@article{34216, abstract = {{Mechanical joining technologies are increasingly used in multi-material lightweight constructions and offer opportunities to create versatile joining processes due to their low heat input, robustness to metallurgical incompatibilities and various process variants. They can be categorised into technologies which require an auxiliary joining element, or do not require an auxiliary joining element. A typical example for a mechanical joining process with auxiliary joining element is self-piercing riveting. A wide range of processes exist which are not requiring an auxiliary joining element. This allows both point-shaped (e.g., by clinching) and line-shaped (e.g., friction stir welding) joints to be produced. In order to achieve versatile processes, challenges exist in particular in the creation of intervention possibilities in the process and the understanding and handling of materials that are difficult to join, such as fiber reinforced plastics (FRP) or high-strength metals. In addition, predictive capability is required, which in particular requires accurate process simulation. Finally, the processes must be measured non-destructively in order to generate control variables in the process or to investigate the cause-effect relationship. This paper covers the state of the art in scientific research concerning mechanical joining and discusses future challenges on the way to versatile mechanical joining processes.}}, author = {{Meschut, Gerson and Merklein, M. and Brosius, A. and Drummer, D. and Fratini, L. and Füssel, U. and Gude, M. and Homberg, Werner and Martins, P.A.F. and Bobbert, Mathias and Lechner, M. and Kupfer, R. and Gröger, B. and Han, Daxin and Kalich, J. and Kappe, Fabian and Kleffel, T. and Köhler, D. and Kuball, C.-M. and Popp, J. and Römisch, D. and Troschitz, J. and Wischer, Christian and Wituschek, S. and Wolf, M.}}, issn = {{2666-3309}}, journal = {{Journal of Advanced Joining Processes}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{Review on mechanical joining by plastic deformation}}}, doi = {{10.1016/j.jajp.2022.100113}}, volume = {{5}}, year = {{2022}}, } @article{32275, author = {{Meschut, G. and Merklein, M. and Brosius, A. and Drummer, D. and Fratini, L. and Füssel, U. and Gude, M. and Homberg, W. and Martins, P.A.F. and Bobbert, M. and Lechner, M. and Kupfer, R. and Gröger, B. and Han, D. and Kalich, J. and Kappe, F. and Kleffel, T. and Köhler, D. and Kuball, C.-M. and Popp, J. and Römisch, D. and Troschitz, J. and Wischer, C. and Wituschek, S. and Wolf, M.}}, issn = {{2666-3309}}, journal = {{Journal of Advanced Joining Processes}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{Review on mechanical joining by plastic deformation}}}, doi = {{10.1016/j.jajp.2022.100113}}, volume = {{5}}, year = {{2022}}, } @article{34224, abstract = {{Crack growth in structures depends on the cyclic loads applied on it, such as mechanical, thermal and contact, as well as residual stresses, etc. To provide an accurate simulation of crack growth in structures, it is of high importance to integrate all kinds of loading situations in the simulations. Adapcrack3D is a simulation program that can accurately predict the propagation of cracks in real structures. However, until now, this three-dimensional program has only considered mechanical loads and static thermal loads. Therefore, the features of Adapcrack3D have been extended by including contact loading in crack growth simulations. The numerical simulation of crack propagation with Adapcrack3D is generally carried out using FE models of structures provided by the user. For simulating models with contact loading situations, Adapcrack3D has been updated to work with FE models containing multiple parts and necessary features such as coupling and surface interactions. Because Adapcrack3D uses the submodel technique for fracture mechanical evaluations, the architecture of the submodel is also modified to simulate models with contact definitions between the crack surfaces. This paper discusses the newly implemented attribute of the program with the help of illustrative examples. The results confirm that the contact simulation in Adapcrack3D is a major step in improving the functionality of the program.