TY - JOUR A1 - Saveliev, Dmitry V. A1 - Belyaeva, Inna A. A1 - Chashin, Dmitri V. A1 - Fetisov, Leonid Y. A1 - Shamonin (Chamonine), Mikhail T1 - Large Wiedemann effect in a magnetoactive elastomer JF - Journal of Magnetism and Magnetic Materials N2 - Large twists of a soft tube (hollow cylinder) in helical magnetic fields are presented for the first time. Such a phenomenon is usually denoted as the Wiedemann effect. The tube is fabricated from a soft magnetoactive elastomer material with the shear modulus of about 56 kPa. The composite material comprises 80 mass% of micrometer-sized iron particles embedded into a polydimethylsiloxane matrix. The circular magnetic field is generated by an electric current in a straight wire passing through the inner hole of the tube. The maximum value of approximately 350″/cm is observed in a longitudinal magnetic field of a few kA/m overlapped with a circumferential magnetic field of about 1.4 kA/m on the surface of the inner hole. A pronounced hysteresis in the dependence of the Wiedemann effect on the circular magnetic field is found. The ways to enhance the Wiedemann twist in magnetoactive elastomers are discussed. The observed large effect is promising for application in magnetic-field controlled torsional actuators, in particular for soft robotics. Y1 - 2020 U6 - https://doi.org/10.1016/j.jmmm.2020.166969 VL - 511 IS - October 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 - 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 - 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 - BOOK A1 - Freni, Angelo A1 - Dawoud, Belal A1 - Bonaccorsi, Lucio Maria A1 - Chmielewski, Stefanie A1 - Frazzica, Andrea A1 - Calabrese, Luigi A1 - Restuccia, Giovanni T1 - Characterization of Zeolite-Based Coatings for Adsorption Heat Pumps N2 - This book proposes a radically new approach for characterizing thermophysical and mechanical properties of zeolite-based adsorbent coatings for Adsorptive Heat Transformers (AHT). It presents a developed standard protocol for the complete characterization of advanced coated adsorbers. Providing an in-depth analysis of the different procedures necessary for evaluating the performance of adsorbers, it also presents an analysis of their stability under the hydrothermal and mechanical stresses during their entire life cycle. Adsorptive Heat Transformers (AHT), especially adsorption chillers and heat pumps, are considered to be promising technologies to increase thermal energy efficiency. Nevertheless, an overall increase in performance of this apparatus is necessary for them to be considered a mature technology to be used commercially. Development of innovative coated adsorbers can be perceived as a key issue for the enhancement of AHT technology. This procedure relies on the deposition, either by means of a binder or by direct crystallization, of the adsorbent material over a metallic heat exchanger, aiming at the improvement of the heat transfer between the external heat source and the adsorbent itself. This book offers a valuable resource to those working on the development of novel adsorbent materials and advanced adsorbent beds for heating and cooling applications. It is also intended for researchers interested in renewable energy and energy efficiency. KW - AHT KW - Adsorbent Coatings KW - Adsorption KW - Adsorptive Heat Transformers KW - Stability Verification KW - Zeolite-based Adsorbent Coatings KW - Zeolite-coated Heat Pumps Y1 - 2015 U6 - https://doi.org/10.1007/978-3-319-09327-7 PB - Springer CY - Berlin ER - TY - CHAP A1 - Schiedermeier, Maximilian A1 - Rettner, Cornelius A1 - Steiner, Marcel A1 - März, Martin T1 - Dual-inverter control synchronization strategy to minimize the DC-link capacitor current T2 - 2020 IEEE Vehicle Power and Propulsion Conference (VPPC), 18 November 2020 - 16 December 2020, Gijon, Spain N2 - This paper proposes the possible switching synchronization strategies of an automotive dual-inverter against the background of minimizing the RMS DC-link capacitor current. The publication mainly focuses on the straight-ahead motion of a rear axle with one electric drive per wheel. In addition to it, a dual-inverter consisting of two subinverters with a common DC-link capacitor is taken into consideration. These sub-inverters each have three phases and are based on a 2-level voltage-source-topology. To control the electrical machines, the continuous Space-Vector-Modulation strategy is used. For this application, different control signal synchronization strategies of the two sub-inverters of the dualinverter are presented. Apart from the existing strategies, this paper proposes a new method, which inherits a compromise between