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 - JOUR A1 - Haug, Sonja A1 - Vetter, Miriam A1 - Weber, Karsten T1 - Gebäudesanierung zwischen Energieeffizienz und Sozialverträglichkeit BT - Zwei empirische Fallstudien JF - TATuP - Zeitschrift für Technikfolgenabschätzung in Theorie und Praxis N2 - Die Akzeptanz unter Bewohnern und Bewohnerinnen gewinnt bei hoch komplexen, technisch anspruchsvollen energetischen Sanierungen als „Innovationsmotor“ zunehmend an Relevanz. Der Beitrag basiert auf zwei Fallstudien zur partizipativen Nutzereinbindung bei energetischen Sanierungen im genossenschaftlichen Wohnbau historischer Stadtquartiere in Regensburg. Neben einer sozialverträglichen Sanierung wurde jeweils ein hohes Maß an Energieeffizienz bei den technischen Lösungen ange-strebt. Haushaltsbefragungen und qualitative Interviews zeigen die hohe Akzeptanz von Sanierungsmaßnahmen, sofern die Senkung der Energiekosten die erhöhte Miete kompensiert. Abschließend werden Akzeptanzfaktoren wie Partizipation, Vertrauen, Sozialverträglichkeit und Autarkie erörtert. T2 - Building restoration between energy efficiency and user acceptance KW - Altbaumodernisierung KW - Energieeinsparung KW - Sozialverträglichkeit KW - Fallstudie KW - energy-efficient building restoration KW - user acceptance KW - household survey KW - historic quarter KW - renewable energy Y1 - 2020 U6 - https://doi.org/10.14512/tatup.29.3.56 SN - 2567-8833 VL - 29 IS - 3 SP - 56 EP - 63 PB - oekom-Verlag ER - TY - CHAP A1 - Weber, Karsten A1 - Haug, Sonja T1 - Automatisiertes Fahren: Evolutionäre Weiterentwicklung statt Disruption T2 - Vierte Jahreskonferenz des Netzwerks INDIGO zum Thema "Mobilität", 23.11.2018, , TH Deggendorf Y1 - 2018 ER - TY - CHAP A1 - De, Sangita A1 - Niklas, Michael A1 - Rooney, Brian A1 - Mottok, Jürgen A1 - Brada, Premek T1 - Towards Translation of Semantics of Automotive Interface Description Models from Franca to AUTOSAR Frameworks BT - An Approach using Semantic Synergies T2 - 2019 International Conference on Applied Electronics (AE), 10-11 Sept. 2019, Pilsen, Czech Republic N2 - The automotive industry is eventually evolving into a complex network of services. The heterogeneous and distributed nature of automotive software systems demands flexible software components which can operate in different environments. Because of heterogeneous automotive development environments, the domain experts, must cope with too many diversities, adaption layers, and incompatibilities to design applications for the current generation of autonomous driving vehicles. In this context, interface adaptation is a promising approach to achieve flexibility without directly changing the respective components. AUTOSAR, which is the de-facto standard for describing automotive system architecture and is a hugely comprehensive standard allowing designers full control from abstract system description to bare metal level deployment. However, the vehicle subsystems have still evolved to include multifarious high-level domains not covered by AUTOSAR e.g. Infotainment, Telematics etc. Therefore, it seems beneficial to bridge the semantic gaps between AUTOSAR applications and other standards of automotive application domains. The goal of this paper is to investigate interface semantic mapping and achieve transparent integration of domain-specific applications using the translation of semantics among the AUTOSAR platform software component models and other software components models of open source development platforms e.g. GENIVI. A key goal of such a modelling approach is the reuse of existing interface description languages and respective code generators. This will enhance future interoperability and decrease in incompatibility among these platforms. KW - Adaptation models KW - ARXML KW - Automotive engineering KW - component model KW - Connectors KW - FRAMEWORK KW - Franca IDL KW - interface KW - Receivers KW - semantic KW - synergy KW - traits Y1 - 2019 U6 - https://doi.org/10.23919/AE.2019.8867018 SP - 1 EP - 6 PB - University of West Bohemia ER - TY - JOUR A1 - Selmair, Maximilian A1 - Maurer, Tobias A1 - Lai, Chun-Han A1 - Grant, David T1 - Enhancing the efficiency of charging & parking processes for Autonomous Mobile Robot fleets BT - A simulative evaluation JF - Journal of Power Sources N2 - The allocation of tasks to Autonomous Mobile Robots in a production setting in combination with the most efficient parking and charging processes are the focus of this paper. This study presents a simulative evaluation of the theoretical allocation methods developed in Selmair and Maurer (2020) combined with either hard or dynamic availability rules to ascertain the most efficient parameters of an Autonomous Mobile Robot System. In order to quantify this efficiency, the following Key Performance Indicator (KPI) were considered: number of delayed orders, driven fleet metres and the percentage of available Autonomous Mobile Robot as determined by their state of charge. Additionally, as an alternative energy source, a fast-charging battery developed by Battery Streak Inc. was included in this study. The results show that, in comparison to a conventional and commonly used trivial strategy, our developed strategies provide superior results in terms of the relevant KPI. KW - AMR KW - Autonomous Mobile Robot KW - Battery charging KW - Battery management systems KW - Benchmarking KW - Fleet operations KW - Mobile robots KW - NAVIGATION KW - Secondary batteries KW - Vehicle Fleet Charging Y1 - 2022 U6 - https://doi.org/10.1016/j.jpowsour.2021.230894 VL - 521 IS - 3 PB - Elsevier ER - TY - CHAP A1 - Jupke, Michael A1 - Reindl, Andrea A1 - Meier, Hans A1 - Niemetz, Michael ED - Pinker, Jiří T1 - Bidirectional DC-DC Converter with Digital Droop Parameterization T2 - 26th 2021 International Conference on Applied Electronics (AE): 7-8 Sept. 2021 Pilsen, Czech Republic N2 - The key for decentralized battery systems is a robust and communication-less control strategy for autonomous power sharing of parallel-connected DC-DC converters. Battery systems improve the reliability and quality of power supply in renewable energy systems and enable power supply for off-grid, mobile applications, including islanded grids, home storage, and electric vehicles. In many cases, components with different electrical properties require different voltage levels. An adaptation is consequently essential and is normally implemented in DC grids for the batteries via bidirectional DC-DC converters. The power flow in both directions can thus be ensured. To achieve a power distribution in parallel connected DC-DC converters, a droop control in the form of a virtual internal resistor can be used. This paper presents a novel approach of a DC-DC converter with a digitally parameterizable droop resistor, whose voltage regulation is based on an analog operational amplifier circuit to ensure low delays and robustness. The droop resistor is adjusted with a microcontroller, which offers the possibility to apply a higher-level control for load sharing via an interface. Mathematical correlations are used to clearly define the parameters of the control. Furthermore, the circuit was completely simulated and tested in the hardware setup. The shown results verify the functionality and indicate only minor deviations. Therefore, this circuit is important for future use in distributed battery systems. KW - battery storage plants KW - DC-DC power convertors KW - power convertors KW - distributed power generation KW - microcontrollers KW - voltage regulators KW - voltage control KW - power generation control KW - power grids Y1 - 2021 SN - 978-80-261-0972-3 U6 - https://doi.org/10.23919/AE51540.2021.9542920 SP - 1 EP - 6 PB - Institute of Electrical and Electronics Engineers ER - TY - CHAP A1 - Boccara, R. A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav T1 - Optimal design of ground-mounted solar systems T2 - Safety and reliability : methodology and applications : proceedings of the European Safety and Reliability Conference, ESREL 2014, Wrocław, Poland, 14-18 September 2014 N2 - Solar energy represents a clean, natural and sustainable source of energy. Solar photovoltaic panels can be installed on roofs of structures or in the ground. This contribution focusses on ground-mounted systems, which are presently widely implemented. At present limited guidelines on the design of solar ground-mounted structures are available. Usually standards for the design of normal buildings are applied. However, the design of ground-mounted structures significantly differs from common structural design by: (1) a lower design lifetime (20-25 years) is accepted; (2) failure is not associated with the loss of human life; (3) resistance uncertainties need due attention; (4) uplift wind forces dominating structural reliability are associated with a large scatter. That is why the reliability analysis and optimal design of ground-mounted solar systems is investigated herein. The failure costs and especially their ratio to the initial costs are analyzed considering the data provided from the industry. Probabilistic reliability analyses are carried out and optimum design levels are computed for representative cost ratios. The optimal target reliability depends on the ratio between failure and initial costs; reliability index of 3.5 corresponds to a reasonable cost ratio of 10. KW - Dach KW - Montagesystem KW - Montiergerät KW - nachhaltiges Sourcing KW - Solarenergie KW - Solarmodul KW - Windkraft (Energiequelle) Y1 - 2014 SN - 978-1-138-02681-0 SP - 2175 EP - 2181 PB - CRC Press CY - Boca Raton ER - TY - CHAP A1 - Kaspar, Marcel A1 - Kleiner, Florian A1 - Rabl, Hans-Peter T1 - Online-Analyse und Optimierung der Schmierölverdünnung bei direkteinspritzenden Ottomotoren T2 - 7. VDI-Fachtagung mit Fachausstellung Zylinderlaufbahn, Kolben, Pleuel : Baden-Baden, 03. und 04. Juni 2014 N2 - Bei Ottomotoren mit Direkteinspritzung besteht beim Kaltstart, den Warmlaufphasen und auch durch den Einfluss anderer Parameter wie z. B. des Einspritzzeitpunkts oder des Einspritzdrucks die Problematik, dass Kraftstoff an die Zylinderlaufbahn aufgetragen wird und sich mit dem Motoröl vermischen kann. Eine Verstärkung dieses Kraftstoffauftrags ist unter anderem der Verschiebung der Motorbetriebspunkte zu höheren Mitteldrücken und damit einem Wirkungsgrad optimaleren Betrieb geschuldet. Eine Veränderung der physikalischen und chemischen Eigenschaften des Motoröls durch die Verdünnung mit Kraftstoff ist die Folge. Durch die Verringerung der Viskosität des Motoröls kann es zu einer verminderten Schmierwirkung des Öls kommen, die im schlimmsten Fall zur Schädigung des Motors führt. Existierende Offline-Analysemethoden die zeitintensive Laboranalysen nach sich ziehen, als auch Online-Messverfahren die nicht den technischen Anforderungen hinsichtlich Genauigkeit und einer kurzen Messdauer entsprechen, stellen aktuell die einzigen Messmethoden zur Bestimmung der Schmierölverdünnung dar. Durch neue Entwicklungstrends bei Ottomotoren ist es jedoch unbedingt notwendig, die Mechanismen des Kraftstoffein- und -austrags in das und aus dem Motoröl genauer zu untersuchen. Mit der an der OTH Regensburg neu entwickelten Messtechnik wurde eine Vorgehensweise erarbeitet, mit der die zeitlichen Verläufe des Kraftstoffein- und -austragsverhaltens bei Ottomotoren quantitativ in kurzer Zeit bestimmt und optimiert werden können. Especially at cold start and the warm-up operation GDI engines have an issue with oil dilution. Parameters such as injection timing and injection pressure impact the entry of fuel in the engine oil as well. With the adjustment of engine operating points to higher mean effective pressures resulting in downsizing concepts also an additional increase of fuel entry occurs. Fuel gets into the oil pan and is mixed with the engine oil so that the physical and chemical properties of the engine oil are changed. With the reduction of engine oil viscosity due to fuel entry a reduced lubricating effect can be caused. In the worst case damage to the engine occurs, To determine oil dilution online and offline measurement methods exist. A rather long analysis time in the laboratory is a disadvantage of the offline methods. Online methods are not correlating with technical requirements in terms of accuracy and a short measurement time. New trends in the development of gasoline engines require investigations of fuel in oil sorption and desorption processes. A new measurement technique which is developed at the OTH Regensburg enables to determine quantitative fuel in oil sorption and desorption processes. With this technique a procedure was generated to measure the oil dilution at gasoline engines and optimize them in a short time. KW - Direkteinspritzerottomotor KW - Direkteinspritzung KW - Kaltstart KW - Kraftstoff KW - Motoröl KW - Online-Analyse KW - Online-Messverfahren KW - Ottomotor KW - Viskositätsverringerung Y1 - 2014 SN - 978-3-18-092230-0 SP - 65 EP - 77 PB - VDI-Verlag CY - Düsseldorf ER - TY - JOUR A1 - Keim, Vincent A1 - Marx, P. A1 - Nonn, Aida A1 - Münstermann, Sebastian T1 - Fluid-structure-interaction modeling of dynamic fracture propagation in pipelines transporting natural gases and CO2-mixtures JF - International