TY - GEN A1 - Kroll, Lothar A1 - Czech, Adam A1 - Seidlitz, Holger A1 - Ulke-Winter, Lars A1 - Müller, Sascha ED - Wielage, Bernhard T1 - Mechanisches Verhalten von CFK-Scheiben mit variabelaxialem Faserverlauf auf Basis der Tailored-Fibre-Placement-Technologie unter Bolzenbelastung T2 - Tagungsband zum 18. Symposium Verbundwerkstoffe und Werkstoffverbunde, Chemnitz, 30.03. bis 01.04.2011 Y1 - 2011 SN - 978-3-00-033801-4 SP - 585 EP - 590 PB - IWW CY - Chemnitz ER - TY - GEN A1 - Ulke-Winter, Lars A1 - Kroll, Lothar A1 - Seidlitz, Holger T1 - Discrete optimization of laminate stacking sequence according to failure criteria T2 - Recent Developments in Artificial Intelligence Methods, AI-METH 2009 Y1 - 2009 SN - 83-60759-15-4 SP - 57 EP - 58 PB - Silesian University of Technology CY - Gliwice ER - TY - GEN A1 - Seidlitz, Holger A1 - Kroll, Lothar A1 - Ulke-Winter, Lars ED - Gehde, Michael ED - Wagenknecht, Udo ED - Bloß, Peter T1 - Faserverbundgerechte Krafteinleitungssysteme für Hochleistungskomponenten in Mischbauweise T2 - Technomer 2009, 21. Fachtagung über Verarbeitung und Anwendung von Polymeren, Chemnitz, 2009, Plenum, Vorträge, Posterbeiträge, Kurzfassungen Y1 - 2009 SN - 978-3-939382-09-6 SP - S. 55 PB - Institut für Allgemeinen Maschinenbau und Kunststofftechnik, Techn. Univ. [u.a.] CY - Chemnitz ER - TY - GEN A1 - Seidlitz, Holger A1 - Kroll, Lothar A1 - Ulke-Winter, Lars A1 - Schumann, Tilo ED - Meynerts, Peter T1 - Krafteinleitungssysteme bei hybriden Hochleistungskomponenten T2 - Innovation mit textilen Strukturen, 12. Chemnitzer Textiltechnik-Tagung, 30. September und 1. Oktober 2009 Y1 - 2009 SN - 978-3-9812554-3-0 SP - 220 EP - 230 PB - Institut für Allgemeinen Maschinenbau und Kunststofftechnik [u.a.] CY - Chemnitz ER - TY - GEN A1 - Seidlitz, Holger A1 - Kroll, Lothar A1 - Ulke-Winter, Lars T1 - Kraftflussgerechte Verbindungstechniken für Hochleistungskomponenten in Mischbauweise T2 - Leichtbau-Kongress, Salzburg, 23. - 25. Juni 2009, EuroLITE, Internationale Fachmesse für Leichtbaukonstruktion Y1 - 2009 PB - Hochschule CY - Landshut ER - TY - GEN A1 - Seidlitz, Holger A1 - Kroll, Lothar A1 - Ulke-Winter, Lars T1 - Load adjusted joining technology for Composite-Metal Hybrids T2 - Recent Developments in Artificial Intelligence Methods, AI-METH 2009 Y1 - 2009 SN - 83-60759-15-4 U6 - https://doi.org/10.1155/2014/958501 SP - 51 EP - 52 PB - Silesian University of Technology CY - Gliwice ER - TY - CHAP A1 - Schleuß, Leander A1 - Seidlitz, Holger A1 - Fritzsche, Sebastian A1 - Schulze, Marcus A1 - Michailov, Vesselin A1 - Schuhmann, Tilo T1 - Gewichtsreduzierte Multi-Material-Bauweisen mit Organoblechen T2 - Tagungsband, 15. Chemnitzer Textiltechnik-Tagung, Chemnitz, Germany, 31.05-01.06.2016 Y1 - 2016 SN - 978-3-945479-06-3 SP - 112 EP - 119 PB - Technische Universität Chemnitz, Professur Fördertechnik CY - Chemnitz ER - TY - GEN A1 - Böttger, Philipp A1 - Meyer, Marcel A1 - Martin, Jörg A1 - Otto, Thomas Walter A1 - Geßner, Thomas A1 - Seidlitz, Holger A1 - Kroll, Lothar ED - Geßner, Thomas T1 - Integrateable light sources based on semiconductor nanocrystal T2 - Smart Systems Integration 2014, Aachen, 2014 Y1 - 2014 SN - 978-3-86359-201-1 SP - 451 EP - 454 PB - Apprimus Verlag CY - Aachen ER - TY - CHAP A1 - Haase, Florian Vincent A1 - Reinhold, Maximilian A1 - Woll, Ralf A1 - Wolf, Matthias A1 - Seidlitz, Holger ED - Walls, Lesley ED - Revie, Matthew ED - Bedford, Tim T1 - Reliability capability assessment of cooperative networks using the example of developing demonstrators of structured materials T2 - Risk, Reliability and Safety: Innovating Theory and Practice, Proceedings of the ESREL 2016, Glasgow (United Kingdom) Y1 - 2016 SN - 978-1-138-02997-2 SP - 1323 EP - 1329 PB - CRC Press CY - Boca Raton ER - TY - CHAP A1 - Seidlitz, Holger A1 - Bambach, Markus A1 - Fritzsche, Sebastian A1 - Gerstenberger, Colin T1 - High load‐bearing multi‐material‐joints for metal sheets and composites by incremental in‐situ forming processes T2 - ESAFORM 2016, proceedings of the 19th International ESAFORM Conference on Material Forming, conference date: 27-29 April 2016, Nantes, France Y1 - 2016 SN - 978-0-7354-1427-3 U6 - https://doi.org/10.1063/1.4963464 PB - AIP Publishing CY - Melville, NY ER - TY - CHAP A1 - Maqbool, Fawad A1 - Elze, Lars A1 - Seidlitz, Holger A1 - Bambach, Markus T1 - Comparison of Manufacturing of Lightweight Corrugated Sheet Sandwiches by Hydroforming and Incremental Sheet Forming T2 - ESAFORM 2016, proceedings of the 19th International ESAFORM Conference on Material Forming, conference date: 27-29 April 