@inproceedings{59878,
abstract = {{Abstract. In the development of advanced lightweight automotive solutions, self-piercing riveting (SPR) offers the possibility of joining multi-material structures to fulfil a wide variety of requirements. With regard to the entire process chain, production-related pre-deformations of the parts to be joined can influence the geometric shape and load capacity of SPR joints. Various studies have investigated the influence of pre-stretched sheet materials, in the sense of pre-drawing processes, on the formation of SPR joints. The impact of pre-stretching sheet metals on the formation of their geometrical characteristics and the shear-tensile strength of SPR processes was observed [1]. Pre-rolled semi-finished products are also joined together in mixed material automotive structures, e.g. tailor rolled blanks. This work aims to investigate the influence of pre-rolled joining parts on the geometric formation and load-carrying capacity of SPR joints. For this purpose, sheets of metal are cold-formed using a rolling process to induce a defined strain-hardening state in the material and then joined in various combinations. As the degree of deformation increases, the rolling of samples can lead to minimal accumulation of damage in the sheet materials, which can influence the joint behaviour. The rolling process, as well as the subsequent joining process, are also investigated by FEM. The influence of pre-rolled semi-finished products on the strength of the SPR joints is investigated.}},
author = {{Schlichter, Malte Christian and Harabati, Özcan and Ludwig, Jean-Patrick and Böhnke, Max and Bielak, Christian Roman and Bobbert, Mathias and Meschut, Gerson}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Experimental and numerical investigation of the influence of rolling-induced sheet metal deformation on SPR joints}}},
doi = {{10.21741/9781644903599-148}},
volume = {{54}},
year = {{2025}},
}
@inproceedings{60977,
abstract = {{In the development of advanced lightweight automotive solutions, self-piercing riveting (SPR) offers the possibility of joining multi-material structures to fulfil a wide variety of requirements. With regard to the entire process chain, production-related pre-deformations of the parts to be joined can influence the geometric shape and load capacity of SPR joints. Various studies have investigated the influence of pre-stretched sheet materials, in the sense of pre-drawing processes, on the formation of SPR joints. The impact of pre-stretching sheet metals on the formation of their geometrical characteristics and the shear-tensile strength of SPR processes was observed [1]. Pre-rolled semi-finished products are also joined together in mixed material automotive structures, e.g. tailor rolled blanks. This work aims to investigate the influence of pre-rolled joining parts on the geometric formation and load-carrying capacity of SPR joints. For this purpose, sheets of metal are cold-formed using a rolling process to induce a defined strain-hardening state in the material and then joined in various combinations. As the degree of deformation increases, the rolling of samples can lead to minimal accumulation of damage in the sheet materials, which can influence the joint behaviour. The rolling process, as well as the subsequent joining process, are also investigated by FEM. The influence of pre-rolled semi-finished products on the strength of the SPR joints is investigated.}},
author = {{Schlichter, Malte Christian and Harabati, Özcan and Ludwig, Jean-Patrick and Böhnke, Max and Bielak, Christian Roman and Bobbert, Mathias and Meschut, Gerson}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Experimental and numerical investigation of the influence of rolling-induced sheet metal deformation on SPR joints}}},
doi = {{10.21741/9781644903599-148}},
volume = {{54}},
year = {{2025}},
}
@inproceedings{60978,
abstract = {{The present study is an experimental analysis of the influence of pre-forming on the failure behaviour of clinched specimens under quasi-static and cyclic loading conditions. In this context, the geometric formation of the clinched joints is taken into account, with regard to the loading behaviour. The study also includes a comparison of the failure behaviour of quasi-static and cyclic tested specimen. Testing is done on non-pre-deformed and pre-deformed specimens. For this purpose, experimental investigations are carried out on two material combinations consisting of HCT590X steel sheet and EN AW-6014 T4 aluminium sheet. The focus is on the fatigue analysis of the clinched joints. The aim is to identify the failure modes under cyclic loading and the crack formation with regard to forming operations prior to the joining process. The investigations show that the cyclic load-bearing behaviour of the HCT590X joints is reduced by introducing a plastic pre-deformation of the to be joined parts.}},
