@article{52612, abstract = {{During resistance spot welding of zinc-coated advanced high-strength steels (AHSSs) for automotive production, liquid metal embrittlement (LME) cracking may occur in the event of a combination of various unfavorable influences. In this study, the interactions of different welding current levels and weld times on the tendency for LME cracking in third-generation AHSSs were investigated. LME manifested itself as high-penetration cracks around the circumference of the spot welds for welding currents closely below the expulsion limit. At the same time, the observed tendency for LME cracking showed no direct correlation with the overall heat input of the investigated welding processes. To identify a reliable indicator of the tendency for LME cracking, the local strain rate at the origin of the observed cracks was analyzed over the course of the welding process via finite element simulation. While the local strain rate showed a good correlation with the process-specific LME cracking tendency, it was difficult to interpret due to its discontinuous course. Therefore, based on the experimental measurement of electrode displacement during welding, electrode indentation velocity was proposed as a descriptive indicator for quantifying cracking tendency.}}, author = {{Böhne, Christoph and Meschut, Gerson and BIEGLER, MAX and RETHMEIER, MICHAEL}}, issn = {{0043-2296}}, journal = {{Welding Journal}}, keywords = {{Metals and Alloys, Mechanical Engineering, Mechanics of Materials}}, number = {{7}}, pages = {{197--207}}, publisher = {{American Welding Society}}, title = {{{The Influence of Electrode Indentation Rate on LME Formation during RSW}}}, doi = {{10.29391/2022.101.015}}, volume = {{101}}, year = {{2022}}, } @inproceedings{32875, author = {{Ostermann, Moritz and Behm, Jonathan and Marten, Thorsten and Tröster, Thomas and Weyer, Johannes and Cepera, Kay and Adelt, Fabian}}, booktitle = {{14. Wissenschaftsforum Mobilität}}, location = {{Duisburg}}, title = {{{Individualisierung des ÖPNV - Integration technischer und sozialer Dimensionen nachhaltiger Mobilität}}}, year = {{2022}}, } @misc{52428, author = {{Schlüter, Alexander}}, publisher = {{Marcus Nettelbeck}}, title = {{{2050 - The Future Podcast, Folge Smarte Energien für die Zukunft}}}, year = {{2022}}, } @inproceedings{26389, abstract = {{Within this work, we investigate how data-driven numerical approximation methods of the Koopman operator can be used in practical control engineering applications. We refer to the method Extended Dynamic Mode Decomposition (EDMD), which approximates a nonlinear dynamical system as a linear model. This makes the method ideal for control engineering applications, because a linear system description is often assumed for this purpose. Using academic examples, we simulatively analyze the prediction performance of the learned EDMD models and show how relevant system properties like stability, controllability, and observability are reflected by the EDMD model, which is a critical requirement for a successful control design process. Subsequently, we present our experimental results on a mechatronic test bench and evaluate the applicability to the control engineering design process. As a result, the investigated methods are suitable as a low-effort alternative for the design steps of model building and adaptation in the classical model-based controller design method.}}, author = {{Junker, Annika and Timmermann, Julia and Trächtler, Ansgar}}, booktitle = {{2022 3rd International Conference on Artificial Intelligence, Robotics and Control (AIRC 2022)}}, isbn = {{978-1-6654-5946-4}}, keywords = {{Koopman Operator, Nonlinear Control, Extended Dynamic Mode Decomposition, Hybrid Modelling}}, location = {{Cairo, Egypt}}, pages = {{1--9}}, title = {{{Data-Driven Models for Control Engineering Applications Using the Koopman Operator}}}, doi = {{10.1109/AIRC56195.2022.9836980}}, year = {{2022}}, } @inproceedings{34011, author = {{Junker, Annika and Fittkau, Niklas and Timmermann, Julia and Trächtler, Ansgar}}, booktitle = {{Proceedings - 32. Workshop Computational Intelligence: Berlin, 1. - 2. Dezember 2022}}, location = {{Berlin, Germany}}, pages = {{119--124}}, title = {{{Autonomes Putten mittels datengetriebener und physikbasierter Methoden}}}, doi = {{10.5445/KSP/1000151141}}, year = {{2022}}, } @article{50071, author = {{Junker, Annika and Timmermann, Julia and Trächtler, Ansgar}}, issn = {{2405-8963}}, journal = {{IFAC-PapersOnLine}}, keywords = {{Control and Systems Engineering}}, number = {{12}}, pages = {{389--394}}, publisher = {{Elsevier BV}}, title = {{{Learning Data-Driven PCHD Models for Control Engineering Applications*}}}, doi = {{10.1016/j.ifacol.2022.07.343}}, volume = {{55}}, year = {{2022}}, } @inproceedings{33914, abstract = {{Workshops on business model generation lead to collaborative work phases and discussions on business models. Therefore, tools such as the Business Model Canvas are used, typically filled with sticky notes. Generated content needs to be digitized in a time-consuming manual follow-up as part of the documentation and basis for a further use of the results in the company. In addition, there are challenges, such as decentralized work and digital workshop formats. Augmented Reality offers a way to reduce the digitization effort and enables decentralized work. In this research, the potentials of the use of AR technology in workshops on business model generation is investigated. Therefore, functions are implemented and evaluated in a demonstrator that reduces digitization effort and enable distributed work.}}, author = {{Gräßler, Iris and Grewe, Benedikt and Kramer, Hendrik and Pottebaum, Jens}}, booktitle = {{LUT Scientific and Expertise Publications}}, keywords = {{business model generation, augmented reality, workshop, collaborative work, digitization, AR-supported workshop concept, immersive technologies, decentralized work, business model canvas}}, location = {{Copenhagen}}, title = {{{Supporting Business Model Generation with Augmented Reality}}}, year = {{2022}}, } @misc{50089, author = {{Pauls, Karina}}, booktitle = {{Lexikon der Kunstpädagogik}}, editor = {{Bering, Kunibert and Niehoff, Rolf and Pauls, Karina}}, isbn = {{978-3-8252-5954-9}}, pages = {{481--485}}, publisher = {{ATHENA/wbv}}, title = {{{Skulptur/Plastik}}}, volume = {{5954}}, year = {{2022}}, } @article{36332, abstract = {{AlSi casting alloys combine excellent castability with high strength. Hence, this group of alloys is often used in the automotive sector. The challenge for this application is the brittle character of these alloys which leads to cracks during joint formation when mechanical joining technologies are used. A rise in ductility can be achieved by a considerable increase in the solidification rate which results in grain refinement. High solidification rates can be realized in twin–roll casting (TRC) by water-cooled rolls. Therefore, a hypoeutectic EN AC–AlSi9 (for European Norm - aluminum cast product) is manufactured by the TRC process and analyzed. Subsequently, joining investigations are performed on castings in as-cast and heat-treated condition using the self-piercing riveting process considering the joint formation and the load-bearing capacity. Due to the fine microstructure, the crack initiation can be avoided during joining, while maintaining the joining parameters, especially by specimens in heat treatment conditions. Furthermore, due to the extremely fine microstructure, the load-bearing capacity of the joint can be significantly increased in terms of the maximum load-bearing force and the energy absorbed.}}, author = {{Neuser, Moritz and Kappe, Fabian and Ostermeier, Jakob and Krüger, Jan Tobias and Bobbert, Mathias and Meschut, Gerson and Schaper, Mirko and Grydin, Olexandr}}, issn = {{1438-1656}}, journal = {{Advanced Engineering Materials}}, keywords = {{Condensed Matter Physics, General Materials Science}}, number = {{10}}, publisher = {{Wiley}}, title = {{{Mechanical Properties and Joinability of AlSi9 Alloy Manufactured by Twin‐Roll Casting}}}, doi = {{10.1002/adem.202200874}}, volume = {{24}}, year = {{2022}}, } @article{37647, abstract = {{Mechanical joining processes are an essential part of modern lightweight construction. They permit materials of different types to be joined in a way that is suitable for the loads involved. These processes reach their limits, however, as soon as the boundary conditions change. In most cases, these elements are specially adapted to the joining point and cannot be used universally. Changes require cost-intensive adaptation of both the element and the process control, thus making production more complex. This results in high costs due to