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Suche nach „[Nachhaltig]“ hat 1316 Publikationen gefunden
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    DigitalNachhaltigF: Maschinenbau und MechatronikI: Fraunhofer AWZ CTMT

    Zeitschriftenartikel

    A. Stock, Gabriel Herl, T. Sauer, Jochen Hiller

    Edge-preserving compression of CT scans using wavelets

    Insight - Non-Destructive Testing and Condition Monitoring (The British Institute of Non-Destructive Testing), vol. 62, no. 6, pp. 345-351

    2020

    DOI: 10.1784/insi.2020.62.6.345

    Abstract anzeigen

    This work addresses the subject of efficient storage of computed tomography (CT) data with an emphasis on the quality of surfaces. Industrial dimensional metrology often requires high measurement accuracy and it is shown that this is retained using wavelet-based compression methods. The applied techniques include a tensor product wavelet transform and soft wavelet shrinkage. In these tests, performed on real objects, dimensional CT measurements of compressed and uncompressed volumes were compared. The necessary storage space was reduced significantly with a negligible loss of accuracy. The storage space required for a multi-sphere phantom was decreased to 4.7% (from 638 MB to 30 MB), with an average deviation below 1 μm from the original volume.

    DigitalNachhaltigExtern

    Vortrag

    T. Heberholz, Andrey Prihodovsky, M. Nowottnick

    Einfluss eines abnormalen (CuNi)6Sn5/(NiCu)3Sn4-Schichtwachstums auf die Robustheit von bleifreien Zinn-Silber-Basis-Lotstellen bei Temperaturen oberhalb von 175 °C

    Fachtagung/Konferenz EBL 2020 - Elektronische Baugruppen und Leiterplatten, Fellbach

    2020

    DigitalNachhaltigExtern

    Zeitschriftenartikel

    Anton Schmailzl, Johannes Käsbauer, J. Martan, P. Honnerová, F. Schäfer, Maximilian Fichtl, T. Lehrer, L. Prušáková, J. Tesař, J. Skála, M. Honner

    Measurement of core temperature through semi-transparent polyamide 6 using scanner-integrated pyrometer in laser welding

    International Journal of Heat and Mass Transfer, vol. 146, no. January

    2020

    DOI: 10.1016/j.ijheatmasstransfer.2019.118814

    Abstract anzeigen

    Predicting the core temperature during welding is an ambitious aim in many research works. In this work, a 3D-scanner with integrated pyrometer is characterized and used to measure the temperature during quasi-simultaneous laser transmission welding of polyamide 6. However, due to welding in an overlap configuration, the heat radiation emitted from the joining zone of a laser transmission weld has to pass through the upper polymer, which is itself a semi-transparent emitter. Therefore, the spectral filtering of the heat radiation in the upper polymer is taken into account by calibrating the pyrometer for the measurement task. Thermal process simulations are performed to compare the temperature field with the measured temperature signal. The absorption coefficients of the polymers are measured, in order to get precise results from the computation. The temperature signals during welding are in good agreement with the computed mean temperature inside the detection spot, located in the joining area. This is also true for varying laser power, laser beam diameter and the carbon black content in the lower polymer. Both, the computed mean temperature and the temperature signal are representing the core temperature. In order to evaluate the spatial sensitivity of the measurement system, the emitted heat radiation from both polymers is calculated on basis of the computed temperature field. Hereby it is found, that more than 90 percent of the detected heat radiation comes from the joining area, which is a crucial information for contact-free temperature measurement tasks on semi-transparent polymers.

    DigitalNachhaltigExtern

    Vortrag

    Johannes Käsbauer, Anton Schmailzl, T. Loose, S. Hierl

    Potentials of the EFG-Method for Modeling Quasi-Simultaneous Laser Transmission Welding Considering the Melt Flow

    Simulationsforum 2019 Schweißen und Wärmebehandlung, Weimar

    2020

    DigitalNachhaltigExtern

    Vortrag

    Johannes Käsbauer, Anton Schmailzl, T. Loose, S. Hierl

    Thermo-Mechanical Modeling of Quasi-Simultaneous Laser Transmission Welding using LS-DYNA with Focus on Accuracy of Heat Input Calculation