low complexity and high effectiveness. In contrast to previous publications, the resulting capacitor currents are quantified and subsequentlyevaluated. This novel quantification, which is dependent on the dual-inverter’s operating point, provides a base for targeted dimensioning of the capacitor. Moreover, this forms the foundation for further investigations of vehicle’s cornering, as well as for the possible synchronization of stand-alone inverters. In the context of this publication, the presented results are verified by experimentally determined data of a motor-inverter system. KW - Axles KW - Capacitors KW - Complexity theory KW - DC-link capacitor KW - Dual-inverter KW - interleaved inverters KW - Inverters KW - space vector modulation (SVM) KW - Switches KW - Synchronization KW - Voltage source inverter (VSI) KW - Wheels Y1 - 2020 U6 - https://doi.org/10.1109/VPPC49601.2020.9330921 SP - 1 EP - 6 PB - IEEE ER - TY - CHAP A1 - Koder, Alexander A1 - Zacherl, Florian A1 - Rabl, Hans-Peter A1 - Mayer, Wolfgang A1 - Gruber, Georg A1 - Dotzer, Thomas T1 - Jatropha Oil as an Alternative Fuel for Modern Diesel Engines - Injection Characteristics and EGR-Compatibility T2 - WCX 17: SAE World Congress 2017 N2 - An effective way to reduce greenhouse gas emissions (GHGs) is to use rurally produced straight jatropha oil as a substitute for diesel fuel. However, the different physical and chemical properties of straight vegetable oils (SVOs) require a customized setup of the combustion engine, particularly of the injection timing and quantity. Therefore, this study demonstrates the differences in the injection and combustion processes of jatropha oil compared to diesel fuel, particularly in terms of its compatibility with exhaust gas recirculation (EGR). A 2.2 l common-rail diesel engine with a two-stage turbocharging concept was used for testing. To examine the differences in injection rate shaping of diesel fuel and jatropha oil, the injector was tested with an injection rate analyzer using both the fuels. To investigate the combustion process, the engine was mounted at an engine test bench and equipped with a cylinder pressure indication system. All limited emissions, as well as fuel consumption, were measured. Various injection strategies, boost and rail pressure levels were tested at different EGR rates in terms of their impact on the combustion process. EGR in particular offers a great potential in the case of jatropha oil combustion due to its oxygen content. In addition, the investigation of injection rate shaping in combination with cylinder pressure analysis allowed a detailed thermodynamic evaluation of the combustion process. Ignition delay (ID) was also analyzed using a new method to calculate the start of combustion (SOC) Y1 - 2017 U6 - https://doi.org/10.4271/2017-01-5000 PB - SAE International 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 - JOUR A1 - Hansen, B. A1 - Hoebler, Michael A1 - Purr, S. A1 - Meinhardt, J. A1 - Merklein, M. T1 - Basics for inline measurement of tribological conditions in series production of car body parts JF - IOP Conference Series: Materials Science and Engineering N2 - The quality of car body parts in series production is strongly dependent on the tribological behavior. Fluctuating material properties such as the sheet roughness and the amount of lubricant have an influence on the forming process. On the basis of large amounts of data it is possible to investigate the friction behavior in series production and to make process adjustments if required. Therefore, inline measurement systems have a great potential to detect the sheet roughness during the cutting process of blanks in the coil line. Furthermore, contactless systems are advantageous as they do not damage the surface. Nevertheless, the optical measuring is influenced by the lubricant layer on top of the surface. Therefore, the previously unknown impact of the lubricant on the measuring result is investigated. Within this study, stationary optical roughness measurements have been conducted using different amounts of lubricant on hot-dip galvanized EDT steel. The results demonstrate the influence of different amounts of lubricant on the sheet roughness measurement. Hence, it is possible to correct the inline measuring results and gain knowledge of fluctuating surface roughness. In addition, strip drawing test has been carried out to investigate the effect of fluctuating tribological conditions. Y1 - 2019 U6 - https://doi.org/10.1088/1757-899x/651/1/012050 VL - 651 PB - IOP Publishing ER - TY - JOUR A1 - Briem, Ulrich T1 - Biegesteifigkeit von Drahtseilen JF - Technische Logistik Y1 - 2019 IS - 11-12 SP - 24 EP - 25 PB - Huss-Medien CY - Berlin ER - TY - CHAP A1 - Bresinsky, Markus A1 - Reusner, Florian von T1 - GLOBE – Learn and Innovate Digitization by a Virtual Collaboration Exercise and Living Lab T2 - Interactivity, Game Creation, Design, Learning, and Innovation. 