@inproceedings{33518, author = {{Gottschalk, Sebastian and Parvez, Sarmad and Yigitbas, Enes and Engels, Gregor}}, booktitle = {{Product-Focused Software Process Improvement - 23rd International Conference, {PROFES} 2022, Jyväskylä, Finland, Proceedings }}, title = {{{Designing Platforms for Crowd-based Software Prototype Validation: A Design Science Study}}}, year = {{2022}}, } @inproceedings{33515, author = {{Buschek, Daniel and Hauptmann, Hanna and Heuer, Hendrik and Loepp, Benedikt and Riener, Andreas and Yigitbas, Enes}}, booktitle = {{Proceedings of the Mensch Und Computer 2022 (MuC ’22) }}, title = {{{UCAI 2022 - 3rd International Workshop on User-Centered Artificial Intelligence}}}, year = {{2022}}, } @article{34006, author = {{Yigitbas, Enes and Gorissen, Simon and Weidmann, Nils and Engels, Gregor}}, journal = {{International Journal on Software and Systems Modeling (SoSyM) }}, title = {{{Design and Evaluation of a Collaborative UML Modeling Environment in Virtual Reality}}}, year = {{2022}}, } @inproceedings{30389, abstract = {{Online solvers for a series of standard 1-D or 2-D problems in integrated optics will be discussed. Implemented on the basis of HTML/JavaScript/SVG with core routines compiled from well tested C++-sources, the quasi-analytical algorithms require a computational load that can be handled easily even by current mobile devices. So far the series covers the 1-D guided modes of dielectric multilayer slab waveguides and the oblique plane wave reflection from these, the modes of rectangular channel waveguides (in an approximation of effective indices), bend modes of curved multilayer slabs, whispering-gallery resonances (“Quasi-Normal-Modes”) supported by circular dielectric cavities, the hybrid modes of circular multi-step-index optical fibers, bound and leaky modes of 1-D complex multilayers, including plasmonic surface modes, and, with restrictions, quite general rectangular scattering problems in 2-D.}}, author = {{Hammer, Manfred}}, booktitle = {{Integrated Optics: Devices, Materials, and Technologies XXVI}}, editor = {{García-Blanco, Sonia M. and Cheben, Pavel}}, keywords = {{tet_topic_waveguide}}, pages = {{1200414}}, publisher = {{SPIE}}, title = {{{Small-scale online simulations in guided-wave photonics}}}, doi = {{10.1117/12.2612208}}, year = {{2022}}, } @article{26627, abstract = {{Many-body perturbation theory based on density-functional theory calculations is used to determine the quasiparticle band structures and the dielectric functions of the isomorphic ferroelectrics rubidium titanyl phosphate (RbTiOPO4) and potassium titanyl arsenide (KTiOAsO4). Self-energy corrections of more than 2 eV are found to widen the transport band gaps of both materials considerably to 5.3 and 5.2 eV, respectively. At the same time, both materials are characterized by strong exciton binding energies of 1.4 and 1.5 eV, respectively. The solution of the Bethe-Salpeter equation based on the quasiparticle energies results in onsets of the optical absorption within the range of the measured data.}}, author = {{Neufeld, Sergej and Schindlmayr, Arno and Schmidt, Wolf Gero}}, issn = {{2515-7639}}, journal = {{Journal of Physics: Materials}}, number = {{1}}, publisher = {{IOP Publishing}}, title = {{{Quasiparticle energies and optical response of RbTiOPO4 and KTiOAsO4}}}, doi = {{10.1088/2515-7639/ac3384}}, volume = {{5}}, year = {{2022}}, } @article{33965, author = {{Bocchini, Adriana and Gerstmann, Uwe and Bartley, Tim and Steinrück, Hans-Georg and Henkel, Gerald and Schmidt, Wolf Gero}}, journal = {{Phys. Rev. Materials}}, pages = {{105401}}, publisher = {{American Physical Society}}, title = {{{Electrochemical performance of KTiOAsO_4 (KTA) in potassium-ion batteries from density-functional theory}}}, doi = {{10.1103/PhysRevMaterials.6.105401}}, volume = {{6}}, year = {{2022}}, } @article{31254, author = {{Bocchini, Adriana and Gerstmann, Uwe and Schmidt, Wolf Gero}}, journal = {{Phys. Rev. B}}, pages = {{205118}}, publisher = {{American Physical Society}}, title = {{{Oxygen vacancies in KTiOPO_4: Optical absorption from hybrid DFT}}}, doi = {{10.1103/PhysRevB.105.205118}}, volume = {{105}}, year = {{2022}}, } @article{34241, abstract = {{Due to the increasing use of multi-material constructions and the resulting material