@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{33002,
abstract = {{Many mechanical material properties show a dependence on the strain rate, e.g. yield stress or elongation at fracture. The quantitative description of the material behavior under dynamic loading is of major importance for the evaluation of crash safety. This is carried out using numerical methods and requires characteristic values for the materials used. For the standardized determination of dynamic characteristic values in sheet metal materials, tensile tests performed according to the guideline from [1]. A particular challenge in dynamic tensile tests is the force measurement during the test. For this purpose, strain gauges are attached on each specimen, wired to the measuring equipment and calibrated. This is a common way to determine a force signal that is as low in vibration and as free of bending moments as possible. The preparation effort for the used strain gauges are enormous. For these reasons, an optical method to determine the force by strain measurement using DIC is presented. The experiments are carried out on a high speed tensile testing system. In combioantion with a 3D DIC high speed system for optical strain measurement. The elastic deformation of the specimen in the dynamometric section is measured using strain gauges and the optical method. The measured signals are then compared to validate the presented method. The investigations are conducted using the dual phase steel material HCT590X and the aluminum material EN AW-6014 T4. Strain rates of up to 240 s-1 are investigated.}},
author = {{Böhnke, Max and Unruh, Eduard and Sell, Stanislaw and Bobbert, Mathias and Hein, David and Meschut, Gerson}},
issn = {{1662-9795}},
journal = {{Key Engineering Materials}},
keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
location = {{Braga, Portugal}},
pages = {{1564--1572}},
publisher = {{Trans Tech Publications, Ltd.}},
title = {{{Functionality Study of an Optical Measurement Concept for Local Force Signal Determination in High Strain Rate Tensile Tests}}},
doi = {{10.4028/p-wpuzyw}},
volume = {{926}},
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{34216,
abstract = {{Mechanical joining technologies are increasingly used in multi-material lightweight constructions and offer opportunities to create versatile joining processes due to their low heat input, robustness to metallurgical incompatibilities and various process variants. They can be categorised into technologies which require an auxiliary joining element, or do not require an auxiliary joining element. A typical example for a mechanical joining process with auxiliary joining element is self-piercing riveting. A wide range of processes exist which are not requiring an auxiliary joining element. This allows both point-shaped (e.g., by clinching) and line-shaped (e.g., friction stir welding) joints to be produced. In order to achieve versatile processes, challenges exist in particular in the creation of intervention possibilities in the process and the understanding and handling of materials that are difficult to join, such as fiber reinforced plastics (FRP) or high-strength metals. In addition, predictive capability is required, which in particular requires accurate process simulation. Finally, the processes must be measured non-destructively in order to generate control variables in the process or to investigate the cause-effect relationship. This paper covers the state of the art in scientific research concerning mechanical joining and discusses future challenges on the way to versatile mechanical joining processes.}},
author = {{Meschut, Gerson and Merklein, M. and Brosius, A. and Drummer, D. and Fratini, L. and Füssel, U. and Gude, M. and Homberg, Werner and Martins, P.A.F. and Bobbert, Mathias and Lechner, M. and Kupfer, R. and Gröger, B. and Han, Daxin and Kalich, J. and Kappe, Fabian and Kleffel, T. and Köhler, D. and Kuball, C.-M. and Popp, J. and Römisch, D. and Troschitz, J. and Wischer, Christian and Wituschek, S. and Wolf, M.}},
issn = {{2666-3309}},
journal = {{Journal of Advanced Joining Processes}},
keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}},
publisher = {{Elsevier BV}},
title = {{{Review on mechanical joining by plastic deformation}}},
doi = {{10.1016/j.jajp.2022.100113}},
volume = {{5}},
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}},
}
@article{30962,
