TY - CHAP A1 - Seidlitz, Holger A1 - Kuke, Felix A1 - Tsombanis, Nikolas T1 - Leichtbautechnologien und Mischbauweisen mit Faser-Kunststoff-Verbunden T2 - Innovationsforum des Regionalen Wachstumskerns Westlausitz, Cottbus, 2016 Y1 - 2016 UR - http://www2.fh-lausitz.de/fhl/iurs/downloads/Leichtbautechnologien_und_Mischbauweisen_mit_Faser-Kunststoff-Verbunden.pdf ER - TY - CHAP A1 - Doynov, Nikolay A1 - Kuke, Felix A1 - Michailov, Vesselin T1 - Thermal straightening simulation of welded structures T2 - Proceedings, METEC & 2nd ESTAD 2015, European Steel Technology and Application Days, Düsseldorf, Germany, CCD Congress Center Düsseldorf, 15 - 19 June 2015 Y1 - 2015 SN - 978-3-00-049542-7 SP - P 709, 1 EP - 6 PB - TEMA Technologie Marketing AG CY - Aachen ER - TY - CHAP A1 - Kuke, Felix A1 - Kloshek, Alexander A1 - Michailov, Vesselin T1 - Untersuchung des Einflusses von rohrförmigen Stahlelektroden auf das Prozessverhalten und den Werkstoffübergang beim MSG-Schweißen T2 - DVS Congress, September 2015, Nürnberg Y1 - 2015 SN - 978-3-945023-46-4 SP - 615 EP - 620 PB - DVS Media GmbH CY - Düsseldorf ER - TY - BOOK A1 - Michailov, Vesselin A1 - Doynov, Nikolay A1 - Kuke, Felix T1 - Anwendungsnahe Simulation des thermischen Richtens : Forschungsvorhaben P 1008/IGF-Nr. 17970 BR Y1 - 2016 SN - 978-3-946885-03-0 PB - Verlag und Vertriebsgesellschaft mbH CY - Düsseldorf ER - TY - CHAP A1 - Seidlitz, Holger A1 - Kuke, Felix A1 - Tsombanis, Nikolas T1 - Advanced joining technology for the production of highly stressable lightweight structures, with fiber-reinforced plastics and metal T2 - 3rd International MERGE Technologies Conference (IMTC), Chemnitz, 2017 N2 - Organic sheets made of fiber-reinforced thermoplastics can make a crucial contribution to increase the lightweight potential of a technical design. They show high specific strength- and stiffness properties as well as good damping characteristics, while being able to show a higher energy absorption capacity than comparable metal constructions. In addition, organic sheets provide good recycling capabilities. Nowadays, multi-material designs are an established way in the automotive industry to combine the benefits of metal and fiber-reinforced plastics (FRP). Currently used technologies for the joining of organic sheets and metals in large-scale production are mechanical joining and adhesive technologies. Both require large overlapping areas to achieve the desired joint strength and stiffness of the technical design. Additionally, mechanical joining is usually combined with “fiber-destroying” pre-drilling and punching processes. This will disturb the force flux at the joint zone by causing unwanted fiber- and inter-fiber failure and inducing critical notch stresses. Therefore, the multi-material design with fiber-reinforced thermoplastics and metals needs optimized joining techniques that don’t interrupt the force flux, so that higher loads can be induced and the full benefit of the FRP material can be used. This article focuses on the characterization of a new joining technology, based on the Cold Metal Transfer (CMT) welding process, that allows to join organic sheets and metals in a load path optimized design. This is achieved by realigning the fibers around the joint zone by the integration of a thin metal pin. The alignment of the fibers will be similar to load paths of fibers inside structures found in nature. A tree with a knothole is always going to align its fibers in principle stress direction. As a result of the bionic fiber design, high joining strengths can be achieved. The increase of the joint strength compared to blind riveting was performed and proven with stainless steel and orthotropic reinforced composites in tensile shear-tests, based on the DIN EN ISO 14273. KW - Automotive KW - CMT-Welding KW - Composite KW - Joining KW - Metal Y1 - 2018 U6 - https://doi.org/10.21935/tls.v1i2.76 VL - 1 IS - 2 SP - 54 EP - 67 ER - TY - GEN A1 - Yellur, Manoja Rao A1 - Seidlitz, Holger A1 - Kuke, Felix A1 - Wartig, Kevin A1 - Tsombanis, Nikolas T1 - A low velocity impact study on press formed thermoplastic honeycomb sandwich panels T2 - Composite