Now showing 1 - 10 of 30
  • Publication
    Data for a simulation of metal cutting with cutting fluid using the Finite-Pointset-Method
    ( 2021) ;
    Barth, Enrico
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    Seifarth, Tobias
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    Höchel, Maximilian
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    Eisenträger, Almut
    The measurement and simulation data, their preparation and the simulation setup published in this co-submission are related to the article ""Simulation of metal cutting with cutting fluid using the Finite-Pointset-Method"". Wet and dry turning experiments were conducted at the Institute for Machine Tools and Factory Management(IWF), Berlin, Germany. Required adaptions of the used software MESHFREE were performed at Fraunhofer ITWM, Kaiserslautern, Germany. Both institutes collaboratively developed and validated the orthogonal cutting simulation model using the Finite-Pointset-Method (FPM). In this paper all measurement and simulation data and their preparation methods are presented in detail. This includes the preparation methods of process forces, analysis of chip morphology images as well as measured contact lengths on tool rake faces. Moreover, the experimental and simulation data are provided at the Mendeley Data repository. Hence the reader can use the data for own validations and analysis. Furthermore, the used simulation model files are completely published at the Mendeley Data repository. It allows the reader to retrace all settings. In addition, this enables to repeat the simulations and to simulate other process parameter combinations according to own interests.
  • Publication
    Fully coupled wet cylindrical turning simulation using the Finite-Pointset-Method
    ( 2021) ;
    Barth, Enrico
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    Quellhorst, Alexander
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    Seifarth, Tobias
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    Nabbout, Kaissar
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    Sommerfeld, Martin
    In industrial machining operations, many turning processes are carried out under wet conditions. In contrast, most simulation tools are only suitable for dry cutting processes due to challenges of modeling fluid-structure-interactions (FSI). In this paper, a wet, fully coupled cutting simulation using the Finite-Pointset-Method (FPM) is presented and validated for industrially relevant cylindrical turning. To facilitate the required reduction of the calculation effort, different routines like adaptive numerical discretization are applied. The results indicate different cutting fluid effects like evaporation areas around the chip.
  • Publication
    Deutsche Normungsroadmap Künstliche Intelligenz
    Die deutsche Normungsroadmap Künstliche Intelligenz (KI) verfolgt das Ziel, für die Normung Handlungsempfehlungen rund um KI zu geben, denn sie gilt in Deutschland und Europa in fast allen Branchen als eine der Schlüsseltechnologien für künftige Wettbewerbsfähigkeit. Die EU geht davon aus, dass die Wirtschaft in den kommenden Jahren mit Hilfe von KI stark wachsen wird. Umso wichtiger sind die Empfehlungen der Normungsroadmap, die die deutsche Wirtschaft und Wissenschaft im internationalen KI-Wettbewerb stärken, innovationsfreundliche Bedingungen schaffen und Vertrauen in die Technologie aufbauen sollen.
  • Publication
    Optimization with the evolution strategy by example of electrical-discharge drilling
    ( 2020) ;
    Koref, Ivan Santibáñez
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    Rechenberg, Ingo
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    A key challenge in electrical discharge machining (EDM) is to find a suitable combination out of numerous process parameters. Any changes concerning the electrode materials or geometries require newly optimized technologies. These technologies are to be developed from a considerable number of experiments which must be carried out by an experienced operator. This paper presents a new method of finding the optimal set of parameters. Here, the performance of the evolution strategy (ES), a stochastic, metaheuristic optimization method, is investigated. It offers the great advantage of finding solutions, even with little knowledge of system behaviour. The method involved a randomized and a derandomized ES, based on a non-elitist (m,l)-ES with one parent and four children. The two ES were initialized from an unfavourable starting point (A) and from a favourable starting point (B) to investigate their effectiveness. It could be demonstrated that starting from the unfavourable starting point A the erosion duration tero could be reduced by a maximum of 77% with a slightly smaller linear wear of the tool electrode DlE after 40 trials.