Journal of Pressure Vessels and Piping N2 - As part of current design standards, the Battelle Two-Curve Model (BTCM) is still widely used to predict and secure ductile crack arrest in gas transmission pipelines. For modern linepipe steels and rich natural gases or CO2 mixtures, the BTCM might lead to incorrect predictions. On the one hand, it suffers from the insufficient description of the individual physical processes in the pipe material and fluid itself. Furthermore, the model does not account for fluid-structure-interaction (FSI) effects during simultaneous running-ductile fracture (RDF) and mixture decompression. Numerical FSI models allow for a more sophisticated, coupled analysis of the driving forces for the failure of pipelines. This paper deals with the development of an FSI model for the coupled prediction of 3D pressure profiles acting on the inner pipe wall during crack propagation. The coupled Euler-Lagrange (CEL) method is used to link the fluid and structure models. In a Lagrange formulation, the modified Bai-Wierzbicki (MBW) model describes the plastic deformation and ductile fracture as a function of the underlying stress/strain conditions. The fluid behavior is calculated in a 3D model space by Euler equations and the GERG-2008 reference equation of state (EOS). The coupled CEL model is used to predict the RDF in small-diameter pipe sections for different fluid mixtures. The calculated 3D pressure distributions ahead and behind the running crack tip (CT) significantly differ in axial and circumferential directions depending on the mixture composition. The predicted FSI between the pipe wall and fluid decompression in 3D CEL/FSI model provides reliable knowledge about the pressure loading of the pipeline during RDF. KW - Fluid-Struktur-Wechselwirkung KW - Rissausbreitung KW - Pipeline KW - Gas KW - Pipeline failure KW - Fluid-structure-interaction KW - CO2 decompression KW - Running ductile fracture Y1 - 2019 U6 - https://doi.org/10.1016/j.ijpvp.2019.103934 VL - 175 IS - August PB - Elsevier ER - TY - JOUR A1 - Keim, Vincent A1 - Nonn, Aida A1 - Münstermann, Sebastian T1 - Application of the modified Bai-Wierzbicki model for the prediction of ductile fracture in pipelines JF - International Journal of Pressure Vessels and Piping N2 - The complex mechanical and corrosive loads of modern pipeline systems transporting oil, natural gas and CO2 impose steadily increasing requirements on material properties. The majority of current design standards still limit the application of modern high toughness linepipe steels due to the simple specification of material requirements in terms of energy levels from Charpy impact or Battelle Drop-Weight-Tear (BDWT) tests. In consequence, research activities have been conducted recently aiming at developing modified or novel experimental methods for the characterization of the ductile fracture behavior. To quantify the effects of various parameters on fracture behavior and derive suitable correlations, it is necessary to accompany these activities by numerical simulations with appropriate ductile damage models. In this paper, the MBW model is applied to study the structural behavior of pipelines in ductile fracture regime. Due to its precise incorporation of the underlying load conditions, the damage model is successfully used to simulate the slant fracture behavior in Battelle Drop weight tear test specimens and pipe sections. In comparison to ductile damage models applied in former studies, namely the Gurson-Tvergaard-Needleman and Cohesive Zone model, the presented numerical methodology allows for a more detailed investigation of loading, material and geometry effects on fracture and crack arrest behavior of pipelines. KW - Running ductile fracture KW - Stress state conditions KW - MBW model KW - Pipeline failure KW - Slant fracture Y1 - 2019 U6 - https://doi.org/10.1016/j.ijpvp.2019.02.010 VL - 171 IS - March SP - 104 EP - 116 PB - Elsevier ER - TY - CHAP A1 - Reindl, Andrea A1 - Meier, Hans A1 - Niemetz, Michael ED - Brinkmann, André ED - Karl, Wolfgang ED - Lankes, Stefan ED - Tomforde, Sven ED - Pionteck, Thilo ED - Trinitis, Carsten T1 - Scalable, Decentralized Battery Management System Based on Self-organizing Nodes T2 - Architecture of computing systems - ARCS 2020: 33rd international conference, Aachen, Germany, May 25-28, 2020, proceedings N2 - Due to the transition to renewable energy sources and the increasing share of electric vehicles and smart grids, batteries are gaining in importance. Battery management systems (BMSs) are required for optimal, reliable operation. In this paper, existing BMS topologies are presented and evaluated in terms of reliability, scalability and flexibility. The decentralisation of BMSs and associated advantages are shown. A scalable, reconfigurable BMS based on a distributed architecture of self-organized, locally controlled nodes is proposed. For distributed system control, producers, batteries and consumers each are equipped with a local microcontroller based control unit, which monitors and controls the local parameters with its own computing and communication resources. Features, advantages and challenges to overcome of the proposed approach are described. KW - Availability Decentralized control KW - Battery management systems KW - Controller Area Network KW - distributed management KW - fault tolerant control KW - Multi-microcomputer system KW - Reconfigurable architectures KW - Renewable energy sources KW - Scalability KW - Topology Y1 - 2020 SN - 978-3-030-52793-8 U6 - https://doi.org/10.1007/978-3-030-52794-5_13 VL - 12155 SP - 171 EP - 184 PB - Springer International Publishing CY - Cham ER - TY - CHAP A1 - Völling, Alexander A1 - Nonn, Aida A1 - Schneider, Ingo T1 - Anwendung des Kohäsivzonenmodells zur Abbildung von duktilem dynamischen Rissfortschritt in Gasfernleitungen T2 - 45. Tagung des AK Bruch, Berlin, Germany KW - Ferngasleitung KW - Rissfortschritt Y1 - 2013 SP - 253 EP - 262 ER - TY - JOUR A1 - Mikhaeil, Makram A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - Experimental Investigation of the Adsorption and Desorption Kinetics on an Open-Structured Asymmetric Plate Heat Exchanger; Matching Between Small-Scale and Full-Scale Results JF - Frontiers in Energy Research N2 - This paper introduces the results of an experimental study on the adsorption and desorption kinetics of a commercially available, open-structured asymmetric plate heat exchanger adapted to act as an adsorber/desorber for the application in adsorption heat transformation processes. In addition, a volumetric large temperature jump (V-LTJ) kinetic setup was applied to measure the adsorption and desorption kinetics of a small-scale adsorbent sample prepared dedicatedly to be representative for the adsorbent domain inside the investigated adsorber plate heat exchanger (APHE). All kinetic results of the small-scale adsorbent sample and the APHE were fitted into exponential forms with a single characteristic time constant (τ) with a coefficient of determination (R2) better than 0.9531. A very good matching between the small-scale and full-scale adsorption kinetic measurements was obtained, with an average relative deviation of 12.3% in the obtained τ-values. In addition, the kinetic data of the small-scale adsorbent sample were utilized for estimating the expected specific instantaneous and moving average powers of the evaporator/condenser heat exchanger. The average relative deviation (ARD) between the moving average specific evaporator powers obtained from the small-scale and the full-scale measurements amounts between 5.4 and 15.1%. Y1 - 2022 U6 - https://doi.org/10.3389/fenrg.2022.818486 N1 - Corresponding author: Belal Dawoud VL - 10 SP - 1 EP - 15 PB - Frontiers ER - TY - CHAP A1 - Arrieta Castro, Abel A1 - Weber, Hans Ingo A1 - Rill, Georg T1 - Design an integrate vehicle control based-on hierarchical architecture for improve the performance of ground vehicles T2 - COBEM2015 : 23rd ABCM International Congress of Mechanical Engineering, December 6-11, 2015, Rio de Janeiro, RJ, Brazi Y1 - 2015 U6 - https://doi.org/10.20906/cps/cob-2015-1970 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 - Monkman, Gareth J. A1 - Sindersberger, Dirk A1 - Prem, Nina A1 - Diermeier, Andreas A1 - Szecsey, Tamara T1 - Dielectric behaviour of magnetic hybrid materials JF - Physical Sciences Reviews N2 - The objectives of this work include the analysis of electrical and magnetic properties of magneto-elastic hybrid materials with the intention of developing new techniques for sensor and actuator applications. This includes the investigation of dielectric properties at both low and high frequencies. The behaviour of capacitors whose dielectrics comprise magnetic hybrid materials is well known. Such interfacial magnetocapacitance can be varied according to magnetic content, magnetic flux density and the relative permittivity of the polymer matrix together with other dielectric content. The basic function of trapping electrical charges in polymers (electrets) is also established technology. However, the combination of magnetoactive polymers and electrets has led to the first electromagnetic device capable of adhering to almost any material, whether magnetically susceptible or not. During the course of this research, in addition to dielectrics, electrically conductive polymers based on (PDMS) matrices were developed in order to vary the electrical properties of the material in a targeted manner. In order to ensure repeatable results, this demanded new fabrication techniques hitherto unavailable. The 3D printing of silicones is far from being a mature technology and much pioneering work was necessary before extending the usual 3 d.o.f. to include orientation about and diffusion of particles in these three axes, thus leading to the concept of 6D printing. In 6D printing, the application of a magnetic field can be used during the curing process to control the particulate distribution and thus the spatial filler particle density as desired. Most of the devices (sensors and actuators) produced by such methods contain levels of carbonyl iron powder (CIP) embedded magnetic filler of up to 70 wt%. Contrary to this, a hitherto neglected research area, namely magnetoactive polymers (MAPs) having significantly lower magnetic particle concentrations (1 to 3 wt% CIP) were also investigated. With filler concentrations lower than 3 wt%, structures are formed which are completely absent at higher filler levels. CIP concentrations in the range of 1wt% demonstrate the formation of toroidal structures. Further development of coherent rings with a compact order results as filler concentrations increase towards 2 wt%. Above 3 wt% the structure eventually disintegrates to the usual random order found in traditional MAP with higher CIP content. Structured samples containing 1%–3 wt% CIP were investigated with the aid of X-ray tomography where solitary ring structures can be observed and eventually the formation of capillary doubles. Over wavelengths ranging from 1 to 25 µm, spectroscopic analysis of thin film MAP samples containing 2 wt% CIP revealed measurable magnetic-field-dependent changes in IR absorption at a wavenumber 2350 (λ = 4.255 µm). This was found to be due to the diamagnetic susceptibility of atmospheric carbon dioxide (CO2). Consequently, the first potential application for sparse matrix MAPs was found. KW - cappillary doublet KW - diamagnetic KW - elastomer dielectric KW - FTIR KW - interfacial magnetocapacitance KW - magnetoactive polymer KW - PDMS KW - toroid Y1 - 2021 U6 - https://doi.org/10.1515/psr-2019-0121 N1 - Corresponding author: Gareth J. Monkman VL - 7 IS - 10 SP - 1169 EP - 1185 PB - de Gruyter ER - TY - CHAP A1 - Grimm, Alexander A1 - Haumer, Anton T1 - EMOTH The EMobility Library of OTH Regensburg T2 - Proceedings of the 12th International Modelica Conference, Prague, Czech Republic, May 15-17, 2017 N2 - The importance of E-Mobility is rapidly increasing, not only for private vehicle traffic but also for public transport. In and around Regensburg, Germany there are a lot of automotive companies. Therefore E-Mobility is an important topic in the curriculum of several courses of study at the East-Bavarian Technical University of Applied Sciences Regensburg (OTH). One Master of Applied Research student at OTH has chosen the topic to develop an open-source simulation tool for electric vehicles – the EMOTH Library – based on Modelica and to refine several aspects of the library during the one and a half year of the master course. After one semester, the basic version of the library is available and will be presented in this paper. Y1 - 2017 U6 - https://doi.org/10.3384/ecp17132285 SP - 285 EP - 290 PB - Linköping University Electronic Press ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav T1 - Implementing Information Gained through Structural Health Monitoring – Proposal for Standards T2 - 13th International Conference on Applications of Statistics and Probability in Civil Engineering, Mai 2019, Seoul, Korea N2 - With exception of a few issues such as design by testing, current standards do not include guidelines on the use and the quantification of value of additional information gained through