@article{51202,
  abstract     = {{<jats:p>When joining lightweight parts of various materials, clinching is a cost efficient solution. In a production line, the quality of a clinch point is primarily controlled by measurement of dimensions, which are accessible from outside. However, methods such as visual testing and measuring the bottom thickness as well as the outer diameter are not able to deliver any information about the most significant geometrical characteristic of the clinch point, neck thickness and undercut. Furthermore, ex-situ destructive methods such as microsectioning cannot detect elastic deformations and cracks that close after unloading. In order to exceed the current limits, a new non-destructive in-situ testing method for the clinching process is necessary. This work proposes a concept to characterize clinch points in-situ by combining two complementary non-destructive methods, namely, computed tomography (CT) and ultrasonic testing. Firstly, clinch points with different geometrical characteristics are analysed experimentally using ex-situ CT to get a highly spatially resolved 3D-image of the object. In this context, highly X-ray attenuating materials enhancing the visibility of the sheet-sheet interface are investigated. Secondly, the test specimens are modelled using finite element method (FEM) and a transient dynamic analysis (TDA) is conducted to study the effect of the geometrical differences on the deformation energy and to qualify the TDA as a fast in-situ non-destructive method for characterizing clinch points at high temporal resolution.</jats:p>}},
  author       = {{Köhler, Daniel and Sadeghian, Behdad and Kupfer, Robert and Troschitz, Juliane and Gude, Maik and Brosius, Alexander}},
  issn         = {{1662-9795}},
  journal      = {{Key Engineering Materials}},
  keywords     = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
  pages        = {{89--96}},
  publisher    = {{Trans Tech Publications, Ltd.}},
  title        = {{{A Method for Characterization of Geometric Deviations in Clinch Points with Computed Tomography and Transient Dynamic Analysis}}},
  doi          = {{10.4028/www.scientific.net/kem.883.89}},
  volume       = {{883}},
  year         = {{2021}},
}

@article{51199,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>Recent developments in automotive and aircraft industry towards a multi-material design pose challenges for modern joining technologies due to different mechanical properties and material compositions of various materials such as composites and metals. Therefore, mechanical joining technologies like clinching are in the focus of current research activities. For multi-material joints of metals and thermoplastic composites thermally assisted clinching processes with advanced tool concepts are well developed. The material-specific properties of fibre-reinforced thermoplastics have a significant influence on the joining process and the resulting material structure in the joining zone. For this reason, it is important to investigate these influences in detail and to understand the phenomena occurring during the joining process. Additionally, this provides the basis for a validation of a numerical simulation of such joining processes. In this paper, the material structure in a joint resulting from a thermally assisted clinching process is investigated. The joining partners are an aluminium sheet and a thermoplastic composite (organo sheet). Using computed tomography enables a three-dimensional investigation that allows a detailed analysis of the phenomena in different joining stages and in the material structure of the finished joint. Consequently, this study provides a more detailed understanding of the material behavior of thermoplastic composites during thermally assisted clinching.</jats:p>}},
  author       = {{Gröger, Benjamin and Köhler, Daniel and Vorderbrüggen, Julian and Troschitz, Juliane and Kupfer, Robert and Meschut, Gerson and Gude, Maik}},
  issn         = {{0944-6524}},
  journal      = {{Production Engineering}},
  keywords     = {{Industrial and Manufacturing Engineering, Mechanical Engineering}},
  number       = {{2-3}},
  pages        = {{203--212}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Computed tomography investigation of the material structure in clinch joints in aluminium fibre-reinforced thermoplastic sheets}}},
  doi          = {{10.1007/s11740-021-01091-x}},
  volume       = {{16}},
  year         = {{2021}},
}

@article{51200,
  abstract     = {{<jats:p>As lightweight design gains more and more attention, time and cost-efficient joining methods such as clinching are becoming more popular. A clinch point’s quality is usually determined by ex situ destructive analyses such as microsectioning. However, these methods do not yield the detection of phenomena occurring during loading such as elastic deformations and cracks that close after unloading. Alternatively, in situ computed tomography (in situ CT) can be used to investigate the loading process of clinch points. In this paper, a method for in situ CT analysis of a single-lap shear test with clinched metal sheets is presented at the example of a clinched joint with two 2 mm thick aluminum sheets. Furthermore, the potential of this method to validate numerical simulations is shown. Since the sheets’ surfaces are locally in contact with each other, the interface between both aluminum sheets and therefore the exact contour of the joining partners is difficult to identify in CT analyses. To compensate for this, the application of copper varnish between the sheets is investigated. The best in situ CT results are achieved with both sheets treated. It showed that with this treatment, in situ CT is suitable to properly observe the three-dimensional deformation behavior and to identify the failure modes.</jats:p>}},
  author       = {{Köhler, Daniel and Kupfer, Robert and Troschitz, Juliane and Gude, Maik}},
  issn         = {{1996-1944}},
  journal      = {{Materials}},
  keywords     = {{General Materials Science}},
  number       = {{8}},
  publisher    = {{MDPI AG}},
  title        = {{{In Situ Computed Tomography—Analysis of a Single-Lap Shear Test with Clinch Points}}},
  doi          = {{10.3390/ma14081859}},
  volume       = {{14}},
  year         = {{2021}},
}

