Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Bemerkung Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Zugriffsart Link Abteilungen OPUS4-10837 Wissenschaftlicher Artikel Herssens, Nolan, ; Cowburn, James, ; Albracht, Kirsten, albracht@fh-aachen.de; Braunstein, Bjoern, ; Cazzola, Dario, ; Colyer, Steffi, ; Minetti, Alberto E., ; Pavei, Gaspare, ; Rittweger, Jörn, ; Weber, Tobias, ; Green, David A., Cattaneo, Luigi Movement in low gravity environments (MoLo) programme - the MoLo-L.O.O.P. study protocol Exposure to prolonged periods in microgravity is associated with deconditioning of the musculoskeletal system due to chronic changes in mechanical stimulation. Given astronauts will operate on the Lunar surface for extended periods of time, it is critical to quantify both external (e.g., ground reaction forces) and internal (e.g., joint reaction forces) loads of relevant movements performed during Lunar missions. Such knowledge is key to predict musculoskeletal deconditioning and determine appropriate exercise countermeasures associated with extended exposure to hypogravity. San Francisco Plos One 2022 24 Seiten PLOS ONE / Public Library of Science 10.1371/journal.pone.0278051 https://doi.org/10.1371/journal.pone.0278051 Fachbereich Medizintechnik und Technomathematik OPUS4-9966 Wissenschaftlicher Artikel Richter, Charlotte, c.richter@fh-aachen.de; Braunstein, Bjoern, ; Staeudle, Benjamin, ; Attias, Julia, ; Suess, Alexander, ; Weber, Tobias, ; Mileva, Katya N., ; Rittweger, Joern, ; Green, David A., ; Albracht, Kirsten, albracht@fh-aachen.de Contractile behavior of the gastrocnemius medialis muscle during running in simulated hypogravity Vigorous exercise countermeasures in microgravity can largely attenuate muscular degeneration, albeit the extent of applied loading is key for the extent of muscle wasting. Running on the International Space Station is usually performed with maximum loads of 70% body weight (0.7 g). However, it has not been investigated how the reduced musculoskeletal loading affects muscle and series elastic element dynamics, and thereby force and power generation. Therefore, this study examined the effects of running on the vertical treadmill facility, a ground-based analog, at simulated 0.7 g on gastrocnemius medialis contractile behavior. The results reveal that fascicle−series elastic element behavior differs between simulated hypogravity and 1 g running. Whilst shorter peak series elastic element lengths at simulated 0.7 g appear to be the result of lower muscular and gravitational forces acting on it, increased fascicle lengths and decreased velocities could not be anticipated, but may inform the development of optimized running training in hypogravity. However, whether the alterations in contractile behavior precipitate musculoskeletal degeneration warrants further study. New York Springer Nature 2021 7 Seiten npj Microgravity 7 Corresponding author: Charlotte Richter Article number: 32 10.1038/s41526-021-00155-7 weltweit https://doi.org/10.1038/s41526-021-00155-7 Fachbereich Medizintechnik und Technomathematik OPUS4-9284 Wissenschaftlicher Artikel Hailer, Benjamin, ; Weber, Tobias, t.weber@fh-aachen.de; Neveling, Sebastian, ; Dera, Samuel, ; Arent, Jan-Christoph, ; Middendorf, Peter, Development of a test device to determine the frictional behavior between honeycomb and prepreg layers under realistic manufacturing conditions In the friction tests between honeycomb with film adhesive and prepreg, the relative displacement occurs between the film adhesive and the prepreg. The film adhesive does not shift relative to the honeycomb. This is consistent with the core crush behavior where the honeycomb moves together with the film adhesive, as can be seen in Figure 2(a). The pull-through forces of the friction measurements between honeycomb and prepreg at 1 mm deformation are plotted in Figure 17(a). While the friction at 100°C is similar to the friction at 120°C, it decreases significantly at 130°C and exhibits a minimum at 140°C. At 150°C, the friction rises again slightly and then sharply at 160°C. Since the viscosity of the M18/1 prepreg resin drops significantly before it cures [23], the minimum friction at 140°C could result from a minimum viscosity of the mixture of prepreg resin and film adhesive before the bond subsequently cures. Figure 17(b) shows the mean value curve of the friction measurements at 140°C. The error bars, which represent the standard deviation, reveal the good