6th International Conference, ArtsIT 2017, and Second International Conference, DLI 2017, Heraklion, Crete, Greece, October 30–31, 2017, Proceedings N2 - This paper presents an advanced interactive learning platform .dot that implements the GLOBE exercise, using innovative information and communication technologies to enhance learning and development of management and leadership skills in a complex organizational setting. GLOBE on the one hand focuses on competences around ICT and virtual collaboration, and on the other hand on digital transformation, technologies and tools at higher education institutions. By this applied science, learning and developing on the real-world platform, analysis and drive of digital innovation and transformation can be fostered. The main goal is to co-create knowledge and solutions in the following focused subjects: Management and leadership of multidisciplinary, multinational and multicultural virtual and real collaboration in a complex organizational environment. GLOBE uses real world scenarios (e.g. United Nations mission) and involves real world actors. This comprehensive educational approach should enhance learning techniques and leverage learning progress with hands-on experiences and applied science in the context of ICT and virtual collaboration, and the embodied dynamics of behavior to support innovation and development. KW - Digitization KW - Experiential learning KW - Human factors KW - ICT KW - Interactive and collaborative learning KW - Living Lab KW - Open innovation KW - Problem-based learning KW - Virtual collaboration Y1 - 2018 U6 - https://doi.org/10.1007/978-3-319-76908-0_26 SP - 273 EP - 281 PB - Springer Nature ER - TY - JOUR A1 - Koder, Alexander A1 - Schwanzer, Peter A1 - Zacherl, Florian A1 - Rabl, Hans-Peter A1 - Mayer, Wolfgang A1 - Gruber, Georg A1 - Dotzer, Thomas T1 - Combustion and emission characteristics of a 2.2L common-rail diesel engine fueled with jatropha oil, soybean oil, and diesel fuel at various EGR-rates JF - Fuel N2 - To investigate the combustion and emission behavior of straight vegetable oils (SVO), jatropha oil, soybean oil, and diesel fuel were tested. For this research, a 2.2L common-rail engine with a two-stage turbocharging concept was equipped with a cylinder pressure indication system, an exhaust-gas analyzer, an AVL Micro Soot sensor and a Scanning Mobility Particle Sizer 3936 (SMPS) device to detect the particle-size-distribution (PSD). At a low and mid-load engine-operating point (EOP), the thermodynamic and emissions were investigated under various exhaust gas recirculation (EGR) rates with respect to the PSD. Moreover, the injection behavior of the three test fuels was analyzed separately using an injection rate analyzer. This procedure facilitates the thermodynamic investigations of the engine process and allows the calculation of the hydraulic delay (HD) as well as the ignition delay (ID). The ID of the SVO fuels compared to diesel fuel was found to be lower at all engine-operating modes, while jatropha oil always showed the shortest ID. In the particulate-nitrogen oxide (NOX) trade-off, the SVO fuels showed higher particulate matter (PM) emissions at the low-load EOP, whereas the PM emissions of diesel fuel overtop the SVO fuels at a higher engine load. With increased EGR-rates, a rise in the particle size was observed for all fuels. At the low-load EOP, the SVO fuels showed larger particles for high EGR-rates. This effect also changed by increasing the engine-load to the mid-load EOP, wherein the particle size of the diesel fuel emissions is higher by applying elevated EGR-rates. KW - BEHAVIOR KW - BLENDS KW - Exhaust gas recirculation KW - IGNITION KW - INJECTION KW - Jatropha oil KW - KARANJA KW - Particle-size-distribution KW - PERFORMANCE KW - RME KW - Soybean oil KW - Straight vegetable oil combustion KW - VEGETABLE-OILS Y1 - 2018 U6 - https://doi.org/10.1016/j.fuel.2018.04.147 VL - 228 IS - September SP - 23 EP - 29 PB - Elsevier ER - TY - JOUR A1 - Sýkora, Miroslav A1 - Markova, Jana A1 - Diamantidis, Dimitris T1 - Bayesian network application for the risk assessment of existing energy production units JF - Reliability Engineering & System Safety N2 - The assessment of existing infrastructures in the energy sector is of great economic significance worldwide. Fossil power stations are reaching their design service life and rational decisions concerning extensions of service