@inproceedings{59483,
abstract = {{Abstract. The assessment of mechanically joined connections, such as clinched connections, is usually conducted destructively. Applicable non-destructive testing methods like computed tomography are time-consuming and costly, or, like electrical resistance measurement, provide only a limited amount of information. A fast, non-destructive evaluation of the joints condition shall be made possible by using transient dynamic analysis (TDA). It is based on the introduction of sound waves and the evaluation of the response behavior after passing through the structure. This study focuses the application of TDA to clinched shear connections to evaluate the performance of the tactile measuring setup. Twenty-one series were investigated, covering variations in joining task, manufacturing and defect. The evaluation was carried out using machine learning to determine for which series characteristic signals may be detected. It was shown that a classification of the investigated specimens is possible, whereby the classification accuracy depends on the examined variation. Furthermore, the accuracy was evaluated as a function of frequency and results were concluded to identify the limits of the used measuring setup.}},
author = {{Reschke, Gregor and Brosius, Alexander}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
keywords = {{Joining, Machine Learning, Transient Dynamic Analysis}},
location = {{Paderborn}},
pages = {{293--300}},
publisher = {{Materials Research Forum LLC}},
title = {{{Transient dynamic analysis: Performance evaluation of tactile measurement}}},
doi = {{10.21741/9781644903551-36}},
volume = {{52}},
year = {{2025}},
}
@inproceedings{59876,
abstract = {{Abstract. Clinching is a conventional mechanical joining process used in Multi-Material Design in the automotive sector. To receive the desired geometrical characteristics in clinch joints, correct process design is required. To reduce the cost of finding fitting process parameters, numerical simulation of the joining process can be used to predict the geometrical characteristics, such as interlock, instead of an experimental approach. These numerical simulation models consume computational resources and time. In this paper machine learning is used to find correlations between features of the joining process and geometrical characteristics in the joint. This serves the purpose of predicting the joint’s target values more resource-efficiently. Modelling with machine learning requires a structured dataset with sufficient parameter variation. To create this data base the following procedure was used. For joining partners, a HC340LA steel alloy with 2 mm material thickness was used punch-sided and an EN AW 5182 aluminum alloy with 1.5 mm thickness was used die-sided. For this combination a suitable tool combination and punch distance was experimentally identified. A finite element model was created to reproduce the joining process. For the modelling of the material of both joining partners flow curves determined by Vallaster et al. were used [1]. The punch and die were recreated digitally by opto-electronic measurements and transformed into a mesh suitable for numerical simulation. The model was validated by comparing process values like the maximum force applied by the punch and geometrical values in the joints cross section. Additionally, a process window for suitable punch distances was experimentally determined. Afterwards a variation of 70 different process designs was conducted with variants inside and outside the process window. The results were used for training, testing and validating various machine learning models. All models competed against each other to find the must suited model to predict every geometric value. To ensure good model performances and prevent the model from overfitting, a tenfold cross validation was used for validating the models. Analysis of the results gives the following key findings: i) Good predictability is reached for the interlock and sheet thickness of the joint. ii) Prediction neck thickness showed low error values, but also low correlation. iii)The prediction of those key values for evaluating clinch joint characteristics by machine learning models positively impacts needed resources in comparison to numerical models.}},
author = {{Ludwig, Jean-Patrick and Tsi-Nda Lontsi, Seraphin and Neumann, Jonas and Kappis, Lukas and Scharr, Christian and Flügge, Wilko and Merklein, Marion and Meschut, Gerson}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Data driven prognosis of clinch joints in multi-material design}}},
doi = {{10.21741/9781644903599-157}},
volume = {{54}},
year = {{2025}},
}
@inproceedings{59894,
