@misc{SeidlitzKrollUlkeWinter, author = {Seidlitz, Holger and Kroll, Lothar and Ulke-Winter, Lars}, title = {Kraftflussgerechte Punktverbindungen - Hochbelastete Leichtbaustrukturen}, series = {Zeitschrift Kunststoffe}, volume = {101}, journal = {Zeitschrift Kunststoffe}, number = {3}, issn = {0023-5563}, pages = {50 -- 53}, language = {de} } @misc{KrollCzechSeidlitzetal., author = {Kroll, Lothar and Czech, Adam and Seidlitz, Holger and Ulke-Winter, Lars and M{\"u}ller, Sascha}, title = {Mechanisches Verhalten von CFK-Scheiben mit variabelaxialem Faserverlauf auf Basis der Tailored-Fibre-Placement-Technologie unter Bolzenbelastung}, series = {Tagungsband zum 18. Symposium Verbundwerkstoffe und Werkstoffverbunde, Chemnitz, 30.03. bis 01.04.2011}, journal = {Tagungsband zum 18. Symposium Verbundwerkstoffe und Werkstoffverbunde, Chemnitz, 30.03. bis 01.04.2011}, editor = {Wielage, Bernhard}, publisher = {IWW}, address = {Chemnitz}, isbn = {978-3-00-033801-4}, pages = {585 -- 590}, language = {de} } @misc{UlkeWinterKrollSeidlitz, author = {Ulke-Winter, Lars and Kroll, Lothar and Seidlitz, Holger}, title = {Discrete optimization of laminate stacking sequence according to failure criteria}, series = {Recent Developments in Artificial Intelligence Methods, AI-METH 2009}, journal = {Recent Developments in Artificial Intelligence Methods, AI-METH 2009}, publisher = {Silesian University of Technology}, address = {Gliwice}, isbn = {83-60759-15-4}, pages = {57 -- 58}, language = {en} } @misc{SeidlitzKrollUlkeWinter, author = {Seidlitz, Holger and Kroll, Lothar and Ulke-Winter, Lars}, title = {Faserverbundgerechte Krafteinleitungssysteme f{\"u}r Hochleistungskomponenten in Mischbauweise}, series = {Technomer 2009, 21. Fachtagung {\"u}ber Verarbeitung und Anwendung von Polymeren, Chemnitz, 2009, Plenum, Vortr{\"a}ge, Posterbeitr{\"a}ge, Kurzfassungen}, journal = {Technomer 2009, 21. Fachtagung {\"u}ber Verarbeitung und Anwendung von Polymeren, Chemnitz, 2009, Plenum, Vortr{\"a}ge, Posterbeitr{\"a}ge, Kurzfassungen}, editor = {Gehde, Michael and Wagenknecht, Udo and Bloß, Peter}, publisher = {Institut f{\"u}r Allgemeinen Maschinenbau und Kunststofftechnik, Techn. Univ. [u.a.]}, address = {Chemnitz}, isbn = {978-3-939382-09-6}, pages = {S. 55}, language = {de} } @misc{SeidlitzKrollUlkeWinteretal., author = {Seidlitz, Holger and Kroll, Lothar and Ulke-Winter, Lars and Schumann, Tilo}, title = {Krafteinleitungssysteme bei hybriden Hochleistungskomponenten}, series = {Innovation mit textilen Strukturen, 12. Chemnitzer Textiltechnik-Tagung, 30. September und 1. Oktober 2009}, journal = {Innovation mit textilen Strukturen, 12. Chemnitzer Textiltechnik-Tagung, 30. September und 1. Oktober 2009}, editor = {Meynerts, Peter}, publisher = {Institut f{\"u}r Allgemeinen Maschinenbau und Kunststofftechnik [u.a.]}, address = {Chemnitz}, isbn = {978-3-9812554-3-0}, pages = {220 -- 230}, language = {de} } @misc{SeidlitzKrollUlkeWinter, author = {Seidlitz, Holger and Kroll, Lothar and Ulke-Winter, Lars}, title = {Kraftflussgerechte Verbindungstechniken f{\"u}r Hochleistungskomponenten in Mischbauweise}, series = {Leichtbau-Kongress, Salzburg, 23. - 25. Juni 2009, EuroLITE, Internationale Fachmesse f{\"u}r Leichtbaukonstruktion}, journal = {Leichtbau-Kongress, Salzburg, 23. - 25. Juni 2009, EuroLITE, Internationale Fachmesse f{\"u}r Leichtbaukonstruktion}, publisher = {Hochschule}, address = {Landshut}, language = {de} } @misc{SeidlitzKrollUlkeWinter, author = {Seidlitz, Holger and Kroll, Lothar and Ulke-Winter, Lars}, title = {Load adjusted joining technology for Composite-Metal Hybrids}, series = {Recent Developments in Artificial Intelligence Methods, AI-METH 