@article{22272, abstract = {{The number of multi-material joints is increasing as a result of lightweight design. Self-piercing riveting (SPR) is an important mechanical joining technique for multi-material structures. Rivets for SPR are coated to prevent corrosion, but this coating also influences the friction that prevails during the joining process. The aim of the present investigation is to evaluate this influence. The investigation focuses on the common rivet coatings Almac® and zinc-nickel with topcoat as well as on uncoated rivet surfaces. First of all, the coating thickness and the uniformity of the coating distribution are analysed. Friction tests facilitate the classification of the surface properties. The influence of the friction on the characteristic joint parameters and the force-stroke curves is analysed by means of experimental joining tests. More in-depth knowledge of the effects that occur is achieved through the use of numerical simulation. Overall, it is shown that the surface condition of the rivet has an impact on the friction during the joining process and on the resulting joint. However, the detected deviations between different surface conditions do not restrict the operational capability of SPR and the properties of uncoated rivet surfaces, in particular, are similar to those of Almac®-coated rivets. It can thus be assumed that SPR with respect to the joining process is also possible without rivet coating in principle.}}, author = {{Uhe, Benedikt and Kuball, Clara-Maria and Merklein, Marion and Meschut, Gerson}}, journal = {{Key Engineering Materials}}, keywords = {{Coating, Friction, Joining}}, pages = {{11--18}}, title = {{{Influence of the Rivet Coating on the Friction during Self-Piercing Riveting}}}, doi = {{10.4028/www.scientific.net/KEM.883.11}}, volume = {{883}}, year = {{2021}}, } @phdthesis{19743, author = {{Ditter, Jan}}, isbn = {{978-3-8440-7530-4}}, title = {{{Methodenentwicklung zum Entfügen von Stahl-Klebverbindungen bei tiefen Temperaturen}}}, year = {{2020}}, } @article{19753, author = {{Ditter, Jan and Aubel, Tobias and Meschut, Gerson}}, journal = {{adhesion ADHESIVES + SEALANTS}}, number = {{1}}, title = {{{Simple Determination of Fast Curing Parameters for Bonded Structures}}}, year = {{2020}}, } @techreport{20145, abstract = {{Der Karosseriebau ist zunehmend durch die Verwendung unterschiedlicher Werkstoffe in Mischbauweise gekennzeichnet, was zu einem Einsatz von mechanischen Fügeverfahren geführt hat. Hieraus resultieren die Zielsetzungen, die mechanischen Fügeverfahren in ihrer Effizienz und ihren Einsatzbereichen zu erweitern, sowie die Anzahl der Experimente zu reduzieren und Entwicklungszyklen zu verkürzen. Dies erfolgt mit Unterstützung der numerischen Simulation. Neben der Beschreibung des plastischen Verhaltens gilt es auch, das Schädigungsverhalten abzubilden. Der Fügeprozess bzw. die Fügerichtung erfolgt senkrecht zur Blechoberfläche und führt somit zu einem dreidimensionalen Zustand der Fügelemente. Hieraus leitet sich die Herausforderung ab, das Werkstoffversagen in Abhängigkeit der Beanspruchungssituation zu beschreiben. Ein einfacher Ansatz zur Abbildung des Durchdringens ist ein geometrisches Trennkriterium. Ein solches Kriterium basiert i.d.R. auf einem experimentell beobachteten Verhalten und ist somit nicht prognosefähig für Variationen bzgl. Werkzeugkonfigurationen, Blechdicken- und Werkstoffgüten-Kombinationen. In diesem Projekt wird das Schädigungsmodell GISSMO (Generalized Incremental Stress State dependent damage Model) verwendet, um die Entwicklung der duktilen Schädigung zu beschreiben und den Bruchbeginn während des Stanzniet- und Schneidclinchens vorherzusagen. Der Spannungszustand während der Prozesssimulation wird untersucht und die verschiedenen Schädigungsproben werden experimentell erprobt, um die Versagenskurven zu charakterisieren. Die Versagenskurven werden im Schädigungsmodell GISSMO definiert. Um die Genauigkeit des Modells zu gewährleisten, wird die Verifizierung des Modells durch die Simulation von Schädigungsproben mit dem Schädigungsmodell durchgeführt. Zur Validierung des Modells wird die Simulation des Fügeprozesses mit dem Schädigungsmodell durchgeführt und die Ergebnisse von Simulation und Experiment verglichen. Darüber hinaus werden Sensitivitätsanalysen durchgeführt, um die Einflüsse der Fertigungsprozesse, der Lackierung und