@article{34832, author = {{Hanusch, Maximilian}}, journal = {{Annals of Global Analysis and Geometry}}, keywords = {{Lax equation, generalized Baker-Campbell-Dynkin-Hausdorff formula, regularity of Lie groups}}, number = {{21}}, title = {{{The Lax Equation and Weak Regularity of Asymptotic Estimate Lie Groups}}}, doi = {{10.1007/s10455-023-09888-y}}, volume = {{63}}, year = {{2023}}, } @article{39057, author = {{Wippermann, Jan and Meschut, Gerson and Koschukow, Wikentji and Liebsch, Alexander and Gude, Maik and Minch, Steven and Kolbe, Björn}}, issn = {{0043-2288}}, journal = {{Welding in the World}}, keywords = {{Metals and Alloys, Mechanical Engineering, Mechanics of Materials}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Thermal influence of resistance spot welding on a nearby overmolded thermoplastic–metal joint}}}, doi = {{10.1007/s40194-023-01465-y}}, year = {{2023}}, } @article{43457, abstract = {{The production of hydrogen and the utilization of biomass for sustainable concepts of energy conversion and storage require gas sensors that discriminate between hydrogen (H2) and carbon monoxide (CO). Mesoporous copper–ceria (Cu–CeO2) materials with large specific surface areas and uniform porosity are prepared by nanocasting, and their textural properties are characterized by N2 physisorption, powder XRD, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The oxidation states of copper (Cu+, Cu2+) and cerium (Ce3+, Ce4+) are investigated by XPS. The materials are used as resistive gas sensors for H2 and CO. The sensors show a stronger response to CO than to H2 and low cross-sensitivity to humidity. Copper turns out to be a necessary component; copper-free ceria materials prepared by the same method show only poor sensing performance. By measuring both gases (CO and H2) simultaneously, it is shown that this behavior can be utilized for selective sensing of CO in the presence of H2.}}, author = {{Baier, Dominik and Priamushko, Tatiana and Weinberger, Christian and Kleitz, Freddy and Tiemann, Michael}}, issn = {{2379-3694}}, journal = {{ACS Sensors}}, keywords = {{Fluid Flow and Transfer Processes, Process Chemistry and Technology, Instrumentation, Bioengineering}}, number = {{4}}, pages = {{1616 -- 1623}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Selective Discrimination between CO and H2 with Copper–Ceria-Resistive Gas Sensors}}}, doi = {{10.1021/acssensors.2c02739}}, volume = {{8}}, year = {{2023}}, } @article{46018, author = {{Su, Ran and Zhang, Jiahui and Wong, Vienna and Zhang, Dawei and Yang, Yong and Luo, Zheng‐Dong and Wang, Xiaojing and Wen, Hui and Liu, Yang and Seidel, Jan and Yang, Xiaolong and Pan, Ying and Li, Fa‐tang}}, issn = {{0935-9648}}, journal = {{Advanced Materials}}, keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}}, publisher = {{Wiley}}, title = {{{Engineering Sub‐Nanometer Hafnia‐Based Ferroelectric to Break The Scaling Relation for High‐Efficiency Piezocatalytic Water Splitting}}}, doi = {{10.1002/adma.202303018}}, year = {{2023}}, } @article{46483, abstract = {{The demands on joining technology are constantly increasing due to the consistent lightweight construction and the associated increasing material mix. To meet these requirements, the adaptability of the joining processes must be improved to be able to process different material combinations and to react to challenges caused by deviations in the process chain. One example of a highly adaptable process due to the two-step process sequence is thermomechanical joining with Friction Spun Joint Connectors (FSJCs) that can be individually adapted to the joint. In this paper, the potentials of the adaption in the two-stage joining process with aluminium auxiliary joining elements are investigated. To this end, it is first investigated whether a thermomechanical forming process can be used to achieve a uniform and controlled manufacturing regarding the process variable of the temperature as well as the geometry of the FSJC. Based on the successful proof of the high and good repeatability in the FSJC manufacturing, possibilities, and potentials for the targeted influencing of the process and FSJC geometry are shown, based on an extensive variation of the process input variables (delivery condition and thus mechanical properties of the raw parts as well as the process parameters of rotational speed and feed rate). Here it can be shown that above all, the feed rate of the final forming process has the strongest influence on the process and thus also offers the strongest possibilities for influencing it.