@article{42636, abstract = {{ Laser additive manufacturing processes are used for the production of highly complex geometric structures due to their high geometric freedom. Additive manufacturing processes, in particular powder-based selective laser melting, are used to produce metallic additive manufactured components for the automotive and aerospace industries. Different materials are often joined together to realize sustainable lightweight construction. The production of such mixed construction joints is often realized using mechanical joining technology (e.g. self-piercing riveting). However, there is currently very little experience with the mechanical joining of metallic additive manufacturing components. Furthermore, there is insufficient knowledge about the effects that occur during the mechanical joining of additive manufacturing components. In this article, a method is presented to investigate the joinability of additively manufactured components with conventionally manufactured components using a numerical simulation of the self-piercing riveting process. For this purpose, the additive manufacturing materials are characterized experimentally, the simulation model is configured, and the joining process with additive manufacturing materials is represented in the numerical simulation. Furthermore, the influence of the building direction on the mechanical properties is shown using miniature tensile specimens. Besides the configuration of the simulation model, the influence of heat treatment on the self-piercing riveting process is presented. }}, author = {{Heyser, Per and Petker, Rudolf 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 = {{{Development of a numerical simulation model for self-piercing riveting of additive manufactured AlSi10Mg}}}, doi = {{10.1177/14644207231158213}}, year = {{2023}}, } @inproceedings{31849, author = {{Hoffmann, Max and Biehler, Rolf}}, booktitle = {{Proceedings of the Fourth Conference of the International Network for Didactic Research in University Mathematics (INDRUM 2022, 19-22 October 2022)}}, editor = {{Trigueros, Marı́a and Barquero, Berta and Hochmuth, Reinhard and Peters, Jana}}, keywords = {{Teaching and learning of specific topics in university mathematics, Transition to, across and from university mathematics, Student Teachers, Geometry, Congruence, Double Discontinuity.}}, publisher = {{University of Hannover and INDRUM.}}, title = {{{Student Teachers ’ Knowledge of Congruence before a University Course on Geometry}}}, year = {{2023}}, } @inproceedings{43097, author = {{Florensa, Ignasio and Hoffmann, Max and Romo Vázquez, Avenilde and Zandieh, Michelle and Martínez-Planell, Rafael}}, booktitle = {{Proceedings of the Fourth Conference of the International Network for Didactic Research in University Mathematics (INDRUM 2022, 19-22 October 2022)}}, editor = {{Trigueros, Marı́a and Barquero, Berta and Hochmuth, Reinhard and Peters, Jana}}, title = {{{Innovations in university teaching based on mathematic education research}}}, year = {{2023}}, } @article{36983, abstract = {{AbstractThe use of structured measuring systems to prevent wall slip is a common approach to obtain absolute rheological values. Typically, only the minimum distance between the measuring surfaces is used for further calculation, implying that no flow occurs between the structural elements. But this assumption is misleading, and a gap correction is necessary. To determine the radius correction $$\Delta r$$ Δ r for specific geometries, we conducted investigations on three Newtonian fluids (two silicon oils and one suspension considered to be Newtonian in the relevant shear rate range). The results show that $$\Delta r$$ Δ r is not only shear- and material-independent, but geometry-dependent, providing a Newtonian flow behaviour in a similar viscosity range. Therefore, a correction value can be determined with only minute deviations in different Newtonian fluids. As the conducted laboratory measurements are very time-consuming and expensive, a CFD-approach with only very small deviations was additionally developed and compared for validation purposes. Therefore, simulation is an effective and resource-efficient alternative to the presented laboratory measurements to determine $$\Delta r$$ Δ r for the correction of structured coaxial geometries even for non-Newtonian fluids in the future.