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Simulation Winter Conference

作者： Moritz Poeting Bastian Prell Markus Rabe Tobias Uhlig Sigrid Wenzel Institute of Transport Logistics TU Dortmund University Dortmund GERMANY Department Factory of the Future Fraunhofer Institute for Machine Tools and Forming Technology IWU Chemnitz GERMANY Department IT in Production and Logistics TU Dortmund University Dortmund GERMANY Department of Computer Science Universität der Bundeswehr München Neubiberg GERMANY Department of Organization of Production and Factory Planning University of Kassel Kassel GERMANY

ISBN: (数字)9781728132839

ISBN: (纸本)9781728120522

Traditionally, aspects such as emissions and energy consumption have to be taken into account for environmental and economic reasons when it comes to transport. In other areas of logistics, such as production logistics and intralogistics, the energy aspect is also becoming increasingly important. Existing literature has been recently reviewed in a contribution of the Arbeitsgemeinschaft Simulation (ASIM) to the Winter Simulation Conference 2018 (Uhlig et al. 2018) to develop a map of common approaches and best practices for manufacturing and logistics systems. In the paper presented here, as a complement we are focusing on the application of energy simulation in logistics to give a comprehensive overview and present exemplary case studies. Furthermore, we show a classification of approaches to combine energy aspects with simulation. Finally, we will discuss open questions and future trends in this field of research.

关键词： tools Mathematical model Supply chains Matlab Adaptation models

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Process optimization for flexible self-pierce riveting of multi-material structures

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AIP Conference Proceedings 2019年第1期2113卷

作者： Tobias Falk Mathias Jäckel 1Fraunhofer Institute for Machine Tools and Forming Technology IWU Nöthnitzer Straße 44 01187 Dresden Germany

One of the most important mechanical joining technologies for mixed-material car body constructions is self-pierce riveting with semi-tubular rivet (SPR-ST). In order to achieve appropriate joint quality for SPR-ST, it is often necessary to use individual process parameters like die geometry or rivet length for each material and thickness combination. In this paper a method is presented, that allows to increase the flexibility of the SPR-ST process by an optimization of process parameters in regard to join several material combinations with one die geometry. Thereby FEM simulation is combined with statistical approaches to develop an optimized SPR-ST process.

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A New Systematic Approach to the Description of Processes and their Classification

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Procedia Manufacturing 2017年 8卷 199-206页

作者： Alexandr, P. Kuznetsov Hans-Joachim, Koriath Moscow State University of Technology “STANKIN” Moscow 127055 Russian Federation Fraunhofer Institute for Machine Tools and Forming Technology IWU Chemnitz 09126 Germany

Technical systems change their states and relations between elements during the transformation of energy, matter and information. Paper develops a new systematic approach to the description of processes and their classification, completed by a general description of systems. Systemic transformation categories of typical processes are proposed and applied for an energetic-informational model. Functional relations between categories, transformations and parameters of processes are developed for their classification and digital evaluation. The number of processes that may be formed by the elements of the system is determined by the number of combinations. The proposed general energy-information model of manufacturing processes and new classification will initiate progressive research and development activities on manufacturing processes and associated technologies, the evaluation of increased technological competitiveness, the strategic trend scouting, the optimization of manufacturing processes. © 2017 The Authors

关键词： energy information machine manufacturing matter process

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Parameter Measurement and Conductive Heating During Press Hardening by Hot Metal Gas forming

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IOP Conference Series: Materials Science and Engineering 2019年第1期651卷

作者： M Bach L Degenkolb F Reuther V Psyk R Mauermann M Werner Fraunhofer Institute for Machine Tools and Forming Technology IWU Chemnitz Germany Salzgitter Hydroforming GmbH & Co. KG Crimmitschau Germany

Press hardening of steels for the production of car body components is very common. The reason for this is that the process allows the use of blanks with low wall thickness and the production of ultra-high strength components with complex geometries. The Hot Metal Gas forming (HMGF) process for closed profiles combines the advantages of hydroforming, such as increased rigidity, functional integration or elimination of joining operations, with those of press hardening. In this paper results of continuous tests with actively cooled tools are presented in combination with temperature and displacement measurement. Furthermore, test results for HMGF with tool integrated conductive heating are demonstrated. Tests were done with tube material PHS1800 by SSAB, part temperatures over the Point of austenitisation and maximum internal pressure of 70 MPa. Thermocouples recorded the heat distribution in the tools. Other measured and recorded variables were the displacement of the component wall while forming under increasing internal pressure by a tactile displacement sensor and simultaneous temperature of its surface with a thermal sensor head. For the first time, information on pressure, the corresponding deformation stage and temperature profile could be documented during an entire forming step. A close to series production geometry DP4 was used to investigate the tool-integrated conductive heating of components.

