@article{30648, abstract = {{In clinching, the combinations of requirements, materials, component dimensions and tools influence the resulting joint geometry and the resulting bonding mechanisms. These in turn affect the property profile of the joint. For example, it is possible to use different tools to flexibly adapt clinching points to the respective required load regime. Clinching points dimensioned in this way can be geometrically similar, but have different mechanical stress states, which leads to different properties in terms of load-bearing behavior. Within the scope of this work, the clinching process with different tools in optimal and compromise design and its effect on the force and form-closure component, is investigated in a torsion test of the clinched connection. Clinched steel sheets with two thicknesses and joining directions are analyzed. Virtual experiments are carried out using finite element analyses (FEA) of the joining process and are followed by a springback simulation. Subsequently, the surface pressure between the two joining partners in the clinching points is calculated on the basis of the results from the FEA and the transmittable moment of the connection, as an indicator for the force-closure component, is determined. Finally, the experimental and simulated data are compared and discussed.}}, author = {{Steinfelder, C. and Kalich, J. and Brosius, A. and Füssel, U.}}, journal = {{IOP Conference Series: Materials Science and Engineering}}, pages = {{012003}}, title = {{{Numerical and experimental investigation of the transmission moment of clinching points}}}, doi = {{10.1088/1757-899x/1157/1/012003}}, volume = {{1157}}, year = {{2021}}, } @article{30649, abstract = {{Nowadays, the production of modern lightweight structures, like a body in white structure requires a wide variety of mechanical joining processes. To fulfill the various demands, mechanical joining processes and joining elements (JE) are used. Very often, they are adapted to the application, which leads in turn to a numerous of different variants, high costs, and loss of the process chain versatility. To overcome this drawback, an innovative approach is the usage of individually produced and task-adapted JE, the so-called friction spun joint connectors (FSJC). These connectors can be modified in shape as well as in material properties. This flexibility offers high potential for lightweight design but also increases the necessary analytical effort regarding the forming process as well as the manufactured joint's properties. Therefore, a new analysis strategy based on the Finite-Element-Method (FEM) is proposed, which numerically determines the local load bearing capacity within a given joint in order to identify the critical regions for load transfer. The process of joining element manufacturing and the analysis strategy will be described in detail and optimization results of the joints are shown. Numerical results are discussed and possible recommendations for joint manufacturing are derived.}}, author = {{Wischer, Christian and Steinfelder, Christian and Homberg, Werner and Brosius, Alexander}}, journal = {{IOP Conference Series: Materials Science and Engineering}}, pages = {{012007}}, title = {{{Joining with Friction Spun Joint Connectors – Manufacturing and Analysis}}}, doi = {{10.1088/1757-899x/1157/1/012007}}, volume = {{1157}}, year = {{2021}}, } @article{30680, author = {{Weiß, D. and Schramm, B. and Kullmer, G.}}, journal = {{Key Engineering Materials}}, pages = {{127--132}}, title = {{{Numerical and Experimental Fracture Mechanical Investigations of Clinchable Sheet Metals Made of HCT590X}}}, doi = {{10.4028/www.scientific.net/kem.883.127}}, volume = {{883}}, year = {{2021}}, } @article{30699, author = {{Weiß, D. and Schramm, B. and Kullmer, G.}}, journal = {{Production Engineering}}, title = {{{Holistic investigation chain for the experimental determination of fracture mechanical material parameters with special specimens}}}, doi = {{10.1007/s11740-021-01096-6}}, year = {{2021}}, } @article{30696, author = {{Zirngibl, C. and Schleich, B. and Wartzack, S.}}, journal = {{Proceedings of the Design Society}}, pages = {{521}}, title = {{{Approach for the automated and data-based design of mechanical joints}}}, doi = {{10.1017/pds.2021.52}}, volume = {{1}}, year = {{2021}}, } @article{30700, author = {{Zirngibl, C. and Dworschak, F. and Schleich, B. and Wartzack, S.