University of Siegen
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Publication Ein datengetriebenes Verfahren zur robusten und zuverlässigen Auslegung des Niederdruck-Kokillen-Gießprozesses(2026)Diese Arbeit demonstriert einen datengetriebenen Ansatz zur effizienten Ermittlung eines robusten und zuverlässigen Arbeitspunkts im Niederdruck-Kokillen-Gießprozess. Durch dynamische Versuchsplanung, Modellierung und Optimierung werden im Rahmen der Prozessauslegung Parameterkombinationen identifiziert, die die Ausschusswahrscheinlichkeit und die Zykluszeit unter Berücksichtigung von Unsicherheiten minimieren.Source Type:Doctoral ThesisSeries:Forschungsberichte des Lehrstuhls für Umformtechnik21 13 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Open Access , Ein datengetriebenes Verfahren zur robusten und zuverlässigen Auslegung des Niederdruck-Kokillen-Gießprozesses(2026)Ensuring product quality while maintaining high productivity and energy efficiency are key aspects and therefore levers for optimization measures in companies. In many sectors, including light metal foundries, data-driven methods based on machine learning are already being used in the context of Industry 4.0 to continuously improve process efficiency. Many studies are focused on analyzing process data during serial production. A holistic, data-based strategy for determining a robust and reliable process design that considers any process fluctuations that occur has not yet been developed for low pressure die casting. This paper therefore presents a novel, automated method for determining a robust and reliable operating point during the development phase of the low pressure die casting process. The focus is on the process parameters for a given casting and mold design but can easily be extended to include design parameters. Within the framework of design of experiments, the procedure includes the needs-based adjustment of the number of experiments as well as compliance with input and output restrictions, the modelling of both static and dynamic system behavior and, within the multi-criteria optimization, the consideration of both uncertainties in the process parameters and uncertainties due to limited metrological accessibility. A selection mechanism, which supports the user in the rapid analysis of robust and reliable Pareto-optimal solutions, rounds off the procedure. The performance is demonstrated using a real low pressure die casting process at MARTINREA HONSEL GERMANY GMBH. The results show that the approach enables a robust and reliable casting process design with comparatively low energy input, considering the boundary conditions of short cycle times.Source Type:Doctoral ThesisSeries:Forschungsberichte des Lehrstuhls für UmformtechnikVolume number:2111 18 - Some of the metrics are blocked by yourconsent settings
Publication Datengestützte Umformtechnik: Künstliche Intelligenz zwischen Prozesswissen, Regelung und Produktionsrealität(2026)With the 7th Biegeforum, the Chair of Forming Technology at the University of Siegen once again offers researchers the opportunity to present their topics and findings to a specialist audience from industry and academia. This conference volume brings together current research findings and innovative developments in forming technology, highlighting the broad scope of the research field. The Biegeforum thus underscores its role as a key platform for exchange between research and industry — a role it has fulfilled since its first edition in 2011.Source Type:Conference ProceedingsSeries:Forschungsberichte des Lehrstuhls für Umformtechnik4 5 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Open Access , Datengestützte Umformtechnik: Künstliche Intelligenz zwischen Prozesswissen, Regelung und ProduktionsrealitätWith the 7th Biegeforum, the Chair of Forming Technology at the University of Siegen once again offers researchers the opportunity to present their topics and findings to a specialist audience from industry and academia. This conference volume brings together current research findings and innovative developments in forming technology, highlighting the broad scope of the research field. The Biegeforum thus underscores its role as a key platform for exchange between research and industry — a role it has fulfilled since its first edition in 2011.Source Type:Conference ProceedingsSeries:Forschungsberichte des Lehrstuhls für Umformtechnik7 12 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Open Access , Design and Development of Hybrid Tools for Rotary Draw Bending Using Digital Twin and Additive Manufacturing Processes(2026)Rotary draw bending (RDB) process is a profile bending process mostly used in industrial practices for bending metal tubes. Presently, RDB process is conducted by using geometry specific bending tools. The fundamental tools used in RDB process are pressure-die, bend-die, clamp-dies, wiper-die, collet and mandrel. These tools have simplified geometries with a semi-circular tool surface which corresponds to only one specific tube diameter. This makes RDB process inflexible because different tube diameters cannot be used with a specific set of bending tools. In addition to process-flexibility, the modern production regime of present era needs bending tools to be cost effective and light weight. This doctoral thesis is aimed to utilize modern manufacturing