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Technologies for the mechanical joining of aluminum die castings

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AIP Conference Proceedings 2019年第1期2113卷

作者： Thomas Grimm Mathias Jäckel Tobias Falk Welf-Guntram Drossel 1Fraunhofer Institute for Machine Tools and Forming Technology IWU Nöthnitzer Straße 44 01187 Dresden Germany

This paper shows a comparison of existing self-pierce riveting technologies with the newly developed self-pierce riveting with solid formable rivet (SPR-SF) for the joining of Aluminum die casts. The challenges during the mechanical joining of the Aluminum die cast AlSi9Mn by different joining technologies like self-pierce riveting with semi-tubular rivet (SPR-ST), self-pierce riveting with moveable die element and semi-tubular rivet (S-SPR-ST), self-pierce riveting with solid rivet (SPR-S) and self-pierce riveting with solid formable rivet (SPR-SF) will be discussed and the joining technologies in regard to process force, interlock, shear tensile strength and top tensile strength will be analyzed.

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Influence of an external applied AC magnetic field on the melt pool dynamics at high-power laser beam welding

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IOP Conference Series: Materials Science and Engineering 2021年第1期1135卷

作者： Ömer Üstündağ Nasim Bakir Andrey Gumenyuk Michael Rethmeier Bundesanstalt für Materialforschung und -prüfung (BAM) Unter den Eichen 87 12205 Berlin Germany Fraunhofer Institute for Production Systems and Design Technology Pascalstraße 8-9 10587 Berlin Germany Institute for Machine Tools and Factory Management Technische Universität Berlin Pascalstraße 8-9 10587 Berlin Germany

The study deals with the determination of the influence of an externally applied oscillating magnetic field on the melt pool dynamics in high power laser beam and hybrid laser arc welding processes. An AC magnet was positioned under the workpiece which is generating an upward directed electromagnetic force to counteract the formation of the droplets. To visualise the melt flow characteristics, several experiments were carried out using a special technique with mild steel from S355J2 with a plate thickness of up to 20 mm and a quartz glass in butt configuration. The profile of the keyhole and the melt flow were recorded with a highspeed camera from the glass side. Additionally, the influence of the magnetic field orientation to the welding direction on the filler material dilution on laser hybrid welding was studied with variating oscillation frequency. The element distribution over the whole seam thickness was measured with X-ray fluorescence (XRF). The oscillation frequency demonstrated a great influence on the melt pool dynamics and the mixing of the elements of the filler wire. The highspeed recordings showed, under the influence of the magnetic field, that the melt is affected under strong vortex at the weld root, which also avoids the formation of droplets.

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The bulging effect and its relevance in high power laser beam welding

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IOP Conference Series: Materials Science and Engineering 2021年第1期1135卷

作者： Antoni Artinov Xiangmeng Meng Nasim Bakir Ömer Üstündağ Marcel Bachmann Andrey Gumenyuk Michael Rethmeier Bundesanstalt für Materialforschung und -prüfung (BAM) Unter den Eichen 87 12205 Berlin Germany Fraunhofer Institute for Production Systems and Design Technology Pascalstraße 8-9 10587 Berlin Germany Institute for Machine Tools and Factory Management Technische Universität Berlin Pascalstraße 8-9 10587 Berlin Germany

The present work deals with the recently confirmed widening of the weld pool interface, known as a bulging effect, and its relevance in high power laser beam welding. A combined experimental and numerical approach is utilized to study the influence of the bulge on the hot cracking formation and the transport of alloying elements in the molten pool. A technique using a quartz glass, a direct-diode laser illumination, a high-speed camera, and an infrared camera is applied to visualize the weld pool geometry in the longitudinal section. The study examines the relevance of the bulging effect on both, partial and complete penetration, as well as for different sheet thicknesses ranging from 8 mm to 25 mm. The numerical analysis shows that the formation of a bulge region is highly dependent on the penetration depth and occurs more frequently during partial penetration above 6 mm and complete penetration above 8 mm penetration depth, respectively. The location of the bulge correlates strongly with the cracking location. The obtained experimental and numerical results reveal that the bulging effect increases the hot cracking susceptibility and limits the transfer of alloying elements from the top of the weld pool to the weld root.