}}, author = {{Borgert, Thomas and Henke, Maximilian and Homberg, Werner}}, issn = {{2504-4494}}, journal = {{Journal of Manufacturing and Materials Processing}}, keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering, Mechanics of Materials}}, number = {{4}}, publisher = {{MDPI AG}}, title = {{{Investigations on the Influences of the Thermomechanical Manufacturing of Aluminium Auxiliary Joining Elements}}}, doi = {{10.3390/jmmp7040147}}, volume = {{7}}, year = {{2023}}, } @article{47122, abstract = {{AbstractFeCo alloys are important materials used in pumps and motors in the offshore oil and gas drilling industry. These alloys are subjected to marine environments with a high NaCl concentration, therefore, corrosion and catastrophic failure are anticipated. So, the surface dissolution of additively manufactured FeCo samples is investigated in a quasi-in situ manner, in particular, the pitting corrosion in 5.0 wt pct NaCl solution. The local dissolution of the same sample region is monitored after 24, 72, and 168 hours. Here, the formation of rectangular and circular pits of ultra-fine dimensions (less than 0.5 µm) is observed with increasing immersion time. In addition, the formation of a corrosion-inhibiting surface layer is detected on the sample surface. Surface dissolution leads to a change in the surface structure, however, no change in grain shape or grain size is noticed. The surface topography after local dissolution is correlated to the grain orientation. Quasi-in situ analysis shows the preferential dissolution of high-angle grain boundaries (HAGBs) leading to a change in the fraction of HAGBs and low-angle grain boundaries fraction (LAGBs). For the FeCo sample, a potentiodynamic polarisation test reveals a corrosion potential (Ecorr) of − 0.475 V referred to the standard hydrogen electrode (SHE) and a corrosion exchange current density (icorr) of 0.0848 A/m2. Furthermore, quasi-in situ experiments showed that grains oriented along certain crystallographic directions are corroding more compared to other grains leading to a significant decrease in the local surface height. Grains with a plane normal close to the $$\langle {1}00\rangle$$ ⟨ 100 ⟩ direction reveal lower surface dissolution and higher corrosion resistance, whereas planes normal close to the $$\langle {11}0\rangle$$ ⟨ 110 ⟩ direction and the $$\langle {111}\rangle$$ ⟨ 111 ⟩ direction exhibit a higher surface dissolution.}}, author = {{Pramanik, Sudipta and Krüger, Jan Tobias and Schaper, Mirko and Hoyer, Kay-Peter}}, issn = {{1073-5623}}, journal = {{Metallurgical and Materials Transactions A}}, keywords = {{Metals and Alloys, Mechanics of Materials, Condensed Matter Physics}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Quasi-In Situ Localized Corrosion of an Additively Manufactured FeCo Alloy in 5 Wt Pct NaCl Solution}}}, doi = {{10.1007/s11661-023-07186-7}}, year = {{2023}}, } @article{47155, abstract = {{»Über Geld spricht man nicht.« Diese Benimmregel erweist sich beim Blick in die Ver- gangenheit als Illusion. Keineswegs war Geld grundsätzlich ein Tabuthema zwischen- menschlicher Kommunikation. Ganz im Gegenteil: Mit dem Reden über Geld wird dieses mit Bedeutung aufgeladen. Die Autor*innen dieses Themenheftes untersuch en Gelddis- kurse und die Zuschreibungen von Bedeutung an Geld in der internationalen Geschichte.}}, author = {{Schönhärl, Korinna and Schotters, Frederike and Thiemeyer, Guido}}, journal = {{Werkstatt Geschichte}}, keywords = {{Financial History, Discourse Analysis, History of Money}}, title = {{{Editorial}}}, volume = {{88}}, year = {{2023}}, } @misc{47154, abstract = {{»Über Geld spricht man nicht.« Diese Benimmregel erweist sich beim Blick in die Vergangenheit als Illusion. Keineswegs war Geld grundsätzlich ein Tabuthema zwischenmenschlicher Kommunikation. Ganz im Gegenteil: Mit dem Reden über Geld wird dieses mit Bedeutung aufgeladen. Die Autor*innen dieses Themenheftes untersuchen Gelddiskurse und die Zuschreibungen von Bedeutung an Geld in der internationalen Geschichte.