}}, journal = {{Production Engineering}}, title = {{{Application of reinforcement learning for the optimization of clinch joint characteristics}}}, doi = {{10.1007/s11740-021-01098-4}}, year = {{2021}}, } @article{30663, abstract = {{The use of clinch joints, e.g. vehicle structures, is determined by the reliability of the joint and its strength properties - in particular the fatigue strength. Clinch connections offer the advantage over form-closure and force-closure processes that they can also be used for hybrid material combinations. In order to be able to evaluate the influence of the geometry parameters such as e.g. undercut, neck thickness or also base thickness on the fatigue behavior, three clinch connections (in optimum and compromise design) with different tool parameters were designed and examined using the example of a joining task with aluminum sheet material. For this purpose, fatigue curves (F-N curves) in the range of high to very high numbers of load cycles (N = 105 to 107) were determined. In this load cycle range, a so-called "neck fracture" is mainly to be expected as the type of failure, whereas for quasi-static tests, a “buckling” is more likely to occur. The tests were carried out on single-cut overlapping shear tensile specimens. Metallographic and scanning electron microscopic examinations of the joints and the fracture surfaces served to identify the crack initiation site and to clarify the respective type of failure. Significant differences in the damage behaviour of the three clinching variants could be shown. This observation enables one step into the direction of fully understanding the relationship along the causal chain "joint requirements - joining process - fatigue strength". Thus the adaptability of the clinching process can be improved. }}, author = {{Ewenz, L. and Kalich, J. and Zimmermann, M. and Füssel, U.}}, journal = {{Key Engineering Materials}}, pages = {{65--72}}, title = {{{Effect of Different Tool Geometries on the Mechanical Properties of Al-Al Clinch Joints}}}, doi = {{10.4028/www.scientific.net/kem.883.65}}, volume = {{883}}, year = {{2021}}, } @article{30664, abstract = {{Corrosion is a major cause for the failure of metallic components in various branches of the industry. Depending on the corrosion severity, the time until failure of the component varies. On the contrary, a study has shown that certain riveted metal joints, exposed to a short period of mechanical loading and corrosion, have greater fatigue limits. This study gives rise to the question how different corrosion exposure times affect joint metallic components. In the present research, a theoretical approach is developed in order to evaluate the influence of galvanic corrosion on joint integrity of clinched metal joints. At first, the framework for modeling galvanic corrosion is introduced. Furthermore, a simulative investigation of a clinching point is carried out based on the assumption that corrosion leads to a reduction of the contact area which leads to a local increase in contact pressure. For this purpose, the stiffness values of individual elements in a finite element model are reduced locally in the contact area of the undercut and the contact stress along a path is evaluated. Summarizing, a modeling approach is introduced to investigate corrosion effects on load-bearing behavior of clinched joints. }}, author = {{Harzheim, S. and Steinfelder, C. and Wallmersperger, T. and Brosius, A.}}, journal = {{Key Engineering Materials}}, pages = {{97--104}}, title = {{{A First Approach for the Treatment of Galvanic Corrosion and of Load-Bearing Capacity of Clinched Joints}}}, doi = {{10.4028/www.scientific.net/kem.883.97}}, volume = {{883}}, year = {{2021}}, } @article{30720, abstract = {{Predicting the durability of components under mechanical loading combined with environmental conditions leading to corrosion is one of the most challenging tasks in mechanical engineering. Precise predictions are neccesary for lightweight design in transportation due to environmental protection. During corrosion often hydrogen is produced by electrochemical reactions. Hydrogen embrittlement is one of the most feared damage mechanisms for metal constructions leading to early and unexpected failure. Until now predictions are mostly done through costly experiments. In the present research, a first simple simulation model based on the fundamentals of electrochemistry and continuum damage mechanics is developed to couple the damage induced by the mechanical stress with the hydrogen embrittlement. Results of the durability are presented for the case of uniaxial cyclic loading for varying testing frequency.}}, author = {{Hofmann, M. and Shi, Y. and Wallmersperger, T.}}, journal = {{PAMM}}, title = {{{A first Model of Fatigue Corrosion of a Metal through Hydrogen Embrittlement}}}, doi = {{10.1002/pamm.202000122}}, volume = {{20}}, year = {{2021}}, } @article{30695, abstract = {{Due to their cost-efficiency and environmental friendliness, the demand of mechanical joining processes is constantly rising. However, the dimensioning and design of joints and suitable processes are mainly based on expert knowledge and few experimental data. Therefore, the performance of numerical and experimental studies enables the generation of optimized joining geometries. However, the manual evaluation of the results of such studies is often highly time-consuming. As a novel solution, image segmentation and machine learning algorithm provide methods to automate the analysis process. Motivated by this, the paper presents an approach for the automated analysis of geometrical characteristics using clinching as an example. }}, author = {{Zirngibl, C. and Schleich, B.