abstract = {{ Clinching as a mechanical joining process has become established in many areas of car body. In order to predict relevant properties of clinched joints and to ensure the reliability of the process, it is numerically simulated during the product development process. The prediction accuracy of the simulated process depends on the implemented friction model. Therefore, a new method for determining friction coefficients in sheet metal materials was developed and tested. The aim of this study is the numerical investigation of this experimental method by means of FE simulation. The experimental setup is modelled in a 3D numerical simulation taking into account the process parameters varying in the experiment, such as geometric properties, contact pressure and contact velocity. Furthermore, the contact description of the model is calibrated via the experimentally determined friction coefficients according to clinch-relevant parameter space. It is shown that the assumptions made in the determination of the experimental data in preliminary work are valid. In addition, it is investigated to what extent the standard Coulomb friction model in the FEM can reproduce the results of the experimental method. }},
author = {{Bielak, Christian Roman and Böhnke, Max and Bobbert, Mathias and Meschut, Gerson}},
issn = {{1464-4207}},
journal = {{Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications}},
keywords = {{Mechanical Engineering, General Materials Science}},
publisher = {{SAGE Publications}},
title = {{{Numerical investigation of a friction test to determine the friction coefficients for the clinching process}}},
doi = {{10.1177/14644207221093468}},
year = {{2022}},
}
@article{29951,
abstract = {{The components of a body in white consist of many individual thin-walled sheet metal parts, which usually are manufactured in deep-drawing processes. In general, the conditions in a deep-drawing process change due to changing tribology conditions, varying degrees of spring back, or scattering material properties in the sheet blanks, which affects the resulting pre-strain. Mechanical joining processes, especially clinching, are influenced by these process-related pre-strains. The final geometric shape of a clinched joint is affected to a significant level by the prior material deformation when joining with constant process parameters. That leads to a change in the stiffness and force transmission in the clinched joint due to the different geometric dimensions, such as interlock, neck thickness and bottom thickness, which directly affect the load bearing capacity. Here, the influence of the pre-straining in the deep drawing process on the force distribution in clinch points in an automotive assembly is investigated by finite-element models numerically. In further studies, the results are implemented in an optimization tool for designing clinched components. The methodology starts with a pre-straining of metal sheets. This step is followed by 2D rotationally symmetric forming simulations of the joining process. The resulting mesh of each forming simulation is rotated and 3D models are obtained. The clinched joint solid model with pre-strains is used further to determine the joint stiffnesses. With the simulation of the same test set-up with an equivalent point-connector model, the equivalent stiffness for each pre-strain combination is determined. Simulations are performed on a clinched component to assess the influence of pre-strain and sheet thinning on the clinched joint loadings by using the equivalent stiffnesses. The investigations clearly show that for the selected component, the loadings at the clinch points are dependent on the sheet thinning and the stiffnesses due to pre-strain. The magnitude of the influence varies depending on the quantity considered. For example, the shear force is more sensitive to the joint stiffness than to the sheet thinning.}},
author = {{Martin, Sven and Bielak, Christian Roman and Bobbert, Mathias and Tröster, Thomas and Meschut, Gerson}},
issn = {{0944-6524}},
journal = {{Production Engineering}},
keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering}},
publisher = {{Springer Science and Business Media LLC}},
title = {{{Numerical investigation of the clinched joint loadings considering the initial pre-strain in the joining area}}},
doi = {{10.1007/s11740-021-01103-w}},
year = {{2022}},
}
@article{63829,
abstract = {{The 3D shear deformation and failure behaviour of a glass fibre reinforced polypropylene in a shear strain rate range of γ˙=2.2×10−4 to 3.4 1s is investigated. An Iosipescu testing setup on a servo-hydraulic high speed testing unit is used to experimentally characterise the in-plane and out-of-plane behaviour utilising three specimen configurations (12-, 13- and 31-direction). The experimental procedure as well as the testing results are presented and discussed. The measured shear stress–shear strain relations indicate a highly nonlinear behaviour and a distinct rate dependency. Two methods are investigated to derive according material characteristics: a classical engineering approach based on moduli and strengths and a data driven approach based on the curve progression. In all cases a Johnson–Cook based formulation is used to describe rate dependency. The analysis methodologies as well as the derived model parameters are described and discussed in detail. It is shown that a phenomenologically enhanced regression can be used to obtain material characteristics for a generalising constitutive model based on the data driven approach.}},