abstract = {{Abstract. This study presents intrinsic lubrication as a novel approach to deep drawing processes, using additively manufactured, lubricant-permeable tools to minimize lubricant consumption and improve efficiency. Two systems were evaluated: a passive system based on capillary action and gravity, and an active system using pumped delivery for precise, on-demand application. Experimental tests were conducted on micro-bores (0.2-0.5 mm) to demonstrate their suitability for lubricant transport. Smaller bores have excellent capillary action but are prone to clogging, while larger bores offer higher permeability. The passive system is resource-efficient but requires adjustments to counteract gravitational asymmetry. The active system provides consistent lubricant distribution but is more complex. These findings provide a basis for optimizing intrinsic lubrication systems.}},
author = {{Cakici, Ermir and Homberg, Werner}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
location = {{Paestum, Italien}},
publisher = {{Materials Research Forum LLC}},
title = {{{Intrinsic lubrication: A new approach in the context of the deep drawing process}}},
doi = {{10.21741/9781644903599-122}},
volume = {{54}},
year = {{2025}},
}
@inproceedings{60108,
abstract = {{Abstract. In the field of mechanical engineering, destructive tests such as shear tests of mechanical joints are usually followed by imaging methods such as microsectioning or computed tomography (CT). They can help to interpret the measured load-displacement curves, analyze the failure behavior and validate numerical models. However, due to unloading, springback effects and crack closures can occur, which influence the state of the investigated specimen. In this context, in situ CT is able to explore the testing process with a specimen under load avoiding these influences. For in situ CT investigations, the displacement increase is interrupted at certain stop points. While the displacement is kept constant, the CT scan is performed. However, it was observed that the reaction force reduces during CT scanning, e. g. due to settling effects in the test setup. Although in situ CT is established now in research, little attention is paid to the uncertainties which arise from the discontinuous testing procedure. This study systematically explores the impact of these interruptions on the load-displacement behavior and the geometry of clinch points during tensile shear testing. To quantify the influence of the interruptions, loads at defined displacement levels and the final geometry are evaluated statistically. We found, that the load-displacement behavior of both test groups is similar. Despite some small but significant statistical deviations of the loads and the final geometry, our results show that, discontinuous testing has a high level of significance for the phenomena overserved in shear tests with clinch points.}},
author = {{Köhler, D. and Troschitz, J and Kupfer, R. and Gude, M.}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{In situ computed tomography – Analysis of settling effects during single-lap shear tests with clinch points}}},
doi = {{10.21741/9781644903551-15}},
volume = {{52}},
year = {{2025}},
}
@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{59587,
abstract = {{Abstract. As a widely used sheet metal in clinched joints within the automotive industry, the aluminum alloy EN AW-6014 has been the focus of numerous studies. High-cycle fatigue (HCF) is a critical aspect when assessing the durability of clinched joints. In the present work, the HCF behavior of EN AW-6014 T4 was explored both experimentally and numerically. To model the fatigue behavior, Lemaitre’s two-scale damage model was used. Two key parameters, damage strength and damage exponent, are necessary for numerical investigations of HCF behavior. These parameters were determined through experiments with flat specimens and subsequently validated within a numerical model of clinched joints. The numerical results for fatigue match the experimental ones of the clinched joints quite well.}},
author = {{Chen, Chin and Schlichter, Malte Christian and Harzheim, Sven and Hofmann, Martin and Bobbert, Mathias and Meschut, Gerson and Wallmersperger, Thomas}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{High-cycle fatigue testing and parameter identification for numerical simulation of aluminum alloy EN AW-6014}}},
doi = {{10.21741/9781644903551-23}},
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}},
}
@inproceedings{59441,