repeatability of the tests. The force curve is approximately horizontal between 1 mm and 2 mm. The friction then slightly rises. As with interlaminar friction measurements, this could be due to the fact that resin is removed by friction and the proportion of boundary lubrication increases. Figure 18 shows the surfaces after the friction measurement. The honeycomb cell walls are clearly visible in the film adhesive. There are areas where the film adhesive is completely removed and the carrier material of the film adhesive becomes visible. In addition, the viscosity of the resin changes as the curing progresses during the friction test. This can also affect the force-displacement curve. London Sage 2020 26 Journal of Sandwich Structures & Materials Volume 23, Issue 7 3017 3043 10.1177/1099636220923986 bezahl https://doi.org/10.1177/1099636220923986 Fachbereich Luft- und Raumfahrttechnik OPUS4-9285 Wissenschaftlicher Artikel Weber, Tobias, t.weber@fh-aachen.de; Englhard, Markus, ; Arent, Jan-Christoph, ; Hausmann, Joachim, An experimental characterization of wrinkling generated during prepreg autoclave manufacturing using caul plates 2019 16 Journal of Composite Materials 53 26-27 3757 3773 10.1177/0021998319846556 bezahl https://doi.org/10.1177/0021998319846556 Fachbereich Luft- und Raumfahrttechnik OPUS4-9286 Dissertation Weber, Tobias, Herstellprozesssimulation zur Vorhersage der Faltenbildung in der Prepreg-Autoklav-Fertigung Kaiserslautern Technische Universität Kaiserslautern 2019 XIV, 207 Seiten 978-3-944440-24-8 Dissertation, Kaiserslautern, Technische Universität Kaiserslautern, 2017 urn:nbn:de:hbz:386-kluedo-54923 https://nbn-resolving.org/urn:nbn:de:hbz:386-kluedo-54923 Fachbereich Luft- und Raumfahrttechnik OPUS4-9287 Wissenschaftlicher Artikel Otten, Dennis, ; Weber, Tobias, t.weber@fh-aachen.de; Arent, Jan-Christoph, Manufacturing Process Simulation - On Its Way to Industrial Application Manufacturing process simulation (MPS) has become more and more important for aviation and the automobile industry. A highly competitive market requires the use of high performance metals and composite materials in combination with reduced manufacturing cost and time as well as a minimization of the time to market for a new product. However, the use of such materials is expensive and requires sophisticated manufacturing processes. An experience based process and tooling design followed by a lengthy trial-and-error optimization is just not contemporary anymore. Instead, a tooling design process aided by simulation is used more often. This paper provides an overview of the capabilities of MPS in the fields of sheet metal forming and prepreg autoclave manufacturing of composite parts summarizing the resulting benefits for tooling design and manufacturing engineering. The simulation technology is explained briefly in order to show several simplification and optimization techniques for developing industrialized simulation approaches. Small case studies provide examples of an efficient application on an industrial scale. Daytona Beach, Fla. Embry-Riddle Aeronautical University 2018 International Journal of Aviation, Aeronautics, and Aerospace 5 2 10.15394/ijaaa.2018.1217 weltweit https://doi.org/10.15394/ijaaa.2018.1217 Fachbereich Luft- und Raumfahrttechnik OPUS4-9288 Wissenschaftlicher Artikel Weber, Tobias, t.weber@fh-aachen.de; Ruff-Stahl, Hans-Joachim K., Advances in Composite Manufacturing of Helicopter Parts 2017 International Journal of Aviation, Aeronautics, and Aerospace 4 1 10.15394/ijaaa.2017.1153 weltweit https://doi.org/10.15394/ijaaa.2017.1153 Fachbereich Luft- und Raumfahrttechnik OPUS4-9291 Wissenschaftlicher Artikel Weber, Tobias, t.weber@fh-aachen.de; Arent, Jan-Christoph, ; Steffen, Lucas, ; Balvers, Johannes M., ; Duhovic, Miro, Thermal optimization of composite autoclave molds using the shift factor approach for boundary condition estimation London Sage 2017 14 Journal of Composite Materials 51 12 1753 1767 10.1177/0021998317699868 weltweit https://doi.org/10.1177/0021998317699868 Fachbereich Luft- und Raumfahrttechnik OPUS4-9292 Konferenzveröffentlichung Otten, D., ; Schmidt, M., ; Weber, Tobias, t.weber@fh-aachen.de Advances in Determination of Material Parameters for Functional Simulations Based on Process Simulations 2016 7 SAMPE Europe Conference 16 Liege 978-1-5108-3800-0 570 577 Fachbereich Luft- und Raumfahrttechnik OPUS4-9293 Konferenzveröffentlichung Weber, Tobias, t.weber@fh-aachen.de; Tellis, Jane