des Diskretisierungsgrades auf das Schädigungsverhalten des Materials zu identifizieren. Das IGF-Vorhaben „Methodenentwicklung zur Schädigungsmodellierung für die numerische Prozesssimulation mechanischer Fügeverfahren" der Forschungsvereinigung EFB e.V. wurde unter der Fördernummer AiF 19452N über die Arbeitsgemeinschaft industrieller Forschungsvereinigungen (AiF) im Rahmen des Programms zur Förderung der Industriellen Gemeinschaftsforschung (IGF) vom Bundesministerium für Wirtschaft und Energie aufgrund eines Beschlusses des Deutschen Bundestages gefördert. Der Abschlussbericht ist als EFB-Forschungsbericht Nr. 527 erschienen und bei der EFB-Geschäftsstelle und im Buchhandel erhältlich.}}, author = {{Otroshi, Mortaza and Meschut, Gerson}}, isbn = {{978-3-86776-582-4}}, pages = {{182}}, publisher = {{Europäische Forschungsgesellschaft für Blechverarbeitung e.V.}}, title = {{{Methodenentwicklung zur Schädigungsmodellierung für die numerische Prozesssimulation mechanischer Fügeverfahren}}}, year = {{2020}}, } @inproceedings{20146, abstract = {{Joining technology is regarded as a key technology for reducing energy consumption and CO2 imitation as well as the use of innovative materials and development of new, resource-saving products. Punch riveting is a widely used and established joining process in many sectors. The white and brown goods, electrical engineering, construction and, in particular, the automotive industry are some of the sectors mentioned here. Since the design and assessment of punch rivet components with regard to structural durability can only be carried out experimentally using prototypes due to a lack of experience and calculation concepts, the improvement of this uneconomical and time-consuming procedure is the goal of this contribution. Therefore, a numerical simulation and design method for cyclically loads punched riveted joints shall be introduced. This concept shall be based on the notch strain concept. The following steps are necessary to achieve the goal shown above: Tensile tests on all materials involved in the joint for determination of tensile strength and quasi-static stress-strain curves Estimation of the cyclic material properties from the tensile strength in order to obtain the strain-life curve and the cyclic stress-strain curve Estimation of mean stress sensitivity from the tensile strength to conduct an amplitude transformation for variable amplitude loadings. Execution of a 2D forming simulation of the joining process to determine the geometry and the stresses and degrees of deformation present in the connection Transferring the results of the forming simulation into a static-mechanical load simulation for determining the relation between the external load and the elastic-plastic strain at the critical point Estimation of the service life by means of the damage parameter Wöhler curves calculated from the strain-life curve In order to verify the simulation and calculation method, service life investigations have been carried out on punched riveted components under constant and variable amplitude load. The test results, as well as the workflow through the fatigue assessment and its accuracy in estimation the fatigue life will be shown in this contribution.}}, author = {{Masendorf, Lukas and Wächter, Michael and Horstmann, Stephan and Otroshi, Mortaza and Esderts, Alfons and Meschut, Gerson}}, isbn = {{978-3-9820591-0-5}}, keywords = {{punch rivet, notch strain conept, structural durability}}, location = {{Darmstadt, Germany}}, publisher = {{Deutscher Verband für Materialforschung und -prüfung e.V.}}, title = {{{Linear damage accumulation of self-pierce riveted joints}}}, year = {{2020}}, } @article{20170, author = {{Otroshi, Mortaza and Meschut, Gerson}}, issn = {{0300-3167}}, journal = {{Umformtechnik Blech Rohre Profile}}, number = {{7/20}}, pages = {{48--50}}, title = {{{Spannungszustandsabhängige Schädigungsmodellierung zum Halbhohlstanznieten}}}, year = {{2020}}, } @article{20235, author = {{Heyser, Per and Sartisson, Vadim and Meschut, Gerson and Droß, Marcel and Dröder, Klaus}}, issn = {{0025-5300}}, journal = {{Materials Testing}}, pages = {{55--60}}, title = {{{Increased load bearing capacity of mechanically joined FRP/metal joints using a pin structured auxiliary joining element}}}, doi = {{10.3139/120.111453}}, year = {{2020}}, } @article{20269, author = {{Böhne, Christoph and