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Prof. Dr.-Ing. Gerson Meschut

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Prof. Dr.-Ing. Gerson Meschut

Werkstoff- und Fügetechnik

Leiter - Professor - Lehrstuhlverantwortlicher

Institut für Leichtbau mit Hybridsystemen (ILH)

Vorstand - Professor - Vorstand ILH

Telefon:
+49 5251 60-3031
Fax:
+49 5251 60-3239
Büro:
P1.4.11.1
Web:
Besucher:
Pohlweg 47-49
33098 Paderborn

Sonderforschungsbereich Transregio 285

Sprecher - Professor - Teilprojekte A01, C02, Z

Telefon:
+49 5251 60 3031
Fax:
+49 5251 60 3239

Liste im Research Information System öffnen

2023

Optimization of inductive fast-curing of epoxy adhesive by model-based kinetics

J. Kowatz, D. Teutenberg, G. Meschut, International Journal of Adhesion and Adhesives (2023)


Flexible Automation through Robot-Assisted Mechanical Joining in Small Batches

S. Neumann, J. Wippermann, G. Meschut, M. Stepputat, F. Beuss, W. Flügge, 2023


Mechanically Joined Extrusion Profiles for Battery Trays

S. Neumann, G. Meschut, M. Otroshi, F. Kneuper, A. Schulze, E. Tekkaya, 2023


Thermal influence of resistance spot welding on a nearby overmolded thermoplastic–metal joint

J. Wippermann, G. Meschut, W. Koschukow, A. Liebsch, M. Gude, S. Minch, B. Kolbe, Welding in the World (2023)

DOI


2022

Methodology for the systematic investigation of the hygrothermal-mechanical behavior of a structural epoxy adhesive

S. Sander, G. Meschut, U. Kroll, A. Matzenmiller, International Journal of Adhesion and Adhesives (2022), 103072

DOI


Methodenentwicklung zur Versagensanalyse aufgrund der Aushärtung vorgeschädigter Klebverbindungen in stahlintensiven Mischbaustrukturen

F. Beule, D. Teutenberg, G. Meschut, T. Aubel, A. Matzenmiller. Methodenentwicklung zur Versagensanalyse aufgrund der Aushärtung vorgeschädigter Klebverbindungen in stahlintensiven Mischbaustrukturen. 2022.


Lebensdauerprognose für Stahlklebverbindungen bei multiaxialer Belastung mit Phasenverschiebung, veränderlicher Mittelspannung und variablen Amplituden

V. Carillo Beber, C. Nagel, B. Mayer, C. Köster, A. Matzenmiller, M. Hecht, J. Baumgartner, T. Melz, K. Tews, S. Çavdar, G. Meschut, in: 22. Kolloquium: Gemeinsame Forschung in der Klebtechnik, 2022


Methodenentwicklung zur numerischen Lebensdauerprognose von hyperelastischen Klebverbindungen infolge zyklischer Beanspruchung mittels bruchmechanischer Ansätze

K. Tews, T. Aubel, D. Teutenberg, G. Meschut, T. Duffe, G. Kullmer, in: 22. Kolloquium: Gemeinsame Forschung in der Klebtechnik, 2022


DigiBody - Digitale Prozesskette zur Abbildung und Optimierung der Fügetechnik im Rohbau

S. Jamei, N. Döller, S. Lossau, F. Beule, M. Al Trjman, T. Aubel, G. Meschut, D. Sommer, S. Facciotto, A. Droste, A. Haufe, M. Helbig, H. Gleich, K. Kose. DigiBody - Digitale Prozesskette zur Abbildung und Optimierung der Fügetechnik im Rohbau . 2022.



Analyse des Versagensverhaltens geklebter Stahl-Verbindungen beim werkstoffschonenden Entfügen in der Karosserieinstandsetzung

N. Chudalla, G. Meschut, A. Bartley, T.M. Wibbeke, in: 22. Kolloquium: Gemeinsame Forschung in der Klebtechnik, 2022


Methodenentwicklung für die Simulation mechanischer Fügeprozesse mit besonderer Berücksichtigung fügespezifischer Reibverhältnisse

M.S. Rossel, G. Meschut, Europäische Forschungsgesellschaft für Blechverarbeitung e.V., 2022, pp. 180



Experimentelle und numerische Untersuchung des Einflusses variabler Betriebstemperaturen auf das Trag- und Versagensverhalten struktureller Klebverbindungen unter Crashbelastung

M. Striewe, G. Meschut, L. Schmelzle, J. Mergheim, G. Possart, P. Steinmann. Experimentelle und numerische Untersuchung des Einflusses variabler Betriebstemperaturen auf das Trag- und Versagensverhalten struktureller Klebverbindungen unter Crashbelastung. 2022.