}}, author = {{Joy, Tintu David and Weiß, Deborah and Schramm, Britta and Kullmer, Gunter}}, issn = {{2076-3417}}, journal = {{Applied Sciences}}, keywords = {{Fluid Flow and Transfer Processes, Computer Science Applications, Process Chemistry and Technology, General Engineering, Instrumentation, General Materials Science}}, number = {{15}}, publisher = {{MDPI AG}}, title = {{{Further Development of 3D Crack Growth Simulation Program to Include Contact Loading Situations}}}, doi = {{10.3390/app12157557}}, volume = {{12}}, year = {{2022}}, } @inproceedings{39372, author = {{Lange, Sven and Hedayat, Christian and Kuhn, Harald and Hilleringmann, Ulrich}}, booktitle = {{2022 Smart Systems Integration (SSI)}}, publisher = {{IEEE}}, title = {{{Modeling and Characterization of a 3D Environment for the Design of an Inductively Based Locating Method by Coil Couplings}}}, doi = {{10.1109/ssi56489.2022.9901416}}, year = {{2022}}, } @inproceedings{39373, author = {{Lange, Sven and Hedayat, Christian and Kuhn, Harald and Hilleringmann, Ulrich}}, booktitle = {{2022 Smart Systems Integration (SSI)}}, publisher = {{IEEE}}, title = {{{Modeling and Characterization of a 3D Environment for the Design of an Inductively Based Locating Method by Coil Couplings}}}, doi = {{10.1109/ssi56489.2022.9901416}}, year = {{2022}}, } @inproceedings{39375, author = {{Lange, Sven and Hedayat, Christian and Kuhn, Harald and Hilleringmann, Ulrich}}, booktitle = {{2022 Smart Systems Integration (SSI)}}, publisher = {{IEEE}}, title = {{{Modeling and Characterization of a 3D Environment for the Design of an Inductively Based Locating Method by Coil Couplings}}}, doi = {{10.1109/ssi56489.2022.9901416}}, 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}}, } @inbook{34210, abstract = {{The application of the mechanical joining process clinching enables the joining of sheet metals with a wide range of material-thickness configurations, which is of interest in lightweight construction of multi-material structures. Each material-thickness combination results in a joint with its own property profile that is affected differently by variations. Manufacturing process-related effects from preforming steps influence the geometric shape of a clinched joint as well as its load-bearing capacity. During the clinching process high degrees of plastic strain, increased temperatures and high strain rates occur. In this context, a 3D numerical model was developed which can represent the material-specific behaviour during the process chain steps sheet metal forming, joining, and loading phase in order to achieve a high predictive accuracy of the simulation. Besides to the investigation of the prediction accuracy, the extent of the influence of individual modelling aspects such as temperature and strain rate dependency is examined.}}, author = {{Bielak, Christian Roman and Böhnke, Max and Bobbert, Mathias and Meschut, Gerson}}, booktitle = {{The Minerals, Metals & Materials Series}}, isbn = {{9783031062117}}, issn = {{2367-1181}}, publisher = {{Springer International Publishing}}, title = {{{Development of a Numerical 3D Model for Analyzing Clinched Joints in Versatile Process Chains}}}, doi = {{10.1007/978-3-031-06212-4_15}}, 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{41500, abstract = {{Titanium alloys, especially β alloys, are favorable as implant materials due to their promising combination of low Young’s modulus, high strength, corrosion resistance, and biocompatibility. In particular, the low Young’s moduli reduce the risk of stress shielding and implant loosening. The processing of Ti-24Nb-4Zr-8Sn through laser powder bed fusion is presented. The specimens were heat-treated, and the microstructure was investigated using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The mechanical properties were determined by hardness and tensile tests. The microstructures reveal a mainly β microstructure with α″ formation for high cooling rates and α precipitates after moderate cooling rates or aging. The as-built and α″ phase containing conditions exhibit a hardness around 225 HV5, yield strengths (YS) from 340 to 490 MPa, ultimate tensile strengths (UTS) around 706 MPa, fracture elongations around 20%, and Young’s moduli about 50 GPa. The α precipitates containing conditions reveal a hardness around 297 HV5, YS around 812 MPa, UTS from 871 to 931 MPa, fracture elongations around 12%, and Young’s moduli about 75 GPa. Ti-24Nb-4Zr-8Sn exhibits, depending on the heat treatment, promising properties regarding the material behavior and the opportunity to tailor the mechanical performance as a low modulus, high strength implant material.