@article{41490,
author = {{Hein, Maxwell and Lopes Dias, Nelson Filipe and Kokalj, David and Stangier, Dominic and Hoyer, Kay-Peter and Tillmann, Wolfgang and Schaper, Mirko}},
issn = {{0142-1123}},
journal = {{International Journal of Fatigue}},
keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering, Mechanics of Materials, General Materials Science, Modeling and Simulation}},
publisher = {{Elsevier BV}},
title = {{{On the influence of physical vapor deposited thin coatings on the low-cycle fatigue behavior of additively processed Ti-6Al-7Nb alloy}}},
doi = {{10.1016/j.ijfatigue.2022.107235}},
volume = {{166}},
year = {{2022}},
}
@article{34000,
abstract = {{Abstract
This paper presents the characterization of the microstructure evolution during flow forming of austenitic stainless steel AISI 304L. Due to plastic deformation of metastable austenitic steel, phase transformation from γ-austenite into α’-martensite occurs. This is initiated by the formation of shear bands as product of the external stresses. By means of coupled microscopic and micromagnetic investigations, a characterization of the microstructure was carried out. In particular, this study shows the distribution of the strain-induced α’-martensite and its influence on material properties like hardness at different depths. The microstructural analyses by means of electron backscattered diffraction (EBSD) technique, evidence a higher amount of α’-martensite (ca. 23 %) close to the outer specimen surface, where the plastic deformation and the direct contact with the forming tool take place. In the middle area (ca. 1.5 mm depth from the outer surface), the portion of transformed α’-martensite drops to 7 % and in the inner surface to 2 %. These results are well correlated with microhardness and micromagnetic measurements at different depths. EBSD and atomic force microscopy (AFM) were used to make a detailed characterization of the topography and degree of deformation of the shear bands. Likewise, the mechanisms of nucleation of α’-martensite were discussed. This research contributes to the development of micromagnetic sensors to monitor the evolution of properties during flow forming. This makes them more suitable for closed-loop property control, which offers possibilities for an application-oriented and more efficient production.}},
author = {{Rozo Vasquez, Julian and Kanagarajah, Hanigah and Arian, Bahman and Kersting, Lukas and Homberg, Werner and Trächtler, Ansgar and Walther, Frank}},
issn = {{2195-8599}},
journal = {{Practical Metallography}},
keywords = {{Metals and Alloys, Mechanics of Materials, Condensed Matter Physics, Electronic, Optical and Magnetic Materials}},
number = {{11}},
pages = {{660--675}},
publisher = {{Walter de Gruyter GmbH}},
title = {{{Coupled microscopic and micromagnetic depth-specific analysis of plastic deformation and phase transformation of metastable austenitic steel AISI 304L by flow forming}}},
doi = {{10.1515/pm-2022-0064}},
volume = {{59}},
year = {{2022}},
}
@article{33999,
abstract = {{The production of complex multi-functional, high-strength parts is becoming increasingly important in the industry. Especially with small batch size, the incremental flow forming processes can be advantageous. The production of parts with complex geometry and locally graded material properties currently depicts a great challenge in the flow forming process. At this point, the usage of closed-loop control for the shape and properties could be a feasible new solution. The overall aim in this project is to establish an intelligent closed-loop control system for the wall thickness as well as the α’-martensite content of AISI 304L-workpieces in a flow forming process. To reach this goal, a novel sensor concept for online measurements of the wall thickness reduction and the martensite content during forming process is proposed. It includes the setup of a modified flow forming machine and the integration of the sensor system in the machine control. Additionally, a simulation model for the flow forming process is presented which describes the forming process with regard to the plastic workpiece deformation, the induced α’-martensite fraction, and the sensor behavior. This model was used for designing a closed-loop process control of the wall thickness reduction that was subsequently realized at the real plant including online measured feedback from the sensor system.}},