2016, Nantes, France Y1 - 2016 SN - 978-0-7354-1427-3 U6 - https://doi.org/10.1063/1.4963456 PB - AIP Publishing CY - Melville, NY ER - 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 - Seidlitz, Holger A1 - Fritzsche, Sebastian A1 - Schleuß, Leander A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Neuartige Fügetechnologie zum Herstellen von hochbelastbaren Multi-Material-Bauweisen aus textilverstärkten Kunststoffen und Metallen bei einseitiger Zugänglichkeit der Fügestelle T2 - DVS Congress 2016, Große Schweißtechnische Tagung, Vorträge der Veranstaltungen in Leipzig am 19. und 20. September 2016 Y1 - 2016 SN - 978-3-945023-74-7 SP - 424 EP - 428 PB - DVS-Verlag CY - Düsseldorf ER - TY - CHAP A1 - Fritzsche, Sebastian A1 - Seidlitz, Holger A1 - Winkelmann, Kai A1 - Michailov, Vesselin ED - Pająk, Anna T1 - Structural reinforced FRP sandwich constructions for lightweight floor panels T2 - Conference papers, APT '15, 11th International Conference Advances in Plastics Technology, Sosnowiec, 13 - 15 October 2015 Y1 - 2015 SN - 978-83-63555-47-4 CY - Gliwice ER - TY - CHAP A1 - Gerstenberger, Colin A1 - Seidlitz, Holger A1 - Osiecki, Tomasz A1 - Kroll, Lothar T1 - Bionic Inspired High Stressable Joints for Multi-material Constructions with FRP and Metals T2 - Materials Science Engineering (MSE 2014), Darmstadt, 2014 Y1 - 2014 UR - https://www-docs.b-tu.de/fg-leichtbau/public/publikationen/01_Abstract%20MSE%202014%20Gerstenberger%20et%20al.pdf ER - TY - CHAP A1 - Schulze, Marcus A1 - Seidlitz, Holger A1 - König, Franziska A1 - Weiß, Sabine ED - Dobrzański, Leszek A. T1 - Nanoindentation measurements of PVD coated multilayer constructions T2 - Programme and proceedings of the 22nd Winter International Scintific Conference on Achivements in Mechanical and Materials Engineering (AMME'15), Gliwice - Zakopane (Poland), 2015 Y1 - 2015 SN - 978-83-63553-39-5 PB - Gliwice CY - International OCSCO World Press ER - TY - GEN A1 - Seidlitz, Holger A1 - Simon, Sylvio A1 - Elze, Lars A1 - Schulze, Marcus T1 - Herstellung von strukturierten Leichtbaukomponenten Y1 - 2015 N1 - 15. Schwarzheider Kunststoffkolloquium, 22. September 2015 ER - TY - GEN A1 - Seidlitz, Holger A1 - Elze, Lars A1 - Schulze, Marcus T1 - Eigenschaften strukturierter Leichtbaukomponenten Y1 - 2015 N1 - DVS Congress und DVS Expo in Nürnberg am 16. und 17. September 2015 ER - TY - CHAP A1 - Hackert, Alexander A1 - Gerstenberger, Colin A1 - Osiecki, Tomasz A1 - Seidlitz, Holger T1 - Hybrid sandwich composites with porous aluminum core and thermoplastic fiber-reinforced composite top layers T2 - Proceedings of the 23rd Annual International Conference on Composites/Nano Engineering (ICCE23), Chengdu (China), 2015 Y1 - 2015 UR - https://www-docs.b-tu.de/fg-leichtbau/public/publikationen/HSC-short-paper_Hackert_2015-05-12.pdf SP - 247 EP - 248 ER - TY - CHAP A1 - Osiecki, Tomasz A1 - Gerstenberger, Colin A1 - Hackert, Alexander A1 - Kroll, Lothar A1 - Seidlitz, Holger T1 - Thermoplastic fiber reinforced/metal-hybrid laminates for structural lightweight applications T2 - Proceedings of the 23rd Annual International Conference on Composites/Nano Engineering (ICCE23), Chengdu (China), 2015 Y1 - 2015 UR - https://www-docs.b-tu.de/fg-leichtbau/public/publikationen/HL-short-paper_Osiecki_2015-05-12.pdf SP - 595 EP - 596 ER - TY - CHAP A1 - Gerstenberger, Colin A1 - Hackert, Alexander A1 - Osiecki, Tomasz A1 - Kroll, Lothar A1 - Seidlitz, Holger T1 - Load adjusted fiber reinforced polymer/metal joints in cathodic dip paint conditions T2 - Proceedings of the 23rd Annual International Conference on Composites/Nano Engineering (ICCE23), Chengdu (China), 2015 Y1 - 2015 UR - https://www-docs.b-tu.de/fg-leichtbau/public/publikationen/FDJ-short-paper_Gerstenberger_2015-05-12.pdf SP - 227 EP - 228 ER - TY - GEN A1 - Seidlitz, Holger A1 - Fritzsche, Sebastian A1 - Kloshek, Alexander A1 - Ambrosio, Marcello T1 - Advanced welding technology for highly stressable multi material designs with fiber-reinforced plastics and metals T2 - Open Journal of Composite Materials N2 - 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. KW - Multi-Material Design KW - Fiber Reinforced Plastics KW - Lightweight Automotive Structures Y1 - 2017 UR - https://www.scirp.org/Journal/PaperInformation.aspx?PaperID=77822 U6 - https://doi.org/10.4236/ojcm.2017.73010 SN - 2164-5655 SN - 2164 -5612 VL - 7 IS - 3 SP - 166 EP - 177 ER - TY - GEN A1 - Santhanakrishnan Balakrishnan, Venkateswaran A1 - Seidlitz, Holger A1 - Ambrosio, Marcello A1 - Schuhmann, Tilo T1 - Study on the Quality of Quasi-Isotropic Composite