incompatibilities, mechanical joining technologies are gaining in importance. The reasons for this are the variety of joining possibilities as well as high load-bearing capacities. However, the currently rigid tooling systems cannot react to changing boundary conditions, such as changed sheet thicknesses or strength. For this reason, a large number of specialised joining processes have been developed to expand the range of applications. Using a versatile self-piercing riveting process, multi-material structures are joined in this paper. In this process, a modified tool actuator technology is combined with multi-range capable auxiliary joining parts. The multi-range capability of the rivets is achieved by forming the rivet head onto the respective thickness of the joining part combination without creating a tooling set-up effort. The joints are investigated both experimentally on the basis of joint formation and load-bearing capacity tests as well as by means of numerical simulation. It turned out that all the joints examined could be manufactured according to the defined standards. The load-bearing capacities of the joints are comparable to those of conventionally joined joints. In some cases the joint fails prematurely, which is why lower energy absorptions are obtained. However, the maximum forces achieved are higher than those of conventional joints. Especially in the case of high-strength materials arranged on the die side, the interlock formation is low. In addition, the use of die-sided sheets requires a large deformation of the rivet head protrusion, which leads to an increase in stress and, as a result, to damage if the rivet head. However, a negative influence on the joint load-bearing capacity could be excluded.}}, author = {{Kappe, Fabian and Wituschek, Simon and Bobbert, Mathias and Lechner, Michael and Meschut, Gerson}}, issn = {{0944-6524}}, journal = {{Production Engineering}}, keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Joining of multi-material structures using a versatile self-piercing riveting process}}}, doi = {{10.1007/s11740-022-01151-w}}, year = {{2022}}, } @inbook{34275, abstract = {{Due to economic and ecological requirements and the associated trend towards lightweight construction, mechanical joining technologies like self-piercing riveting are gaining in importance. In addition, the increase in lightweight multi-material joints has led to the development of many different mechanical joining technologies which can only be applied to join a small number of material combinations. This leads to low process efficiency, and in the case of self-piercing riveting, to a large number of required tool changes. Another approach focuses on reacting to changing boundary conditions as well as the creation of customised joints by using adaptive tools, versatile auxiliary joining parts or modified process kinematics. Therefore, this study investigates the influence of increased die-sided kinematics on joint formation in self-piercing riveting process. The aim is to achieve an improvement of the joint properties by superimposing the punch feed. Furthermore, it is intended to reduce required tool changes due to the improved joint design. The investigations were carried out by means of a 2D-axisymmetric numerical simulation model using the LS-Dyna simulation software. After the validation of the process model, the die was extended to include driven die elements. Using the model, different kinematics as well as their effects on the joint formation and the internal stress concentration could be analysed. In principle, the increased actuator technology enabled an increase of the interlock formation for both pure aluminium and multi-material joints consisting of steel and aluminium. However, the resulting process forces were higher during the process phases of punching and spreading.