K{\"u}hlanwendungen in Geb{\"a}uden bis hin zur Kraftwerkstechnik eingesetzt werden. Innerhalb der F{\"o}rdermaßnahme „Anwendungsorientierte Forschung und Entwicklung zur nichtnuklearen Energieforschung" im 6. Energieforschungsprogramm der Bundesregierung wurde durch die Projektarbeiten das Schwerpunktthema Energiespeicher (3.8) adressiert, wobei der Aspekt der Entwicklung neuer Materialien mit reduzierten Kosten f{\"u}r einen wirtschaftlichen Betrieb im Vordergrund stand. Speziell wurden dabei die Unterpunkte 3.8.4 Thermische Speicher zur Weiterentwicklung, Optimierung und Erprobung von PCM sowie 3.8.5 {\"U}bergeordnete Themen mit Modellen und Simulationswerkzeugen f{\"u}r die Auswahl und Bewertung neuer Speichermaterialien adressiert. Die Projektergebnisse besitzen aber auch Ber{\"u}hrungspunkte mit den Schwerpunkten 3.12 Energieeffizienz in Industrie, Gewerbe, Handel und Dienstleistungen sowie 3.4 Solarthermische Kraftwerke, da mit der entwickelten Screening-Methode f{\"u}r diese Anwendungsf{\"a}lle neue W{\"a}rmespeichermaterialien auf der Basis wasserfreier Salze mit h{\"o}heren Prozesstemperaturen gefunden werden k{\"o}nnen. Durch den Einsatz von Methoden zur Modellierung und Simulation von Prozessen erfolgt gleichermaßen die Umsetzung einer energie- und ressourcenschonenden Forschungst{\"a}tigkeit. Das im Projekt entwickelte Vorgehen hilft dabei, einen {\"a}ußerst sparsamen Einsatz von Chemikalien, eine niedrige Belastung der Umwelt durch verringerten Entsorgungsaufwand der verbrauchten Stoffe sowie einen deutlich geringeren Aufwand und Energieeinsatz f{\"u}r die Messtechnik zu erm{\"o}glichen. Damit wurde zugleich das Schwerpunktthema 3.8.5 Modelle und Simulationswerkzeuge f{\"u}r die Auswahl und Bewertung neuer Speichermaterialien angesprochen.}, language = {de} } @misc{FlorianSchrickerZenzetal., author = {Florian, Tobias and Schricker, Klaus and Zenz, Constantin and Otto, Andreas and Schmidt, Leander and Diegel, Christian and Friedmann, Hannes and Seibold, Marc and Hellwig, Peter and Fr{\"o}hlich, Fabian and Nagel, Falk and Kallage, Peter and Buttazzoni, Michele and Rack, Alexander and Requardt, Herwig and Chen, Yunhui and Bergmann, Jean Pierre}, title = {Combining in situ synchrotron X-ray imaging and multiphysics simulation to reveal pore formation dynamics in laser welding of copper}, series = {International Journal of Machine Tools and Manufacture}, volume = {204}, journal = {International Journal of Machine Tools and Manufacture}, publisher = {Elsevier BV}, issn = {0890-6955}, doi = {10.1016/j.ijmachtools.2024.104224}, pages = {1 -- 22}, abstract = {Laser beam welding has emerged as a powerful tool for manufacturing copper components in electrical vehicles, electronic devices or energy storage, owing to its rapid processing capabilities. Nonetheless, the material's high thermal conductivity and low absorption of infrared light can introduce process instabilities, resulting in defects such as pores. This study employs a hybrid approach that combines in situ synchrotron X-ray imaging with compressible multiphysics process simulation to elucidate pore-forming mechanisms during laser beam welding of copper. High-speed synchrotron X-ray imaging with an acquisition rate of 20,000 images/second facilitates the identification of relevant process regimes concerning pore formation during laser beam welding of copper with a wavelength of 1070 nm. Furthermore, in situ observations with high temporal and spatial resolution present a unique database for extensive validation of a multi-physics process simulation based on welding processes using different concentric intensity distributions. These validated simulation results enable thorough comprehension of process-related pore formation based on the interaction between keyhole, melt pool and resulting flow field. The findings show that pore formation is driven by four different mechanisms: bulging, spiking, upwelling waves at the keyhole rear wall and melt pool ejections. The synergy of high- speed synchrotron X-ray imaging and multi-physics modeling provides a fundamental understanding of the chronological sequence of events leading to process-related pore formation during laser beam welding of copper.}, language = {en} } @misc{WaltherSchmidtRaethetal., author = {Walther, Dominik and Schmidt, Leander and R{\"a}th, Timo and Schricker, Klaus and Bergmann, Jean Pierre and Sattler, Kai-Uwe and M{\"a}der, Patrick}, title = {Deep learning-driven active sheet positioning using linear actuators in laser beam butt welding of thin steel sheets}, series = {Journal of advanced joining processes}, volume = {11}, journal = {Journal of advanced joining processes}, publisher = {Elsevier BV}, address = {Amsterdam}, issn = {2666-3309}, doi = {10.1016/j.jajp.2025.100303}, pages = {1 -- 12}, abstract = {Welding thin steel sheets in industrial applications is difficult because joint gaps occur during the process, which can lead to weld interruptions. Such welds are considered a reject and in order to avoid the weld to interrupt it is crucial to hinder the formation of joint gaps. Especially laser beam welding is affected by the emergence of gaps. Due to the narrow laser spot, product quality is highly dependent on the alignment and positioning of the sheets. This is typically done by clamping devices, which hold the workpieces in place. However, these clamps are suited