Laminates Containing a Circular Hole T2 - Journal of Materials Science Research N2 - 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. KW - circular hole KW - composite KW - CO2 laser KW - drilling KW - fiber reinforced polymer KW - FRP KW - notch Y1 - 2017 U6 - https://doi.org/10.5539/jmsr.v6n4p67 SN - 1927-0593 SN - 1927-0585 VL - 6 IS - 4 SP - 67 EP - 78 ER - TY - GEN A1 - Santhanakrishnan Balakrishnan, Venkateswaran A1 - Seidlitz, Holger T1 - Potential repair techniques for automotive composites: A review T2 - Composites Part B: Engineering N2 - Composite materials have gained popularity in automotive industries due to its lightweight potential, good damping behaviour as well as high strength and stiffness properties. Based on the increase in usage of composites, there is a growing interest for a repair technique in the automotive industry. Along with these raise in demand there comes a need for an all-inclusive review article and the objective of this article is to address this need. Two repair techniques, namely scarfing repair and injection repair, have the potential to be used in automotive industry. This paper compiles the various research work done in this field of repairing along with various processing steps associated with it. Further this paper reviews the non-destructive technique that can be used for damage identification and repair assessment. KW - Automotive repair KW - scarf repair KW - injection repair KW - polymer-matrix composites Y1 - 2018 UR - https://www.sciencedirect.com/science/article/pii/S1359836817342063 U6 - https://doi.org/10.1016/j.compositesb.2018.03.016 SN - 1359-8368 IS - 145 SP - 28 EP - 38 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 - PAT A1 - Schleuß, Leander A1 - Seidlitz, Holger A1 - Michailov, Vesselin T1 - Neue Fügetechnologie für Mischverbindungen Y1 - 2017 UR - https://depatisnet.dpma.de/DepatisNet/depatisnet?action=pdf&docid=DE102015118058A1 N1 - Offenlegungsschrift ER - TY - GEN A1 - Santhanakrishnan Balakrishnan, Venkateswaran A1 - Seidlitz, Holger A1 - Wartig, Kevin A1 - Tsombanis, Nikolas T1 - Influence of processing parameters on the impact behaviour of glass/polyamide-6 composite T2 - Composites Part B: Engineering N2 - This study aims to investigate the low-velocity impact response and post-impact flexural behaviour of glass/polyamide-6 (G/PA-6) composite. G/PA-6 composites with a layup configuration of [02,902]s were prepared via press-forming technique. Composite samples were developed using four different processing conditions, by modifying compression pressure and heating temperature. Local variations of fiber volume and porosity fraction were noticed for samples developed in each processing conditions. On the investigated samples, damages were induced by using 35 joule of drop weight impact to investigate the impact resistance of samples with respect to different processing conditions. The damage behaviour and residual flexural strength was characterized using a micro-CT and three-point bending tests respectively. Furthermore, the influence of porosity fraction on the residual flexural strength were investigated. This paper will provide necessary fundamental knowledge for future selection of processing parameters in order to have enhanced impact performance. KW - A. Polymer-matrix composites (PMCs) KW - A. Thermoplastic resin KW - B. Impact behaviour KW - B. Porosity KW - B. Fracture KW - Press forming technology Y1 - 2019 UR - http://www.sciencedirect.com/science/article/pii/S1359836818318535 U6 - https://doi.org/10.1016/j.compositesb.2018.09.064 SN - 1359-8368 VL - 159 SP - 292 EP - 299 ER - TY - GEN A1 - Santhanakrishnan Balakrishnan, Venkateswaran A1 - Seidlitz, Holger A1 - Weiß, Sabine T1 - Layup Configuration Effect on Notch Residual Strength in Composite Laminates T2 - Materials N2 - The current trend shows an increasing demand for composites due to their high stiffness to weight ratio and the recent progress in manufacturing and cost reduction of composites. To combine high strength and stiffness in a cost-effective way, composites are often joined with steel or aluminum. However, joining of thermoset composite materials is challenging because circular holes are often used to join them with their metal counterparts. These design based circular holes induce high stress concentration around the hole. The purpose of this paper is to focus on layup configuration and its impact on notch stress distribution. To ensure high quality and uniformity, the holes were machined by a 5 kW continuous wave (cw) CO2 laser. The stress distribution was evaluated