2009}, journal = {Recent Developments in Artificial Intelligence Methods, AI-METH 2009}, publisher = {Silesian University of Technology}, address = {Gliwice}, isbn = {83-60759-15-4}, doi = {10.1155/2014/958501}, pages = {51 -- 52}, language = {en} } @inproceedings{SchleussSeidlitzFritzscheetal., author = {Schleuß, Leander and Seidlitz, Holger and Fritzsche, Sebastian and Schulze, Marcus and Michailov, Vesselin and Schuhmann, Tilo}, title = {Gewichtsreduzierte Multi-Material-Bauweisen mit Organoblechen}, series = {Tagungsband, 15. Chemnitzer Textiltechnik-Tagung, Chemnitz, Germany, 31.05-01.06.2016}, booktitle = {Tagungsband, 15. Chemnitzer Textiltechnik-Tagung, Chemnitz, Germany, 31.05-01.06.2016}, publisher = {Technische Universit{\"a}t Chemnitz, Professur F{\"o}rdertechnik}, address = {Chemnitz}, isbn = {978-3-945479-06-3}, pages = {112 -- 119}, language = {de} } @misc{BoettgerMeyerMartinetal., author = {B{\"o}ttger, Philipp and Meyer, Marcel and Martin, J{\"o}rg and Otto, Thomas Walter and Geßner, Thomas and Seidlitz, Holger and Kroll, Lothar}, title = {Integrateable light sources based on semiconductor nanocrystal}, series = {Smart Systems Integration 2014, Aachen, 2014}, journal = {Smart Systems Integration 2014, Aachen, 2014}, editor = {Geßner, Thomas}, publisher = {Apprimus Verlag}, address = {Aachen}, isbn = {978-3-86359-201-1}, pages = {451 -- 454}, language = {en} } @inproceedings{HaaseReinholdWolletal., author = {Haase, Florian Vincent and Reinhold, Maximilian and Woll, Ralf and Wolf, Matthias and Seidlitz, Holger}, title = {Reliability capability assessment of cooperative networks using the example of developing demonstrators of structured materials}, series = {Risk, Reliability and Safety: Innovating Theory and Practice, Proceedings of the ESREL 2016, Glasgow (United Kingdom)}, booktitle = {Risk, Reliability and Safety: Innovating Theory and Practice, Proceedings of the ESREL 2016, Glasgow (United Kingdom)}, editor = {Walls, Lesley and Revie, Matthew and Bedford, Tim}, publisher = {CRC Press}, address = {Boca Raton}, isbn = {978-1-138-02997-2}, pages = {1323 -- 1329}, language = {en} } @inproceedings{SeidlitzBambachFritzscheetal., author = {Seidlitz, Holger and Bambach, Markus and Fritzsche, Sebastian and Gerstenberger, Colin}, title = {High load-bearing multi-material-joints for metal sheets and composites by incremental in-situ forming processes}, series = {ESAFORM 2016, proceedings of the 19th International ESAFORM Conference on Material Forming, conference date: 27-29 April 2016, Nantes, France}, booktitle = {ESAFORM 2016, proceedings of the 19th International ESAFORM Conference on Material Forming, conference date: 27-29 April 2016, Nantes, France}, publisher = {AIP Publishing}, address = {Melville, NY}, isbn = {978-0-7354-1427-3}, doi = {10.1063/1.4963464}, language = {en} } @inproceedings{MaqboolElzeSeidlitzetal., author = {Maqbool, Fawad and Elze, Lars and Seidlitz, Holger and Bambach, Markus}, title = {Comparison of Manufacturing of Lightweight Corrugated Sheet Sandwiches by Hydroforming and Incremental Sheet Forming}, series = {ESAFORM 2016, proceedings of the 19th International ESAFORM Conference on Material Forming, conference date: 27-29 April 2016, Nantes, France}, booktitle = {ESAFORM 2016, proceedings of the 19th International ESAFORM Conference on Material Forming, conference date: 27-29 April 2016, Nantes, France}, publisher = {AIP Publishing}, address = {Melville, NY}, isbn = {978-0-7354-1427-3}, doi = {10.1063/1.4963456}, language = {en} } @inproceedings{SeidlitzKukeTsombanis, author = {Seidlitz, Holger and Kuke, Felix and Tsombanis, Nikolas}, title = {Leichtbautechnologien und Mischbauweisen mit