@inproceedings{45661, abstract = {{Effect chain modelling is a method for creating information models for impact analyses of changes in system elements. For the estimation of change propagation, dependencies between requirements must be detected. The high number of require- ment dependencies in the engineering of complex technical systems results in the need for automation. In a study, it was shown that transformer models (BERT) are suitable for the automated dependency analysis of requirements. However, there are currently deficits in the applicability of the models for different projects without an extensive and heterogeneous training database. This paper investigates how active learning can be used to train BERT models (active-BERT) in order to increase the performance of the models for classifying requi- rement dependencies of projects with heterogeneous require- ments. The results show that the performance of the models increases significantly through active learning. Through active- BERT, engineers are enabled to model effect chains efficiently and to handle requirement changes effectively.}}, author = {{Gräßler, Iris and Preuß, Daniel}}, booktitle = {{Stuttgarter Symposium für Produktentwicklung SSP 2023}}, editor = {{Hölzle, Katharina and Kreimeyer, Matthias and Roth, Daniel and Maier, Thomas and Riedel, Oliver}}, issn = {{2364-4885}}, location = {{Stuttgart}}, publisher = {{Fraunhofer IAO}}, title = {{{Automatisierte Abhängigkeitsanalyse von Anforderungen zur Wirkkettenmodellierung}}}, year = {{2023}}, } @inproceedings{46502, author = {{Gräßler, Iris and Wiechel, Dominik}}, booktitle = {{2023 18th Annual System of Systems Engineering Conference (SoSe)}}, location = {{Lille}}, publisher = {{IEEE}}, title = {{{Customized impact analyses for technical engineering changes}}}, doi = {{10.1109/sose59841.2023.10178484}}, year = {{2023}}, } @article{46503, abstract = {{ Purpose The purpose of this study is to investigate the manufacturability of Fe-3Si lattice structures and the resulting mechanical properties. This study could lead to the successful processing of squirrel cage conductors (a lattice structure by design) of an induction motor by additive manufacturing in the future. Design/methodology/approach The compression behaviour of two lattice structures where struts are arranged in a face-centred cubic position and vertical edges (FCCZ), and struts are placed at body-centred cubic (BCC) positions, prepared by laser powder bed fusion (LPBF), is explored. The experimental investigations are supported by finite element method (FEM) simulations. Findings The FCCZ lattice structure presents a peak in the stress-strain curve, whereas the BCC lattice structure manifests a plateau. The vertical struts aligned along the compression direction lead to a significant increase in the load-carrying ability of FCCZ lattice structures compared to BCC lattice structures. This results in a peak in the stress-strain curve. However, the BCC lattice structure presents the bending of struts with diagonal struts carrying the major loads with struts near the faceplate receiving the least load. A high concentration of geometrically necessary dislocations (GNDs) near the grain boundaries along cell formation is observed in the microstructure. Originality/value To the best of the authors’ knowledge, this is the first study on additive manufacturing of Fe-3Si lattice structures. Currently, there are no investigations in the literature on the manufacturability and mechanical properties of Fe-3Si lattice structures. }}, author = {{Pramanik, Sudipta and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{1355-2546}}, journal = {{Rapid Prototyping Journal}}, keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering}}, number = {{6}}, pages = {{1257--1269}}, publisher = {{Emerald}}, title = {{{Experimental and finite element method investigation on the compression behaviour of FCCZ and BCC lattice structures of additively manufactured Fe-3Si samples}}}, doi = {{10.1108/rpj-06-2022-0190}}, volume = {{29}}, year = {{2023}}, } @article{46507, author = {{Pramanik, Sudipta and Milaege, Dennis and Hein, Maxwell and Andreiev, Anatolii and Schaper, Mirko and Hoyer, Kay-Peter}}, issn = {{1438-1656}}, journal = {{Advanced Engineering Materials}}, keywords = {{Condensed Matter Physics, General Materials Science}}, number = {{14}}, publisher = {{Wiley}}, title = {{{An Experimental and Computational Modeling Study on Additively Manufactured Micro‐Architectured Ti–24Nb–4Zr–8Sn Hollow‐Strut Lattice Structures}}}, doi = {{10.1002/adem.202201850}}, volume = {{25}}, year = {{2023}}, } @unpublished{46504, author = {{Andreiev, Anatolii and Hoyer, Kay-Peter and Hengsbach, Florian and Haase, Michael and Schaper, Mirko}}, publisher = {{Elsevier BV}}, title = {{{Powder Bed Fusion of Soft-Magnetic Iron-Silicon-Based Alloys: Advantages and Challenges}}}, doi = {{10.2139/ssrn.4369485}}, year = {{2023}}, } @inproceedings{42459, author = {{Ostermann, Moritz and Behm, Jonathan and Marten, Thorsten and Tröster, Thomas}}, booktitle = {{WerkstoffPlus Auto 13. Fachtagung für neue Fahrzeug- und Werkstoffkonzepte}}, location = {{Stuttgart}}, title = {{{NeMo.bil - Dekarbonisierung des Verkehrs mithilfe von Leichtbau-Fahrzeugschwärmen}}}, year = {{2023}}, } @article{45602, author = {{Karakaya, Yasin and Somnitz, H. and Hermsen, A. and Gonchikzhapov, Munko and Kasper, Tina}}, issn = {{2666-352X}}, journal = {{Applications in Energy and Combustion Science}}, keywords = {{Metastable particles, Nanomaterials, Quartz-crystal-microbalance, Molecular-beam mass spectrometry, Tetramethylsilane, Reaction kinetics}}, publisher = {{Elsevier BV}}, title = {{{Revisiting the initial reaction rates for TMS combustion and a new evidence for metastable silica nanoparticles in the gas-phase synthesis}}}, doi = {{10.1016/j.jaecs.2023.100152}}, volume = {{14}}, year = {{2023}}, } @inbook{46691, author = {{Dahms, Frederik and Homberg, Werner}}, booktitle = {{Lecture Notes in Mechanical Engineering}}, isbn = {{9783031410222}}, issn = {{2195-4356}}, location = {{Cannes, France}}, publisher = {{Springer Nature Switzerland}}, title = {{{Analysis and Modelling of the Deformation in the Manufacture of Flange-Contours by the Combined Friction-Spinning and Flow-Forming Process}}}, doi = {{10.1007/978-3-031-41023-9_72}}, year = {{2023}}, } @misc{46753, abstract = {{Die Energieaufnahme von Haushaltskältegeräten ist seit den 1990er Jahren erheblich gesunken. Dieser Wert wird von den Herstellern im Neuzustand der Geräte unter Normbedingungen bestimmt. Wie jedes technische System unterliegen jedoch auch Haushaltskältegeräte einem Alterungsprozess, der zu einem Anstieg der Energieaufnahme über die Zeit führt. Im Rahmen dieser Dissertation wurde auf der Grundlage von 100 Messungen der Energieaufnahme, die an 32 Geräten über einen Zeitraum von 21 Jahren durchgeführt wurden, ein Alterungsmodell entwickelt. Dieses Modell ist das erste, das mit Hilfe von Daten der Energieaufnahme real gealterter Geräte entwickelt wurde. Es beschreibt einen Anstieg der Energieaufnahme von 27 % über die durchschnittliche Einsatzzeit eines Haushaltskältegeräts von 16 Jahren. Der stärkste Anstieg erfolgt in den ersten fünf Betriebsjahren. Durch Diffusionsvorgänge in dem im Gehäuse verbauten Polyurethan-Schaum wird das im Zellgas vorhandene Kohlenstoffdioxid durch Luft ersetzt. Hierdurch steigt die Wärmeleitfähigkeit des Schaums um ca. 33 % an, wodurch sich die Energieaufnahme der Geräte erhöht. Des Weiteren wurde der Einsatz von Paraffinen als Phasenwechselmaterial in Haushaltskältegeräten untersucht. Durch deren Einsatz konnte die Energieaufnahme gesenkt und die Funktionalität der Geräte gesteigert werden. Hierfür sind detaillierte Kenntnisse der Materialkenndaten der Paraffine notwendig. Die Wärmeleitfähigkeit der verschiedenen Paraffin-Stoffgruppen in der festen Phase ist jedoch bisher nur unzureichend untersucht worden. Daher wurde ein Messaufbau entwickelt, mit dem die Wärmeleitfähigkeit von festem Paraffin bestimmt werden kann, und es wurden entsprechende Messungen durchgeführt.