techniques, i.e., 3D printing processes and digital twin of RDB process, to develop the geometric design of bending tools which should be cost effective, light weight and provides process-flexibility to RDB process. A digital twin of the RDB process is developed and the accuracy of the digital twin is verified by comparing the FE-simulation results with practically conducted experiments. The design factors which critically influence the tool design are identified through digital twin prototyping. The digital twin prototyping method encompasses systematic development and testing of 3D printed polymeric tools in RDB process. Topology optimization of a conventional tool geometry is conducted in order to identify minimum material required within the tool. The results obtained from digital twin prototyping and topology optimization envisioned the development of a hybrid tool. A hybrid tool consists of two different materials i.e., polymers and metals. The materials of a hybrid tool are selected from Ashby material charts on the basis of requirements resulting from process parameterization and topology optimization. A model of the hybrid tool is developed according to material properties of selected materials and identified tool design factors. The model is imported in digital twin of RDB process and tool performance is investigated by conducting process simulations with different tube diameters. After obtaining process feasibility through digital twin, the hybrid tool consisting of polymer - PLA and metal - stainless steel is practically 3D printed and experimentally tested in an actual RDB process. The experimental results demonstrates that a 3D printed hybrid tool is capable of conducting bending operations with different tube diameters while enabling significant material saving within the tool. A comparison is made between the novel 3D printed hybrid tools and conventional steel tools. A design formula is presented that determines the efficiency of bending tools through Tool Efficiency index (TEi). For practical applications, the geometry of 3D printed hybrid tools is standardized through aspect ratio and corresponding upscale size factors.Source Type:Doctoral ThesisSeries:Forschungsberichte des Lehrstuhls für UmformtechnikVolume number:201 13 - Some of the metrics are blocked by yourconsent settings
Publication Design and Development of Hybrid Tools for Rotary Draw Bending Using Digital Twin and Additive Manufacturing Processes(2026-03-09)This research work presents the concept of using hybrid tools in production processes. A hybrid tool consisting of steel surfaces and 3D printed polymeric base structure is developed and successfully tested in Rotary Draw Bending process. The research work is conducted through tool and process performances obtained from Digital Twin of Rotary Draw Bending process. Hybrid tools are cost effective, lightweight and an adroit design strategy of hybrid tools possess the potential to enhance process flexibility.Source Type:DissertationSeries:Forschungsberichte des Lehrstuhls für Umformtechnik1 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Open Access , Methode zur Gestaltung segmentierter Werkzeuge für die Flexibilisierung von Biegeprozessen(2026)The megatrends of neo-ecology, connectivity, and individualization are fundamentally transforming manufacturing technology. From the perspective of sheet and profile forming processes, these megatrends generate the need for resource-efficient and highly flexible production methods. Common industrial bending processes with geometric-specific tools, such as rotary draw bending or compression bending, have limited flexibility because the final contour of the bent part is predetermined by the tool shape. Approaches to enhance flexibility include the segmentation of closed tool surfaces, allowing for adjustable tool contours. Previous investigations in this area have been limited to large sheet metal components or profile bending parts with large bending radii in the context of multi-point forming. This work presents a systematic methodology for designing segmented bending tools, using compression bending as the example process. This methodology focuses on investigating the cause-effect relationships between surface topology of the forming tools, the mechanical and geometric properties of the semi-finished product, and the resulting forming phenomena and mechanisms. Segmented tools affect nearly all geometric characteristics of the bent components. This is primarily due to a combination of cross-sectional ovalizations and free bending over the segment gaps, which superimpose base bending. Despite these unavoidable limiting forming mechanisms, high-quality parts can be produced through an appropriate process and tool setup. The developed design methodology provides a solid knowledge base and characteristic diagrams for determining gap dimensions, segment geometries, and process parameters. Furthermore, in-process adjustments to the segments demonstrate the tools' expanded range of applications. This enables for the targeted suppression of limiting forming mechanisms that are typically active in statically segmented tools. Looking ahead, such adaptive tools will require load-bearing structures that can withstand process forces and facilitate necessary segment movements. As a first step towards this aspect, the investigations conducted in this research work introduce a novel approach of topology optimization of forming tool structures based on the mathematical optimization of truss-like structures using mixed-integer programming.Source Type:Doctoral ThesisSeries:Forschungsberichte des Lehrstuhls für UmformtechnikVolume number:194 4 - Some of the metrics are blocked by yourconsent settings