Structural Health Monitoring (SHM). This contribution summarizes a recently developed draft of the guideline for practicing engineers in the framework of the EU-COST project 1402 and illustrates its application in engineering decision-making. Besides continuous and periodic monitoring, visual inspection, non-destructive evaluation and proof loading are included herein as a simple form of SHM. The guideline is independent of a type of structure, construction materials, loading, and of environmental conditions. It aims at a wide field of application including design of new structures, assessment of existing structures and type specific monitoring of a population of structures. The decision process related to the use of SHM is presented first together with relevant decision objectives and variables. Performance indicators are summarized and discussed with respect to the performance objectives. The evaluation of monitoring strategies based on life cycle costs is exposed and the selection of optimal intervention actions including safety measures is shown in representative case studies. The results demonstrate the potential of the use of monitoring to support engineering decisions and reflect though the practical benefits from the application of the guideline. Y1 - 2019 UR - https://www.researchgate.net/publication/333578633_Implementing_Information_Gained_through_Structural_Health_Monitoring_-Proposal_for_Standards ER - TY - JOUR A1 - Gamisch, Bernd A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - On the Development of Thermochemical Hydrogen Storage: An Experimental Study of the Kinetics of the Redox Reactions under Different Operating Conditions JF - Applied Sciences N2 - This work aims at investigating the reduction/oxidation (redox) reaction kinetics on iron oxide pellets under different operating conditions of thermochemical hydrogen storage. In order to reduce the iron oxide pellets (90% Fe2O3, 10% stabilizing cement), hydrogen (H2) is applied in different concentrations with nitrogen (N2), as a carrier gas, at temperatures between between 700 ∘C and 900 ∘C, thus simulating the charging phase. The discharge phase is triggered by the flow of a mixture out of steam (H2O) and N2 at different concentrations in the same temperature range, resulting in the oxidizing of the previously reduced pellets. All investigations were carried out in a thermo-gravimetric analyzer (TGA) with a flow rate of 250mL/min. To describe the obtained kinetic results, a simplified analytical model, based on the linear driving force model, was developed. The investigated iron oxide pellets showed a stable redox performance of 23.8% weight reduction/gain, which corresponds to a volumetric storage density of 2.8kWh/(L bulk), also after the 29 performed redox cycles. Recalling that there is no H2 stored during the storage phase but iron, the introduced hydrogen storage technology is deemed very promising for applications in urban areas as day-night or seasonal storage for green hydrogen. KW - hydrogen storage KW - iron/iron oxide KW - reaction kinetics KW - redox reactions Y1 - 2021 U6 - https://doi.org/10.3390/app11041623 N1 - Corresponding author: Belal Dawoud VL - 11 IS - 4 SP - 1 EP - 15 PB - MDPI CY - Basel ER - TY - JOUR A1 - Dechant, Eduard A1 - Fedulov, Feodor A1 - Fetisov, Leonid Y. A1 - Shamonin (Chamonine), Mikhail T1 - Bandwidth Widening of Piezoelectric Cantilever Beam Arrays by Mass-Tip Tuning for Low-Frequency Vibration Energy Harvesting JF - Applied Science N2 - Wireless sensor networks usually rely on internal permanent or rechargeable batteries as a power supply, causing high maintenance efforts. An alternative solution is to supply the entire system by harvesting the ambient energy, for example, by transducing ambient vibrations into electric energy by virtue of the piezoelectric effect. The purpose of this paper is to present a simple engineering approach for the bandwidth optimization of vibration energy harvesting systems comprising multiple piezoelectric cantilevers (PECs). The frequency tuning of a particular cantilever is achieved by changing the tip mass. It is shown that the bandwidth enhancement by mass tuning is limited and requires several PECs with close resonance frequencies. At a fixed frequency detuning between subsequent PECs, the achievable bandwidth shows a saturation behavior as a function of the number of cantilevers used. Since the resonance frequency of each PEC is different, the output voltages at a particular excitation frequency have different amplitudes and phases. A simple power-transfer circuit where several PECs with an individual full wave bridge rectifier are connected in parallel allows one to extract the electrical power close to the theoretical maximum excluding the diode losses. The experiments performed on two- and three-PEC arrays show reasonable agreement with simulations and demonstrate that this power-transfer circuit additionally influences the frequency dependence of the harvested electrical power. KW - array KW - BAND-PASS FILTERS KW - bandwidth KW - BIMORPH KW - Optimization KW - OUTPUT KW - PERFORMANCE KW - piezoelectric cantilever KW - POWER KW - vibration energy harvesting Y1 - 2017 U6 - https://doi.org/10.3390/app7121324 N1 - Corresponding Author: Mikhail Shamonin VL - 7 IS - 12 PB - MDPI 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 - Huber, Lea A1 - Heindl, Melanie A1 - Schlosser, Marc A1 - Pfitzner, Arno A1 - Dawoud, Belal T1 - On the Cycle Stability and Macroscopic Structure of Iron Oxide Pellets for Thermochemical Hydrogen Storage: Influence of Water Content during the Pelletizing Process JF - Applied Sciences N2 - Hydrogen storage based on the repeated reduction and oxidation (redox) reactions of iron oxide/iron composites represents a promising technology. This work is dedicated to studying the influence of the amount of water added during the pelletizing process on the cycle stability and structure of iron oxide pellets. The storage composites were prepared from iron oxide (Fe2O3) and 10 wt.-% support material (cement) with different amounts of water (18 and 33 wt.-%) in a laboratory-scale pelletizing disk. To evaluate the cycle stability of the composites, the kinetics of the redox reactions were experimentally measured at 800 ∘ C in an atmosphere of 50% N2 and 50% H2 (reduction) or 50% steam (oxidation), respectively. Moreover, the structure of the pellets was analyzed by micro-computed tomography scans. It turned out that pellets with higher water contents attained faster kinetics and a higher cycle stability. The sample with the least water content (18 wt.-%) needed about 26 min and 19 min to reach a conversion rate of 80% during the reduction and oxidation reactions of the sixth redox cycle, respectively. In contrast, the sample with the highest water content (33 wt.-%) could achieve the same conversion rate after 18 min (reduction) and 13 min (oxidation) during the ninth redox cycle. KW - hydrogen storage KW - redox reactions KW - iron/iron oxide KW - pelletizing process KW - cycle stability KW - water content Y1 - 2023 U6 - https://doi.org/10.3390/app13116408 N1 - Corresponding author: Belal Dawoud VL - 13 IS - 11 PB - MDPI CY - 16 ER - TY - JOUR A1 - Steininger, Peter A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - Assessment of the Annual Transmission Heat Loss Reduction of a Refurbished Existing Building with an Advanced Solar Selective Thermal Insulation System JF - Sustainability N2 - A numerical parameter sensitivity analysis of the design parameters of the recently published solar selective thermal insulation system (SATIS) has been carried out to enhance its thermal and optical properties. It turned out that the insulation properties of SATIS can be effectively improved by reducing the length of the glass closure element. Increasing the area share of the light conducting elements (LCEs) and decreasing their length-to-diameter (L/D) ratio were identified as key parameters in order to increase the solar gain. Two SATIS variants were compared with the same wall insulation without SATIS in a yearly energetic performance assessment. The SATIS variant with 10 mm length of the closure element, 44.2% area share of LCE, as well as front and rear diameters of 12 mm/9 mm shows an 11.8% lower transmission heat loss over the heating period than the wall insulation without SATIS. A new methodology was developed to enable the implementation of the computed solar gains of SATIS in 1D simulation tools. The result is a radiant heat flow map for integration as a heat source in 1D simulation models. A comparison between the 1D and 3D models of the inside wall heat fluxes showed an integral yearly agreement of 98%. KW - effective thermal conductivity KW - parameter sensitivity analysis KW - radiant heat flow map KW - solar selective thermal insulation system (SATIS) KW - total solar energy transmittance KW - yearly energetic performance assessment Y1 - 2021 U6 - https://doi.org/10.3390/su13137336 N1 - Corresponding author: Belal Dawoud VL - 13 IS - 13 SP - 1 EP - 19 PB - MDPI CY - Basel ER - TY - JOUR A1 - Bringout, Gaël A1 - Erb, Wolfgang A1 - Frikel, Jürgen T1 - A new 3D model for Magnetic Particle Imaging using realistic magnetic field topologies for algebraic reconstruction JF - Inverse Problems N2 - We derive a new 3D model for magnetic particle imaging (MPI) that is able to incorporate realistic magnetic fields in the reconstruction process. In real MPI scanners, the generated magnetic fields have distortions that lead to deformed magnetic low-field volumes with the shapes of ellipsoids or bananas instead of ideal field-free points (FFP) or lines (FFL), respectively. Most of the common model-based reconstruction schemes in MPI use however the idealized assumption of an ideal FFP or FFL topology and, thus, generate artifacts in the reconstruction. Our model-based approach is able to deal with these distortions and can generally be applied to dynamic magnetic fields that are approximately parallel to their velocity field. We show how this new 3D model can be discretized and inverted algebraically in order to recover the magnetic particle concentration. To model and describe the magnetic fields, we use decompositions of the fields in spherical harmonics. We complement the description of the new model with several simulations and experiments, exploring the effects of magnetic fields distortion and reconstruction parameters on the reconstruction. Y1 - 2020 U6 - https://doi.org/10.1088/1361-6420/abb446 VL - 36 IS - 12 PB - IOP Publishing 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 - Dawoud, Belal T1 - An alternative approach towards absorption heat pump working pair screening JF - Renewable Energy N2 - The successful market penetration of modern absorption heat pumps (AHP) today is critically dependent on their thermodynamic performance as well as other key factors like cost, reliability and inherent safety. Conventional AHPs have a proven record in the first two aspects but crucial shortcomings in the last two. For this reason it has been imperative to search for alternative working pairs that could potentially provide comparable performance while also satisfying the rest of the conditions to the best extent possible. As part of a systematic approach towards this direction, a detailed cycle analysis was performed, utilizing an idealized AHP system containing a real working pair, which enabled the identification of five dimensionless parameters and key thermophysical properties that influence the system's thermodynamic efficiency and the circulation ratio. In order to validate those findings, these parameters were calculated and compared between conventional and alternative AHP refrigerants. It turned out that low molecular weight ratios between absorbent and refrigerant have a beneficial effect on both coefficient of performance and the circulation ratio. Furthermore, both the refrigerant acentric factor and the absorbent vaporization enthalpy shall be minimized to obtain better performance. (C) 2016 Elsevier Ltd. All rights reserved. KW - Absorption heat pump KW - Coefficient of performance KW - FLUIDS KW - Working pair Y1 - 2017 U6 - https://doi.org/10.1016/j.renene.2016.08.014 VL - 110 SP - 47 EP - 58 PB - Pergamon-Elsevier ER - TY - CHAP A1 - Kraus, Hermann A1 - Brückl, Oliver T1 - Automated use of wired measures in grid planning for solving current and voltage band problems T2 - Power and Energy Student Summit (PESS) 2019, Magdeburg N2 - This work deals with the use of cable exchange and parallel cabling as network expansion measures in the context of an automated grid planning for the elimination of current and voltage band problems in a distribution network. Inter alia, reference is made to a higher-level program, which is being developed in the EU project "CrossEnergy", and the procedures for remedying the limit value violations are presented. KW - Netzplanung KW - Automatisierung KW - Netzverstärkung KW - Leitungsmaßnahme Y1 - 2019 SN - 978-3-944722-84-9 U6 - https://doi.org/10.24352/UB.OVGU-2019-086 VL - 77 SP - 207 EP - 211 PB - Otto-von-Guericke-Universität, Institut für Elektrische Energiesysteme CY - Magdeburg ER - TY - CHAP A1 - Miedl, Christian A1 - Braun, Jürgen T1 - Powertrain and electric system design of a 800-volt all-electric car T2 - European Conference on Nanoelectronics and Embedded Systems for Electric Mobility, eMotion in Smart Cities, 24.