TY - GEN A1 - Briem, Ulrich T1 - Lebensdauerverhalten von Seildrähten T2 - 13. Branchentag-Draht, 15. Sept. 2020 Y1 - 2020 ER - TY - GEN A1 - Schwanzer, Peter A1 - Dietrich, Markus A1 - Gaderer, Matthias A1 - Rabl, Hans-Peter T1 - Detektion unterschiedlicher Medien in Gasoline Particulate Filter (GPF) mit Hilfe eines Radio-Frequenz (RF-) Sensors T2 - Bayerische Wissenschaftsforum - BayWISS 2020 Y1 - 2020 UR - https://mobilitaet-verkehr.baywiss.de/fileadmin/verbundkolleg/mobilitaet-verkehr/poster/Schwanzer_Peter.pdf ER - TY - BOOK A1 - Altmann, Robert A1 - Gebhard, Jürgen A1 - Emberger, Peter A1 - Thuneke, Klaus A1 - Rabl, Hans-Peter A1 - Remmele, Edgar T1 - Zünd- und Brennverhalten von Pflanzenölkraftstoff und Übertragung auf einen Motor der Abgasstufe V N2 - Durch den Ersatz von Dieselkraftstoff durch Rapsölkraftstoff (R100) können Treibhausgasemissionen reduziert werden. Für einen störungsfreien Betrieb eines Motors mit Rapsölkraftstoff sind jedoch Modifikationen an Motorkomponenten und Motorsteuergerät notwendig, um eine effiziente Verbrennung im Motor zu erreichen. Ziel des Vorhabens ist die Erarbeitung von Grundlagen zur Auslegung der Motorsteuerung pflanzenöltauglicher Offroad-Motoren mit moderner Abgasnachbehandlung mit anschließender entsprechender Abstimmung der Motorapplikation am Prüfstand. Grundlegende Untersuchungen der physikalischen Prozessabläufe von R100 bei der Einspritzung werden an einem hydraulischen Druckanstiegsanalysator (HDA) und einer Hochdruck-Hochtemperatur-Kammer (HDHT-Kammer) durchgeführt. Unterschiede im Zünd- und Brennverhalten werden in einer Konstantvolumenbrennkammer untersucht. Abschließend werden die Erkenntnisse am Motorenprüfstand auf einen DEUTZ-Motor übertragen, dessen Einspritzsystem auch bei den grundlegenden Untersuchungen verwendet wurde. Die Ergebnisse zeigen, dass das Einspritzverhalten von R100 eine höhere Sensitivität gegenüber Kraftstofftemperaturvariationen aufweist als Dieselkraftstoff. Bei niedrigen raftstofftemperaturen sind mit R100 ein längerer Öffnungsverzug und eine geringere Einspritzmenge festzustellen. Um diesen Einfluss bei der Einspritzstrategie zu kompensieren, ist die Kenntnis der Kraftstofftemperatur im Injektor notwendig. Eine weitere Herausforderung stellt die Gemischaufbereitung dar, hier führen unter anderem die höhere Viskosität und höhere Siedetemperaturen von R100 zu einem schmäleren Spritzwinkel und verzögerter Verdampfung im Vergleich zum Dieselkraftstoff. Eine Erhöhung des Einspritzdrucks und höhere Temperaturen und Drücke in der Brennkammer verbessern die Gemischaufbereitung. Bei Bedingungen von mittlerer und hoher Last ist der Zündverzug von R100 kürzer und das Verbrennungsverhalten ähnlich zum Dieselkraftstoff. Eine geringere Wärmefreisetzung von R100 wird durch den geringeren Heizwert verursacht. Unter Bedingungen von niedriger Last und Motorstart ist ein längerer Zündverzug von R100 im Vergleich zum Dieselkraftstoff festzustellen. Eine Steigerung des Einspritzdrucks und höhere Brennkammerdrücke und -temperaturen führen bei beiden Kraftstoffen zu kürzeren Zündverzügen, der Einfluss dieser Parameter ist jedoch für R100 stärker als für Dieselkraftstoff. Voreinspritzungen führen bei beiden Kraftstoffen zu einer Verkürzung des Zündverzugs der Haupteinspritzung und zu einer geringeren Wärmefreisetzungsrate. Am Motorprüfstand ist bei gleicher Motorapplikation mit R100 eine geringere Leistung als mit Dieselkraftstoff festzustellen. Nach Angleichung der Motorleistung durch Anhebung der Einspritzmenge von R100 sind im Rohabgas Stickstoffoxid (NOX)- und Kohlenstoffmonoxidemissionen auf gleichem Niveau zu Dieselkraftstoff zu beobachten sowie geringere Partikelemissionen. Unter Verwendung eines DoE Vorgehens kann der Partikel-NOX - trade-off von R100 optimiert und Einstellparameter gefunden werden, in denen sowohl niedrigere NOX als auch niedrigere Partikelemissionen im Vergleich zum Dieselkraftstoff resultieren. Das installierte Abgasnachbehandlungssystem, bestehend aus einem Dieseloxidationskatalysator (DOC), Dieselpartikelfilter (DPF) und selektivem katalytischem Reduktionssystem (SCR), arbeitet für beide Kraftstoffe ähnlich und es scheint keine Anpassung der Dosierungsstrategie der wässrigen Harnstofflösung notwendig zu sein. Eine Regeneration des Partikelfilters mit R100 war nach Optimierung der Einstellparameter der Drosselklappe möglich. Motorkaltstart und Leerlauf sind herausfordernde Betriebsphasen, die für R100 einer weiteren Optimierung bedürfen. Eine Temperierung von R100 im Injektor auf 50–60 °C sowie eine Kompensation der Einspritzmenge in Abhängigkeit von der Kraftstofftemperatur sind mögliche Verbesserungsmaßnahmen. Zudem kann durch einen früheren Einspritzbeginn von R100 das Verbrennungsverhalten angepasst werden. Die Motorprüfstandsuntersuchungen bestätigen qualitativ die Erkenntnisse die mit dem hydraulischen Druckanstiegsanalysator (HDA), der Hochdruck-Hochtemperatur-Kammer (HDHT-Kammer) und der Konstantvolumenbrennkammer gewonnen wurden. Weitere Untersuchungen sind notwendig, um die Ergebnisse auf einen baugleichen, in einer mobilen Arbeitsmaschine eingebauten Motor zu transferieren, damit Informationen zur Dauerhaltbarkeit unter realen Bedingungen erhalten werden können. Weiterführende Forschungsarbeiten sind im Bereich der Betriebsphasen des Motorkaltstarts und Leerlaufs mit Rapsölkraftstoff nötig, um einen dauerhaft störungsfreien Betrieb in diesen Betriebsphasen zu erreichen. Die erzielten Erkenntnisse deuten darauf hin, dass hier noch viel Verbesserungspotenzial vorhanden ist. KW - Biokraftstoff KW - Brennwert KW - Zündung KW - Motor KW - Rapsöl KW - Motorsteuerung Y1 - 2020 UR - https://www.tfz.bayern.de/mam/cms08/biokraftstoffe/dateien/tfz_bericht_69_evolum_a.pdf SN - 1614-1008 VL - 69 PB - Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe CY - Straubing ER - TY - GEN A1 - Oetjen, Arne A1 - Rieger, Anna A1 - Rabl, Hans-Peter A1 - van de Par, Steven T1 - The role of dissonance in the sound quality perception for electric vehicles T2 - The Journal of the Acoustical Society of America N2 - Tonal components can be regarded as one of the most relevant components for interior sound quality of electric vehicles, especially at low speeds. Sources for these tones are for example the vehicles' drivetrains but also other technical components. Depending on the driving conditions, due to the interaction of various dominant sources, audible tone complexes can occur. Similar to musical intervals, the different frequency ratios within these complexes can result in consonant or dissonant sensations. The strength of this sensation does not only depend on the frequency relation of the tones but also on their relative levels. In this study, different musical intervals were subjectively rated in terms of their specific consonant or dissonant character. Using an adaptive procedure, sound pairs, each consisting of a two-tone signal, where adjusted to equal dissonance by varying the level of the second tone of one of the two-tone signals. Using the same paradigm, also pairs of equal vehicle sound quality were obtained. With these results, it is possible to quantify dissonance, and theinfluence of dissonance on sound quality expressed in terms of level differences of two-tone signals. These results can help to make the concept of dissonance more useful for sound-engineering applications. Y1 - 2020 U6 - https://doi.org/10.1121/1.5147356 VL - 148 IS - 4 PB - Acoustical Society of America ER - TY - CHAP A1 - Walter, Stefanie A1 - Schwanzer, Peter A1 - Hagen, Gunter A1 - Haft, Gerhard A1 - Dietrich, Markus A1 - Rabl, Hans-Peter A1 - Moos, Ralf ED - Tille, Thomas T1 - Hochfrequenzsensorik zur direkten Beladungserkennung von Benzinpartikelfiltern T2 - Automobil-Sensorik 3 N2 - In Folge der Verschärfung der gesetzlichen Abgasnormen wurden für direkt-einspritzende Benzinmotoren Partikelfilter notwendig. Zur Beladungsüberwachung können aufgrund stark unterschiedlicher Rahmenbedingungen die aus Dieselmotoren bekannten Systeme, wie dem Differenzdrucksensor, nur eingeschränkt übernommen werden. Ein hochfrequenzbasiertes Verfahren koppelt mittels Antennen elektromagnetische Wellen in das Filtergehäuse ein, deren Ausbreitungsverhalten durch die dielektrischen Eigenschaften des eingelagerten Rußes beeinflusst wird. Hierdurch kann bei Auswertung von Transmissionsdämpfung oder Resonanzfrequenzen die Rußbeladung direkt detektiert werden. Y1 - 2020 SN - 978-3-662-61259-0 U6 - https://doi.org/10.1007/978-3-662-61260-6_7 SP - 185 EP - 208 PB - Springer Vieweg CY - Berlin ER - TY - GEN A1 - Schwanzer, Peter A1 - Mieslinger, Johann A1 - Rabl, Hans-Peter A1 - Dietrich, Markus A1 - Haft, Gerhard A1 - Walter, Stefanie A1 - Hagen, Gunter A1 - Moos, Ralf A1 - Gaderer, Matthias T1 - Monitoring of a Particulate Filter for Gasoline Direct Injection Engines with a Radio-Frequency-Sensor T2 - 11th International Exhaust Gas and Particulate Emissions Forum, 3.-4.3.2020, Ludwigsburg, Germany N2 - In order to comply with future emission regulations, the use of particulate filters in vehicles with direct injection gasoline engines is essential. The current amount of soot and ash in the filter is calculated by a soot load model in the electronic control unit in combination with a differential pressure sensor determining the pressure drop over the particulate filter. Active regeneration is initiated if the calculated amount of soot or the measured differential pressure is too high. This is associated with additional fuel consumption. An on-board diagnosis for the particulate filter is currently not part of the Euro 6d emission standard. For future exhaust emission standards, on-board diagnosis or active monitoring of the particulate filter is conceivable. One of the benefits of monitoring is the fact that unnecessary active regenerations can be avoided. As a result, there is no additional fuel consumption due to misinterpretations of the amount of soot in the filter. For active monitoring of the particulate filter, a radiofrequency (RF-) sensor, that detects the soot loading of the filter with electromagnetic waves directly, can be used. Such a system has the advantage that by utilizing the filter as a sensor more precise information about the current state of the filter, e.g. a possible damage, can be provided. Worst-case considerations of filter damages, tested at an engine test bench show the advantages which are entailed by a system like that. By means of partial regeneration of the particulate filter it is demonstrated how the remaining amount of soot in the filter can be detected in a better way in comparison to the differential pressure sensor by using the RF-sensor. Y1 - 2020 UR - https://eref.uni-bayreuth.de/54655/ N1 - Projekttitel: Load Sensor for GPF; Projekt-ID: AZ-1288-17 ER - TY - JOUR A1 - Briem, Ulrich T1 - Die neue VDI 2500 : Faserseilwissen kompakt JF - Logistik für Unternehmen N2 - Die Richtlinie VDI 2500 „Faserseile“ hat 1990 erstmals zusammenfassend den Stand der Technik auf dem Gebiet der Faserseile dargestellt und wertvolle Infor-mationen über Aufbau, Auswahl, Konfek-tionierung und Überwachung von Faser-seilen gegeben. Die jetzt erscheinende zweite Auflage enthält eine Vielzahl wichtiger technischer Neuerungen für die Praxis. Zu nennen sind hier die hochfesten Fasern und deren Beschichtung sowie die erstmals systematisch aufgeführten Sei-lendverbindungen und ein Ausblick auf die zukünftig bedeutsamen sogenannten Hybridseile. Eine Checkliste hilft bei der richtigen Auswahl und Bemessung von Faserseilen. Bei den Normen wurde – soweit möglich – auf europäische Normen verwiesen. Y1 - 2020 UR - https://elibrary.vdi-verlag.de/10.37544/0930-7834-2020-11-12-36/faserseilwissen-kompakt-jahrgang-34-2020-heft-11-12?page=1 IS - 11-12 SP - 36 EP - 37 ER - TY - JOUR A1 - Briem, Ulrich T1 - Umlaufbiegewechselzahl von verdichteten Seildrähten JF - Draht Y1 - 2020 UR - https://umformtechnik.net/draht/Inhalte/Aus-der-Forschung/Umlaufbiegewechselzahl-von-verdichteten-Seildraehten IS - 6 SP - 14 EP - 15 ER - TY - JOUR A1 - Wein, Simon A1 - Tomé, Ana Maria A1 - Goldhacker, Markus A1 - Greenlee, Mark W. A1 - Lang, Elmar Wolfgang T1 - A Constrained ICA-EMD Model for Group Level fMRI Analysis JF - Frontiers in Neuroscience N2 - Independent component analysis (ICA), being a data-driven method, has been shown to be a powerful tool for functional magnetic resonance imaging (fMRI) data analysis. One drawback of this multivariate approach is that it is not, in general, compatible with the analysis of group data. Various techniques have been proposed to overcome this limitation of ICA. In this paper, a novel ICA-based workflow for extracting resting-state networks from fMRI group studies is proposed. An empirical mode decomposition (EMD) is used, in a data-driven manner, to generate reference signals that can be incorporated into a constrained version of ICA (cICA), thereby eliminating the inherent ambiguities of ICA. The results of the proposed workflow are then compared to those obtained by a widely used group ICA approach for fMRI analysis. In this study, we demonstrate that intrinsic modes, extracted by EMD, are suitable to serve as references for cICA. This approach yields typical resting-state patterns that are consistent over subjects. By introducing these reference signals into the ICA, our processing pipeline yields comparable activity patterns across subjects in a mathematically transparent manner. Our approach provides a user-friendly tool to adjust the trade-off between a high similarity across subjects and preserving individual subject features of the independent components. Y1 - 2020 U6 - https://doi.org/10.3389/fnins.2020.00221 SN - 1662-453X SN - 1662-4548 VL - 14 SP - 1 EP - 10 PB - frontiers ER - TY - JOUR A1 - Geilfuß, Kristina A1 - Dawoud, Belal T1 - Analytical investigation of a zeolite-NaY-water adsorption heat and cold storage and its integration into a steam power process JF - Energy N2 - tabilizing the effects of greenhouse gas emissions on the atmosphere is a key step towards solving the global climate change problems. Storage technologies play an essential role in compensating the discrepancy between surplus energy and peak times. Sorption processes, in particular, offer an environment friendly way for almost loss-free heat (of adsorption or absorption) and cold storage. This work is dedicated first to analytically investigate the potential of applying NaY-Water/Zeolite as a working pair for heat and cold storage upon utilizing high temperature heat. It turned out that, the mass of the adsorber heat exchanger increases the useful specific heat stored from 229 kWh/tzeolite for the ideal storage to 538 kWh/tzeolite or even higher depending on the thermal capacity of the adsorber heat exchanger (AdsHX). Contrary to that trend, COP will decrease with increasing the thermal capacity of the AdsHX. Sensible heat losses between charging and discharging phases do have a negative effect on both stored heating capacity and COP. In addition, an innovative hybrid steam power cum adsorption storage