author = {{Kersting, Lukas and Arian, Bahman and Vasquez, Julian Rozo and Trächtler, Ansgar and Homberg, Werner and Walther, Frank}},
issn = {{1662-9795}},
journal = {{Key Engineering Materials}},
keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
pages = {{862--874}},
publisher = {{Trans Tech Publications, Ltd.}},
title = {{{Innovative Online Measurement and Modelling Approach for Property-Controlled Flow Forming Processes}}},
doi = {{10.4028/p-yp2hj3}},
volume = {{926}},
year = {{2022}},
}
@article{32869,
abstract = {{The further development of in-mold-assembly (IMA) technologies for structural hybrid components is of great importance for increasing the economic efficiency and thus the application potential. This paper presents an innovative IMA process concept for the manufacturing of bending loaded hybrid components consisting of two outer metal belts and an inner core structure made of glass mat reinforced thermoplastic (GMT). In this process, the core structure, which is provided with stiffening ribs and functional elements, is formed and joined to two metal belts in one single step. For experimental validation of the concept, the development of a prototypic molding tool and the manufacturing of hybrid beams including process parameters are described. Three-point bending tests and optical measurement technologies are used to characterize the failure behavior and mechanical properties of the produced hybrid beams. It was found that the innovative IMA process enables the manufacturing of hybrid components with high energy absorption and low weight in one step. The mass-specific energy absorption is increased by 693 % compared to pure GMT beams.}},
author = {{Stallmeister, Tim and Tröster, Thomas}},
issn = {{1662-9795}},
journal = {{Key Engineering Materials}},
keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
pages = {{1457--1467}},
publisher = {{Trans Tech Publications, Ltd.}},
title = {{{In-Mold-Assembly of Hybrid Bending Structures by Compression Molding}}},
doi = {{10.4028/p-5fxp53}},
volume = {{926}},
year = {{2022}},
}
@article{32068,
abstract = {{Inspired by plant grafting, grafted vortex beams can be formed through grafting two or more helical phase profiles of optical vortex beams. Recently, grafted perfect vortex beams (GPVBs) have attracted much attention due to their unique optical properties and potential applications. However, the current method to generate and manipulate GPVBs requires a complex and bulky optical system, hindering further investigation and limiting its practical applications. Here, a compact metasurface approach for generating and manipulating GPVBs in multiple channels is proposed and demonstrated, which eliminates the need for such a complex optical setup. A single metasurface is utilized to realize various superpositions of GPVBs with different combinations of topological charges in four channels, leading to asymmetric singularity distributions. The positions of singularities in the superimposed beam can be further modulated by introducing an initial phase difference in the metasurface design. The work demonstrates a compact metasurface platform that performs a sophisticated optical task that is very challenging with conventional optics, opening opportunities for the investigation and applications of GPVBs in a wide range of emerging application areas, such as singular optics and quantum science.}},
author = {{Ahmed, Hammad and Intaravanne, Yuttana and Ming, Yang and Ansari, Muhammad Afnan and Buller, Gerald S. and Zentgraf, Thomas and Chen, Xianzhong}},
issn = {{0935-9648}},
journal = {{Advanced Materials}},
keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
number = {{30}},
publisher = {{Wiley}},
title = {{{Multichannel Superposition of Grafted Perfect Vortex Beams}}},
doi = {{10.1002/adma.202203044}},
volume = {{34}},
year = {{2022}},
}
@article{39412,
abstract = {{ The Eringen’s nonlocal elastica equation does not possess a Lagrangian formulation. In this article, we find a variational integrating factor which enables us to provide a Lagrangian and Hamiltonian structure associated to this equation. Explicit expressions of the solutions in terms of elliptic integrals of the first kind are then deduced. We then derive discrete version of the Eringen’s nonlocal elastica preserving the Lagrangian and Hamiltonian structure and compare it with Challamel’s and co-worker definition of a discrete Eringen’s nonlocal elastica. }},
