@article{KallweitSchimpf2003, author = {Kallweit, Stephan and Schimpf, Axel}, title = {Photogrammetric Particle Image Velocimetry / Schimpf, Axel ; Kallweit, Stephan}, series = {Particle image velocimetry : recent improvements; proceedings of the Europiv 2 Workshop held in Zaragoza, Spain, March 31 - April 1, 2003 / edited by M. Stanislas ...}, journal = {Particle image velocimetry : recent improvements; proceedings of the Europiv 2 Workshop held in Zaragoza, Spain, March 31 - April 1, 2003 / edited by M. Stanislas ...}, publisher = {Springer}, address = {Berlin}, isbn = {3-540-21423-2}, pages = {295}, year = {2003}, language = {en} } @article{KallweitWillertDuesetal.2008, author = {Kallweit, Stephan and Willert, Chris and Dues, Michael and M{\"u}ller, Ulrich}, title = {PIV for Volume Flow Metering / Kallweit, Stephan ; Willert, Chris ; Dues, Michael ; M{\"u}ller, Ulrich ; Lederer, Thomas}, pages = {6 S.}, year = {2008}, language = {en} } @article{KallweitKaminskyRossietal.2008, author = {Kallweit, Stephan and Kaminsky, Radoslav and Rossi, Massimiliano and Morbiducci, Umberto}, title = {PIV Measurements of Flows in Artificial Heart Valves / Kaminsky, Radoslav ; Kallweit, Stephan ; Rossi, Massimiliano ; Morbiducci, Umberto ; Scalise, Lorenzo}, series = {Particle Image Velocimetry - New Developments and Recent Applications}, journal = {Particle Image Velocimetry - New Developments and Recent Applications}, isbn = {978-3-540-73528-1}, pages = {55 -- 72}, year = {2008}, language = {en} } @article{KallweitKaminskyRossietal.2005, author = {Kallweit, Stephan and Kaminsky, R. and Rossi, M. and Scalise, L.}, title = {PIV Measurements with high temporal Resolution behind Artificial Heart Valves / Kaminsky, R. ; Rossi, M. ; Scalise, L. ; Kallweit, S. ; Verdonck, P.}, series = {Proceedings of the 6th International Symposium on Particle Image Velocimetry}, journal = {Proceedings of the 6th International Symposium on Particle Image Velocimetry}, publisher = {Caltech}, address = {Pasadena, CA}, year = {2005}, language = {en} } @article{GebhardtSchmidt2002, author = {Gebhardt, Andreas and Schmidt, Frank-Michael}, title = {Practical experiences with making and finishing of coloured models using 3D printing}, year = {2002}, language = {en} } @article{AnikFrohbergKapoor1983, author = {Anik, Sabri and Frohberg, Martin G. and Kapoor, Madan Lal}, title = {Prediction of thermodynamic properties of oxygen in binary metallic solvents}, series = {Zeitschrift f{\"u}r Metallkunde}, volume = {74}, journal = {Zeitschrift f{\"u}r Metallkunde}, number = {6}, issn = {0044-3093}, pages = {372 -- 375}, year = {1983}, language = {en} } @article{FateriGebhardt2015, author = {Fateri, Miranda and Gebhardt, Andreas}, title = {Process Parameters Development of Selective Laser Melting of Lunar Regolith for On-Site Manufacturing Applications}, series = {International Journal of Applied Ceramic Technology}, volume = {12}, journal = {International Journal of Applied Ceramic Technology}, number = {1}, publisher = {Wiley-Blackwell}, address = {Oxford}, isbn = {1744-7402}, doi = {10.1111/ijac.12326}, pages = {46 -- 52}, year = {2015}, language = {en} } @article{RaffeisAdjeiKyeremehVroomenetal.2020, author = {Raffeis, Iris and Adjei-Kyeremeh, Frank and Vroomen, Uwe and Westhoff, Elmar and Bremen, Sebastian and Hohoi, Alexandru and B{\"u}hrig-Polaczek, Andreas}, title = {Qualification of a Ni-Cu alloy for the laser powder bed fusion process (LPBF): Its microstructure and mechanical properties}, series = {Applied Sciences}, volume = {10}, journal = {Applied Sciences}, number = {Art. 3401}, publisher = {MDPI}, address = {Basel}, issn = {2076-3417}, doi = {10.3390/app10103401}, pages = {1 -- 15}, year = {2020}, abstract = {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.