J., ; Duhovic, Miro, Characterization of tool-part-interaction an interlaminar friction for manufacturing process simulation 2016 6 ECCM 17, 17th European Conference on Composite Materials, München, DE, Jun 26-30, 2016 978-3-00-053387-7 1 7 Fachbereich Luft- und Raumfahrttechnik OPUS4-9294 Wissenschaftlicher Artikel Weber, Tobias, t.weber@fh-aachen.de; Arent, Jan-Christoph, ; Münch, Lukas, ; Duhovic, Miro, ; Balvers, Johannes M., A fast method for the generation of boundary conditions for thermal autoclave simulation Manufacturing process simulation enables the evaluation and improvement of autoclave mold concepts early in the design phase. To achieve a high part quality at low cycle times, the thermal behavior of the autoclave mold can be investigated by means of simulations. Most challenging for such a simulation is the generation of necessary boundary conditions. Heat-up and temperature distribution in an autoclave mold are governed by flow phenomena, tooling material and shape, position within the autoclave, and the chosen autoclave cycle. This paper identifies and summarizes the most important factors influencing mold heat-up and how they can be introduced into a thermal simulation. Thermal measurements are used to quantify the impact of the various parameters. Finally, the gained knowledge is applied to develop a semi-empirical approach for boundary condition estimation that enables a simple and fast thermal simulation of the autoclave curing process with reasonably high accuracy for tooling optimization. Amsterdam Elsevier 2016 9 Composites Part A 88 216 225 10.1016/j.compositesa.2016.05.036 bezahl https://doi.org/10.1016/j.compositesa.2016.05.036 Fachbereich Luft- und Raumfahrttechnik OPUS4-9295 Konferenzveröffentlichung Hailer, Benjamin, ; Weber, Tobias, t.weber@fh-aachen.de; Arent, Jan-Christoph, Manufacturing Process Simulation for Autoclave-Produced Sandwich Structures 2019 7 Proceedings of SAMPE Europe Conference 2019, Nantes, France 1 8 Fachbereich Luft- und Raumfahrttechnik OPUS4-9296 Konferenzveröffentlichung Weber, Tobias, t.weber@fh-aachen.de; Englhard, Markus, ; Hailer, Benjamin, ; Arent, Jan-Christoph, Manufacturing Process Simulation for the Prediction of Tool-Part-Interaction and Ply Wrinkling 2019 9 Proceedings of SAMPE Europe Conference 2019, Nantes, France 1 10 Fachbereich Luft- und Raumfahrttechnik OPUS4-9297 Konferenzveröffentlichung Weber, Tobias, t.weber@fh-aachen.de; Englhard, Markus, ; Hailer, Benjamin, ; Arent, Jan-Christoph, Manufacturing Process Simulation for the Prediction of Tool-Part-Interaction and Ply Wrinkling 2015 9 Proceedings of SAMPE Europe Conference, Amiens , France 1 10 Fachbereich Luft- und Raumfahrttechnik OPUS4-9298 Konferenzveröffentlichung Weber, Tobias, t.weber@fh-aachen.de Manufacturing Process Simulation for Tooling Optimization: Reduction of Quality Issues During Autoclave Manufacturing of Composite Parts 2015 7 Proceedings of SAMPE Europe Conference 2015, Amiens, France 1 8 Fachbereich Luft- und Raumfahrttechnik OPUS4-9299 Konferenzveröffentlichung Otten, D., ; Schmid, M., ; Weber, Tobias, t.weber@fh-aachen.de Advances In Sheet Metal-Forming: Reduction Of Tooling Cost By Methodical Optimization 2015 Proceedings of SAMPE Europe Conference, Amiens , France Fachbereich Luft- und Raumfahrttechnik OPUS4-9804 Konferenzveröffentlichung Englhard, Markus, ; Weber, Tobias, t.weber@fh-aachen.de; Arent, Jan-Christoph, Efficiency enhancement for CFRP-Prepregautoclave manufacturing by means of simulation-assisted loading optimization A new method for improved autoclave loading within the restrictive framework of helicopter manufacturing is proposed. It is derived from experimental and numerical studies of the curing process and aims at optimizing tooling positions in the autoclave for fast and homogeneous heat-up. The mold positioning is based on two sets of information. The thermal properties of the molds, which can be determined via semi-empirical thermal simulation. The second information is a previously determined distribution of heat transfer coefficients inside the autoclave. Finally, an experimental proof of concept is performed to show a cycle time reduction of up to 31% using the proposed methodology. 