author = {{Schlichter, Malte Christian and Harabati, Özcan and Böhnke, Max and Bielak, Christian Roman and Bobbert, Mathias and Meschut, Gerson}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Investigation on manufacturing-induced pre-deformation on the fatigue behaviour of clinched joints}}},
doi = {{10.21741/9781644903551-16}},
volume = {{52}},
year = {{2025}},
}
@inproceedings{60002,
abstract = {{This study focuses on damage modeling across different mechanical joining processes within a process chain, specifically using clinching and self-pierce riveting (SPR). The aim is to apply a comprehensive model that captures the damage mechanisms and interactions in these technologies, optimizing them for enhanced performance and durability of aluminum joints. A GISSMO damage model was utilized, based on the stress states occurring during the joining process and a newly introduced damage testing method. This model was applied to both clinching and SPR processes. A detailed analysis of the stress states provided insights into their effect on the material. By incorporating these insights into the GISSMO model, improved accuracy in damage prediction was achieved. The model's application to clinching and SPR demonstrated its effectiveness in optimizing aluminum joint performance and durability, ensuring that the processes can be finely tuned to minimize damage and enhance joint quality.}},
author = {{Harabati, Özcan and Bielak, Christian Roman and Böhnke, Max and Schlichter, Malte Christian and Brockmeier, Marc and Bobbert, Mathias and Meschut, Gerson}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Cross-process damage modeling: A process-chain case study of clinching and self-pierced riveting for aluminum connections}}},
doi = {{10.21741/9781644903551-19}},
volume = {{52}},
year = {{2025}},
}
@inproceedings{60440,
abstract = {{The versatile self-pierce riveting (V-SPR) is a further development of semi-tubular self-pierce riveting. V-SPR enables adaptation to changing boundary conditions, such as a change in the material thickness combination, without varying the rivet die combination due to increased punch actuation and the use of multi-range capable rivets [1]. The inner punch first sets the rivet. The outer punch then forms the rivet head to the respective sheet thickness. For this, the rivet requires a hard shank and a ductile rivet head, which is achieved by an inductive local hardening process [2]. Until now, the joint formation of rivets with graded hardness profile has been challenging to estimate in the FEM simulation due to the inhomogeneous material conditions in the rivet. In this study, a method capable of reproducing the experimentally determined hardness levels of rivets in detail is shown. This FE model enables the realistic modelling of the mechanical properties of the rivet on the basis of the hardness profile in order to predict the correct deformation processes and stresses during the riveting process. First, the detailed experimental hardness mapping of the locally heat-treated rivets is transferred into the FE model. The FEM material model can predict the local strength of the rivet based on hardness by scaling the flow curves. To estimate the predictive capability of the FEM model, the joint formation of rivets with different graded hardness profiles is compared experimentally and simulative. Based on the validated model, the influence of different rivet hardness profiles on the joint formation is analysed numerically. By adapting the material model, a high level of correlation between the experiment's joint formation and the simulation can be achieved.}},
author = {{Holtkamp, Pia Katharina and Bielak, Christian Roman and Bobbert, Mathias and Meschut, Gerson}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Simulation of the joining process of graded hardened multi-range capable rivets}}},
doi = {{10.21741/9781644903599-153}},
volume = {{54}},
year = {{2025}},
}
@article{57742,
author = {{Böhnke, Max and Bielak, Christian Roman and Beck, Robert and Bobbert, Mathias and Meschut, Gerson}},
issn = {{2223-7690}},
journal = {{Friction}},
publisher = {{Tsinghua University Press}},
title = {{{Development of a friction model for the numerical simulation of clinching processes}}},
doi = {{10.26599/frict.2025.9441052}},
year = {{2024}},
}
@inproceedings{43090,