}, language = {en} } @article{KunkelGebhardtMpofuetal.2019, author = {Kunkel, Maximilian Hugo and Gebhardt, Andreas and Mpofu, Khumbulani and Kallweit, Stephan}, title = {Quality assurance in metal powder bed fusion via deep-learning-based image classification}, series = {Rapid Prototyping Journal}, volume = {26}, journal = {Rapid Prototyping Journal}, number = {2}, issn = {1355-2546}, doi = {10.1108/RPJ-03-2019-0066}, pages = {259 -- 266}, year = {2019}, language = {en} } @article{FranzenPindersPfaffetal.2018, author = {Franzen, Julius and Pinders, Erik and Pfaff, Raphael and Enning, Manfred}, title = {RailCrowd's virtual fleets: Make most of your asset data}, series = {Deine Bahn}, journal = {Deine Bahn}, number = {9}, publisher = {Bahn-Fachverlag}, address = {Berlin}, issn = {0948-7263}, pages = {11 -- 13}, year = {2018}, abstract = {For smaller railway operators or those with a diverse fleet, it can be difficult to collect sufficient data to improve maintenance programs. At the same time, new rules such as entity in charge of maintenance - ECM - regulations impose an additional workload by requiring a dedicated maintenance management system and specific reports. The RailCrowd platform sets out to facilitate compliance with ECM and similar regulations while at the same time pooling anonymised fleet data across operators to form virtual fleets, providing greater data insights.}, language = {en} } @article{Gebhardt2004, author = {Gebhardt, Andreas}, title = {Rapid Prototyping}, series = {Landolt-B{\"o}rnstein - Group VIII Advanced Materials and Technologies‡Vol. 1 Laser Physics and Applications‡Subvol. C Laser Applications / authors: B{\"a}uerle, D. ...}, journal = {Landolt-B{\"o}rnstein - Group VIII Advanced Materials and Technologies‡Vol. 1 Laser Physics and Applications‡Subvol. C Laser Applications / authors: B{\"a}uerle, D. ...}, publisher = {Heidelberg}, address = {Springer}, isbn = {3-540-00105-0}, pages = {105 -- 123}, year = {2004}, language = {en} } @article{Gebhardt2001, author = {Gebhardt, Andreas}, title = {Rapid Prototyping and PIV}, year = {2001}, language = {en} } @article{LeidingerNoistenWollert2012, author = {Leidinger, Rafael and Noisten, Thomas and Wollert, J{\"o}rg}, title = {Realtime automation networks in moVing industrial environments}, series = {Journal of systemics, cybernetics and informatics}, volume = {Vol. 10}, journal = {Journal of systemics, cybernetics and informatics}, number = {Iss. 2}, publisher = {IIIC}, address = {Orlando}, issn = {1690-4532}, pages = {52 -- 56}, year = {2012}, abstract = {The radio-based wireless data communication has made the realization of new technical solutions possible in many fields of the automation technology (AT). For about ten years, a constant disproportionate growth of wireless technologies can be observed in the automation technology. However, it shows that especially for the AT, conventional technologies of office automation are unsuitable and/or not manageable. The employment of mobile services in the industrial automation technology has the potential of significant cost and time savings. This leads to an increased productivity in various fields of the AT, for example in the factory and process automation or in production logistics. In this paper technologies and solutions for an automation-suited supply of mobile wireless services will be introduced under the criteria of real time suitability, IT-security and service orientation. Emphasis will be put on the investigation and development of wireless convergence layers for different radio technologies, on the central provision of support services for an easy-to-use, central, backup enabled management of combined wired / wireless networks and on the study on integrability in a Profinet real-time Ethernet network.}, language = {en} } @article{KaemperPappasHopster1990, author = {K{\"a}mper, Klaus-Peter and Pappas, D. P. and Hopster, H.}, title = {Reversible transition between perpendicular and in-plane magnetization in ultrathin films. Pappas, D. P.; K{\"a}mper, K.-P.; Hopster, H.}, series = {Physical Review Letters. 64 (1990), H. 26}, journal = {Physical Review Letters. 