  • Publication
    Unified information access in product creation with an integrated control desk
    ( 2017)
    Wrasse, Kevin
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    Hayka, Haygazun
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    Stark, Rainer
    Customers demand for individualized products leads to a large variety of different products in small series and single-unit production. A high flexibility pressure in product creation is one result of this trend. In order to counteract the pressure, the information steadily increasing by Industry 4.0 must be made available at the workplace. Additionally, a better exchange of information between product development, production planning and production is necessary. The improvement of individual systems, like CAD, PDM, ERP and MES, can only achieve this to a limited extent. Since they mostly use systems from different manufacturers, the necessary deeper integration of information is only feasible for SMEs to a limited extend. The presented control desk helps to ensure a more flexible product creation as well as information exchange. It captures information from different IT systems in the production process and presents them integrated, task-oriented and oriented to the user's mental model, e.g. information of the production combined with the 3D model of product parts, or information about product development on the 3D model of the production. The solution is a digital 3D model of the manufacturing environment, which is enriched by billboards for a quick information overview and web service windows to access detailed MES and PDM information. By this, the level of abstraction can be reduced and reacts to changed requirements in the short term, making informed decisions. The interaction with the control stands utilizes the touch skills of mobile and fixed systems such as smartphones, tablets and multitouch tables.
  • Publication
    Decision-making support for sustainable product creation
    ( 2012)
    Inoue, Masato
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    Stark, Reiner
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    Tanaka, Kenji
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    Nahm, Yoon-Eui
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    Ishikawa, Haruo
    A satisfactory multiobjective design that incorporates physical performance as well as sustainability is necessary from a global environmental protection perspective. For obtaining sustainable lifecycles, decision making in the early phases of the design process, considering multiple sources of uncertainty, is important. Previously, we proposed a preference set-based design (PSD) by Inoue et al. (2010) [16] method, which enables a flexible and robust design under various sources of uncertainty while capturing the designers preference based on his/her knowledge or experience. The present study focuses on a decision-making support for sustainable product creation in the early phases of the design process considering the various design uncertainties. We investigate different officially accepted sustainability indicators and identify the ones that are related to the product development process by considering the physical performance and sustainability of the products concurrently. Thereafter, the proposed method is applied to a multiobjective design problem. This paper discusses the applicability of PSD as a decision-making support method for sustainable development using the design of an alternator as an example.
  • Publication
    Entwicklung der netzfreien Finite-Pointset-Methode für die Zerspansimulation
    ( 2011)
    Uhlmann, E.
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    Gerstenberger, R.
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    Schäfer, M.
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    Kuhnert, J.
    Aktuelle Programme für die Finite-Elemente-Simulation von Zerspanprozessen verwenden Neuvernetzungsprozeduren, um die Trennung von Span und Grundwerkstoff abzubilden und die in den Scherzonen auftretenden großen Elementverzerrungen zu korrigieren. Diese Prozeduren schränken jedoch die Abbildungsgenauigkeit auf Grund von Interpolationsverlusten ein. Eine netzfreie Simulationsmethode ohne Neuvernetzungsprozeduren kann daher für die Zerspansimulation vorteilhaft sein. Im Rahmen der Weiterentwicklung der netzfreien Finite-Pointset-Methode (FPM) für die Zerspansimulation wurden ein Materialmodell für metallische Werkstoffe implementiert, Spanbildungssimulationen mit unterschiedlichen Werkstoffen durchgeführt und erste Schritte zur Darstellung des Kühlschmierstoffs in der Zerspansimulation unternommen.
  • Publication
    A contour matching algorithm to reconstruct ruptured documents
    ( 2010)
    Stieber, A.
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    Schneider, J.
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    Nickolay, B.
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    Krüger, J.
    A procedure for reassembling ruptured documents from a large number of fragments is proposed. Such problems often arises in forensic and archiving. Usually, fragments are mixed and take arbitrary shapes. The proposed procedure concentrates on contour information of the fragments and represents it as feature strings to perform a matching based on dynamic programming. Experiments with 500 images of randomly shredded fragments show that the proposed reconstruction procedure is able to compose nearly 98% of the ruptured pages.