and compared by using finite element analysis and Lekhnitskii’s equations. For further understanding, the notch strength of the laminates was compared and strain distributions were analyzed using the digital image correlation technique. KW - composite KW - notch stress KW - digital image correlation KW - ekhnitskii’s equation Y1 - 2018 U6 - https://doi.org/10.3390/ma11020308 SN - 1996-1944 VL - 11 IS - 2 ER - TY - CHAP A1 - Fritzsche, Sebastian A1 - Kloshek, Alexander A1 - Dietz, Eric A1 - Michailov, Vesselin A1 - Seidlitz, Holger A1 - Ossenbrink, Ralf T1 - SLM gefertigte Verbindungsknoten für Leichtbaurahmenelemente T2 - DVS Congress 2018 : Große Schweißtechnische Tagung, DVS-Studentenkongress, Vorträge der Veranstaltungen in Friedrichshafen am 17. und 18. September 2018 N2 - SLM gefertigte Verbindungsknoten für Leichtbaurahmenelemente KW - Selective Laser Melting KW - SLM KW - Leichtbau KW - 1.4404 KW - Topologieoptimierung KW - Schubfeld Y1 - 2018 SN - 978-3-96144-036-8 IS - 264 EP - 258 PB - DVS Media GmbH CY - Düsseldorf 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 - Santhanakrishnan Balakrishnan, Venkateswaran A1 - Hart-Rawung, Thawin A1 - Buhl, Johannes A1 - Seidlitz, Holger A1 - Bambach, Markus T1 - Impact and damage behaviour of FRP-metal hybrid laminates made by the reinforcement of glass fibers on 22MnB5 metal surface T2 - Composites Science and Technology Y1 - 2020 U6 - https://doi.org/10.1016/j.compscitech.2019.107949 SN - 1879-1050 SN - 0266-3538 VL - Vol. 187 ER - TY - GEN A1 - Rösch, Janina J. A1 - Seidlitz, Holger A1 - Pfeifer, Robin A1 - Burlefinger, Hubert A1 - Maurer, Thomas T1 - Preform joints in embroidered fabrics – influence on the mechanical properties T2 - Advanced Composite Materials N2 - Preforms with large complex geometry, for example, body parts for the automotive industry, are consisted into multiple elements – so-called sub-preforms. Hereby the sub-preforms can be adjusted to different local load cases but joining of these sub-preforms also raises challenges. The preform joints are decisive to the mechanical properties of the final component. The state-of-the-art joint, a single lap, results in a variation of wall thickness with local redirection of fibre orientation. In this paper, the influence of alternative joints of embroidered fabrics is analysed regarding the resulting mechanical properties of the part. The built test specimen contains different preform joints with different process-relevant parameters. Such as gaps between the sub-preforms, to analyse the influence on the mechanical performance. To reveal the various defects like voids, air pockets and to validate the fibre orientation, computer tomography (CT) investigation was performed on the built plates. In addition, the influence in mechanical properties was also analysed. The overlapping is analysed with tensile strength test according to DIN EN ISO 527-4. Y1 - 2020 UR - https://www.tandfonline.com/doi/abs/10.1080/09243046.2020.1744345 SP - 1 EP - 16 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 - GEN A1 - Hannan, Azmin Nasrin A1 - Seidlitz, Holger A1 - Müller, Marco A1 - Krenz, Jonas T1 - Investigations of technical challenges in compounding of recycled carbon fibers T2 - Zarzadzanie Przedsiebiorstwem. Enterprise Management N2 - Carbon fiber reinforced plastics (CFRP) owing to its excellent properties have found its extensive application in various fields ranging from medical to automobile and aerospace industries. This has thereby led to ever-increasing demand of carbon fiber production and as well as resulting in tonnes of carbon fiber wastes in the landfills [5]. Due to the high positive impacts of using carbon fibers, the energy intensive and cost intensive production of virgin fibers and the growing landfills are often overlooked. Hence, the need for recycling and repurposing of carbon fiber wastes have gained the significance at present day. Although various recycling technologies have been developed yet, various challenges are faced with processing of recycled carbon fibers (rCF). Besides, the desired application specific properties are not compromised for high cost and high-energy requirement. Therefore, an overall development of processing rCF is sought from not only a sustainability point but also an economic point. Various efficient recycling technologies are currently operating. The challenges arises in commercializing the recycled fibers after the recycling process. The recycled fibers often require various post-processing of fibers and undergoes fiber degradation. This induces a skeptical mindset