Faser-Kunststoff-Verbunden}, series = {Innovationsforum des Regionalen Wachstumskerns Westlausitz, Cottbus, 2016}, booktitle = {Innovationsforum des Regionalen Wachstumskerns Westlausitz, Cottbus, 2016}, pages = {19}, language = {de} } @inproceedings{SeidlitzFritzscheSchleussetal., author = {Seidlitz, Holger and Fritzsche, Sebastian and Schleuß, Leander and Ossenbrink, Ralf and Michailov, Vesselin}, title = {Neuartige F{\"u}getechnologie zum Herstellen von hochbelastbaren Multi-Material-Bauweisen aus textilverst{\"a}rkten Kunststoffen und Metallen bei einseitiger Zug{\"a}nglichkeit der F{\"u}gestelle}, series = {DVS Congress 2016, Große Schweißtechnische Tagung, Vortr{\"a}ge der Veranstaltungen in Leipzig am 19. und 20. September 2016}, booktitle = {DVS Congress 2016, Große Schweißtechnische Tagung, Vortr{\"a}ge der Veranstaltungen in Leipzig am 19. und 20. September 2016}, publisher = {DVS-Verlag}, address = {D{\"u}sseldorf}, isbn = {978-3-945023-74-7}, pages = {424 -- 428}, language = {de} } @inproceedings{FritzscheSeidlitzWinkelmannetal., author = {Fritzsche, Sebastian and Seidlitz, Holger and Winkelmann, Kai and Michailov, Vesselin}, title = {Structural reinforced FRP sandwich constructions for lightweight floor panels}, series = {Conference papers, APT '15, 11th International Conference Advances in Plastics Technology, Sosnowiec, 13 - 15 October 2015}, booktitle = {Conference papers, APT '15, 11th International Conference Advances in Plastics Technology, Sosnowiec, 13 - 15 October 2015}, editor = {Pająk, Anna}, address = {Gliwice}, isbn = {978-83-63555-47-4}, language = {en} } @inproceedings{GerstenbergerSeidlitzOsieckietal., author = {Gerstenberger, Colin and Seidlitz, Holger and Osiecki, Tomasz and Kroll, Lothar}, title = {Bionic Inspired High Stressable Joints for Multi-material Constructions with FRP and Metals}, series = {Materials Science Engineering (MSE 2014), Darmstadt, 2014}, booktitle = {Materials Science Engineering (MSE 2014), Darmstadt, 2014}, language = {en} } @inproceedings{SchulzeSeidlitzKoenigetal., author = {Schulze, Marcus and Seidlitz, Holger and K{\"o}nig, Franziska and Weiß, Sabine}, title = {Nanoindentation measurements of PVD coated multilayer constructions}, series = {Programme and proceedings of the 22nd Winter International Scintific Conference on Achivements in Mechanical and Materials Engineering (AMME'15), Gliwice - Zakopane (Poland), 2015}, booktitle = {Programme and proceedings of the 22nd Winter International Scintific Conference on Achivements in Mechanical and Materials Engineering (AMME'15), Gliwice - Zakopane (Poland), 2015}, editor = {Dobrzański, Leszek A.}, publisher = {Gliwice}, address = {International OCSCO World Press}, isbn = {978-83-63553-39-5}, language = {en} } @misc{SeidlitzSimonElzeetal., author = {Seidlitz, Holger and Simon, Sylvio and Elze, Lars and Schulze, Marcus}, title = {Herstellung von strukturierten Leichtbaukomponenten}, language = {de} } @misc{SeidlitzElzeSchulze, author = {Seidlitz, Holger and Elze, Lars and Schulze, Marcus}, title = {Eigenschaften strukturierter Leichtbaukomponenten}, language = {de} } @inproceedings{HackertGerstenbergerOsieckietal., author = {Hackert, Alexander and Gerstenberger, Colin and Osiecki, Tomasz and Seidlitz, Holger}, title = {Hybrid sandwich composites with porous aluminum core and thermoplastic fiber-reinforced composite top layers}, series = {Proceedings of the 23rd Annual International Conference on Composites/Nano Engineering (ICCE23), Chengdu (China), 2015}, booktitle = {Proceedings of the 23rd Annual International Conference on Composites/Nano Engineering (ICCE23), Chengdu (China), 2015}, pages = {247 -- 248}, language = {en} } @inproceedings{OsieckiGerstenbergerHackertetal., author = {Osiecki, Tomasz and Gerstenberger, Colin and Hackert, Alexander and Kroll, Lothar and Seidlitz, Holger}, title = {Thermoplastic fiber reinforced/metal-hybrid laminates for structural lightweight applications}, series = {Proceedings of the 23rd Annual International Conference on Composites/Nano Engineering (ICCE23), Chengdu (China), 2015}, booktitle = {Proceedings of the 23rd Annual International Conference on Composites/Nano Engineering (ICCE23), Chengdu (China), 2015}, pages = {595 -- 596}, language = {en} } @inproceedings{GerstenbergerHackertOsieckietal., author = {Gerstenberger, Colin and Hackert, Alexander and Osiecki, Tomasz and Kroll, Lothar and Seidlitz, Holger}, title = {Load adjusted fiber reinforced polymer/metal joints in cathodic dip paint conditions}, series = {Proceedings of the 23rd Annual International Conference on Composites/Nano Engineering (ICCE23), Chengdu (China), 2015}, booktitle = {Proceedings of the 23rd Annual International Conference on Composites/Nano Engineering (ICCE23), Chengdu (China), 2015}, pages = {227 -- 228}, language = {en} } @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{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{SanthanakrishnanBalakrishnanSeidlitz, author = {Santhanakrishnan Balakrishnan, Venkateswaran and Seidlitz, Holger}, title = {Potential repair techniques for automotive composites: A review}, series = {Composites Part B: Engineering}, journal = {Composites Part B: Engineering}, number = {145}, issn = {1359-8368}, doi = {10.1016/j.compositesb.2018.03.016}, pages = {28 -- 38}, abstract = {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.}, language = {en} } @inproceedings{SeidlitzKukeTsombanis, author = {Seidlitz, Holger and Kuke, Felix and Tsombanis, Nikolas}, title = {Advanced joining technology for the production of highly stressable lightweight structures, with fiber-reinforced plastics and metal}, series = {3rd International MERGE Technologies Conference (IMTC), Chemnitz, 2017}, volume = {1}, booktitle = {3rd International MERGE Technologies Conference (IMTC), Chemnitz, 2017}, number = {2}, doi = {10.21935/tls.v1i2.76}, pages = {54 -- 67}, abstract = {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.}, language = {en} } @misc{SchleussSeidlitzMichailov, author = {Schleuß, Leander and Seidlitz, Holger and Michailov, Vesselin}, title = {Neue F{\"u}getechnologie f{\"u}r Mischverbindungen}, language = {de} } @misc{SanthanakrishnanBalakrishnanSeidlitzWartigetal., author = {Santhanakrishnan Balakrishnan, Venkateswaran and Seidlitz, Holger and Wartig, Kevin and Tsombanis, Nikolas}, title = {Influence of processing parameters on the impact behaviour of glass/polyamide-6 composite}, series = {Composites Part B: Engineering}, volume = {159}, journal = {Composites Part B: Engineering}, issn = {1359-8368}, doi = {10.1016/j.compositesb.2018.09.064}, pages = {292 -- 299}, abstract = {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.}, language = {en} } @misc{SanthanakrishnanBalakrishnanSeidlitzWeiss, author = {Santhanakrishnan Balakrishnan, Venkateswaran and Seidlitz, Holger and Weiß, Sabine}, title = {Layup Configuration Effect on Notch Residual Strength in Composite Laminates}, series = {Materials}, volume = {11}, journal = {Materials}, number = {2}, issn = {1996-1944}, doi = {10.3390/ma11020308}, pages = {12}, abstract = {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.