abstract = {{Abstract. Accurate Finite Element Modeling (FEM) of joints is essential in the design of complex mechanical systems such as automotive body-in-white (BIW) structures, as it plays a critical role in evaluating their performance. Although well-established techniques exist for modeling rotationally symmetric joints, there remains a significant gap in effectively modeling non-rotationally symmetric joints. These joints are particularly relevant in the automotive BIW, where they can better accommodate anisotropic loading conditions. In this study, strategies for modeling non-rotationally symmetric joints were explored using finite element simulations in LS-DYNA. The findings demonstrate that discrete beam elements can capture the anisotropic characteristics of such joints. Two models were tested: a single-beam model for stiffness periodicity every 90°, and a three-beam model for stiffness periodicity every 120°. Force responses, stress distribution, and sheet bending behaviors were analyzed, confirming that discrete beam elements can accurately represent direction-dependent stiffness. These results establish a foundation for developing advanced joint modeling strategies in complex mechanical systems.}},
author = {{Devulapally, Deekshith Reddy and Tröster, Thomas}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
location = {{Paderborn}},
publisher = {{Materials Research Forum LLC}},
title = {{{Modelling strategies for non-rotationally symmetric joints}}},
doi = {{10.21741/9781644903551-21}},
volume = {{52}},
year = {{2025}},
}
@inproceedings{59154,
abstract = {{Abstract. Lightweight design is one of the central topics of the automotive industry since reducing mass can save emissions over the entire life cycle of a component. Nowadays, vehicle structures usually consist of a multi-material design, which poses the additional challenge of joining these different materials. Mechanical joining is the most common way of joining different types of materials. Cast aluminium alloys of the AlSi system have a low ductility, which causes cracks during the mechanical joining process in the joint. One research approach is to achieve a fine microstructure by influencing the solidification rate since this results in increased mechanical properties, specifically the elongation at fracture and yield strength. A very fine microstructure can be achieved by utilizing Twin-roll casting (TRC) which is a continuous casting process in which high solidification rates of more than 100 K/s occur. In this study, the hypoeutectic cast aluminium alloy AlSi9 is processed in the TRC process using copper rollers. The cast strips are investigated regarding the microstructure-property correlation. A variation of the roller materials and cooling conditions allows for an increase in the solidification rate, whereby a defined, fine microstructure can be achieved, which enhances the mechanical properties of the hypoeutectic aluminium casting alloys.}},
author = {{Neuser, Moritz and Hoyer, Kay-Peter and Schaper, Mirko}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Processing of the hypoeutectic AlSi9 alloy with twin-roll casting by using copper shells}}},
doi = {{10.21741/9781644903551-26}},
volume = {{52}},
year = {{2025}},
}
@inproceedings{59155,
abstract = {{Abstract. Twin-Roll-Casting (TRC) is an energy- and cost-efficient process to produce near-net-shape aluminum strips. Due to the high affinity of molten aluminum to steel surfaces, those rollers show signs of wear throughout the rolling campaign. This leads to the necessity of restoring the worn surfaces to suitable parameters. The easiest way is to grind the surface till all superficial defects are omitted. However, the thickness of the roller is not endless, therefore the rollers must be replaced after a certain amount of surface reconditioning. This ultimately leads to the non-usability of the roller. This research shows a route to recondition the surface including the possibility of renewing worn-down surfaces with an energy- and cost-efficient high-velocity oxygen fuel (HVOF) treatment with subsequent grinding to the desired initial surface parameters.}},
author = {{Lauth, Martin and Hoyer, Kay-Peter and Schaper, Mirko and Gräfen, Winfried}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Cost-effective repair solution for twin-roll-caster rollers}}},
doi = {{10.21741/9781644903551-5}},
volume = {{52}},
year = {{2025}},
}
@inproceedings{60198,
abstract = {{Abstract. The growing significance of lightweight design, reveals drawbacks of conventional joining processes such as welding, which are known to consume a considerable amount of energy. This fosters the use of mechanical joining processes including clinching. However, the lack of universally applicable design methods results in a cost- and time-intensive design process. The utilization of machine learning methods can overcome these drawbacks. To ensure a reliable clinch joint design, inherent uncertainties of the design parameter such as tool deviations need to be considered in the design process. Varying distributions of design parameters, due to changes in the manufacturing process, can lead to high-computational effort in recalculating the resulting clinch joint properties with numerical simulations. Current metamodel-based methods for consideration of inherent uncertainties within the design parameters do not investigate the transferability of metamodels to different distributions of design parameters, which can lead to incorrect predictions. Therefore, this contribution investigates the performance of several metamodels on differently distributed design parameters. The obtained results indicate that metamodels demonstrate the best performance when training and evaluation distributions are identical and that polynomial regression models perform best on disparate distributions, when trained on uniform distributions.}},