process is introduced and analytically investigated at different ambient conditions and time scenarios for on-peak and off-peak durations over the day. The introduced hybrid process seems quite promising in achieving electrical power production and efficiency enhancements during peak load durations. The extent of enhancing both performance indicators increases with increasing the ambient temperature difference between peak and off-peak times. Y1 - 2020 U6 - https://doi.org/10.1016/j.energy.2020.116977 VL - 195 IS - March PB - Elsevier ER - TY - JOUR A1 - Anders, M. A1 - Briem, Ulrich A1 - Novak, G. A1 - Steinbach, G. T1 - Inspektionsintervalle im Blick JF - Technische Logistik Y1 - 2020 SP - 14 EP - 17 PB - Huss-Medien CY - Berlin ER - TY - JOUR A1 - Walter, Stefanie A1 - Schwanzer, Peter A1 - Hagen, Gunter A1 - Haft, Gerhard A1 - Rabl, Hans-Peter A1 - Dietrich, Markus A1 - Moos, Ralf T1 - Modelling the Influence of Different Soot Types on the Radio-Frequency-Based Load Detection of Gasoline Particulate Filters JF - Sensors N2 - Gasoline particulate filters (GPFs) are an appropriate means to meet today's emission standards. As for diesel applications, GPFs can be monitored via differential pressure sensors or using a radio-frequency approach (RF sensor). Due to largely differing soot properties and engine operating modes of gasoline compared to diesel engines (e.g., the possibility of incomplete regenerations), the behavior of both sensor systems must be investigated in detail. For this purpose, extensive measurements on engine test benches are usually required. To simplify the sensor development, a simulation model was developed using COMSOL Multiphysics((R)) that not only allowed for calculating the loading and regeneration process of GPFs under different engine operating conditions but also determined the impact on both sensor systems. To simulate the regeneration behavior of gasoline soot accurately, an oxidation model was developed. To identify the influence of different engine operating points on the sensor behavior, various samples generated at an engine test bench were examined regarding their kinetic parameters using thermogravimetric analysis. Thus, this compared the accuracy of soot mass determination using the RF sensor with the differential pressure method. By simulating a typical driving condition with incomplete regenerations, the effects of the soot kinetics on sensor accuracy was demonstrated exemplarily. Thereby, the RF sensor showed an overall smaller mass determination error, as well as a lower dependence on the soot kinetics. KW - diesel particulate filter (DPF) KW - EMISSIONS KW - finite element method (FEM) KW - FLOW KW - gasoline particulate filter (GPF) KW - PRESSURE-DROP KW - radio frequency (RF) KW - REGENERATION KW - soot mass determination KW - STORAGE Y1 - 2020 U6 - https://doi.org/10.3390/s20092659 VL - 20 IS - 9 SP - 1 EP - 19 PB - MDPI ER - TY - JOUR A1 - Brock, Damian A1 - Koder, Alexander A1 - Rabl, Hans-Peter A1 - Touraud, Didier A1 - Kunz, Werner T1 - Optimising the biodiesel production process: Implementation of glycerol derivatives into biofuel formulations and their potential to form hydrofuels JF - Fuel N2 - A new biofuel concept is developed, enabling the usage of vegetable oils and glycerol derivatives in mixtures with biodiesel. This concept significantly enhances the biodiesel production's profitability and thus strongly contributes to the sustainability of future biofuels. After simple addition reactions with building block chemicals, less hydrophilic glycerol derivatives are obtained, which are compatible with biofuels. Even more, the products of the reactions of glycerol with acetone or butyric acid, referred to as solketal and tributyrin, respectively, lead to promising biofuels in mixtures with rapeseed oil and its biodiesel. Due to their low freezing points, they act as cloud and freezing point depressants, when added to vegetable oil/biodiesel blends. Further, since their viscosity is close to common biodiesel, biofuels containing high amounts of vegetable oil and even more glycerol derivatives than they arise during the biodiesel production can be obtained. Thus, this new class of biofuels enables adaptable compositions depending on the application and also the usage as drop-in fuel without any or just few percent of further additives. After optimising the formulations, ignition delay, exhaust gas recirculation, fuel consumption and combustion process measurements were performed in an unmodified upto-date diesel engine. The experiments showed that the properties of the formulated biofuels are either similar to or even better than diesel. The hydrotropy of the glycerol derivatives in these mixtures enables the potential to implement water into biofuels, so-called hydrofuels, reducing nitrogen oxide emissions and leading to further optimised dropin fuels. Y1 - 2020 U6 - https://doi.org/10.1016/j.fuel.2019.116695 VL - 264 IS - March PB - Elsevier ER - TY - JOUR A1 - Weber, Felix A1 - Huber, Peter A1 - Borchsenius, Fredrik A1 - Braun, Christian T1 - Performance of TMDI for Tall Building Damping JF - Actuators N2 - This study investigates the vibration reduction of tall wind-excited buildings using a tuned mass damper (TMD) with an inerter (TMDI). The performance of the TMDI is computed as a function of the floor to which the inerter is grounded as this parameter strongly influences the vibration reduction of the building and for the case when the inerter is grounded to the earth whereby the absolute acceleration of the corresponding inerter terminal is zero. Simulations are made for broadband and harmonic excitations of the first three bending modes, and the conventional TMD is used as a benchmark. It is found that the inerter performs best when grounded to the earth because, then, the inerter force is in proportion to the absolute acceleration of only the pendulum mass, but not to the relative acceleration of the two inerter terminals, which is demonstrated by the mass matrix. However, if the inerter is grounded to a floor below the pendulum mass, the TMDI only outperforms the TMD if the inerter is grounded to a floor within approximately the first third of the building’s height. For the most realistic case, where the inerter is grounded to a floor in the vicinity of the pendulum mass, the TMDI performs far worse than the classical TMD. KW - damping KW - inerter KW - simulation KW - tall building KW - TMD KW - TMDI KW - wind excitation Y1 - 2020 U6 - https://doi.org/10.3390/act9040139 VL - 9 IS - 4 SP - 1 EP - 13 PB - MPDI ER - TY - JOUR A1 - Frazzica, Andrea A1 - Brancato, Vincenza A1 - Dawoud, Belal T1 - Unified Methodology to Identify the Potential Application of Seasonal Sorption Storage Technology JF - Energies N2 - In this study, the definition of a new methodology for a preliminary evaluation of the working boundary conditions under which a seasonal thermal energy storage (STES) system operates is described. The approach starts by considering the building features as well as the reference heating system in terms of solar thermal collectors’ technology, ambient heat sinks/source, and space heating distribution systems employed. Furthermore, it is based on a deep climatic analysis of the place where the STES needs to be installed, to identify both winter and summer operating conditions. In particular, the STES energy density is evaluated considering different space heating demands covered by the STES (ranging from 10% up to 60%). The obtained results demonstrate that this approach allows for the careful estimation of the achievable STES density, which is varies significantly both with the space heating coverage guaranteed by the STES as well as with the ambient heat source/sink that is employed in the system. This confirms the need for careful preliminary analysis to avoid the overestimation of the STES material volume. The proposed approach was then applied for different climatic conditions (e.g., Germany and Sweden) and the volume of one of the most attractive composite sorbent materials reported in the literature, i.e., multi-wall carbon nanotubes (MWCNT)-LiCl, using water as the working fluid, needed for covering the variable space heating demand in a Nearly Zero Energy Building (NZEB) was calculated. In the case of Swedish buildings, it ranges from about 3.5 m3 when 10% of the space heating demand is provided by the STES, up to 11.1 m3 when 30% of the space heating demand is provided by the STES. KW - seasonal thermal storage KW - composite sorbents KW - operating conditions Y1 - 2020 U6 - https://doi.org/10.3390/en13051037 VL - 13 IS - 5 SP - 1 EP - 17 PB - MPDI CY - Basel ER - TY - JOUR A1 - Chatzitakis, Paris A1 - Safarov, Javid A1 - Opferkuch, Frank A1 - Dawoud, Belal A1 - Hassel, Egon T1 - Vapor pressures and activity coefficients of 2,2,2-trifluoroethanol in binary mixtures with 1,3-dimethyl-2-imidazolidinone and 2-pyrrolidone JF - Journal of Molecular Liquids N2 - The vapor pressures of two binary mixtures containing 2-trifluoroethanol (TFE) + 1,3-dimethyl-2-imidazolidinone (DMI) and TFE + 2-pyrrolidone (PYR), were investigated at temperatures T = (274.15 to 423.15) K using two different static method installations. Both combinations were modelled using an extended Clausius-Clapeyron equation with concentration dependent parameters and the NRTL equation with temperature dependent parameters. The best fit was obtained using the NRTL equation. KW - 2-Trifluoroethanol KW - 1,3-Dimethyl-2-imidazolidinone KW - 2-Pyrrolidone KW - Vapor pressure KW - NRTL KW - Clausius-Clapeyron Y1 - 2020 U6 - https://doi.org/10.1016/j.molliq.2020.112828 SN - 0167-7322 VL - 305 IS - May PB - Elsevier ER - TY - PAT A1 - Olbrich, Florian A1 - Pongratz, Christian A1 - Bierl, Rudolf A1 - Ehrlich, Ingo T1 - Method and System for Evaluating a Structural Integrity of an Aerial Vehicle T2 - Europäisches Patentblatt (09.12.2020) zur Anmeldung: OTH Regensburg, Anmeldenummer: 19179054.2, Patentnummer 1001/3748327, Veröffentlichungsnummer: 3 748 327 Y1 - 2020 SP - 395 EP - 396 ER - TY - JOUR A1 - Geith, Markus A. A1 - Eckmann, Jakob D. A1 - Haspinger, Daniel Ch. A1 - Agrafiotis, Emmanouil A1 - Maier, Dominik A1 - Szabo, Patrick A1 - Sommer, Gerhard A1 - Schratzenstaller, Thomas A1 - Holzapfel, Gerhard A. T1 - Experimental and mathematical characterization of coronary polyamide-12 balloon catheter membranes JF - PLoS One N2 - The experimental quantification and modeling of the multiaxial mechanical response of polymer membranes of coronary balloon catheters have not yet been carried out. Due to the lack of insights, it is not shown whether isotropic material models can describe the material response of balloon catheter membranes expanded with nominal or higher, supra-nominal pressures. Therefore, for the first time, specimens of commercial polyamide-12 balloon catheters membranes were investigated during uniaxial and biaxial loading scenarios. Furthermore, the influence of kinematic effects on the material response was observed by comparing results from quasi-static and dynamic biaxial extension tests. Novel clamping techniques are described, which allow to test even tiny specimens taken from the balloon membranes. The results of this study reveal the semi-compliant, nonlinear, and viscoelastic character of polyamide-12 balloon catheter membranes. Above nominal pressure, the membranes show a pronounced anisotropic mechanical behavior with a stiffer response in the circumferential direction. The anisotropic feature intensifies with an increasing strain-rate. A modified polynomial model was applied to represent the realistic mechanical response of the balloon catheter membranes during dynamic biaxial extension tests. This study also includes a compact set of constitutive model parameters for the use of the proposed model in future finite element analyses to perform more accurate simulations of expanding balloon catheters. KW - Catheters KW - Anisotropy KW - Polymers KW - Viscoelasticity KW - Coronary stenting KW - Finite element analysis KW - Deformation KW - Adhesives Y1 - 2020 U6 - https://doi.org/10.1371/journal.pone.0234340 VL - 15 IS - 6 SP - 1 EP - 22 PB - PLOS ER - TY - CHAP A1 - Auer, Simon A1 - Kubowitsch, Simone A1 - Krutsch, Werner A1 - Renkawitz, Tobias A1 - Süß, Franz A1 - Dendorfer, Sebastian T1 - Effect of mental demand on knee forces in professional youth soccer players T2 - ISBS Proceedings Archive N2 - Soccer is one of the most popular sports all around the world. It is an injurious type of sport with a focus on lower extremities and high psychological pressure during matches. The stressor is linked with injuries and an increased musculoskeletal loading. This study investigates the influence of cognitive stress on the load profile of the knee joint. Twelve professional youth soccer players performed highly dynamic runs with and without additional cognitive stress. The runs were analysed with a musculoskeletal simulation software. The data analysis shows no difference in knee joint reaction loading under additional mental stress compared to the baseline. Yet running times are significantly lower in the baseline. While there is no increase in the joint loads, the running times indicate an altered movement behaviour when the subjects are exposed to additional mental demand. KW - Kniegelenk KW - Körperliche Belastung KW - Stress KW - Computersimulation Y1 - 2020 UR - https://commons.nmu.edu/isbs/vol38/iss1/28 VL - 38 IS - 1, Art. 28 ER - TY - JOUR A1 - Aurbach, Maximilian A1 - Špička, Jan A1 - Süß, Franz A1 - Vychytil, J. A1 - Havelková, Leonard A1 - Ryba, T. A1 - Dendorfer, Sebastian T1 - Torus obstacle method as a wrapping approach of the deltoid muscle group for humeral abduction in musculoskeletal simulation JF - Journal of Biomechanics N2 - Musculoskeletal models of the shoulder complex are valuable research aids to investigate tears of the supraspinatus and the resulting mechanical impact during abduction of the humerus. One of the major contributors to this motion is the deltoid muscle group and for this, an accurate modeling of the lines of action is indispensable. The aim of this work was to utilize a torus obstacle wrapping approach for the deltoids of an existing shoulder model and assess the feasibility of the approach during humeral abduction. The shoulder model from the AnyBody™ modeling system was used as a platform. The size of the tori is based on a magnetic resonance imaging (MRI) approach and several kinematic couplings are implemented to determine the trajectories of the tori during abduction. To assess the model behavior, the moment arms of the virtual muscle elements and the resultant glenohumeral joint reaction force (GHJF) were compared with reference data from the literature during abduction of the humerus in the range 20°–120°. The root mean square error for the anterior, lateral and posterior part between the simulated muscle elements and reference data from the literature was 3.9, 1.7 and 5.8 mm, respectively. The largest deviation occurred on the outer elements of the