}, language = {en} } @inproceedings{FritzscheKloshekDietzetal., author = {Fritzsche, Sebastian and Kloshek, Alexander and Dietz, Eric and Michailov, Vesselin and Seidlitz, Holger and Ossenbrink, Ralf}, title = {SLM gefertigte Verbindungsknoten f{\"u}r Leichtbaurahmenelemente}, series = {DVS Congress 2018 : Große Schweißtechnische Tagung, DVS-Studentenkongress, Vortr{\"a}ge der Veranstaltungen in Friedrichshafen am 17. und 18. September 2018}, booktitle = {DVS Congress 2018 : Große Schweißtechnische Tagung, DVS-Studentenkongress, Vortr{\"a}ge der Veranstaltungen in Friedrichshafen am 17. und 18. September 2018}, number = {264}, publisher = {DVS Media GmbH}, address = {D{\"u}sseldorf}, isbn = {978-3-96144-036-8}, abstract = {SLM gefertigte Verbindungsknoten f{\"u}r Leichtbaurahmenelemente}, language = {de} } @misc{YellurSeidlitzKukeetal., author = {Yellur, Manoja Rao and Seidlitz, Holger and Kuke, Felix and Wartig, Kevin and Tsombanis, Nikolas}, title = {A low velocity impact study on press formed thermoplastic honeycomb sandwich panels}, series = {Composite Structures}, volume = {225}, journal = {Composite Structures}, issn = {0263-8223}, doi = {10.1016/j.compstruct.2019.111061}, pages = {111061}, abstract = {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.}, language = {en} } @misc{SanthanakrishnanBalakrishnanObrosovKukeetal., author = {Santhanakrishnan Balakrishnan, Venkateswaran and Obrosov, Aleksei and Kuke, Felix and Seidlitz, Holger and Weiß, Sabine}, title = {Influence of metal surface preparation on the flexural strength and impact damage behaviour of thermoplastic FRP reinforced metal laminate made by press forming}, series = {Composites Part B: Engineering}, volume = {173}, journal = {Composites Part B: Engineering}, issn = {1359-8368}, doi = {10.1016/j.compositesb.2019.05.094}, abstract = {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.}, language = {en} } @misc{SanthanakrishnanBalakrishnanHartRawungBuhletal., author = {Santhanakrishnan Balakrishnan, Venkateswaran and Hart-Rawung, Thawin and Buhl, Johannes and Seidlitz, Holger and Bambach, Markus}, title = {Impact and damage behaviour of FRP-metal hybrid laminates made by the reinforcement of glass fibers on 22MnB5 metal surface}, series = {Composites Science and Technology}, volume = {Vol. 187}, journal = {Composites Science and Technology}, issn = {1879-1050}, doi = {10.1016/j.compscitech.2019.107949}, pages = {15}, language = {en} } @misc{RoeschSeidlitzPfeiferetal., author = {R{\"o}sch, Janina J. and Seidlitz, Holger and Pfeifer, Robin and Burlefinger, Hubert and Maurer, Thomas}, title = {Preform joints in embroidered fabrics - influence on the mechanical properties}, series = {Advanced Composite Materials}, journal = {Advanced Composite Materials}, pages = {1 -- 16}, abstract = {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.}, 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{HannanSeidlitzMuelleretal., author = {Hannan, Azmin Nasrin and Seidlitz, Holger and M{\"u}ller, Marco and Krenz, Jonas}, title = {Investigations of technical challenges in compounding of recycled carbon fibers}, series = {Zarzadzanie Przedsiebiorstwem. Enterprise Management}, volume = {26}, journal = {Zarzadzanie Przedsiebiorstwem. Enterprise Management}, number = {2}, issn = {1643-4773}, doi = {10.25961/ent.manag.26.01.03}, pages = {7 -- 12}, abstract = {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.}, language = {en} } @incollection{SeidlitzUlkeWinterKukeetal., author = {Seidlitz, Holger and Ulke-Winter, Lars and Kuke, Felix and Ost, Lucas}, title = {Material and Load Path Appropriate Joining Techniques for FRP/Metal Hybrid Structures}, series = {Welding - Materials, Fabrication Processes, and Industry 5.0}, booktitle = {Welding - Materials, Fabrication Processes, and Industry 5.0}, editor = {Kumar, Sanjeev}, edition = {1. Auflage}, publisher = {IntechOpen}, address = {London}, isbn = {978-1-83769-870-7}, doi = {10.5772/intechopen.1002239}, abstract = {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.