author = {{Einwag, Jonathan-Markus and Mayer, Yannik and Goetz, Stefan and Wartzack, Sandro}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Impact of the parameter distribution on the predictive quality of metamodels for clinch joint properties}}},
doi = {{10.21741/9781644903551-35}},
volume = {{52}},
year = {{2025}},
}
@inproceedings{59485,
abstract = {{This paper focuses on the failure behavior of specimens with various configurations of clinched joints under shear tensile loading. The primary objective is to assess the influence of the joining direction and the spatial arrangement of clinched joints on their mechanical performance. A number of experiments was conducted, focusing on three clinched joints arranged in different configurations, each varying in terms of joining direction and spacing. These configurations were subjected to shear tensile tests, with force-displacement curves recorded for each sample to provide a detailed characterization of their structural response. The experimental findings indicate that the specific arrangement of the clinched joints, in terms of joining direction, has a marginal impact on the overall failure behavior. This suggests that intricate modifications to the joining direction are unnecessary to achieve improved mechanical performance in such applications. These results offer valuable insights for the design of clinched joint assemblies, indicating that simplified joining strategies may suffice without compromising structural integrity under shear loading.}},
author = {{Wolf, Eugen and Brosius, Alexander}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
keywords = {{Joining, Sheet Metal, Clinching}},
location = {{Paderborn}},
pages = {{ 86 -- 92}},
publisher = {{Materials Research Forum LLC}},
title = {{{Investigation failure behavior in the shear tensile test with respect to the arrangements of clinched joints}}},
doi = {{10.21741/9781644903551-11}},
volume = {{52}},
year = {{2025}},
}
@inproceedings{60290,
abstract = {{The constantly increasing demand for climate protection and resource conservation requires innovative and versatile joining processes that improve adaptability to the joining task and robustness to enable flexible manufacturing on a production line. Therefore, the versatile SPR (V-SPR) and tumbling SPR (T-SPR) were developed. Using the example of a mixed material combination HCT590X+Z (t0 = 1.0 mm) / EN AW-6014 T4 (t0 = 2.0 mm), these processes were examined and compared with regard to the binding mechanisms form closure and force closure using micrographs, non-destructive resistance measurements and destructive torsion tests. For this purpose, a new sample geometry was defined, and the methods were adapted to the SPR process variants.}},
author = {{Lüder, Stephan and Holtkamp, Pia Katharina and Wituschek, Simon and Bobbert, Mathias and Meschut, Gerson and Lechner, Michael and Schmale, Hans Christian}},
booktitle = {{Materials Research Proceedings}},
editor = {{Meschut, Gerson and Bobbert, Mathias and Duflou, Joost and Fratini, Livan and Hagenah, Hinnerk and Martins, Paulo A. F. and Merklein, Marion and Micari, Fabrizio}},
issn = {{2474-395X}},
keywords = {{Joining, Self-Piercing Riveting, Sheet Metal}},
location = {{Paderborn}},
pages = {{101 -- 108}},
publisher = {{Materials Research Forum LLC}},
title = {{{Analysis of the binding mechanisms depending on versatile process variants of self-piercing riveting}}},
doi = {{10.21741/9781644903551-13}},
volume = {{52}},
year = {{2025}},
}
@inproceedings{60439,
abstract = {{Abstract. Mechanical joints are traditionally analyzed through destructive micrograph analysis, which may compromise internal geometry and morphology, as evidenced by radial cracks in semi-tubular self-pierce riveting. In contrast, industrial X-ray computed tomography (XCT) offers a non-destructive method for component diagnosis, providing volumetric insights without damaging the sample and enabling dimensional measurement. The DFG-funded Collaborative Research Center TRR 285 is exploring XCT's application in assessing mechanical joinability across various joining processes and materials, particularly in multi-material systems like steel-aluminum joints. XCT faces challenges in accurately capturing multi-material compositions, leading to artifacts that complicate interface detection. This research aims to validate XCT for joint investigations, yielding quantitative characteristics that surpass those from traditional micrograph analysis.}},