Structures N2 - At present plywood structures are used in the loading area of utility structures. Low velocity impact studies on these structures showed cracks on its lower surface. Hence, in the current study low-velocity impact of a lighter honeycomb sandwich structure is investigated to satisfy the needs of the utility vehicle segment. To meet this objective, facing sheets are manufactured using the polypropylene matrix and glass fibers. Polypropylene honeycombs are used in the study. Depending on the experimental boundary conditions, a cross-ply laminate set up is used for the facing sheets. An impact energy of 100 J is chosen in the study. This energy caused visible failure on the plywood sample. Hence a lighter sandwich construction which can resist 100 J impact is implemented in this study. Influence of top and bottom facing sheet thicknesses on the amount of damage inflicted on its surfaces are studied. Experimental histories of absorbed energy and contact force are recorded. A finite element analysis is performed using LS-DYNA and numerical results are compared with the experimental responses. A honeycomb sandwich panel [0/90/90/0/Core/0/90/90/0] meeting the objective of the study is seen as an optimum replacement for the existing plywood structures. KW - Low-velocity impact KW - Sandwich panel KW - Honeycomb core KW - Finite element analysis (FEA) Y1 - 2019 UR - http://www.sciencedirect.com/science/article/pii/S0263822318334743 U6 - https://doi.org/10.1016/j.compstruct.2019.111061 SN - 0263-8223 VL - 225 SP - 111061 ER - TY - GEN A1 - Santhanakrishnan Balakrishnan, Venkateswaran A1 - Obrosov, Aleksei A1 - Kuke, Felix A1 - Seidlitz, Holger A1 - Weiß, Sabine T1 - Influence of metal surface preparation on the flexural strength and impact damage behaviour of thermoplastic FRP reinforced metal laminate made by press forming T2 - Composites Part B: Engineering N2 - In this paper the relationship between surface energy and flexural strength of metal laminate made by reinforcing glass fibre reinforced polymer on steel surfaces was investigated. Sand blasting was performed on 22MnB5 steel surface. This steel was stacked together with layers of unidirectional glass/polyamide-6 prepreg, followed by pressing in a hot press. Influenced parameters are pressure, temperature and time. 3D profilometer analysis was used to investigate the roughness profile on the surface of the steel generated by the sand blasting. The surface energy of the steel surface was calculated from a set of contact angles measured by three different liquids. To identify the optimal surface treatment, the variation of surface energy, flexural strength and roughness of the steel surface was determined as function of the surface treatment. Surface roughness (Ra of 1.08 μm), results indicate that increasing surface roughness leads to improvement in flexural modulus. The increase further leads to decrease in flexural modulus. In addition, the influence of surface energy and flexural strength on the impact damage behaviour was investigated too. The results showed that the sample with highest flexural modulus had the lowest impact-induced damage area. KW - Fiber reinforced plastic (FRP) KW - FRP reinforced metal composite KW - Sand blasting surface treatment KW - Surface energy KW - Contact angle Y1 - 2019 UR - https://www.sciencedirect.com/science/article/pii/S135983681930318X U6 - https://doi.org/10.1016/j.compositesb.2019.05.094 SN - 1359-8368 VL - 173 ER - TY - GEN A1 - Shapovalov, Oleg A1 - Seidlitz, Holger A1 - Ost, Lucas A1 - Doynov, Nikolay A1 - Kuke, Felix A1 - Ambrosio, Marcello A1 - Michailov, Vesselin T1 - Substitution von metallischen Schubfeldern im Fahrzeugbau durch fügetechnische Integration von FKV-Schalen T2 - DVS Congress 2022, Große Schweißtechnische Tagung, DVS Campus ; Kurzfassungen der Vorträge der Veranstaltung in Koblenz vom 19. bis 21. September 2022 ; (Langfassungen der Beiträge auf USB-Karte) N2 - Durch den strukturellen Einsatz von Faser-Kunststoff-Verbunden (FKV) lassen sich hochwertige gewichtsoptimierte Karosserien in Mischbauweise umsetzen. Die untersuchte CMT-Pin-Schweißtechnik zur Verbindung von