  • Publication
    Konzepte und Implikationen zur Integration von VR-, CAx- und PDM-Systemen für die funktionale Absicherung von Montage-/Demontageoperationen
    ( 2010)
    Wöhler, T.
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    Wolter, L.
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    Rothenburg, U.
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    Strauchmann, M.
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    Mader, S.
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    Haupt, M.
    Die Erstellung virtueller Montage- und. Demontageprozesse ist ein komplexer und zeitaufwendiger Prozess, der derzeit durch einen hohen manuellen Aufwand gekennzeichnet ist. In diesem Beitrag werden Ergebnisse des Forschungsprojekts AVILUSplus vorgestellt, die darauf abzielen, virtuelle Montage- und Demontageprozesse auf der Grundlage von existierenden Informationen als Teil der Absicherung von zu entwickelnden Produkten im Rahmen der Virtuellen Produktentstehung effizienter in deren Prozessketten zu integrieren. Dazu wurden Methoden und Werkzeuge entwickelt, um CAD-Modelle für diesen Zweck aufzubereiten und notwendige geometriebezogene Informationen aus den Modellen zu extrahieren. Auf der Grundlage von Bauteilgeometrie und -physik werden Montage- und Demontagepfade erzeugt. Die zugehörigen Handlungsanweisungen werden entsprechend ihrer Handlungssemantik formuliert und mit Verknüpfungen zu Baugruppenstrukturen und Werkzeugen versehen. Die Integration der Modelle und Werkzeuge in PLM-Strukturen und -Prozesse ermöglicht deren durchgängige Nutzung im Produktentwicklungsprozess und führt zu einer engeren Integration von VR/AR-Anwendungen zur virtuellen Absicherung. Die entwickelten Verfahren werden in einen gemeinsamen Demonstrator integriert, welcher im Rahmen dieses Dokuments vorgestellt wird.
  • Publication
    Investigating three-dimensional sketching for early conceptual design - results from expert discussions and user studies
    ( 2009)
    Israel, J.H.
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    Wiese, E.
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    Mateescu, M.
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    Zöllner, C.
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    Stark, R.
    As immersive 3D user interfaces reach broader acceptance, their use as sketching media is attracting both commercial and academic interests. So far, little is known about user requirements and cognitive aspects of immersive 3D sketching. Also the latter's integration into the workflow of virtual product development is far from being solved. We present results from two focus group expert discussions, a comparative user study on immersive 3D sketching conducted among professional furniture designers and a qualitative content analysis of user statements. The results of the focus group discussions show a strong interest in using the three-dimensional (3D) space as a medium for conceptual design. Users expect it to provide new means for the sketching process, namely spatiality, one-to-one proportions, associations, and formability. Eight groups of functions required for 3D sketching were outlined during the discussions. The comparative study was intended to find and investigate advantages of immersive three-dimensional space and its additional degrees-of-freedom for creative/reflective externalization processes. We compared a 3D and a 2D baseline condition in the same technical environment, a VR-Cave system. In both conditions, no haptic feedback was provided and the 2D condition was not intended to simulate traditional 2D sketching (on paper). The results from our user study show that both the sketching process and the resulting sketches differ in the 2D and 3D condition, namely in terms of the perceived fluency of sketch creation, in terms of the perceived appropriateness for the task, and in terms of the perceived stimulation by the medium, the movement speed, the sketch sizes, the degree of detail, the functional aspects, and the usage time. In order to validate the results of the focus group discussions, we produced a questionnaire to check for the subjectively perceived advantages and disadvantages in both the 2D and 3D conditions. A qualitative content analysis of the user statements revealed that the biggest advantage of 3D sketching lies in the sketching process itself. In particular, the participants emphasized the system's ability to foster inspiration and to improve the recognition of spatiality and spatial thinking. We argue that both 2D and 3D sketching are relevant for early conceptual design. As we progress towards 3D sketching, new tangible interactive tools are needed, which account for the user's perceptual and cognitive abilities.