}}, author = {{Hein, Maxwell and Lopes Dias, Nelson Filipe and Pramanik, Sudipta and Stangier, Dominic and Hoyer, Kay-Peter and Tillmann, Wolfgang and Schaper, Mirko}}, issn = {{1996-1944}}, journal = {{Materials}}, keywords = {{General Materials Science}}, number = {{11}}, publisher = {{MDPI AG}}, title = {{{Heat Treatments of Metastable β Titanium Alloy Ti-24Nb-4Zr-8Sn Processed by Laser Powder Bed Fusion}}}, doi = {{10.3390/ma15113774}}, volume = {{15}}, year = {{2022}}, } @article{30962, abstract = {{ Clinching as a mechanical joining process has become established in many areas of car body. In order to predict relevant properties of clinched joints and to ensure the reliability of the process, it is numerically simulated during the product development process. The prediction accuracy of the simulated process depends on the implemented friction model. Therefore, a new method for determining friction coefficients in sheet metal materials was developed and tested. The aim of this study is the numerical investigation of this experimental method by means of FE simulation. The experimental setup is modelled in a 3D numerical simulation taking into account the process parameters varying in the experiment, such as geometric properties, contact pressure and contact velocity. Furthermore, the contact description of the model is calibrated via the experimentally determined friction coefficients according to clinch-relevant parameter space. It is shown that the assumptions made in the determination of the experimental data in preliminary work are valid. In addition, it is investigated to what extent the standard Coulomb friction model in the FEM can reproduce the results of the experimental method. }}, author = {{Bielak, Christian Roman and Böhnke, Max and Bobbert, Mathias and Meschut, Gerson}}, issn = {{1464-4207}}, journal = {{Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications}}, keywords = {{Mechanical Engineering, General Materials Science}}, publisher = {{SAGE Publications}}, title = {{{Numerical investigation of a friction test to determine the friction coefficients for the clinching process}}}, doi = {{10.1177/14644207221093468}}, year = {{2022}}, } @article{29951, abstract = {{The components of a body in white consist of many individual thin-walled sheet metal parts, which usually are manufactured in deep-drawing processes. In general, the conditions in a deep-drawing process change due to changing tribology conditions, varying degrees of spring back, or scattering material properties in the sheet blanks, which affects the resulting pre-strain. Mechanical joining processes, especially clinching, are influenced by these process-related pre-strains. The final geometric shape of a clinched joint is affected to a significant level by the prior material deformation when joining with constant process parameters. That leads to a change in the stiffness and force transmission in the clinched joint due to the different geometric dimensions, such as interlock, neck thickness and bottom thickness, which directly affect the load bearing capacity. Here, the influence of the pre-straining in the deep drawing process on the force distribution in clinch points in an automotive assembly is investigated by finite-element models numerically. In further studies, the results are implemented in an optimization tool for designing clinched components. The methodology starts with a pre-straining of metal sheets. This step is followed by 2D rotationally symmetric forming simulations of the joining process. The resulting mesh of each forming simulation is rotated and 3D models are obtained. The clinched joint solid model with pre-strains is used further to determine the joint stiffnesses. With the simulation of the same test set-up with an equivalent point-connector model, the equivalent stiffness for each pre-strain combination is determined. Simulations are performed on a clinched component to assess the influence of pre-strain and sheet thinning on the clinched joint loadings by using the equivalent stiffnesses. The investigations clearly show that for the selected component, the loadings at the clinch points are dependent on the sheet thinning and the stiffnesses due to pre-strain. The magnitude of the influence varies depending on the quantity considered. For example, the shear force is more sensitive to the joint stiffness than to the sheet thinning.