Increasing the accuracy of clinching process simulations by modeling the friction as a function of local joining process parameters

M.S. Rossel, G. Meschut, Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications (2022), 146442072210742

<jats:p> In this study, an innovative friction model is used to improve the quality of clinching process simulations. Consequently, the future over dimensioning can be reduced. Furthermore, the improved prediction quality of the joining process simulation leads to an improvement in the simulation of load-bearing capacity as well. In this way, the entire sampling process can be performed virtually without any experimental investigations. This will contribute to the advancement of lightweight construction in the automotive industry. In this work, the frictional behavior is studied in dependence on the local joining process parameters. As a reference for the numerical investigations, clinch joints by means of a die with fixed geometry are joined. Additionally, a hardness mapping is performed on the microsection of the clinch joints. It shows the local strain hardening, which correlates with the forming degree in the simulation. Based on the occurring contacts and the local joining process parameters in the joining process simulation, the test matrix for the experimental friction tests is defined. The friction tests are carried out on a compression-torsion-tribometer. This type of tribometer is able to apply high interface pressures above the initial yield stress due to the specimen encapsulation. Besides, the pure joining part contact, the contact between the joining part and joining tool can be tested as well. The experimental test setup offers the possibility to evaluate the influences of temperature, relative velocity, interface pressure, and frictional stroke independently. Based on the results of the experimental friction tests, a friction model is created. The resulting friction model is integrated into the numerical joining process simulation via a subroutine. To validate the quality of the new friction modeling, the results of simulations are compared with the experiments in terms of load-stroke diagrams, joint geometry, and hardness mappings on the microsection. </jats:p>


Process-adapted temperature application within a two-stage rivet forming process for high nitrogen steel

C. Kuball, B. Uhe, G. Meschut, M. Merklein, Proceedings of the Institution of Mechanical Engineers Part L-Journal of Materials-Design and Applications (2022), pp. 1-17

DOI


Investigation of the friction conditions of self-pierce rivets by means of a compression-torsion tribometer

M.S. Rossel, G. Meschut, Production Engineering (2022)

Lightweight design is an effective lever for achieving fuel consumption and emission-oriented goals. Therefore micro-alloyed steels and high-strength aluminium materials are included in the multi-material mix of the car body. In this context self-pierce riveting has become established for joining in body-in-white production. For the dimensioning of the joint, numerical simulation is increasingly being used. In order to make reliable predictions about joint quality, knowledge of the friction in the joining process is necessary and needs to be identified experimentally. In previous investigations, the process parameters in the friction test were not comparable to the joining process. Therefore, a new friction test method is presented in this paper, where the process conditions are comparable between joining and friction testing especially regarding the interface pressure. The local joining process parameters between rivet and sheet are derived numerically. In the framework of the investigations, the influences of the local joining process parameters, like interface pressure, relative velocity and temperature, on the friction are investigated and mapped close to the joining process. Additionally a comparison of different rivet coatings is carried out. The rivet contact to the sheet metal HX340LAD as well with aluminium EN AW-5182 is taken into account.


Influence of cutting clearance and punch geometry on the stress state in small punch test

M. Otroshi, G. Meschut, Engineering Failure Analysis (2022), 136(c)

The presented paper aims to characterize the damage and fracture behavior of HX340LAD Micro-Alloyed steels using small punch test. Variations with respect to punch geometries and cutting clearance are made to describe the damage behavior of the material under different loading conditions. Experimental investigations are conducted to identify the crack initiation in the specimens. Furthermore, the numerical FEM simulations are performed to identify the stress state at crack initiation. It is shown that different stress states from shear to biaxial tension can be achieved by changing the geometries of punch and varying the cutting clearance. Moreover, it is presented how changing the configurations can influence the stress state variables: Triaxiality and lode angle parameter.


Systematisierung einer rechnergestützten Auswertemethode zur Versagensanalyse geklebter Verbindungen

N. Chudalla, D. Teutenberg, G. Meschut, M. Schneider, D. Smart, in: 22. Kolloquium: Gemeinsame Forschung in der Klebtechnik, 2022


Development of a rivet geometry for solid self-piercing riveting of thermally loaded CFRP-metal joints in automotive construction

J. Vorderbrüggen, D. Köhler, B. Grüber, J. Troschitz, M. Gude, G. Meschut, Composite Structures (2022), 291, 115583

DOI


Consideration of the manufacturing history of sheet metal components for the adaptation of a clinching process

P. Heyser, S. Wiesenmayer, P. Frey, T. Nehls, C. Scharr, W. Flügge, M. Merklein, G. Meschut, Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications (2022), 146442072210775