}}, journal = {{Key Engineering Materials}}, pages = {{105}}, title = {{{Approach for the automated analysis of geometrical clinch joint characteristics}}}, doi = {{10.4028/www.scientific.net/KEM.883.105}}, volume = {{883 KEM}}, year = {{2021}}, } @inproceedings{34472, author = {{Kullmer, Gunter and Weiß, Deborah and Schramm, Britta}}, location = {{Bremen}}, pages = {{107--116}}, title = {{{Entwicklung einer Methode zur differenzierten Messung des Wachstums der Rissenden von Innenrissen mit der Elektropotentialmethode}}}, doi = {{10.48447/BR-2021-013}}, volume = {{DVM-Bericht 253}}, year = {{2021}}, } @article{24541, abstract = {{The mechanical properties of joined structures are determined considerably by the chosen joining technology. With the aim of providing a method that enables a faster and more profound decision-making in the spatial distribution of joining points during product development, a new method for the load path analysis of joining points is presented. For an exemplary car body, the load type in the joining elements, i.e. pure tensile, shear and combined tensile-shear loads, is determined using finite element analysis (FEA). Based on the evaluated loads, the resulting load paths in selected joining points are analyzed using a 2D FE-model of a clinching point. State of the art methods for load path analysis are dependent on the selected coordinate system or the existing stress state. Thus, a general statement about the load transmission path is not possible at this time. Here, a novel method for the analysis of load paths is used, which is independent of the alignment of the analyzed geometry. The basic assumption of the new load path analysis method was confirmed by using a simple specimen with a square hole in different orientations. The results presented here show a possibility to display the load transmission path invariantly. In further steps, the method will be extended for 3D analysis and the investigation of more complex assemblies. The primary goal of this methodical approach is an even load distribution over the joining elements and the component. This will provide a basis for future design approaches aimed at reducing the number of joining elements in joined structures.}}, author = {{Steinfelder, Christian and Martin, Sven and Brosius, Alexander and Tröster, Thomas}}, issn = {{1662-9795}}, journal = {{Key Engineering Materials}}, pages = {{73--80}}, title = {{{Load Path Transmission in Joining Elements}}}, doi = {{10.4028/www.scientific.net/kem.883.73}}, year = {{2021}}, } @article{24548, author = {{Martin, Sven and Tröster, Thomas}}, journal = {{ESAFORM 2021}}, title = {{{Joint point loadings in car bodies – the influence of manufacturing tolerances and scatter in material properties}}}, doi = {{10.25518/esaform21.3801}}, year = {{2021}}, } @article{29293, author = {{Martin, Sven and Schütte, Jan and Bäumler, C. and Sextro, Walter and Tröster, Thomas}}, issn = {{2666-3597}}, journal = {{Forces in Mechanics}}, publisher = {{Elsevier BV}}, title = {{{Identification of joints for a load-adapted shape in a body in white using steady state vehicle simulations}}}, doi = {{10.1016/j.finmec.2021.100065}}, volume = {{6}}, year = {{2021}}, } @inproceedings{24006, author = {{Weiß, Deborah and Schramm, Britta and Neuser, Moritz and Grydin, Olexandr and Kullmer, Gunter}}, location = {{Bremen}}, pages = {{231--240}}, title = {{{Experimentelle bruchmechanische Untersuchung eines clinchgeeigneten Bleches aus HCT590X mithilfe einer neuen Probengeometrie}}}, doi = {{10.48447/BR-2021-025}}, volume = {{DVM-Bericht 253}}, year = {{2021}}, } @article{30706, author = {{Steinfelder, C. and Brosius, A.}}, journal = {{Lecture Notes in Production Engineering}}, pages = {{134--141}}, title = {{{A New Approach for the Evaluation of Component and Joint Loads Based on Load Path Analysis}}}, doi = {{10.1007/978-3-662-62138-7_14}}, year = {{2020}}, } @article{30711, author = {{Ewenz, L. and Schettler, S. and Zeuner, A. T. and Zimmermann, M.}}, journal = {{Tagung Werkstoffprüfung 2020. Werkstoffe und Bauteile auf dem Prüfstand. Prüftechnik - Kennwertermit}}, title = {{{Untersuchungen zum Einfluss von Geometrieparametern bei artgleichen Al-Clinchverbindungen auf das Ermüdungsverhalten im Bereich hoher bis sehr hoher Lastspielzahlen}}}, doi = {{10.48447/WP-2020-039}}, year = {{2020}}, } @article{30710, author = {{Zirngibl, C. and Schleich, B. and Wartzack, S.}}, journal = {{Proceedings of the 31st Symposium Design for X (DFX2020)}}, title = {{{Potentiale datengestützter Methoden zur Gestaltung und Optimierung mechanischer Fügeverbindungen}}}, doi = {{10.35199/dfx2020.8}}, year = {{2020}}, } @inproceedings{23980, author = {{Weiß, Deborah and Schramm, Britta and Kullmer, Gunter}}, location = {{online}}, pages = {{2335--2341}}, publisher = {{Elsevier}}, title = {{{Development of a special specimen geometry for the experimental determination of fracture mechanical parameters of clinchable metal sheets}}}, doi = {{10.1016/j.prostr.2020.11.081}}, volume = {{28}}, year = {{2020}}, } @article{16859, author = {{Martin, Sven and Camberg, Alan A. and Tröster, Thomas}}, issn = {{2351-9789}}, journal = {{Procedia Manufacturing}}, location = {{virtually}}, pages = {{419--424}}, publisher = {{Elsevier}}, title = {{{Probability Distribution of Joint Point Loadings in Car Body Structures under Global Bending and Torsion}}}, doi = {{10.1016/j.promfg.2020.04.324}}, year = {{2020}}, }