    Technology Day 2020 - Plastics on the test rig, Traboch, Österreich

    2020

    DigitalNachhaltigExtern

    Zeitschriftenartikel

    Johannes Käsbauer, Anton Schmailzl, J. Prehm, T. Loose, S. Hierl

    Simulation of Quasi-Simultaneous Laser Transmission Welding of Plastics: Optimization of Material Parameters in Broad Temperature Range

    Procedia CIRP, vol. 94, pp. 737-741

    2020

    DOI: 10.1016/j.procir.2020.09.136

    Abstract anzeigen

    Thermo-mechanical simulation offers great opportunities to optimize welding processes of plastics. For realistic simulation, the temperature dependent mechanical properties need to be implemented from ambient temperature to temperatures above the flow temperature. Standard test methods are insufficient for characterization in the entire temperature range because close to the flow temperature the material is too soft for tensile tests and too stiff for rheometry. Therefore, an optimization strategy is developed, that determines unknown material parameters by testing in welding simulations. The unknown parameters are iteratively adjusted to minimize the mismatch between computed and measured set-paths. Thus, important process characteristics are calculated realistically, enabling the computer aided assessment of the weld quality.

    NachhaltigF: Angewandte Naturwissenschaften und WirtschaftsingenieurwesenS: IPH Teisnach

    Beitrag (Sammelband oder Tagungsband)

    Sebastian Sitzberger, Johannes Liebl, Christian J. Trum, Rolf Rascher

    Concept of a two-part clamping system for lenses in optical metrology

    Proceedings of SPIE 11478 (Seventh European Seminar on Precision Optics Manufacturing [8 July 2020; Teisnach]), Bellingham, WA, USA

    2020

    DOI: 10.1117/12.2566547

    Abstract anzeigen

    The developed concept represents a universally applicable clamping system designed to fit in any measuring machine with any measuring principle. The design ensures that, as long as the lens remains clamped, the measurement results are reproducible. Form errors due to tension remain constant across all measuring and processing steps. The version presented in this paper was developed especially for small lenses in the diameter range up to 40 mm. On the one hand, the design allows for fast measurement of loose lenses. On the other hand, the device can also be used for measurement comparisons, since lenses can also be mounted permanently. In the following, the concept and first results of measurement tests are presented.

    NachhaltigF: Angewandte Naturwissenschaften und WirtschaftsingenieurwesenS: IPH Teisnach

    Beitrag (Sammelband oder Tagungsband)

    Armin Reif, Sebastian Sitzberger, Rolf Rascher

    Cutting high-performance materials with ultrasonically modulated cutting speed

    Proceedings of SPIE 11478 (Seventh European Seminar on Precision Optics Manufacturing [8 July 2020; Teisnach]), Bellingham, WA, USA

    2020

    DOI: 10.1117/12.2565757

    Abstract anzeigen

    The continuing trend towards lightweight construction and the associated machining rates of up to 95 % lead to an increased use of high-performance materials. The ever growing demands on the strength and quality of components and the associated use of materials which are hard to machine require the further development of new, economical machining techniques. In ultrasonic-assisted machining, an additional high-frequency vibration is superimposed on the conventional machining process. The vibration of the tool is usually excited axially or longitudinally to the workpiece, i.e. vertical to the cutting direction. An additional vibration overlay around the rotation axis (torsional) of the tool is also possible. This generates a vibration overlay in the cutting direction. The vibration initiation causes vibration amplitudes in the range of a few micrometers at the tool cutting edge. This leads in turn to a high-frequency change in the cutting speed or feed rate. Overall, an additional torsional vibration overlap can further reduce cutting forces, increase tool life and improve workpiece quality. In order for a grinding tool to generate a torsional vibration, a special tool was required that had to be designed by simulation. The formation of a torsional vibration was achieved by helical slots in the sonotrode. Depending on the angle of rotation and the length of the slots, a part of the axial vibration is converted into a torsional vibration by an axial excitation of the sonotrode. The aim in designing the slots was to achieve the highest possible vibration amplitude. Following the simulation, the slots were inserted into the tool in the corresponding optimum geometric position. Afterwards, the specially designed grinding tool was validated by machining the brittle-hard glass-ceramic material Zerodur. The first test results with the torsionally vibrating tool are presented in the following.

