@misc{ShapovalovOstKukeetal., author = {Shapovalov, Oleg and Ost, Lucas and Kuke, Felix and Doynov, Nikolay and Ambrosio, Marcello and Seidlitz, Holger and Michailov, Vesselin}, title = {Entwicklung und Analyse einer F{\"u}gestrategie f{\"u}r FKV/Metall-Mischverbindungen auf Basis der CMT-Pinschweißtechnik}, series = {Joining Plastics}, volume = {17}, journal = {Joining Plastics}, number = {1}, issn = {1864-3450}, pages = {28 -- 35}, abstract = {Dieser Beitrag stellt eine Entwicklung, Anpassung und Untersuchung der neuartigen Pinschweißtechnik zur Verbindung thermoplastischer Faserkunststoffverbunde mit metallischen F{\"u}gepartnern dar. Die untersuchte F{\"u}getechnik bietet, im Vergleich zu anderen Verfahren, neben einer einseitigen Zug{\"a}nglichkeit, ein hohes Leichtbaupotenzial. An Multimaterial-Einzelpinverbindungen wurden die CMT-Pinschweißbarkeit charakterisiert und unterschiedliche F{\"u}gestrategien erprobt und ausgewertet. Als Bewertungskriterien wurden das Schweißgut sowie der Faser- und Matrixerhalt in Abh{\"a}ngigkeit 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 F{\"u}gezone analysiert. Der F{\"u}geprozess wurde an Funktionsmustern und diese wiederum in 3-Punkt-Biegeversuchen validiert sowie mit dem Kleben verglichen.}, language = {de} } @misc{SeidlitzMichailovOstetal., author = {Seidlitz, Holger and Michailov, Vesselin and Ost, Lucas and Kuke, Felix and Ambrosio, Marcello and Shapovalov, Oleg and Doynov, Nikolay}, title = {Simulation of Composites' Heating}, series = {Kunststoffe international}, volume = {113}, journal = {Kunststoffe international}, number = {4}, issn = {1862-4243}, pages = {60 -- 64}, abstract = {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.}, language = {en} } @misc{SanthanakrishnanBalakrishnanSeidlitzAmbrosioetal., author = {Santhanakrishnan Balakrishnan, Venkateswaran and Seidlitz, Holger and Ambrosio, Marcello and Schuhmann, Tilo}, title = {Study on the Quality of Quasi-Isotropic Composite Laminates Containing a Circular Hole}, series = {Journal of Materials Science Research}, volume = {6}, journal = {Journal of Materials Science Research}, number = {4}, issn = {1927-0593}, doi = {10.5539/jmsr.v6n4p67}, pages = {67 -- 78}, abstract = {Composite structures used in modern engineering applications are often subjected to circular holes in order to join with metal components via riveting, bolting or pinning joints. These design based holes will interrupt the force flux in the direction of the fibers and create high stress concentrations near the notched area. Objective of the project is to understand the quality of the quasi-isotropic composite laminates ([45°, -45°, 0°, 90°]S) containing circular hole. To achieve this objective, a 3-phase portal milling machine and a 5kW continuous wave (cw) CO2 laser system were used to produce the circular holes in the composite laminates. The processing parameters for both the processes are varied to understand its influence. The quality of the circular hole produced by these methods are further investigated and compared in order to arrive at the optimum processing parameters for the given quasi-isotropic composite laminates. The hole qualities were evaluated by means of delamination factor caused by milling; cone angle, matrix evaporation for cw-CO2 laser system. For further comparisons, the optimal parameter combinations of both methods were selected for a tensile test according to the standard ASTM D5766-2002.}, language = {en} } @misc{ShapovalovSeidlitzOstetal., author = {Shapovalov, Oleg and Seidlitz, Holger and Ost, Lucas and Doynov, Nikolay and Kuke, Felix and Ambrosio, Marcello and Michailov, Vesselin}, title = {Substitution von metallischen Schubfeldern im Fahrzeugbau durch f{\"u}getechnische Integration von FKV-Schalen}, series = {DVS Congress 2022, Große Schweißtechnische Tagung, DVS Campus ; Kurzfassungen der Vortr{\"a}ge der Veranstaltung in Koblenz vom 19. bis 21. September 2022 ; (Langfassungen der Beitr{\"a}ge auf USB-Karte)}, journal = {DVS Congress 2022, Große Schweißtechnische Tagung, DVS Campus ; Kurzfassungen der Vortr{\"a}ge der Veranstaltung in Koblenz vom 19. bis 21. September 2022 ; (Langfassungen der Beitr{\"a}ge auf USB-Karte)}, publisher = {DVS Media GmbH}, address = {D{\"u}sseldorf}, isbn = {978-3-96144-189-1}, pages = {385 -- 393}, abstract = {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 St{\"a}hlen bietet, im Vergleich zu anderen Verfahren, neben einer einseitigen