}}, booktitle = {{Werkstatt Geschichte}}, editor = {{Schönhärl, Korinna and Schotters, Frederike and Thiemeyer, Guido}}, keywords = {{Financial History, Discourse Analysis, History of Money}}, title = {{{Reden über Geld}}}, volume = {{88}}, year = {{2023}}, } @article{46494, abstract = {{To improve the mechanical performance and to address current shortcomings of adhesive bonds such as bond degradation due to aging, a pulsed laser surface pretreatment of the metal surfaces of aluminum AW 6082-T6 joints with epoxy adhesive E320 is investigated. The surface treatment of the specimens resulted in increased single-lap shear (SLS) strengths before and after hydrothermal aging in 80°C hot water compared to nonpretreated reference specimens. In order to reveal the correlations of laser parameters, resulting surface morphologies and the SLS strength, differently laser pretreated surfaces were characterized at the micro- and nanoscale using optical and scanning electron microscopies. The surface enlargement was quantified with a digital image analysis of cross-sections prepared from the joint interfaces. An analysis of variances (ANOVA) of the SLS results indicated that the laser parameters power and pulse frequency were most critical for obtaining high SLS strengths. Pretreated joint surfaces with a high micro- and nano-surface enlargement and deep solidification structures provide high SLS strengths of up to 50 MPa and almost negligible aging losses of merely 4%. Undercut structures on the pretreated surfaces were found to be beneficial for the mechanical and aging properties when only limited micro- and nanostructuring was applied.}}, author = {{Freund, Jonathan and Löbbecke, Miriam and Delp, Alexander and Walther, Frank and Wu, Shuang and Tröster, Thomas and Haubrich, Jan}}, issn = {{0021-8464}}, journal = {{The Journal of Adhesion}}, keywords = {{Materials Chemistry, Surfaces, Coatings and Films, Surfaces and Interfaces, Mechanics of Materials, General Chemistry}}, pages = {{1--31}}, publisher = {{Informa UK Limited}}, title = {{{Relationship between laser-generated micro- and nanostructures and the long-term stability of bonded epoxy-aluminum joints}}}, doi = {{10.1080/00218464.2023.2223475}}, year = {{2023}}, } @article{46495, abstract = {{A parameter investigation for manufacturing a hybrid system through the prepreg pressing process was carried out within the scope of this work to achieve optimal adhesion properties. The hybrid specimen comprises an aluminium sheet of alloy EN AW 6082 in T6 condition and a thermoset Carbon Fibre Reinforced Plastics prepreg. The prepreg pressing process allows the curing reaction of epoxy resin and the joining process to occur simultaneously to avoid an additional bonding process step. The surface of the aluminium sheet was pretreated in advance using a pulsed Nd:YAG laser to enhance the bonding properties. In the first step, the shear edge tests investigated the adhesion properties achieved with different consolidation (temperature, time and pressure) and laser parameters. Then, 3-point bending tests were carried out to investigate the influence of the consolidation parameters on the mechanical properties of the Carbon Fibre Reinforced Plastics-laminate. In this way, the optimal parameter sets for manufacturing hybrid structures were determined.}}, author = {{Wu, Shuang and Delp, Alexander and Freund, Jonathan and Walther, Frank and Haubrich, Jan and Löbbecke, Miriam and Tröster, Thomas}}, issn = {{0021-8464}}, journal = {{The Journal of Adhesion}}, keywords = {{Materials Chemistry, Surfaces, Coatings and Films, Surfaces and Interfaces, Mechanics of Materials, General Chemistry}}, pages = {{1--29}}, publisher = {{Informa UK Limited}}, title = {{{Adhesion properties of the hybrid system made of laser-structured aluminium EN AW 6082 and CFRP by co-bonding-pressing process}}}, doi = {{10.1080/00218464.2023.2245758}}, year = {{2023}}, } @article{56097, abstract = {{We contrast different gradient-enhancements for plasticity-damage material models in the logarithmic strain space and compare them to reference models based on multiplicative plasticity. The models being compared include plasticity - gradient-damage, where the gradient-enhancement is applied on the local damage variable, and gradient-plasticity - damage with a gradient-enhanced plastic hardening variable. Thereby, gradient-plasticity proved to be able to simultaneously regularise plastic and ductile (plasticity-driven) damage localisation as confirmed by numerical localisation analyses. This appears to be especially advantageous for logarithmic strain space plasticity-damage, because of the observed plastic localisation even for the case of plasticity with hardening. Even though gradient-plasticity appears to be numerically more demanding, two numerical examples indicate a good robustness and mesh objectivity in the softening regime. Moreover, the internal length for plasticity is able to adjust the damage zone width, similarly to gradient-damage, however ensuring a priori that damage takes place exclusively inside the plastic zone.