muscle groups, with 12.6, 10.4 and 20.5 mm, respectively. During abduction, there is no overlapping of the muscle elements and these are in continuous contact with the torus obstacles, thus enabling a continuous force transmission. This results in a rising trend of the resultant GHJF. The torus obstacle approach as a wrapping method for the deltoid muscles provides a guided muscle pathing by simultaneously approximating the curvature of the deltoid muscle. The results from the comparison of the simulated moment arms and the resultant GHJF are in accordance with those in the literature in the range 20°–120° of abduction. Although this study shows the strength of the torus obstacle as a wrapping approach, the method of fitting the tori according to MRI data was not suitable. A cadaver study is recommended to better validate and mathematically describe the torus approach. KW - Muscoloskeletal model KW - AnyBody Modeling System KW - MRI KW - Shoulder joint complex KW - Muscle trajectory KW - Torus KW - Wrapping Y1 - 2020 U6 - https://doi.org/10.1016/j.jbiomech.2020.109864 VL - 109 IS - August PB - Elsevier ER - TY - JOUR A1 - Aurbach, Maximilian A1 - Spicka, Jan A1 - Süß, Franz A1 - Dendorfer, Sebastian T1 - Evaluation of musculoskeletal modelling parameters of the shoulder complex during humeral abduction above 90° JF - Journal of Biomechanics N2 - Based on electromyographic data and force measurements within the shoulder joint, there is an indication that muscle and resulting joint reaction forces keep increasing over an abduction angle of 90°. In inverse dynamics models, no single parameter could be attributed to simulate this force behaviour accordingly. The aim of this work is to implement kinematic, kinetic and muscle model modifications to an existing model of the shoulder (AnyBody™) and assess their single and combined effects during abduction up to 140° humeral elevation. The kinematics and the EMG activity of 10 test subjects were measured during humeral abduction. Six modifications were implemented in the model: alternative wrapping of the virtual deltoid muscle elements, utilization of a three element Hill model, strength scaling, motion capture driven clavicle elevation/protraction, translation of the GH joint in dependency of the acting forces and an alteration of the scapula/clavicle rhythm. From the six modifications, 16 different combinations were considered. Parameter combinations with the Hill model changed the resultant GH joint reaction force and led to an increase in force during abduction of the humerus above 90°. Under the premise of muscle activities and forces within the GH joint rising after 90° of humeral abduction, we propose that the Hill type muscle model is a crucial parameter for accurately modelling the shoulder. Furthermore, the outcome of this study indicates that the Hill model induces the co-contraction of the muscles of the shoulder without the need of an additional stability criterion for an inverse dynamics approach. KW - Shoulder joint KW - Musculoskeletal modelling KW - EMG KW - Glenohumeral joint reaction force KW - Muscle model KW - Schultergelenk KW - Bewegungsapparat KW - Biomechanik KW - Simulation Y1 - 2020 U6 - https://doi.org/10.1016/j.jbiomech.2020.109817 VL - 106 IS - June PB - Elsevier ER - TY - VIDEO A1 - Auer, Simon A1 - Reinker, Lukas A1 - Süß, Franz A1 - Kubowitsch, Simone A1 - Krutsch, Werner A1 - Weber, Markus A1 - Renkawitz, Tobias A1 - Dendorfer, Sebastian T1 - Webcast: Effect of mental demand on leg loading in highly dynamic motion N2 - Football players have a high risk of leg muscle injuries, especially when exposed to mental stress. Injuries to muscles of the thigh are common in amateur and professional football, representing almost a third of all injuries. These injuries occur primarily in non-contact situations and from overuse. They can lead to a range of costs, including financial costs associated with treatment as well as those associated with long-term recovery, and absence from training and/or competition. Further, there is a high risk of injury recurrence and subsequent injury. KW - Webcast KW - AnyBody KW - Stress KW - Football KW - Speedcourt Y1 - 2020 UR - https://www.youtube.com/watch?v=uSc_9XlnkaA ER - TY - VIDEO A1 - Melzner, Maximilian A1 - Engelhardt, Lucas T1 - AnyBody Webcast - A new musculoskeletal AnyBody™ detailed hand model Y1 - 2020 UR - https://www.youtube.com/watch?v=E4xnbjRJYm8&t=631s ER - TY - CHAP A1 - Xue, Lufeng A1 - Paredes, Marcelo A1 - Nonn, Aida A1 - Wierzbicki, Tomasz T1 - Modeling of Crack Propagation in Defective X100 Line Pipes T2 - ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering: August 3-7, 2020, virtual, online N2 - A comprehensive experimental program is carried out to determine material parameters for fracture initiation and propagation in X100 pipeline steels. The quadratic Hill’48 yield function along with an isotropic hardening are used to describe plastic flow at large deformation and a phenomenological fracture criterion to predict fracture initiation. Fracture mechanics SENT specimens are used to calibrate post-initiation softening parameters necessary for ductile crack propagation in thick components. Once the material model parameters set is complete a final comparison is conducted with ring expansion test on same material. KW - Berg KW - Bruchmechanik KW - Pipeline KW - plastisches Fließen KW - Rissausbreitung KW - Versuchsprogramm KW - Werkstoffmodell KW - Werkstoffparameter Y1 - 2020 SN - 978-0-7918-8434-8 U6 - https://doi.org/10.1115/OMAE2020-18048 PB - American Society of Mechanical Engineers CY - New York ER - TY - CHAP A1 - Rieger, Anna A1 - Mühlbauer, Christian A1 - Rabl, Hans-Peter A1 - Weber, Rainer T1 - Dissonanz als Bewertungskriterium multi-tonalen Schalls T2 - Fortschritte der Akustik - DAGA 2020: 46. Deutsche Jahrestagung für Akustik Y1 - 2020 UR - https://www.dega-akustik.de/publikationen/online-proceedings/ SP - 788 EP - 791 PB - Deutsche Gesellschaft für Akustik e.V. ER - TY - CHAP A1 - Mühlbauer, Christian A1 - Rabl, Hans-Peter A1 - Rottengruber, Herrmann ED - Siebenpfeiffer, Wolfgang T1 - Development of a Methodology for Acoustic Analysis and Optimization of Mechatronic Fuel Injection Systems T2 - Automotive Acoustics Conference 2019: Proceedings, 5. Internationale ATZ-Fachtagung Fahrzeugakustik N2 - To identify the sound quality of fuel injection systems as a frontloading measure, a system test bench has been developed that simulates the structure and airborne noise emission. The setup of the system test bench includes an assembly of the acoustical relevant engine parts and an encapsulated drive for the high-pressure pump. A specific control unit enables a high variability for the operation strategy of the injection system. The focus of this study is on the development of a methodology to analyze and optimize the sound quality of gasoline direct injectors in critical operation points by suitable active means. For this, the injection parameters in engine idle have been identified and subsequently transferred to the system test bench. Additionally, the injection parameters have been optimized acoustically and the impacts on the key functions regarding injection rating and shot-to-shot scattering of the injected fuel mass are discussed. Y1 - 2020 SN - 978-3-658-27668-3 U6 - https://doi.org/10.1007/978-3-658-27669-0_15 SP - 211 EP - 225 PB - Springer Vieweg CY - Wiesbaden ER - TY - CHAP A1 - Höcherl, Johannes A1 - Adam, Andreas A1 - Schlegl, Thomas A1 - Wrede, Britta T1 - Human-Robot Assembly: Methodical Design and Assessment of an Immersive Virtual Environment for Real-World Significance T2 - 2020 25th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA): 8-11 Sept. 2020, Vienna, Austria N2 - Virtual reality is a powerful tool for industrial applications. The article at hand addresses designers of industrial virtual environments. It summarizes key aspects to design immersive and coherent virtual environments. Furthermore, relevant influencing factors for a high quality virtual environment and tools to quantify this quality are presented. So far, a methodology to design, evaluate, and transfer knowledge from virtual environments into reality has been missing and is of high value for industrial applications. The proposed methodical approach includes the steps application analysis, technology selection and integration, design of virtual environment, evaluation of simulator quality, as well as discussion of the real-world validity. The method is shown on the example of a virtual human-robot working cell used to analyze the human perception of robot behavior during mutual assembly processes. The quality of the virtual environment is evaluated to be adequate for those purposes and the transfer of knowledge gained in virtuality on a corresponding real-world application is discussed. To the best of our knowing a system like the presented one, including full-body tracking, finger tracking, a virtual avatar and a head-mounted display has not been used for industrial use cases and human-robot cooperation before. KW - assembly KW - Avatars KW - coherent virtual environment KW - Conferences KW - Design methodology KW - fidelity KW - Head-mounted displays KW - human-robot cooperation KW - immersive KW - industrial applications KW - Knowledge transfer KW - Manufacturing automation KW - real-world validity KW - Robots KW - simulator quality KW - system design KW - virtual environments KW - Virtual reality Y1 - 2020 U6 - https://doi.org/10.1109/ETFA46521.2020.9212039 SP - 549 EP - 556 PB - IEEE ER - TY - CHAP A1 - Wostmann, Rene A1 - Schlunder, Philipp A1 - Temme, Fabian A1 - Klinkenberg, Ralf A1 - Kimberger, Josef A1 - Spichtinger, Andrea A1 - Goldhacker, Markus A1 - Deuse, Jochen T1 - Conception of a Reference Architecture for Machine Learning in the Process Industry T2 - 2020 IEEE International Conference on Big Data (Big Data): 10.12.2020 - 13.12.2020 Atlanta, GA, USA N2 - The increasing global competition demands continuous optimization of products and processes from companies in the process industry. Where conventional methods of Lean Management and Six Sigma reach their limits, new opportunities and challenges arise through increasing connectivity in the Industrial Internet of Things and machine learning. The majority of industrial projects do not reach the deployment or are isolated solutions, as the structures for data integration, training, deployment and maintenance of models are not established. This paper presents the conception of a reference architecture for machine learning in the process industry to support companies in implementing their own specific structures. The focus is on the development process and an exemplary implementation in the brewing industry. KW - Big data KW - Companies KW - Industrial Internet of Things KW - Industries KW - Machine learning KW - Optimization KW - process industry KW - Production KW - Reference architecture KW - Six sigma KW - Training Y1 - 2020 SN - 978-1-7281-6251-5 U6 - https://doi.org/10.1109/bigdata50022.2020.9378290 SP - 1726 EP - 1735 PB - IEEE ER - TY - CHAP A1 - Anders, M. A1 - Briem, Ulrich A1 - Novak, G. A1 - Steinbach, G. ED - Katterfeld, André ED - Krause, Friedrich ED - Pfeiffer, Dagmar ED - Richter, Klaus T1 - Neue VDI-Richtlinie für die Seiltriebauslegung T2 - 28. Internationale Kranfachtagung 2020 "Kran 4.0: Potenziale der Digitalisierung", 4. und 5. März 2020, Magdeburg Y1 - 2020 SN - 978-3-947068-08-1 SP - 59 EP - 72 PB - LOGiSCH GmbH CY - Magdeburg ER - TY - JOUR A1 - Steininger, Peter A1 - Gaderer, Matthias A1 - Dawoud, Belal A1 - Gaderer, Matthias T1 - Experimental and numerical study on the solar gain and heat loss of typical existing and refurbished German buildings JF - iCRBE Procedia N2 - This communication introduces an experimental setup for investigating the effect of solar radiation on the reduction of transmission heat losses and the steady state thermal conductance of uninsulated and insulated multi-layer wall samples. The setup consists of two adjacent climatic chambers, which share a common wall, in which the multi-layer wall samples are mounted. A solar simulator is applied within the outdoor air climatic chamber, whose radiation spectrum and radiation intensity are approximately equivalent to those of the sun. The first tests have been carried out on a wall sample with a typical structure of existing buildings from the year 1930 in Germany. In addition, a high-performance insulating plaster layer has been applied on a basic test sample (with existing building structure) to replicate and assess the refurbished scenario. Furthermore, a numerical investigation on the transient heat transfer process is carried out by using the simulation software COMSOL Multiphysics®. The experimental results of both uninsulated and insulated wall samples are validated against 1D and 3D models. As seen, the uninsulated wall, whose thermal conductance was experimentally determined to be equal to 1.79 W/(m²K), absorbs a heat flux of 208 W/m² through its external wall surface over a period of 8 hours. A fraction of 9.8 % of the absorbed heat arrives as a gain on the internal wall and reduces the transmission heat losses by 11.7 % over a period of 55 hours. On the other hand, the thermal conductivity of the insulation layer of the refurbished wall sample with micro hollow glass spheres was estimated by a parameter estimation procedure using the 3D model and the obtained experimental data. Using the estimated thermal conductivity, a thermal conductance of 0.42 W/(m²K) has been obtained for the refurbished wall sample. Y1 - 2020 UR - https://www.scilit.net/article/e45ed49630736c2ed82cd848e55bb69c?action=show-references U6 - https://doi.org/10.32438/icrbe.202035 VL - 1 IS - 1 SP - 75 EP - 93 PB - Weentech ER - TY - CHAP A1 - Pohlt, Clemens A1 - Schlegl, Thomas A1 - Wachsmuth, Sven T1 - Weakly-Supervised Learning for Multimodal Human Activity Recognition in Human-Robot Collaboration Scenarios T2 - 2020 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS): October 25-29, 2020, Las Vegas, NV, USA (virtual) N2 - The ability to synchronize expectations among human-robot teams and understand discrepancies between expectations and reality is essential for human-robot collaboration scenarios. To ensure this, human activities and intentions must be interpreted quickly and reliably by the robot using various modalities. In this paper we propose a multimodal recognition system designed to detect physical interactions as well as nonverbal gestures. Existing approaches feature high post-transfer recognition rates which, however, can only be achieved based on well-prepared and large datasets. Unfortunately, the acquisition and preparation of domain-specific samples especially in industrial context is time consuming and expensive. To reduce this effort we introduce a weakly-supervised classification approach. Therefore, we learn a latent representation of the human activities with a variational autoencoder network. Additional modalities and unlabeled samples are incorporated