abstract = {{Abstract. The application of the mechanical joining process clinching allows the assembly of different sheet metal materials with a wide range of material thickness configurations, which is of interest for lightweight multi-material structures. In order to be able to predict the clinched joint properties as a function of the individual manufacturing steps, current studies focus on numerical modeling of the entire clinching process chain. It is essential to be able to take into account the influence of the joining process-induced damage on the load-bearing capacity of the joint during the loading phase. This study presents a numerical damage accumulation in the clinching process based on an implemented Hosford-Coulomb failure model using a 3D clinching process model applied on the aluminum alloy EN AW-6014 in temper T4. A correspondence of the experimentally determined failure location with the element of the highest numerically determined damage accumulation is shown. Moreover, the experimentally determined failure behavior is predicted to be in agreement in the numerical loading simulation with transferred pre-damage from the process simulation. }},
author = {{Bielak, Christian Roman and Böhnke, Max and Friedlein, Johannes and Bobbert, Mathias and Mergheim, Julia and Steinmann, Paul and Meschut, Gerson}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Numerical analysis of failure modeling in clinching process chain simulation}}},
doi = {{10.21741/9781644902417-33}},
year = {{2023}},
}
@inproceedings{43462,
abstract = {{Abstract. In the numerical simulation of mechanical joining technologies such as clinching, the material modeling of the joining parts is of major importance. This includes modeling the damage and failure behavior of the materials in accordance with varying occurring stress states. This paper presents a calibration method of three different fracture models. The calibration of the models is done by use of experimental data from a modified punch test, tensile test and bulge test in order to map the occurring stress states from clinching processes and to precisely model the resulting failure behavior. Experimental investigations were carried out for an aluminum alloy EN AW-6014 in temper T4 and compared with the simulative results generated in LS-DYNA. The comparison of force-displacement curves and failure initiation shows that the Hosford–Coulomb model predicts the failure behavior for the material used and the tests applied with the best accuracy. }},
author = {{Böhnke, Max and Bielak, Christian Roman and Friedlein, Johannes and Bobbert, Mathias and Mergheim, Julia and Steinmann, Paul and Meschut, Gerson}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{A calibration method for failure modeling in clinching process simulations}}},
doi = {{10.21741/9781644902417-34}},
year = {{2023}},
}
@inbook{52454,
author = {{Böhnke, Max and Bielak, Christian Roman and Bobbert, Mathias and Meschut, Gerson}},
booktitle = {{Lecture Notes in Mechanical Engineering}},
isbn = {{9783031413407}},
issn = {{2195-4356}},
publisher = {{Springer Nature Switzerland}},
title = {{{Experimental and Numerical Investigation of Clinched Joints Under Shear Tensile Loading at High Strain Rates}}},
doi = {{10.1007/978-3-031-41341-4_12}},
year = {{2023}},
}
@inproceedings{43463,
author = {{Friedlein, Johannes and Bielak, Christian Roman and Böhnke, Max and Bobbert, Mathias and Mergheim, Julia and Steinmann, Paul and Meschut, Gerson}},
booktitle = {{Materials Research Proceedings}},
publisher = {{Materials Research Forum LLC}},
title = {{{Influence of plastic orthotropy on clinching of sheet metal}}},
doi = {{10.21741/9781644902417-17 }},
year = {{2023}},
}
@book{55960,
author = {{Rossel, Moritz Sebastian and Meschut, Gerson and Bielak, Christian Roman and Otroshi, Mortaza}},
isbn = {{9783867766791}},
pages = {{124}},
publisher = {{ Europäische Forschungsgesellschaft für Blechverarbeitung e.V.}},
title = {{{Methodenentwicklung zur Verbesserung der Schädigungsmodellierung in der numerischen 3D-Belastungssimulation mechanischer Fügeverfahren unter Berücksichtigung der fügeinduzierten Vorbeanspruchung}}},
volume = {{610}},
year = {{2023}},
}
@inbook{52614,
author = {{Bielak, Christian Roman and Böhnke, Max and Bobbert, Mathias and Meschut, Gerson}},
booktitle = {{Lecture Notes in Mechanical Engineering}},
isbn = {{9783031413407}},
issn = {{2195-4356}},
publisher = {{Springer Nature Switzerland}},
title = {{{Numerical Investigation of the Coupled Friction Behavior in the Clinching Process Chain}}},
doi = {{10.1007/978-3-031-41341-4_15}},
year = {{2023}},
}
@article{34213,
abstract = {{In this paper, a study based on experimental and numerical simulations is performed to analyze fatigue cracks in clinched joints. An experimental investigation is conducted to determine the failure modes of clinched joints under cyclic loading at different load amplitudes with single-lap shear tests. In addition, numerical FEM simulations of clinching process and subsequent shear loading are performed to support the experimental investigations by analyzing the state of stresses at the location of failure. An attempt is made to explain the location of crack initiation in the experiments using evaluation variables such as contact shear stress and maximum principal stress.}},