life, maintenance and replacements of devices should be based on updated information of the actual conditions of the energy devices and their components, and on cost-benefit analysis using risk analysis and probabilistic optimisation procedures. The contribution provides an integrated framework for probabilistic reliability and risk assessment of existing energy production units considering availability and human safety criteria. An extensive case study focused on risks of an energy production unit in a fossil power station is provided to support practical applications. A Bayesian network is thereby implemented to assess the risks of the selected production unit. Special emphasis is given to the input data consisting of failure rates obtained from recorded data and expert judgements. The influence of uncertainties in the considered performance indicators on the availability of the unit is analysed. It is shown that a reasonably simplified framework can provide a valuable assessment of the influence of individual devices and their components on availability and societal risk, identifying thus the major risk contributors. (C) 2017 Elsevier Ltd. All rights reserved. KW - Availability KW - Bayesian networks KW - Decision-making KW - design KW - Failure probability KW - FRAMEWORK KW - Optimization KW - Production unit KW - Risk analysis KW - Societal risk KW - SYSTEMS KW - Uncertainties Y1 - 2018 U6 - https://doi.org/10.1016/j.ress.2017.09.006 VL - 169 IS - January SP - 312 EP - 320 PB - Elsevier ER - TY - JOUR A1 - da Silva Mota, Fabio Antonio A1 - Hinckel, Jose Nivaldo A1 - Rocco, Evandro Marconi A1 - Schlingloff, Hanfried T1 - Trajectory Optimization of Launch Vehicles Using Object-oriented Programming JF - Journal of aerospace technology and management N2 - The aim of this study is to model launch vehicles with focus on 3-DOF trajectory optimization using a modular approach. Despite the large number of operational launch vehicles, they usually consist of basic components and subsystems. In other words, a launch vehicle is an assembly of stages, which in turn is divided into propellant system and engine, and the engine is an assembly of basic components such as pumps, turbines, combustion chamber, and nozzle. To allow future extension and reuse of the codes, a modular structure using object-oriented programming is used. Two formulations of state equations of the trajectory and two optimization methods are described. The launch vehicle performance will be measured by payload mass for a given mission. The simulations of the VLS-1, Ariane 5 and VLS-Alfa were performed and showed good agreement with the literature. KW - Launch vehicle KW - Object-oriented programming KW - Optimization KW - Trajectory Y1 - 2018 U6 - https://doi.org/10.5028/jatm.v10.948 VL - 10 PB - Institute of Aeronautics and Space ER - TY - JOUR A1 - Kurzweil, Peter A1 - Shamonin (Chamonine), Mikhail T1 - State-of-Charge Monitoring by Impedance Spectroscopy during Long-Term Self-Discharge of Supercapacitors and Lithium-Ion Batteries JF - Batteries N2 - Frequency-dependent capacitance C(ω) is a rapid and reliable method for the determination of the state-of-charge (SoC) of electrochemical storage devices. The state-of-the-art of SoC monitoring using impedance spectroscopy is reviewed, and complemented by original 1.5-year long-term electrical impedance measurements of several commercially available supercapacitors. It is found that the kinetics of the self-discharge of supercapacitors comprises at least two characteristic time constants in the range of days and months. The curvature of the Nyquist curve at frequencies above 10 Hz (charge transfer resistance) depends on the available electric charge as well, but it is of little use for applications. Lithium-ion batteries demonstrate a linear correlation between voltage and capacitance as long as overcharge and deep discharge are avoided. KW - aging KW - capacitance KW - self-discharge KW - state-of-charge monitoring KW - supercapacitor Y1 - 2018 U6 - https://doi.org/10.3390/batteries4030035 VL - 4 IS - 3 SP - 1 EP - 13 PB - MPDI ER - TY - JOUR A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris A1 - Holický, Milan A1 - Marková, Jana A1 - Rózsás, Árpád T1 - Assessment of compressive strength of historic masonry using non-destructive and destructive techniques JF - Construction and Building Materials N2 - Masonry structures were built by various techniques using different materials, the properties of which exhibit a considerable scatter dependent on periods of construction and region-specific conditions. For historic structures with a heritage value, various non- or minor-destructive tests (NDTs) are commonly