}}, author = {{Kappe, Fabian and Wituschek, Simon and de Pascalis, Vincenzo and Bobbert, Mathias and Lechner, Michael and Meschut, Gerson}}, booktitle = {{Materials Design and Applications IV}}, isbn = {{9783031181290}}, issn = {{1869-8433}}, publisher = {{Springer International Publishing}}, title = {{{Numerical Investigation of the Influence of a Movable Die Base on Joint Formation in Semi-tubular Self-piercing Riveting}}}, doi = {{10.1007/978-3-031-18130-6_10}}, year = {{2022}}, } @article{34244, author = {{Kappe, Fabian and Zirngibl, Christoph and Schleich, Benjamin and Bobbert, Mathias and Wartzack, Sandro and Meschut, Gerson}}, issn = {{1526-6125}}, journal = {{Journal of Manufacturing Processes}}, keywords = {{Industrial and Manufacturing Engineering, Management Science and Operations Research, Strategy and Management}}, pages = {{1438--1448}}, publisher = {{Elsevier BV}}, title = {{{Determining the influence of different process parameters on the versatile self-piercing riveting process using numerical methods}}}, doi = {{10.1016/j.jmapro.2022.11.019}}, volume = {{84}}, year = {{2022}}, } @article{29858, author = {{Kappe, Fabian and Schadow, Luca and Bobbert, Mathias and Meschut, Gerson}}, journal = {{Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications}}, title = {{{Increasing flexibility of self-piercing riveting by reducing tool–geometry combinations using cluster analysis in the application of multi-material design}}}, doi = {{10.1177/14644207211070992}}, year = {{2022}}, } @article{29857, author = {{Kappe, Fabian and Wituschek, Simon and Bobbert, Mathias and Meschut, Gerson}}, journal = {{Production Engineering}}, title = {{{Determining the properties of multi‑range semi‑tubular self‑piercing riveted joints}}}, doi = {{https://doi.org/10.1007/s11740-022-01105-2}}, year = {{2022}}, } @article{34403, abstract = {{For a reliable, strength-compliant and fracture-resistant design of components and technical structures and for the prevention of damage cases, both the criteria of strength calculation and fracture mechanics are essential. In contrast to strength calculation the fracture mechanics assumes the existence of cracks which might further propagate due to the operational load. First, the present paper illustrates the general procedure of a fracture mechanical evaluation of fatigue cracks in order to assess practical damage cases. Fracture mechanical fundamentals which are essential for the calculation of the stress intensity factors K I and the experimental determination of fracture mechanical material parameters (e.g. threshold ΔK I,th against fatigue crack growth, crack growth rate curve) are explained in detail. The subsequent fracture mechanical evaluation on the basis of the local stress situation at the crack tip and the fracture mechanical material data is executed for different materials and selected crack problems. Hereby, the main focus is on the material HCT590X as it is the essential material being investigated by TRR285.}}, author = {{Schramm, Britta and Weiß, Deborah}}, issn = {{0025-5300}}, journal = {{Materials Testing}}, keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}}, number = {{10}}, pages = {{1437--1449}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{Fracture mechanical evaluation of the material HCT590X}}}, doi = {{10.1515/mt-2022-0191}}, volume = {{64}}, year = {{2022}}, } @inproceedings{33981, author = {{Ehlert, Meik and Henke, Christian and Trächtler, Ansgar}}, booktitle = {{Proceedings of the 12th International Conference on Simulation and Modeling Methodologies, Technologies and Applications}}, publisher = {{SCITEPRESS - Science and Technology Publications}}, title = {{{Analysis of Differential Algebraic Equation Systems for Connecting Energy Storages of Generally Valid Functional Mock-up Units}}}, doi = {{10.5220/0011305700003274}}, year = {{2022}}, } @inproceedings{30263, abstract = {{High-strength wire materials are usually available as strip material which is further processed in a forming process (e.g. punch-bending). For storage and transport of the semi-finished wire to the customer, the material is wound onto coils. The manufacturing and coiling process introduces plastic deformations into the wire, which lead to undesirable residual stresses and wire curvature of the semi-finished product. These residual stresses and curvatures cause variations in the material properties of the semi-finished product, which have a negative impact on the subsequent product quality. Straightening machines are used to compensate the residual stresses and the curvature in the wire. At the beginning of the straightening process, the straightening machines must be set up in such a way that residual stresses and curvatures are optimally