for the buyers to introduce the recycled fibers in the material ecosystem. This paper currently discusses the processing challenges of long rCF in a compounding plant. To form a closed loop, the recycled fibers are obtained from the novel thermocatalytic degassing process from the CFRP recycling pioneers in Germany, Global EnerTec AG, Guben. This plant in Guben not only recycles carbon fibers from automotive CFRP wastes but also repurposes the epoxy matrices into secondary energy sources. This paper focuses in investigating the processing of rCF obtained from a 100% recycling technology. The aim is to investigate the possible technical challenges so that the rCF can be repurposed to new product manufacturing. Thereby, addressing the concerns with the development of closed loop circular economy in recycling CFRP wastes. KW - CFRP KW - rCF KW - recycling KW - circular economy KW - compounding KW - carbon fibers Y1 - 2023 UR - https://zp.ptzp.org.pl/ZPEM_26_2-2023.html U6 - https://doi.org/10.25961/ent.manag.26.01.03 SN - 1643-4773 VL - 26 IS - 2 SP - 7 EP - 12 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 - Erekath, Swathi A1 - Seidlitz, Holger A1 - Schreiner, Monika A1 - Dreyer, Christian T1 - Food for future: Exploring cutting-edge technology and practices in vertical farm T2 - Sustainable Cities and Society N2 - With the growing urbanized population, vertical farming becomes indispensable in eradicating hunger and ensuring food security for the future. Food security has become a major challenge for the future owing to the scarcity of land, rising global population, urbanization, and polluted soil and water resources. In this scenario, vertical farming as an innovative food production technology caters increased productivity with limited resources and improved carbon footprint. The review begins with a brief introduction to the concept of vertical farming, its opportunities and implications on the economy, environment, and society as a whole, following with an in-depth qualitative analysis of the cutting-edge innovations/technologies are presented in detail. Contrary to the numerous research focusing on mere analysis of economic viability and statistical analysis, the aim is to introduce real cutting-edge technologies that address the challenges of vertical farms such as lack of technical skills or energy requirements. The recent advances of vertical farms includes construction of outer vertical structure and growing shelves using light weight and transparent polymer composites, engineered and tunable LEDs lightings, 3-D printed and recyclable growing substrates, AI-integrated IoTs for environment control, harvesting materials for renewable energy storage etc. Such material innovations with inclusion of AI and robotics transform automated vertical farming into ‘state of the art’ agricultural technology. Production shelf fabricated using UV cured GBOV-glass fiber composite with 60% transparency can overcome the material weight limitation, corrosion, light obstructions etc. associated with the conventional steel shelves. Replacing non-renewable fossil fuels using renewable energy harvested by carbon dots, fluorescent materials, and perovskite solar cells is recommended to minimize the high capital investments associated with energy as well as to reduce the environmental impact. Smart materials such as phase change materials and thermoresponsive windows control the amount of energy expended whereas smart substrate promotes resource management. Application of the newest technology AI in vertical farming facilitates precise control of environment, early pest detection, automation of farming processes, data-driven decision making and precision agriculture. In short, vertical farms utilizing modern innovations of science and technology caters enhanced productivity, improved quality, reduced cost, resource management and sustainability. Hence, automated and sustainable vertical farms promoting global food security and circularity have the potential to transform into burgeoning technology of future. KW - Transportation KW - Renewable Energy, Sustainability and the Environment KW - Civil and Structural Engineering KW - Geography, Planning and Development Y1 - 2024 U6 - https://doi.org/10.1016/j.scs.2024.105357 SN - 2210-6707 VL - 106 ER - TY - GEN A1 - Recupido, Federica A1 - Lama, Giuseppe Cesare A1 - Steffen, Sebastian A1 - Dreyer, Christian A1 - Seidlitz, Holger A1 - Russo, Vincenzo A1 - Lavorgna, Marino A1 - De Luca Bossa, Ferdinando A1 - Silvano, Selena A1 - Boggioni, Laura A1 - Verdolotti, Letizia T1 - Efficient recycling