-28. September, 2012, Bologna, Italy Y1 - 2012 ER - TY - JOUR A1 - Ostermeier, Daniel A1 - Mottok, Jürgen A1 - Knorr, Christine A1 - Huber, Michael ED - Mottok, Jürgen ED - Ziemann, Olaf T1 - Competence Atlas for Save and Green Road Vehicles in the Electro Mobility Cluster Regensburg JF - Applied Research Conference 2012 (ARC 2012) 25./26. June 2012, Nuremberg Y1 - 2012 SP - 86 EP - 92 ER - TY - CHAP A1 - Mottok, Jürgen T1 - Migration path for secure and economic smart power grid devices with transitional smart metering support T2 - 2nd Applied Research Conference 2012 (ARC 2012), 25./26. June 2012, Nuremberg Y1 - 2012 SP - 64 EP - 70 ER - TY - CHAP A1 - Nick, Matthias A1 - Schorer, Michael A1 - Mottok, Jürgen ED - Mottok, Jürgen ED - Ziemann, Olaf T1 - Feasibility Study of a Build System Performing Automated Builds Based on Model-Based Build Descriptions T2 - 2nd Applied Research Conference 2012 (ARC 2012), 25./26. June 2012, Nuremberg Y1 - 2012 SP - 71 EP - 75 PB - Shaker CY - Aachen ER - TY - CHAP A1 - Sailer, Andreas A1 - Deubzer, Michael A1 - Lüttgen, Gerald A1 - Mottok, Jürgen T1 - Comparing Trace Recordings of Automotive Realtime Software T2 - RTNS '17: Proceedings of the 25th International Conference on Real-Time Networks and Systems, Grenoble, France, IEEE N2 - The process of engineering models of existing real-time system components is often difficult and time consuming, especially when legacy code has to be re-used or information about the exact timing behaviour is needed. In order to tackle this reverse engineering problem, we have developed the tool CoreTAna. CoreTAna derives an AUTOSAR compliant model of a real-time system by conducting dynamic analysis using trace recordings. Motivated by the challenge of assessing the quality of reverse engineered models of real-time software, we present a novel mathematical measure for comparing trace recordings from embedded real-time systems regarding their temporal behaviour. We also introduce a benchmark framework based on this measure, for evaluating reverse engineering tools such as CoreTAna. This considers common system architectures and also includes randomly generated systems and three systems of industrial automotive projects. Finally, an industrial case study demonstrates other use cases of our measure, such as impact analysis. Y1 - 2017 U6 - https://doi.org/10.1145/3139258.3139265 SP - 118 EP - 127 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 - CHAP A1 - Nonn, Aida A1 - Kalwa, Christoph T1 - Analysis of dynamic ductile fracture propagation in pipeline steels BT - a damage mechanics approach T2 - 6th Pipeline Technology Conference (2013), Ostend, Belgium N2 - Analysis of dynamic ductile fracture propagation in pipeline steels: a damage-T IS A WELL-ESTABLISHED fact that the successful application of new generation of high-strength steel grades for long-distance gas transmission depends strongly on full understanding and appropriate characterization of fracture resistance. A damage mechanics approach has found to be a very promising tool in supporting the experimental characterization of ductile fracture propagation. The major advantage of this approach lies in the consideration of the influence of local stress and strain variables on the damage evolution and thus its capability to describe the fracture resistance of the pipelines with different stress triaxiality level by using the same set of parameters. However, the wider application of this approach has been limited due to the issues such as reliable determination of input parameters and required material properties, mesh size dependence, etc.. The objective of this paper is to characterize dynamic ductile fracture resistance of X65 and X80 pipeline materials and to demonstrate the potential of damage mechanics approach for the simulation of dynamic fracture propagation by using two damage models: (1) Cohesive Zone (CZ) model and (2) Gurson-Tvergaard-Needleman (GTN) model. In the first step, results from quasi-static and dynamic tensile tests are used to describe plasticity in terms of flow curves. The calibration of input parameters for both models is performed by using the load-deformation curves from quasi-static tests on non-standard drop-weight tear (DWT) specimens with pre-fatigued crack. b. In the next step, estimated damage model parameters are verified by means of the dynamic tests on the pressed and Chevron notch DWT specimens. Different amounts of crack growth are established by varying the drop height. The experimental fracture resistance is quantified in terms of J-integral at specific crack length. The numerical results are evaluated with respect to global load-deformation and fracture resistance behavior. Furthermore, damage simulations are applied for quantification of local stress conditions in order to identify the major factors controlling the crack propagation. The results reported here serve as a basis for better understanding of fracture performance in dependences of geometry and material properties. Y1 - 2013 U6 - https://doi.org/10.13140/2.1.4370.3046 ER - TY - CHAP A1 - Nonn, Aida A1 - Kalwa, Christoph T1 - Failure modeling of pipeline X100 Material in temperature transition region T2 - 22nd International Society of Offshore and Polar Engineering 2012 (ISOPE 2012), Rhodes, Greece N2 - This paper focuses on the characterization of the fracture performance of X100 material in transition temperature region using both experimental and numerical methods. The ductile fracture has been analyzed using tests on round notched bar specimens and standard fracture mechanics tests performed at room temperature. In previous publications the damage model Gurson-Tvergaard-Needleman (GTN) has been applied and verified by existing experimental data to describe ductile fracture behavior. The brittle fracture and the fracture in temperature transition region have been studied by means of deep and shallow notched SENB specimens at two different temperatures T=- 80°C and -40°C. Besides elastic-plastic analyses to quantify constraint levels for different initial crack configurations at the onset of cleavage fracture, the brittle failure has been described using modified Beremin model. The influence of the stable crack growth on the cleavage failure probability in temperature transition region has been captured by coupling the ductile fracture model (GTN) with the modified Beremin model. Finally, examples have been presented for the practical application of the numerical results on the fracture assessment of the flawed high-strength pipelines. Y1 - 2012 ER - TY - CHAP A1 - Nonn, Aida A1 - Kalwa, Christoph T1 - The effect of microstructure, strain hardening and strain rate on the fracture behavior of high strength pipeline steels T2 - 2nd International Conference on Material Modelling (ICMM2), 31th August - 2nd September, 2011 at Mines Paris Tech, France Y1 - 2011 ER - TY - CHAP A1 - Nonn, Aida A1 - Kalwa, Christoph T1 - Application of probabilistic fracture mechanics for safety assessment of longitudinally welded linepipes T2 - 6th Pipeline Technology Conference (2013), Ostend, Belgium Y1 - 2013 ER - TY - CHAP A1 - Nonn, Aida A1 - Kalwa, Christoph T1 - Application of damage mechanics approach for crack propagation in pipeline T2 - 19th Biennial Joint Technical Meeting (JTM) on Pipeline Research, April 29 - May 3, 2013, Sydney, Australia Y1 - 2013 ER - TY - CHAP A1 - Nonn, Aida A1 - Erdelen-Peppler, Marion A1 - Wessel, Waldemar A1 - Mahn, Denise T1 - How reliable are the current testing procedures for the safety assurance against crack propagation in seamless gas pipelines T2 - Proceedings of the ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering (OMAE2014), Volume 4A: Structures, Safety and Reliability, June 8-13, 2014, San Francisco, USA N2 - The worldwide growing energy demand with the exploration of new gas fields has promoted the development of high toughness seamless pipeline steels which should sustain the increasing demands resulting from the complex loading situations. One of the most important prerequisites for safe installation and operation of long distance gas transmission pipelines is the detailed knowledge and characterization of their fracture performance for specific applications. However, recent industry experience has revealed concerns related to the limitations and reliability of current test methods for brittle-to-ductile transition evaluation. Regarding the transition temperature evaluation, the critical issues involve Drop-Weight Tear Testing (DWTT) and full-scale West-Jefferson (WJ) test applied to the smaller pipes with diameter less than 500mm. The DWTT leads frequently to invalid results in terms of abnormal fracture appearance and inverse fracture occurrence. It is still not clear if this behavior is only owed to a testing effect, which material characteristics cause it and how far it reflects the full-scale behavior. Similar observations were made for the West-Jefferson tests, which could not be assessed in the standard manner either. Again, the question was towards testing effects and the behavior of the pipeline transporting gaseous media remains unanswered. Therefore, this paper aims at identifying open questions on basis of a literature study and own experimental results and showing possible ways forward in demonstrating safety in design against propagating fracture. Y1 - 2014 U6 - https://doi.org/10.13140/2.1.3190.6567 ER - TY - CHAP A1 - Nonn, Aida A1 - Wessel, Waldemar A1 - Schmidt, Tanja T1 - Application of finite element analysis for assessment of fracture behavior of modern high toughness seamless pipeline steels T2 - 23rd International Society of Offshore and Polar Engineering 2013 (ISOPE 2013), Anchorage, USA N2 - Fracture behavior of seamless pipeline material X65Q acc. to API 5L has been studied both experimentally and numerically at different loading conditions (quasi-static vs. dynamic) and temperatures. The recent findings have shown difficulties in applying well established methods for determination of transition behavior or prediction of ductile crack arrest for the new generation of high-toughness steels. The irregular fracture performance (e.g. so-called "abnormal inverse fracture" appearance, significant scattering in ductile-to-brittle-transition-temperature region, etc.) suggests that the influence of pipe dimensions, loading parameters, crack initiation resistance as well as testing procedure on the fracture behavior has been neither understood nor properly described. This work aims to shed light on these questions regarding the applicability of conventional methods and to better illuminate most relevant parameters affecting fracture behavior of high toughness steels. To achieve this goal, experimental data basis for analysis of fracture behavior in transition and upper shelf regime has been established by conducting quasi-static fracture mechanics tests and dynamic tests on Battelle Drop Weight Tear (BDWT or DWT) specimens at different temperatures. The evaluation of obtained test results in upper shelf has been additionally complemented by numerical simulation of damage behavior. The results highlight the influence of stress conditions on fracture behavior with reference to pipe dimensions and loading conditions and, subsequently, may be used as a basis for revision of existing design methods. KW - Rissfortschritt KW - Nahtloses Rohr KW - Pipeline KW - Bruchmechanische Prüfung KW - Finite-Elemente-Methode Y1 - 2013 U6 - https://doi.org/10.13140/2.1.4239.2322 ER - TY - CHAP A1 - Nonn, Aida A1 - Paredes, Marcelo A1 - Keim, Vincent A1 - Wierzbicki, Tomasz T1 - Comparison of Fracture Models to Quantify the Effects of Material Plasticity on the Ductile Fracture Propagation in Pipelines T2 - Proceedings of the 2018 12th International Pipeline Conference, Volume 3: Operations, Monitoring, and Maintenance, Materials and Joining, September 24-28, 2018, Calgary, Alberta, Canada N2 - Various numerical approaches have been developed in the last years aimed to simulate the ductile fracture propagation in pipelines transporting CO2 or natural gas. However, a reliable quantification of the influence of material plasticity on the fracture resistance is still missing. Therefore, more accurate description of the material plasticity on the ductile fracture propagation is required based on a suitable numerical methodology. In this study, different plasticity and fracture models are compared regarding the ductile fracture propagation in X100 pipeline steel with the objective to quantify the influence of plasticity parameters on the fracture resistance. The plastic behavior of the investigated material is considered by the quadratic yield surface in conjunction with a non-associated quadratic plastic flow potential. The strain hardening can be appropriately described by the mixed Swift-Voce law. The simulations of ductile fracture are conducted by an uncoupled, modified Mohr-Coulomb (MMC) and the micromechanically based Gurson-Tvergaard-Needleman (GTN) models. In contract to the original GTN model, the MMC model is capable of describing ductile