author = {{Ewenz, L. and Bielak, Christian Roman and Otroshi, Mortaza and Bobbert, Mathias and Meschut, Gerson and Zimmermann, M.}},
issn = {{0944-6524}},
journal = {{Production Engineering}},
keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering}},
number = {{2-3}},
pages = {{305--313}},
publisher = {{Springer Science and Business Media LLC}},
title = {{{Numerical and experimental identification of fatigue crack initiation sites in clinched joints}}},
doi = {{10.1007/s11740-022-01124-z}},
volume = {{16}},
year = {{2022}},
}
@article{32413,
abstract = {{Background. Clinching is a conventional cold forming process in which two or more sheets can be joined without auxiliary parts. A pre-forming of the parts to be joined, which is introduced by previous manufacturing steps, has an influence on the joining result. When considering the suitability for joining with regard to the formability of the materials, the influence of the preforming steps must be taken into account. The influences of strain hardening and sheet thickness on the joining properties must be investigated. In this context, a Finite Element Method (FEM) based metamodel analysis of the clinching process was carried out in [1] to investigate the robustness of the clinching process with respect to the different material pre-strains. In [2], the method was extended to the load bearing simulation.Procedure. The metamodel from preliminary work based on various FE models, which predicts the load-bearing capacity of a clinched joint influenced by pre-straining, is compared here with experimental data and the accuracy of the metamodel prediction is discussed. For this purpose an experimental procedure was further develop which allows the preforming of metal sheets from which joining specimens can be separated with a certain degree of unidirectional deformation. In the study, the procedure for preparing the joint specimens and the results of the loading tests are presented. Different possible relevant pre-strain combinations are investigated and compared with the simulation results, to validate the FE models and choose suitable metamodel.}},
author = {{Bielak, Christian Roman and Böhnke, Max and Bobbert, Mathias and Meschut, Gerson}},
issn = {{1662-9795}},
journal = {{Key Engineering Materials}},
keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
pages = {{1516--1526}},
publisher = {{Trans Tech Publications, Ltd.}},
title = {{{Experimental and Numerical Investigation on Manufacturing-Induced Pre-Strain on the Load-Bearing Capacity of Clinched Joints}}},
doi = {{10.4028/p-5d009y}},
volume = {{926}},
year = {{2022}},
}
@article{31828,
author = {{Kupfer, Robert and Köhler, Daniel and Römisch, David and Wituschek, Simon and Ewenz, Lars and Kalich, Jan and Weiß, Deborah and Sadeghian, Behdad and Busch, Matthias and Krüger, Jan and Neuser, Moritz and Grydin, Olexandr and Böhnke, Max and Bielak, Christian Roman and Troschitz, Juliane}},
issn = {{2666-3309}},
journal = {{Journal of Advanced Joining Processes}},
keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}},
publisher = {{Elsevier BV}},
title = {{{Clinching of Aluminum Materials – Methods for the Continuous Characterization of Process, Microstructure and Properties}}},
doi = {{10.1016/j.jajp.2022.100108}},
volume = {{5}},
year = {{2022}},
}
@article{34215,
abstract = {{Clinching as a mechanical joining technique allows a fast and reliable joining of metal sheets in large-scale production. An efficient design and dimensioning of clinched joints requires a holistic understanding of the material, the joining process and the resulting properties of the joint. In this paper, the process chain for clinching metal sheets is described and experimental techniques are proposed to analyze the process-microstructure-property relationships from the sheet metal to the joined structure. At the example of clinching aluminum EN AW 6014, characterization methods are applied and discussed for the following characteristics: the mechanical properties of the sheet materials, the tribological behavior in the joining system, the joining process and the resulting material structure, the load-bearing behavior of the joint, the damage and degradation as well as the service life and crack growth behavior. The compilation of the characterization methods gives an overview on the advantages and weaknesses of the methods and the multiple interactions of material, process and properties during clinching. In addition, the results of the analyses on EN AW 6014 can be applied for parameterization and validation of simulations.}},
author = {{Kupfer, Robert and Köhler, Daniel and Römisch, David and Wituschek, Simon and Ewenz, Lars and Kalich, Jan and Weiß, Deborah and Sadeghian, Behdad and Busch, Matthias and Krüger, Jan Tobias and Neuser, Moritz and Grydin, Olexandr and Böhnke, Max and Bielak, Christian Roman and Troschitz, Juliane}},
