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PublicationFully coupled wet cylindrical turning simulation using the Finite-Pointset-Method( 2021)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.
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PublicationData for a simulation of metal cutting with cutting fluid using the Finite-Pointset-Method( 2021)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.
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PublicationDeutsche Normungsroadmap Künstliche Intelligenz(DIN, 2020)
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PublicationOptimization with the evolution strategy by example of electrical-discharge drilling( 2020)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.
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PublicationUnified information access in product creation with an integrated control desk( 2017)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.
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PublicationKonzepte und Implikationen zur Integration von VR-, CAx- und PDM-Systemen für die funktionale Absicherung von Montage-/Demontageoperationen( 2010)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.
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PublicationInvestigating three-dimensional sketching for early conceptual design - results from expert discussions and user studies( 2009)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.
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PublicationWissen und Information 2005(Fraunhofer IRB Verlag, 2005)Die Studie der Fraunhofer-Wissensmanagement Community legt Ergebnisse über den aktuellen Entwicklungsstand von Wissensmanagement vor und zeigt zukünftige Herausforderungen in Unternehmen auf. Im Rahmen einer Online Befragung im Oktober und November 2004 gaben 540 Unternehmen im deutschsprachigen Raum Auskunft zu ihren aktuellen und geplanten Wissensmanagement-Aktivitäten. Dabei standen folgende Fragen im Fokus der Studie: Welche Instrumente des Wissensmanagements werden aktuell in Unternehmen angewendet? Welche Dimension des Wissensmanagement-Dreiecks (Mensch, Organisation und Technologie) wird derzeit von Unternehmen vorangetrieben? Welches Lösungspotenzial wird dem diffusen Begriff "Wissensmanagement" zugesprochen? Welche Bedeutung hat Wissensmanagement in Zukunft? Die Studie gliedert sich nach den Gestaltungsdimensionen des Wissensmanagements in einen humanbezogenen, einen organisationalen und einen technologieorientierten Teil. Darüber hinaus werden allgemeine Aussagen zur aktuellen Nutzung von Wissensmanagement getroffen und lurz der theoretische Hintergrund beleuchtet. Erkannte Trends in den einzelnen Studienteilen werden zu einem abschließenden Bild verdichtet.
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PublicationInViS - Integrierter Virtueller Schiffbau( 2004)Der Beitrag stellt wesentliche Ergebnisse des BMBF-Projekts InViS - Integrierter Virtueller Schiffbau vor. Hierzu zählen das als XML-Schema codierte Datenmodell, die offene Integrationsplattform sowie verschiedene darauf aufbauende Komponenten für Telekooperation, VR-Präsentation, Simulation und Anbindung von CAD-Systemen. Die Projektergebnisse werden im Kontext des Virtuellen Maschinenraums in zwei Anwendungsszenarien evaluiert und verdeutlichen das Potential des integrativen Ansatzes zur Unterstützung durchgängiger Prozessketten.
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PublicationAspekte des Virtual Engineering im Schiffbau( 2004)Der Beitrag stellt wesentliche Ergebnisse aus dem BMBF-Projekt InViS -- Integrierter Virtueller Schiffbau vor. Hierzu zählen das als XML-Schema codierte Datenmodell, die offene Integrationsplattform sowie verschiedene darauf aufbauende Komponenten für Telekooperation, VR-Präsentation, Simulation und Anbindung von CAD-Systemen. Die Projektergebnisse werden im Kontext des Virtuellen Maschinenraums in zwei Anwendungsszenarien evaluiert und verdeutlichen das Potential des integrativen Ansatzes zur Unterstützung durchgängiger Prozessketten.