author = {{Cresson, Jacky and Hariz-Belgacem, Khaled}},
issn = {{1081-2865}},
journal = {{Mathematics and Mechanics of Solids}},
keywords = {{Mechanics of Materials, General Materials Science, General Mathematics}},
publisher = {{SAGE Publications}},
title = {{{About the structure of the discrete and continuous Eringen’s nonlocal elastica}}},
doi = {{10.1177/10812865221108094}},
year = {{2022}},
}
@article{39400,
abstract = {{ The Eringen’s nonlocal elastica equation does not possess a Lagrangian formulation. In this article, we find a variational integrating factor which enables us to provide a Lagrangian and Hamiltonian structure associated to this equation. Explicit expressions of the solutions in terms of elliptic integrals of the first kind are then deduced. We then derive discrete version of the Eringen’s nonlocal elastica preserving the Lagrangian and Hamiltonian structure and compare it with Challamel’s and co-worker definition of a discrete Eringen’s nonlocal elastica. }},
author = {{Cresson, Jacky and Hariz Belgacem, Khaled}},
issn = {{1081-2865}},
journal = {{Mathematics and Mechanics of Solids}},
keywords = {{Mechanics of Materials, General Materials Science, General Mathematics}},
publisher = {{SAGE Publications}},
title = {{{About the structure of the discrete and continuous Eringen’s nonlocal elastica}}},
doi = {{10.1177/10812865221108094}},
year = {{2022}},
}
@article{29790,
abstract = {{The free exciton transition (near-band-edge emission, NBE) of ZnO at ≈388 nm can be strongly enhanced and even stimulated by an underlying photonic structure. 1D Photonic crystals, so-called distributed Bragg reflectors, are utilized to suppress the deep-level emission of ZnO (DLE, ≈500–530 nm). The reflector stacks are fabricated in a layer-by-layer procedure by wet-chemical synthesis. They consist of low-ε porous SiO2 layers and high-ε TiO2 layers. Varying the thickness of the SiO2 layers allows tuning the optical bandgap in a wide range between ≈420 and 800 nm. A ZnO layer is deposited on top of the reflector stacks by sol–gel synthesis. The spontaneous photoluminescence (PL) emission of the ZnO film is modulated by the photonic structure. When the optical bandgap of the reflector is in resonance with the deep-level emission of ZnO (DLE, ≈500–530 nm), then this defect-related emission mode is suppressed. Strong NBE emission is observed even when the ZnO layer does not show any NBE emission (due to low crystallinity) in the absence of the photonic structure. With this cost-efficient synthesis method, emitters for, e.g., luminescent gas sensors can be fabricated.}},
author = {{Kothe, Linda and Albert, Maximilian and Meier, Cedrik and Wagner, Thorsten and Tiemann, Michael}},
issn = {{2196-7350}},
journal = {{Advanced Materials Interfaces}},
keywords = {{Mechanical Engineering, Mechanics of Materials}},
publisher = {{Wiley}},
title = {{{Stimulation and Enhancement of Near‐Band‐Edge Emission in Zinc Oxide by Distributed Bragg Reflectors}}},
doi = {{10.1002/admi.202102357}},
volume = {{9}},
year = {{2022}},
}
@article{51197,
abstract = {{Clinching is a cost efficient method for joining components in series production. To assure the clinch point’s quality, the force displacement curve during clinching or the bottom thickness are monitored. The most significant geometrical characteristics of the clinch point, neck thickness and undercut, are usually tested destructively by microsectioning. However, micrograph preparation goes ahead with a resetting of elastic deformations and crack-closing after unloading. To generate a comprehensive knowledge of the clinch point’s inner geometry under load, in-situ computed tomography (CT) and acoustic testing (TDA) can be combined. While the TDA is highly sensitive to the inner state of the clinch point, it could detect critical events like crack development during loading. If such events are indicated, the loading process is stopped and a stepped in-situ CT of the following crack and deformation development is performed. In this paper, the concept is applied to the process of clinching itself, providing a