author = {{Gerritzen, Johannes and Hornig, Andreas and Gröger, Benjamin and Gude, Maik}},
issn = {{2504-477X}},
journal = {{Journal of Composites Science}},
number = {{10}},
publisher = {{MDPI AG}},
title = {{{A Data Driven Modelling Approach for the Strain Rate Dependent 3D Shear Deformation and Failure of Thermoplastic Fibre Reinforced Composites: Experimental Characterisation and Deriving Modelling Parameters}}},
doi = {{10.3390/jcs6100318}},
volume = {{6}},
year = {{2022}},
}
@article{36332,
abstract = {{AlSi casting alloys combine excellent castability with high strength. Hence, this group of alloys is often used in the automotive sector. The challenge for this application is the brittle character of these alloys which leads to cracks during joint formation when mechanical joining technologies are used. A rise in ductility can be achieved by a considerable increase in the solidification rate which results in grain refinement. High solidification rates can be realized in twin–roll casting (TRC) by water-cooled rolls. Therefore, a hypoeutectic EN AC–AlSi9 (for European Norm - aluminum cast product) is manufactured by the TRC process and analyzed. Subsequently, joining investigations are performed on castings in as-cast and heat-treated condition using the self-piercing riveting process considering the joint formation and the load-bearing capacity. Due to the fine microstructure, the crack initiation can be avoided during joining, while maintaining the joining parameters, especially by specimens in heat treatment conditions. Furthermore, due to the extremely fine microstructure, the load-bearing capacity of the joint can be significantly increased in terms of the maximum load-bearing force and the energy absorbed.}},
author = {{Neuser, Moritz and Kappe, Fabian and Ostermeier, Jakob and Krüger, Jan Tobias and Bobbert, Mathias and Meschut, Gerson and Schaper, Mirko and Grydin, Olexandr}},
issn = {{1438-1656}},
journal = {{Advanced Engineering Materials}},
keywords = {{Condensed Matter Physics, General Materials Science}},
number = {{10}},
publisher = {{Wiley}},
title = {{{Mechanical Properties and Joinability of AlSi9 Alloy Manufactured by Twin‐Roll Casting}}},
doi = {{10.1002/adem.202200874}},
volume = {{24}},
year = {{2022}},
}
@article{30963,
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, Lars and Bielak, Christian Roman and Otroshi, Mortaza and Bobbert, Mathias and Meschut, Gerson and Zimmermann, Martina}},
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{34069,
author = {{Schramm, Britta and Martin, Sven and Steinfelder, Christian and Bielak, Christian Roman and Brosius, Alexander and Meschut, Gerson and Tröster, Thomas and Wallmersperger, Thomas and Mergheim, Julia}},
issn = {{2666-3309}},
journal = {{Journal of Advanced Joining Processes}},
keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}},
publisher = {{Elsevier BV}},
title = {{{A Review on the Modeling of the Clinching Process Chain - Part I: Design Phase}}},
doi = {{10.1016/j.jajp.2022.100133}},
volume = {{6}},
year = {{2022}},
}
@article{34068,
author = {{Schramm, Britta and Friedlein, Johannes and Gröger, Benjamin and Bielak, Christian Roman and Bobbert, Mathias and Gude, Maik and Meschut, Gerson and Wallmersperger, Thomas and Mergheim, Julia}},
issn = {{2666-3309}},
journal = {{Journal of Advanced Joining Processes}},
keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}},
publisher = {{Elsevier BV}},
title = {{{A Review on the Modeling of the Clinching Process Chain - Part II: Joining Process}}},
doi = {{10.1016/j.jajp.2022.100134}},
year = {{2022}},
}
@article{34070,
author = {{Schramm, Britta and Harzheim, Sven and Weiß, Deborah and Joy, Tintu David and Hofmann, Martin and Mergheim, Julia and Wallmersperger, Thomas}},
issn = {{2666-3309}},
journal = {{Journal of Advanced Joining Processes}},
keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}},
publisher = {{Elsevier BV}},
title = {{{A Review on the Modeling of the Clinching Process Chain - Part III: Operational Phase}}},
doi = {{10.1016/j.jajp.2022.100135}},
year = {{2022}},
}
@article{31238,
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}},
year = {{2022}},
}
@inbook{29771,
author = {{Grydin, Olexandr and Mortensen, Dag and Neuser, Moritz and Lindholm, Dag and Fjaer, Hallvard G. and Schaper, Mirko}},
booktitle = {{Light Metals 2022}},
isbn = {{9783030925284}},
issn = {{2367-1181}},
publisher = {{Springer International Publishing}},
title = {{{Numerical and Experimental Investigation of Heat Transfer in the Solidification-Deformation Zone During Twin-Roll Casting of Aluminum Strips}}},
doi = {{10.1007/978-3-030-92529-1_96}},
year = {{2022}},
}
@article{30647,