by a scalable product-of-expert sampling approach. The applicability in industrial context is evaluated by two domain-specific collaborative robot datasets. Our results demonstrate, that we can keep the number of labeled samples constant while increasing the network performance by providing additional unprocessed information. KW - Activity recognition KW - Collaboration KW - Intelligent robots KW - reliability KW - Service robots KW - Synchronization Y1 - 2020 U6 - https://doi.org/10.1109/IROS45743.2020.9340788 SP - 8381 EP - 8386 PB - IEEE ER - TY - JOUR A1 - Hüntelmann, Sven A1 - Hierl, Stefan T1 - AM-gerechte Bauteilgestaltung BT - Erarbeitung eines methodischen Vorgehens für die Topologieoptimierung additiv gefertigter Bauteile JF - additive - Das Magazin für generative Fertigung Y1 - 2020 UR - https://additive.industrie.de/forschung/am-gerechte-bauteilgestaltung/#slider-intro-2 IS - 01 SP - 57 ER - TY - BOOK A1 - Galka, Stefan T1 - AutoStore - was Nutzer über das System berichten können BT - Ergebnisse einer Online-Umfrage KW - Kleinteil KW - Lager KW - Intralogistik KW - Umfrage Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-6463 SN - 978-3-9818209-9-7 CY - Regensburg ER - TY - JOUR A1 - Weber, Markus A1 - Merle, Christian A1 - Nawabi, Danyal H. A1 - Dendorfer, Sebastian A1 - Grifka, Joachim A1 - Renkawitz, Tobias T1 - Inaccurate offset restoration in total hip arthroplasty results in reduced range of motion JF - Scientific Reports N2 - Offset restoration in total hip arthroplasty (THA) is associated with postoperative range of motion (ROM) and gait kinematics. We aimed to research into the impact of high offset (HO) and standard stems on postoperative ROM. 121 patients received cementless THA through a minimally-invasive anterolateral approach. A 360° hip ROM analysis software calculated impingement-free hip movement based on postoperative 3D-CTs compared to ROM values necessary for activities of daily living (ADL). The same model was then run a second time after changing the stem geometry between standard and HO configuration with the implants in the same position. HO stems showed higher ROM for all directions between 4.6 and 8.9° (p < 0.001) compared with standard stems but with high interindividual variability. In the subgroup with HO stems for intraoperative offset restoration, the increase in ROM was even higher for all ROM directions with values between 6.1 and 14.4° (p < 0.001) compared to offset underrestoration with standard stems. Avoiding offset underrestoration resulted in a higher amount of patients of over 20% for each ROM direction that fulfilled the criteria for ADL (p < 0.001). In contrast, in patients with standard stems for offset restoration ROM did increase but not clinically relevant by offset overcorrection for all directions between 3.1 and 6.1° (p < 0.001). Offset overcorrection by replacing standard with HO stems improved ROM for ADL in a low number of patients below 10% (p > 0.03). Patient-individual restoration of offset is crucial for free ROM in THA. Both over and underrestoration of offset should be avoided. KW - Adaptive clinical trial KW - Bone imaging Y1 - 2020 U6 - https://doi.org/10.1038/s41598-020-70059-1 VL - 10 IS - 13208 SP - 9 PB - Nature ER - TY - JOUR A1 - Schulz, Carsten A1 - Schwarz, Colin T1 - Drivetrain fatigue strength characteristics of model-predictive control for wind turbines JF - Wind Energy N2 - Wind turbines play a crucial role in the revolution towards renewable resources. They need to be economically competitive to be sustainable. This still requires to lower the cost of energy (COE). To this end, nonlinear model predictive control (NMPC) is used within this paper. As known from literature, NMPC significantly improves the energy extracting performance as well as the mitigation of tower loads of wind turbines. As it is shown in this paper, the drivetrain fatigue strength drops disproportionally in parallel, which either increases the demands on the turbine design or decreases the lifetime of drivetrain components. Without additional boundary conditions to the underlying optimal control problems (OCPs), the application of energy-maximizing NMPC might so even raise the COE. Only penalizing axial torque oscillations by quadratic terms decreases energy-extracting performance below the level of classical wind turbine controllers. This makes more sophisticated conditions necessary. In this paper, the increase of the drivetrain damage by NMPC is analyzed, and appropriate boundary conditions are derived, to balance the two contradicting objectives of energy maximization and drivetrain load mitigation. An NMPC approach based on indirect methods is used, to obtain a solution of the OCPs very efficiently. It applies the Hamilton equations and Pontryagin's maximum principle. Its accuracy and efficiency to solve OCPs was presented over the last decades. Y1 - 2020 U6 - https://doi.org/10.1002/we.2520 VL - 23 IS - 12 SP - 2137 EP - 2149 PB - Wiley ER - TY - GEN A1 - Singh, Max Diamond T1 - Conformity Assessment Procedure MDR BT - [Vortrag gehalten am 24.02.2020] T2 - MDR Training: Person Responsible for Regulatory Compliance Course, 24.-25.02.2020, Tel Aviv, Obelis Academy Y1 - 2020 ER - TY - GEN A1 - Singh, Max Diamond T1 - Notified body feedback: PSUR Forms. Post Market Surveillance & Vigilance BT - [Vortrag gehalten am 24.06.2020] T2 - MedTech Summit 2020: EU MDR & IVDR: the end is in sight, Dublin/virtual, 20.-26.06.2020 Y1 - 2020 ER - TY - GEN A1 - Singh, Max Diamond T1 - MDR - Die neuen rechtlichen Bedingungen für Händler und Hersteller: aus der Sicht einer benannten Stelle T2 - MEGRA Jahrestagung. - Wien, 18.05.2020 [Veranstalter: Mitteleuropäische Gesellschaft für Regulatory Affairs] Y1 - 2020 ER - TY - GEN A1 - Singh, Max Diamond T1 - Innovation challenges for orthopedic device manufacturers under the new EU MDR BT - a notified body perspective T2 - ORS (Orthopaedic Research Society) Annual Meeting. - Phoenix, Arizona, 08. - 11.02.2020 Y1 - 2020 ER - TY - GEN A1 - Singh, Max Diamond T1 - General Overview of the Medical Device Regulation T2 - MDR-Roadshow - TÜV SÜD MHS, India Y1 - 2020 ER - TY - GEN A1 - Singh, Max Diamond T1 - Stakeholder view on Post Market Surveillance under the EU MDR: Timelines, Compliance and Requirements ; Post Market Surveillance & Vigilance BT - [Vortrag gehalten am: 23.6.2020] T2 - MedTech summit 2020: EU MDR & IVDR: the end ist in sight, 22.-26.06.2020, Dublin/virtual Y1 - 2020 ER - TY - GEN A1 - Singh, Max Diamond T1 - Technical Documentation MDR / IVDR, including the Declaration of Conformity BT - [Vortrag gehalten am 24.02.2020] T2 - MDR Training: Person Responsible for Regulatory Compliance, 24.-25.02.2020, Tel Aviv, Obelis Academy Y1 - 2020 ER - TY - GEN A1 - Singh, Max Diamond T1 - Herausforderungen der Medizinprodukteindustrie bei der Internationalisierung T2 - Studienwoche an der HNU (Hochschule Neu-Ulm) 2020 Y1 - 2020 ER - TY - JOUR A1 - Freese, Jens de A1 - Holtmannspötter, Jens A1 - Raschendorfer, Stefan A1 - Hofmann, Timo T1 - End milling of Carbon Fiber Reinforced Plastics as surface pretreatment for adhesive bonding - effect of intralaminar damages and particle residues JF - The Journal of Adhesion N2 - In this study, the use of dry end milling of carbon fiber reinforced plastics (CFRP) as surface pretreatment for high-strength (structural) adhesive bonding was investigated. Surfaces were pretreated using different milling parameters; subsequently, they were adhesively bonded and tested. In comparison with sanding and other industrial standard pretreatment methods, the measured adhesive strength was significantly lower. Detailed surface investigations utilizing field-emission scanning electron microscopy could identify two major effects for lower adhesion strength. Intralaminar damages and microparticle residues on the created surface reduced the strength of the CFRP adhesive joints. This eventually explains results from investigations on milling pretreated repairs. By application of power ultrasound cleaning equipment and coating with low viscosity epoxy primers, the authors showed a way to overcome the discovered drawbacks and to improve bond strength significantly. Surface roughness measurements showed that the arithmetical mean roughness R(a)can be used as an effective value for assessment of mechanical pretreated CFRP surfaces as well as for the quality of necessarily following cleaning processes. KW - aeronautical KW - BONDED JOINTS KW - butt joints KW - composites KW - epoxides KW - Epoxy KW - GRAPHITE/EPOXY COMPOSITE KW - ORTHOGONAL CUTTING MECHANISMS KW - repair KW - surface treatment Y1 - 2020 U6 - https://doi.org/10.1080/00218464.2018.1557054 VL - 96 IS - 12 SP - 1122 EP - 1140 PB - TAYLOR & FRANCIS ER - TY - JOUR A1 - De Pieri, Enrico A1 - Atzori, Federica A1 - Ferguson, Stephen J. A1 - Dendorfer, Sebastian A1 - Leunig, Michael A1 - Aepli, Martin T1 - Contact force path in total hip arthroplasty: effect of cup medialisation in a whole-body simulation JF - HIP International N2 - Background: Cup medialisation down to the true acetabular floor in total hip arthroplasty with a compensatory femoral offset increase seems to be mechanically advantageous for the abductor muscles due to the relocation of the lever arms (body weight lever arm decreased, abductor lever arm increased). However, limited information is currently available about the effects of this reconstruction type at the head cup interface, compared to an anatomical reconstruction that maintains the natural lever arms. Through a whole-body simulation analysis, we compared medialised versus anatomical reconstruction in THA to analyse the effects on: (1) contact force magnitude at the head cup interface; (2) contact force path in the cup; and (3) abductor activity. Methods: Musculoskeletal simulations were performed to calculate the above-mentioned parameters using inverse dynamics analysis. The differences between the virtually implanted THAs were calculated to compare the medialised versus anatomical reconstruction. Results: Cup medialisation with compensatory femoral offset increase led to: (1) a reduction in contact force magnitude at the head cup interface up to 6.6%; (2) a similar contact force path in the cup in terms of sliding distance and aspect ratio; and (3) a reduction in abductor activity up to 17.2% (gluteus medius). Conclusions: In our opinion, these potential biomechanical gains do not generally justify a fully medialised reconstruction, especially in younger patients that are more likely to undergo revision surgery in their lifetime. Cup medialisation should be performed until sufficient press fit and bony coverage of a properly sized and oriented cup can be achieved. KW - Cup medialisation KW - femoral offset KW - hip contact force KW - total hip anthroplasty KW - total hip replacement KW - Hüftgelenkprothese KW - Kontaktkraft KW - Biomechanische Analyse KW - Simulation Y1 - 2020 U6 - https://doi.org/10.1177/1120700020917321 VL - 31 IS - 5 SP - 624 EP - 631 PB - Sage ER - TY - JOUR A1 - Auer, Simon A1 - Kurbowitsch, Simone A1 - Süß, Franz A1 - Renkawitz, Tobias A1 - Krutsch, Werner A1 - Dendorfer, Sebastian T1 - Mental stress reduces performance and changes musculoskeletal loading in football-related movements JF - Science and Medicine in Football N2 - Purpose: Football players have a high risk of leg muscle injuries, especially when exposed to mental stress. Hence, this study investigated the musculoskeletal response of elite youth football players during highly dynamic movements under stress. The hypothesis is that mental stress reduces performance and changes the muscular forces exerted. Materials & methods: Twelve elite youth football players were subjected to mental stress while performing sports-specific change-of-direction movements. A modified version of the d2 attention test was used as stressor. The kinetics are computed using inverse dynamics. Running times and exerted forces of injury-prone muscles were analysed. Results: The stressor runs were rated more mentally demanding by the players (p = 0.006, rs = 0.37) with unchanged physical demand (p = 0.777, rs = 0.45). This resulted in 10% longer running times under stress (p < 0.001, d = −1.62). The musculoskeletal analysis revealed higher peak muscle forces under mental stress for some players but not for others. Discussion: The study shows that motion capture combined with musculoskeletal computation is suitable to analyse the effects of stress on athletes in highly dynamic movements. For the first time in football medicine, our data quantifies an association between mental stress with reduced football players’ performance and changes in muscle force. KW - Biomechanics KW - muscle injury KW - attention KW - musculoskeletal simulation Y1 - 2020 U6 - https://doi.org/10.1080/24733938.2020.1860253 VL - 5 IS - 4 SP - 323 EP - 329 PB - Taylor & Francis ER - TY - GEN A1 - Melzner, Maximilian A1 - Pfeifer, Christian A1 - Alt, V. A1 - Süß, Franz A1 - Dendorfer, Sebastian T1 - Änderung der Gelenkreaktionskraft bei Schädigung des medialen Bandapparates im Ellenbogen T2 - Zeitschrift fur Orthopadie und Unfallchirurgie KW - Muskuloskelettale Simulation KW - Ellenbogenstabilität Y1 - 2020 U6 - https://doi.org/10.1055/s-0040-1717270 N1 - Poster VL - 158 IS - S01 PB - Thieme ER - TY - GEN A1 - Melzner, Maximilian A1 - Engelhardt, Leonard A1 - Süß, Friedrich A1 - Dendorfer, Sebastian T1 - Sensitivity evaluation of a musculoskeletal hand model using Latin hypercube sampling T2 - ESMAC 2020 Abstracts Y1 - 2020 U6 - https://doi.org/10.1016/j.gaitpost.2020.08.008 VL - 81 IS - Suppl. 1 PB - Elsevier ER - TY - GEN A1 - Dendorfer, Sebastian T1 - The influence of mental stress on the musculoskeletal system Y1 - 2020 ER - TY - JOUR A1 - Visscher, Rosa A1 - Wyss, C. A1 - Singh, Navrag B. A1 - Taylor, William R. A1 - Dendorfer, Sebastian A1 - Rutz, E. A1 - Brunner, Reinald T1 - Influence of TAL-TATS surgery on energy production of Tricepts Surae - A musculoskeletal modeling evaluation JF - Gait & Posture Y1 - 2020 U6 - https://doi.org/10.1016/j.gaitpost.2020.08.090 VL - 81 IS - Suppl. 