Zug{\"a}nglichkeit, 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 Vorw{\"a}rmen von Organoblechen mittels Infrarotstrahlung entwickelt. Die Eignung der CMT-Pin-Technologie wurde sowohl f{\"u}r das F{\"u}gen von karbon- als auch glasfaserverst{\"a}rktem PA6 betrachtet. Als Bewertungskriterien wurden das Schweißgut sowie der Faser- und Matrixerhalt in Abh{\"a}ngigkeit der Schweißparameter untersucht. Das entwickelte Verfahren wurde mit herk{\"o}mmlichen F{\"u}gemethoden bzgl. der in Kopf- und Scherzugversuchen ermittelten Festigkeiten verglichen. Zur Bestimmung der Best{\"a}ndigkeit der Verbindungen gegen unterschiedliche Witterungsbedingungen wurden Salzspr{\"u}hnebel- und Wechselkorrosionstests durchgef{\"u}hrt. Mit dem F{\"u}gen von Hutprofilen wurde die Anwendung der entwickelte CMT-Pin-Technik am Tunnel sowie den L{\"a}ngs- und Quertr{\"a}gern der Bodenstruktur eines Kraftfahrzeugs demonstriert.}, language = {de} } @misc{SeidlitzFritzscheKlosheketal., author = {Seidlitz, Holger and Fritzsche, Sebastian and Kloshek, Alexander and Ambrosio, Marcello}, title = {Advanced welding technology for highly stressable multi material designs with fiber-reinforced plastics and metals}, series = {Open Journal of Composite Materials}, volume = {7}, journal = {Open Journal of Composite Materials}, number = {3}, issn = {2164-5655}, doi = {10.4236/ojcm.2017.73010}, pages = {166 -- 177}, abstract = {Organic sheets made out of fiber-reinforced thermoplastics are able to make a crucial contribution to increase the lightweight potential of a design. They show high specific strength- and stiffness properties, good damping characteristics and recycling capabilities, while being able to show a higher energy absorption capacity than comparable metal constructions. Nowadays, multi-material designs are an established way in the automotive industry to combine the benefits of metal and fiber-reinforced plastics. Currently used technologies for the joining of organic sheets and metals in large-scale production are mechanical joining technologies and adhesive technologies. Both techniques require large overlapping areas that are not required in the design of the part. Additionally, mechanical joining is usually combined with "fiber-destroying" pre-drilling and punching processes. This will disturb the force flux at the joining location 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 joining of organic sheets and metals in a load path optimized way, with short cycle times. This is achieved by redirecting the fibers around the joining area by the insertion of a thin metal pin. The path of the fibers will be similar to paths of fibers inside structures found in nature, e.g. a knothole inside of a tree. As a result of the bionic fiber design of the joint, 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 shear-tests based on the DIN EN ISO 14273. Every specimen joined with the new CMT Pin joining technology showed a higher strength than specimens joined with one blind rivet. Specimens joined with two or three pin rows show a higher strength than specimens joined with two blind rivets.}, language = {en} } @misc{SeidlitzOstAmbrosioetal., author = {Seidlitz, Holger and Ost, Lucas and Ambrosio, Marcello and Kuke, Felix and Michailov, Vesselin and Shapovalov, Oleg and Doynov, Nikolay}, title = {Erw{\"a}rmung von Composites simulieren}, series = {Kunststoffe}, journal = {Kunststoffe}, number = {2}, issn = {0023-5563}, pages = {66 -- 70}, abstract = {Neuartige, werkstoffgerechte F{\"u}geverfahren f{\"u}r Faserkunststoffverbunde setzen die Erw{\"a}rmung der Materialien voraus. Um die damit verbundenen komplexen Temperaturfelder und -verl{\"a}ufe vorherzusagen, haben das Fraunhofer IAP und die BTU Cottbus-Senftenberg numerische Verfahren entwickelt. Mit diesen k{\"o}nnen auch verschiedene Strahlungsquellen und Prozessabl{\"a}ufe simuliert werden.}, language = {de} } @misc{HannanSeidlitzHartungetal., author = {Hannan, Azmin Nasrin and Seidlitz, Holger and Hartung, David and Kuke, Felix and Ambrosio, Marcello and M{\"u}ller, Marco}, title = {Sustainability and Circular Economy in Carbon Fiber-Reinforced Plastics}, series = {Materials Circular Economy}, volume = {6}, journal = {Materials Circular Economy}, number = {1}, publisher = {Springer Science and Business Media LLC}, issn = {2524-8146}, doi = {10.1007/s42824-024-00111-2}, pages = {11}, abstract = {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.}, language = {en} }