applied, while the application of destructive tests (DTs) is minimized. The contribution is based on investigations of 15 historic stone and clay brick masonry structures, for which NDT strengths of masonry units are verified by DTs. The proposed operational approach makes it possible to account for statistical uncertainty due to a limited number of DTs used to calibrate NDTs. KW - Calibration KW - Clay bricks KW - Compressive strength KW - Mortar KW - Non-destructive test KW - Statistical analysis KW - Stone masonry KW - Uncertainty Y1 - 2018 U6 - https://doi.org/10.1016/j.conbuildmat.2018.10.180 VL - 193 IS - December SP - 196 EP - 210 PB - Elsevier ER - TY - JOUR A1 - Lee, Wai-Kong A1 - Schubert, Martin J. W. A1 - Ooi, Boon Yaik A1 - Ho, Stanley Jian-Qin T1 - Multi-source energy harvesting and storage for floating wireless sensor network nodes with Long Range Communication Capability JF - IEEE Transactions on Industry Applications N2 - Wireless sensor networks are widely used for environmental monitoring in remote areas. They are mainly composed of wireless sensor nodes, usually powered by batteries with limited capacity, but are expected to communicate in long range and operate for extended time periods. To overcome these limitations, many energy harvesting techniques are proposed to power wireless nodes for prolonged operation, whereas multihop techniques are utilized to extend the communication range. In this paper, a novel floating device with multisource energy harvesting technology that can be used as a wireless sensor node is proposed. The long range communication between wireless sensor nodes and a gateway is established through LoRa technology. In addition to conventional solar panels, an energy harvesting technique based on thermoelectric generators exploiting thermal differences created between water surface and materials exposed to sunlight is proposed. Energy generated from photovoltaic and thermoelectric generators is combined to power the wireless sensor node. This floating device consumes 6.6216 Wh per day when used as a wireless sensor node for the collection and transmission of environmental data. The sensor node can operate on a water surface for at least 9.6 days when it is not exposed to sunlight. During a sunny day, the floating device can harvest 8.375 Wh from solar panels and 0.425 Wh from thermoelectric generation. In other words, the floating device harvests sufficient energy to be self-sustaining during sunny days. KW - Wireless sensor networks KW - Energy harvesting KW - floating device KW - LoRa KW - sensor node KW - solar energy KW - thermoelectric generation Y1 - 2018 U6 - https://doi.org/10.1109/TIA.2018.2799 VL - 54 IS - 3 SP - 2606 EP - 2615 PB - IEEE ER - TY - CHAP A1 - Holický, Milan A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav T1 - Effects of Quality Control on Reliability of Reinforced Concrete Structures according to Eurocodes T2 - fib Symposium 2016 : Performance-Based Approaches for Concrete Structures, 14, 2016, Cape town N2 - The effect of quality control on structural reliability represents an increasingly important concern of designers and thus is investigated in this contribution, focusing on reinforced concrete structures. Recent European documents for structural design – Eurocodes, fib Model Code 2010 and ISO 2394:2015 for general principles on structural reliability indicate that the partial factors may be adjusted to available information on the quality control of structures. In particular, the partial factors for concrete and steel strength may be significantly reduced taking into account actual execution quality and related available data. Using probabilistic methods of structural reliability, effects for execution quality are investigated in this contribution considering two fundamental reinforced concrete members: a beam (or slab) exposed to bending and a short column exposed to compression. It is shown that the reliability of reinforced concrete members may vary with the load ratio of variable and permanent actions. It appears also that the structural members of a basic quality, designed using unreduced partial factors, have a greater reliability level than the members of an increased quality, designed using the partial factors reduced according to EN 1992 1 1. This provides the basis for recommendations for further code developments. KW - Eurocodes KW - partial factors KW - quality control KW - reliability Y1 - 2016 UR - https://www.researchgate.net/publication/310616676_Effects_of_quality_control_on_reliability_of_reinforced_concrete_structures_according_to_Eurocodes ER - TY - CHAP A1 - Dessort, Ronnie A1 - Chucholowski, Cornelius A1 - Rill, Georg