The process chain for the manufacturing of sheet metal components in mass production includes various cutting and forming operations, which influence the resulting properties of the parts and therefore subsequent manufacturing steps, such as clamping and joining. It is shown that clamping of the components leads to superimposed residual stresses and geometry changes. Therefore, the part properties differ from the initial state of the semifinished products, which has to be considered in the design of clinched joints. This paper presents an approach for coupled determination of the properties of semifinished and finished parts during deep drawing and clamping as well as their effects on the joint quality during clinching. One method for the effective and efficient determination of the properties of semifinished products and components during production is using process data from the preceding manufacturing processes, which is concretely presented in this work. In addition to the interconnection of the entire production chain, it is necessary to define relevant process data for each individual manufacturing step and to correlate the data with the material properties reliably. Therefore, the cross-process interactions of different steps of the process chain for the manufacturing of sheet metal components and the effect of process variations on subsequent manufacturing steps are investigated. Consequently, the boundary conditions for a mechanical joining process based on data from preceding process steps can be predicted.


Provision of cross-domain knowledge in mechanical joining using ontologies

C. Zirngibl, P. Kügler, J. Popp, C.R. Bielak, M. Bobbert, D. Drummer, G. Meschut, S. Wartzack, B. Schleich, Production Engineering (2022)

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.</jats:p>


Numerical and experimental identification of fatigue crack initiation sites in clinched joints

L. Ewenz, C.R. Bielak, M. Otroshi, M. Bobbert, G. Meschut, M. Zimmermann, Production Engineering (2022), 16(2-3), pp. 305-313

<jats:title>Abstract</jats:title><jats:p>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.</jats:p>


Bauteilschonendes Entfügen struktureller Klebverbindungen durch Kälte

N. Chudalla, G. Meschut, A. Bartley, T.M. Wibbeke, adhäsion KLEBEN &amp; DICHTEN (2022), 66(4), pp. 34-37

DOI


Influence of curing-induced pre-deformations on the mechanical properties of adhesively bonded joints in steel-intensive mixed-material structures

F. Beule, D. Teutenberg, G. Meschut, T. Aubel, A. Matzenmiller. Influence of curing-induced pre-deformations on the mechanical properties of adhesively bonded joints in steel-intensive mixed-material structures. 2022.


Investigation of leak tightness for bonded steel joints induced by mechanical and corrosive load for use in battery housings

T. Schmolke, G. Meschut. Investigation of leak tightness for bonded steel joints induced by mechanical and corrosive load for use in battery housings. 2022.


Untersuchung von Klebverbindungen für Batteriegehäuse

T. Schmolke, G. Meschut, F. Rieker, D. Meinderink, G. Grundmeier, adhäsion KLEBEN & DICHTEN (2022), 66, pp. 40-43

DOI


Disjoining and repair strategies of structural joints in automotive lightweight structures

N. Chudalla, A. Bartley, J. Ditter, G. Meschut, T.M. Wibbeke, 2022



A Review on the Modeling of the Clinching Process Chain - Part II: Joining Process

B. Schramm, J. Friedlein, B. Gröger, C.R. Bielak, M. Bobbert, M. Gude, G. Meschut, T. Wallmersperger, J. Mergheim, Journal of Advanced Joining Processes (2022), 100134

DOI



Schädigungsmodellierung von Hilfsfügeelementen beim mechanischen Fügen von Stahlwerkstoffen

M. Otroshi, G. Meschut. Schädigungsmodellierung von Hilfsfügeelementen beim mechanischen Fügen von Stahlwerkstoffen. 2022.


Review on mechanical joining by plastic deformation

G. Meschut, M. Merklein, A. Brosius, D. Drummer, L. Fratini, U. Füssel, M. Gude, W. Homberg, P. Martins, M. Bobbert, M. Lechner, R. Kupfer, B. Gröger, D. Han, J. Kalich, F. Kappe, T. Kleffel, D. Köhler, C. Kuball, J. Popp, D. Römisch, J. Troschitz, C. Wischer, S. Wituschek, M. Wolf, Journal of Advanced Joining Processes (2022), 5, 100113

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.


Development of a Numerical 3D Model for Analyzing Clinched Joints in Versatile Process Chains

C.R. Bielak, M. Böhnke, M. Bobbert, G. Meschut, in: The Minerals, Metals &amp; Materials Series, Springer International Publishing, 2022

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.


Numerical and experimental identification of fatigue crack initiation sites in clinched joints

L. Ewenz, C.R. Bielak, M. Otroshi, M. Bobbert, G. Meschut, M. Zimmermann, Production Engineering (2022), 16(2-3), pp. 305-313

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.


Thermal influence of resistance spot welding on nearby overmoulded plastic metal joints

J. Wippermann, G. Meschut, W. Koschukow, A. Liebsch, M. Gude, B. Kolbe, S. Minch. Thermal influence of resistance spot welding on nearby overmoulded plastic metal joints. 2022.