}}, author = {{Paul, Andreas}}, publisher = {{LibreCat University}}, title = {{{Analyse von Alterungsmechanismen im Hinblick auf die Effizienz von Haushaltskältegeräten}}}, doi = {{10.17619/UNIPB/1-1784}}, year = {{2023}}, } @inproceedings{46762, author = {{Tchomgue Simeu, Arnold and Mahnken, Rolf}}, booktitle = {{XI International Conference on Adaptive Modeling and Simulation}}, publisher = {{CIMNE}}, title = {{{Mesh- and model adaptivity for elasto-plastic mean-field and full-field homogenization based on downwind and upwind approximations}}}, doi = {{10.23967/admos.2023.054}}, year = {{2023}}, } @inbook{46809, author = {{Rossel, M. and Meschut, G.}}, booktitle = {{Lecture Notes in Mechanical Engineering}}, isbn = {{9783031413407}}, issn = {{2195-4356}}, publisher = {{Springer Nature Switzerland}}, title = {{{Modeling and Parameterization for a 3D Simulation of Clinching with an Extensible Die}}}, doi = {{10.1007/978-3-031-41341-4_9}}, year = {{2023}}, } @book{46812, author = {{Rossel, Moritz Sebastian and Meschut, Gerson}}, pages = {{132}}, publisher = {{ Europäische Forschungsgesellschaft für Blechverarbeitung e.V.}}, title = {{{Methodenentwicklung zur verbesserten Prognosegüte beim Clinchen mit beweglicher Matrize in der numerischen Fügeprozesssimulation}}}, volume = {{598}}, year = {{2023}}, } @article{46815, abstract = {{In this work, the influence of the filler–matrix adhesion on the tensile properties of laser-sintered parts built with Polyamide 613 filled with glass beads was investigated. For this purpose, dry blends of glass beads with and without organosilane coupling agents and polyamide powder were prepared and processed into tensile specimens on an EOS P396 laser sintering system. The samples were tested both in the dry state and after an accelerated conditioning in a climate chamber. Furthermore, finite element method (FEM) simulations were performed to model the extreme cases of optimum adhesion and no adhesion. By correlating the tensile tests with the simulation results and by analyzing the fracture surfaces, it was shown that the filler–matrix adhesion is sufficient in the dry state but is strongly degraded by conditioning. Even the presence of various organosilane thin films could not prevent a strong deterioration of the filler–matrix adhesion and the associated deterioration of the mechanical properties. Since a comparison with an injection-molded sample of the same polymer filler combination shows identical behavior after conditioning, it is assumed that this problem is not limited to additively manufactured parts.}}, author = {{Kletetzka, Ivo and Kosanke, Maren and Meinderink, Dennis and Neßlinger, Vanessa and Grundmeier, Guido and Schmid, Hans-Joachim}}, issn = {{2363-9512}}, journal = {{Progress in Additive Manufacturing}}, keywords = {{Industrial and Manufacturing Engineering}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Influence of the filler–matrix adhesion and the effects of conditioning on tensile properties of laser-sintered parts built with polyamide–glass bead dry blends}}}, doi = {{10.1007/s40964-023-00501-z}}, year = {{2023}}, } @unpublished{43049, abstract = {{Abstract In this work, the influence of the filler matrix adhesion on the tensile properties of laser-sintered parts built with Polyamide 613 filled with glass beads was investigated. For this purpose, dry blends of glass beads with and without organosilane coupling agents and polyamide powder were prepared and processed into tensile specimens on an EOS P396. The samples were tested both in the dry state and after an accelerated conditioning in a climate chamber. Furthermore, FEM simulations were performed to model the limiting cases of optimum adhesion and no adhesion. By correlating the tensile tests with the simulation results and by analyzing the fracture surfaces, it was shown that the filler matrix adhesion is sufficient in the dry state but is strongly degraded by conditioning. Even the presence of various organosilane thin films could not prevent a strong deterioration of the filler-matrix adhesion and the associated deterioration of the mechanical properties. Since a comparison with an injection molded sample of the same polymer filler combination shows identical behavior after conditioning, it is assumed that this problem is not limited to additively manufactured parts.