for a specific workpiece geometry and require manual redesign every time the process changes. Adaptive clamping devices instead are designed to realize a time-dependent workpiece adjustment. Modeling the joint gap behavior to realize a controller for adaptive clamps can be difficult as the influence of heating, melting, and cooling on the joint gap formation is unknown and varies due to temperature dependent physical properties. Instead, the control parameters and actions can be derived using data-driven methods. In this paper, we present a novel data-driven approach how deep learning can be utilized to manipulate the sheet position during the weld with two actuators that apply force. A temporal convolution neural network (TCN) analyzes the change of the joint gap and predicts the required force to adapt the workpiece position. The developed method has been integrated into the welding process and improves the length of the average weld seam by 39.5\% compared to welds without an active adjustment and 1.4\% to welds that have been adapted with a constant force.}, language = {en} } @misc{WaltherSchmidtSchrickeretal., author = {Walther, Dominik and Schmidt, Leander and Schricker, Klaus and Junger, Christina and Bergmann, Jean Pierre and Notni, Gunther and M{\"a}der, Patrick}, title = {Dataset for weld seam analysis and discontinuity prediction in laser beam welding scenarios}, series = {Data in brief}, volume = {59}, journal = {Data in brief}, publisher = {Elsevier BV}, address = {Amsterdam}, issn = {2352-3409}, doi = {10.1016/j.dib.2025.111381}, pages = {1 -- 8}, abstract = {Laser beam welding can produce narrow, high-quality welds in various industrial joining processes. The thermal expansion and contraction of the metal during the weld results in the displacement of the sheets. That leads to the formation of joint gaps and subsequent to a process interruption. This behavior has only been analyzed to a limited extent and causes manufacturers to rely on heavy clamping systems rather than using more flexible fixtureless approaches. Due to the time-consuming and costly nature of recording and producing erroneous weld seams, such recordings and datasets are rarely available in this area. This often limits the research towards adaptable fixtureless welding setups. Because of this, we present a multi-modal dataset consisting of 100 recorded welds that tracks the metal sheets movement. The developed setup enables the determination of boundary conditions for fixtureless welding. Two types of sensors record the welding process. First, three inductive probes are applied to record the metal sheets` movement and second, a long-wave infrared (LWIR) camera records changes in the thermal radiation field. Two different welding speeds and laser powers were used to produce a variety of welds. The dataset can be used for data-driven algorithms to predict the metal movement, analyze the thermal radiation field, or develop quality control methodologies.}, language = {en} } @misc{DiegelSchrickerSchmidtetal., author = {Diegel, Christian and Schricker, Klaus and Schmidt, Leander and Seibold, Marc and Friedmann, Hannes and Hellwig, Peter and Fr{\"o}hlich, Fabian and Nagel, Falk and Kallage, Peter and Rack, Alexander and Requardt, Herwig and Chen, Yunhui and Bergmann, Jean Pierre}, title = {In situ characterization of keyhole behavior and spatter formation in full penetration laser beam welding with local gas flow using high-speed synchrotron X-ray imaging}, series = {Optics \& laser technology}, volume = {191}, journal = {Optics \& laser technology}, publisher = {Elsevier BV}, address = {Amsterdam}, issn = {0030-3992}, doi = {10.1016/j.optlastec.2025.113367}, pages = {1 -- 17}, abstract = {Spatter formation is a major issue at welding speeds above 8 m/min for full penetration laser beam welding of high-alloyed steels. In experiments using a local gas flow directed at the keyhole rear wall, a reduction in spatter formation on the specimen top side was observed for welding of AISI 304. However, the interaction between gas flow and keyhole behavior with respect to the mechanisms and locations of spatter detachment, especially on the bottom side, is not yet fully understood. High-speed synchrotron X-ray imaging enables detailed insights into the keyhole behavior and the spatter formation to obtain a deeper understanding of the underlying mechanisms. During the reference experiments welding without shielding gas flow, the spatter detach from a melt pool swelling behind the keyhole aperture on both sides of the sheet. A gas flow with a low flow rate of 4.8 L/min reduces the spatter formation on the top side and the keyhole length due to the absence of oxygen affecting the surface tension. A swelling also forms on the keyhole front on the bottom side and small spatter detach undirected. Increasing the flow rate to 12.8 L/min elongates the keyhole, particularly on the specimen top side. The increased momentum transfer of the gas flow results in a periodic keyhole oscillation on the specimen top side. In combination with an elongated melt pool, the oscillation is directly correlated with the hump formation, caused by melt being pushed over the already solidified weld seam. In addition, spatter does not detach from the top side due to the changed melt flow and only detach from the keyhole front on the bottom side.}, language = {en} }