pathway of bio-based composite polyurethane foams via sustainable diamine T2 - Ecotoxicology and Environmental Safety N2 - Aminolysis is widely recognized as a valuable chemical route for depolymerizing polymeric materials containing ester, amide, or urethane functional groups, including polyurethane foams. Bio-based polyurethane foams, pristine and reinforced with 40 wt% of sustainable fillers, were depolymerized in the presence of bio-derived butane-1,4-diamine, BDA. A process comparison was made using fossil-derived ethane-1,2-diamine, EDA, by varying amine/polyurethane ratio (F/A, 1:1 and 1:0.6). The obtained depolymerized systems were analyzed by FTIR and NMR characterizations to understand the effect of both diamines on the degradation pathway. The use of bio-based BDA seemed to be more effective with respect to conventional EDA, owing to its stronger basicity (and thus higher nucleophilicity), corresponding to faster depolymerization rates. BDA-based depolymerized systems were then employed to prepare second-generation bio-based composite polyurethane foams by partial replacement of isocyanate components (20 wt%). The morphological, mechanical, and thermal conductivity properties of the second-generation polyurethane foams were evaluated. The best performances (σ10 %=71 ± 9 kPa, λ = 0.042 ± 0.015 W∙ m-1 ∙K-1) were attained by employing the lowest F/A ratio (1:0.6); this demonstrates their potential application in different sectors such as packaging or construction, fulfilling the paradigm of the circular economy. KW - Health, Toxicology and Mutagenesis KW - Public Health, Environmental and Occupational Health KW - Pollution KW - General Medicine Y1 - 2024 U6 - https://doi.org/10.1016/j.ecoenv.2023.115758 SN - 0147-6513 VL - 269 ER - TY - GEN A1 - Błędzki, Andrzej A1 - Seidlitz, Holger A1 - Urbaniak, Magdalena A1 - Köhler, Mathias A1 - Adamcio, Andrzej A1 - Sobczyk, Marcin A1 - Demski, Szymon A1 - Boczkowska, Anna T1 - Reusing and recycling of composite wind turbine blades. A review of current practices and prospects. Part 1. Academic research T2 - Przemysł chemiczny N2 - A review, with 34 refs., of new materials for manufacturing the turbine blades, processes for monitoring maintenance and structural health of the blades as well as chem., thermal and mech. blade recycling technologies. KW - General Chemical Engineering KW - General Chemistry KW - polymer composites KW - wind turbine blades KW - global recycling projects KW - practical recovery and reuse KW - recycled carbon fibers Y1 - 2024 U6 - https://doi.org/10.15199/62.2024.2.2 SN - 0033-2496 VL - 103 IS - 2 SP - 225 EP - 233 ER - TY - GEN A1 - Błędzki, Andrzej A1 - Seidlitz, Holger A1 - Urbaniak, Magdalena A1 - Köhler, Mathias A1 - Adamcio, Andrzej A1 - Sobczyk, Marcin A1 - Demski, Szymon A1 - Boczkowska, Anna T1 - Reusing and recycling of composite wind turbine blades. A review of current practices and prospects. Part 2. Industrial activities T2 - Przemysł chemiczny N2 - A review, with 33 refs., of projects currently implemented and planned by large consortia in the area of recovering variety of composite materials for their reuse KW - General Chemical Engineering KW - General Chemistry KW - polymer composites KW - wind turbine blades KW - global recycling projects KW - practical recovery and reuse KW - recycled carbon fibers Y1 - 2024 U6 - https://doi.org/10.15199/62.2024.2.3 SN - 0033-2496 VL - 103 IS - 2 SP - 234 EP - 240 ER - TY - GEN A1 - Błędzki, Andrzej A1 - Seidlitz, Holger A1 - Urbaniak, Magdalena A1 - Köhler, Mathias A1 - Adamcio, Andrzej A1 - Sobczyk, Marcin A1 - Demski, Szymon A1 - Boczkowska, Anna T1 - Reusing and recycling of composite wind turbine blades. A review of current practices and prospects. Part 3. Various proposals offered by small and middle companies T2 - Przemysł chemiczny N2 - A review, with 32 refs., of various new proposals for recycling and reusing of wind turbine blades by small companies (including the Polish Anmet company). New projects on shredding blades as well as on architecture objects, road construction, geotechn. blocks, floating platforms and observation towers were presented. Prodn. of composite chipboard panels and recovery of carbon fibers by waste pyrolysis were also included. KW - General Chemical Engineering KW - General Chemistry KW - polymer composites KW - wind turbine blades KW - global recycling projects KW - practical recovery and reuse KW - recycled carbon fibers Y1 - 2024 U6 - https://doi.org/10.15199/62.2024.2.4 SN - 0033-2496 VL - 103 IS - 2 SP - 241 EP - 250 ER - TY - GEN A1 - Miah, Kamal Uddin Mohammad A1 - Kloshek, Alexander A1 - Ossenbrink, Ralf A1 - Seidlitz, Holger T1 - Selective Laser Melting of Pure Copper (Cu-ETP) T2 - 4th Symposium on Materials and Additive Manufacturing, Additive 2024, 22. - 24. Mai 2024, Book of Abstracts N2 - The main objective of this study is to address the difficulties related to the production of highly dense parts utilizing pure Cu-ETP powder. In order to achieve this goal, the SLM machine was modified by replacing the regular infrared laser with a laser operating in the range of 530 to 534 nm. Following this modification, a detailed experiment was conducted to determine the most effective procedural parameters for producing solid components and gyroid structures of Cu-ETP. The study determined thtat in order to produce a part density of 99.6 ± 0.2%, the following parameters are required: a laser power of 130 ± 10 W, a scanning speed of 350 mm/s, and a layer thickness of 25 µm. The microscopic analysis on the SLM-manufactured components showed a consistent grain structure across the build parts. Furthermore, it was discovered that exceeding the predetermined laser power and scanning speed parameters led to lower density of the parts. Conversely, decreasing the laser power and scanning speed below these thresholds was determined to be economically disadvantageous. Y1 - 2024 UR - https://acmit.at/wp-content/uploads/2024/08/Additive-2024_Book-of-abstracts.pdf SN - 978-3-88355-440-2 SP - 19 PB - Deutsche Gesellschaft für Materialkunde (DGM) e.V. CY - Bremen, Berlin ER - TY - GEN A1 - Kehm, Christian A1 - Wasilewski, Eric A1 - Miah, Kamal Uddin Mohammad A1 - Ossenbrink, Ralf A1 - Seidlitz, Holger T1 - Effects of extended shielding gas coverage on component contour accuracy in Wire Arc Additive Manufacturing T2 - 4th Symposium on Materials and Additive Manufacturing, Additive 2024, 22. - 24. Mai 2024, Book of Abstracts N2 - Producing near-net-shape components with Wire Arc Additive Manufacturing (WAAM) is a challenging task. Compared to laser-based additive manufacturing technologies, WAAM is characterized by a lower contour accuracy with higher surface roughness and more uneven surface profiles. Therefore, the WAAM requires a high degree of post-processing (machining) which reduces economic efficiency and increases material consumption. Therefore, topics such as process optimization with regard to the component contour are increasingly in the focus of research. This study presents the application of an extended shielding gas coverage in the WAAM process of steel to improve part contour accuracy. A specially adapted shielding gas coverage was manufactured with laser powder bed fusion and following used to study the influence on the resulting component contour and properties in comparison to standard shielding gas nozzles. The investigations include the analysis of temperature profiles, shape deviations, hardness and porosity in the component. In addition, process parameters such as gas flow rate and nozzle geometry were varied in order to evaluate their influence on the accuracy of the component contour. The extended shielding gas coverage reduces the average deviation from the target contour significantly by a degree of 49,44%. In addition, the maximum of the occurring deviation height could be decreased by 42,39%. The results show an improvement in the dimensional accuracy of the contour and the surface quality, resulting in higher reproducibility and less post-processing effort. Y1 - 2024 UR - https://acmit.at/wp-content/uploads/2024/08/Additive-2024_Book-of-abstracts.pdf SN - 978-3-88355-440-2 SP - 29 PB - Deutsche Gesellschaft für Materialkunde (DGM) e.V. CY - Bremen, Berlin ER - TY - GEN A1 - Nikitin, Alexander A1 - Turabov, Dashqin A1 - Ermilova, Evgeniia A1 - Evdokimov, Anton A1 - Ossenbrink, Ralf A1 - Seidlitz, Holger T1 - Using dynamic resistance to predict electrode surface degradation in resistance spot welding of 5182 aluminum alloy T2 - Welding in the World N2 - In this study, the correlation between dynamic resistance during the first 10 ms of welding time and the electrode surface condition in resistance spot welding of 5182 aluminum alloy has been investigated. The electrode surface rapidly degrades due to contamination and morphological changes, adversely affecting the weld spot surface. The accumulation of Cu-Al intermetallic phases on the electrode surface alters its roughness, leading to variations in dynamic resistance. By analyzing this correlation, optimal electrode milling intervals were identified to extend electrode life. This work focused on detecting crater formation on