Flexible Teilautomatisierung des robotergestützten mechanischen Fügens

J. Wippermann, G. Meschut, M. Stepputat, W. Flügge. Flexible Teilautomatisierung des robotergestützten mechanischen Fügens. 2022.


Numerical investigation of the clinched joint loadings considering the initial pre-strain in the joining area

S. Martin, C.R. Bielak, M. Bobbert, T. Tröster, G. Meschut, Production Engineering (2022)

<jats:title>Abstract</jats:title><jats:p>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.</jats:p>


Numerical investigation of a friction test to determine the friction coefficients for the clinching process

C.R. Bielak, M. Böhnke, M. Bobbert, G. Meschut, Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications (2022), 146442072210934

<jats:p> 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. </jats:p>


Increasing flexibility of self-piercing riveting by reducing tool–geometry combinations using cluster analysis in the application of multi-material design

F. Kappe, L. Schadow, M. Bobbert, G. Meschut, Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications (2022)

DOI


Determining the properties of multi‑range semi‑tubular self‑piercing riveted joints

F. Kappe, S. Wituschek, M. Bobbert, G. Meschut, Production Engineering (2022)

DOI


Weight-optimized Battery Housings for Volume Vehicles

T. Schmolke, C. Krüger, D. Merdivan, G. Meschut, ATZ worldwide (2022), 124(1), pp. 66-71

DOI


Methodenentwicklung zur rechnerischen Auslegung geklebter Stahlverbindungen unter Alterungsbeanspruchung im Stahl- und Anlagenbau

S. Sander, D. Teutenberg, G. Meschut, F. Kötz, A. Matzenmiller, Y. Kasper, T. Ummenhofer, in: 22. Kolloquium Gemeinsame Forschung in der Klebtechnik, 2022


Gewichtsoptimierte Batteriegehäuse für Volumenfahrzeuge

T. Schmolke, C. Krüger, D. Merdivan, G. Meschut, ATZ - Automobiltechnische Zeitschrift (2022), 124(1), pp. 80-85

DOI


Metamodellbasierte Prozesskette - Umformen-Schneiden-Spannen-Fügen

P. Heyser, G. Meschut, T. Nehls, C. Scharr, P. Froitzheim, W. Flügge, S. Wiesenmayer, M. Merklein, in: Pressen, Systeme, Prozesse der Zukunft Effizienz + Digitalisierung, Europäische Forschungsgesellschaft für Blechverarbeitung e.V., 2022


Konzeption einer adaptiven Prozesskette für das mechanische Fügen

G. Meschut, P. Heyser, M. Merklein, S. Wiesenmayer, W. Flügge, C. Scharr, T. Nehls, Europäische Forschungsgesellschaft für Blechverarbeitung e.V, 2022


Smart process chain – data analysis in sheet metal processing for joinability prediction

P. Heyser, S. Wiesenmayer, T. Nehls, C. Scharr, W. Flügge, M. Merklein, G. Meschut, in: SMART PRODUCTION 2022: DIGITALIZING AUTOMOTIVE MANUFACTURING, Automotive Circle, 2022


Stress-based fatigue lifetime prediction of adhesively bonded joints with hyperelastic deformation behavior

S. Çavdar, G. Meschut, in: 45th Annual Meeting of The Adhesion Society, 2022


Fracture mechanical concept to predict crack nucleation in elastic adhesive joints

T. Duffe, K. Tews, G. Kullmer, G. Meschut. Fracture mechanical concept to predict crack nucleation in elastic adhesive joints. 2022.


Numerische Lebensdauerprognose von hyperelastischen Klebverbindungen mit einem bruchmechanischen Ansatz

T. Duffe, K. Tews, T. Aubel, G. Meschut, G. Kullmer, Fachzeitschrift für Schweißen und verwandte Verfahren (2022), 74(9), pp. 570-576


Investigation of the three-dimensional stress state during loading of self-piercing riveted joints

M. Otroshi, G. Meschut. Investigation of the three-dimensional stress state during loading of self-piercing riveted joints. 2022.



Numerical investigation of the influence of a movable die base on joint formation in semi-tubular self-piercing riveting

F. Kappe, S. Wituschek, V. de Pascalis, M. Bobbert, M. Lechner, G. Meschut, in: Materials Design and Application IV, Springer, 2022, pp. 137-149


Numerical Investigation of the Influence of a Movable Die Base on Joint Formation in Semi-tubular Self-piercing Riveting

F. Kappe, S. Wituschek, V. de Pascalis, M. Bobbert, M. Lechner, G. Meschut, in: Materials Design and Applications IV, Springer International Publishing, 2022