Publication Methode zur Gestaltung segmentierter Werkzeuge für die Flexibilisierung von Biegeprozessen(2025-12-01)Die Megatrends der Neo-Ökologie, Konnektivität und Individualisierung transformieren die Fertigungstechnik grundlegend. Für Blech- und Profilumformverfahren resultiert hieraus unter anderem die Anforderung nach ressourceneffizienten und flexiblen Prozessen. Die industriell weit verbreiteten formgebundenen Biegeverfahren wie das Rotationszugbiegen oder das Abrollbiegen besitzen eine eingeschränkte Flexibilität, da die Endkontur des Bauteils durch die Werkzeuggeometrie vorgegeben ist. Ansätze zur Flexibilisierung bestehen in der Segmentierung der geschlossenen Werkzeugoberflächen, wodurch eine Einstellbarkeit der Werkzeugkontur ermöglicht wird. Die vorliegende Arbeit entwickelt eine Methode zur Gestaltung segmentierter Biegewerkzeuge. Die hierdurch generierten Freiheitsgrade erzeugen eine deutlich erhöhte Flexibilität hinsichtlich der mit einem einzigen Werkzeug herstellbaren Bauteilgeometrien – ein wichtiger Schritt in Richtung wandlungsfähiger Fertigungssysteme. Kern der Vorgehensweise ist die eingehende Erforschung der Wirkzusammenhänge zwischen der Oberflächentopologie der Werkzeuge, den Eigenschaften der Profilhalbzeuge und den resultierenden Umformphänomenen und -mechanismen in systematisch aufeinander aufbauenden Teillastfällen.Source Type:DissertationSeries:Forschungsberichte des Lehrstuhls für Umformtechnik - Some of the metrics are blocked by yourconsent settings
Publication Access status: Open Access , Verfahrensentwicklung 3D-Schwenkbiegen(2025)With increasing individualization, mass production is evolving towards personalized manufacturing, which is characterized by smaller batch sizes and a greater variety of variants. This increases the need for flexible manufacturing technologies. 3D-swivel-bending is an innovative approach to the low-tool production of complex profile components, particularly due to its ability to realize non-linear and three-dimensional bending edges and free-form surfaces. The development of this process aims to create more efficient and flexible methods for the manufacturing of components with variable cross-sections and load-adapted components. An important aspect is the extension of the swivel-bending principle by additional degrees of freedom to enable the shaping of non-linear bending edges and free-form surfaces. The process is based on a modified process instruction in which the axis of rotation of the bending tool is shifted relative to the bending edge, and adapted tool geometries are developed. The forming mechanisms and effects of 3D-swivel-bending are analyzed in a process design in order to describe the properties of the manufactured parts and the process limits analytically. Various methods for characterizing the mechanical behavior are presented in the process modelling to derive a process window for 3D-swivel-bending. This enables precise characterization of the forming mechanisms. The process window shows the working field of 3D-swivel-bending and can be used to evaluate and design future geometries. A validation of the developed methods evaluates the applicability of 3D-swivel-bending in industrial contexts and demonstrates technological and economic advantages. It shows that 3D-swivel-bending is particularly suitable for small and medium batch sizes in the automotive and aerospace industries, as well as in the construction sector. The process extension focusses on improvements in flexibility and applicability. Hybrid bending kinematics and new technologies for tool production and bending sequence planning are being developed. In addition, a process generator for digital planning and optimization of the production process is introduced. Thanks to its flexibility and efficiency, 3D-swivel-bending offers an innovative solution for complex components. It is particularly suitable for small batch sizes in industrial sectors and combines technological and economic advantages.Source Type:Doctoral ThesisSeries:Forschungsberichte des Lehrstuhls für UmformtechnikVolume number:186 8 - Some of the metrics are blocked by yourconsent settings
Publication Verfahrensentwicklung 3D-Schwenkbiegen(2025-11-17)Die vorliegende Dissertation behandelt die Entwicklung des 3D-Schwenkbiegens, einem innovativen Verfahren zur werkzeugarmen Herstellung komplexer Profilbauteile mit nichtlinearen Biegekanten und Freiformflächen. Durch die Erweiterung des klassischen Schwenkbiegeprinzips um zusätzliche Freiheitsgrade werden neue Gestaltungs- und Anwendungsmöglichkeiten geschaffen. Analytische Modelle, FE-Simulationen und experimentelle Studien führen zur Definition eines Prozessfensters, das die Verfahrensgrenzen beschreibt. Die Validierung zeigt das technologische und wirtschaftliche Potenzial des Verfahrens insbesondere für kleine und mittlere Losgrößen in der Automobil-, Luftfahrt- und Bauindustrie.Source Type:DissertationSeries:Forschungsberichte des Lehrstuhls für Umformtechnik3 2
