TY - CHAP A1 - Röhrig, Christof A1 - Großmann, Uwe A1 - Künemund, Frank A1 - Gansemer, Sebastian A1 - Schürmann, Volker A1 - Wollert, Jörg T1 - Positionsbestimmung mittels Funktechnologien - Vergleich von Verfahren und Technologien mit exemplarischer Demonstration T2 - Wireless-Technologies-Kongress 2008 : von der Technologie zur Anwendung / Hrsg. Jörg F. Wollert Y1 - 2008 SN - 978-3-89838-608-1 SP - 337 EP - 348 PB - AKA CY - Heidelberg ER - TY - JOUR A1 - Raffeis, Iris A1 - Adjei-Kyeremeh, Frank A1 - Vroomen, Uwe A1 - Westhoff, Elmar A1 - Bremen, Sebastian A1 - Hohoi, Alexandru A1 - Bührig-Polaczek, Andreas T1 - Qualification of a Ni-Cu alloy for the laser powder bed fusion process (LPBF): Its microstructure and mechanical properties JF - Applied Sciences N2 - As researchers continue to seek the expansion of the material base for additive manufacturing, there is a need to focus attention on the Ni–Cu group of alloys which conventionally has wide industrial applications. In this work, the G-NiCu30Nb casting alloy, a variant of the Monel family of alloys with Nb and high Si content is, for the first time, processed via the laser powder bed fusion process (LPBF). Being novel to the LPBF processes, optimum LPBF parameters were determined, and hardness and tensile tests were performed in as-built conditions and after heat treatment at 1000 °C. Microstructures of the as-cast and the as-built condition were compared. Highly dense samples (99.8% density) were achieved after varying hatch distance (80 µm and 140 µm) with scanning speed (550 mm/s–1500 mm/s). There was no significant difference in microhardness between varied hatch distance print sets. Microhardness of the as-built condition (247 HV0.2) exceeded the as-cast microhardness (179 HV0.2.). Tensile specimens built in vertical (V) and horizontal (H) orientations revealed degrees of anisotropy and were superior to conventionally reported figures. Post heat treatment increased ductility from 20% to 31% (V), as well as from 16% to 25% (H), while ultimate tensile strength (UTS) and yield strength (YS) were considerably reduced. Y1 - 2020 U6 - http://dx.doi.org/10.3390/app10103401 SN - 2076-3417 N1 - Special Issue Materials Development by Additive Manufacturing Techniques VL - 10 IS - Art. 3401 SP - 1 EP - 15 PB - MDPI CY - Basel ER - TY - CHAP A1 - Nakagawa, Masaki A1 - Michaux, Frank A1 - Kallweit, Stephan A1 - Maeda, Kazuhiro T1 - Unsteady flow measurements in the wake behind a wind-tunnel car model by using high-speed planar PIV T2 - 11TH International Symposium on Particle Image Velocimetry – PIV15 Santa Barbara, California, September 14-16, 2015 N2 - This study investigates unsteady characteristics of the wake behind a 28%-scale car model in a wind tunnel using highspeed planar particle image velocimetry (PIV). The car model is based on a hatchback passenger car that is known to have relatively high fluctuations in its aerodynamic loads. This study primarily focuses on the lateral motion of the flow on the horizontal plane to determine the effect of the flow motion on the straight-line stability and the initial steering response of the actual car on a track. This paper first compares the flow fields in the wake behind the above mentioned model obtained using conventional and high-speed planar PIV, with sampling frequencies of 8 Hz and 1 kHz, respectively. Large asymmetrically coherent flow structures, which fluctuate at frequencies below 2 Hz, are observed in the results of highspeed PIV measurements, whereas conventional PIV is unable to capture these features of the flow owing to aliasing. This flow pattern with a laterally swaying motion is represented by opposite signs of cross-correlation coefficients of streamwise velocity fluctuations for the two sides of the car model. Effects of two aerodynamic devices that are known to reduce the fluctuation levels of the aerodynamic loads are then extensively investigated. The correlation analyses reveal that these devices indeed reduce the fluctuation levels of the flow and the correlation values around the rear combination-lamp, but it is found that the effects of these devices are different around the c-pillar. Y1 - 2015 ER - TY - CHAP A1 - Nakagawa, Masaki A1 - Kallweit, Stephan A1 - Michaux, Frank A1 - Hojo, Teppei T1 - Typical Velocity Fields and Vortical Structures around a Formula One Car, based on Experimental Investigations using Particle Image Velocimetry T2 - SAE International Journal of Passenger Cars - Mechanical Systems Y1 - 2016 U6 - http://dx.doi.org/10.4271/2016-01-1611 SN - 1946-4002 ER - TY - CHAP A1 - Kleine, Harald A1 - Kallweit, Stephan A1 - Michaux, Frank A1 - Havermann, Marc A1 - Olivier, Herbert T1 - PIV Measurement of Shock Wave Diffraction T2 - 18th International Symposium on Applications of Laser Techniques to Fluid Mechanics, 2016, Lissabon Y1 - 2016 SP - 1 EP - 14 ER - TY - JOUR