detailed three-dimensional insight in the development of the joining zone. A test set-up is used which allows a stepwise clinching of two aluminium sheets EN AW 6014. Furthermore, this set-up is positioned within a CT system. In order to minimize X-ray absorption, a beryllium cylinder is used within the set-up frame and clinching tools are made from Si3N4. The actuator and sensor necessary for the TDA are integrated in the set-up. In regular process steps, the clinching process is interrupted in order to perform a TDA and a CT scan. In order to enhance the visibility of the interface, a thin tin layer is positioned between the sheets prior clinching. It is shown, that the test-set up allows a monitoring of the dynamic behaviour of the specimen during clinching while the CT scans visualize the inner geometry and material flow non-destructively.}},
author = {{Köhler, Daniel and Stephan, Richard and Kupfer, Robert and Troschitz, Juliane and Brosius, Alexander and Gude, Maik}},
issn = {{1662-9795}},
journal = {{Key Engineering Materials}},
keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
pages = {{1489--1497}},
publisher = {{Trans Tech Publications, Ltd.}},
title = {{{Investigations on Combined <i>In Situ</i> CT and Acoustic Analysis during Clinching}}},
doi = {{10.4028/p-32330d}},
volume = {{926}},
year = {{2022}},
}
@article{51193,
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{51196,
author = {{Meschut, G. and Merklein, M. and Brosius, A. and Drummer, D. and Fratini, L. and Füssel, U. and Gude, M. and Homberg, W. and Martins, P.A.F. and Bobbert, M. and Lechner, M. and Kupfer, R. and Gröger, B. and Han, D. and Kalich, J. and Kappe, F. and Kleffel, T. and Köhler, D. and Kuball, C.-M. and Popp, J. and Römisch, D. and Troschitz, J. and Wischer, C. 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{33687,
author = {{Odziomek, Mateusz and Giusto, Paolo and Kossmann, Janina and Tarakina, Nadezda V. and Heske, Julian Joachim and Rivadeneira, Salvador M. and Keil, Waldemar and Schmidt, Claudia and Mazzanti, Stefano and Savateev, Oleksandr and Perdigón‐Toro, Lorena and Neher, Dieter and Kühne, Thomas and Antonietti, Markus and López‐Salas, Nieves}},
issn = {{0935-9648}},
journal = {{Advanced Materials}},
keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
number = {{40}},
publisher = {{Wiley}},
title = {{{“Red Carbon”: A Rediscovered Covalent Crystalline Semiconductor}}},
doi = {{10.1002/adma.202206405}},
volume = {{34}},
year = {{2022}},
}
@article{52612,
abstract = {{During resistance spot welding of zinc-coated advanced high-strength steels (AHSSs) for automotive production, liquid metal embrittlement (LME) cracking may occur in the event of a combination of various unfavorable influences. In this study, the interactions of different welding current levels and weld times on the tendency for LME cracking in third-generation AHSSs were investigated. LME manifested itself as high-penetration cracks around the circumference of the spot welds for welding currents closely below the expulsion limit. At the same time, the observed tendency for LME cracking showed no direct correlation with the overall heat input of the investigated welding processes. To identify a reliable indicator of the tendency for LME cracking, the local strain rate at the origin of the observed cracks was analyzed over the course of the welding process via finite element simulation. While the local strain rate showed a good correlation with the process-specific LME cracking tendency, it was difficult to interpret due to its discontinuous course. Therefore, based on the experimental measurement of electrode displacement during welding, electrode indentation velocity was proposed as a descriptive indicator for quantifying cracking tendency.}},
author = {{Böhne, Christoph and Meschut, Gerson and BIEGLER, MAX and RETHMEIER, MICHAEL}},
issn = {{0043-2296}},
journal = {{Welding Journal}},
keywords = {{Metals and Alloys, Mechanical Engineering, Mechanics of Materials}},
number = {{7}},
pages = {{197--207}},
publisher = {{American Welding Society}},
title = {{{The Influence of Electrode Indentation Rate on LME Formation during RSW}}},
doi = {{10.29391/2022.101.015}},
volume = {{101}},
year = {{2022}},
}
@article{37647,