author = {{Lechner, M. and Borgert, Thomas and Busch, Matthias and Harms, A. and Holtkamp, Pia Katharina and Römisch, D. and Wituschek, Simon and Kappe, Fabian}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Non-destructive testing in versatile joining processes}}},
doi = {{10.21741/9781644903551-12}},
volume = {{52}},
year = {{2025}},
}
@inproceedings{61174,
abstract = {{Abstract. Mechanical joining methods, such as clinching, are characterised by locally large plastic deformations of the sheet metal to be joined. The majority of the thereby inserted work is transformed into heat. The heat generation and temperature evolution are systematically studied herein by means of thermomechanical process simulations for joining the dual-phase steel HCT590X and the aluminium alloy EN-AW 6014. The thermal-induced softening of the material is incorporated by a suitable coupled thermoplastic constitutive model. It is observed how the tools significantly and importantly contribute to the heat exchange. They reduce peak temperature increases of 225 K (without heat transfer to tools) to less than 90 K for realistic behaviour of contact heat transfer. Overall, increases in temperature during clinch joining can be expected to remain below 90 K for steel-steel joints and around 50 K for aluminium-aluminium joints.}},
author = {{Friedlein, J. and Steinmann, P. and Mergheim, J.}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Influence of thermal effects on clinch joining of sheet metal}}},
doi = {{10.21741/9781644903551-22}},
volume = {{52}},
year = {{2025}},
}
@inproceedings{61835,
abstract = {{Abstract. Saving emissions and a circular economy are key aspects of sustainable production and compliance global climate change targets. Friction-induced solid-state recycling of aluminum scrap to production endless semi-finished products. Scrap is fed into a continuously rotating wheel. This requires less energy compared to heat-based recycling processes. Different sizes, shapes and surfaces of chips can be used as starting material in the process. The influence of this has been shown in past publications. A native oxide layer is a fixed component of aluminum surface. This layer is broken up during the forming process, allowing the aluminum to bond. In addition to the geometry, the surface finishes and the thickness of the oxide layer are therefore also important input variables in friction-induced solid-state recycling. The oxide layers on the chips were determined for the investigation. In addition, different layer thicknesses were produced to survey their influence. The resulting semi-finished products were evaluated on the basis of their tensile strength and microstructure. The main result of the investigations is the fact that semi-finished products made from chips with thicker oxide layers tend to be more brittle. In addition, thick oxide layers cause microstructural and surface defects.}},
author = {{Gabsa, Steffen}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Influence of different oxide thicknesses on the friction induced and continuous solid-state recycling of aluminum scrap}}},
doi = {{10.21741/9781644903599-272}},
volume = {{54}},
year = {{2025}},
}
@inproceedings{61763,
abstract = {{Abstract. Within the punch-bending process semi-finished products of strip or wire material are formed and punched in several subsequent steps into a finished product like brackets, mounts, contacts or spring elements. In the context of those multi-stage straightening and bending processes, cross-stage and quantity-dependent effects significantly leads to undesired component deviations. To optimize the punch-bending process with regard to these component deviations and thus the waste rate, the concept of a hybrid data-driven model is presented. To automatically acquire and process this hybrid data while also enable the usage by multiple clients, a digital twin has to be developed. In this paper the communication infrastructure between the punch-bending system and the digital twin is presented, using the Asset Administration Shell as specification. This automated communication is validated using exemplary data from the punch-bending system.}},
author = {{Peters, Henning and Mazur, Andreas and Trächtler, Ansgar and Hammer, Barbara}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
publisher = {{Materials Research Forum LLC}},
title = {{{Integration of a digital twin for data-driven modeling of punch-bending processes using the asset administration shell}}},
doi = {{10.21741/9781644903599-166}},
volume = {{54}},
year = {{2025}},
}