the electrode surface through dynamic resistance monitoring. The results indicate that resistance measurements provide a reliable approach for evaluating electrode wear, optimizing maintenance schedules, and reducing material removal during milling. KW - resistance spot welding KW - aluminum alloy KW - electrode wear KW - dynamic resistance KW - electrode surface Y1 - 2024 U6 - https://doi.org/10.1007/s40194-024-01872-9 VL - 69 SP - 449 EP - 458 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 - Sztorch, Bogna A1 - Romanczuk-Ruszuk, Eliza A1 - Głowacka, Julia A1 - Kustosz, Magdalena A1 - Osiecki, Tomasz A1 - Jakubowska, Paulina A1 - Seidlitz, Holger A1 - Przekop, Robert E. T1 - Improving the processing and mechanical properties of 3D printable biocomposite based on polylactide, sediment rock, and natural beeswax T2 - Polymer Bulletin N2 - Polylactide is a material often used in additive techniques. Due to poor mechanical properties, there is a constant search for additives, fillers, and modifiers that could improve these properties. Natural fillers and additives are promising compounds because they can improve the properties of the composite and at the same time are environmentally friendly. This work concerns the first-time modification of PLA using the Opoka sedimentary rock, modified with natural beeswax and commercially available wax. The addition of sedimentary rock caused the natural color of the obtained fibers, and it was found that the Opoka addition has a positive effect on the processing and printing parameters, allowing for a significant reduction in the operating temperature and the extrusion and printing speed, as well as better interlayer adhesion and adhesion to the printer bed, which is particularly important in the case of 3D printing. The obtained materials were characterized by a higher degree of crystallinity, and better mechanical and surface parameters (significantly higher contact angles and hydrophobic properties). KW - PLA KW - Sediment rock KW - Opoka KW - FDM KW - Waxes KW - 3D Printing Y1 - 2024 U6 - https://doi.org/10.1007/s00289-024-05614-1 SN - 0170-0839 VL - 2024 PB - Springer Science and Business Media LLC 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 - Hajhariri, Aliasghar A1 - Eberwein, Robert A1 - Perrone, Luca Pakj A1 - Cozzani, Valerio A1 - Otremba, Frank A1 - Seidlitz, Holger T1 - Study the impact of spacer at thermal degradation process of MLI-based insulation in fire condition T2 - Journal of Loss Prevention in the Process Industries N2 - To reduce CO2 emissions, energy carriers such as hydrogen are considered to be a solution. Consumption of hydrogen as a fuel meets several limitations such as its low volumetric energy density in gas phase. To tackle this problem, storage as well as transportation in liquified phase is recommended. To be able to handle this component in liquid phase, an efficient thermal insulation e.g., MLI insulation is required. Different studies have been addressed the vulnerability of such insulation against high thermal loads e.g., in an accident engaging fire. Some of research works have highlighted the importance of considering the MLI thermal degradation focusing on its reflective layer. However, limited number of studies addressed the thermal degradation of spacer material and its effect on the overall heat flux. In this study, through systematic experimental measurements, the effect of thermal loads on glass fleece, glass paper as well as polyester spacers are investigated. The results are reported in various temperature and heat flux profiles. Interpreting the temperature profiles revealed that, as the number of spacers in the medium increases, the peak temperature detectable by the temperature sensor on the measurement plate decreases. Each individual spacer contributes to mitigating the radiative energy received by the measurement plate. Stacks of 20–50 spacers (this is the number of layers in commercial MLI systems applied for liquid hydrogen applications) can potentially reduce the thermal radiation by 1–2 orders of magnitude. An empirical correlation to predict a heat flux attenuation factor is proposed, which is useful for further numerical and analytical studies in the temperature range from ambient to 300 °C. KW - Liquefied hydrogen KW - Liquefied natural gas KW - Cryogenic storage tank KW - Thermal insulation KW - Multi-Layer Insulation KW - Microspheres KW - Perlite Y1 - 2024 U6 - https://doi.org/10.1016/j.jlp.2024.105461 SN - 0950-4230 VL - 92 SP - 240 EP - 248 PB - Elsevier BV 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 -