    NachhaltigF: Angewandte Naturwissenschaften und WirtschaftsingenieurwesenS: IPH Teisnach

    Zeitschriftenartikel

    Armin Reif, P. Rinck, Sebastian Sitzberger, Rolf Rascher, M. Zäh

    Zerspanung von Hochleistungswerkstoffen mit ultrasonisch modulierter Schnittgeschwindigkeit

    ZWF - Zeitschrift für wirtschaftlichen Fabrikbetrieb, vol. 115, no. 3, pp. 2-5

    2020

    DOI: 10.3139/104.112255

    Abstract anzeigen

    Die steigenden Anforderungen an die Festigkeit und die Qualität von Bauteilen und die damit verbundene Verwendung hochfester Materialien erfordert die Weiterentwicklung neuer wirtschaftlicher Zerspanungstechniken. Durch eine werkzeugseitige Schwingungsüberlagerung können bei der Bearbeitung von schwer zerspanbaren Werkstoffen die Zerspankräfte und der Werkzeugverschleiß reduziert sowie die Oberflächenqualität verbessert werden.

    NachhaltigF: Elektrotechnik und MedientechnikI: IQMA

    Zeitschriftenartikel

    H. Fan, Y. Zhang, D. Liu, C. Niu, L. Liu, W. Ni, Y. Xia, Z. Bi, Günther Benstetter, G. Lei

    Tensile stress-driven cracking of W fuzz over W crystal under fusion-relevant He ion irradiations

    Nuclear Fusion, vol. 60, no. 4

    2020

    DOI: 10.1088/1741-4326/ab71bb

    Abstract anzeigen

    Although W fuzz is formed in the divertor region of the fusion reactor, no theory may clearly explain the W fuzz growth mechanism. In this study, we observe the growth process of W fuzz over W crystal under ITER-relevant He ion irradiations. We propose the tensile stress-driven cracking of nano-structured fuzz during the initial growth of W fuzz. We demonstrate that the existence of tensile stress is due to the swelling of He nano-bubbles in the fuzz. After this cracking, the W fuzz breaks away from the planar network and grows over the W surface, where the micro-stress in the W surface layer acts as the driving force.

    NachhaltigS: TC Teisnach Sensorik

    Patent

    R. Berger, W. Lehnert, G. Metzger-Brueckl, Günther Ruhl, R. Rupp

    Wafer composite and method for producing semiconductor components

    2020

    NachhaltigS: TC Teisnach Sensorik

    Patent

    R. Rupp, Günther Ruhl, H.-J. Schulze

    Silicon carbide semiconductor device and a method for forming a silicon carbide semiconductor device

    2020

    NachhaltigF: Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Vortrag

    David Scholz, Thomas Stirner

    Hartree-Fock simulation of hematite surfaces with a posteriori calculation of correlation energy

    Preisträgervortrag zur Verleihung des Georg-Simon-Ohm-Preises der Deutschen Physikalischen Gesellschaft an David Scholz

    DPG-Frühjahrstagung, Dresden (abgesagt wegen Covid-19, gehalten an THD), Dresden

    2020

    NachhaltigF: Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Zeitschriftenartikel

    Thomas Stirner, David Scholz, J. Sun

    Convergence of surface energy calculations for various methods: (001), (012), (100) hematite and the applicability of the standard approach

    Journal of Physics: Condensed Matter, vol. 32, no. 18

    2020

    DOI: 10.1088/1361-648X/ab6f88

    Abstract anzeigen

    Three different methods for the calculation of the surface energy, namely the standard approach, the Boettger relation and the linear-fit method, are applied to the (0 0 1), (0 1 2) and (1 0 0) hematite surfaces. The standard approach was previously shown to suffer from a divergence problem, and the Boettger relation was shown to exhibit quantum size effects. While the linear-fit method, in general, leads to a good convergence behavior of the surface energy, the questions arise whether the relative order of the calculated surface energies depends on the chosen calculation method, and whether there is any merit at all in employing the standard approach. The present work investigates these questions with hematite as a benchmark material system. The simulations show that, for the surface facets and slab thicknesses studied here, the relative order of the surface energies is unaffected by the chosen calculation method. A regime is found where the three methods are in reasonably good agreement with respect to the obtained surface energies. Finally, a procedure is put forward to extract meaningful surface energy values from the standard approach.

