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Fraunhofer-Institut für Produktionsanlagen und Konstruktionstechnik IPK
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PublicationNumerical investigation into cleanability of support structures produced by powder bed fusion technology( 2022)
;Campana, Giampaolo ;Mele, Mattia ;Raffaelli, Luca ;Bergmann, AndréPurpose: Support structures used in laser powder bed fusion are often difficult to clean from unsintered powder at the end of the process. This issue can be significantly reduced through a proper design of these auxiliary structures. This paper aims to investigate preliminary the airflow within differently oriented support structures and to provide design guidelines to enhance their cleanability, especially the depowdering of them. Design/methodology/approach: This study investigates the cleanability of support structures in powder bed fusion technology. Digital models of cleaning operations were designed through computer-aided engineering systems. Simulations of the airflow running into the powder entrapped within the thin walls of auxiliary supports were implemented by computational fluid dynamics. This approach was applied to a set of randomly generated geometrical configurations to determine the air turbulence intensity depending on their design. Findings: The resul ts, which are based on the assumption that a relationship exists between turbulence and powder removal effectiveness, demonstrated that the maximum cleanability is obtainable through specific relative rotations between consecutive support structures. Furthermore, it was possible to highlight the considerable influence of the auxiliary structures next to the fluid inlet. These relevant findings establish optimal design rules for the cleanability of parts manufactured by powder bed fusion processes. Originality/value: This study presents a preliminary investigation into the cleanability of support structures in laser powder bed fusion, which has not been addressed by previous literature. The results allow for a better understanding of the fluid dynamics during cleaning operations. New guidelines to enhance the cleanability of support structures are provided based on the results of simulations. -
PublicationCharacterization and application of assistance systems in digital engineering( 2021)
;Stark, RainerA broad range of assistance systems can be found in manufacturing practice as well as in the corresponding literature. Similarly, it can be observed that there is a growing need for and an increasing supply of assistance systems of all kinds. However, for digital manufacturing, the assistance systems are not clearly characterized. The diversity in application areas and possible uses varies and there are no possibilities for comparison. This paper addresses the topic of assistance systems and examines the various basic elements of engineering activities in terms of possible types of assistance systems based on research in manufacturing industry. Crucial aspects of assistance capabilities for engineering are elaborated and possible digital approaches are validated based on investigations in the field of aircraft engine design and assembly. -
PublicationAnalysis of influencing factors for the dressing process in double side face grinding( 2021)Lichtschlag, LinusIn grinding, the design of the dressing process is an essential part of work preparation and restoration of the grinding wheel's profile and cutting ability. In contrast to most grinding processes, the choice of dressing parameters in double face grinding with planetary kinematics has so far only been experience-based. As a consequence, the dressing process causes a higher degree of tool wear than the machining of the workpieces. A focused design of the dressing process based on a scientific data could help to improve the ecological and the economic efficiency by reducing tool wear and the amount of dressing tools used. In this paper, methods for determining the wear condition and the result of the dressing process, including macro- and microscopic characteristic are presented. This includes a correlation analysis between parameters of wear characteristics and workpiece surface quality. Furthermore, technological investigations are carried out in order to systematically limit the main influencing factors on the dressing process. As a result, the parameters dresser grain size dgd, rotational speed ratio nld and the machined dresser height ∆hd are identified as significant for dressing. The knowledge about their principal influence on the dressing result could provide the basis for further research.
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PublicationResilienz durch dynamisches Prozessmanagement( 2021)
;Woesthoff, Julia ;Sala, Alessandro ;Lütkemeyer, MariusGaal, AlexanderKrisen treten regelmäßig auf und betreffen aufgrund zunehmender Globalisierung immer mehr Unternehmen gleichzeitig. In diesem Beitrag wird ein Ansatz für ein dynamisches Prozessmanagement vorgestellt, welches die Fähigkeit der Früherkennung von Disruptionen und gleichzeitig auch Routine sowie Agilität im Normal- wie auch im Krisenmodus durchgängig unterstützt. -
PublicationMBSE-Modellierung für Verhaltens- und Struktursimulation( 2021)Zimmermann, Thomasechnische Systeme werden mithilfe von Modellbasiertem Systems Engineering (MBSE) beschrieben, um eine domänenübergreifende Wissensbasis zu erzeugen, die es den beteiligten Stakeholdern ermöglicht, Systemelemente konsistent und parallel zu entwickeln. Die Qualität dieser Modelle ist maßgeblich dafür, wie effizient dieses Wissen aus dem MBSE auch zur Systemexploration verwendet werden kann, um Systemzusammenhänge zu analysieren, indem verschiedene Modellarten gemeinsam simuliert werden.