}}, author = {{Kletetzka, Ivo and Kosanke, Maren and Meinderink, Dennis and Neßlinger, Vanessa and Grundmeier, Guido and Schmid, Hans-Joachim}}, publisher = {{Research Square Platform LLC}}, title = {{{Influence of the filler matrix adhesion and the effects of conditioning on tensile properties of laser sintered parts built with polyamide glass bead dry blends}}}, year = {{2023}}, } @inproceedings{45783, author = {{Kletetzka, Ivo}}, location = {{Berlin}}, title = {{{Tensile Testing for Polymer AM - Best Pratice at the DMRC}}}, year = {{2023}}, } @article{43046, abstract = {{In the laser sintering technology, the semi-crystalline polymer material is exposed to elevated temperatures during processing, which leads to serious material ageing for most materials. This has already been investigated intensively by various authors. However, the ageing of the material at ambient temperatures during shelf life has not been the focus so far. The need to analyse the shelf life can be derived from an ecological and economic point of view. This work is focusing on the shelf life of PA2200 (PA12). To reduce the potential influences of powder production fluctuations, two different powder batches stored for 5.5 years and 6.5 years are investigated and compared to a reference powder produced 0.5 years before these investigations. Multiple powder analyses and part characterisations have been performed. A significant yellowing and molecular chain length reduction can be derived from the measurement results. Whereas the influence on mechanical part performance was minor, the parts built with the stored powders are more yellowish. As it is most likely that this is due to the consumption of polyamide stabilisers, it can be assumed that these parts will be subject to significantly faster ageing. Therefore, it is still not recommended to use the stored powders for critical parts or light intense and humid environments.}}, author = {{Klippstein, Sven Helge and Kletetzka, Ivo and Sural, Ilknur and Schmid, Hans-Joachim}}, journal = {{The International Journal of Advanced Manufacturing Technology }}, keywords = {{Selective laser sintering, Shelf life, Polyamide 12, powder, PA2200, material ageing}}, publisher = {{Springer}}, title = {{{Influence of a prolonged shelf time on PA12 laser sintering powder and resulting part properties}}}, doi = {{https://doi.org/10.1007/s00170-023-11243-1}}, year = {{2023}}, } @misc{46861, author = {{Sajadi, Said}}, title = {{{Charakterisierung und Bewertung von flammgeschützten PA12 Pulvermischungen hinsichtlich der Verarbeitbarkeit im Lasersinter-Prozess}}}, year = {{2023}}, } @inproceedings{46866, author = {{Troschitz, Juliane and Vorderbrüggen, Julian Heinrich Josef and Gude, Maik and Meschut, Gerson}}, booktitle = {{Proceedings of the 23rd International Conference on Composite Materials (ICCM23)}}, location = {{Belfast, UK}}, title = {{{Clinching and resistance spot welding of thermoplastic composites with metals using inserts as joining interfaces}}}, year = {{2023}}, } @inbook{46870, author = {{Menge, Dennis and Milaege, Dennis and Hoyer, Kay-Peter and Schmid, Hans-Joachim and Schaper, Mirko}}, booktitle = {{Climate Protection, Resource Efficiency, and Sustainable Engineering}}, editor = {{Horwath, Illona and Schweizer, Swetlana}}, isbn = {{9783837663778}}, issn = {{2703-1543}}, publisher = {{transcript Verlag}}, title = {{{Case Study IV: Individualized Medical Technology using Additive Manufacturing}}}, doi = {{10.14361/9783839463772-007}}, year = {{2023}}, } @inproceedings{28941, author = {{Afsahnoudeh, Reza and Holzmüller, Maik and Bader, Fabian and Homberg, Werner and Kenig, Eugeny Y.}}, location = {{Frankfurt am Main}}, title = {{{Numerische Untersuchung von Oberflächenstrukturierung zur Erhöhung der Effizienz von Kissenplatten-Wärmeübertragern}}}, year = {{2023}}, }