64 (1990), H. 26}, isbn = {1079-7114}, pages = {3179 -- 3182}, year = {1990}, language = {en} } @article{MichauxMatternKallweit2018, author = {Michaux, F. and Mattern, P. and Kallweit, Stephan}, title = {RoboPIV: how robotics enable PIV on a large industrial scale}, series = {Measurement Science and Technology}, volume = {29}, journal = {Measurement Science and Technology}, number = {7}, publisher = {IOP}, address = {Bristol}, issn = {1361-6501}, doi = {10.1088/1361-6501/aab5c1}, pages = {074009}, year = {2018}, abstract = {This work demonstrates how the interaction between particle image velocimetry (PIV) and robotics can massively increase measurement efficiency. The interdisciplinary approach is shown using the complex example of an automated, large scale, industrial environment: a typical automotive wind tunnel application. Both the high degree of flexibility in choosing the measurement region and the complete automation of stereo PIV measurements are presented. The setup consists of a combination of three robots, individually used as a 6D traversing unit for the laser illumination system as well as for each of the two cameras. Synchronised movements in the same reference frame are realised through a master-slave setup with a single interface to the user. By integrating the interface into the standard wind tunnel management system, a single measurement plane or a predefined sequence of several planes can be requested through a single trigger event, providing the resulting vector fields within minutes. In this paper, a brief overview on the demands of large scale industrial PIV and the existing solutions is given. Afterwards, the concept of RoboPIV is introduced as a new approach. In a first step, the usability of a selection of commercially available robot arms is analysed. The challenges of pose uncertainty and importance of absolute accuracy are demonstrated through comparative measurements, explaining the individual pros and cons of the analysed systems. Subsequently, the advantage of integrating RoboPIV directly into the existing wind tunnel management system is shown on basis of a typical measurement sequence. In a final step, a practical measurement procedure, including post-processing, is given by using real data and results. Ultimately, the benefits of high automation are demonstrated, leading to a drastic reduction in necessary measurement time compared to non-automated systems, thus massively increasing the efficiency of PIV measurements.}, language = {en} } @article{HoetterFateriGebhardt2012, author = {H{\"o}tter, Jan-Steffen and Fateri, Miranda and Gebhardt, Andreas}, title = {Selective laser melting of metals: desktop machines open up new chances even for small companies}, series = {Advanced materials research}, volume = {622-623}, journal = {Advanced materials research}, publisher = {Trans Tech Publ.}, address = {Baech}, issn = {1662-8985 (E-Journal); 1022-6680 (Print)}, doi = {10.4028/www.scientific.net/AMR.622-623.461}, pages = {461 -- 465}, year = {2012}, abstract = {Additive manufacturing (AM) of metal parts by using Selective Laser Melting (SLM) has become a powerful tool mostly in the area of automotive, aerospace engineering and others. Especially in the field of dentistry, jewelry and related branches that require individualized or even one-of-a-kind products, the direct digital manufacturing process opens up new ways of design and manufacturing. In these fields, mostly small and medium sized businesses (SME) are operating which do not have sufficient human and economic resources to invest in this technology. But to stay competitive, the application of AM can be regarded as a necessity. In this situation a new desktop machine (Realizer SLM 50) was introduced that cost about 1/3 of a shop floor SLM machine and promises small quality parts. To find out whether the machine really is an alternative for SMEs the University of Applied Science, Aachen, Germany, designed, build and optimized typical parts from the dentistry and the jewelry branches using CoCr and silver material, the latter being new with this application. The paper describes the SLM procedure and how to find and optimize the most important parameters. The test is accompanied by digital simulation in order to verify the build parameters and to plan future builds. The procedure is shown as well as the resulting parts made from CoCr and silver material.