@article{58348,
  abstract     = {{<jats:p> Clinching is a mechanical joining technology, in which a mainly form-fit joint is created by means of local cold forming. To characterize the load-bearing behavior of such joints, they are typically analyzed destructively, for example by tensile-shear tests in combination with metallographic sections. However, both the initiation and progress of failure can only be described to a limited extent by this method. Furthermore, these tests allow only limited conclusions about clinch points under in-service loading. More purposefully, clinch points can be analyzed nondestructively by combining in-situ computed tomography (CT) and transient dynamic analysis (TDA). The TDA continuously measures the dynamic behavior of the specimen and indicates failure events like crack initiation, which then can be evaluated thoroughly by stopping the test and performing a CT scan. To qualify the TDA for this task, it is necessary to link the observed damage behavior with specific dynamic characteristics. In this work, the complementation of in-situ CT and TDA is investigated by testing a clinched single-lap tensile-shear specimen made of aluminum. The testing procedure is stepwise: at certain displacement levels, the specimen is investigated by in-situ CT and TDA. While the in-situ CT provides the location, extent, and development of the failure phenomena, the TDA uses this information to evaluate the dynamic signal and detect relevant frequency ranges, which indicate damage events. The results demonstrate, that failure initiation and progression can be analyzed efficiently by combining both measuring systems. The TDA reliably detects relevant signal changes in the monitored frequency band. By means of in-situ computed tomography, the corresponding failure phenomena can be described in detail, enhancing the understanding of the load-bearing and deformation behavior of clinch points. The concatenation of characteristic signal changes and observed failure phenomena can henceforth be transferred to analyze complex structures during operation nondestructively by TDA. </jats:p>}},
  author       = {{Reschke, Gregor and Köhler, Daniel and Kupfer, Robert and Troschitz, Juliane and Gude, Maik and Brosius, Alexander}},
  issn         = {{0954-4089}},
  journal      = {{Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering}},
  keywords     = {{Clinching, Non-destructive testing, Transient Dynamic Analysis}},
  publisher    = {{SAGE Publications}},
  title        = {{{In-situ computed tomography and transient dynamic analysis – failure analysis of a single-lap tensile-shear test with clinch points}}},
  doi          = {{10.1177/09544089241251646}},
  year         = {{2024}},
}

@inbook{34212,
  abstract     = {{Force–displacement measurements and micrograph analyses are commonly used methods to validate numerical models of clinching processes. However, these methods often lead to resetting of elastic deformations and crack-
closing after unloading. In contrast, the in situ computed tomography (CT) can provide three-dimensional images of the clinch point under loading conditions. In this paper, the potential of the in situ investigation of a clinching process as validation method is analyzed. For the in situ testing, a tailored test set-up featuring a beryllium cylinder for load-bearing and clinching tools made from ultra-high-strength titanium and Si3N4 are used. In the experiments, the clinching of two aluminum sheets is interrupted at specific process steps in order to perform the CT scans. It is shown that in situ CT visualizes the inner geometry of the joint at high precision and that this method is suitable to validate numerical models.}},
  author       = {{Köhler, Daniel and Kupfer, Robert and Troschitz, Juliane and Gude, Maik}},
  booktitle    = {{The Minerals, Metals & Materials Series}},
  isbn         = {{9783031062117}},
  issn         = {{2367-1181}},
  keywords     = {{Clinching, Non-destructive testing, Computed tomography, In situ CT}},
  publisher    = {{Springer International Publishing}},
  title        = {{{Clinching in In Situ CT—A Novel Validation Method for Mechanical Joining Processes}}},
  doi          = {{10.1007/978-3-031-06212-4_75}},
  year         = {{2022}},
}