failure over wide range of stress states. Thus, ductile fracture resistance can be estimated for various load and fracture scenarios. Both models are used for the simulation of fracture propagation in DWTT and 3D pressurized pipe sections. The results from the present work can serve as a basis for establishing the correlation between plasticity parameters and ductile fracture propagation. Y1 - 2018 U6 - https://doi.org/10.1115/IPC2018-78366 ER - TY - CHAP A1 - Nonn, Aida A1 - Erdelen-Peppler, Marion A1 - Wessel, Waldemar A1 - Harksen, Silke A1 - Mahn, Denise T1 - How to assure fracture-propagation control for seamless gas pipelines? T2 - Proceedings of the 2014 10th International Pipeline Conference (IPC2014), Volume 3: Operations, Monitoring, and Maintenance, Materials and Joining, September 29-October 3, 2014, Calgary, Canada N2 - Fracture propagation control in gas transmission gas pipelines belongs to the major design requirements for safe operation at high internal pressures. However, the current tests such as Drop-Weight-Tear Test (DWTT) and full-scale West-Jefferson (WJ) test reach the limits of their applicability with respect to transition temperature evaluation for seamless quenched and tempered small diameter pipes reflecting nowadays alloying concepts related to mechanical properties. Hereby, different geometry and material effects are evident which might lead to misinterpretation and unreliability of testing results. This paper aims to discuss open issues addressed in the literature and in own experimental findings with respect to reliability and transferability of testing methods, fracture parameters and their representativeness of seamless quenched and tempered pipeline behavior. By applying damage mechanics approach, it is possible to quantify the prevailing stress state and thus to understand the mechanisms controlling specific fracture appearance (ductile or brittle). Furthermore, studies were performed with objective to quantify the effect of different parameters (geometry, material and loading) on the fracture performance of the pipeline. The results from these investigations will serve as a basis for a safe pipeline design against propagating fracture. Y1 - 2014 U6 - https://doi.org/10.1115/IPC2014-33169 ER - TY - CHAP A1 - Nonn, Aida A1 - Paredes, Marcelo A1 - Nordhagen, H. O. A1 - Munkejord, S. T. A1 - Wierzbicki, Tomasz T1 - Challenges in fluid-structure modeling of crack propagation and arrest in modern steel pipelines T2 - 14th International Congress on Fracture (ICF14), 18-23 June 2017, Rhodes, Greece Y1 - 2017 SP - 1351 EP - 1352 ER - TY - CHAP A1 - Karbasian, H. A1 - Groß-Weege, J. A1 - Nonn, Aida A1 - Zimmermann, S. A1 - Kalwa, Christoph T1 - Assessment of collapse resistance of UOE pipes – comparison of full-scale and ring collapse tests T2 - Proceedings of the 10th International Pipeline Conference 2014 (IPC 2014), September 29 - October 3, 2014, Calgary, Alberta, Canada Y1 - 2014 ER - TY - CHAP A1 - Lang, Christian A1 - Steinborn, Florian A1 - Steffens, Oliver A1 - Lang, Elmar Wolfgang ED - Valenzuela, O. ED - Rojas, F. ED - Herrera, L.J. ED - Pomares, H. ED - Rojas, I. T1 - Applying a 1D-CNN Network to Electricity Load Forecasting T2 - Theory and Applications of Time Series Analysis N2 - This paper presents a convolutional neural network (CNN) which can be used for forecasting electricity load profiles 36 hours into the future. In contrast to well established CNN architectures, the input data is one-dimensional. A parameter scanning of network parameters is conducted in order to gain information about the influence of the kernel size, number of filters and number of nodes. Furthermore, different dropout methods are applied to the CNN and are evaluated. The results show that a good forecast quality can already be achieved with basic CNN architectures, the dropout improves the forecast. The method works not only for smooth sum loads of many hundred consumers, but also for the load of single apartment buildings. KW - Energy load forecasting KW - STLF KW - Neural networks KW - CNN KW - Convolutional networks Y1 - 2020 U6 - https://doi.org/10.1007/978-3-030-56219-9_14 SP - 205 EP - 218 PB - Springer ER - TY - CHAP A1 - Schneider, Ingo A1 - Nonn, Aida A1 - Völling, Alexander A1 - Mondry, A. A1 - Kalwa, Christoph T1 - A damage mechanics based evaluation of dynamic fracture resistance in gas pipelines T2 - Procedia Materials Science, Volume 3 N2 - Investigation of running ductile fracture in gas transmission pipelines and the derivation of reliable crack arrest prediction methods belong to major topics in pipeline research. The yet available crack arrest criterion, known as the Battelle Two-Curve Method (BTCM), leads to reliable predictions up to grade X70 line pipe steels for which it has been validated. This includes specific limits in terms of mechanical properties, pressure and geometry. The application of this criterion to modern pipeline steels, i.e. especially grades X80 and beyond in combination with larger diameters and high pressure, has led to mispredictions of the BTCM. Hence, in order to ensure safe design of pipelines, new methods are required based on in depth knowledge and appropriate characterization of material resistance. This paper presents a procedure for the assessment of dynamic ductile fracture resistance based on combined experimental and numerical investigations. The procedure involves quasi-static and dynamic drop- weight tear testing (DWTT) on modified specimens with pre-fatigued crack for grades X65, X80 and X100 materials, and the application of cohesive zone (CZ) and Gurson-Tveergard-Needleman (GTN) models to describe ductile material damage. The damage model parameters are calibrated on basis of DWTT results and subsequently used to simulate dynamic crack propagation in a pipeline. The influence of material properties (strain hardening, toughness), pipe geometry, usage factor and decompression behaviour on ductile fracture propagation behaviour is studied and evaluated. The results will contribute to an enhanced understanding of major parameters controlling ductile fracture propagation and will help to establish a reliable procedure for safe design of new high-capacity pipelines with regard to crack arrest. KW - Pipeline KW - Dynamic ductile fracture KW - Crack arrest KW - Cohesive zone model KW - DWT testing Y1 - 2014 U6 - https://doi.org/10.1016/j.mspro.2014.06.315 VL - 3 SP - 1956 EP - 1964 ER - TY - CHAP A1 - Kofiani, Kirki A1 - Nonn, Aida A1 - Wierzbicki, Tomasz A1 - Kalwa, Christoph A1 - Walters, Carey T1 - Experiments and fracture modeling of high-strength pipelines for high and low stress triaxiality T2 - 22nd International Society of Offshore and Polar Engineering 2012 (ISOPE 2012), Rhodes, Greece, June 2012 N2 - This paper provides results from a comprehensive study on mechanical characterization of high-strength pipeline steel, grade X100 using experimental and numerical methods. The material was characterized for anisotropic plasticity, fracture initiation for various states of stress, (pre-cracked) fracture toughness and uncracked ductility. The experimental program included tests on flat butterfly-shaped, central hole, notched and circular disk specimens for low stress triaxiality levels; as well as tests on round notched bar specimens and SENT fracture mechanics tests, for high values of stress triaxiality. This program covered a wide range of stress conditions and demonstrated its effect on the material resistance. Parallel to the experimental study, detailed numerical investigations were carried out to simulate all different experimental tests. Using an inverse method, a 3-parameter calibration was performed on the Modified Mohr-Coulomb (MMC) fracture model. Subsequently, the predictive capabilities of the MMC were evaluated by the comparison to the fracture toughness tests results, used extensively in the pipeline industry. The capabilities of the MIT fracture model have been demonstrated on an example of high strength offshore steel, X100. The outcome of this study was not only to provide, the overall characterization of the fracture behavior of this material as an example, but also to present the methodology on how to use the MMC model as a practical tool in pipeline design. Y1 - 2012 ER - TY - RPRT ED - Neuleitner, Nikolaus ED - Steffens, Oliver T1 - Energienutzungsplan für die Gemeinde Sinzing BT - Phase I. Bestandsaufnahme. Ergebnisbericht 1 (12/2011) Y1 - 2011 ER - TY - CHAP A1 - Zenger, Gerhard A1 - Kenner, Susanne A1 - Volbert, Klaus A1 - Waas, Thomas A1 - Kucera, Markus T1 - Acquiring energy data from a medium-voltage grid for future smart grid solutions: A practical smart grid application example realized by use of cellular communication networks of the 2nd and 3rd generation T2 - Proceedings of the 11th Workshop on Intelligent Solutions in Embedded Systems (WISES), 10-11 Sept. 2013, Pilsen, Czech Republic N2 - In this paper we present a practical example of the use of Cellular Communication standards like GPRS and UMTS in a Smart Grid Application. For a more detailed view we demonstrate a possible implementation of Cellular Communication Technologies in a data acquisition application for the collection of energy indicators in a medium-voltage grid. Furthermore, we show a technical overview of relevant and common mobile communication standards available in Germany. The included theoretical examples, Smart Grid scenarios, presented data and results are based on a research project for intelligent power regulation in medium-voltage grids performed in Regensburg (Germany). It is a joint project' of the University of Applied Sciences Regensburg together with a local energy provider and a manufacturer for distribution network systems. KW - Mobile communication KW - Medium voltage KW - Standards KW - Smart grids KW - Feeds KW - Ground penetrating radar Y1 - 2013 UR - https://ieeexplore.ieee.org/document/6664954 SN - 978-3-00-042899-9 SP - 1 EP - 8 PB - IEEE ER - TY - CHAP A1 - Kenner, Susanne A1 - Thaler, Raphael A1 - Kucera, Markus A1 - Volbert, Klaus A1 - Waas, Thomas T1 - Smart Grid architecture for monitoring and analyzing, including modbus and REST performance comparison T2 - International Workshop on Intelligent Solutions in Embedded Systems (WISES), 12th, 29.-30. Oct. 2015, Ancona, Italy N2 - Smart Grid, Smart Metering, Electromobility and the regulation of the power network are keywords of the transition in energy policies. In the future, the power grid will be smart. Due to this the OTH Regensburg does research in this area based on different projects. This paper presents a data collection, analyzing and monitoring software for a reference Smart Grid. We discuss two possible architectures for collecting data from energy analyzers. The performance is analyzed with respect to real-time monitoring, analyzing load peaks and automated regulation of the power grid. KW - Software KW - Computer architecture KW - Smart grids KW - Protocols KW - Databases KW - Servers KW - TCPIP Y1 - 2015 UR - https://ieeexplore.ieee.org/document/7356988 SN - 978-8-8875-4808-2 SP - 96 ER - TY - CHAP A1 - Brunner, Stefan A1 - Röder, Jürgen A1 - Kucera, Markus A1 - Waas, Thomas T1 - Automotive E/E-architecture enhancements by usage of ethernet TSN T2 - 13th Workshop on Intelligent Solutions in Embedded Systems (WISES), 12-13 June 2017, Hamburg, Germany N2 - A huge upheaval emerges from the transition to autonomous vehicles in the domain of road vehicles, ongoing with a change in the vehicle architecture. Many sensors and Electronic Control Units are added to the current vehicle architecture and further safety requirements like reliability become even more necessary. In this paper we present a potential evolution of the Electrical/Electronic-Architecture, including a Zone Architecture, to enable future functionality. We reveal the impact on the communication network concerning these architectures and present a potential communication technology to facilitate such architectures. KW - Logic gates KW - Computer architecture KW - Standards KW - Quality of service KW - Complexit KW - Kraftfahrzeug KW - Softwarearchitektur KW - TSN-Netz Y1 - 2017 U6 - https://doi.org/10.1109/WISES.2017.7986925 SP - 9 EP - 13 PB - IEEE ER - TY - CHAP A1 - Buttner, Johannes A1 - Alonso-Villa, Cristina A1 - Bohigas Boladeras, Pere A1 - Kucera, Markus A1 - Waas, Thomas T1 - The Need for New Software Architectures for Next-generation Vehicle T2 - Proceedings of the 5th International E-Conference on Advances in Engineering, Technology and Management (ICETM 2021) N2 - Assuming that future connected cars with automated driving functions will require even more computing power and communication bandwidth, the current network infrastructure as well as the existing individualized control units are not a profitable option for such vehicles. In addition, changing user expectations demand flexible architectural patterns and upgradeability of software components without the need to visit the workshop. However, the current statically developed and configured ECU architecture does not offer any practicable possibilities for this. For these reasons, the research for a new dynamic and flexible architecture is necessary. This new type of system architecture