    MobilNachhaltigF: Angewandte InformatikS: TC Plattling MoMo

    Beitrag (Sammelband oder Tagungsband)

    Markus Eider, Andreas Berl

    Requirements for prescriptive recommender systems extending the lifetime of EV batteries

    Proceedings of the 2020 10th International Conference on Advanced Computer Information Technologies (ACIT) [September 6-8, 2020; Deggendorf]

    2020

    DOI: 10.1109/ACIT49673.2020.9209011

    Abstract anzeigen

    Lithium-ion batteries in electric vehicles are subject to degradation, which is strongly influenced by the actions of vehicle users. Hereby, inexperienced users can cause the battery to reach its end of life state earlier than average. For this reason, this paper proposes the concept of a prescriptive recommender system that supports users in planning their utilization actions. The paper identifies functionalities of decision support systems relevant to extend the lifetime of electric and electronic systems. This allows to determe generic functional and non-functional requirements for prescriptive recommender systems. Further, the derived requirements are discussed in connection to the practicability of a prescriptive recommender system.

    DigitalNachhaltigF: Angewandte InformatikS: TC Freyung

    Vortrag

    Melanie Piser, Sebastian Wöllmann

    Digitale Partizipation als Prozessbeschleuniger für öffentliche Projekte - Bürgerbeteiligung im Projekt ALIA in der Gemeinde Weiherhammer

    Posterpräsentation

    INUAS International Conference 2020: Ressourcen - Zeit, Raum, Energie, Material (INUAS-Konferenzreihe - Urbane Transformationen: Wohnen, Ressourcen, Öffentliche Räume), München

    2020

    DigitalNachhaltigF: Angewandte InformatikS: TC Freyung

    Vortrag

    Melanie Piser, Sebastian Wöllmann

    Digitale Partizipation von FörderschülerInnen zur sozial und materiell nachhaltigen Gestaltung des Baubestands - Chancen digitaler Beteiligung von SchülerInnen am Beispiel der Schulhaussanierung des Rupert-Egenberger-Förderschulzentrums in der Stadt Amberg/Opf.

    Posterpräsentation

    INUAS International Conference 2020: Ressourcen - Zeit, Raum, Energie, Material (INUAS-Konferenzreihe - Urbane Transformationen: Wohnen, Ressourcen, Öffentliche Räume), München

    2020

    DigitalNachhaltigF: Angewandte InformatikS: TC Freyung

    Vortrag

    Melanie Piser, Sebastian Wöllmann

    Digitale Partizipation als Prozessbeschleuniger für öffentliche Projekte - Bürgerbeteiligung im Projekt ALIA in der Gemeinde Weiherhammer

    INUAS International Conference 2020: Ressourcen - Zeit, Raum, Energie, Material (INUAS-Konferenzreihe - Urbane Transformationen: Wohnen, Ressourcen, Öffentliche Räume), München

    2020

    DigitalNachhaltigF: Angewandte InformatikS: TC Freyung

    Vortrag

    Melanie Piser, Sebastian Wöllmann

    Digitale Partizipation von FörderschülerInnen zur sozial und materiell nachhaltigen Gestaltung des Baubestands - Chancen digitaler Beteiligung von SchülerInnen am Beispiel der Schulhaussanierung des Rupert-Egenberger-Förderschulzentrums in der Stadt Amberg/Opf.

    INUAS International Conference 2020: Ressourcen - Zeit, Raum, Energie, Material (INUAS-Konferenzreihe - Urbane Transformationen: Wohnen, Ressourcen, Öffentliche Räume), München

    2020

    DigitalNachhaltigF: Angewandte InformatikS: TC Freyung

    Vortrag

    Melanie Piser, Sebastian Wöllmann, Roland Zink

    Adolescents in Spatial Planning - A Digital Participation Platform for Smart Environmental and Democratic Education in Schools

    Video presentation

    21st Annual International Digital Landscape Architecture Conference 2020 (DLA), All-virtual online event (on-site conference at Harvard GSD, Boston, MA, USA cancelled)

    2020