}}, author = {{Friedlein, Johannes and Mergheim, Julia and Steinmann, Paul}}, issn = {{0997-7538}}, journal = {{European Journal of Mechanics - A/Solids}}, keywords = {{Finite plasticity, Logarithmic strain space, Ductile damage, Gradient-enhancement, Gradient-plasticity, Gradient-damage, Loss of ellipticity}}, publisher = {{Elsevier BV}}, title = {{{Efficient gradient enhancements for plasticity with ductile damage in the logarithmic strain space}}}, doi = {{10.1016/j.euromechsol.2023.104946}}, volume = {{99}}, year = {{2023}}, } @article{48584, abstract = {{The sustainability of the manufacturing industry is of special importance to increase the protection of the environment. The production of fasteners like self-piercing rivets, however, is costly, time-consuming and energy-intensive. The heat treatment and the coating, which are mandatory in conventional self-piercing rivets to achieve adequate strength, ductility and corrosion resistance, are especially crucial in this respect. Within this paper, an approach for an increase in the sustainability in fastener production is presented. The use of alternative, high strain hardening stainless steels as rivet material enables a shortening of the process chain, because post treatment of the rivets after they are formed can be omitted. As the change in rivet material and processing causes some issues along the process chain, the focus of this paper is on the holistic evaluation of the challenges within the forming of high strain hardening steel and the impact of the changed rivet properties on the joining result.}}, author = {{Uhe, Benedikt and Kuball, Clara-Maria and Merklein, Marion and Meschut, Gerson}}, issn = {{2504-4494}}, journal = {{Journal of Manufacturing and Materials Processing}}, keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering, Mechanics of Materials}}, number = {{6}}, publisher = {{MDPI AG}}, title = {{{Increased Sustainability in Fastener Production with the Example of Self-Piercing Rivets}}}, doi = {{10.3390/jmmp7060193}}, volume = {{7}}, year = {{2023}}, } @article{48603, abstract = {{AbstractToday, a major technological trend is the increasing focus on the person: technical systems personalize, customize, and tailor to the person in both beneficial and troubling ways. This trend has moved beyond the realm of commerce and has become a matter of public governance, where systems for citizen risk scoring, predictive policing, and social credit scores proliferate. What these systems have in common is that they may target the person and her ethical and political dispositions, her virtues. Virtue ethics is the most appropriate approach for evaluating the impacts of these new systems, which has translated in a revival of talk about virtue in technology ethics. Yet, the focus on individual dispositions has rightly been criticized for lacking a concern with the political collective and institutional structures. This paper advocates a new direction of research into civic virtue, which is situated in between personal dispositions and structures of governance. First, it surveys the discourse on virtue ethics of technology, emphasizing its neglect of the political dimension of impacts of emerging technologies. Second, it presents a pluralist conception of civic virtue that enables us to scrutinize the impact of technology on civic virtue on three different levels of reciprocal reputation building, the cultivation of internal goods, and excellence in the public sphere. Third, it illustrates the benefits of this conceptions by discussing some paradigmatic examples of emerging technologies that aim to cultivate civic virtue.}}, author = {{Reijers, Wessel}}, issn = {{2210-5433}}, journal = {{Philosophy & Technology}}, keywords = {{History and Philosophy of Science, Philosophy}}, number = {{4}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Technology and Civic Virtue}}}, doi = {{10.1007/s13347-023-00669-w}}, volume = {{36}}, year = {{2023}}, } @article{29809, author = {{Reitz, A. and Grydin, O. and Schaper, M.