Now showing 1 - 10 of 38
  • Publication
    Resource efficient production of car body parts - implementation of digital twins across process chains
    ( 2022-09-21)
    Weber, Joshua
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    Sunderkoetter, Christina
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    Haase, Patrick
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    Hoefemann, Matthias
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    Joos, Paul
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    Merklein, Marion
    Sustainable production and environmentally friendly life cycle of every car is a main goal in the automotive industry. But there is a conflict between the rising demands of crash safety, the addition of components due to electric mobility and the reduction of weight. Car body parts can increase the crash safety and have a high lightweight construction potential. Especially tailor welded blanks made of multi-phase steel with a tensile strength of 1000 MPa, which are not established in car body parts, have the potential to improve the crash safety, save resources and lower the weight. The main challenge in the manufacturing of tailor welded blanks made of highest strength steel is the complex and expensive development. Due to the heat input and geometrical changes, the welding process affects the forming properties of the metal sheets. To evaluate the influence from different welding parameters to the forming process, a high number of expensive experiments must be repeated. This includes welding and forming parameter changes as well as adjustments to the forming tool. In order to make the development and manufacturing of tailor welded blanks made of highest strength steels more resource efficient, this work discusses the development and implementation of a digital and bidirectional twin in an industry-oriented environment. The objective is to demonstrate the data management based on the sheet metal properties, the change of properties due to laser welding simulated in Simufact Welding and the final forming process in AutoForm Forming. Additionally, the concept of a life cycle assessment of a tailor welded blank during these steps is developed. As summary the challenges, limitations, and improvements of the digital and bidirectional twin as replacement or, in addition to a consisting development process are discussed.
  • Publication
    Investigation of liquid metal embrittlement avoidance strategies for dual phase steels via electro-thermomechanical finite element simulation
    ( 2022-06) ;
    Böhne, Christoph
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    Meschut, Gerson
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    Modern advanced high-strength steel (AHSS) sheets used in automotive body construction are mostly zinc coated for corrosion resistance. The presence of zinc can cause cracking in steels due to liquid metal embrittlement (LME) during resistance spot welding (RSW). In combination with factors such as tensile strains, liquid zinc can lead to the formation of brittle, intergranular cracks in the weld and heat affected zone. While practical investigations to mitigate LME occurrence exist, the reason why a certain parameter might cause or prevent LME is often unknown. Numerical resistance spot welding simulation can visualize the underlying stresses, strains and temperatures during the welding process and investigate experimentally unmeasurable phenomena. In this work, a 3-dimensional electro-thermomechanical finite element approach is used to assess and investigate the critical parameters leading to LME occurrence. Experimentally observed crack sizes are correlated with the corresponding local strain rates and temperature exposure durations in the simulation. With this data, a map of LME occurrence over driving influence factors is drafted and discussed for effectiveness.
  • Publication
    Modellieren von Widerstandspunktschweissungen in FE
    In der Veröffentlichung wird anwendungsbezogen die Simulation von Widerstandpunktschweißungen in FEA-Programmen erklärt. Hierbei wird insbesondere der Nutzen für den praxisorientieren Schweißingenieur/Produktionsplaner erläutert und wie dieser die Schweißstruktursimulation nutzen kann, um Schweißverzug vorherzusagen und diesen zu minimieren.
  • Publication
    Conceptual Introduction of required development capabilities for Model-Based Systems Engineering
    ( 2021)
    Manoury, Marvin Michael
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    Zimmermann, Thomas C.
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    Stark, Rainer
    In the last years, multiple tools and methodologies have emerged that try to support the engineers to conduct Model Based Systems Engineering (MBSE). Nevertheless, the tools are usually bound to a certain methodology, which often requires sequential steps instead of supporting the iterative character of modern product development. In this paper, we conceptually introduce the development capabilities of the 5D model for MBSE as a convenient way to cover all relevant aspects of MBSE in an iterative way while being open to methodology and tool choice.
  • Publication
    Towards an AI-Enhanced Circular Economy. AI-enhanced identification, inspection and sorting for reverse logistics
    In terms of circular economy, remanufacturing ensures a high level of value recovery. After each life-cycle used products are returned to a remanufacturer for identification, inspection, sorting and reprocessing, ensuring the required quality for a next life cycle. This talk presents the project EIBA, funded by the German Federal Ministry of Education and Research, in which concepts to improve identification, inspection and sorting are developed and implemented by enhancing the sorting stations with sensor technology and AI on image and business data. First results show promising progress for AI-based visual recognition of used automotive components, also referred to as "cores".
  • Publication
    What dynamics should impedance-controlled robots render?
    ( 2019) ;
    Surdilovic, Dragoljub
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    While impedance control is the standard framework for physically interactive robots, the design choice of what dynamics should be rendered requires additional information (assumptions on environment, in-situ data). The range of dynamics which can be rendered by a robot is informed by its mechatronic design (actuators, physical compliance, innerloop control), and these mechanical design decisions must be made in advance. How can a mechatronic design be evaluated when the system objectives and environment dynamics are not quantified? This paper presents performance metrics proposed for pHRI in literature, and seeks to move towards a unified methodology for mechatronic design on interactive robots: supporting potential performance and safety over a set of environments.
  • Publication
    Herausforderungen in der Mikrozerspanung
    ( 2019)
    Kuche, Yves
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    Die Mikrozerspanung gewinnt aufgrund der wachsenden Märkte für Mikrokomponenten, Präzisionsbauteile und Bauteile mit Toleranzen im einstelligen Mikrometerbereich zunehmend an Bedeutung. Verfahren wie das Mikrodrehen, Mikrofräsen und Mikrobohren ermöglichen dabei die Fertigung von Bauteilen mit einer großen Geometriekomplexität in einem breiten Werkstoffspektrum, wodurch die Verfahren in Anwendungsfeldern wie dem Werkzeug- und Formenbau, der Mikrosystemtechnik, der Medizintechnik und der Feinwerktechnik nicht mehr wegzudenken sind. Bei der Mikrozerspanung nimmt der Einfluss des Schneidstoff- und Werkstückwerkstoffs, der Werkzeugmakro- und Werkzeugmikrogeometrie sowie der Prozesstechnologie im Vergleich zur Makrozerspanung deutlich zu. Grund dafür sind die im Vergleich zur Makrozerspanung geringeren Zustellungen und Schnitttiefen, welche aus den kleineren Werkzeugdimensionen resultieren. Weiterhin nimmt beispielsweise beim Mikrofräsen der Einfluss von Schwingungen erheblich zu und kann zu einem inhomogenen Prozess mit raschen Werkzeugversagen und einer schlechten Bauteilqualität resultieren. Innerhalb des Vortrags werden die grundlegenden Einflussgrößen bei der Mikrozerspanung erläutert und anhand von Beispielen und Untersuchungsergebnissen veranschaulicht. Durch aktuelle Ergebnisse aus der Grundlagen- sowie anwendungsorientierten Forschung werden weiterhin Einblicke in aktuelle Entwicklungsthemen gegeben, welche gemeinsam mit dem Fachpublikum diskutiert werden können. Diese beinhalten beispielsweise Erkenntnisse zum Einfluss der Werkzeugmikrogeometrie, Anforderungen bei der Zerspanung verschiedener Werkstoffe, dem Schwingungseinfluss sowie deren Analyse bei der Mikrozerspanung und die Potentiale verschiedener Schneidstoffe.