thermoplastischen Organoblechen mit Stählen bietet, im Vergleich zu anderen Verfahren, neben einer einseitigen Zugänglichkeit, ein hohes Leichtbaupotenzial. Das Vorhaben wurde auf eine werkstoff-, prozess- und konstruktionsgerechte Umsetzung des Verfahrens ausgerichtet. Auf Basis experimenteller und numerischer Untersuchungen wurde eine Methode zum Vorwärmen von Organoblechen mittels Infrarotstrahlung entwickelt. Die Eignung der CMT-Pin-Technologie wurde sowohl für das Fügen von karbon- als auch glasfaserverstärktem PA6 betrachtet. Als Bewertungskriterien wurden das Schweißgut sowie der Faser- und Matrixerhalt in Abhängigkeit der Schweißparameter untersucht. Das entwickelte Verfahren wurde mit herkömmlichen Fügemethoden bzgl. der in Kopf- und Scherzugversuchen ermittelten Festigkeiten verglichen. Zur Bestimmung der Beständigkeit der Verbindungen gegen unterschiedliche Witterungsbedingungen wurden Salzsprühnebel- und Wechselkorrosionstests durchgeführt. Mit dem Fügen von Hutprofilen wurde die Anwendung der entwickelte CMT-Pin-Technik am Tunnel sowie den Längs- und Querträgern der Bodenstruktur eines Kraftfahrzeugs demonstriert. Y1 - 2022 UR - https://www.dvs-ev.de/call4papers/abstract.cfm?vid=115&pid=7586 SN - 978-3-96144-189-1 SP - 385 EP - 393 PB - DVS Media GmbH CY - Düsseldorf ER - TY - CHAP A1 - Seidlitz, Holger A1 - Ulke-Winter, Lars A1 - Kuke, Felix A1 - Ost, Lucas ED - Kumar, Sanjeev T1 - Material and Load Path Appropriate Joining Techniques for FRP/Metal Hybrid Structures T2 - Welding - Materials, Fabrication Processes, and Industry 5.0 N2 - Fiber-reinforced plastics (FRP) offer great lightweight construction potential. However, the anisotropic high-performance materials can only be fully utilized through the development of material-specific joining processes. A literature study shows that conventional methods such as screwing, riveting and bolting are unsuitable, since the load-bearing fibers are severed in the joining region. This leads to high-stress concentrations. To reduce these, a method is presented in which through holes are created in thermoplastic FRP by reorienting the fibers in this area around the point of disruption in accordance with the load path. For this purpose, the polymer matrix is softened locally by applying heat and penetrated with a needle or mandrel. Based on this, a technology for material-specific joining of FRP and metals has been developed in the form of thermomechanical flow drill joining. In this process, a mandrel forms a bush from the metal component and deflects the fibers of the locally softened organic sheet to suit the material. Cold metal transfer (CMT) pin welding is presented as another fully automatable joining process. In this method, the softened plastic component is penetrated with the welding wire, displacing the fibers in the joining area and realigning them to suit the load path. KW - fiber-reinforced plastics KW - thermomechanical flow drill joining KW - cold metal transfer pin welding KW - load path KW - fiber orientation Y1 - 2023 UR - https://www.intechopen.com/books/1002588 SN - 978-1-83769-870-7 SN - 978-1-83769-872-1 U6 - https://doi.org/10.5772/intechopen.1002239 PB - IntechOpen CY - London ET - 1. Auflage ER - TY - GEN A1 - Hannan, Azmin Nasrin A1 - Seidlitz, Holger A1 - Hartung, David A1 - Kuke, Felix A1 - Ambrosio, Marcello A1 - Müller, Marco T1 - Sustainability and Circular Economy in Carbon Fiber-Reinforced Plastics T2 - Materials Circular Economy N2 - Carbon fiber-reinforced plastic (CFRP) components are known for their exceptional resilience and ultra-lightweight nature, making them the preferred choice for applications requiring high mechanical loads with minimal weight. However, the intricate and anisotropic structure of CFRP components poses challenges, resulting in expensive repairs and testing. This complexity also leads to increased waste generation. Yet, innovative recycling processes offer a solution by reintegrating carbon components into a closed material cycle, promoting sustainability and circular economy principles. This work focuses on recycled CFs (rCFs) obtained through a continuous recycling method for CFRP