}}, author = {{Josch, Sebastian and Jesinghausen, Steffen and Dechert, Christopher and Schmid, Hans-Joachim}}, issn = {{0035-4511}}, journal = {{Rheologica Acta}}, keywords = {{rheology, rheometry, suspension, coaxial, correction}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Experimental and simulative determination and correction of the effective gap extension in structured coaxial measuring systems}}}, doi = {{10.1007/s00397-023-01383-2}}, year = {{2023}}, } @inproceedings{44181, author = {{Beule, Felix and Schmelzle, Lars and Teutenberg, Dominik and Possart, Gunnar and Meschut, Gerson and Mergheim, Julia}}, booktitle = {{23. Kolloquium: Gemeinsame Forschung in der Klebtechnik}}, location = {{Frankfurt}}, title = {{{Methodenentwicklung zur Simulation von hyperelastischen Klebverbindungen unter Crashbelastung}}}, year = {{2023}}, } @article{43034, abstract = {{Abstract The accessibility to rheological parameters for concrete is becoming more and more relevant. This is mainly related to the constantly emerging challenges, such as not only the development of high-strength concretes is progressing very fast but also the simulation of the flow behaviour is of high importance. The main problem, however, is that the rheological characterisation of fresh concrete is not possible via commercial rheometers. The so-called concrete rheometers provide valuable relative values for comparing different concretes, but they cannot measure absolute values. Therefore, we developed an adaptive coaxial concrete rheometer (ACCR) that allows the measurement of fresh concrete with particles up to d max = 5.5 mm {d}_{{\rm{\max }}}=5.5\hspace{.5em}{\rm{mm}} . The comparison of the ACCR with a commercial rheometer showed very good agreement for selected test materials (Newtonian fluid, shear thinning fluid, suspension, and yield stress fluid), so that self-compacting concrete was subsequently measured. Since these measurements showed a very high reproducibility, the rheological properties of the fresh concrete could be determined with high accuracy. The common flow models (Bingham (B), Herschel–Bulkley, modified Bingham (MB) models) were also tested for their applicability, with the Bingham and the modified Bingham model proving to be the best suitable ones.}}, author = {{Josch, Sebastian and Jesinghausen, Steffen and Schmid, Hans-Joachim}}, issn = {{1617-8106}}, journal = {{Applied Rheology}}, keywords = {{Condensed Matter Physics, General Materials Science}}, number = {{1}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{Development of an adaptive coaxial concrete rheometer and rheological characterisation of fresh concrete}}}, doi = {{10.1515/arh-2022-0140}}, volume = {{33}}, year = {{2023}}, } @inproceedings{43044, abstract = {{Abstract. The combination of incremental sheet metal forming and high-speed forming offers new possibilities for flexible forming processes in the production of large sheet metal components of increased complexity with relatively low forming energies. In this paper, the general feasibility and process differences between the pulse-driven high-speed forming technologies of electrohydraulic and electromagnetic forming were investigated. An example component made of EN AW 6016 aluminum sheet metal was thus formed incrementally by both processes and the forming result evaluated by an optical 3D measurement system. For this purpose, a forming strategy for electromagnetic incremental forming (EMIF) was developed, tested and adapted to the electrohydraulic incremental forming process (EHIF). The discharge energy, the tool displacement and the pressure field of the forming zone were determined as relevant parameters for the definition of an adequate tool path strategy. It was found that the EHIF process is less affected by larger distances between the tool and the blank, while this is a critical variable for force application to the component during EMIF. On the other hand, the more uniform pressure distribution of the EMIF process is advantageous for forming large steady component areas. }}, author = {{Holzmüller, Maik and Linnemann, Maik and Homberg, Werner and Psyk, Verena and Kräusel, Verena and Kroos, Janika}}, booktitle = {{Materials Research Proceedings}}, issn = {{2474-395X}}, keywords = {{Incremental Sheet Forming, Aluminium, High-Speed Forming}}, location = {{Nürnberg}}, pages = {{11--18}}, publisher = {{Materials Research Forum LLC}}, title = {{{Proof of concept for incremental sheet metal forming by means of electromagnetic and electrohydraulic high-speed forming}}}, doi = {{10.21741/9781644902417-2}}, volume = {{25}}, year = {{2023}}, } @article{44382, abstract = {{The success of engineering complex technical systems is determined by meeting customer requirements and institutional regulations. One example relevant to the automobile industry is the United Nations Economic Commission of Europe (UN ECE), which specifies the homologation of automobile series and requires proof of traceability. The required traceability can be achieved by modeling system artifacts and their relations in a consistent, seamless model—an effect-chain model. Currently, no in-depth methodology exists to support engineers in developing certification-compliant effect-chain models. For this purpose, a new methodology for certification-compliant effect-chain modeling was developed, which includes extensions of an existing method, suitable models, and tools to support engineers in the modeling process. For evaluation purposes, applicability is proven based on the experience of more than 300 workshops at an automotive OEM and an automotive supplier. The following case example is chosen to demonstrate applicability: the development of a window lifter that has to meet the demands of UN ECE Regulations R156 and R21. Results indicate multiple benefits in supporting engineers with the certification-compliant modeling of effect chains. Three benefits are goal-oriented modeling to reduce the necessary modeling capacity, increasing model quality by applying information quality criteria, and the potential to reduce costs through automatable effect-chain analyses for technical changes. Further, companies in the automotive and other industries will benefit from increased modeling capabilities that can be used for architecture modeling and to comply with other regulations such as ASPICE or ISO 26262.