}}, issn = {{0921-5093}}, journal = {{Materials Science and Engineering: A}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Condensed Matter Physics, General Materials Science}}, publisher = {{Elsevier BV}}, title = {{{Influence of thermomechanical processing on the microstructural and mechanical properties of steel 22MnB5}}}, doi = {{10.1016/j.msea.2022.142780}}, volume = {{838}}, year = {{2022}}, } @book{30291, abstract = {{The volume comprises a variety of research approaches that seek to explore and understand employees’ learning and development through and for work. Working life reveals challenges through technological, economic and societal development that can only rudimentarily be addressed by formal education and training. Workplace learning becomes more and more important for employees and enterprises to successfully cope with these challenges. Workplace learning is a steadily growing field of educational research but it lacks so far a scholastic canon – there is rather a diversity of research approaches. This volume reflects this diversity by bringing together researchers from different countries and different theoretical backgrounds, presenting their current research on topics that all are relevant for understanding presages, processes and outcomes of workplace learning. Hence, this volume is of relevance for researchers as well as practitioners in the field and policy makers.}}, editor = {{Harteis, Christian and Gijbels, David and Kyndt, Eva}}, isbn = {{9783030895815}}, issn = {{2210-5549}}, keywords = {{new generation of researchersthe team level of workplace learningindividual level of workplace learningorganizational level of workplace learningsocietal level of workplace learninginterdependent cross-level research approachesWork AgencyWork-life perspectivesTeam learningTeam climateSocial influences on team learningKnowledge construction in teamsLearning cultureAcknowledgement of competencesTechnology and professional learningCreation of a learning eco-systemDiversity as a challenge for organisationsHigher education as preparation for WPLSocial support in networks and professional learningvocational and professional education}}, publisher = {{Springer International Publishing}}, title = {{{Research Approaches on Workplace Learning}}}, doi = {{10.1007/978-3-030-89582-2}}, year = {{2022}}, } @inbook{30290, abstract = {{The article explores the particular quality of changes introduced through the latest wave of digital transformation of workplaces. It has effects on workflow processes, on distribution of work and tasks, and the mode of distributing working tasks, e.g. through cyber-physical systems. Hence, the changes in work are manifold and require changes in vocational education and training as well as in workplace learning. These changes reveal new challenges for research on workplace learning. Finally, conclusions for future workplace learning research will be developed.}}, author = {{Harteis, Christian}}, booktitle = {{Research Approaches on Workplace Learning}}, isbn = {{9783030895815}}, issn = {{2210-5549}}, keywords = {{Digitalisation Self organisation Distribution of labour Automation}}, publisher = {{Springer International Publishing}}, title = {{{Research on Workplace Learning in Times of Digitalisation}}}, doi = {{10.1007/978-3-030-89582-2_19}}, year = {{2022}}, } @article{30743, author = {{Riedl, Thomas and Kunnathully, Vinay S. and Trapp, Alexander and Langer, Timo and Reuter, Dirk and Lindner, Jörg K. N.}}, issn = {{2196-7350}}, journal = {{Advanced Materials Interfaces}}, keywords = {{Mechanical Engineering, Mechanics of Materials}}, publisher = {{Wiley}}, title = {{{Size‐Dependent Strain Relaxation in InAs Quantum Dots on Top of GaAs(111)A Nanopillars}}}, doi = {{10.1002/admi.202102159}}, year = {{2022}}, } @article{29806, author = {{Huang, Jingyuan and Voigt, Markus and Wackenrohr, Steffen and Ebbert, Christoph and Keller, Adrian and Maier, Hans Jürgen and Grundmeier, Guido}}, issn = {{0947-5117}}, journal = {{Materials and Corrosion}}, keywords = {{Materials Chemistry, Metals and Alloys, Surfaces, Coatings and Films, Mechanical Engineering, Mechanics of Materials, Environmental Chemistry, Materials Chemistry, Metals and Alloys, Surfaces, Coatings and Films, Mechanical Engineering, Mechanics of Materials, Environmental Chemistry, Materials