Due to economic and ecological requirements and the associated trend towards lightweight construction, mechanical joining technologies like self-piercing riveting are gaining in importance. In addition, the increase in lightweight multi-material joints has led to the development of many different mechanical joining technologies which can only be applied to join a small number of material combinations. This leads to low process efficiency, and in the case of self-piercing riveting, to a large number of required tool changes. Another approach focuses on reacting to changing boundary conditions as well as the creation of customised joints by using adaptive tools, versatile auxiliary joining parts or modified process kinematics. Therefore, this study investigates the influence of increased die-sided kinematics on joint formation in self-piercing riveting process. The aim is to achieve an improvement of the joint properties by superimposing the punch feed. Furthermore, it is intended to reduce required tool changes due to the improved joint design. The investigations were carried out by means of a 2D-axisymmetric numerical simulation model using the LS-Dyna simulation software. After the validation of the process model, the die was extended to include driven die elements. Using the model, different kinematics as well as their effects on the joint formation and the internal stress concentration could be analysed. In principle, the increased actuator technology enabled an increase of the interlock formation for both pure aluminium and multi-material joints consisting of steel and aluminium. However, the resulting process forces were higher during the process phases of punching and spreading.


Efficient debonding of adhesively bonded joints in car body repair

N. Chudalla, G. Meschut, A. Bartley, M. Wibbeke, 2022


A Review on the Modeling of the Clinching Process Chain - Part I: Design Phase

B. Schramm, S. Martin, C. Steinfelder, C.R. Bielak, A. Brosius, G. Meschut, T. Tröster, T. Wallmersperger, J. Mergheim, Journal of Advanced Joining Processes (2022), 6, 100133

DOI


Development of a crash behaviour prediction method for resistance spot welded 3-steel sheet joints

V. Olfert, G. Meschut, D. Hein, L. Schuster, S. Sommer, SCT, 2022

The recent trend towards extensive electric mobility leads to a variety of new challenges for the engineering of future vehicle concepts. One particular challenge is the additional weight added to the vehicle by the battery, which stands in direct contrast to the existing customer expectation of a high driving range. The reduction of the total vehicle weight is driven by the extensive use of ultra-high-strength steels in thin sheet thicknesses in car body construction. Resistance spot welding is the dominant joining process in steel-intensive lightweight construction due to its high degree of automation, process reliability and the associated economic efficiency. In order to comply limitations of the space in the vehicle body and to ensure the most efficient use of materials in lightweight construction, joints are used that connect several sheets with a single spot weld. This leads to new challenges for the prediction of the load-bearing capacity and failure behaviour under crash loading. This paper presents a systematic characterisation of 3 sheet steel joints in order to find formulary, empirical relationships between the load-bearing capacity of the joint and the affecting parameters. Numerical simulations are carried out in order to clarify the causes of occurring phenomena in experiments. For this purpose, influencing variables such as joint strength, joint arrangement, sheet thickness, sheet strength, load type and load case on the load bearing capacity and failure behaviour are identified. Furthermore, the extent to which the behaviour of 2-sheet joints can be transferred to 3-sheet joints is investigated. A formulary correlation enables a quick and inexpensive estimates of the load-bearing capacity of 3-sheet metal connections. These models can be used for a computer-efficient simulation of components with three layered spot welded joints.


Experimental and Numerical Investigation on Manufacturing-Induced Pre-Strain on the Load-Bearing Capacity of Clinched Joints

C.R. Bielak, M. Böhnke, M. Bobbert, G. Meschut, Key Engineering Materials (2022), 926, pp. 1516-1526

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.</jats:p>


Mechanical Properties and Joinability of AlSi9 Alloy Manufactured by Twin‐Roll Casting

M. Neuser, F. Kappe, J. Ostermeier, J.T. Krüger, M. Bobbert, G. Meschut, M. Schaper, O. Grydin, Advanced Engineering Materials (2022), 24(10), 2200874

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.


Directional dependence of the mechanical properties of structural adhesive joints with curing-induced pre-deformations

F. Beule, D. Teutenberg, G. Meschut, Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering (2022), 095440702211001

<jats:p> Owing to the implementation of multi-material construction methods in modern lightweight construction and the associated use of adhesive bonding technology, thermally induced relative displacements of the joining partners occur during the curing process. The resulting extremely complex thermo-chemo-mechanical stresses can influence the properties of the adhesive layers and reduce the load-bearing capacity. In this study, experiments are conducted to examine the influence of process-related thermal relative displacements on the mechanical properties of adhesives. The results show an anisotropy of the mechanical properties of the pre-deformed adhesive layers, depending on the magnitude and direction of the relative displacement. </jats:p>


Fatigue strength of adhesively butt-bonded hollow cylinders under multiaxial loading with constant and variable amplitudes

M. Hecht, J. Baumgartner, K. Tews, S. Çavdar, G. Meschut, Procedia Structural Integrity (2022), 38, pp. 251-259

DOI


Global energy release rate of small penny-shaped cracks in hyperelastic materials under general stress conditions