1 SP - 381 EP - 382 PB - Elsevier ER - TY - JOUR A1 - Auer, Simon A1 - Krutsch, Werner A1 - Renkawitz, Tobias A1 - Kubowitsch, Simone A1 - Süß, Franz A1 - Dendorfer, Sebastian T1 - Kognitiver Stress führt zu unphysiologisch erhöhten Kniebelastungen im Profifußball JF - Sports Orthopaedics and Traumatology Y1 - 2020 U6 - https://doi.org/10.1016/j.orthtr.2020.04.122 VL - 36 IS - 2 SP - 202 EP - 203 PB - Elsevier ER - TY - JOUR A1 - Wiesent, Lisa A1 - Schultheiß, Ulrich A1 - Lulla, Philipp A1 - Noster, Ulf A1 - Schratzenstaller, Thomas A1 - Schmid, Christof A1 - Nonn, Aida A1 - Spear, Ashley T1 - Computational analysis of the effects of geometric irregularities and post-processing steps on the mechanical behavior of additively manufactured 316L stainless steel stents JF - PLoS ONE N2 - Advances in additive manufacturing enable the production of tailored lattice structures and thus, in principle, coronary stents. This study investigates the effects of process-related irregularities, heat and surface treatment on the morphology, mechanical response, and expansion behavior of 316L stainless steel stents produced by laser powder bed fusion and provides a methodological approach for their numerical evaluation. A combined experimental and computational framework is used, based on both actual and computationally reconstructed laser powder bed fused stents. Process-related morphological deviations between the as-designed and actual laser powder bed fused stents were observed, resulting in a diameter increase by a factor of 2-2.6 for the stents without surface treatment and 1.3-2 for the electropolished stent compared to the as-designed stent. Thus, due to the increased geometrically induced stiffness, the laser powder bed fused stents in the as-built (7.11 ± 0.63 N) or the heat treated condition (5.87 ± 0.49 N) showed increased radial forces when compressed between two plates. After electropolishing, the heat treated stents exhibited radial forces (2.38 ± 0.23 N) comparable to conventional metallic stents. The laser powder bed fused stents were further affected by the size effect, resulting in a reduced yield strength by 41% in the as-built and by 59% in the heat treated condition compared to the bulk material obtained from tensile tests. The presented numerical approach was successful in predicting the macroscopic mechanical response of the stents under compression. During deformation, increased stiffness and local stress concentration were observed within the laser powder bed fused stents. Subsequent numerical expansion analysis of the derived stent models within a previously verified numerical model of stent expansion showed that electropolished and heat treated laser powder bed fused stents can exhibit comparable expansion behavior to conventional stents. The findings from this work motivate future experimental/numerical studies to quantify threshold values of critical geometric irregularities, which could be used to establish design guidelines for laser powder bed fused stents/lattice structures. KW - Heat treatment KW - Lasers KW - Surface treatments KW - Specimen preparation and treatment KW - Material properties KW - Stiffness KW - Deformation KW - Powders KW - Koronarendoprothese KW - Rapid prototyping KW - Numerische Methode Y1 - 2020 U6 - https://doi.org/10.1371/journal.pone.0244463 N1 - Corresponding author: Lisa Wiesent VL - 15 IS - 12 SP - 1 EP - 30 PB - PLOS ER - TY - JOUR A1 - Schmailzl, Anton A1 - Käsbauer, Johannes A1 - Martan, Jiří A1 - Honnerová, Petra A1 - Schäfer, Felix A1 - Fichtl, Maximilian A1 - Lehrer, Tobias A1 - Prušáková, L. A1 - Tesař, Jiří A1 - Skála, J. A1 - Honner, Milan A1 - Hierl, Stefan T1 - Measurement of Core Temperature through Semi-Transparent Polyamide 6 using Scanner-Integrated Pyrometer in Laser Welding JF - International Journal of Heat and Mass Transfer N2 - Predicting the core temperature during welding is an ambitious aim in many research works. In this work, a 3D-scanner with integrated pyrometer is characterized and used to measure the temperature during quasi-simultaneous laser transmission welding of polyamide 6. However, due to welding in an overlap configuration, the heat radiation emitted from the joining zone of a laser transmission weld has to pass through the upper polymer, which is itself a semi-transparent emitter. Therefore, the spectral filtering of the heat radiation in the upper polymer is taken into account by calibrating the pyrometer for the measurement task. Thermal process simulations are performed to compare the temperature field with the measured temperature signal. The absorption coefficients of the polymers are measured, in order to get precise results from the computation. The temperature signals during welding are in good agreement with the computed mean temperature inside the detection spot, located in the joining area. This is also true for varying laser power, laser beam diameter and the carbon black content in the lower polymer. Both, the computed mean temperature and the temperature signal are representing the core temperature. In order to evaluate the spatial sensitivity of the measurement system, the emitted heat radiation from both polymers is calculated on basis of the computed temperature field. Hereby it is found, that more than 90 percent of the detected heat radiation comes from the joining area, which is a crucial information for contact-free temperature measurement tasks on semi-transparent polymers. KW - Semi-transparent polymer KW - Pyrometer KW - Laser transmission welding KW - Temperature KW - measurement Y1 - 2020 U6 - https://doi.org/10.1016/j.ijheatmasstransfer.2019.118814 VL - 146 IS - January PB - Elsevier ER - TY - CHAP A1 - Maiwald, Frederik A1 - Englmaier, Stephan A1 - Hierl, Stefan T1 - Absorber-free Laser Transmission Welding of Transparent Polymers using Fixed Focus Optics and 3D Laser Scanner T2 - Procedia CIRP N2 - Laser transmission welding is a well-known joining technology for thermoplastics, providing reliable and hermetical sealing without adhesives or particle formation. The main advantages of laser-based energy input - high precision, no additional adhesive and no particle emission - are essential for medical and optical applications. To obtain sufficient absorption in visually transparent polymers, thulium fibre lasers emitting in the polymers’ intrinsic absorption spectrum are used. Optics with high numerical aperture provide large intensity gradients inside the specimen, enabling selective fusing in the joining zone. Although the basic feasibility has already been demonstrated, the welding process lacks stability and productivity. Aim of this work is the determination of optimized settings for a fast and reliable welding process. Thus, the interplay of process parameters as well as their impact on the seam are analysed by thermal simulations. Calculated settings are verified by welding tests with COC, PA6 and PETG, using a fixed-focus optics and a 3D laser scanner with up to 200 mm/s feed rate. Y1 - 2020 U6 - https://doi.org/10.1016/j.procir.2020.09.117 VL - 94 SP - 686 EP - 690 ER - TY - CHAP A1 - Käsbauer, Johannes A1 - Schmailzl, Anton A1 - Prehm, Jens A1 - Loose, Tobias A1 - Hierl, Stefan T1 - Simulation of Quasi-Simultaneous Laser Transmission Welding of Plastics BT - Optimization of Material Parameters in Broad Temperature Range T2 - Procedia CIRP N2 - Thermo-mechanical simulation offers great opportunities to optimize welding processes of plastics. For realistic simulation, the temperature dependent mechanical properties need to be implemented from ambient temperature to temperatures above the flow temperature. Standard test methods are insufficient for characterization in the entire temperature range because close to the flow temperature the material is too soft for tensile tests and too stiff for rheometry. Therefore, an optimization strategy is developed, that determines unknown material parameters by testing in welding simulations. The unknown parameters are iteratively adjusted to minimize the mismatch between computed and measured set-paths. Thus, important process characteristics are calculated realistically, enabling the computer aided assessment of the weld quality. KW - plastics welding KW - simulation KW - material modelling KW - optimization KW - parameterization KW - Kunststoffschweißen KW - Thermomechanische Eigenschaft KW - Simulation Y1 - 2020 U6 - https://doi.org/10.1016/j.procir.2020.09.136 VL - 94 SP - 737 EP - 741 ER - TY - GEN A1 - Käsbauer, Johannes A1 - Schmailzl, Anton A1 - Loose, Tobias A1 - Hierl, Stefan T1 - Thermo-Mechanical Modeling of Quasi-Simultaneous Laser Transmission Welding using LS-DYNA with Focus on Accuracy of Heat Input Calculation T2 - Technology Day 2020 - Plastics on the test rig, Traboch, 04.03.2020 Y1 - 2020 ER - TY - JOUR A1 - Maiwald, Frederik A1 - Hierl, Stefan T1 - Pyrometerbasierte Prozessüberwachung beim Laserkunststoffschweißen JF - Photonik KW - Laserschweissen KW - Kunststoff KW - Prozessüberwachung KW - Pryrometer Y1 - 2020 IS - 52 SP - 22 EP - 25 PB - AT-Fachverl. CY - Fellbach ER - TY - JOUR A1 - Geith, Markus A. A1 - Nothdurfter, Laurenz A1 - Heiml, Manuel A1 - Agrafiotis, Emmanouil A1 - Gruber, Markus A1 - Sommer, Gerhard A1 - Schratzenstaller, Thomas A1 - Holzapfel, Gerhard A. T1 - Quantifying stent-induced damage in coronary arteries by investigating mechanical and structural alterations JF - Acta Biomaterialia N2 - Vascular damage develops with diverging severity during and after percutaneous coronary intervention with stent placement and is the prevailing stimulus for in-stent restenosis. Previous work has failed to link mechanical data obtained in a realistic in vivo or in vitro environment with data collected during imaging processes. We investigated whether specimens of porcine right coronary arteries soften when indented with a stent strut shaped structure, and if the softening results from damage mechanisms inside the fibrillar collagen structure. To simulate the multiaxial loading scenario of a stented coronary artery, we developed the testing device ‘LAESIO’ that can measure differences in the stress-stretch behavior of the arterial wall before and after the indentation of a strut-like stamp. The testing protocol was optimized according to preliminary experiments, more specifically equilibrium and relaxation tests. After chemical fixation of the specimens and subsequent tissue clearing, we performed three-dimensional surface and second-harmonic generation scans on the deformed specimens. We analyzed and correlated the mechanical response with structural parameters of high-affected tissue located next to the stamp indentation and low-affected tissue beyond the injured area. The results reveal that damage mechanisms, like tissue compression as well as softening, fiber dispersion, and the lesion extent, are direction-dependent, and the severity of them is linked to the strut orientation, indentation pressure, and position. The findings highlight the need for further investigations by applying the proposed methods to human coronary arteries. Additional data and insights might help to incorporate the observed damage mechanisms into material models for finite element analyses to perform more accurate simulations of stent-implantations. KW - Percutaneous coronary intervention KW - Stent KW - Mechanical properties KW - Damage mechanism KW - Vascular injury KW - Coronary artery KW - Indentation test KW - Softening KW - Second-harmonic generation imaging KW - Micro-structure Y1 - 2020 U6 - https://doi.org/10.1016/j.actbio.2020.08.016 VL - 116 IS - October SP - 285 EP - 301 PB - Elsevier ER - TY - GEN A1 - Auer, Simon A1 - Krutsch, Werner A1 - Renkawitz, Tobias A1 - Kubowitsch, Simone A1 - Süß, Franz A1 - Dendorfer, Sebastian T1 - Effect of mental demand on leg loading in highly dynamic motion T2 - AnyBody online Webinar, Oct 2020 N2 - Football players have a high risk of leg muscle injuries, especially when exposed to mental stress. Injuries to muscles of the thigh are common in amateur and professional football, representing almost a third of all injuries. These injuries occur primarily in non-contact situations and from overuse. They can lead to a range of costs, including financial costs associated with treatment as well as those associated with long-term recovery, and absence from training and/or competition. Further, there is a high risk of injury recurrence and subsequent injury. Y1 - 2020 ER - TY - JOUR A1 - Chavez, Jhohan A1 - Schorr, Philipp A1 - Kaufhold, Tobias A1 - Zentner, Lena A1 - Zimmermann, Klaus A1 - Böhm, Valter T1 - Influence of Elastomeric Tensioned Members on the Characteristics of Compliant Tensegrity Structures in Soft Robotic Applications JF - Procedia Manufacturing N2 - The use of mechanically prestressed compliant structures in soft robotics is a recently discussed topic. Tensegrity structures, consisting of a set of rigid disconnected compressed members connected to a continuous net of prestressed elastic tensioned members build one specific class of these structures. Robots based on these structures have manifold shape changing abilities and can adapt their mechanical properties reversibly by changing of their prestress state according to specific tasks. In the paper selected aspects on the potential use of elastomer materials in these structures are discussed with the help of theoretical analysis. Therefore, a selected basic tensegrity structure with elastomer members is investigated focusing on the stiffness and shape changing ability in dependence of the nonlinear hyperelastic behavior of the used elastomer materials. The considered structure is compared with a conventional tensegrity structure with linear elastic tensioned members. Finally, selected criterions for the advantageous use of elastomer materials in compliant tensegrity robots are discussed. KW - compliant tensegrity structures KW - soft robotics KW - elastomers Y1 - 2020 U6 - https://doi.org/10.1016/j.promfg.2020.11.048 SN - 2351-9789 VL - 52 SP - 289 EP - 294 PB - Elsevier ER - TY - GEN A1 - Chavez, Jhohan A1 - Henning, S. A1 - Zentner, Lena A1 - Böhm, Valter T1 - Soft tensegrity structures with variable stiffness and shape changing ability T2 - Annual Meeting of the DFG Priority Programme Soft Material Robotic Systems, SPP2100, 02-04. März 2020, Schneverdingen Y1 - 2020 ER - TY - CHAP A1 - Schorr, Philipp A1 - Schale, Florian A1 - Otterbach, Jean Marc A1 - Zentner, Lena A1 - Zimmermann, Klaus A1 - Böhm, Valter T1 - Investigation of a Multistable Tensegrity Robot applied as Tilting Locomotion System T2 - Proceedings of the 2020 IEEE International Conference on Robotics and Automation (ICRA): 31 May-31 August 2020, Paris N2 - This paper describes the development of a tilting locomotion system based on a compliant tensegrity structure with multiple stable equilibrium configurations. A tensegrity structure featuring 4 stable equilibrium states is considered. The mechanical model of the structure is presented and the according equations of motion are derived. The variation of the length of selected structural members allows to influence the prestress state and the corresponding shape of the tensegrity structure. Based on bifurcation analyses a reliable actuation strategy to control the current equilibrium state is designed. In this work, the tensegrity structure is assumed to be in contact with a horizontal plane due to gravity. The derived actuation strategy is utilized to generate tilting locomotion by successively changing the equilibrium state. Numerical simulations are evaluated considering the locomotion characteristics. In order to validate this theoretical approach a prototype is developed. Experiments regarding to the equilibrium configurations, the actuation strategy and the locomotion characteristics are evaluated using image processing tools and motion capturing. The results verify the theoretical data and confirm the working principle of the investigated tilting locomotion system. This approach represents