TY - JOUR A1 - Luft, Angela A1 - Bremen, Sebastian A1 - Luft, Nils T1 - A cost/benefit and flexibility evaluation framework for additive technologies in strategic factory planning JF - Processes N2 - There is a growing demand for more flexibility in manufacturing to counter the volatility and unpredictability of the markets and provide more individualization for customers. However, the design and implementation of flexibility within manufacturing systems are costly and only economically viable if applicable to actual demand fluctuations. To this end, companies are considering additive manufacturing (AM) to make production more flexible. This paper develops a conceptual model for the impact quantification of AM on volume and mix flexibility within production systems in the early stages of the factory-planning process. Together with the model, an application guideline is presented to help planners with the flexibility quantification and the factory design process. Following the development of the model and guideline, a case study is presented to indicate the potential impact additive technologies can have on manufacturing flexibility Within the case study, various scenarios with different production system configurations and production programs are analyzed, and the impact of the additive technologies on volume and mix flexibility is calculated. This work will allow factory planners to determine the potential impacts of AM on manufacturing flexibility in an early planning stage and design their production systems accordingly. KW - additive manufacturing KW - factory planning KW - manufacturing flexibility KW - volume flexibility KW - mix flexibility Y1 - 2023 U6 - https://doi.org/10.3390/pr11071968 SN - 2227-9717 VL - 11 IS - 7 PB - MDPI CY - Basel ER - TY - CHAP A1 - Luft, Angela A1 - Gebhardt, Andreas A1 - Balc, Nicolae T1 - Challenges of additive manufacturing in production systems T2 - Modern technologies in manufacturing (MTeM 2019) Y1 - 2019 U6 - https://doi.org/10.1051/matecconf/201929901003 N1 - MATEC Web of Conferences 299; MTeM 2019 VL - 299 IS - Article 01003 ER - TY - JOUR A1 - Luft, Angela A1 - Luft, Nils A1 - Arntz, Kristian T1 - A basic description logic for service-oriented architecture in factory planning and operational control in the age of industry 4.0 JF - Applied Sciences N2 - Manufacturing companies across multiple industries face an increasingly dynamic and unpredictable environment. This development can be seen on both the market and supply side. To respond to these challenges, manufacturing companies must implement smart manufacturing systems and become more flexible and agile. The flexibility in operational planning regarding the scheduling and sequencing of customer orders needs to be increased and new structures must be implemented in manufacturing systems’ fundamental design as they constitute much of the operational flexibility available. To this end, smart and more flexible solutions for production planning and control (PPC) are developed. However, scheduling or sequencing is often only considered isolated in a predefined stable environment. Moreover, their orientation on the fundamental logic of the existing IT solutions and their applicability in a dynamic environment is limited. This paper presents a conceptual model for a task-based description logic that can be applied to factory planning, technology planning, and operational control. By using service-oriented architectures, the goal is to generate smart manufacturing systems. The logic is designed to allow for easy and automated maintenance. It is compatible with the existing resource and process allocation logic across operational and strategic factory and production planning. KW - manufacturing data model KW - production planning and control KW - manufacturing flexibility KW - technology planning KW - SOA KW - service-oriented architectures KW - factory planning Y1 - 2023 U6 - https://doi.org/10.3390/app13137610 SN - 2076-3417 N1 - This article belongs to the Special Issue "Smart Industrial System" VL - 2023 IS - 13 PB - MDPI CY - Basel ER - TY - BOOK A1 - Mautner, Karin T1 - Numerical treatment of the Black-Scholes variational inequality in computational finance Y1 - 2006 N1 - Humboldt-Univ., Diss CY - Berlin ER - TY - JOUR A1 - Mautner, Karin A1 - Forster, Ralf A1 - Kornhuber, Ralf A1 - Sander, Oliver T1 - Fast and Reliable Pricing of American Options with Local Volatility / Forster, Ralf ; Kornhuber, Ralf ; Mautner, Karin ; Sander, Oliver JF - Domain Decomposition Methods in Science and Engineering XVII Y1 - 2008 SN - 978-3-540-75198-4 N1 - Lecture Notes in Computational Sciece and Engineering ; 60 SP - 383 EP - 390 ER - TY - CHAP A1 - Merten, Sabine A1 - Conrad, Thorsten A1 - Kämper, Klaus-Peter A1 - Picard, Antoni A1 - Schütze, Andreas T1 - Virtual Technology Labs - an efficient tool for the preparation of hands-on-MEMS-courses in training foundries N2 - Hands-on-training in high technology areas is usually limited due to the high cost for lab infrastructure and equipment. One specific example is the field of MEMS, where investment and upkeep of clean rooms with microtechnology equipment is either financed by production or R&D projects greatly reducing the availability for education purposes. For efficient hands-on-courses a MEMS training foundry, currently used jointly by six higher education institutions, was established at FH Kaiserslautern. In a typical one week course, students manufacture a micromachined pressure sensor including all lithography, thin film and packaging steps. This compact and yet complete program is only possible because participants learn to use the different complex machines in advance via a Virtual Training Lab (VTL). In this paper we present the concept of the MEMS training foundry and the VTL preparation together with results from a scientific evaluation of the VTL over the last three years. KW - Virtuelles Laboratorium KW - Virtuelles Labor KW - Hand-on-training KW - Virtual Technology Lab KW - MEMS ; education and training foundry Y1 - 2006 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 - Mukherjee, Krishnendu A1 - Prahl, Ulrich A1 - Bleck, Wolfgang A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Abdurakhmanov, Aydemir T1 - Characterization and modelling techniques for gas metal arc welding of DP 600 sheet steels JF - Materialwissenschaft und Werkstofftechnik N2 - The objectives of the present work are to characterize the Gas Metal Arc Welding process of DP 600 sheet steel and to summarize the modelling techniques. The time-temperature evolution during the welding cycle was measured experimentally and modelled with the softwaretool SimWeld. To model the phase transformations during the welding cycle dilatometer tests were done to quantify the parameters for phase field modelling by MICRESS®. The important input parameters are interface mobility, nucleation density, etc. A contribution was made to include austenite to bainite transformation in MICRESS®. This is useful to predict the microstructure in the fast cooling segments. The phase transformation model is capable to predict the microstructure along the heating and cooling cycles of welding. Tensile tests have shown the evidence of failure at the heat affected zone, which has the ferrite-tempered martensite microstructure. Y1 - 2010 U6 - https://doi.org/10.1002/mawe.201000692 SN - 1521-4052 VL - 41 IS - 11 SP - 972 EP - 983 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Mukherjee, Krishnendu A1 - Ramazani, Ali A1 - Yang, Li A1 - Prahl, Ulrich A1 - Bleck, Wolfgang A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Abdurakhmanov, Aydemir T1 - Characterization of gas metal arc welded hot rolled DP600 steel JF - Steel research international Y1 - 2011 SN - 1869-344X (E-Book); 1611-3683 (Print) VL - Vol. 82 IS - Iss. 12 SP - 1408 EP - 1416 PB - Wiley CY - Weinheim 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 - 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 - Pak, Daniel A1 - Piegeler, D. A1 - Feldmann, Markus A1 - Schleser, Markus A1 - Dilthey, Ulrich ED - Hegger, Josef T1 - Hybrid joints of textile reinforced concrete parts - designed for assembly T2 - Textile reinforced concrete : proceedings of the 1. International RILEM Conference, held at the RWTH Aachen, September 6/7, 2006. (RILEM proceedings ; 50) Y1 - 2006 SN - 2-912143-97-7 SP - 181 EP - 190 PB - RILEM Publ. CY - Bagneux ER - TY - JOUR A1 - Panc, Nicolae A1 - Contiu, Glad A1 - Bocanet, Vlad A1 - Thurn, Laura A1 - Sabau, Emilia T1 - The influence of cutting technology on surface wear hardness JF - Academic Journal of Manufacturing Engineering Y1 - 2019 SN - 1583-7904 VL - 17 IS - 3 SP - 205 EP - 210 ER - TY - CHAP A1 - Peeken, Heinz A1 - Troeder, Christoph A1 - Benner, Joachim A1 - Platt, Werner T1 - A new approach to describe the mechanical performance of flexible couplings in drive systems T2 - Proceedings of the International Conference on Rotordynamics : September 14 - 17, 1986, Tokyo Y1 - 1986 N1 - International Conference on Rotordynamics <1986, Tōkyō> SP - 159 EP - 163 PB - IFToMM CY - Tokyo ER - TY - THES A1 - Pfaff, Raphael T1 - Evaluation and extension of the potential for application of the behavioural framework to practical engineering problems Y1 - 2013 N1 - Coventry, Univ., Diss., 2013 ER - TY - THES A1 - Pfaff, Raphael T1 - Automated processing of the ISL Doppler images Y1 - 2007 N1 - Hagen, Fernuniv., Bachelorarbeit, 2007 ER - TY - THES A1 - Pfaff, Raphael T1 - Modelling of nonlinear systems using piecewise defined models Y1 - 2006 N1 - Coventry, Univ., Masterarbeit, 2006 ER - TY - CHAP A1 - Pfaff, Raphael T1 - Analysis of Big Data Streams to obtain Braking Reliability Information for Train Protection systems T2 - Asia-Pacific Conference of the Prognostics and Health Management Society Y1 - 2017 N1 - Asia-Pacific Conference of the Prognostics and Health Management Society, Jeju, Korea 2017 SP - 1 EP - 7 ER - TY - JOUR A1 - Pfaff, Raphael T1 - Braking distance prediction for vehicle consist in low-speed on-sight operation: a Monte Carlo approach JF - Railway Engineering Science N2 - The first and last mile of a railway journey, in both freight and transit applications, constitutes a high effort and is either non-productive (e.g. in the case of depot operations) or highly inefficient (e.g. in industrial railways). These parts are typically managed on-sight, i.e. with no signalling and train protection systems ensuring the freedom of movement. This is possible due to the rather short braking distances of individual vehicles and shunting consists. The present article analyses the braking behaviour of such shunting units. For this purpose, a dedicated model is developed. It is calibrated on published results of brake tests and validated against a high-definition model for low-speed applications. Based on this model, multiple simulations are executed to obtain a Monte Carlo simulation of the resulting braking distances. Based on the distribution properties and established safety levels, the risk of exceeding certain braking distances is evaluated and maximum braking distances are derived. Together with certain parameters of the system, these can serve in the design and safety assessment of driver assistance systems and automation of these processes. KW - Freight rail KW - Shunting KW - Braking curves KW - Brake set-up KW - Driver assistance system Y1 - 2023 U6 - https://doi.org/10.1007/s40534-023-00303-7 SN - 2662-4753 (eISSN) SN - 2662-4745 (Print) VL - 31 IS - 2 SP - 135 EP - 144 PB - SpringerOpen ER - TY - CHAP A1 - Pfaff, Raphael A1 - Burnham, Keith J. T1 - On abstraction and interpretability: a behavioural perspective T2 - 19th International Conference on Systems Engineering 2008 : ICSENG '08 : 19 - 21 Aug. 2008, University of Nevada, Las Vegas, Nevada Y1 - 2008 SN - 978-0-7695-3331-5 ; 978-0-7695-2719-2 SP - 89 EP - 94 PB - IEEE CY - Piscataway, NJ ER -