T. Duffe, G. Kullmer, K. Tews, T. Aubel, G. Meschut, Theoretical and Applied Fracture Mechanics (2022)

DOI


Functionality Study of an Optical Measurement Concept for Local Force Signal Determination in High Strain Rate Tensile Tests

M. Böhnke, E. Unruh, S. Sell, M. Bobbert, D. Hein, G. Meschut, Key Engineering Materials (2022), 926, pp. 1564-1572

<jats:p>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.</jats:p>


Influence of heat treatment on the suitability for clinching of the aluminium casting alloy AlSi9

M. Neuser, M. Böhnke, O. Grydin, M. Bobbert, M. Schaper, G. Meschut, Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications (2022), 146442072210758

<jats:p> In many manufacturing areas, multi-material designs are implemented in which individual components are joined together to form complex structures with numerous joints. For example, in the automotive sector, cast components are used at the junctions of the body and joined with different types of sheet metal and extruded profiles. To be able to join structures consisting of different materials, alternative joining technologies have emerged in recent years. This includes clinching, which allows assembling of two or more thin sheet metal and casting parts by solely cold forming the material. Clinching the brittle and usually less ductile cast aluminium alloys remains a challenge because the brittle character of the cast aluminium alloys can cause cracks during the forming of the clinched joint. In this study, the influence of the heat treatment time of an aluminium casting alloy AlSi9 on the joinability in the clinching process is investigated. Specific heat treatment of the naturally hard AlSi9 leads to a modification of the eutectic microstructure, which can increase ductility. Based on this, it will be examined if specific clinching die geometries can be used, which achieve an optimized geometrical formation of the clinched joint. The load-bearing capacities of the clinched joints are determined and compared by shear tensile and head tensile tests. Furthermore, the joints are examined microscopically to investigate the influence of the heat treatment on the failure behaviour during the load-bearing tests as well as crack initiation within the joining process. </jats:p>


Development of a Modified Punch Test for Investigating the Failure Behavior in Sheet Metal Materials

M. Böhnke, C.R. Bielak, M. Bobbert, G. Meschut, in: The Minerals, Metals &amp; Materials Series, Springer International Publishing, 2022

DOI


Experimental and numerical investigation of the influence of multiaxial loading conditions on the failure behavior of clinched joints

M. Böhnke, C.R. Bielak, M. Bobbert, G. Meschut, Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications (2022)

DOI


Development of a test method for investigating the leak tightness of hybrid joined battery housing connections

T. Schmolke, D. Teutenberg, G. Meschut, International Journal of Adhesion and Adhesives (2022), 117, 103171

DOI


MECHANICALLY JOINED EXTRUSION PROFILES FOR BATTERY TRAYS

S. Neumann, G. Meschut, M. Otroshi, F. Kneuper, A. Schulze, E. Tekkaya, 2022


Testing, modelling, and parameter identification for adhesively bonded joints under the influence of temperature

L. Schmelzle, M. Striewe, J. Mergheim, G. Meschut, G. Possart, D. Teutenberg, D. Hein, P. Steinmann, Journal of Adhesion Science and Technology (2022)

DOI


Robotergestütztes manuelles mechanisches Fügen – RoboterFügen

S. Neumann, G. Meschut, F. Schmatz, W. Flügge, 2022


2021

Dämpfungseigenschaften geklebter Verbindungen - Potenzialanalyse und Klebstoffcharakterisierung

J. Göddecke, G. Meschut, J. Damm, M. Albiez, T. Ummenhofer, adhäsion KLEBEN & DICHTEN (2021), pp. 14-23

DOI



Fiber response to pin penetration in dry woven fabric using numerical analysis

M. Droß, P. Heyser, G. Meschut, A. Hürkamp, K. Dröder, Journal of Advanced Joining Processes (2021), 100083


Mechanisches Fügen von FKV-FKV-Verbindungen

D. Han, G. Meschut, 2021

Within the scope of the research project, four new mechanical joining processes for the singlestage, pre-hole-free joining of FRP-FRP joints were further developed. For this purpose, the joining processes under consideration were first implemented on existing equipment at the research institute. Based on the successful adaptation of the joining processes, characteristics of the joints were documented by means of micrographs and observation of external characteristics, on the basis of which measures for process modification were derived. The process modifications were carried out on a process-specific basis for a selected GFRPGFRP joint. The aim was to improve the joint quality, in particular with regard to the reduction of laminate damage, by means of targeted element and tool development in addition to the increase in process stability. Based on these results, a realistic suitability evaluation of the joining methods was carried out with regard to process and manufacturing flexibility. As a result, two self-piercing riveting processes, which showed the greatest suitability potential, were examined in more detail to analyse the application limits. In the process, the joints were sampled on further material combinations with varied fibre and matrix systems. In addition, joints with adhesive were investigated, in which the influence of the adhesive viscosity on the joint properties was analysed. The joint properties of the new joining method were then comprehensively determined by tensile tests under quasi-static, cyclic loads. Finally, the behaviour of the optimised joints under corrosive load was characterised in the salt spray test. Through the targeted process modifications in this project, the FRP-FRP joints can be joined with less damage, enabling improved joint quality in the FRP-based components.