Chemistry, Metals and Alloys, Surfaces, Coatings and Films, Mechanical Engineering, Mechanics of Materials, Environmental Chemistry}}, pages = {{1034}}, publisher = {{Wiley}}, title = {{{Influence of hydrogel coatings on corrosion and fatigue of iron in simulated body fluid}}}, doi = {{10.1002/maco.202112841}}, volume = {{73}}, year = {{2022}}, } @article{34223, abstract = {{In this study, quasi-unidirectional continuous fiber reinforced thermoplastics (CFRTs) are joined with metal sheets via cold formed cylindrical, elliptical and polygonal pin structures which are directly pressed into the CFRT component after local infrared heating. In comparison to already available studies, the unique novelty is the use of non-rotational symmetric pin structures for the CFRT/metal hybrid joining. Thus, a variation in the fiber orientation in the CFRT component as well as a variation in the non-rotational symmetric pins’ orientation in relation to the sample orientation is conducted. The created samples are consequently mechanically tested via single lap shear experiments in a quasi-static state. Finally, the failure behavior of the single lap shear samples is investigated with the help of microscopic images and detailed photographs. In the single lap shear tests, it could be shown that non-rotational symmetric pin structures lead to an increase in maximum testing forces of up to 74% when compared to cylindrical pins. However, when normalized to the pin foot print related joint strength, only one polygonal pin variation showed increased joint strength in comparison to cylindrical pin structures. The investigation of the failure behavior showed two distinct failure modes. The first failure mode was failure of the CFRT component due to an exceedance of the maximum bearing strength of the pin-hole leading to significant damage in the CFRT component. The second failure mode was pin-deflection due to the applied testing load and a subsequent pin extraction from the CFRT component resulting in significantly less visible damage in the CFRT component. Generally, CFRT failure is more likely with a fiber orientation of 0° in relation to the load direction while pin extraction typically occurs with a fiber orientation of 90°. It is assumed that for future investigations, pin structures with an undercutting shape that creates an interlocking joint could counteract the tendency for pin-extraction and consequently lead to increased maximum joint strengths.}}, author = {{Popp, Julian and Römisch, David and Merklein, Marion and Drummer, Dietmar}}, 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 = {{10}}, publisher = {{MDPI AG}}, title = {{{Joining of CFRT/Steel Hybrid Parts via Direct Pressing of Cold Formed Non-Rotational Symmetric Pin Structures}}}, doi = {{10.3390/app12104962}}, volume = {{12}}, year = {{2022}}, } @article{32864, abstract = {{The further development of in-mold-assembly (IMA) technologies for structural hybrid components is of great importance for increasing the economic efficiency and thus the application potential. This paper presents an innovative IMA process concept for the manufacturing of bending loaded hybrid components consisting of two outer metal belts and an inner core structure made of glass mat reinforced thermoplastic (GMT). In this process, the core structure, which is provided with stiffening ribs and functional elements, is formed and joined to two metal belts in one single step. For experimental validation of the concept, the development of a prototypic molding tool and the manufacturing of hybrid beams including process parameters are described. Three-point bending tests and optical measurement technologies are used to characterize the failure behavior and mechanical properties of the produced hybrid beams. It was found that the innovative IMA process enables the manufacturing of hybrid components with high energy absorption and low weight in one step. The mass-specific energy absorption is increased by 693 % compared to pure GMT beams.}}, author = {{Stallmeister, Tim and Tröster, Thomas}}, issn = {{1662-9795}}, journal = {{Key Engineering Materials}}, keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}}, pages = {{1457--1467}}, publisher = {{Trans Tech Publications, Ltd.}}, title = {{{In-Mold-Assembly of Hybrid Bending Structures by Compression Molding}}}, doi = {{10.4028/p-5fxp53}}, volume = {{926}}, year = {{2022}}, }