the increased number of auxiliary joining element variants required and reduces the economic efficiency of mechanical joining. One approach to overcoming this issue is the use of adaptive auxiliary joining elements formed by friction spinning. This article presents the current state of research on pre-hole-free joining with adaptive joining elements. The overall process chain is illustrated, explained and analyzed. Special attention is paid to demonstrating the feasibility of pre-hole-free joining with adaptive joining elements. The chosen mechanical parameters are subsequently listed. Finally, a comprehensive outlook of the future development potential is derived.}}, author = {{Wischer, Christian and Homberg, Werner}}, issn = {{1662-9795}}, journal = {{Key Engineering Materials}}, keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}}, pages = {{1468--1478}}, publisher = {{Trans Tech Publications, Ltd.}}, title = {{{Further Development of an Adaptive Joining Technique Based on Friction Spinning to Produce Pre-Hole-Free Joints}}}, doi = {{10.4028/p-1n6741}}, volume = {{926}}, year = {{2022}}, } @article{30963, abstract = {{In this paper, a study based on experimental and numerical simulations is performed to analyze fatigue cracks in clinched joints. An experimental investigation is conducted to determine the failure modes of clinched joints under cyclic loading at different load amplitudes with single-lap shear tests. In addition, numerical FEM simulations of clinching process and subsequent shear loading are performed to support the experimental investigations by analyzing the state of stresses at the location of failure. An attempt is made to explain the location of crack initiation in the experiments using evaluation variables such as contact shear stress and maximum principal stress.}}, author = {{Ewenz, Lars and Bielak, Christian Roman and Otroshi, Mortaza and Bobbert, Mathias and Meschut, Gerson and Zimmermann, Martina}}, issn = {{0944-6524}}, journal = {{Production Engineering}}, keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering}}, number = {{2-3}}, pages = {{305--313}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Numerical and experimental identification of fatigue crack initiation sites in clinched joints}}}, doi = {{10.1007/s11740-022-01124-z}}, volume = {{16}}, year = {{2022}}, } @article{34069, author = {{Schramm, Britta and Martin, Sven and Steinfelder, Christian and Bielak, Christian Roman and Brosius, Alexander and Meschut, Gerson and Tröster, Thomas and Wallmersperger, Thomas and Mergheim, Julia}}, issn = {{2666-3309}}, journal = {{Journal of Advanced Joining Processes}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{A Review on the Modeling of the Clinching Process Chain - Part I: Design Phase}}}, doi = {{10.1016/j.jajp.2022.100133}}, volume = {{6}}, year = {{2022}}, } @article{34068, author = {{Schramm, Britta and Friedlein, Johannes and Gröger, Benjamin and Bielak, Christian Roman and Bobbert, Mathias and Gude, Maik and Meschut, Gerson and Wallmersperger, Thomas and Mergheim, Julia}}, issn = {{2666-3309}}, journal = {{Journal of Advanced Joining Processes}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{A Review on the Modeling of the Clinching Process Chain - Part II: Joining Process}}}, doi = {{10.1016/j.jajp.2022.100134}}, year = {{2022}}, } @article{34070, author = {{Schramm, Britta and Harzheim, Sven and Weiß, Deborah and Joy, Tintu David and Hofmann, Martin and Mergheim, Julia and Wallmersperger, Thomas}}, issn = {{2666-3309}}, journal = {{Journal of Advanced Joining Processes}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{A Review on the Modeling of the Clinching Process Chain - Part III: Operational Phase}}}, doi = {{10.1016/j.jajp.2022.100135}}, year = {{2022}}, } @article{31238, author = {{Kupfer, Robert and Köhler, Daniel and Römisch, David and Wituschek, Simon and Ewenz, Lars and Kalich, Jan and Weiß, Deborah and Sadeghian, Behdad and Busch, Matthias and Krüger, Jan Tobias and Neuser, Moritz and Grydin, Olexandr and Böhnke, Max and Bielak, Christian-Roman and Troschitz, Juliane}}, issn = {{2666-3309}}, journal = {{Journal of Advanced Joining Processes}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{Clinching of Aluminum Materials – Methods for the Continuous Characterization of Process, Microstructure and Properties}}}, doi = {{10.1016/j.jajp.2022.100108}}, year = {{2022}}, } @inbook{29771, author = {{Grydin, Olexandr and Mortensen, Dag and Neuser, Moritz and Lindholm, Dag and Fjaer, Hallvard G. and Schaper, Mirko}}, booktitle = {{Light Metals 2022}}, isbn = {{9783030925284}}, issn = {{2367-1181}}, publisher = {{Springer International Publishing}}, title = {{{Numerical and Experimental Investigation of Heat Transfer in the Solidification-Deformation Zone During Twin-Roll Casting of Aluminum Strips}}}, doi = {{10.1007/978-3-030-92529-1_96}}, year = {{2022}}, } @book{65710, author = {{Stoppel, Hans-Jürgen and Griese, Birgit}}, isbn = {{9783662637432}}, issn = {{2626-613X}}, publisher = {{Springer Berlin Heidelberg}}, title = {{{Übungsbuch zur Linearen Algebra}}}, doi = {{10.1007/978-3-662-63744-9}}, year = {{2022}}, } @inproceedings{66909, author = {{Marker, Rabea and Kullmann, Harry and Zentarra, Dominik and Geist, Sabine and Lütje-Klose, Birgit}}, location = {{Otto-Friedrich-Universität Bamberg}}, title = {{{Schulbezogenes Zugehörigkeitsgefühl in inklusiven Lerngruppen: Vergleich der Labor-schule Bielefeld mit Vergleichsstichproben aus inklusiven Regelschulklassen und Ermittlung von Bedingungsfaktoren}}}, year = {{2022}}, } @article{34434, abstract = {{In timing chain drives, the chain is the critical component regarding the wear. Relative movements take place at the chain joint between pin and bush, which lead to wear of the chain joint due to friction and so to chain elongation. The chain joint is generally lubricated with oils, through which elastohydrodynamic processes can occur in the gap between the pin and the bush of the chain joint. A simulation model is developed here to examine these elastohydrodynamic processes considering a mass conserving cavitation model, the Newtonian flow behaviour of the lubricant and the structuring of the bush surface, whereby the real form of the bush is considered. MBS simulations are used to obtain realistic loads on the chain joint.}}, author = {{Simo Kamga, Lionel and Meffert, Dominik and Magyar, Balázs and Oehler, Manuel and Sauer, Bernd}}, issn = {{0301-679X}}, journal = {{Tribology International}}, keywords = {{EHL-simulation, Cavitation, Chain drives, Chain joint, Micro-structuring}}, pages = {{107564}}, title = {{{Simulative investigation of the influence of surface texturing on the elastohydrodynamic lubrication in chain joints}}}, doi = {{https://doi.org/10.1016/j.triboint.2022.107564}}, volume = {{171}}, year = {{2022}}, } @phdthesis{24760, abstract = {{Anwendungen von Laser-Sinter Bauteilen als Sichtteile sind aufgrund der vergleichsweise schlechten Oberflächenqualität sehr begrenzt. In dieser Arbeit werden dreidimensionale Kennwerte benutzt, um die Oberflächenqualität von Laser-Sinter Bauteiloberflächen und die Einflüsse aus unterschiedlichen Bereichen der gesamten Prozesskette zu evaluieren. Beispielsweise wurden objektive Kennwerte, mit deren Hilfe Orangenhaut zu identifizieren ist, und Prozessparameter, die diese deutlich vermindern, gefunden. Mittels Durchführung von haptischen Versuchen wurde das subjektive Empfinden ermittelt und konnten zu objektiven Kennwerten korreliert werden. Eine mikroskopische Betrachtung des flachen Oberflächenwinkels mit verschieden farbigen Pulvern zeigt neue Erkenntnisse zum Anschmelzvorgang von Partikeln an die Schmelze. Zur nachträglichen Glättung von Oberflächen wurden mechanische, chemische und optische Nachbehandlungsmethoden verwendet und deren Potential aufgezeigt. Eine abschließende neuartige Simulation der dreidimensionalen Topografie bildet die Grundlage für ein Programm zur automatischen und funktionsgerechten Orientierung von Bauteilen, welche am Beispiel eines realen Bauteils erfolgreich validiert wurde. Zusammengenommen zeigen die Ergebnisse, dass die richtige Wahl von Bauorientierung und Prozessparametern entscheidend für die Bauteilqualität ist und selbst eine aufwendige Nachbearbeitung eine ungeschickte Wahl derer nur schwerlich ausgleichen kann. }}, author = {{Delfs, Patrick}}, isbn = {{978-3-8440-7825-1}}, keywords = {{Additive Fertigung, Oberflächenqualität, 3D, Topografie, Simulation, PA12, Laser-Sintern, Rauheit}}, pages = {{126}}, publisher = {{Shaker Verlag GmbH}}, title = {{{Dreidimensionale Oberflächenanalyse und Topografie-Simulation additiv hergestellter Laser-Sinter Bauteile}}}, volume = {{22}}, year = {{2021}}, }