Meschut, Gerson and Biegler, Max and Rethmeier, Michael}}, journal = {{Science and Technology of Welding and Joining}}, number = {{7}}, pages = {{617--624}}, publisher = {{Taylor & Francis}}, title = {{{Avoidance of liquid metal embrittlement during resistance spot welding by heat input dependent hold time adaption}}}, doi = {{10.1080/13621718.2019.1693731}}, volume = {{25}}, year = {{2020}}, } @inproceedings{20273, author = {{Biegler, Max and Rethmeier, Michael and Böhne, Christoph and Meschut, Gerson}}, booktitle = {{Joining in Car Body Engineering}}, title = {{{Resistance spot welding simulation can determine the critical stress- and strain-conditions leading to liquid metal embrittlement formation}}}, year = {{2020}}, } @techreport{21152, abstract = {{In modern lightweight designs, it is important to find a compromise between the strength and the weight of the construction detail. Hence, hybrid structures made of aluminum and steel materials are increasingly being used in automotive applications. Due to limitations in the quality of resistance spot welding, self-piercing riveting can be used as an alternative process to join sheets from different material groups. The aim of this project is to develop a computational method to assess the self-piercing riveted components subjected to the cyclic loads. To achieve this goal, two approaches are followed: Evaluation unsing internal forces: A substitute model is developed to describe the stiffness of self-piercing riveted joints subjected to different loading conditions. The parameters of the substitute model are identified and the internal force components acting on the joint are evaluated. The model provides the basis for the subsequent fatigue life estimation of self-piercing riveted components. For joints subjected to low bending moments, the fatigue life of components can be estimated accurately. Due to lack of specimen geometries producing pure bending and the combination of tension-bending forces, it is not possible to estimate the fatigue life of complex components subjected to high bending moments. Based on the results of [Mesc 16], the methodology is further developed to determine the stresses acting on the joint and to characterize the joining point with the use of simulations. The local concept proposed in the FKM guideline nonlinear provides the basis for the analytical assessment of self-piercing riveted components. In this regard, the cyclic behavior of the material and the local stresses are required as input data. The cyclic behavior of the aluminum EN AW-6181A-T6 and steel HX340LAD sheets were already determined in the previous project. Subsequently, in this project the properties of the rivet made of 38B2 steel are identified. The finite element analysis using elastic-plastic material behavior is used to determine the stresses in the joint subjected to the cyclic loads. To verify the model, the results of simulations and experiments are compared concerning the crack initiation zone as well as the determined number of cycles. To determine the stresses that can be used for the analytical assessment, the damage relevant load components need to be identified. In this regard, it is recommended to use the normal stress perpendicular to the crack propagation direction, the stress of crack opening mode I. Using the damage parameter PRAM and considering the support factors according to the FKM guideline nonlinear, a reliable estimation of the crack initiation zone within the joint is possible. Regarding the joint made of aluminum sheet EN AW-6181A, the methodology is able to provide promising results. However, regarding the joints made of aluminum EN AW-6181A and steel HX340LAD sheets, there is still potential to improve the results. The reasons for this are described in chapter 7.2.5 and 7.2.6. An analytical fatigue assessment is relatively easy to achieve with procedure 1. However, contrary to the objective formulated above, expensive fatigue tests are necessary to determine the failure conditions (strength values). This disadvantage can be circumvented by determining the strength information of individual joining points under different load types using procedure 2. The latter, in return, is not suitable for the assessment of complex components with several joining points. Due to the increasing calculation times of the simulation, the application in this case is not economically reasonable. By the described combination of method 1 and 2, the disadvantages of the two individual concepts can be compensated. An analytical fatigue assessment of self-piercing riveted components can be carried out based on the cyclic material behavior. The objective of the project was achieved.