is expected to meet future requirements in terms of space, cost, performance, energy efficiency and number of required computing units in the vehicle, which will arise as a result of the implementation/inclusion of new automated driving functionalities, and due to the changes in user expectations. Solutions to this issue can be found in the field of enterprise IT (cluster computing), in which technologies such as Ethernet, container-based virtualization and flexible software architectures have proven themselves to be very efficient for years. Relevant infrastructures, for example from cloud computing providers, have commonly been used in high-performance or high-availability applications. Thus, in the research project A 3F has been investigated which of these concepts and methods can be applied to modern vehicle system architectures. One of the main goals is to assess the synergy potential of the two sectors, information technology and automotive industry, which to date have very different orientations. However, this synergy is expected to grow strongly in the course of the developments mentioned above. In the following pages, the necessary changes related to hardware and software will be discussed briefly und will be compared to concepts and possible solutions from the IT world. Y1 - 2021 UR - https://www.seekdl.org/conferences/paper/details/10605.html SN - 978-1-63248-192-4 SP - 58 EP - 61 ER - TY - CHAP A1 - Büttner, Johannes A1 - Bohigas Boladeras, Pere A1 - Gottschalk, Philipp A1 - Kucera, Markus A1 - Waas, Thomas T1 - Performance Isolation of Co-located Workload in a Container-based Architecture for Automobile T2 - 9th International Conference on Ambient Computing, Applications, Services and Technologies 2019, 22-26.09.2019, Porto, Portugal N2 - As the development in the automotive sector is facing upcoming challenges, the demand for in-vehicle computing power capacity increases and the need for flexible hardware and software structures arises, allowing dynamic managament of resources. In this new scenario, software components are to be added, removed, updated and migrated between computing units. To isolate the software components from each other and allow its orchestration, a container-based virtualization approach is being tested throughout this research. The analysis focuses on the question if this virtualization technology could be an option to ensure an interference-free operation. Four different sample applications from the automotive environment are tested for their susceptibility to resource contention. The research on the one hand shows that CPU and memory used by an application can be largely isolated with this technology, but on the other hand, it becomes apparent that support for I/O-heavy usage is currently not implemented sufficiently for container engines. KW - container-based virtualization KW - resource management KW - resource isolation KW - stress testing Y1 - 2019 UR - https://ns2.thinkmind.org/articles/ambient_2019_2_20_40020.pdf SN - 978-1-61208-739-9 SP - 31 EP - 37 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 - Chen, Rui A1 - Zhang, Zhuo A1 - Song, Ruizhou A1 - Fang, Cheng A1 - Sindersberger, Dirk A1 - Monkman, Gareth J. A1 - Guo, Jianglong T1 - Time-dependent electroadhesive force degradation JF - Smart Materials and Structures N2 - This paper concerns a comprehensive investigation of time-dependent electroadhesion (EA) force degradation. EA shear force tests on different object materials (a PET, glass, ABS, and wood plate) have shown that force degradation was dominated by residual polarization charges trapped in the EA pad dielectric rather than in the substrate dielectric from which the object to be prehended is made. In order to explain this dynamic physical phenomenon, a model of dielectric polarization and depolarization has been proposed. According to the derived relationship between EA force and discharge time, three different methods intended to mitigate this problem has been compared: (1) the natural discharge method, (2) the high voltage resistor discharge method, and (3) the discharge prior to field polarity reversal method. These methods are useful for generating repeatable and stable EA forces, which are required for the characterization of EA pads and their subsequent employment in material handling, mobile robot crawling and climbing tasks. Y1 - 2020 U6 - https://doi.org/10.1088/1361-665X/ab79b5 VL - 29 IS - 5 PB - IOP Publishing 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 - 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 - 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 - 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 - Kurzweil, Peter A1 - Scheuerpflug, Wolfgang T1 - State-of-charge monitoring and battery diagnosis of different lithium ion chemistries using impedance spectroscopy JF - Batteries N2 - For lithium iron phosphate batteries (LFP) in aerospace applications, impedance spectroscopy is applicable in the flat region of the voltage-charge curve. The frequency-dependent pseudocapacitance at 0.15 Hz is presented as useful state-of-charge (SOC) and state-of-health (SOH) indicator. For the same battery type, the prediction error of pseudocapacitance is better than 1% for a quadratic calibration curve, and less than 36% for a linear model. An approximately linear correlation between pseudocapacitance and Ah battery capacity is observed as long as overcharge and deep discharge are avoided. We verify the impedance method in comparison to the classical constant-current discharge measurements. In the case of five examined lithium-ion chemistries, the linear trend of impedance and SOC is lost if the slope of the discharge voltage curve versus SOC changes. With nickel manganese cobalt (NMC), high impedance modulus correlates with high SOC above 70%. KW - battery life testing KW - capacitance KW - lithium-ion battery KW - state-of-charge determination KW - state-of-health KW - pseudocharge KW - impedance spectroscopy KW - aging Y1 - 2021 U6 - https://doi.org/10.3390/batteries7010017 VL - 7 IS - 1 ER - TY - JOUR A1 - Schmidt, Henrik A1 - Straub, Benedikt B. A1 - Sindersberger, Dirk A1 - Bröckel, Ulrich A1 - Monkman, Gareth J. A1 - Auernhammer, Günter T1 - Collision and separation of nickel particles embedded in a Poly dimethylsiloxan matrix under a rotating magnetic field: A strong magneto active function JF - Colloid and Polymer Science N2 - In order to function as soft actuators, depending on their field of use, magnetorheological elastomers (MREs) must fulfill certain criteria. To name just a few, these can include rapid response to external magnetic fields, mechanical durability, mechanical strength, and/or large deformation. Of particular interest are MREs which produce macroscopic deformation for small external magnetic field variations. This work demonstrates how this can be achieved by just a small change in magnetic field orientation. To achieve this, (super)paramagnetic nickel particles of size ≈ 160 μm were embedded in a non-magnetic polydimethylsiloxan (PDMS) (661–1301 Pa) and their displacement in a stepwise rotated magnetic field (170 mT) recorded using a video microscope. Changes in particle aggregation resulting from very small variations in magnetic field orientation led to the observation of a new strongly magneto-active effect. This configuration is characterized by an interparticle distance in relation to the angle difference between magnetic field and particle axis. This causes a strong matrix deformation which in turn demonstrates hysteresis on relaxation. It is shown that the occurrence strongly depends on the particle size, particle distance, and stiffness of the matrix. Choosing the correct parameter combination, the state can be suppressed and the particle-matrix system demonstrates no displacement or hysteresis. In addition, evidences of non-negligible higher order magnetization effects are experimentally ascertained which is qualitatively in agreement with similar, already theoretically described, particle systems. Even at larger particle geometries, the new strongly magneto-active configuration is preserved and could create macroscopic deformation changes. Y1 - 2021 U6 - https://doi.org/10.1007/s00396-020-04784-4 VL - 299 SP - 955 EP - 967 PB - Springer ER - TY - JOUR A1 - Schroll-Decker, Irmgard T1 - Rezension zu: Ethik des Wissens. Freiheit und Verantwortung der Wissenschaft in Zeiten des Klimawandels. oekom Verlag (München) 2019. ISBN 978-3-96238-163-9 JF - socialnet Rezensionen Y1 - 2020 UR - https://www.socialnet.de/rezensionen/26341.php SN - 2190-9245 ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Yuskevich, Pavel T1 - Effective medium theory for the elastic properties of composite materials with various percolation thresholds JF - Materials N2 - It is discussed that the classical effective medium theory for the elastic properties of random heterogeneous materials is not congruous with the effective medium theory for the electrical conductivity. In particular, when describing the elastic and electro-conductive properties of a strongly inhomogeneous two-phase composite material, the steep rise of effective parameters occurs at different concentrations. To achieve the logical concordance between the cross-property relations, a modification of the effective medium theory of the elastic properties is introduced. It is shown that the qualitative conclusions of the theory do not change, while a possibility of describing a broader class of composite materials with various percolation thresholds arises. It is determined under what conditions there is an elasticity theory analogue of the Dykhne formula for the effective conductivity. The theoretical results are supported by known experiments and show improvement over the existing approach. The introduction of the theory with the variable percolation threshold paves the way for describing the magnetorheological properties of magnetoactive elastomers. A similar approach has been recently used for the description of magneto-dielectric and magnetic properties. KW - elastic properties KW - effective medium approximation KW - self-consistent KW - random heterogeneous medium KW - two-phase composite material KW - percolation threshold Y1 - 2020 U6 - https://doi.org/10.3390/ma13051243 VL - 13 IS - 5 SP - 1 EP - 19 PB - MPDI CY - Basel ER - TY - CHAP A1 - Bünte, Tilman A1 - Rill, Georg A1 - Ruggaber, Julian A1 - Tobolář, Jakub ED - Orlova, Anna ED - Cole, David T1 - Modelling and Validation of the TMeasy Tyre Model for Extreme Parking Manoeuvres T2 - Advances in Dynamics of Vehicles on Roads and Tracks II, Proceedings of the 27th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2021): August 17-19, 2021, Saint Petersburg, Russia N2 - The TMeasy is a tyre model suitable for vehicle handling analyses and enables easy parametrisation. Recently, a convenient interface to Modelica was implemented by DLR to support the TMeasy also for vehicle modelling in multi-physical domains. This paper focuses especially on the particular problem of reliable reproduction of the tyre’s bore torque which occurs during parking manoeuvres. It outlines the theory behind it, discusses the Modelica interface implementation, and presents the results of parameter identification which were achieved based on real experiments with DLR’s research platform ROboMObil. Y1 - 2022 SN - 978-3-031-07305-2 SN - 978-3-031-07304-5 U6 - https://doi.org/10.1007/978-3-031-07305-2_94 SP - 1015 EP - 1025 PB - Springer CY - Cham ER - TY - JOUR A1 - Rill, Georg A1 - Bauer, Florian A1 - Topcagic, Edin T1 - Performance of leaf spring suspended axles in model approaches of different complexities JF - Vehicle System Dynamics N2 - Axles with leaf spring suspension systems are still a popular choice in many commercial vehicles. However, leaf springs are not in perfect conformity to standard multibody vehicle models because they combine guidance and suspension in one single element. Combining standard multibody vehicle models with sophisticated finite element leaf spring models results in rather complex and computing time-consuming solutions. Purely kinematic models, defined by lookup tables or the design kinematics approach, cover only some but not all features of the leaf spring suspension. As shown here, the five-link model, which incorporates a quasi-static solution of the leaf spring compliance, provides a very practical model. It is comparatively lean and provides results of sufficient accuracy in the whole application range. KW - beam-model KW - commercial vehicles KW - design kinematics KW - five-Link model KW - Leaf spring suspension KW - vehicle dynamics Y1 - 2021 U6 - https://doi.org/10.1080/00423114.2021.1928249 VL - 60 IS - 8 SP - 2871 EP - 2889 PB - Taylor&Francis ER - TY - JOUR A1 - Keiner, Dominik A1 - Ram, Manish A1 - Barbosa, Larissa de Souza Noel Simas A1 - Bogdanov, Dmitrii A1 - Breyer, Christian T1 - Cost optimal self-consumption of PV prosumers with stationary batteries, heat pumps, thermal energy storage and electric vehicles across the world up to 2050 JF - Solar Energy N2 - Globally, PV prosumers account for a significant share of the total installed solar PV capacity, which is a growing trend with ever-increasing retail electricity