a feasible actuation strategy to realize a reliable tilting locomotion utilizing the multistability of compliant tensegrity structures. KW - actuators KW - bifurcation KW - mechanical stability KW - mobile robots KW - motion control KW - numerical analysis KW - robot dynamics KW - robot kinematics KW - vibration control Y1 - 2020 U6 - https://doi.org/10.1109/ICRA40945.2020.9196706 SP - 2932 EP - 2938 ER - TY - CHAP A1 - Schorr, Philipp A1 - Böhm, Valter A1 - Zentner, Lena A1 - Zimmermann, Klaus ED - Gusikhin, Oleg ED - Madani, Kurosh T1 - Design of a Vibration Driven Motion System Based on a Multistable Tensegrity Structure T2 - ICINCO 2018: proceedings of the 15th International Conference on Informatics in Control, Automation and Robotics, Porto, Portugal, July 29-31, 2018 N2 - In this paper a novel approach to realize a uniaxial bidirectional vibration driven motion system with controllable direction of motion is investigated. The considered motion system bases on a tensegrity structure with multiple stable equilibrium configurations. The structure is in contact with a horizontal plane due to gravity and the actuation is realized by the harmonic change of the length of a selected member. Beside varying the actuation parameters, the direction of motion can be controlled by changing the equilibrium configuration of the tensegrity structure. In this paper the topology of the tensegrity structure and the parameter values are chosen appropriately to provide two symmetric equilibrium configurations. A change of the equilibrium state yields a novel configuration of the entire motion system which is symmetric to the original state. Utilizing the symmetry of the system the same actuation yields an opposite motion. This approach represents a reliable opportunity to control the direction of motion by changing the equilibrium state for constant actuation parameters. This paper focuses on the parameter selection and the design of the actuation of the vibration driven motion system. The working principle of the vibration driven motion system is verified by numerical simulations. This contribution represents the theoretical investigation for the further development of a prototype. KW - Compliant tensegrity structure KW - Vibration driven motion multistability Y1 - 2020 SN - 978-3-030-31992-2 U6 - https://doi.org/10.1007/978-3-030-31993-9_14 VL - 613 SP - 302 EP - 317 PB - Springer CY - Cham ER - TY - JOUR A1 - Keim, Vincent A1 - Paredes, Marcelo A1 - Nonn, Aida A1 - Münstermann, Sebastian T1 - FSI-simulation of ductile fracture propagation and arrest in pipelines BT - Comparison with existing data of full-scale burst tests JF - International Journal of Pressure Vessels and Piping N2 - The fracture propagation and arrest control for pipelines transporting rich natural gases and high vapor pressure liquids is based on the Battelle Two-Curve Model (BTCM). Distinct limitations of this model were demonstrated for past and modern steels and gas mixtures. These can be related to the insufficient description of individual physical processes and interactions between the pipe material and transported mixture during the running ductile fracture. In the past, fluid-structure interaction (FSI) models enabled a more sophisticated, coupled analysis of the failure scenario. To quantify their capability of describing the multi-physical processes, the FSI models need to be verified by experimental data from full-scale burst tests (FSBT). Therefore, this paper deals with the simulation of five FSBTs from the literature on API grade X65 pipes with different pipe geometries, mixtures and initial conditions. The FSI is modeled by the coupled Euler-Lagrange (CEL) method. The modified Mohr-Coulomb (MMC) model is implemented in the CEL framework to describe the deformation and ductile fracture in the X65/L450 pipes. 3D Euler equations are used to calculate the mixture decompression with the GERG-2008 equation of state defining the volumetric behavior of a CO2-rich mixture, CH4 and H2. The extended model considers the effect of soil backfill on the pipe deformation and inertia. The numerical predictions agree well with the experimental findings in terms of the crack propagation speed and arrest length underlining the capability of the developed numerical tool. KW - Running ductile fracture KW - Crack arrest KW - Fluid-structure interaction KW - MMC model KW - CO2 decompression KW - Bruchmechanik KW - Fluid-Struktur-Wechselwirkung KW - Pipeline KW - Simulation Y1 - 2020 U6 - https://doi.org/10.1016/j.ijpvp.2020.104067 VL - 182 IS - May PB - Elsevier ER - TY - JOUR A1 - Prantl, Lukas A1 - Eigenberger, Andreas A1 - Gehmert, Sebastian A1 - Haerteis, Silke A1 - Aung, Thiha A1 - Rachel, Reinhard A1 - Jung, Ernst Michael A1 - Felthaus, Oliver T1 - Enhanced Resorption of Liposomal Packed Vitamin C Monitored by Ultrasound JF - Journal of Clinical Medicine N2 - Vitamin C is an essential nutrient for humans and is involved in a plethora of health-related functions. Several studies have shown a connection between vitamin C intake and an improved resistance to infections that involves the immune system. However, the body cannot store vitamin C and both the elevated oral intake, and the intravenous application have certain disadvantages. In this study, we wanted to show a new formulation for the liposomal packaging of vitamin C. Using freeze etching electron microscopy, we show the formed liposomes. With a novel approach of post-processing procedures of real-time sonography that combines enhancement effects by contrast-like ultrasound with a transducer, we wanted to demonstrate the elevated intestinal vitamin C resorption on four participants. With the method presented in this study, it is possible to make use of the liposomal packaging of vitamin C with simple household materials and equipment for intake elevation. For the first time, we show the enhanced resorption of ingested liposomes using microbubble enhanced ultrasound imaging. KW - ASCORBIC-ACID KW - CEUS KW - CONTRAST AGENT KW - CULTURES KW - DEFICIENCY KW - enhanced resorption KW - GULO KW - immune system KW - liposomal packing KW - MITOCHONDRIAL DYSFUNCTION KW - OXIDATIVE STRESS KW - PHOSPHATIDYLCHOLINE KW - sonography KW - vitamin C Y1 - 2020 U6 - https://doi.org/10.3390/jcm9061616 VL - 9 IS - 6 SP - 1 EP - 12 PB - MDPI CY - Basel ER - TY - JOUR A1 - Prantl, Lukas A1 - Eigenberger, Andreas A1 - Klein, Silvan A1 - Limm, Katharina A1 - Oefner, Peter J. A1 - Schratzenstaller, Thomas A1 - Felthaus, Oliver T1 - Shear Force Processing of Lipoaspirates for Stem Cell Enrichment Does Not Affect Secretome of Human Cells Detected by Mass Spectrometry In Vitro JF - Plastic and Reconstructive Surgery N2 - Background: Lipofilling is one of the most often performed surgical procedures in plastic and reconstructive surgery. Lipoaspirates provide a ready source of stem cells and secreted factors that contribute to neoangiogenesis and fat graft survival. However, the regulations about the enrichment of these beneficial cells and factors are ambiguous. In this study, the authors tested whether a combination of centrifugation and homogenization allowed the enrichment of viable stem cells in lipoaspirates through the selective removal of tumescent solution, blood, and released lipids without significantly affecting the cell secretome. Methods: Human lipoaspirate was harvested from six different patients using water jet–assisted liposuction. Lipoaspirate was homogenized by first centrifugation (3584 rpm for 2 minutes), shear strain (10 times intersyringe processing), and second centrifugation (3584 rpm for 2 minutes). Stem cell enrichment was shown by cell counting after stem cell isolation. Lipoaspirate from different processing steps (unprocessed, after first centrifugation, after homogenization, after second centrifugation) was incubated in serum-free cell culture medium for mass spectrometric analysis of secreted proteins. Results: Lipoaspirate homogenization leads to a significant 2.6 ± 1.75-fold enrichment attributable to volume reduction without reducing the viability of the stem cells. Protein composition of the secretome did not change significantly after tissue homogenization. Considering the enrichment effects, there were no significant differences in the protein concentration of the 83 proteins found in all processing steps. Conclusions: Stem cells can be enriched mechanically without significantly affecting the composition of secreted proteins. Shear-assisted enrichment of lipoaspirate constitutes no substantial manipulation of the cells’ secretome. Y1 - 2020 U6 - https://doi.org/10.1097/PRS.0000000000007343 VL - 146 IS - 6 SP - 749e EP - 758e PB - American Society of Plastic Surgeons ER - TY - CHAP A1 - Rill, Daniel A1 - Butz, Christiane A1 - Rill, Georg ED - Kecskeméthy, Andrés ED - Geu Flores, Francisco T1 - Dynamic Interaction of Heavy Duty Vehicles and Expansion Joints T2 - Multibody Dynamics 2019, Proceedings of the 9th ECCOMAS Thematic Conference on Multibody Dynamics N2 - The “Smart Bridge (Intelligente Brücke)” project cluster, initiated by the German Federal Highway Research Institute (Bundesanstalt für Straßenwesen, BASt) and the Federal Ministry of Transport and Digital Infrastructure (BMVI), focuses on “smart” monitoring devices that allow an efficient and economic maintenance management of bridge infrastructures. Among the participating projects, the one presented herein focuses on the development of a smart expansion joint, to assess the traffic parameters on site. This is achieved by measuring velocity and weight of crossing vehicles. In reference measurements, performed with a three-axle truck and a typical tractor semi-trailer combination with five axles in total, it was shown that the interaction between the vehicle and the expansion joint is highly dynamic and depends on several factors. To get more insight into this dynamic problem, a virtual test rig was set up. Although nearly all vehicle parameters had to be estimated, the simulation results conform very well with the measurements and are robust to vehicle parameter variations. In addition, they indicate a significant influence of the expansion joint dynamic to the peak values of the measured wheel loads, in particular on higher driving velocities. By compensating the relevant dynamic effects in the measurements, a “smart” data processing algorithm makes it possible to determine the actual vehicle weights in random traffic with reliability and appropriate accuracy. Y1 - 2020 SN - 978-3-030-23131-6 U6 - https://doi.org/10.1007/978-3-030-23132-3_56 VL - 53 SP - 471 EP - 478 PB - Springer International Publishing CY - Cham ER - TY - CHAP A1 - Rill, Georg A1 - Arrieta Castro, Abel ED - Klomp, Matthijs ED - Bruzelius, Fredrik ED - Nielsen, Jens ED - Hillemyr, Angela T1 - A Novel Approach for Parametrization of Suspension Kinematics T2 - Advances in Dynamics of Vehicles on Roads and Tracks: Proceedings of the 26th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2019), August 12-16, 2019, Gothenburg, Sweden N2 - n the automotive industry, simulations are needed to analyse the dynamics of vehicles and also of its main components and subsystems, e.g. tires, brakes and suspension systems. These simulations are required for an early-stage development and in consequence, they must deliver realistic results. Suspension systems plays a key role in comfort and safety of road vehicles. They usually consist of rigid links and force elements that are arranged with a specific topology. In addition, some of their functionalities are to carry the weight of the car and the passengers, and maintain a correct wheel alignment. In simulations involving suspension systems, lookup-tables are frequently used. They are obtained from a Kinematic and Compliance (KnC) test and then standardized for a specific vehicle simulation software. Nonetheless, lookup-tables require a reasonable number of characteristic points. Additionally, derivatives, interpolation, and extrapolation are not necessarily smooth. This produces results that depend on the interpolation technique and may be inaccurate. In this paper, a novel method called “design kinematics” is proposed. This method can describe the kinematic properties of almost any type of suspension systems. Comparisons with an analytic calculation and a KnC measurement shown that the design kinematics is able to represent the kinematic and compliance properties of suspension systems extremely well and very efficiently. KW - design Kinematics KW - Kinematic and compliance test KW - Suspension systems Y1 - 2020 SN - 978-3-030-38076-2 U6 - https://doi.org/10.1007/978-3-030-38077-9_210 SP - 1848 EP - 1857 PB - Springer International Publishing CY - Cham ER - TY - CHAP A1 - Rill, Georg T1 - TMeasy 6.0-A handling tire model that incorporates the first two belt eigenmodes T2 - Proceedings of the XI International Conference on Structural Dynamics (EURODYN 2020): Athens, Greece, 23.11.2020 - 26.11.2020 N2 - TMeasy 6.0, an extension to the standard TMeasy tire model of version 5.3, takes the relevant first two rigid body eigenmodes of the belt into consideration. These modes represent the in plane longitudinal and rotational movements of the belt relative to the rim. The dynamics of the longitudinal force is of higher order then and reproduces the tire wheel vibrations, required for indirect tire-pressure monitoring systems (iTPMS), sufficiently well. A tailored implicit solver, which takes the stiff coupling between the longitudinal force and the belt motions into account, still provides real-time performance in addition. Simulation examples show that a rigid body vehicle model equipped with TMeasy 6.0 makes it possible to investigate second generation indirect tire-pressure monitoring systems. KW - TMeasy Tire Model KW - Tire Force Dynamics KW - Frequency Analysis KW - Real-time Simulation KW - Virtual Test Rig Y1 - 2020 U6 - https://doi.org/10.47964/1120.9054.18673 SP - 676 EP - 689 PB - EASD Procedia ER - TY - BOOK A1 - Rill, Georg A1 - Arrieta Castro, Abel T1 - Road Vehicle Dynamics N2 - Road Vehicle Dynamics: Fundamentals and Modeling with MATLAB®, Second Edition combines coverage of vehicle dynamics concepts with MATLAB v9.4 programming routines and results, along with examples and numerous chapter exercises. Improved and updated, the revised text offers new coverage of active safety systems, rear wheel steering, race car suspension systems, airsprings, four-wheel drive, mechatronics, and other topics. Based on the lead author's extensive lectures, classes, and research activities, this unique text provides readers with insights into the computer-based modeling of automobiles and other ground vehicles. Instructor resources, including problem solutions, are available from the publisher. KW - Fahrdynamik Y1 - 2020 SN - 9780429244476 U6 - https://doi.org/10.1201/9780429244476 PB - CRC Press CY - Boca Raton, Fla. ER - TY - BOOK A1 - Purr, Stephan T1 - Datenerfassung für die Anwendung lernender Algorithmen bei der Herstellung von Blechformteilen N2 - Der