}, language = {en} } @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} } @misc{ErekathSeidlitzSchreineretal., author = {Erekath, Swathi and Seidlitz, Holger and Schreiner, Monika and Dreyer, Christian}, title = {Food for future: Exploring cutting-edge technology and practices in vertical farm}, series = {Sustainable Cities and Society}, volume = {106}, journal = {Sustainable Cities and Society}, issn = {2210-6707}, doi = {10.1016/j.scs.2024.105357}, abstract = {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.}, language = {en} } @misc{RecupidoLamaSteffenetal., author = {Recupido, Federica and Lama, Giuseppe Cesare and Steffen, Sebastian and Dreyer, Christian and Seidlitz, Holger and Russo, Vincenzo and Lavorgna, Marino and De Luca Bossa, Ferdinando and Silvano, Selena and Boggioni, Laura and Verdolotti, Letizia}, title = {Efficient recycling pathway of bio-based composite polyurethane foams via sustainable diamine}, series = {Ecotoxicology and Environmental Safety}, volume = {269}, journal = {Ecotoxicology and Environmental Safety}, issn = {0147-6513}, doi = {10.1016/j.ecoenv.2023.115758}, abstract = {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.}, language = {en} } @misc{BłędzkiSeidlitzUrbaniaketal., author = {Błędzki, Andrzej and Seidlitz, Holger and Urbaniak, Magdalena and K{\"o}hler, Mathias and Adamcio, Andrzej and Sobczyk, Marcin and Demski, Szymon and Boczkowska, Anna}, title = {Reusing and recycling of composite wind turbine blades. A review of current practices and prospects. Part 1. Academic research}, series = {Przemysł chemiczny}, volume = {103}, journal = {Przemysł chemiczny}, number = {2}, issn = {0033-2496}, doi = {10.15199/62.2024.2.2}, pages = {225 -- 233}, abstract = {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.}, language = {en} } @misc{BłędzkiSeidlitzUrbaniaketal., author = {Błędzki, Andrzej and Seidlitz, Holger and Urbaniak, Magdalena and K{\"o}hler, Mathias and Adamcio, Andrzej and Sobczyk, Marcin and Demski, Szymon and Boczkowska, Anna}, title = {Reusing and recycling of composite wind turbine blades. A review of current practices and prospects. Part 2. Industrial activities}, series = {Przemysł chemiczny}, volume = {103}, journal = {Przemysł chemiczny}, number = {2}, issn = {0033-2496}, doi = {10.15199/62.2024.2.3}, pages = {234 -- 240}, abstract = {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}, language = {en} } @misc{BłędzkiSeidlitzUrbaniaketal., author = {Błędzki, Andrzej and Seidlitz, Holger and Urbaniak, Magdalena and K{\"o}hler, Mathias and Adamcio, Andrzej and Sobczyk, Marcin and Demski, Szymon and Boczkowska, Anna}, title = {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}, series = {Przemysł chemiczny}, volume = {103}, journal = {Przemysł chemiczny}, number = {2}, issn = {0033-2496}, doi = {10.15199/62.2024.2.4}, pages = {241 -- 250}, abstract = {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.}, language = {en} } @misc{MiahKloshekOssenbrinketal., author = {Miah, Kamal Uddin Mohammad and Kloshek, Alexander and Ossenbrink, Ralf and Seidlitz, Holger}, title = {Selective Laser Melting of Pure Copper (Cu-ETP)}, series = {4th Symposium on Materials and Additive Manufacturing, Additive 2024, 22. - 24. Mai 2024, Book of Abstracts}, journal = {4th Symposium on Materials and Additive Manufacturing, Additive 2024, 22. - 24. Mai 2024, Book of Abstracts}, publisher = {Deutsche Gesellschaft f{\"u}r Materialkunde (DGM) e.V.}, address = {Bremen, Berlin}, isbn = {978-3-88355-440-2}, pages = {19}, abstract = {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.