A1 - Gebhardt, Andreas A1 - Schmidt, Frank-Michael A1 - Hötter, Jan-Steffen A1 - Sokalla, Wolfgang A1 - Sokalla, Patrick T1 - Additive Manufacturing by selective laser melting the realizer desktop machine and its application for the dental industry JF - Physics Procedia Y1 - 2010 SN - 1875-3892 N1 - Laser Assisted Net Shape Engineering 6, Proceedings of the LANE 2010, Part 2 VL - 5 IS - 2 SP - 543 EP - 549 ER - TY - JOUR A1 - Gebhardt, Andreas A1 - Schmidt, Frank-Michael T1 - Practical experiences with making and finishing of coloured models using 3D printing Y1 - 2002 N1 - International Conference on Rapid Prototyping and Manufacturing <2, 2002, Beijing> ER - TY - CHAP A1 - Gebhardt, Andreas A1 - Schmidt, Frank-Michael T1 - Farbige Prototypen als Werkzeug für den Konstrukteur T1 - Colored prototypes as instrument for the constructing engineer N2 - Physische Prototypen, also Anschauungs- und Funktionsmodelle nach den generativen oder Rapid Prototyping (RP) Verfahren haben sich in diesem Zusammenhang vor allem als Hilfsmittel zur effektiven Kommunikation und zur Evaluierung von Produkteigenschaften einen festen Platz in der Produktentstehung erworben. Die positiven Effekte der etablierten RP Verfahren sind unumstritten. Einfachere, schnellere und wirtschaftlichere Maschinen (Prototyper, Fabrikator), vor allem auch für die Büroumgebung, geben neue Impulse im Sinne der Optimierung der heutigen Verfahren. Eine neue Dimension verspricht die Option „Farbe“ der bisher fast ausschließlich monochromen Modelle. Ist Farbe nur „nice to have“ oder welchen Effekt haben farbige Modelle als Werkzeug von Konstrukteuren und Produktenwicklern? Welche Perspektiven bietet „Farbe“ darüber hinaus? KW - Prototyping KW - Rapid prototyping KW - Prototypen KW - Funktionsmodelle KW - Produktentstehung KW - Prototyper KW - Produktenwicklung KW - prototypes KW - working models KW - product emergence KW - prototyper KW - product development Y1 - 2005 ER - TY - JOUR A1 - Gebhardt, Andreas A1 - Brücker, Christoph A1 - Schmidt, Frank-Michael T1 - RP gestützte Herstellung komplexer transparenter Hohlräume für die Strömungsanalyse N2 - Die Berechnung der Durchströmung von Bauteilen ist gegenüber derjenigen von umströmten Bauteilen deutlich im Hintertreffen. Das liegt vor allem an der fehlenden Verfügbarkeit geeigneter optisch transparenter Modellkanäle für die experimentelle Analyse. Der Beitrag stellt ein Verfahren zur Herstellung transparenter durchströmter Geometrien auf der Basis generativ gefertigter Urmodelle vor. Damit können beliebig komplexe Innenströmungen optisch analysiert werden. Anhand von zwei Beispielen aus der Medizin, der Modellierung der oberen Atemwege und des Bronchialbaums, wird das Verfahren vorgeführt. Der generative Bauprozess mittels 3D-Printing wird beschrieben und die Abformung in transparentem Silikon gezeigt. Schließlich werden beispielhaft der Messaufbau und Ergebnisse der Anwendung vorgestellt. Das Verfahren bildet die Grundlage für die Analyse und Berechnung komplexer Innenströmungen und trägt somit zur Verbesserung zahlreicher technischer Anwendungen bei. N2 - Unlike the flow around technical products the interior flow is not understood very well. That’s mainly because of a lack of suitable transparent investigation tunnels that are needed to apply optical methods. The paper proposes a procedure to make precise complex hollow structures from a highly transparent material using masters from generative or Rapid Prototyping processes. Taking two examples from the medical field, the upper human airways and the bronchial tree, the entire process is shown. The 3D Printing build process is illustrated as well as the silicon casting process. Finally the measuring equipment is demonstrated and sample results are given. The process establishes the basis for the investigation and calculation of complex interior flow pattern and therefore contributes to a better understanding and consequently improvement of appropriate technical products. KW - Rapid prototyping KW - Rapid Prototyping KW - Strömungsanalyse KW - Innenströmung KW - Modellkanäle KW - 3D-Printing Y1 - 2005 ER - TY - BOOK A1 - Engeln-Müllges, Gisela A1 - Uhlig, Frank T1 - Numeric Algorithms with Fortran Y1 - 1996 SN - 3-540-60529-0 PB - Springer CY - Berlin [u.a.] ER - TY - BOOK A1 - Engeln-Müllges, Gisela A1 - Uhlig, Frank T1 - Numerical algorithms with C Y1 - 1996 SN - 3-540-60530-0 PB - Springer CY - Berlin [u.a.] ER - TY - CHAP A1 - Dilger, Klaus A1 - Mund, Frank A1 - Dilthey, Ulrich A1 - Schleser, Markus A1 - Raupach, Michael A1 - Walk-Lauffer, Bernd ED - Curbach, Manfred T1 - Einsatz einer polymeren Phase zur Verbundverbesserung T2 - Textile reinforced structures : proceedings of the 2nd Colloquium on Textile Reinforced Structures (CTRS2), Dresden, Germany, 29.9. - 1.10.2003 Y1 - 2003 SN - 3-86005-386-8 SP - 133 EP - 144 PB - Techn. Univ. CY - Dresden ER -