ED - Bargende, Michael ED - Reuss, Hans-Christian ED - Wiedemann, Jochen T1 - Parametrical approach for modeling of tire forces and torques in TMeasy 5 T2 - Proceedings of the 16. Internationales Stuttgarter Symposium Automobil- und Motorentechnik N2 - For the dynamic simulation of on-road vehicles, the model-element "tire/road" is of special importance, according to its influence on the achievable results. Sufficient description of the interaction between tire and road is one of the most challenging tasks of vehicle modeling. Two groups of tire models can be classified: handling models and structural or high-frequency models. Usually, various assumptions are made in modeling vehicles as multibody systems. Therefore, in the interest of balanced modeling, the precision of the complete vehicle model should stand in reasonable relation to the performance of the applied tire model. Handling tire models are characterized by a useful compromise between user friendliness, model complexity, and efficiency in computation time on the one hand, and precision in representation on the other hand. The present paper describes the general approach of the semi-physical tire model TMeasy for vehicle dynamics and handling simulation and its enhancement for bore torque simulation in Version TMeasy 5. A parameter fitting process realized by TESIS DYNAware and the validation of real tire behavior by simulation with DYNA4 is presented. Even with first guess parameters, the TMeasy tire model behaves in a realistic and plausible manner. Parameter estimation is intuitive and datasets from previous model versions can be easily migrated. After parameter fitting, the simulation results correlate well with both the tire test rig and full vehicle measurements. The enhancement of a three-dimensional slip calculation in the latest version does not modify the model behavior for high slip conditions, but improves the results not only for highly dynamic situations but also for low speed maneuvers such as parking. KW - Drehmoment KW - dynamische Simulation KW - Einparken KW - Fahrzeugdynamik KW - Mehrkörpersystem KW - Parameterabschätzung KW - Rechenzeit KW - REIFENKRAFT KW - Reifentest KW - simuliertes Ergebnis Y1 - 2016 UR - https://www.researchgate.net/publication/317037138_Parametrical_Approach_for_Modeling_of_Tire_Forces_and_Torques_in_TMeasy_5 SN - 978-3-658-13254-5 SP - 435 EP - 449 PB - Springer CY - Wiesbaden ER - TY - JOUR A1 - Ebner, Lena A1 - Elsner, Michael T1 - Thermische Energiespeicher: Wärmespeicherung in Kugelschüttungen. Numerische Simulation der Stromungs-, Warmetransport- und Entstaubungsvorgänge JF - BWK. Das Energie-Fachmagazin N2 - Festbettspeicher bieten die Möglichkeit, thermische Energie auf einem hohen Temperaturniveau zu speichern. Die oft kugelförmigen Schüttgüter bestehen aus Materialien hoher Dichte und Wärmekapazität. Neben der Wärmespeicherung können mithilfe dieser Schüttungen partikelbeladene Abgase entstaubt werden. Die Strömungs-, Wärmetransport- und Entstaubungsvorgänge bei der Speicherung von Wärme in einem Schüttschichtwärmeübertrager werden in Zusammenarbeit mit Fraunhofer Umsicht, Institutsteil Sulzbach-Rosenberg, untersucht. Einen entscheidenden Aspekt der Arbeiten stellt die numerische Simulation der im Wärmeübertrager ablaufenden Vorgänge dar. Die transiente Simulation von Schüttschichtwärmeübertragern ist nur mit Vereinfachungen möglich, da aufgrund der komplexen Geometrie und der daraus folgenden feinen Vernetzung eine enorme Rechenleistung benötigt wird. Bei den in diesem Beitrag vorgestellten Ergebnissen werden die physikalischen Vorgange in einem Ausschnitt der Schüttschicht simuliert, in dem die Kugelgeometrie detailliert modelliert ist. Die Ergebnisse der numerischen Simulation werden durch analytische Berechnungen aus der Literatur bestätigt. Eine Reihe von Parametervariationen zeigen die Einflüsse verschiedener Größen beispielsweise auf den Druckverlust sowie den Unterschied zwischen radialer und axialer Durchströmung einer Schüttschicht. Die Entstaubung partikelbeladener Gase innerhalb einer Schüttschicht wird zunächst anhand einer Einzelkugel untersucht; die Erweiterung auf die Entstaubung in einer Kugelpackung ist vorgesehen. Die Ergebnisse der numerischen Simulationen sollen mit den an einem Versuchsstand experimentell bestimmten Daten verglichen werden. KW - Abgas KW - Druckverlust KW - Durchströmung KW - Entstaubung KW - Festbett KW - hohe Dichte KW - Kugelschüttung KW - numerische Simulation KW - Rechenleistung KW - Schüttgut KW - thermische Energie KW - Wärmekapazität KW - Wärmespeicherung KW - Wärmetransport KW - Wärmeübertrager Y1 - 2014 VL - 66 IS - 9 SP - 40 EP - 43 PB - VDI-Verlag ER -