@article{51201,
  abstract     = {{<jats:p>In lightweight design, clinching is a cost-efficient solution as the joint is created through localized cold-forming of the joining parts. A clinch point’s quality is usually assessed using ex-situ destructive testing methods. These, however, are unable to detect phenomena immediately during the joining process. For instance, elastic deformations reverse and cracks close after unloading. In-situ methods such as the force-displacement evaluation are used to control a clinching process, though deviations in the clinch point geometry cannot be derived with this method. To overcome these limitations, the clinching process can be investigated using in-situ computed tomography (in-situ CT). However, a clinching tool made of steel would cause strong artefacts and a high attenuation in the CT measurement, reducing the significance of this method. Additionally, when joining parts of the same material, the sheet-sheet interface is hardly detectable. This work aims at identifying, firstly, tool materials that allow artefact-reduced CT measurements during clinching, and, secondly, radiopaque materials that can be applied between the joining parts to enhance the detectability of the sheet-sheet interface. Therefore, both CT-suitable tool materials and radiopaque materials are selected and experimentally investigated. In the clinching process, two aluminium sheets with radiopaque material in between are clinched in a single-step (rotationally symmetric joint without cut section). It is shown that e.g. silicon nitride is suited as tool material and a tin layer is suitable to enhance the detectability of the sheet-sheet interface.</jats:p>}},
  author       = {{Köhler, Daniel and Kupfer, Robert and Troschitz, Juliane and Gude, Maik}},
  journal      = {{ESAFORM 2021}},
  publisher    = {{University of Liege}},
  title        = {{{Clinching in In-situ CT – Experimental Study on Suitable Tool Materials}}},
  doi          = {{10.25518/esaform21.2781}},
  year         = {{2021}},
}

@article{51198,
  author       = {{Köhler, D. and Sadeghian, B. and Troschitz, J. and Kupfer, R. and Gude, M. and Brosius, A.}},
  issn         = {{2666-3309}},
  journal      = {{Journal of Advanced Joining Processes}},
  keywords     = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}},
  publisher    = {{Elsevier BV}},
  title        = {{{Characterisation of lateral offsets in clinch points with computed tomography and transient dynamic analysis}}},
  doi          = {{10.1016/j.jajp.2021.100089}},
  volume       = {{5}},
  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{20678,
  author       = {{Bielak, Christian Roman and Böhnke, Max and Beck, Robert and Bobbert, Mathias and Meschut, Gerson}},
  journal      = {{Journal of Advanced Joining Processes. }},
  keywords     = {{Clinching, process simulation, FEM, pre-straining, sensitivity analysis}},
  publisher    = {{Elsevier}},
  title        = {{{Numerical analysis of the robustness of clinching process considering the pre-forming of the parts }}},
  doi          = {{https://doi.org/10.1016/j.jajp.2020.100038}},
  year         = {{2020}},
}

@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{30704,
  author       = {{Böhm, H. and Zhang, H. and Gröger, B. and Hornig, A. and Gude, M.}},
  journal      = {{Journal of Composites Science}},
  pages        = {{188}},
  title        = {{{Characterization and Numerical Modelling of Through-Thickness Metallic-Pin-Reinforced Fibre/Thermoplastic Composites under Bending Loading}}},
  doi          = {{10.3390/jcs4040188}},
  volume       = {{4}},
  year         = {{2020}},
}

@article{30707,
  author       = {{Sadeghian, B. and Guilleaume, C. and Lafarge, R. and Brosius, A.}},
  journal      = {{Lecture Notes in Production Engineering}},
  pages        = {{116--124}},
  title        = {{{Investigation of Clinched Joints – A Finite Element Simulation of a Non-destructive Approach}}},
  doi          = {{10.1007/978-3-662-62138-7_12}},
  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{30712,
  author       = {{Köhler, D. and Gröger, B. and Kupfer, R. and Hornig, A. and Gude, M.}},
  journal      = {{Procedia Manufacturing}},
  pages        = {{940--947}},
  title        = {{{Experimental and Numerical Studies on the Deformation of a Flexible Wire in an Injection Moulding Process}}},
  doi          = {{10.1016/j.promfg.2020.04.288}},
  volume       = {{47}},
  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}},
}

@article{30709,
  author       = {{Köhler, D. and Kupfer, R. and Gude, M.}},
  journal      = {{Journal of Advanced Joining Processes}},
  pages        = {{100034}},
  title        = {{{Clinching in in-situ CT—A numerical study on suitable tool materials}}},
  doi          = {{10.1016/j.jajp.2020.100034}},
  volume       = {{2}},
  year         = {{2020}},
}

@article{30703,
  author       = {{Kraus, M. and Merklein, M.}},
  journal      = {{Journal of Materials Processing Technology}},
  pages        = {{116697}},
  title        = {{{Potential of Joining Dissimilar Materials by Cold Formed Pin-Structures}}},
  doi          = {{10.1016/j.jmatprotec.2020.116697}},
  volume       = {{283}},
  year         = {{2020}},
}

@inproceedings{20344,
  author       = {{Bielak, Christian Roman and Böhnke, Max and Bobbert, Mathias and Meschut, Gerson}},
  location     = {{Darmstadt}},
  title        = {{{Development of a numerical method for analyzing the robustness of clinching in versatile process chains}}},
  year         = {{2020}},
}

@article{30721,
  author       = {{Wituschek, S. and Kuball, C. M. and Merklein, M. and Lechner, M.}},
  journal      = {{Defect and Diffusion Forum}},
  pages        = {{132--137}},
  title        = {{{Test Method for Friction Characterization of Rivets}}},
  doi          = {{10.4028/www.scientific.net/ddf.404.132}},
  volume       = {{404}},
  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}},
}

@inproceedings{23982,
  author       = {{Weiß, Deborah and Schramm, Britta and Kullmer, Gunter}},
  location     = {{Darmstadt}},
  title        = {{{Experimental and numerical preliminary investigations of the base material and preformed components regarding fatigue crack growth in joined structures}}},
  year         = {{2020}},
}