}}, author = {{Martin, Sven and Bielak, Christian Roman and Bobbert, Mathias and Tröster, Thomas and Meschut, Gerson}}, issn = {{0944-6524}}, journal = {{Production Engineering}}, keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Numerical investigation of the clinched joint loadings considering the initial pre-strain in the joining area}}}, doi = {{10.1007/s11740-021-01103-w}}, year = {{2022}}, } @techreport{44634, author = {{Roth, M. M. and Holmarsdottir, H. B. and Labusch, Amelie and Eickelmann, Birgit and Parsanoglou, D.}}, title = {{{Good practice toolkit for improving practice and policies (DigiGen-working paper).}}}, year = {{2022}}, } @inproceedings{32389, author = {{Rossel, Moritz Sebastian and Meschut, Gerson}}, location = {{Toronto}}, title = {{{Increasing the Prediction Quality of Clinching Process Simulation with Extensible Die by Means of Friction Modeling as a Function of the Local Joining Process Parameters}}}, year = {{2022}}, } @inproceedings{45679, author = {{Bruns, Julia and Reuter, D.}}, booktitle = {{Beiträge zum Mathematikunterricht 2022}}, publisher = {{WTM-Verlag}}, title = {{{„Ich hab als Erstes die angeguckt“ – Muster- und Strukturerkennung mit Eye-Tracking besser verstehen?}}}, year = {{2022}}, } @inbook{45347, author = {{Herding, Jana and Kamin, A.M. and Büker, P. and Glawe, K. and Menke, I. and Schaper, F.}}, booktitle = {{Inklusion digital! Chancen und Herausforderungen inklusiver Bildung im Kontext von Digitalisierung}}, editor = {{Ferencik-Lehmkuhl, D. and Huynh, I. and Laubmeister, C. and Lee, C. and Melzer, C. and Schwank, I. and Weck, H. and Ziemen, K.}}, pages = {{228--246}}, publisher = {{Verlag Julius Klinkhardt}}, title = {{{Inklusions- und digitalisierungsbezogene Kompetenzen im Lehramtsstudium erwerben – Konzeption, Erprobung und Evaluation der Lehr-/Lernumgebung inklud.nrw}}}, year = {{2022}}, } @article{46121, author = {{Altenkort, Luis and Eller, Alexander M. and Kaczmarek, O. and Mazur, Lukas and Moore, Guy D. and Shu, Hai-Tao}}, issn = {{2470-0010}}, journal = {{Physical Review D}}, number = {{9}}, publisher = {{American Physical Society (APS)}}, title = {{{Lattice QCD noise reduction for bosonic correlators through blocking}}}, doi = {{10.1103/physrevd.105.094505}}, volume = {{105}}, year = {{2022}}, } @article{40987, abstract = {{There is an increasing interest in sensing applications for a variety of analytes in aqueous environments, as conventional methods do not work reliably under humid conditions or they require complex equipment with experienced operators. Hydrogel sensors are easy to fabricate, are incredibly sensitive, and have broad dynamic ranges. Experiments on their robustness, reliability, and reusability have indicated the possible long-term applications of these systems in a variety of fields, including disease diagnosis, detection of pharmaceuticals, and in environmental testing. It is possible to produce hydrogels, which, upon sensing a specific analyte, can adsorb it onto their 3D-structure and can therefore be used to remove them from a given environment. High specificity can be obtained by using molecularly imprinted polymers. Typical detection principles involve optical methods including fluorescence and chemiluminescence, and volume changes in colloidal photonic crystals, as well as electrochemical methods. Here, we explore the current research utilizing hydrogel-based sensors in three main areas: (1) biomedical applications, (2) for detecting and quantifying pharmaceuticals of interest, and (3) detecting and quantifying environmental contaminants in aqueous environments.}}, author = {{Völlmecke, Katharina and Afroz, Rowshon and Bierbach, Sascha and Brenker, Lee Josephine and Frücht, Sebastian and Glass, Alexandra and Giebelhaus, Ryland and Hoppe, Axel and Kanemaru, Karen and Lazarek, Michal and Rabbe, Lukas and Song, Longfei and Velasco Suarez, Andrea and Wu, Shuang and Serpe, Michael and Kuckling, Dirk}}, issn = {{2310-2861}}, journal = {{Gels}}, number = {{12}}, publisher = {{MDPI AG}}, title = {{{Hydrogel-Based Biosensors}}}, doi = {{10.3390/gels8120768}}, volume = {{8}}, year = {{2022}}, }