primary recyclate from composite pressure vessel. Furthermore, re-purposing of the separated matrix material for secondary energy sources makes the process, a 100% recycling route. This closed-loop approach addresses conventional pyrolysis challenges and contributes to more efficient utilization of CFRP waste components. rCF and recycled polyethylene terephthalate (rPET) polymers were compounded through an extrusion process. Test specimens were then fabricated according to standard test norms to evaluate the resulting tensile and bending properties. The tensile and flexural modulus of the rCF-rPET obtained are 6.80 and 4.99 GPa, respectively. The need for enhancing the quality of rCF is apparent. Suggestive and potential implications and the marketability of rCF-rPET compounds are also discussed. KW - Sustainability KW - Circular Economy KW - Carbon Fiber-Reinforced Plastics Y1 - 2024 U6 - https://doi.org/10.1007/s42824-024-00111-2 SN - 2524-8146 VL - 6 IS - 1 PB - Springer Science and Business Media LLC ER - TY - GEN A1 - Rüppel, Gernot Wilhelm A1 - Dorn, Oliver Niklas A1 - Kuke, Felix A1 - Ulke-Winter, Lars A1 - Seidlitz, Holger T1 - Optical tape detection using an IR camera to create a digital twin of rotationally symmetrical wet-wound FRP components T2 - Journal of Engineering 360 N2 - Wet-winding is used to manufacture rotationally symmetrical components such as pipes and pressure vessels, as well as non-rotationally symmetrical components like T-connectors. During this process, a resin-impregnated fiber (e.g., glass or carbon fiber) is wound around a core. The winding pattern influences the mechanical properties, including stiffness and strength of the component, and is optimized based on the expected loads. In practice, however, factors such as tape tension and resin content can cause deviations from the predefined winding pattern. This paper proposes a measuring system utilizing an IR-camera to record the winding pattern during production. The collected data is processed and converted into a digital twin for further analysis. KW - digital twin KW - wet winding KW - IR-Camera KW - optical fiber detection KW - optical tape detection Y1 - 2024 U6 - https://doi.org/10.5604/01.3001.0054.8851 SN - 3071-7507 VL - 1 (2024) IS - 1/24 SP - 46 EP - 57 PB - Index Copernicus ER - TY - GEN A1 - Ost, Lucas A1 - Seidlitz, Holger A1 - Ulke-Winter, Lars A1 - Kuke, Felix T1 - Development of a spherical high‐pressure tank for hydrogen storage in mobile and stationary applications T2 - Energy Technology N2 - In the sub‐project Mukran of the BMBF‐funded flagship project TransHyDE, spherical and nearly spherical‐shaped (isotensoids with short cylindrical spacer) high‐pressure tanks are developed for hydrogen storage. This article presents the planned work of the Chair of Polymer‐based Lightweight Design at the BTU Cottbus–Senftenberg and the research division PYCO at the Fraunhofer IAP. The research topics include the fiber‐compatible design of the liners, the rule‐based optimization of the layer structure of the load‐bearing overwrap made of carbon fiber‐reinforced plastic, the development of a fiber placement strategy, and the integration of the tanks into a frame as a mobile storage solution. KW - CFRP pressure vessel KW - hydrogen KW - pressure vessel KW - spherical pressure vessel Y1 - 2024 U6 - https://doi.org/10.1002/ente.202300942 SN - 2194-4288 PB - Wiley ER - TY - GEN A1 - Seidlitz, Holger A1 - Ost, Lucas A1 - Ambrosio, Marcello A1 - Kuke, Felix A1 - Michailov, Vesselin A1 - Shapovalov, Oleg A1 - Doynov, Nikolay T1 - Erwärmung von Composites simulieren T2 - Kunststoffe N2 - Neuartige, werkstoffgerechte Fügeverfahren für Faserkunststoffverbunde setzen die Erwärmung der Materialien voraus. Um die damit verbundenen komplexen Temperaturfelder und -verläufe vorherzusagen, haben das Fraunhofer IAP und die BTU Cottbus-Senftenberg numerische Verfahren entwickelt. Mit diesen können auch verschiedene Strahlungsquellen und Prozessabläufe simuliert werden. KW - Faserkunststoffverbunde KW - Fügen KW - Simulation Y1 - 2023 UR - https://www.kunststoffe.de/a/article-3363044 SN - 0023-5563 IS - 2 SP - 66 EP - 70 ER - TY - GEN A1 - Shapovalov, Oleg A1 - Ost, Lucas A1 - Kuke, Felix A1 - Doynov, Nikolay A1 - Ambrosio, Marcello A1 - Seidlitz, Holger A1 - Michailov, Vesselin T1 - Entwicklung und Analyse einer Fügestrategie für FKV/Metall-Mischverbindungen auf Basis der CMT-Pinschweißtechnik T2 - Joining Plastics N2 - Dieser Beitrag stellt eine Entwicklung, Anpassung und Untersuchung der neuartigen Pinschweißtechnik zur Verbindung thermoplastischer Faserkunststoffverbunde mit metallischen Fügepartnern dar. Die untersuchte Fügetechnik bietet, im Vergleich zu anderen Verfahren, neben einer einseitigen Zugänglichkeit, ein hohes Leichtbaupotenzial. An Multimaterial-Einzelpinverbindungen wurden die CMT-Pinschweißbarkeit charakterisiert und unterschiedliche Fügestrategien erprobt und ausgewertet. Als Bewertungskriterien wurden das Schweißgut sowie der Faser- und Matrixerhalt in Abhängigkeit von den Schweißparametern untersucht. Die mechanische Beanspruchbarkeit der mit dem entwickelten Verfahren erstellten Verbindungen wurde in Scherzugversuchen ermittelt. An Mehrpinverbindungen wurde anschließend der Einfluss der Pinanordnung untersucht und die Auslegung der Fügezone analysiert. Der Fügeprozess wurde an Funktionsmustern und diese wiederum in 3-Punkt-Biegeversuchen validiert sowie mit dem Kleben verglichen. Y1 - 2023 UR - https://www.joining-plastics.info/artikel/entwicklung-und-analyse-einer-fuegestrategie-fuer-fkvmetall-mischverbindungen-auf-basis-der-cmt-pinschweisstechnik SN - 1864-3450 VL - 17 IS - 1 SP - 28 EP - 35 ER - TY - GEN A1 - Seidlitz, Holger A1 - Michailov, Vesselin A1 - Ost, Lucas A1 - Kuke, Felix A1 - Ambrosio, Marcello A1 - Shapovalov, Oleg A1 - Doynov, Nikolay T1 - Simulation of Composites’ Heating T2 - Kunststoffe international N2 - Modern material-compatible joining methods for fiber-reinforced plastics require the heating of the materials. In order to predict the respective complex temperature fields and curves, the Fraunhofer IAP and the BTU Cottbus-Senftenberg have developed numerical methods, which are able to simulate different radiation sources and process sequences as well. KW - Composites KW - Simulation KW - Joining of Fiber-Reinforced Plastic Composites Y1 - 2023 UR - https://epaper.kunststoffe.de/en/read/26/26/2023-05-26/1 SN - 1862-4243 VL - 113 IS - 4 SP - 60 EP - 64 ER - TY - GEN A1 - Kepir, Yusuf A1 - Seidlitz, Holger A1 - Ulke-Winter, Lars A1 - Felix, Kuke T1 - Lightweight heat exchanger design using graphene-reinforced ceramics : a comparative study of dimensional and material effects T2 - Proceedings of the 4th International Online Conference on Materials, 3–6 November 2025 N2 - In high-temperature environments, heat exchangers require lightweight designs, high thermal resistance, and high effectiveness. Graphene-reinforced ceramic matrix composites (G-CMC) offer promising thermal properties for such applications. This study investigates the effectiveness changes of a block-type heat exchanger made of G-CMC, depending on the length and design, leveraging the potential of 3D printing in the production of complex geometries. KW - Ceramic matrix composite KW - Heat exchanger KW - Numerical analysis KW - Heat transfer KW - Thermal effectiveness Y1 - 2025 UR - https://sciforum.net/paper/view/25988 PB - MDPI CY - Basel ER - TY - GEN A1 - Kepir, Yusuf A1 - Seidlitz, Holger A1 - Ulke-Winter, Lars A1 - Kuke, Felix T1 - Geometric optimization and advanced material integration for enhanced thermal performance of compact cross-flow heat exchangers in high-temperature applications T2 - Proceedings of the 6th International Electronic Conference on Applied Sciences, 9–11 December 2025 N2 - Heat exchangers used in high-temperature environments require lightweight designs with high thermal resistance and efficiency. This study numerically investigates the thermal performance of a multi-channel compact cross-flow heat exchanger, focusing on geometric configurations and material selection. KW - Compact heat exchanger KW - Geometric optimization KW - Thermal performance KW - Turbulence promoters KW - Lightweight design Y1 - 2025 UR - https://sciforum.net/paper/view/27631 PB - MDPI CY - Basel ER -