TY - CHAP A1 - Pfaff, Raphael A1 - Pichler, Alexander A1 - George, Alfred A1 - Seiler, Friedrich T1 - Model based image processing for flow visualisation : 16th International Conference on Systems Science, Wroclaw, Poland, September 04 - 06, 2007 T2 - PU / Institut Franco-Allemand de Recherches de Saint-Louis ; 2007, 620 Y1 - 2007 SP - 1 EP - 10 PB - ISL CY - Saint Louis, France ER - TY - JOUR A1 - Fateri, Miranda A1 - Gebhardt, Andreas T1 - Selective Laser Melting of Soda-Lime Glass Powder JF - International Journal of Applied Ceramic Technology Y1 - 2015 U6 - https://doi.org/10.1111/ijac.12338 SN - 1744-7402 VL - 12 IS - 1 SP - 53 EP - 61 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Fateri, Miranda A1 - Gebhardt, Andreas T1 - Process Parameters Development of Selective Laser Melting of Lunar Regolith for On-Site Manufacturing Applications JF - International Journal of Applied Ceramic Technology Y1 - 2015 SN - 1744-7402 U6 - https://doi.org/10.1111/ijac.12326 VL - 12 IS - 1 SP - 46 EP - 52 PB - Wiley-Blackwell CY - Oxford ER - TY - CHAP A1 - Fateri, Miranda A1 - Gebhardt, Andreas T1 - Jewelry fabrication via selective laser melting of glass T2 - ASME 2014 12th Biennial Conference on Engineering Systems Design and Analysis Volume 1: Applied Mechanics; Automotive Systems; Biomedical Biotechnology Engineering; Computational Mechanics; Design; Digital Manufacturing; Education; Marine and Aerospace Applications N2 - Selective Laser Melting (SLM) is one of the Additive Manufacturing (AM) technologies applicable for producing complex geometries which are typically expensive or difficult to fabricate using conventional methods. This process has been extensively investigated experimentally for various metals and the fabrication process parameters have been established for different applications; however, fabricating 3D glass objects using SLM technology has remained a challenge so far although it could have many applications. This paper presents a summery on various experimental evaluations of a material database incorporating the build parameters of glass powder using the SLM process for jewelry applications. Y1 - 2014 SN - 978-0-7918-4583-7 U6 - https://doi.org/10.1115/ESDA2014-20380 SP - V001T06A005 ER - TY - CHAP A1 - Buda, Aurel A1 - Jozenfini, B. A1 - Wollert, Jörg T1 - Mobile ad-hoc Network for home automation based on ZigBee application framework T2 - 1st European ZigBee Developer's Conference : June 18 - 20, 2007, Munich, Germany Y1 - 2007 SP - 1 EP - 5 PB - Design & Elektronik CY - Poing ER - TY - CHAP A1 - Kilic, S. A. A1 - Raatschen, Hans-Jürgen A1 - Astaneh-Asl, A. A1 - Apaydin, N. M. T1 - Finite element modeling of the Fatih Sultan Mehmet Suspension Bridge T2 - Multi-Span Large Bridges - Proceedings of the International Conference on Multi-Span Large Bridges Y1 - 2015 SN - 9781138027572 SP - 1169 EP - 1173 PB - CRC Press CY - Leiden ER - TY - CHAP A1 - Wollert, Jörg T1 - Wireless systems for machinery safety : Requirements and solutions for wireless real time systems T2 - 16th International Conference on Research and Education in Mechatronics (REM), 2015 Y1 - 2015 SN - 978-3-945728-01-7 U6 - https://doi.org/10.1109/REM.2015.7380377 SP - 88 EP - 91 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 - https://doi.org/10.4271/2016-01-1611 SN - 1946-4002 ER - TY - BOOK A1 - Gebhardt, Andreas A1 - Hötter, Jan-Steffen T1 - Additive manufacturing : 3D printing for prototyping and manufacturing Y1 - 2016 SN - 978-1-56990-582-1 ; 978-1-56990-583-8 PB - Hanser Publishers CY - Munich ER - TY - JOUR A1 - Abbas, Karim A1 - Balc, Nicolae A1 - Bremen, Sebastian A1 - Skupin, Marco T1 - Crystallization and aging behavior of polyetheretherketone PEEK within rapid tooling and rubber molding JF - Journal of Manufacturing and Materials Processing N2 - In times of short product life cycles, additive manufacturing and rapid tooling are important methods to make tool development and manufacturing more efficient. High-performance polymers are the key to mold production for prototypes and small series. However, the high temperatures during vulcanization injection molding cause thermal aging and can impair service life. The extent to which the thermal stress over the entire process chain stresses the material and whether it leads to irreversible material aging is evaluated. To this end, a mold made of PEEK is fabricated using fused filament fabrication and examined for its potential application. The mold is heated to 200 ◦C, filled with rubber, and