prices. Further propelled by performance improvements of solar PV and innovations that allow for greater consumer choice, with additional benefits such as cost reductions and availability of incentives. PV prosumers may be one of the most important enablers of the energy transition. PV prosumers are set to gain the most by maximising self-consumption, while avoiding large amounts of excess electricity being fed into the grid. Additionally, electricity and heat storage technologies, heat pumps and battery electric vehicles are complementary to achieve the highest possible self-consumption shares for residential PV prosumer systems, which can reach grid-parity within this decade in most regions of the world. This research finds the cost optimal mix of the various complementary technologies such as batteries, electric vehicles, heat pumps and thermal heat storage for PV prosumers across the world by exploring 4 different scenarios. Furthermore, the research presents the threshold for economical maximum battery capacity per installed PV capacity, along with self-consumption ratios, demand cover ratios and heat cover ratios for 145 different regions across the world. This is a first of its kind study to conduct a global analysis of PV prosumers with a range of options to meet their complete energy demand from a future perspective, up to 2050. Maximising self-consumption from solar PV generation to meet all energy needs will be the most economical option in the future, for households across most regions of the world. KW - Battery KW - Electric vehicle KW - EMISSIONS KW - Heat pump KW - LIFE-CYCLE COST KW - Optimization KW - Photovoltaics KW - POWER-TO-HEAT KW - Prosumer KW - RESIDENTIAL HEAT KW - SYSTEMS KW - TECHNOLOGIES KW - Thermal energy storage KW - Vehicle-to-home Y1 - 2019 U6 - https://doi.org/10.1016/j.solener.2019.04.081 VL - 185 SP - 406 EP - 423 PB - Elsevier ER - TY - JOUR A1 - Kahl, Matthias A1 - Krause, Veronika A1 - Hackenberg, Rudolf A1 - Ul Haq, Anwar A1 - Horn, Anton A1 - Jacobsen, Hans-Arno A1 - Kriechbaumer, Thomas A1 - Petzenhauser, Michael A1 - Shamonin (Chamonine), Mikhail A1 - Udalzow, Anton T1 - Measurement system and dataset for in-depth analysis of appliance energy consumption in industrial environment JF - tm - Technisches Messen N2 - To support a rational and efficient use of electrical energy in residential and industrial environments, Non-Intrusive Load Monitoring (NILM) provides several techniques to identify state and power consumption profiles of connected appliances. Design requirements for such systems include a low hardware and installations costs for residential, reliability and high-availability for industrial purposes, while keeping invasive interventions into the electrical infrastructure to a minimum. This work introduces a reference hardware setup that allows an in depth analysis of electrical energy consumption in industrial environments. To identify appliances and their consumption profile, appropriate identification algorithms are developed by the NILM community. To enable an evaluation of these algorithms on industrial appliances, we introduce the Laboratory-measured IndustriaL Appliance Characteristics (LILAC) dataset: 1302 measurements from one, two, and three concurrently running appliances of 15 appliance types, measured with the introduced testbed. To allow in-depth appliance consumption analysis, measurements were carried out with a sampling rate of 50 kHz and 16-bit amplitude resolution for voltage and current signals. We show in experiments that signal signatures, contained in the measurement data, allows one to distinguish the single measured electrical appliances with a baseline machine learning approach of nearly 100% accuracy. KW - appliance monitoring KW - DAQ KW - NILM Y1 - 2019 U6 - https://doi.org/10.1515/teme-2018-0038 VL - 86 IS - 1 SP - 1 EP - 13 PB - De Gruyter ER - TY - JOUR A1 - Mikhaeil, Makram A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - On the application of adsorber plate heat exchangers in thermally driven chillers BT - An experimental and analytical study JF - Applied Thermal Engineering N2 - The effect of both heat and mass transfer characteristic lengths (HTCL, MTCL) of two different adsorber plate heat exchangers (APHE), for application in an adsorption chiller, on the adsorption and desorption kinetics is investigated. Three representative test frames (TF1-TF3) are prepared to examine small-scale adsorbent samples of the microporous silica gel (Siogel of Oker-Chemie, Germany) applying the volumetric large-temperature-jump methodology at different operating conditions. Based on the obtained kinetic data, an analytical model has been developed to predict the specific cooling power (SCP) and the coefficient of performance (COP) of a single-bed adsorption chiller comprising the studied APHEs. It turned out that, within the tested range of HTCL and MTCL, it can be concluded that, the adsorption kinetics are mainly influenced by the MTCL, while the desorption kinetics are dominated by the HTCL of the adsorbent domain. Applying Siogel as loose pellets inside a newly introduced APHE results in of 423.3 and 182.7 W⋅kg−1, at the evaporator temperatures of 15 °C and 5 °C, respectively. Herein, the condenser and adsorber-end temperatures amount to 30 °C and the desorption-end temperature to 90 °C. The corresponding s amount to 0.50 and 0.40, respectively, which represent quite promising results for further design optimizations. Y1 - 2023 U6 - https://doi.org/10.1016/j.applthermaleng.2022.119713 VL - 220 PB - Elsevier ER - TY - JOUR A1 - Vérez, David A1 - Borri, Emiliano A1 - Crespo, Alicia A1 - Zsembinszki, Gabriel A1 - Dawoud, Belal A1 - Cabeza, Luisa F. T1 - Experimental Study of a Small-Size Vacuum Insulated Water Tank for Building Applications JF - Sustainability N2 - Insulation of thermal energy storage tanks is fundamental to reduce heat losses and to achieve high energy storage efficiency. Although water tanks were extensively studied in the literature, the enhancement of the insulation quality is often overlooked. The use of vacuum insulation has the potential to significantly reduce heat losses without affecting the dimension of the storage system. This paper shows for the first time the results of the heat losses tests done for a 0.535 m3 water tank for residential building applications built with a double wall vacuum insulation. The different tests show that the rate of heat losses strictly depends on the temperature distribution inside the tank at the beginning of the experiment. Compared to a conventional water tank insulated with conventional materials, the U-value of the lateral surface was reduced by almost three times (from 1.05 W/K·m2 to 0.38 W/K·m2) using vacuum insulation. However, the bottom part, which is usually used to place the support parts and the piping, is the critical design part of those tanks acting as a thermal bridge with the ambient and enhancing heat losses. Y1 - 2021 U6 - https://doi.org/10.3390/su13105329 VL - 13 IS - 10 SP - 1 EP - 11 PB - MDPI CY - Basel 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 - De, Sangita A1 - Niklas, Michael A1 - Mottok, Jürgen A1 - Brada, Přemek T1 - A Semantic Analysis of Interface Description Models of Heterogeneous Vehicle Application Frameworks: An Approach Towards Synergy Exploration T2 - MODELSWARD 2019: Proceedings of the 7th International Conference on Model-Driven Engineering and Software Development, 20.02.2019 - 22.02.2019, Prague, Czech Republic N2 - As the world is getting more connected, the demands of services in automotive industry are increasing with the requirements such as IoT (Internet of Things) in cars, automated driving, etc. Eventually, the automotive industry has evolved to a complex network of servi ces, where each organization depends on the other organizations, to satisfy its service requirements in different phases of the vehicle life cycle. Because of these heterogeneous and complex development environments, most of the vehicle component interface models need to be specified in various manifest ations to satisfy the semantic and syntactic requirements, specific to different application development environments or frameworks. This paperdescribes an approach to semantic analysis of components interfaces description models of heterogeneous frameworks, that are used for vehicle applications. The proposed approach intends to ensure that interface description models of different service-based vehicle frameworks can be compared, correlated and re-used based on semantic synergies, across different vehicle platforms, development environments and organizations. The approach to semantic synergy exploration could further provide the knowledge base for the increase in interoperability, overall efficiency and development of an automotive domain specific general software solutions, by facilitating coexistence of components of heterogeneous frameworks in the same high-performance ECU for future vehicle software. KW - Application: Framework KW - IDL KW - Semantic: Mapping Y1 - 2019 SN - 978-989-758-358-2 SP - 394 EP - 401 PB - SCITEPRESS ER - TY - CHAP A1 - Reindl, Andrea A1 - Meier, Hans A1 - Niemetz, Michael A1 - Park, Sangyoung T1 - Decentralized Battery Management System with Customized Hardware Components T2 - IEEE 19th Student Conference on Research and Development (SCOReD), Sustainable Engineering and Technology towards Industry Revolution: 23-25 Nov. 2021, Kota Kinabalu, Malaysia N2 - With an increasing number of sold electric vehicles (EVs), a large number of used batteries will be at disposal. How to deal with these resources is one of the major challenges in reducing the environmental impact of batteries throughout their entire life cycle. Heterogeneous cell parameters due to the different usage histories are a challenge for second-life use. The effort and cost of remanufacturing required to test and assemble a new battery pack is a further concern. Systems that combine battery packs/modules without full reassembly offer advantages such as cost and reusability. A decentralized battery management system (DBMS) provides a suitable architecture for such systems involving different types of batteries. In this paper, an architecture for a decentralized, battery state-dependent control is shown. The proposed DBMS supports various types of batteries, is scalable and flexibly adaptable for a wide range of applications. Despite the significant advantages, there are increased requirements to meet for the hardware implementation and the applied control strategies. Therefore, the necessary hardware components and their requirements are described and the hardware implementations are provided. KW - battery fitness KW - Battery management system KW - Battery management systems KW - bidirectional power flow KW - Computer architecture KW - Costs KW - DC-DC power converters KW - decentralized control KW - Electric vehicles KW - Hardware KW - load sharing KW - Microprocessors KW - Renewable energy sources KW - second life battery Y1 - 2021 U6 - https://doi.org/10.1109/SCOReD53546.2021.9652737 SP - 350 EP - 355 PB - IEEE ER - TY - CHAP A1 - Hopkins, Andrew A1 - Hopfensperger, Bernhard A1 - Mellor, Phil T1 - DC-link Capacitor Reduction in Low Voltage and High Power Integrated Modular Motor Drives T2 - 2019 IEEE Energy Conversion Congress and Exposition (ECCE), 29 Sept.