@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} }