compensated. This setup process is usually a manual and iterative process, where a lot of material is wasted until the optimal settings for the straightening machine are found.In order to reduce the amount of material waste, the operator must be supported in the setup process. In this context, a new and innovative setup assistance system was developed to support the operator during the setup process. The setup assistant system automatically detects the wire curvature by means of an optical measuring system. Based on the optically detected measuring points, the wire curvature is determined by a robust calculation algorithm. Based on a database built up through the carried out experimental and numerical research work, the optimum setting parameters for the straightening machine are suggested to the operator without lengthy trial and error. After confirmation by the operator, the roller settings are automatically adjusted by the mechatronic straightening machine. With the presented method, the conventional iterative setup procedure can be made more resource-efficient and a high straightening quality can be reproducibly achieved. }}, author = {{Bathelt, Lukas and Bader, Fabian and Djakow, Eugen and Henke, Christian and Trächtler, Ansgar and Homberg, Werner}}, location = {{Braga / Portugal}}, title = {{{Innovative assistance system for setting up a mechatronic straightening machine}}}, doi = {{https://doi.org/10.4028/p-vs07w9}}, year = {{2022}}, } @inproceedings{30265, abstract = {{Due to increasing globalization and rising quality requirements, the steel and metal processing industry is facing growing cost and innovation pressure. Not least because of their high lightweight potential, high-strength steel materials are meeting the growing material requirements of steel and metal processing in areas such as aerospace and medical technology. In particular, the tight tolerance limits of applicable shape and dimensional accuracies pose a challenge in the processing of high-strength steel strip materials. Improving the processability of high-strength steel materials through the use of straighteners with set-up assistance systems significantly increases the potential for competing with other materials such as aluminum or magnesium alloys. }}, author = {{Bader, Fabian and Bathelt, Lukas and Djakow, Eugen and Henke, Christian and Homberg, Werner and Trächtler, Ansgar}}, location = {{Braga / Portugal}}, title = {{{An approach for an innovative 3d steel strip straightening machine for curvature and saber compensation}}}, doi = {{https://doi.org/10.4028/p-87wvu0}}, year = {{2022}}, } @article{33982, author = {{Koppert, Steven and Henke, Christian and Trächtler, Ansgar and Möhringer, Stefan}}, issn = {{2405-8963}}, journal = {{IFAC-PapersOnLine}}, keywords = {{Control and Systems Engineering}}, number = {{2}}, pages = {{554--560}}, publisher = {{Elsevier BV}}, title = {{{Tool Wear Monitoring of a Tree Log Bandsaw using a Deep Convolutional Neural Network on challenging data}}}, doi = {{10.1016/j.ifacol.2022.04.252}}, volume = {{55}}, year = {{2022}}, } @inproceedings{33978, author = {{Bathelt, Lukas and Bader, Fabian and Djakow, Eugen and Henke, Christian and Trächtler, Ansgar and Homberg, Werner}}, booktitle = {{Fachtagung VDI MECHATRONIK 2022 }}, location = {{Darmstadt}}, pages = {{19--24}}, title = {{{Mechatronische Richtapparate: Intelligente Richttechnik von hochfesten Flachdrähten}}}, year = {{2022}}, } @inproceedings{33469, author = {{Schütz, Stefan and Schmidt, Robin and Henke, Christian and Trächtler, Ansgar}}, booktitle = {{2022 IEEE International Systems Conference (SysCon)}}, location = {{Montreal, QC, Canada}}, pages = {{1--8}}, publisher = {{IEEE}}, title = {{{Virtual Commissioning of the Trajectory Tracking Control of a Sensor-Guided, Kinematically Redundant Robotic Welding System on a PLC}}}, doi = {{10.1109/syscon53536.2022.9773878}}, year = {{2022}}, } @inproceedings{33976, author = {{Lenz, Cederic and Hanke, Fabian and Henke, Christian and Trächtler, Ansgar}}, booktitle = {{2022 27th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA )}}, location = {{Stuttgart, Germany }}, publisher = {{IEEE}}, title = {{{Anomaly Detection in Hot Forming Processes using Hybrid Modeling - Part II}}}, doi = {{10.1109/ETFA52439.2022.9921510}}, year = {{2022}}, }