}, language = {en} } @misc{KehmWasilewskiMiahetal., author = {Kehm, Christian and Wasilewski, Eric and Miah, Kamal Uddin Mohammad and Ossenbrink, Ralf and Seidlitz, Holger}, title = {Effects of extended shielding gas coverage on component contour accuracy in Wire Arc Additive Manufacturing}, series = {4th Symposium on Materials and Additive Manufacturing, Additive 2024, 22. - 24. Mai 2024, Book of Abstracts}, journal = {4th Symposium on Materials and Additive Manufacturing, Additive 2024, 22. - 24. Mai 2024, Book of Abstracts}, publisher = {Deutsche Gesellschaft f{\"u}r Materialkunde (DGM) e.V.}, address = {Bremen, Berlin}, isbn = {978-3-88355-440-2}, pages = {29}, abstract = {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.}, language = {en} } @misc{NikitinTurabovErmilovaetal., author = {Nikitin, Alexander and Turabov, Dashqin and Ermilova, Evgeniia and Evdokimov, Anton and Ossenbrink, Ralf and Seidlitz, Holger}, title = {Using dynamic resistance to predict electrode surface degradation in resistance spot welding of 5182 aluminum alloy}, series = {Welding in the World}, volume = {69}, journal = {Welding in the World}, doi = {10.1007/s40194-024-01872-9}, pages = {449 -- 458}, abstract = {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.}, language = {en} } @misc{RueppelDornKukeetal., author = {R{\"u}ppel, Gernot Wilhelm and Dorn, Oliver Niklas and Kuke, Felix and Ulke-Winter, Lars and Seidlitz, Holger}, title = {Optical tape detection using an IR camera to create a digital twin of rotationally symmetrical wet-wound FRP components}, series = {Journal of Engineering 360}, volume = {1 (2024)}, journal = {Journal of Engineering 360}, number = {1/24}, publisher = {Index Copernicus}, issn = {3071-7507}, doi = {10.5604/01.3001.0054.8851}, pages = {46 -- 57}, abstract = {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.}, language = {en} } @misc{SztorchRomanczukRuszukGłowackaetal., author = {Sztorch, Bogna and Romanczuk-Ruszuk, Eliza and Głowacka, Julia and Kustosz, Magdalena and Osiecki, Tomasz and Jakubowska, Paulina and Seidlitz, Holger and Przekop, Robert E.}, title = {Improving the processing and mechanical properties of 3D printable biocomposite based on polylactide, sediment rock, and natural beeswax}, series = {Polymer Bulletin}, volume = {2024}, journal = {Polymer Bulletin}, publisher = {Springer Science and Business Media LLC}, issn = {0170-0839}, doi = {10.1007/s00289-024-05614-1}, pages = {31}, abstract = {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).}, language = {en} } @misc{OstSeidlitzUlkeWinteretal., author = {Ost, Lucas and Seidlitz, Holger and Ulke-Winter, Lars and Kuke, Felix}, title = {Development of a spherical high-pressure tank for hydrogen storage in mobile and stationary applications}, series = {Energy Technology}, journal = {Energy Technology}, publisher = {Wiley}, issn = {2194-4288}, doi = {10.1002/ente.202300942}, pages = {5}, abstract = {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.}, language = {en} } @misc{HajhaririEberweinPerroneetal., author = {Hajhariri, Aliasghar and Eberwein, Robert and Perrone, Luca Pakj and Cozzani, Valerio and Otremba, Frank and Seidlitz, Holger}, title = {Study the impact of spacer at thermal degradation process of MLI-based insulation in fire condition}, series = {Journal of Loss Prevention in the Process Industries}, volume = {92}, journal = {Journal of Loss Prevention in the Process Industries}, publisher = {Elsevier BV}, issn = {0950-4230}, doi = {10.1016/j.jlp.2024.105461}, pages = {240 -- 248}, abstract = {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.}, 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{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} }