}}, author = {{Gräßler, Iris and Wiechel, Dominik and Koch, Anna-Sophie and Sturm, Tim and Markfelder, Thomas}}, issn = {{2079-8954}}, journal = {{Systems}}, keywords = {{Information Systems and Management, Computer Networks and Communications, Modeling and Simulation, Control and Systems Engineering, Software}}, number = {{3}}, publisher = {{MDPI AG}}, title = {{{Methodology for Certification-Compliant Effect-Chain Modeling}}}, doi = {{10.3390/systems11030154}}, volume = {{11}}, year = {{2023}}, } @inproceedings{44390, abstract = {{The development of autonomous vehicles and their introduction in urban traffic offer many opportunities for traffic improvements. In this paper, an approach for a future traffic control system for mixed autonomy traffic environments is presented. Furthermore, a simulation framework based on the city of Paderborn is introduced to enable the development and examination of such a system. This encompasses multiple elements including the road network itself, traffic lights, sensors as well as methods to analyse the topology of the network. Furthermore, a procedure for traffic demand generation and routing is presented based on statistical data of the city and traffic data obtained by measurements. The resulting model can receive and apply the generated control inputs and in turn generates simulated sensor data for the control system based on the current system state.}}, author = {{Link, Christopher and Malena, Kevin and Gausemeier, Sandra and Trächtler, Ansgar}}, booktitle = {{Proceedings of the 9th International Conference on Vehicle Technology and Intelligent Transport Systems}}, isbn = {{978-989-758-652-1}}, keywords = {{Traffic Simulation, Traffic Control, Car2X, Mixed Autonomy, Autonomous Vehicles, SUMO, Sensor Simulation, Traffic Demand Generation, Routing, Traffic Lights, Graph Analysis, Traffic Observer}}, location = {{Prague, Czech Republic}}, publisher = {{SCITEPRESS - Science and Technology Publications}}, title = {{{Simulation Environment for Traffic Control Systems Targeting Mixed Autonomy Traffic Scenarios}}}, doi = {{10.5220/0011987600003479}}, year = {{2023}}, } @article{44477, author = {{Küster, Christine and Klünder, Nina and Wagenknecht, Inga}}, issn = {{2626-0913}}, journal = {{Hauswirtschaft und Wissenschaft}}, pages = {{1--12}}, publisher = {{Deutsche Gesellschaft für Hauswirtschaft e.V.}}, title = {{{Haushaltswissenschaft – Eine Diskussionsgrundlage}}}, doi = {{ 10.23782/HUW_09_2023}}, volume = {{71}}, year = {{2023}}, } @book{44524, editor = {{Meier-Gräwe, Uta and Praetorius, Ina and Tecklenburg, Feline}}, isbn = {{9783847425922}}, pages = {{307}}, publisher = {{Verlag Barbara Budrich}}, title = {{{Wirtschaft neu ausrichten. Care-Initiativen in Deutschland, Österreich und der Schweiz.}}}, year = {{2023}}, } @inproceedings{44228, author = {{Salten, Alexander Heinrich Johannes and Al Trjman, Mohamad and Meschut, Gerson and Kenig, Eugeny Y.}}, location = {{Paderborn}}, title = {{{Simulation des „viscous fingering“ Effektes in Klebverbindungen}}}, year = {{2023}}, } @inproceedings{44227, author = {{Al Trjman, Mohamad and Meschut, Gerson and Salten, Alexander Heinrich Johannes and Kenig, Eugeny Y.}}, location = {{Frankfurt am Main}}, title = {{{Methodenentwicklung zur Simulation des Viscous Fingering in Klebverbindungen von stahlintensiven Mischbaustrukturen}}}, year = {{2023}}, } @article{41492, abstract = {{The current investigation shows the feasibility of 316L steel powder production via three different argon gas atomisation routes (closed coupled atomisation, free fall atomisation with and without hot gas), along with subsequent sample production by laser powder bed fusion (PBF-LB). Here, a mixture of pure Fe and atomised 316L steel powder is used for PBF-LB to induce a chemical composition gradient in the microstructure. Optical microscopy and μ-CT investigations proved that the samples processed by PBF-LB exhibit very little porosity. Combined EBSD-EDS measurements show the chemical composition gradient leading to the formation of a local fcc-structure. Upon heat treatment (1100 °C, 14 h), the chemical composition is homogeneous throughout the microstructure. A moderate decrease (1060 to 985 MPa) in the sample’s ultimate tensile strength (UTS) is observed after heat treatment. However, the total elongation of the as-built and heat-treated samples remains the same (≈22%). Similarly, a slight decrease in the hardness from 341 to 307 HV1 is observed upon heat treatment.