industrielle Fertigungsprozess von Blechformteilen unterliegt dem Einfluss einer Vielzahl von Parameterschwankungen, die das Umformergebnis signifikant mitbestimmen. Daher treten Qualitätsprobleme scheinbar zufällig auf und verursachen Ausschuss und einen Verlust an Produktivität. Ein vielversprechendes Mittel zur Verbesserung derartiger Prozesse ist der Einsatz von Datenanalysen und lernenden Algorithmen, die jedoch eine große Datenmenge voraussetzten. Bisher fehlten die Datenbasis und geeignete Möglichkeiten zur Datenerfassung für den Einsatz dieser Methoden. In dieser Arbeit wurde eine allgemeingültige und übertragbare Methode zur Erfassung und Speicherung relevanter Einfluss- und Ergebnisgrößen des Herstellprozesses von Blechformteilen entwickelt. Die Methode und die resultierenden Daten sind die Grundlage für die Analyse von Zusammenhängen im Prozess, die Vorhersage der Qualität durch maschinelles Lernen und die Berechnung geeigneter Maschineneinstellungen. Diese Anwendungen wurden in der Arbeit erprobt und die Ergebnisse bewertet. Dadurch konnten die Funktionalität der Datenerfassung und die erwarteten Potentiale bestätigt werden. N2 - The process of industrially producing shaped sheet metal parts is influenced by a large number of fluctuating factors. Therefore, quality problems appear to occur randomly and cause defective parts and a loss of productivity. A suitable way to improve these processes is the application of data analysis and statistical methods like machine learning, which require a large amount of data. So far, the data base and suitable methods for data acquisition are lacking for the use of these methods. Therefore, in this work, a generally valid and transferable method for recording and saving relevant influencing and resultant variables during the series production of sheet metal parts has been developed. This method and the resulting data are the basis for the analysis of correlations in the process, the prediction of quality by learning algorithms and the calculation of suitable press settings. These use cases were tested in the work and the results were evaluated. Thus, the functionality of the data acquisition and the expected potentials could be confirmed. KW - Digitalisierung KW - Umformen KW - Qualitätsmanagement KW - Maschinelles Lernen KW - Data Mining KW - Datenerfassung KW - Ingenieurwissenschaften KW - Maschinenbau KW - Produktionstechnik KW - Blechumformung KW - Tiefziehen KW - Umformtechnik KW - künstliche Intelligenz KW - lernende Algorithmen Y1 - 2020 U6 - https://doi.org/10.25593/978-3-96147-282-6 N1 - Zugl.: Diss., FAU Erlangen-Nürnberg, 2020 PB - FAU University Press ER - TY - THES A1 - Kastenmeier, Andreas T1 - Biegeverhalten faserverstärkter Kunststoffrohre unter Berücksichtigung einer mehrreihigen Bolzenverbindung N2 - In der vorliegenden Arbeit wird die Charakterisierung des mechanischen Verhaltens von auskragenden Rohren aus kohlenstofffaserverstärktem Kunststoff (CFK) mit Querkraftbelastung an einem Ende und einer mehrreihigen Bolzenverbindung am anderen Ende behandelt. Bolzenverbindungen mit Fügepartner aus CFK werden im Stand der Technik nur an ebenen, zug- oder druckbelasteten, Verbindungen untersucht, weshalb der Einfluss der Biegebelastung, der gekrümmten Auflageflächen und des geschlossenen Rohrprofils untersucht und qualifiziert wird. Zudem zeigt sich ein Effekt der Abstützung bzw. resultierenden Verformungsbehinderung. Die Grundlage der Untersuchungen bilden 2-Punkt-Biegeversuche mit Verzerrungs- und Verschiebungsmessungen, die über FE-Modelle numerisch abgebildet und in einer Verzerrungs- und Spannungsanalyse detaillierter ausgewertet werden. Zur Darstellung des Einflusses der Biegebelastung werden zudem reine Zug- und Drucklasten aufgebracht, ausgewertet und abgeglichen. In drei Variationen des Biegeversuchs werden zudem, sowohl experimentell als auch numerisch, Effekte zu einer möglichen Steigerung der Verbindungsfestigkeit untersucht. Dazu zählt die Verwendung von zusätzlichen Schichten aus Titanlegierung im Kraftüberleitungsbereich, ein Versetzen der Bolzen im Umfang und eine Änderung der Abstützung in Lastrichtung. Für das Biegeverhalten der CFK-Rohre im frei auskragenden Bereich werden kontinuumsmechanische Modelle der anisotropen Elastizität für Rohre unter reiner Biegebelastung beschrieben, adaptiert und bezüglich der Ergebnisse bewertet. Um die Vergleichbarkeit der Berechnungsmodelle und Versuche zu gewährleisten, wird einerseits der Einfluss der speziellen Schichtstruktur in gewickelten CFK-Rohren diskutiert und andererseits werden die transversal-isotropen Materialeigenschaften der Einzelschicht an Probekörpern aus den Rohren bestimmt. KW - Kunststoffrohr KW - Kohlenstofffaserverstärkter Kunststoff KW - Krafteinleitung KW - Bolzenverbindung KW - Biegezugfestigkeit KW - Bolzenverbindung KW - Biegeverhalten KW - Rohr KW - Faserverbund KW - Krafteinleitung Y1 - 2020 UR - https://athene-forschung.unibw.de/135000 UR - http://d-nb.info/1229961569/34 N1 - Kooperative Promotion zwischen der Ostbayerischen Technischen Hochschule Regensburg (Prof. Dr.-Ing. Ingo Ehrlich) und der Universität der Bundeswehr München ER - TY - JOUR A1 - Becker, Tatiana I. A1 - Böhm, Valter A1 - Schale, F. A1 - Zimmermann, Klaus T1 - Vibrating sensor unit made of a magnetoactive elastomer with field-adjustable characteristics JF - Journal of Magnetism and Magnetic Materials N2 - The present work deals with the investigation of the oscillatory behavior displayed by a vibrating sensor unit made of a magnetoactive elastomer (MAE). Since this type of smart materials consists of an elastic matrix and micro-magnetic particles, it reveals exceptional magnetic-field-dependent material properties. The forced vibration response under the bending of the MAE unit subjected to in-plane harmonic kinematic excitation of the housing is studied. It is found that the amplitude-frequency characteristics of the MAE unit can be changed considerably by means of an external homogeneous magnetic field. With and without applied field, the unit displays different steady-state responses for the same excitation, and the resonance occurs at various ranges of the excitation frequency. The nonlinear phenomenon of the resonance hysteresis is observed depending on whether the excitation frequency increases or decreases. It is shown that the MAE vibrations can be detected based on the magnetic field distortion measurements. The presented prototype of the MAE-based vibrating unit with field-adjustable “configuration” can be potentially implemented for realization of acceleration sensor systems with adaptive sensitivity. Y1 - 2020 U6 - https://doi.org/10.1016/j.jmmm.2019.166196 VL - 498 IS - March PB - Elsevier ER - TY - CHAP A1 - Böhm, Valter A1 - Schorr, Philipp A1 - Feldmeier, T. A1 - Chavez, Jhohan A1 - Henning, S. A1 - Zimmermann, Klaus A1 - Zentner, Lena T1 - An Approach to Robotic End Effectors Based on Multistable Tensegrity Structures T2 - New Trends in Mechanism and Machine Science: 8th European Conference on Mechanism Science (EuCoMeS), 2020 N2 - In this paper compliant multistable tensegrity structures with discrete variable stiffness are investigated. The different stiffness states result from the different prestress states of these structures corresponding to the equilibrium configurations. Three planar tensegrity mechanisms with two stable equilibrium configurations are considered exemplarily. The overall stiffness of these structures is characterized by investigations with regard to their geometric nonlinear static behavior. Dynamical analyses show the possibility of the change between the equilibrium configurations and enable the derivation of suitable actuation strategies. KW - Compliant tensegrity structure KW - Multiple states of self-equilibrium KW - Variable stiffness Y1 - 2020 U6 - https://doi.org/10.1007/978-3-030-55061-5_53 SP - 470 EP - 478 PB - Springer ER - TY - CHAP A1 - Maiwald, Frederik A1 - Englmaier, Stephan A1 - Hierl, Stefan T1 - Online pyrometry for weld seam localization in absorber-free laser transmission welding of transparent polymers T2 - 21st International Symposium on Laser Precision Microfabrication: Dresden, 26.06.2020 N2 - Optical and medical devices made of transparent polymers are gaining popularity because of its cost advantages. The manufacturing technology must be able to meet the high demands of these applications. Advantages of laser transmission welding – contactless input of energy, precision, no adhesives and no particle formation – can be exploited here. For absorber-free welding, lasers emitting in the polymers‘ intrinsic absorption spectrum are used. Focusing the laser beam with high NA enables selective fusing of the joining zone. Since a molten upper surface leads to visible and palpable irregularities, the lateral expansion of the weld seam is monitored in this work. Welding tests with 1 mm thick plates of COC are performed and monitored by pyrometry. Distances between seam and surface measured in thin cuts and are compared with the pyrometer signal. This shows that the localization of the weld seam is possible and proper and faulty parts can be distinguished by pyrometry. KW - Laserdurchstrahlschweissen KW - Kunststoff KW - Transparenz KW - Schweißnaht KW - Wärmestrahlung KW - Pyrometrie KW - Prozessüberwachung Y1 - 2020 UR - http://www.jlps.gr.jp/en/proc/lpm/20/073.pdf ER - TY - CHAP A1 - Ketterl, Hermann A1 - Hoelscher, Clemens A1 - Gotzler, Julian A1 - Grill, Oliver A1 - Heinrich, Tobias A1 - Mayer, Anton A1 - Reiter, Fabian A1 - Mühlbauer, Simon A1 - Weinzierl, Stefan ED - Jäkel, Jens ED - Thiel, Robert T1 - Autonomer Hackroboter T2 - Tagungsband AALE 2020: Automatisierung und Mensch-Technik-Interaktion, 17. Fachkonferenz, 4. bis 6. März 2020, Leipzig Y1 - 2020 SN - 978-3-8007-5180-8 VL - 2020 PB - VDE-Verlag ER - TY - CHAP A1 - Ketterl, Hermann A1 - Heinrich, Tobias A1 - Reitmeier, Torsten A1 - Hoelscher, Clemens ED - Jäkel, Jens ED - Thiel, Robert T1 - Emissionsabhängige Leistungsregelung für BHKW’s T2 - Tagungsband AALE 2020: Automatisierung und Mensch-Technik-Interaktion, 17. Fachkonferenz, 4. bis 6. März 2020, Leipzig Y1 - 2020 SN - 978-3-8007-5180-8 VL - 2020 PB - VDE-Verlag ER - TY - JOUR A1 - Wiesent, Lisa A1 - Schultheiß, Ulrich A1 - Lulla, Philipp A1 - Nonn, Aida A1 - Noster, Ulf T1 - Mechanical properties of small structures built by selective laser melting 316 L stainless steel – a phenomenological approach to improve component design JF - Materials Science & Engineering Technology JF - Materialwissenschaft und Werkstofftechnik N2 - Experimental investigations are conducted to quantify the influence of specimen thickness and orientation on the mechanical properties of selective laser melted stainless steel 316 L. The results indicate that the mechanical strength and ductility increase with increasing specimen thickness until a saturation value is reached from a specimen thickness of about 2 mm. Specimen orientation dependency is pronounced for thin specimens (<1.5 mm), whereas only small deviations in strength are observed for thicker specimens with orientations of 30°, 45° and 90° to build direction. The mechanical properties of the specimen orientation of 0° to build direction shows great deviation to the other orientations and the smallest overall strength. A reliable design of selective laser melted components should account for specimen thickness and orientation, e. g. by a correction factor. Furthermore, it is recommended to avoid loads vertical (90°) and parallel (0°) to build direction to guarantee higher ductility and strength. T2 - Mechanische Eigenschaften von kleinen Strukturen aus selektiv lasergeschmolzenem 316 L Edelstahl – ein phänomenologischer Ansatz zur Verbesserung des Bauteildesigns Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-14718 N1 - Corresponding author: Lisa Wiesent VL - 51 IS - 12 SP - 1615 EP - 1629 PB - Wiley ER - TY - JOUR A1 - Engelhardt, Lucas A1 - Melzner, Maximilian A1 - Havelkova, Linda A1 - Fiala, Pavel A1 - Christen, Patrik A1 - Dendorfer, Sebastian A1 - Simon, Ulrich T1 - A new musculoskeletal AnyBodyTM detailed hand model JF - Computer Methods in Biomechanics and Biomedical Engineering N2 - Musculoskeletal research questions regarding the prevention or rehabilitation of the hand can be addressed using inverse dynamics simulations when experiments are not possible. To date, no complete human hand model implemented in a holistic human body model has been fully developed. The aim of this work was to develop, implement, and validate a fully detailed hand model using the AnyBody Modelling System (AMS) (AnyBody, Aalborg, Denmark). To achieve this, a consistent multiple cadaver dataset, including all extrinsic and intrinsic muscles, served as a basis. Various obstacle methods were implemented to obtain with the correct alignment of the muscle paths together with the full range of motion of the fingers. These included tori, cylinders, and spherical ellipsoids. The origin points of the lumbrical muscles within the tendon of the flexor digitorum profundus added a unique feature to the model. Furthermore, the possibility of an entire patient-specific scaling based on the hand length and width were implemented in the model. For model validation, experimental datasets from the literature were used, which included the comparison of numerically calculated moment arms of the wrist, thumb, and index finger muscles. In general, the results displayed good comparability of the model and experimental data. However, the extrinsic muscles showed higher accordance than the intrinsic ones. Nevertheless, the results showed, that the proposed developed inverse dynamics hand model offers opportunities in a broad field of applications, where the muscles and joint forces of the forearm play a crucial role. KW - Musculoskeletal KW - hand KW - AnyBody KW - inverse dynamics KW - moment arm Y1 - 2020 U6 - https://doi.org/10.1080/10255842.2020.1851367 VL - 24 IS - 7 SP - 777 EP - 787 PB - Taylor & Francis ER - TY - JOUR A1 - Chavez, Jhohan A1 - Böhm, Valter A1 - Becker, Tatiana I. A1 - Gast, Simon A1 - Zeidis, Igor A1 - Zimmermann, Klaus T1 - Actuators based on a controlled particle-matrix interaction in magnetic hybrid materials for applications in locomotion and manipulation systems JF - Physical Sciences Reviews N2 - The paper deals with the investigation of magneto-sensitive elastomers (MSE) and their application in technical actuator systems. MSE consist of an elastic matrix containing suspended magnetically soft and/or hard particles. Additionally, they can also contain silicone oil, graphite particles, thermoplastic components, etc., in various concentrations in order to tune specific properties such as viscosity, conductivity and thermoelasticity, respectively. The focuses of investigations are the beneficial properties of MSE in prototypes for locomotion and manipulation purposes that possess an integrated sensor function. The research follows the principle of a model-based design, i.e. the working steps are ideation, mathematical