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PublicationSteuerung von Laser-induzierten periodischen Oberflächenstrukturen( 2021)
;Souza Schweitzer, Luiz Guilherme De ;Schneider, Peter ;Michel, AndreLaser-induzierte periodische Oberflächenstrukturen (LIPSS) weisen ein hohes Potenzial für Anwendungen in den Bereichen der Oberflächenfunktionalisierung auf. Die Steuerung der Richtung dieser Nanostrukturen kann nur durch Änderung der Laserpolarisation erfolgen. Auf dem Markt gibt es kein System zur automatischen Änderung der LIPSS-Orientierung. Für den industriellen Einsatz ist dies vom Vorteil, um Inhomogenität im Strukturverlauf zu vermeiden. In diesem Beitrag wird eine Systemlösung vorgestellt, indem die Steuerung der Richtung von Nanotexturen ermöglicht wird. -
PublicationAutomatisierte Erstellung von Virtual-Reality-Schulungen( 2021)
;Masuhr, ChristianKonkol, KathrinFür den effizienten Einsatz von Automatisierungstechnik ist qualifiziertes Instandhaltungspersonal notwendig, um operative Störungen schnell zu beheben. Diese Schulungen finden heutzutage entweder an realen Anlagen, oder auch bereits in eigens für bestimmte Anwendungsfälle entwickelte VR-Anwendungen statt. Zur Minimierung des Aufwands zur Erzeug von VR-Trainingssimulationen können jedoch bereits existierende Modelle und Simulationen aus dem Prozess der virtuellen Inbetriebnahme genutzt. Die Grundlage für das Training sind eine digitale Simulation und Vernetzung von realer Anlagensteuerung, Robotersteuerung und HMI-Schnittstellen. Dadurch können die Kosten reduziert und die Anzahl von unterschiedlichen Trainingsumgebungen skaliert werden. Die Trainingssimulation wird durch weitere motivierende Elemente erweitert. -
PublicationHyperconnected Ecosystems für industrielle Netzwerke( 2021)Das Hyperconnected Ecosystems für industrielle Netzwerke wird definiert als die Vernetzung aller relevanten Informationen und deren Erreichbarkeit jederzeit und von überall (hyperconnected). Barrieren zwischen Netzwerkpartnern bzgl. Datenbereitstellung und Zugriff werden reduziert und an aktuelle Anforderungen ausgerichtet. Die Evolution des Netzwerkes wird durch dessen dynamische Anpassbarkeit und flexible Einbindung von Diensten ermöglicht. Schlussendlich soll jede erforderliche Information an jedem Ort sofort in einer bearbeitbaren Form und möglichst ohne Aufwand verfügbar sein. Die Metapher des sozialen Netzwerks, in denen sich Partner finden und nach Bedarf Daten und Leistungen austauschen, dient als Basis für die Strukturen im Netzwerk. Dabei müssen industrielle Anforderungen nach Sicherheit, Souveränität und Transparenz integriert werden. Der Beitrag beschreibt die Vision eines Hyperconnected Ecosystem für industrielle Netzwerke und erste Ansätze zu dessen Umsetzung.
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PublicationElectrical discharge dressing of honing stones( 2020)
;Yabroudi, Sami ;Zimmermann, Sascha ;Gerlitzky, Georg ;Klink, UlrichSihling, BerndHoning processes require a systematic preparation and a regeneration of the honing tool to guarantee a sufficient cutting behaviour and prevent unintended wear of the tool. These dressing processes are particularly important for the regeneration of the macro- and microscopic topography of the honing stones. The established method of manual shaping subsequent to a cylindrical grinding process demands a high skill level, a great amount of non-productive time and is not reproducible. In this paper the preparation of honing stones by use of electrical discharge machining (EDM) is presented. The aim is to ensure an automatic, systematic and reproducible process of resetting the bond of honing stones. Different tool electrode materials were analysed systematically for two different bond specifications of the honing stones. EDM process parameters were studied within a design of experiments (DoE) strategy and a subsequent effect analysis to assure the identification of most appropriate EDM process parameters. After this procedure various cycles of long-stroke honing processes were carried out. As a result, the new approach makes it possible to prepare honing stones with reproducible sharpness and macroscopic topography within an automated process. The dressing time td was reduced by 88 % compared to the established method. -
PublicationInfluence of the fatty acid profile on the lubricating film formation in micro-milling process on 7050-T7451 aluminum alloy( 2020)
;Chanes de Souza, Milena ;Wiesner, Hagen Maximilian ;De Oliveira Gomes Júnior, JeffersonThis work studies the technical performance of vegetable-based metalworking fluids as a more environment-friendly alternative for micro-milling on 7050-T7451 aluminum alloy. Micro-milling investigations were performed using two vegetable-based oils, two emulsions prepared with the same vegetable-based oil and a commercial emulsion for comparison. It was noted that the vegetable-based oils with high oleic fatty acid profile provide better lubrication films than mid-oleic fatty acid profiles. However, the wear of the cutting tools is slightly more pronounced when the high oleic oil was used. When these oils were used for the preparation of vegetable-based emulsions, the high oleic emulsion presents better lubricating potential and provides high surface quality than the mid-oleic emulsion. However, the wear of the cutting tool was similar. The vegetable-based metalworking fluids showed similar performance than the commercial reference. Therefore, the oil with high oleic fatty acid profiles presents good technical performance and can be used in vegetable-based metalworking fluids formulations.