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Investigation of the gap bridgeability at high-power laser hybrid welding of plasma-cut thick mild steels with AC magnetic support

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Journal of Physics: Conference Series 2021年第1期2077卷

作者： Ömer Üstündag Nasim Bakir Andrey Gumenyuk Michael Rethmeier Bundesanstalt für Materialforschung und -prüfung (BAM) Unter den Eichen 87 12205 Berlin Germany Fraunhofer Institute for Production Systems and Design Technology Pascalstraße 8-9 10587 Berlin Germany Institute of Machine Tools and Factory Management Technische Universität Berlin Pascalstraße 8-9 10587 Berlin Germany

One of the challenges of the high-power hybrid laser welding of thick steels is the sensitivity of the process of the process to manufacturing tolerances. This usually leads to a time-consuming preparation of the welding edges, such as milling. The study deals with the influence of the edge quality of milled and plasma-cut steel made of S355J2 with a wall thickness of 20 mm on the laser hybrid welded seam quality. Furthermore, the gap bridgeability and the tolerances towards edge misalignment was investigated. An AC magnet was used as backing support to prevent sagging and positioned under the workpiece, to generate an upwards directed electromagnetic pressure. The profiles of the edges and the gap on the top and root side were measured using a digital camera. Single-pass laser hybrid welds of plasma-cut edges could be welded using a laser beam power of just 13.7 kW. A gap bridgeability up to 2 mm and misalignment of edges up to 2 mm could be achieved successful. Additionally, the independence of the cutting side and the welding side was shown, so that samples were welded to the opposite side to their cutting. For evaluation of internal defects or irregularities, X-ray images were carried out. Charpy impact strength tests were performed to determine the toughness of the welds.

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Methodology for Process-independent Energetic Assessment of machine tools

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Procedia Manufacturing 2017年 8卷 254-261页

作者： Paetzold, Jörg Kolouch, Martin Wittstock, Volker Putz, Matthias Institute for Machine Tools and Production Processes Technische Universität Chemnitz Reichenhainer Straße 90 Chemnitz 09126 Germany Fraunhofer Institute for Machine Tools and Forming Technology Reichenhainer Straße 88 Chemnitz 09126 Germany

Energy-labels draw users’ attention to energy efficiency and thus they force the manufacturers to reduce the energy consumption of their products. This paper focuses on the large variety of metal-cutting machine tools, representing a challenge to find an evaluation basis for a unique energy-label. For this reason, the process-independent energy consumption has been compared to machine tool features and properties. The data-base contains measured values and has been extended by values from literature. Concerning a large number of various machining centers for milling operations, the statistical analysis shows the influence of the different machine tool features and properties on energy consumption. Finally, an evaluation basis is presented and the applicability on energy-labels is discussed. © 2017 The Authors

关键词： energy-efficiency energy-label machine tools statistical analysis

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On the correlation of hammer-peened surfaces and process, material and geometry parameters

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IOP Conference Series: Materials Science and Engineering 2019年第1期480卷

作者： S Pfeiffer M Fiedler T Bergelt M Kolouch M Putz M F-X Wagner Technische Universität Chemnitz Chair of Materials Science Chemnitz Germany Fraunhofer Institute for Machine Tools and Forming Technology IWU Chemnitz Germany

Hammer-peening can replace extensive hand-polishing during the processing of freeform surfaces, but it is rarely applied in practice due to the interplay of numerous parameters, including the process and tool parameters as well as the geometry and the material of the workpiece. In the present study we systematically investigate the effect of tool radii, tool angles, pressure, path and impact distance and the path definition (with respect to the direction of previous surface milling) on the resulting surface roughness and strain hardening of a cast iron, a low- and a high-alloyed steel using a pneumatic tool setup and complementary Finite Element (FE) simulations. Our experimental results show that an impact and path distance of 0.18 mm, a pressure of 7.3 bar and a tool radius of 8 mm reduce the surface roughness of a face-milled surface with an average roughness of Ra = 0.8 μm to an average roughness of Ra = 0.5 μm for all materials under consideration. The FE simulations indicate that, for a ball-milled surface, the surface roughness Ra decreases (and the arithmetical mean height Sa increases) the most for a tool angle of 45° and for a hammer-peening path perpendicular to the previous ball-milling path. These results contribute to the development of a mathematical model that allows to identify suitable parameter combinations prior to hammer-peening processing for a given workpiece surface.

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