issn = {{2666-3309}},
journal = {{Journal of Advanced Joining Processes}},
keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}},
publisher = {{Elsevier BV}},
title = {{{Clinching of Aluminum Materials – Methods for the Continuous Characterization of Process, Microstructure and Properties}}},
doi = {{10.1016/j.jajp.2022.100108}},
volume = {{5}},
year = {{2022}},
}
@inbook{33003,
author = {{Böhnke, Max and Bielak, Christian Roman and Bobbert, Mathias and Meschut, Gerson}},
booktitle = {{The Minerals, Metals & Materials Series}},
isbn = {{9783031062117}},
issn = {{2367-1181}},
location = {{Toronto, Kanada}},
publisher = {{Springer International Publishing}},
title = {{{Development of a Modified Punch Test for Investigating the Failure Behavior in Sheet Metal Materials}}},
doi = {{10.1007/978-3-031-06212-4_52}},
year = {{2022}},
}
@article{34572,
author = {{Böhnke, Max and Bielak, Christian Roman and Bobbert, Mathias and Meschut, Gerson}},
journal = {{Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications}},
publisher = {{SAGE Journals}},
title = {{{Experimental and numerical investigation of the influence of multiaxial loading conditions on the failure behavior of clinched joints}}},
doi = {{10.1177/14644207221145886}},
year = {{2022}},
}
@article{30100,
abstract = {{Since the application of mechanical joining methods, such as clinching or riveting, offers a robust solution for the generation of advanced multi-material connections, the use in the field of lightweight designs (e.g. automotive industry) is steadily increasing. Therefore, not only the design of an individual joint is required but also the dimensioning of the entire joining connection is crucial. However, in comparison to thermal joining techniques, such as spot welding, the evaluation of the joints’ resistance against defined requirements (e.g. types of load, minimal amount of load cycles) mainly relies on the consideration of expert knowledge, a few design principles and a small amount of experimental data. Since this generally implies the involvement of several domains, such as the material characterization or the part design, a tremendous amount of data and knowledge is separately generated for a certain dimensioning process. Nevertheless, the lack of formalization and standardization in representing the gained knowledge leads to a difficult and inconsistent reuse, sharing or searching of already existing information. Thus, this contribution presents a specific ontology for the provision of cross-domain knowledge about mechanical joining processes and highlights two potential use cases of this ontology in the design of clinched and pin joints.}},
author = {{Zirngibl, Christoph and Kügler, Patricia and Popp, Julian and Bielak, Christian Roman and Bobbert, Mathias and Drummer, Dietmar and Meschut, Gerson and Wartzack, Sandro and Schleich, Benjamin}},
issn = {{0944-6524}},
journal = {{Production Engineering}},
keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering}},
publisher = {{Springer Science and Business Media LLC}},
title = {{{Provision of cross-domain knowledge in mechanical joining using ontologies}}},
doi = {{10.1007/s11740-022-01117-y}},
year = {{2022}},
}
@inbook{34210,
abstract = {{The application of the mechanical joining process clinching enables the joining of sheet metals with a wide range of material-thickness configurations, which is of interest in lightweight construction of multi-material structures. Each material-thickness combination results in a joint with its own property profile that is affected differently by variations. Manufacturing process-related effects from preforming steps influence the geometric shape of a clinched joint as well as its load-bearing capacity. During the clinching process high degrees of plastic strain, increased temperatures and high strain rates occur. In this context, a 3D numerical model was developed which can represent the material-specific behaviour during the process chain steps sheet metal forming, joining, and loading phase in order to achieve a high predictive accuracy of the simulation. Besides to the investigation of the prediction accuracy, the extent of the influence of individual modelling aspects such as temperature and strain rate dependency is examined.}},
author = {{Bielak, Christian Roman and Böhnke, Max and Bobbert, Mathias and Meschut, Gerson}},
booktitle = {{The Minerals, Metals & Materials Series}},
isbn = {{9783031062117}},
issn = {{2367-1181}},
publisher = {{Springer International Publishing}},
title = {{{Development of a Numerical 3D Model for Analyzing Clinched Joints in Versatile Process Chains}}},
doi = {{10.1007/978-3-031-06212-4_15}},
year = {{2022}},
}