modelling, material characterization as well as building first functional models (prototypes). The developed apedal (without legs) and non-wheeled locomotion systems use the interplay between material deformations and the mechanical motion in connection with the issues of control and stability. Non-linear friction phenomena lead to a monotonous forward motion of the systems. The aim of this study is the design of such mechanical structures, which reduce the control costs. The investigations deal with the movement and control of ‘intelligent’ mechanisms, for which the magnetically field-controlled particle-matrix interactions provide an appropriate approach. The presented grippers enclose partially gripped objects, which is an advantage for handling sensitive objects. Form-fit grippers with adaptable contour at the contact area enable a uniform pressure distribution on the surface of gripped objects. Furthermore, with the possibility of active shape adaptation, objects with significantly differing geometries can be gripped. To realise the desired active shape adaptation, the effect of field-induced plasticity of MSE is used. The first developed prototypes mainly confirm the functional principles as such without direct application. For this, besides the ability of locomotion and manipulation itself, further technological possibilities have to be added to the systems. The first steps are therefore being taken towards integrated MSE based adaptive sensor systems. KW - apedal locomotion systems KW - field-controlled particle-matrix interaction KW - field-induced plasticity KW - form-fit gripper KW - integrated sensor-actuator systems KW - magneto-sensitive elastomer Y1 - 2020 U6 - https://doi.org/10.1515/psr-2019-0087 VL - 7 IS - 11 SP - 1263 EP - 1290 PB - de Gruyter ER - TY - JOUR A1 - Becker, Tatiana I. A1 - Raikher, Yuriy L. A1 - Stolbov, Oleg V. A1 - Böhm, Valter A1 - Zimmermann, Klaus T1 - Magnetoactive elastomers for magnetically tunable vibrating sensor systems JF - Physical Sciences Reviews N2 - Magnetoactive elastomers (MAEs) are a special type of smart materials consisting of an elastic matrix with embedded microsized particles that are made of ferromagnetic materials with high or low coercivity. Due to their composition, such elastomers possess unique magnetic field-dependent material properties. The present paper compiles the results of investigations on MAEs towards an approach of their potential application as vibrating sensor elements with adaptable sensitivity. Starting with the model-based and experimental studies of the free vibrational behavior displayed by cantilevers made of MAEs, it is shown that the first bending eigenfrequency of the cantilevers depends strongly on the strength of an applied uniform magnetic field. The investigations of the forced vibration response of MAE beams subjected to in-plane kinematic excitation confirm the possibility of active magnetic control of the amplitude-frequency characteristics. With change of the uniform field strength, the MAE beam reveals different steady-state responses for the same excitation, and the resonance may occur at various ranges of the excitation frequency. Nonlinear dependencies of the amplification ratio on the excitation frequency are obtained for different magnitudes of the applied field. Furthermore, it is shown that the steady-state vibrations of MAE beams can be detected based on the magnetic field distortion. The field difference, which is measured simultaneously on the sides of a vibrating MAE beam, provides a signal with the same frequency as the excitation and an amplitude proportional to the amplitude of resulting vibrations. The presented prototype of the MAE-based vibrating unit with the field-controlled “configuration” can be implemented for realization of acceleration sensor systems with adaptable sensitivity. The ongoing research on MAEs is oriented to the use of other geometrical forms along with beams, e.g. two-dimensional structures such as membranes. KW - adaptable sensor unit KW - amplification ratio KW - bending vibration KW - eigenfrequency KW - Magnetic field control KW - magnetoactive elastomer Y1 - 2020 U6 - https://doi.org/10.1515/psr-2019-0125 SN - 2365-659X VL - 7 IS - 10 SP - 1 EP - 28 PB - de Gruyter ER - TY - JOUR A1 - Bruni, S. A1 - Meijaard, J. P. A1 - Rill, Georg A1 - Schwab, A. L. T1 - State-of-the-art and challenges of railway and road vehicle dynamics with multibody dynamics approaches JF - Multibody System Dynamics N2 - A review of the current use of multibody dynamics methods in the analysis of the dynamics of vehicles is given. Railway vehicle dynamics as well as road vehicle dynamics are considered, where for the latter the dynamics of cars and trucks and the dynamics of single-track vehicles, in particular motorcycles and bicycles, are reviewed. Commonalities and differences are shown, and open questions and challenges are given as directions for further research in this field. KW - AUTOMATIC-GENERATION KW - BICYCLE DYNAMICS KW - Bicycles KW - CREEP FORCES KW - FREIGHT WAGON KW - LATERAL DYNAMICS KW - LINEAR-MODEL KW - Motorcycles KW - NON-HERTZIAN KW - PASSIVE RIDER KW - Railway vehicles KW - Review KW - Road vehicles KW - ROLLING-CONTACT KW - vehicle dynamics KW - WHEELSET-TRACK INTERACTION Y1 - 2020 U6 - https://doi.org/10.1007/s11044-020-09735-z VL - 49 IS - 1 SP - 1 EP - 32 PB - Springer ER - TY - JOUR A1 - Mikhaeil, Makram A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - On the development of an innovative adsorber plate heat exchanger for adsorption heat transformation processes; an experimental and numerical study JF - Energy N2 - An innovative adsorber plate heat exchanger (APHE), which is developed for application in adsorption heat pumps, chillers and thermal energy storage systems, is introduced. A test frame has been constructed as a representative segment of the introduced APHE for applying loose grains of AQSOA-Z02. Adsorption kinetic measurements have been carried out in a volumetric large-temperature-jump setup under typical operating conditions of adsorption processes. A transient 2-D model is developed for the tested sample inside the setup. The measured temporal uptake variations with time have been fed to the model, through which a micro-pore diffusion coefficient at infinite temperature of 2 E−4 [m2s−1] and an activation energy of 42.1 [kJ mol−1] have been estimated. A 3-D model is developed to simulate the combined heat and mass transfer inside the APHE and implemented in a commercial software. Comparing the obtained results with the literature values for an extruded aluminium adsorber heat exchanger coated with a 500 μm layer of the same adsorbent, the differential water uptake obtained after 300 s of adsorption (8.2 g/100 g) implies a sound enhancement of 310%. This result proves the great potential of the introduced APHE to remarkably enhance the performance of adsorption heat transformation appliances. KW - Adsorber heat exchanger KW - Plate heat exchanger KW - Adsorption kinetics KW - Dynamic simulation Y1 - 2020 U6 - https://doi.org/10.1016/j.energy.2020.118272 N1 - Corresponding author: Belal Dawoud VL - 207 IS - September SP - 1 EP - 13 PB - Elsevier ER - TY - JOUR A1 - Prem, Nina A1 - Sindersberger, Dirk A1 - Striegl, Birgit A1 - Böhm, Valter A1 - Monkman, Gareth J. T1 - Shape memory effects using magnetoactive Boron-organo-silicon oxide polymers JF - Macromolecular Chemistry and Physics N2 - Thermomechanical shape memory materials have certain disadvantages when it comes to 3D volumetric reproduction intended for rapid prototyping or robotic prehension. The need to constantly supply energy to counteract elastic retraction forces in order to maintain the required geometry, together with the inability to achieve conformal stability at elevated temperatures, limits the application of thermal shape memory polymers. Form removal also presents problems as most viscoelastic materials do not ensure demolding stability. This work demonstrates how magnetoactive boron−organo−silicon oxide polymers under the influence of an applied magnetic field can be used to achieve energy free sustainable volumetric shape memory effects over extended periods. The rheopectic properties of boron−organo−silicon oxide materials sustain form removal without mold distortion. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-23205 N1 - Corresponding Author: Gareth J. Monkman VL - 221 IS - 15 SP - 1 EP - 8 PB - Wiley ER - TY - JOUR A1 - Schecklmann, Martin A1 - Schmausser, Maximilian A1 - Klinger, Felix A1 - Kreuzer, Peter M. A1 - Krenkel, Lars A1 - Langguth, Berthold T1 - Resting motor threshold and magnetic field output of the figure-of-8 and the double-cone coil JF - scientific reports N2 - The use of the double-cone (DC) coil in transcranial magnetic stimulation (TMS) is promoted with the notion that the DC coil enables stimulation of deeper brain areas in contrast to conventional figure-of-8 (Fo8) coils. However, systematic comparisons of these two coil types with respect to the spatial distribution of the magnetic field output and also to the induced activity in superficial and deeper brain areas are limited. Resting motor thresholds of the left and right first dorsal interosseous (FDI) and tibialis anterior (TA) were determined with the DC and the Fo8 coil in 17 healthy subjects. Coils were orientated over the corresponding motor area in an angle of 45 degrees for the hand area with the handle pointing in posterior direction and in medio-lateral direction for the leg area. Physical measurements were done with an automatic gantry table using a Gaussmeter. Resting motor threshold was higher for the leg area in contrast to the hand area and for the Fo8 in contrast to the DC coil. Muscle by coil interaction was also significant providing higher differences between leg and hand area for the Fo8 (about 27%) in contrast to the DC coil (about 15%). Magnetic field strength was higher for the DC coil in contrast to the Fo8 coil. The DC coil produces a higher magnetic field with higher depth of penetration than the figure of eight coil. KW - ANTERIOR CINGULATE CORTEX KW - CONNECTIVITY KW - Depression KW - FRONTAL-CORTEX KW - PREDICTOR KW - RTMS KW - STIMULATION KW - TMS Y1 - 2020 U6 - https://doi.org/10.1038/s41598-020-58034-2 VL - 10 IS - 1 PB - Nature ER - TY - JOUR A1 - Birkenmaier, Clemens A1 - Dornia, Christian A1 - Lehle, Karla A1 - Müller, Thomas A1 - Gruber, Michael Andreas A1 - Philipp, Alois A1 - Krenkel, Lars T1 - Analysis of Thrombotic Deposits in Extracorporeal Membrane Oxygenators by High-resolution Microcomputed Tomography: A Feasibility Study JF - ASAIO Journal / American Society for Artificial Internal Organs N2 - Coagulative disorders, especially clotting during extracorporeal membrane oxygenation, are frequent complications. Direct visualization and analysis of deposits in membrane oxygenators using computed tomography (CT) may provide an insight into the underlying mechanisms causing thrombotic events. However, the already established multidetector CT1 (MDCT) method shows major limitations. Here, we demonstrate the feasibility of applying industrial micro-CT (μCT) to circumvent these restrictions. Three clinically used membrane oxygenators were investigated applying both MDCT and μCT. The scans were analyzed in terms of clot volume and local clot distribution. As validation, the clot volume was also determined from the fluid volume, which could be filled into the respective used oxygenator compared to a new device. In addition, cross-sectional CT images were compared with crosscut oxygenators. Based on the μCT findings, a morphological measure (sphericity) for assessing clot structures in membrane oxygenators is introduced. Furthermore, by comparing MDCT and μCT results, an augmentation of the MDCT method is proposed, which allows for improved clot volume determination in a clinical setting. Y1 - 2020 U6 - https://doi.org/10.1097/MAT.0000000000001089 SN - 1538-943X VL - 66 IS - 8 SP - 922 EP - 928 PB - Lippincott Williams & Wilkins ER - TY - CHAP A1 - Lindner, Matthias G. A1 - Berndt, Dominik A1 - Tschurtschenthal, Karl A1 - Ehrlich, Ingo A1 - Jungbauer, Bastian A1 - Schreiner, Rupert A1 - Pipa, Andrei V. A1 - Hink, Rüdiger A1 - Foest, Rüdiger A1 - Brandenburg, Ronny A1 - Neuwirth, Daniel A1 - Karpen, Norbert A1 - Bonaccurso, Elmar A1 - Weichwald, Robert A1 - Max, Alexander A1 - Caspari, Ralf T1 - Aircraft Icing Mitigation by DBD-based Micro Plasma Actuators T2 - AIAA AVIATION 2020 FORUM: June 15-19, 2020 N2 - We present the application of plasma actuators as a technology for ice prevention at airfoils. The miniaturized dielectric barrier discharge (DBD) plasma actuators (PA) were fabricated by means of microelectromechanical systems (MEMS). We elucidate how to make the actuator samples scalable and applicable to any desired shape by the use of flexible inorganic zirconia substrates. For this purpose, we applied our developed embedding method to integrate the micro actuators in modern carbon/glass fiber reinforced polymer (CFRP/GFRP) materials. Next, the embedded actuator samples were mounted on a mechanical air profile-like fixture and placed in the icing wind tunnel iCORE. The samples were tested in rime ice conditions at temperatures of -15 to -20° C and air speeds up to 30 m/s. Unlike other groups we used a thin film zirconia substrate as dielectric for the plasma actuator. Due to the low substrate thickness of just 150 µm, an operating voltage of 2 kVRMS is already sufficient enough for a stable plasma formation. The experiments show that the operated actuator was able to prevent the ice formation and first indications of a De-icing function were also found. Hence, we show that it is feasible to realize an anti-icing system with zirconia-based plasma actuators operated at lower voltages compared to conventional ones. Y1 - 2020 U6 - https://doi.org/10.2514/6.2020-3243 ER - TY - BOOK A1 - Rill, Georg A1 - Schaeffer, Thomas A1 - Borchsenius, Fredrik T1 - Grundlagen und computergerechte Methodik der Mehrkörpersimulation N2 - Dieses Lehrbuch stellt die Methoden der Mehrkörpersimulation anschaulich dar und erläutert an einfachen Beispielen die Vor- und Nachteile bei der praktischen Anwendung. In den Text integrierte Matlab-Skripte und -Funktionen verdeutlichen die einzelnen Methoden. Die Modellbildung, die mathematische Beschreibung und die numerische Simulation von Systemen starrer Körper bilden dabei die Schwerpunkte. Konkrete Beispiele beinhalten einen Bungee-Sprung, die Eigendynamik eines Traktors mit Vorderachsfederung, das Hubschrauberrotorblatt sowie eine Pkw-Vorderachse. Die Lösungen zu den Übungsaufgaben und die im Text integrierten Matlab-Beispiele, die zum Teil durch Animationen angereichert sind, sowie zusätzliche Beispiele und Anwendungen stehen auf der Verlagshomepage beim Buch zum Download zur Verfügung und ermöglichen dadurch auch ein effizientes Selbststudium. Y1 - 2020 SN - 978-3-658-28911-9 U6 - https://doi.org/10.1007/978-3-658-28912-6 PB - Springer Fachmedien CY - Wiesbaden ET - 4. Aufl. ER -