}}, author = {{Otroshi, Mortaza and Meschut, Gerson and Masendorf, Lukas and Esderts, Alfons}}, isbn = {{978-3-86776-602-9}}, pages = {{282}}, publisher = {{Europäische Forschungsgesellschaft für Blechverarbeitung e.V. (EFB)}}, title = {{{Simulationsbasierte Betriebsfestigkeitsanalyse stanzgenieteter Bauteile}}}, year = {{2020}}, } @inproceedings{19178, author = {{Kowatz, Jannik and Teutenberg, Dominik and Meschut, Gerson}}, booktitle = {{20. Kolloquium Gemeinsame Forschung in der Klebtechnik}}, location = {{Würzburg}}, title = {{{Auslegungsmethode für zyklisch beanspruchte Stahl/CFK-Klebverbindungen unter besonderer Berücksichtigung des Rissfortschritts}}}, year = {{2020}}, } @inproceedings{20301, author = {{Günter, Heinrich and Meschut, Gerson}}, booktitle = {{73rd IIW Annual Assembly and International Conference}}, title = {{{Joining of high-strength steel grades in lightweight structures using single-stage resistance element welding on conventional resistance spot welding machines}}}, year = {{2020}}, } @inproceedings{20316, author = {{Krüger, Christopher and Schmolke, Tobias and Merdivan, David and Spohr, Sebastian and Urban, Peter and Meschut, Gerson}}, location = {{Aachen}}, title = {{{Concept Development for a Functional Integrated Lightweight Battery Housing with Special Consideration of the Joining Technology}}}, year = {{2020}}, } @book{20318, author = {{Göddecke, Johannes and Meschut, Gerson and Gude, Maik and Lieberwirth, Holger and Tekkaya, Erman and Zaeh, Michael and Stegelmann, Michael and Müller, Michael and Böhme, Kurt and Krampitz, Thomas and Zöllner, Mareen and Hahn, Marlon and Schmitz, Fabian and Hofer, Andreas and Grohmann, Sandra}}, isbn = {{978-3867806435}}, pages = {{82}}, publisher = {{Plattform FOREL}}, title = {{{FOREL-Wegweiser: Handlungsempfehlungen für den ressourceneffizienten Leichtbau }}}, year = {{2020}}, } @inproceedings{20321, author = {{Göddecke, Johannes and Meschut, Gerson and Teutenberg, Dominik and Ummenhofer, Thomas and Albiez, Matthias and Damm, Jannis and Matzenmiller, Anton and Kötz, Fabian}}, booktitle = {{20. Kolloquium Gemeinsame Forschung in der Klebtechnik}}, title = {{{Experimentelle und numerische Untersuchung der Dämpfungseigenschaften geklebter Strukturen unter dynamischer Beanspruchung}}}, year = {{2020}}, } @inproceedings{20331, author = {{Ditz, Michael and Meschut, Gerson and Schwarze, Thomas and Smart, Dominic}}, location = {{Würzburg}}, title = {{{Entwicklung und Qualifizierung einer rechnergestützten Auswertemethode zur Differenzierung der Versagensanteile klebtechnisch gefügter Proben}}}, year = {{2020}}, } @inproceedings{20378, author = {{Çavdar, Serkan and Teutenberg, Dominik and Meschut, Gerson and Wulf, A. and Hesebeck, O. and Brede, M. and Mayer, B. and Tittmann, K. and Koch, I. and Jäger, H. and Wacker, J.-D. and Rybar, G. and Melz, T.}}, booktitle = {{20. Kolloquium Gemeinsame Forschung in der Klebtechnik}}, location = {{Würzburg}}, title = {{{Lebensdauerberechnung hybrider Verbindungen}}}, year = {{2020}}, } @inproceedings{20380, author = {{Çavdar, Serkan and Meschut, Gerson and Wulf, A. and Hesebeck, O. and Brede, M. and Mayer, B. and Tittmann, K. and Koch, I. and Jäger, H. and Wacker, J.-D. and Rybar, G. and Melz, T.}}, booktitle = {{DVS Congress 2020}}, location = {{Webkonferenz}}, title = {{{Berechnen der Lebensdauer hybrider Verbindungen}}}, year = {{2020}}, } @inproceedings{20381, author = {{Çavdar, Serkan and Meschut, Gerson and Wulf, A. and Hesebeck, O. and Brede, M. and Mayer, B.}}, booktitle = {{Joining in Car Body Engineering 2020}}, location = {{Webmeeting}}, title = {{{Fatigue life prediction of adhesively bonded FRP-aluminium-joints with hyperelastic behavior under cyclic multiaxial stress state}}}, year = {{2020}}, } @inproceedings{20409, author = {{Heyser, Per and Scharr, Christian and Nehls, Thomas and Wiesenmayer, Sebastian and Flügge, Wilko and Meschut, Gerson}}, booktitle = {{4. Workshop Digitalisierung}}, location = {{Erlangen}}, title = {{{Prozesskettenbegleitende Vorgehensweise beim Mechanischen Fügen}}}, year = {{2020}}, }