}}, author = {{Pramanik, Sudipta and Andreiev, Anatolii and Hoyer, Kay-Peter and Krüger, Jan Tobias and Hengsbach, Florian and Kircheis, Alexander and Zhao, Weiyu and Fischer-Bühner, Jörg and Schaper, Mirko}}, issn = {{2674-0516}}, journal = {{Powders}}, number = {{1}}, pages = {{59--74}}, publisher = {{MDPI AG}}, title = {{{Powder Production via Atomisation and Subsequent Laser Powder Bed Fusion Processing of Fe+316L Steel Hybrid Alloy}}}, doi = {{10.3390/powders2010005}}, volume = {{2}}, year = {{2023}}, } @article{43441, abstract = {{This paper reveals the 3D character of the intermetallic layer at the aluminum–steel interface which pops up above the original sample surface during annealing. Popping out of the intermetallics was proven using atomic force microscopy. The phase expands out of the plane due to the exothermic formation of the Al5Fe2 phase and the feasibility of surface diffusion. Milling by a focused ion beam enabled the comparison of the chemical composition of the surface layer with the bulk interface, showing no difference. The growth direction is both towards aluminum and steel — the main diffusion flux is from aluminum towards steel, and the new intermetallic phase emerges at the steel side. The shortage of Al atoms causes a shift of the intermetallic as a whole towards aluminum.}}, author = {{Šlapáková, Michaela and Kihoulou, Barbora and Veselý, Jozef and Minárik, Peter and Fekete, Klaudia and Knapek, Michal and Králík, Rostislav and Grydin, Olexandr and Stolbchenko, Mykhailo and Schaper, Mirko}}, issn = {{0042-207X}}, journal = {{Vacuum}}, keywords = {{Al-steel clad, twin-roll casting, 3D characterization, atomic force microscopy, diffusion direction, surface growth}}, publisher = {{Elsevier BV}}, title = {{{3D-structure of intermetallic interface layer in Al–steel clad material}}}, doi = {{10.1016/j.vacuum.2023.112043}}, volume = {{212}}, year = {{2023}}, } @article{44078, author = {{Andreiev, Anatolii and Hoyer, Kay-Peter and Hengsbach, Florian and Haase, Michael and Tasche, Lennart and Duschik, Kristina and Schaper, Mirko}}, issn = {{0924-0136}}, journal = {{Journal of Materials Processing Technology}}, keywords = {{Industrial and Manufacturing Engineering, Metals and Alloys, Computer Science Applications, Modeling and Simulation, Ceramics and Composites}}, publisher = {{Elsevier BV}}, title = {{{Powder bed fusion of soft-magnetic iron-based alloys with high silicon content}}}, doi = {{10.1016/j.jmatprotec.2023.117991}}, volume = {{317}}, year = {{2023}}, } @inbook{45606, author = {{Freymuth, Nina}}, booktitle = {{Diskriminierungsprozesse und Teilhabeperspektiven - Herausforderungen für die Praxis der Inklusion. Ausgewählte Master-Thesen 2018-2022 des Masterstudiengangs "Soziale Inklusion: Gesundheit und Bildung" der Evangelischen Hochschule Rheinland-Westfalen-Lippe}}, editor = {{Balz, HHans-Jürgen and Huneke, Annika and Kuhlmann, Carola and Römisch, Kathrin}}, pages = {{22--33}}, title = {{{Alternative für alle? Inklusionsspezifische Analyse der AfD und ihrer Wähler*innen}}}, year = {{2023}}, } @article{45757, abstract = {{AbstractThree prominent low order implicit time integration schemes are the first order implicit Euler-method, the second order trapezoidal rule and the second order Ellsiepen method. Its advantages are stability and comparatively low computational cost, however, they require the solution of a nonlinear system of equations. This paper presents a general approach for the construction of third order Runge–Kutta methods by embedding the above mentioned implicit schemes into the class of ELDIRK-methods. These will be defined to have an Explicit Last stage in the general Butcher array of Diagonal Implicit Runge–Kutta (DIRK) methods, with the consequence, that no additional system of equations must be solved. The main results—valid also for non-linear ordinary differential equations—are as follows: Two extra function calculations are required in order to embed the implicit Euler-method and one extra function calculation is required for the trapezoidal-rule and the Ellsiepen method, in order to obtain the third order properties, respectively. Two numerical examples are concerned with a parachute with viscous damping and a two-dimensional laser beam simulation. Here, we verify the higher order convergence behaviours of the proposed new ELDIRK-methods, and its successful performances for asymptotically exact global error estimation of so-called reversed embedded RK-method are shown. }}, author = {{Mahnken, Rolf}}, issn = {{0178-7675}}, journal = {{Computational Mechanics}}, keywords = {{Applied Mathematics, Computational Mathematics, Computational Theory and Mathematics, Mechanical Engineering, Ocean Engineering, Computational Mechanics}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Derivation of third order Runge–Kutta methods (ELDIRK) by embedding of lower order implicit time integration schemes for local and global error estimation}}}, doi = {{10.1007/s00466-023-02347-2}}, year = {{2023}}, } @article{45807, abstract = {{Abstract