Effect of low-profile additives on the durability of adhesively bonded Sheet Moulding Compound (SMC)

V. Aßmuth, G. Meschut, International Journal of Adhesion and Adhesives (2021), 112, 103036

DOI


Konzeptentwicklung für ein Stahlbatteriegehäuse

T. Schmolke, G. Meschut, stahl. (2021), 3-4 / 2021, pp. 37-39


Modeling of adhesives in crash simulation under consideration of manufacturing processes

M. Helbig, A. Haufe, F. Beule, T. Aubel, G. Meschut, S. Jamei, F. Fürle, S. Lossau, A. Droste, H. Gleich, K. Kose, D. Sommer, S. Facciotto. Modeling of adhesives in crash simulation under consideration of manufacturing processes. 2021.


DigiBody - Optimizing of Joining Technology

M. Helbig, A. Haufe, F. Beule, T. Aubel, G. Meschut, S. Jamei, F. Fürle, S. Lossau, A. Droste, H. Gleich, K. Kose, D. Sommer, S. Facciotto. DigiBody - Optimizing of Joining Technology. 2021.



Analyse des Versagensverhaltens geklebter Stahl Verbindungen beim werkstoffschonenden Entfügen in der Karosserieinstandsetzung

N. Chudalla, G. Meschut, A. Bartley, T.M. Wibbeke. Analyse des Versagensverhaltens geklebter Stahl Verbindungen beim werkstoffschonenden Entfügen in der Karosserieinstandsetzung. 2021.


Joining of ultra-high-strength steels using resistance element welding on conventional resistance spot welding guns

H. Günter, G. Meschut, Welding in the World (2021)

DOI


Joining of press-hardened profiles for the mixed-intensive lightweight structural design in electric vehicles

H. Günter, G. Meschut, D. Fuss, K. Werner, M. Bangel, D. Rotzsche, M. Uffelmann, N. Oleff, in: Joining in Car Body Engineering 2021, 2021


Analyse rezepturabhängiger und alterungsbedingter Enthaftungserscheinungen geklebter SMC-Bauteile

V. Aßmuth, D. Teutenberg, G. Meschut, in: 10. Doktorandenseminar Klebtechnik, DVS Media GmbH, 2021


Development of an adaptive, sensor-based FDS-robot-system

M. Ivanjko, R. Beck, G. Meschut, J. Zweck, T. Richter, 2021



Influence of the Rivet Coating on the Friction during Self-Piercing Riveting

B. Uhe, C. Kuball, M. Merklein, G. Meschut, Key Engineering Materials (2021), 883, pp. 11-18

The number of multi-material joints is increasing as a result of lightweight design. Self-piercing riveting (SPR) is an important mechanical joining technique for multi-material structures. Rivets for SPR are coated to prevent corrosion, but this coating also influences the friction that prevails during the joining process. The aim of the present investigation is to evaluate this influence. The investigation focuses on the common rivet coatings Almac® and zinc-nickel with topcoat as well as on uncoated rivet surfaces. First of all, the coating thickness and the uniformity of the coating distribution are analysed. Friction tests facilitate the classification of the surface properties. The influence of the friction on the characteristic joint parameters and the force-stroke curves is analysed by means of experimental joining tests. More in-depth knowledge of the effects that occur is achieved through the use of numerical simulation. Overall, it is shown that the surface condition of the rivet has an impact on the friction during the joining process and on the resulting joint. However, the detected deviations between different surface conditions do not restrict the operational capability of SPR and the properties of uncoated rivet surfaces, in particular, are similar to those of Almac®-coated rivets. It can thus be assumed that SPR with respect to the joining process is also possible without rivet coating in principle.


Strength of self-piercing riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel

B. Uhe, C. Kuball, M. Merklein, G. Meschut, 2021

The use of high-strength steel and aluminium is rising due to the intensified efforts being made in lightweight design, and self-piercing riveting is becoming increasingly important. Conventional rivets for self-piercing riveting differ in their geometry, the material used, the condition of the material and the coating. To shorten the manufacturing process, the use of stainless steel with high strain hardening as the rivet material represents a promising approach. This allows the coating of the rivets to be omitted due to the corrosion resistance of the material and, since the strength of the stainless steel is achieved by cold forming, heat treatment is no longer required. In addition, it is possible to adjust the local strength within the rivet. Because of that, the authors have elaborated a concept for using high nitrogen steel 1.3815 as the rivet material. The present investigation focusses on the joint strength in order to evaluate the capability of rivets in high nitrogen steel by comparison to conventional rivets made of treatable steel. Due to certain challenges in the forming process of the high nitrogen steel rivets, deviations result from the targeted rivet geometry. Mainly these deviations cause a lower joint strength with these rivets, which is, however, adequate. All in all, the capability of the new rivet is proven by the results of this investigation.