cured. A differential scanning calorimetry analysis of each process step illustrates the crystallization behavior and first indicates the material resistance. It shows distinct cold crystallization regions at a build chamber temperature of 90 ◦C. At an ambient temperature above Tg, crystallization of 30% is achieved, and cold crystallization no longer occurs. Additional tensile tests show a decrease in tensile strength after ten days of thermal aging. The steady decrease in recrystallization temperature indicates degradation of the additives. However, the tensile tests reveal steady embrittlement of the material due to increasing crosslinking. KW - additive manufacturing KW - fused filament fabrication KW - crystallization KW - polyetheretherketone KW - rapid tooling Y1 - 2022 U6 - https://doi.org/10.3390/jmmp6050093 SN - 2504-4494 N1 - The article belongs to the Special Issue Advances in Injection Molding: Process, Materials and Applications VL - 6 IS - 5 SP - 1 EP - 12 PB - MDPI CY - Basel ER - TY - CHAP A1 - Schmidt, Thomas A1 - Kasch, Susanne A1 - Eichler, Fabian A1 - Thurn, Laura T1 - Process strategies on laser-based melting of glass powder T2 - LiM 2021 proceedings N2 - This paper presents the laser-based powder bed fusion (L-PBF) using various glass powders (borosilicate and quartz glass). Compared to metals, these require adapted process strategies. First, the glass powders were characterized with regard to their material properties and their processability in the powder bed. This was followed by investigations of the melting behavior of the glass powders with different laser wavelengths (10.6 µm, 1070 nm). In particular, the experimental setup of a CO2 laser was adapted for the processing of glass powder. An experimental setup with integrated coaxial temperature measurement/control and an inductively heatable build platform was created. This allowed the L-PBF process to be carried out at the transformation temperature of the glasses. Furthermore, the component’s material quality was analyzed on three-dimensional test specimen with regard to porosity, roughness, density and geometrical accuracy in order to evaluate the developed L-PBF parameters and to open up possible applications. KW - 3D-printing KW - glass KW - additive manufactureing KW - laser based powder fusion Y1 - 2021 N1 - LiM (Lasers in Manufacturing) 2021, June 21 - 24, 2021, online ER - TY - JOUR A1 - Fateri, Miranda A1 - Gebhardt, Andreas A1 - Thümmler, Stefan A1 - Thurn, Laura T1 - Experimental investigation on selective laser melting of glass JF - Physics procedia : 8th International Conference on Laser Assisted Net Shape Engineering LANE 2014 Y1 - 2014 U6 - https://doi.org/10.1016/j.phpro.2014.08.118 SN - 1875-3892 (E-Journal); 1875-3884 (Print) VL - 56 (2014) SP - 357 EP - 364 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Abbas, Karim A1 - Thurn, Laura A1 - Kessler, Julia A1 - Eichler, Fabian T1 - Basic research of the consideration of additive manufactured lattice structures under thermoand fluid dynamic loads T2 - Modern technologies in manufacturing (MTeM 2019) Y1 - 2019 U6 - https://doi.org/10.1051/matecconf/201929901009 N1 - MATEC Web of Conferences 299; MTeM 2019 VL - 299 IS - Article 01009 ER - TY - CHAP A1 - Thurn, Laura A1 - Gebhardt, Andreas T1 - Arousing Enthusiasm for STEM: Teaching 3D Printing Technology T2 - Conference Proceedings: New Perspectives in Science Education Y1 - 2017 SN - 978-88-6292-847-2 SP - 87 EP - 92 PB - liberiauniversitaria.it CY - Padua ER - TY - CHAP A1 - Alhwarin, Faraj A1 - Ferrein, Alexander A1 - Gebhardt, Andreas A1 - Kallweit, Stephan A1 - Scholl, Ingrid A1 - Tedjasukmana, Osmond Sanjaya T1 - Improving additive manufacturing by image processing and robotic milling T2 - 2015 IEEE International Conference on Automation Science and Engineering (CASE), Aug 24-28, 2015 Gothenburg, Sweden Y1 - 2015 U6 - https://doi.org/10.1109/CoASE.2015.7294217 SP - 924 EP - 929 ER - TY - JOUR A1 - Haag, S. A1 - Zontar, D. A1 - Schleupen, Josef A1 - Müller, T. A1 - Brecher, C. T1 - Chain of refined perception in self-optimizing assembly of micro-optical systems JF - Journal of sensors and sensor systems N2 - Today, the assembly of laser systems requires a large share of manual operations due to its complexity regarding the optimal alignment of optics. Although the feasibility of automated alignment of laser optics has been shown in research labs, the development effort for the automation of assembly does not meet economic requirements – especially for low-volume laser production. This paper presents a model-based and sensor-integrated assembly execution approach for flexible assembly cells consisting of a macro-positioner covering a large workspace and a compact micromanipulator with camera attached to the positioner. In order to make full use of available models from computer-aided design (CAD) and optical simulation, sensor systems at different levels of accuracy are used for matching perceived information with model data. This approach is named "chain of refined perception", and it allows for automated planning of complex assembly tasks along all major phases of assembly such as collision-free path planning, part feeding, and active and passive alignment. The focus of the paper is put on the in-process image-based metrology and information extraction used for identifying and calibrating local coordinate systems as well as the exploitation of that information for a part feeding process for micro-optics. Results will be presented regarding the processes of automated calibration of the robot camera as well as the local coordinate systems of part feeding area and robot base. Y1 - 2014 U6 - https://doi.org/10.5194/jsss-3-87-2014 SN - 2194-878X VL - 3 IS - 1 SP - 87 EP - 95 PB - Copernicus Publ. CY - Göttingen ER - TY - JOUR A1 - Rieper, Harald A1 - Gebhardt, Andreas A1 - Stucker, Brent T1 - Selective Laser Melting of the Eutectic Silver-Copper Alloy Ag 28 wt % Cu JF - RTejournal - Forum für Rapid Technologie N2 - 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. KW - SLM KW - Response Surface Method KW - Porositat KW - Eutectic Silver Copper alloy KW - Additive Manufacturing Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?nbn:de:0009-2-44141 SN - 1614-0923 VL - 13 ER - TY - CHAP A1 - Kessler, Julia A1 - Balc, Nicolae A1 - Gebhardt, Andreas T1 - Basic research on lattice structures focused on the strut shape and welding beads T2 - Physics Procedia Y1 - 2016 U6 - https://doi.org/10.1016/j.phpro.2016.08.086 SN - 1875-3884 N1 - Laser Assisted Net Shape Engineering 9th International Conference on Photonic Technologies Proceedings of the LANE 2016 VL - Vol. 83 SP - 833 EP - 838 ER - TY - JOUR A1 - Michaux, F. A1 - Mattern, P. A1 - Kallweit, Stephan T1 - RoboPIV: how robotics enable PIV on a large industrial scale JF - Measurement Science and Technology N2 - 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. Y1 - 2018 U6 - https://doi.org/10.1088/1361-6501/aab5c1 SN - 1361-6501 N1 - Special Section on the 12th International Symposium on Particle Image Velocimetry (PIV 2017) VL - 29 IS - 7 SP - 074009 PB - IOP CY - Bristol ER - TY - JOUR A1 - Kunkel, Maximilian Hugo A1 - Gebhardt, Andreas A1 - Mpofu, Khumbaulani A1 - Kallweit, Stephan T1 - Statistical assessment of mechanical properties of selective laser melted specimens of stainless steel JF - The International Journal of Advanced Manufacturing Technology N2 - The rail business is challenged by long product life cycles and a broad spectrum of assembly groups and single parts. When spare part obsolescence occurs, quick solutions are needed. A reproduction of obsolete parts is often connected to long waiting times and minimum lot quantities that need to be purchased and stored. Spare part storage is therefore challenged by growing stocks, bound capital and issues of part ageing. A possible solution could be a virtual storage of spare parts which will be 3D printed through additive manufacturing technologies in case of sudden demand. As mechanical properties of additive manufactured parts are neither guaranteed by machine manufacturers nor by service providers, the utilization of this relatively young technology is impeded and research is required to address these issues. This paper presents an examination of mechanical properties of specimens manufactured from stainless steel through the selective laser melting (SLM) process. The specimens were produced in multiple batches. This paper interrogates the question if the test results follow a normal distribution pattern and if mechanical property predictions can be made. The results will be put opposite existing threshold values provided as the industrial standard. Furthermore, probability predictions will be made in order to examine the potential of the SLM process to maintain state-of-the-art mechanical property requirements. Y1 - 2018 U6 - https://doi.org/10.1007/s00170-018-2040-8 SN - 0268-3768 VL - 98 IS - 5-8 SP - 1409 EP - 1431 PB - Springer CY - London ER -