Background Occupational health interventions for leaders are underrepresented in small and medium-sized enterprises (SMEs). When creating and developing effective occupational health interventions, identification of the specific needs of the target group is regarded as an essential step before planning an intervention. Therefore, the aim of this study was (1) to examine the subjectively experienced work-related stressors of leaders in small and medium-sized IT and technological services enterprises, (2) to explore coping behaviors leaders use to deal with the experienced work-related stressors, (3) to investigate resources supporting the coping process and (4) to identify potentially self-perceived consequences resulting from the experienced stressors. Methods Ten semi-structured interviews with leaders in small and medium-sized IT and technological services enterprises were conducted. The interviews were transcribed and analyzed with content-structuring qualitative content analysis in accordance to Kuckartz. Results Leaders in small and medium-sized IT and technological services enterprises experience various stressors caused by work organization as well as industry-related stressors and other work-related stressors. To address the experienced stressors, leaders apply problem focused coping behaviors (e.g. performing changes on structural and personal level), emotional focused coping behaviors (e.g. balancing activities, cognitive restructuring) as well as the utilization of social support. Helpful resources for the coping process include organizational, social and personal resources. As a result of the experienced work-related stressors, interviewees stated to experience different health impairments, negative effects on work quality as well as neglect of leisure activities and lack of time for family and friends. Conclusion The identified experienced work-related stressors, applied coping behaviors, utilized resources and emerging consequences underpin the urgent need for the development and performance of health-oriented leadership interventions for leaders in small and medium- sized IT and technological services. The results of this study can be used when designing a target-oriented intervention for the examined target group. }}, author = {{Dannheim, Indra and Buyken, Anette and Kroke, Anja}}, issn = {{1471-2458}}, journal = {{BMC Public Health}}, keywords = {{Public Health, Environmental and Occupational Health}}, number = {{1}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Work-related stressors and coping behaviors among leaders in small and medium-sized IT and technological services enterprises}}}, doi = {{10.1186/s12889-023-15581-3}}, volume = {{23}}, year = {{2023}}, } @article{45806, abstract = {{Abstract Objective: To systematically review the impact of choice architecture interventions (CAI) on the food choice of healthy adolescents in a secondary school setting. Factors potentially contributing to the effectiveness of CAI types and numbers implemented and its long-term success were examined. Design: PUBMED and Web of Science were systematically searched in October 2021. Publications were included following predefined inclusion criteria and grouped according to number and duration of implemented interventions. Intervention impact was determined by systematic description of the reported quantitative changes in food choice and/or consumption. Intervention types were compared with regards to food selection and sustained effects either during or following the intervention. Setting: CAI on food choice of healthy adolescents in secondary schools. Participants: Not applicable Results: Fourteen studies were included; four randomized controlled trials and five each of controlled or uncontrolled pre-post design, respectively. Four studies implemented a single CAI type, with ten implementing > 1. Three studies investigated CAI effects over the course of a school year either by continuous or repeated data collection, while ten studies’ schools were visited on selected days during intervention. Twelve studies reported desired changes in overall food selection, yet effects were not always significant, and appeared less conclusive for longer term studies. Conclusions: This review found promising evidence that CAI can be effective in encouraging favorable food choices in healthy adolescents in a secondary school setting. However, further studies designed to evaluate complex interventions are needed. }}, author = {{Schulte, Eva A. and Winkler, Gertrud and Brombach, Christine and Buyken, Anette}}, issn = {{1368-9800}}, journal = {{Public Health Nutrition}}, keywords = {{Public Health, Environmental and Occupational Health, Nutrition and Dietetics, Medicine (miscellaneous)}}, pages = {{1--23}}, publisher = {{Cambridge University Press (CUP)}}, title = {{{Choice architecture interventions promoting sustained healthier food choice and consumption by students in a secondary school setting: A systematic review of intervention studies}}}, doi = {{10.1017/s1368980023001118}}, year = {{2023}}, }