}, language = {en} } @article{FateriGebhardt2015, author = {Fateri, Miranda and Gebhardt, Andreas}, title = {Selective Laser Melting of Soda-Lime Glass Powder}, series = {International Journal of Applied Ceramic Technology}, volume = {12}, journal = {International Journal of Applied Ceramic Technology}, number = {1}, publisher = {Wiley-Blackwell}, address = {Oxford}, issn = {1744-7402}, doi = {10.1111/ijac.12338}, pages = {53 -- 61}, year = {2015}, language = {en} } @article{RieperGebhardtStucker2016, author = {Rieper, Harald and Gebhardt, Andreas and Stucker, Brent}, title = {Selective Laser Melting of the Eutectic Silver-Copper Alloy Ag 28 wt \% Cu}, series = {RTejournal - Forum f{\"u}r Rapid Technologie}, volume = {13}, journal = {RTejournal - Forum f{\"u}r Rapid Technologie}, issn = {1614-0923}, url = {http://nbn-resolving.de/nbn:de:0009-2-44141}, year = {2016}, abstract = {The aim of this work was to perform a detailed investigation of the use of Selective Laser Melting (SLM) technology to process eutectic silver-copper alloy Ag 28 wt. \% Cu (also called AgCu28). The processing occurred with a Realizer SLM 50 desktop machine. The powder analysis (SEM-topography, EDX, particle distribution) was reported as well as the absorption rates for the near-infrared (NIR) spectrum. Microscope imaging showed the surface topography of the manufactured parts. Furthermore, microsections were conducted for the analysis of porosity. The Design of Experiments approach used the response surface method in order to model the statistical relationship between laser power, spot distance and pulse time.}, language = {en} } @article{KaemperBergBegemannetal.1998, author = {K{\"a}mper, Klaus-Peter and Berg, U. and Begemann, M. and Hagemann, B. (u.a.)}, title = {Series production and testing of a micro motor. Serienfertigung und Pr{\"u}fung eines Mikromotors}, series = {Actuator 98 : 6th International Conference on New Actuators ; 17 - 19 June, 1998, Bremen, Germany ; conference proceedings / ed.: Hubert Borgmann ...}, journal = {Actuator 98 : 6th International Conference on New Actuators ; 17 - 19 June, 1998, Bremen, Germany ; conference proceedings / ed.: Hubert Borgmann ...}, publisher = {Messe Bremen}, address = {Bremen}, isbn = {3-933339-00-6}, pages = {552 -- 555}, year = {1998}, language = {en} } @article{ReisgenSchleserMokrovetal.2010, author = {Reisgen, Uwe and Schleser, Markus and Mokrov, Oleg and Ahmed, Essam}, title = {Shielding gas influences on laser weldability of tailored blanks of advanced automotive steels}, series = {Applied surface science}, volume = {257}, journal = {Applied surface science}, number = {5}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0169-4332 (E-Journal); 0169-4332 (Print)}, doi = {10.1016/j.apsusc.2010.08.042}, pages = {1401 -- 1406}, year = {2010}, abstract = {The effects of shielding gas types and flow rates on CO2 laser weldability of DP600/TRIP700 steel sheets were studied in this work. The evaluated shielding gases were helium (He), argon (Ar) and different mixtures of He and Ar. Weld penetration, tensile strength and formability (Erichsen test) of laser welds were found to be strongly dependent upon the shielding gas types. The ability of shielding gas in removing plasma plume and thus increasing weld penetration is believed to be closely related to ionization potential and atomic weight which determine the period of plasma formation and disappearance. It was found that the higher helium shielding gas flow rate, the deeper weld penetration and the lower weld width.}, language = {en} }