abstract = {{The increasing economic and ecological demands on the mobility sector require efforts to reduce resource consumption in both the production and utilization phases. The use of lightweight construction technologies can save material and increase energy efficiency during operation. Multi-material systems consisting of different materials and geometries are used to achieve weight reduction. Since conventional joining processes reach their limits in the connection of these components, new methods and technologies are necessary in order to be able to react versatilely to varying process and disturbance variables. For fundamental investigations of new possibilities in joining technology, numerical investigations are helpful to identify process parameters. To generate valid results, robust and efficient material models are developed which are adapted to the requirements of versatile joining technologies, for instance to the high plastic strains associated with self-piercing riveting. To describe the inherent strain-induced plastic orthotropy of sheet metal an anisotropic Hill-plasticity model is formulated. Tensile tests for different sheet orientations are conducted both experimentally and numerically to adjust the anisotropic material parameters by inverse parameter identification for aluminium EN AW-6014 and steel HCT590X. Then, the layer compression test is used to validate the model and the previously identified parameters.}},
author = {{Friedlein, J. and Wituschek, S. and Lechner, M. and Mergheim, J. and Steinmann, P.}},
journal = {{IOP Conference Series: Materials Science and Engineering}},
pages = {{012004}},
title = {{{Inverse parameter identification of an anisotropic plasticity model for sheet metal}}},
doi = {{10.1088/1757-899X/1157/1/012004}},
volume = {{1157}},
year = {{2021}},
}
@article{30643,
abstract = {{The multi-material design and the adaptability of a modern process chain require joining connections with specifically adjustable mechanical, thermal, chemical, or electrical properties. Previous considerations primarily focused on the mechanical properties. The multitude of possible combinations of requirements, materials, and component- and joining-geometry makes an empirical determination of these joining properties for the clinching process impossible. Based on the established and empirical procedure, there is currently no model that takes into account all questions of joinability—i.e., the materials (suitability for joining), design (security of joining), and production (joining possibility)—that allows a calculation of the properties that can be achieved. It is therefore necessary to describe the physical properties of the joint as a function of the three binding mechanisms—form closure, force closure, and material closure—in relation to the application. This approach illustrates the relationships along the causal chain “joint requirement-binding mechanism-joining parameters” and improves the adaptability of the mechanical joining technology. Geometrical properties of clinch connections of the combination of aluminum and steel are compared in a metallographic cross-section. The mechanical stress state of the rotationally symmetrical clinch points is qualified with a torsion test and by measuring the electrical resistance in the base material, in the clinch joint, and during the production cycle (after clinching, before precipitation hardening and after precipitation hardening).}},
author = {{Kalich, J. and Füssel, U.}},
journal = {{Journal of Manufacturing and Materials Processing}},
pages = {{105}},
title = {{{Influence of the production process on the binding mechanism of clinched aluminum steel mixed compounds}}},
doi = {{10.3390/jmmp5040105}},
volume = {{5}},
year = {{2021}},
}
@article{30644,
abstract = {{Computational homogenization is a powerful tool allowing to obtain homogenized properties of materials on the macroscale from simulations of the underlying microstructure. The response of the microstructure is, however, strongly affected by variations in the microstructure geometry. In particular, we consider heterogeneous materials with randomly distributed non-overlapping inclusions, which radii are also random. In this work we extend the earlier proposed non-deterministic computational homogenization framework to plastic materials, thereby increasing the model versatility and overall realism. We apply novel soft periodic boundary conditions and estimate their effect in case of non-periodic material microstructures. We study macroscopic plasticity signatures like the macroscopic von-Mises stress and make useful conclusions for further constitutive modeling. Simulations demonstrate the effect of the novel boundary conditions, which significantly differ from the standard periodic boundary conditions, and the large influence of parameter variations and hence the importance of the stochastic modeling.}},
author = {{Pivovarov, D. and Mergheim, J. and Willner, K. and Steinmann, P.}},
journal = {{Computational Mechanics}},
title = {{{Stochastic local FEM for computational homogenization of heterogeneous materials exhibiting large plastic deformations}}},
doi = {{10.1007/s00466-021-02099-x}},
year = {{2021}},
}