Reduzierung der Flanschbreiten beim Widerstandspunktschweißen durch Einsatz exzentrischer Elektrodenkappengeometrien

C. Böhne, G. Tümkaya, G. Meschut. Reduzierung der Flanschbreiten beim Widerstandspunktschweißen durch Einsatz exzentrischer Elektrodenkappengeometrien. 2021.




Joining of press-hardened profiles for the mixed-intensive lightweight structural design in electric vehicles

D. Rotzsche, G. Meschut, D. Fuss, M. Bangel, M. Uffelmann, K. Werner, N. Oleff, H. Günter, in: Joining in Car Body Engineering 2021, 2021


Entwicklung einer gewichtsoptimierten Batteriegehäusestruktur für Volumenfahrzeuge

T. Schmolke, C. Krüger, D. Merdivan, S. Spohr, G. Meschut, Forschungsvereinigung Automobiltechnik (FAT) , 2021


Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening

B. Uhe, C. Kuball, M. Merklein, G. Meschut, in: Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series., Springer, 2021, pp. 1495-1506

Self-piercing riveting is an established technique for joining multi-material structures in car body manufacturing. Rivets for self-piercing riveting differ in their geometry, the material used, the condition of the material and their surface condition. To shorten the manufacturing process by omitting the heat treatment and the coating process, the authors have elaborated a concept for the use of stainless steel with high strain hardening as a rivet material. The focus of the present investigation is on the evaluation of the influences of the rivet’s geometry and material on its deformation behaviour. Conventional rivets of types P and HD2, a rivet with an improved geometry made of treatable steel 38B2, and rivets made of the stainless steels 1.3815 and 1.4541 are examined. The analysis is conducted by means of multi-step joining tests for two material combinations comprising high-strength steel HCT70X and aluminium EN AW-5083. The joints are cut to provide a cross-section and the deformation behaviour of the different rivets is analysed on the basis of the measured changes in geometry and hardness. In parallel, an examination of the force-stroke curves provides further insights. It can be demonstrated that, besides the geometry, the material strength, in particular, has a significant influence on the deformation behaviour of the rivet. The strength of steel 1.4541 is seen to be too low for the joining task, while the strength of steel 1.3815 is sufficient, and hence the investigation confirms the capability of rivets made of 1.3815 for joining even challenging material combinations.


A method for three-dimensional modelling of the shear-clinching process

D. Han, C. Yang, G. Meschut, ESAFORM 2021 (2021)

<jats:p>Three-dimensional modelling enables to determine the in-plane material flow in asymmetrical situation. Thus, the distortion of the sheets to be joined can be characterized more exactly. This study shows a method for building up a three-dimensional shear-clinching framework without damage criteria. In fact, the die-sided sheet in shear-clinching was designed as a pre-punched sheet and slugs. The material separation in the die-sided joining partner, which in two-dimensional simulation is often described by macro- and micromechanical fracture criteria, was realised in this study based on a defined contact condition. By means of a shear-cutting simulation, a correlation between the break angle and the separation stress was determined, which was used as a separation criterion in the shear-clinching simulation. The separation line was confirmed using post-particles. To validate this model, the results of the simulation using a quadratic single-point specimen were compared to the experiments with respect to the distortion of the joining partner. In general, the built three-dimensional framework provides for further tool developments with regard to the reduction of distortion in shear-clinching.</jats:p>





Intrinsische Hybridverbunde für Leichtbautragstrukturen

S. Sander, M. Bobbert, G. Meschut, Springer Vieweg, 2021, pp. 332


Mechanical joining of glass fibre reinforced polymer (GFRP) through an innovative solid self-piercing rivet

D. Han, K. Yang, G. Meschut, Journal of Materials Processing Technology (2021), 117182

DOI


Methodenentwicklung zur Versagensanalyse aufgrund der Aushärtung vorgeschädigter Klebverbindungen in stahlintensiven Mischbaustrukturen

F. Beule, D. Teutenberg, G. Meschut, T. Aubel, A. Matzenmiller. Methodenentwicklung zur Versagensanalyse aufgrund der Aushärtung vorgeschädigter Klebverbindungen in stahlintensiven Mischbaustrukturen. 2021.


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Prof. Dr.-Ing. Gerson Meschut

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