2021 8 Seiten Proceedings of SAMPE Europe Conference 2021 Proceedings of SAMPE Europe Conference 2021, Baden/Zürich, Schweiz, 29. bis 30. September 2021 Fachbereich Luft- und Raumfahrttechnik OPUS4-10972 Wissenschaftlicher Artikel Richter, Charlotte, ; Braunstein, Bjoern, ; Stäudle, Benjamin, ; Attias, Julia, ; Suess, Alexander, ; Weber, Tobias, ; Mileva, Katja N., ; Rittweger, Joern, ; Green, David A., ; Albracht, Kirsten, albracht@fh-aachen.de Gastrocnemius medialis contractile behavior is preserved during 30% body weight supported gait training Rehabilitative body weight supported gait training aims at restoring walking function as a key element in activities of daily living. Studies demonstrated reductions in muscle and joint forces, while kinematic gait patterns appear to be preserved with up to 30% weight support. However, the influence of body weight support on muscle architecture, with respect to fascicle and series elastic element behavior is unknown, despite this having potential clinical implications for gait retraining. Eight males (31.9 ± 4.7 years) walked at 75% of the speed at which they typically transition to running, with 0% and 30% body weight support on a lower-body positive pressure treadmill. Gastrocnemius medialis fascicle lengths and pennation angles were measured via ultrasonography. Additionally, joint kinematics were analyzed to determine gastrocnemius medialis muscle-tendon unit lengths, consisting of the muscle's contractile and series elastic elements. Series elastic element length was assessed using a muscle-tendon unit model. Depending on whether data were normally distributed, a paired t-test or Wilcoxon signed rank test was performed to determine if body weight supported walking had any effects on joint kinematics and fascicle-series elastic element behavior. Walking with 30% body weight support had no statistically significant effect on joint kinematics and peak series elastic element length. Furthermore, at the time when peak series elastic element length was achieved, and on average across the entire stance phase, muscle-tendon unit length, fascicle length, pennation angle, and fascicle velocity were unchanged with respect to body weight support. In accordance with unchanged gait kinematics, preservation of fascicle-series elastic element behavior was observed during walking with 30% body weight support, which suggests transferability of gait patterns to subsequent unsupported walking. Lausanne Frontiers 2021 Artikel 614559 Frontiers in Sports and Active Living 2021 2 10.3389/fspor.2020.614559 weltweit https://doi.org/10.3389/fspor.2020.614559 Fachbereich Medizintechnik und Technomathematik OPUS4-10976 Wissenschaftlicher Artikel Richter, Charlotte, ; Braunstein, Björn, ; Stäudle, Benjamin, ; Attias, Julia, ; Süss, Alexander, ; Weber, Tobias, ; Mileva, Katya N., ; Rittweger, Jörn, ; Green, David A., ; Albracht, Kirsten, Albracht@fh-aachen.de Gastrocnemius medialis contractile behavior during running differs between simulated Lunar and Martian gravities The international partnership of space agencies has agreed to proceed forward to the Moon sustainably. Activities on the Lunar surface (0.16 g) will allow crewmembers to advance the exploration skills needed when expanding human presence to Mars (0.38 g). Whilst data from actual hypogravity activities are limited to the Apollo missions, simulation studies have indicated that ground reaction forces, mechanical work, muscle activation, and joint angles decrease with declining gravity level. However, these alterations in locomotion biomechanics do not necessarily scale to the gravity level, the reduction in gastrocnemius medialis activation even appears to level off around 0.2 g, while muscle activation pattern remains similar. Thus, it is difficult to predict whether gastrocnemius medialis contractile behavior during running on Moon will basically be the same as on Mars. Therefore, this study investigated lower limb joint kinematics and gastrocnemius medialis behavior during running at 1 g, simulated Martian gravity, and simulated Lunar gravity on the vertical treadmill facility. The results indicate that hypogravity-induced alterations in joint kinematics and contractile behavior still persist between simulated running on the Moon and Mars. This contrasts with the concept of a ceiling effect and should be carefully considered when evaluating exercise prescriptions and the transferability of locomotion practiced in Lunar gravity to Martian gravity. London Springer Nature 2021 13 Seiten Scientific reports 11 Corresponding author: Charlotte Richter Article number: 22555 10.1038/s41598-021-00527-9 weltweit https://doi.org/10.1038/s41598-021-00527-9 Fachbereich Medizintechnik und Technomathematik