abstract = {{Mechanical joining processes are an essential part of modern lightweight construction. They permit materials of different types to be joined in a way that is suitable for the loads involved. These processes reach their limits, however, as soon as the boundary conditions change. In most cases, these elements are specially adapted to the joining point and cannot be used universally. Changes require cost-intensive adaptation of both the element and the process control, thus making production more complex. This results in high costs due to the increased number of auxiliary joining element variants required and reduces the economic efficiency of mechanical joining. One approach to overcoming this issue is the use of adaptive auxiliary joining elements formed by friction spinning. This article presents the current state of research on pre-hole-free joining with adaptive joining elements. The overall process chain is illustrated, explained and analyzed. Special attention is paid to demonstrating the feasibility of pre-hole-free joining with adaptive joining elements. The chosen mechanical parameters are subsequently listed. Finally, a comprehensive outlook of the future development potential is derived.}},
author = {{Wischer, Christian and Homberg, Werner}},
issn = {{1662-9795}},
journal = {{Key Engineering Materials}},
keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
pages = {{1468--1478}},
publisher = {{Trans Tech Publications, Ltd.}},
title = {{{Further Development of an Adaptive Joining Technique Based on Friction Spinning to Produce Pre-Hole-Free Joints}}},
doi = {{10.4028/p-1n6741}},
volume = {{926}},
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}},
}
@article{33657,
author = {{Mirhosseini, Hossein and Tahmasbi, Hossein and Kuchana, Sai Ram and Ghasemi, Alireza and Kühne, Thomas}},
issn = {{0927-0256}},
journal = {{Computational Materials Science}},
keywords = {{Computational Mathematics, General Physics and Astronomy, Mechanics of Materials, General Materials Science, General Chemistry, General Computer Science}},
publisher = {{Elsevier BV}},
title = {{{An automated approach for developing neural network interatomic potentials with FLAME}}},
doi = {{10.1016/j.commatsci.2021.110567}},
volume = {{197}},
year = {{2021}},
}
@article{34227,
abstract = {{In order to reduce the fuel consumption and consequently the greenhouse emissions, the automotive industry is implementing lightweight constructions in the body in white production. As a result, the use of aluminum alloys is continuously increasing. Due to poor weldability of aluminum in combination with other materials, mechanical joining technologies like clinching are increasingly used. In order to predict relevant characteristics of clinched joints and to ensure the reliability of the process, it is simulated numerically during product development processes. In this regard the predictive accuracy of the simulated process highly depends on the implemented friction model. In particular, the frictional behavior between the sheet metals affects the geometrical formation of the clinched joint significantly. This paper presents a testing method, which enables to determine the frictional coefficients between sheet metal materials for the simulation of clinching processes. For this purpose, the correlation of interface pressure and the relative velocity between aluminum sheets in clinching processes is investigated using numerical simulation. Furthermore, the developed testing method focuses on the specimen geometry as well as the reproduction of the occurring friction conditions between two sheet metal materials in clinching processes. Based on a methodical approach the test setup is explained and the functionality of the method is proven by experimental tests using sheet metal material EN AW6014.}},
author = {{Rossel, Moritz Sebastian and Böhnke, Max and Bielak, Christian Roman and Bobbert, Mathias and Meschut, Gerson}},
issn = {{1662-9795}},
journal = {{Key Engineering Materials}},
keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}},
pages = {{81--88}},
publisher = {{Trans Tech Publications, Ltd.}},
title = {{{Development of a Method for the Identification of Friction Coefficients in Sheet Metal Materials for the Numerical Simulation of Clinching Processes}}},
doi = {{10.4028/www.scientific.net/kem.883.81}},
volume = {{883}},
year = {{2021}},
}