-3 Oct. 2019, Baltimore, MD, USA N2 - The development of 48V high power (>15 kW) automotive propulsion drives demands close integration of the power electronics and the electrical machine. Due to the large operating currents distributed multi-phase topologies are needed and physically separating the power converter from the e-machine would involve heavy cabling and costly connections. The volume and cost of the filter capacitor represents a major challenge in closely integrated high power integrated modular motor drives and techniques are needed to minimize this. The DC-link capacitor requires a large ripple current handling capability and cost, size and reliability limitations result in suitable candidate technologies being those with low volumetric energy densities. Use of interleaved multi three-phase machines are attractive due to the associated capacitor ripple current reduction. Discontinuous modulation schemes may also be employed as a technique for reducing the current ripple. In this paper techniques for capacitor ripple reduction are assessed through simulation and compared. KW - Capacitors KW - carrier phase shift KW - DC-link capacitor KW - dual 3-phase inverter KW - integrated modular motor drive KW - Interleaving KW - Inverters KW - Low voltage KW - Motor drives KW - Pulse width modulation KW - ripple current reduction KW - winding displacement KW - Windings Y1 - 2019 U6 - https://doi.org/10.1109/ECCE.2019.8913213 SP - 3208 EP - 3214 ER - TY - JOUR A1 - Sýkora, Miroslav A1 - Holicky, Milan A1 - Jung, Karel A1 - Diamantidis, Dimitris T1 - Human safety criteria for risk-based structural design JF - International Journal of Safety and Security Engineering N2 - Risk and reliability criteria are well established in many industrial sectors such as the offshore, chemi- cal or nuclear industries. Comparative risk thresholds have been specified to allow a responsible organization or regulator to identify activities, which impose an acceptable level of risk concerning the participating individuals, or society as a whole. The scope of this contribution is to present target reliability criteria based on acceptable human safety levels. Application of theoretical principles is illustrated by examples of railway engineering structures. Initially it is shown how civil engineering structures for which human safety criteria play a role are classified according to Eurocodes. Examples include bridges, tunnels or station buildings. The general concepts for risk acceptance are then briefly reviewed, particularly in their relation to the target reliability criteria. The distinction between the two types of criteria is made: group risk and the acceptance criterion based on the Life Quality Index LQI approach introduced by ISO 2394:2015. The differences between the criteria for new and existing structures are discussed. The application is illustrated by an example of a bridge crossing an important railway line. It appears that while benefits and costs of a private stakeholder or public authority are reflected by economic optimisation, the society should define the limits for human safety to achieve uniform risks for various daily-life activities and across different industrial sectors. Keywords: group risk, human safety, individual risk, Life Quality Index, railway, risk acceptance, structure, target reliability KW - individual risk KW - group risk KW - human safety KW - Life Quality Index KW - railway KW - risk acceptance KW - structure KW - target reliability Y1 - 2018 U6 - https://doi.org/10.2495/SAFE-V8-N2-287-298 VL - 8 IS - 2 SP - 287 EP - 298 PB - WIT Press ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav A1 - Bertacca, Elena T1 - Obsolescence Rate: Framework, Analysis and Influence on Risk Acceptance Criteria T2 - 6th International Symposium on Life-Cycle Civil Engineering (IALCCE), Ghent, Belgium N2 - Buildings are major long lasting assets of the society and business enterprises and form a significant part of infrastructure management. They require continual maintenance and in many cases they can become inap-propriate for their original purpose due to obsolescence and are demolished. The present contribution ex-plores the obsolescence of buildings and in particular the definitions of obsolescence, the related influenc-ing factors and the associated uncertainties. Thereby definitions of the obsolescence rate based on the physi-cal and useful (service) life are clarified. The experienced useful life of buildings in Finland, Germany and North America is statistically analysed, utilizing available databases, and comparisons with the design (minimum) working life specified in standards are made. The probability of not exceeding the required min-imum service life is evaluated and discussed. Whereas many factors affecting the obsolescence rate are be-yond the control of civil engineers, particular attention needs to be paid to cases where the service life of the structure is determined by physical aspects related to deterioration. These cases are identified and recom-mendations to improve structural design are offered. The service life and the related renewal rate is influ-encing the risk acceptance criteria as given in ISO 2394. Such criteria are derived on the basis of economic optimization and the LQI marginal safety costs principle. A statistical model for the renewal rate is obtained and its influence on the target reliability is investigated for a representative failure limit state. The influence of the obsolescence rate is quantified and critically disputed. Y1 - 2018 UR - https://www.researchgate.net/publication/328578867_Obsolescence_Rate_Framework_Analysis_and_Influence_on_Risk_Acceptance_Criteria ER - TY - CHAP A1 - Briem, Ulrich ED - Scholten, Jan T1 - Neue Methode zur Bestimmung der Biegesteifigkeit von Drahtseilen T2 - Der Kran - Leistungssteigerung, Leichtbau und Automatisierung : 27. Internationale Kranfachtagung 2019 : Begleitband zur Kranfachtagung am 07. März 2019 in Bochum Y1 - 2019 SN - 3-89194-226-5 SP - 103 EP - 112 PB - Selbstverlag der Ruhr-Universität Bochum CY - Bochum ER - TY - CHAP A1 - Carrillo Li, Enrique Roberto A1 - Schorr, Philipp A1 - Kaufhold, Tobias A1 - Rodríguez Hernández, Jorge Antonio A1 - Zentner, Lena A1 - Zimmermann, Klaus A1 - Böhm, Valter ED - Awrejcewicz, Jan ED - Kaźmierczak, Markek ED - Olejnik, Paweł T1 - Kinematic analysis of the rolling locomotion of mobile robots based on tensegrity structures with spatially curved compressed components T2 - Applicable Solutions in Non-Linear Dynamical Systems; 15th International Conference "Dynamical Systems - Theory and Applications" (DSTA 2019, 2-5 December, 2019, Lodz, Poland N2 - In this work, a tensegrity structure with spatially curved members is applied as rolling locomotion system. The actuation of the structure allows a variation of the originally cylindrical shape to a conical shape. Moreover, the structure is equipped with internal movable masses to control the position of the center of mass of the structure. To control the locomotion system a reliable actuation strategy is required. Therefore, the kinematics of the system considering the nonholonomic constraints are derived in this paper. Based on the resulting insight in the locomotion behavior a feasible actuation strategy is designed to control the trajectory of the system. To verify this approach kinematic analyses are evaluated numerically. The simulation data confirm the path following due to an appropriate shape change of the tensegrity structure. Thus, this system enables a two-dimensional rolling locomotion. The use of mechanically compliant tensegrity structures in mobile robots is an attractive research topic, due to the possibility to adjust their mechanical properties reversibly during locomotion. In this paper rolling locomotion of mobile robots based on simple tensegrity structures, consisting of three compressed spatially curved members connected to a continuous net of prestressed tensional members, is discussed. Planar locomotion of these robots is induced by the movement of internal masses. The movement direction can be changed by changing the robot's shape between a cylinder and a truncated cone. The paper focuses on the description of the kinematics of these systems with respect to the shape change. KW - Inverse kinematics KW - Nonholonomic mechanics KW - Tensegrity structure Y1 - 2019 UR - http://212.191.87.54:1616/k16/awrejcewicz/publikacje/T2.pdf SN - 978-83-66287-30-3 SP - 335 EP - 344 PB - Wydawnictwo Politechniki Łódzkiej CY - Łódź, Polen ER - TY - CHAP A1 - Briem, Ulrich T1 - Lebensdauerverhalten verdichteter Seildrähte T2 - Ilmenauer Drahttag 2019 Y1 - 2019 SN - 978-3- 938843-96-3 SP - 73 EP - 82 PB - ISLE Steuerungstechnik und Leistungselektronik CY - Ilmenau 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 - Freni, Angelo A1 - Frazzica, Andrea A1 - Dawoud, Belal A1 - Chmielewski, Stefanie A1 - Calabrese, Luigi A1 - Bonaccorsi, Lucio Maria T1 - Adsorbent coatings for heat pumping applications: Verification of hydrothermal and mechanical stabilities JF - Applied Thermal Engineering N2 - This paper presents novel experimental methods for verification of both hydrothermal and mechanical stabilities of adsorbent coatings. Experiments have been carried out on zeolite-based coatings over aluminum substrates, prepared by a dip-coating technique developed at CNR-ITAE. Hydrothermal aging of several adsorbent coatings is ongoing. Adsorption and structural stability of some samples under test was successfully verified after 35000 aging cycles by isobars measurement and XRD analysis. Mechanical properties of coatings have been evaluated by applying different typologies of static and dynamic mechanical stresses. Results obtained have been compared with those achieved by subjecting adsorbent coatings prepared by Mitsubishi Plastic Incorporation (MPI) to the same characterization protocol. The comparison between the two types of coating returned that MPI coatings posses similar thermal stability and better mechanical strength than CNR-ITAE coatings. KW - Adsorbent coating KW - Adsorption heat pump KW - Hydrothermal stability KW - Mechanical stability Y1 - 2013 U6 - https://doi.org/10.1016/j.applthermaleng.2011.07.010 VL - 50 IS - 2 SP - 1658 EP - 1663 PB - Elsevier ER - TY - JOUR A1 - Frazzica, Andrea A1 - Palomba, Valeria A1 - Dawoud, Belal A1 - Gullì, Giuseppe A1 - Brancato, Vincenza A1 - Sapienza, Alessio A1 - Vasta, Salvatore A1 - Freni, Angelo A1 - Costa, Fabio A1 - Restuccia, Giovanni T1 - Design, realization and testing of an adsorption refrigerator based on activated carbon/ethanol working pair JF - Applied Energy N2 - In the present paper design, realization and testing of a novel small scale adsorption refrigerator prototype based on activated carbon/ethanol working pair is described. Firstly, experimental activity has been carried out for identification of the best performing activated carbon available on the market, through the evaluation of the achievable thermodynamic performance both under air conditioning and refrigeration conditions. Once identified the best performing activated carbon, the design of the adsorber was developed by experimental dynamic performance analysis, carried out by means of the Gravimetric-Large Temperature Jump (G-LTJ) apparatus available at CNR ITAE lab. Finally, the whole 0.5 kW refrigerator prototype was designed and built. First experimental results both under reference air conditioning and refrigeration cycles have been reported, to check the achievable performance. High Specific Cooling Powers (SCPs), 95 W/kg and 50 W/kg, for air conditioning and refrigeration respectively, were obtained, while the COP ranged between 0.09 and 0.11, thus showing an improvement of the current state of the art. (C) 2016 Elsevier Ltd. All rights reserved. KW - Activated carbon KW - ADSORBENTS KW - adsorption KW - Ammonia KW - CARBON KW - CHILLER KW - COOLING SYSTEMS KW - Corrosion KW - DRIVEN KW - Ethanol KW - ETHANOL ADSORPTION KW - PERFORMANCE KW - Refrigeration KW - waste heat Y1 - 2016 U6 - https://doi.org/10.1016/j.apenergy.2016.04.080 VL - 174 SP - 15 EP - 24 PB - Elsevier ER - TY - JOUR A1 - Kalita, Viktor M. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Zorinets, Denis T1 - Effect of single-particle magnetostriction on the shear modulus of compliant magnetoactive elastomers JF - Physical review E N2 - The influence of an external magnetic field on the static shear strain and the effective shear modulus of a magnetoactive elastomer (MAE) is studied theoretically in the framework of a recently introduced approach to the single-particle magnetostriction mechanism [V. M. Kalita et al., Phys. Rev. E 93, 062503 (2016)]. The planar problem of magnetostriction in an MAE with magnetically soft inclusions in the form of a thin disk (platelet) having the magnetic anisotropy in the plane of this disk is solved analytically. An external magnetic field acts with torques on magnetic filler particles, creates mechanical stresses in the vicinity of inclusions, induces shear strain, and increases the effective shear modulus of these composite materials. It is shown that the largest effect of the magnetic field on the effective shear modulus should be expected in MAEs with soft elastomer matrices, where the shear modulus of the matrix is less than the magnetic anisotropy constant of inclusions. It is derived that the effective shear modulus is nonlinearly dependent on the external magnetic field and approaches the saturation value in magnetic fields exceeding the field of particle anisotropy. It is shown that model calculations of the effective shear modulus correspond to a phenomenological definition of effective elastic moduli and magnetoelastic coupling constants. The obtained theoretical results compare well with known experimental data. Determination of effective elastic coefficients in MAEs and their dependence on magnetic field is discussed. The concentration dependence of the effective shear modulus at higher filler concentrations has been estimated using the method of Pade approximants, which predicts that both the absolute and relative changes of the magnetic-field-dependent effective shear modulus will significantly increase with the growing concentration of filler particles. KW - BEHAVIOR KW - composites KW - DEPENDENCE KW - FERROGELS KW - MECHANICAL-PROPERTIES KW - MICROSTRUCTURE KW - Polymer KW - PURE SHEAR KW - RHEOLOGY KW - SENSITIVE ELASTOMERS Y1 - 2017 U6 - https://doi.org/10.1103/PhysRevE.95.032503 VL - 95 IS - 3 PB - American Physical Society 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 - Schwanzer, Peter A1 - Rabl, Hans-Peter A1 - Loders, S. A1 - Seifert, P. A1 - Himmelstoss, S. A1 - Gaderer, Matthias T1 - Difference in the Tailpipe Particle Number by Consideration of Sub-23-nm Particles for Different Injection Settings of a GDI Engine JF - Emission control science and technology N2 - The purpose of this study was to investigate the characteristic of nanoparticles under consideration of sub-23-nm particles from a 1.8-l direct injection (DI) gasoline engine under stoichiometric air/fuel conditions in the exhaust gas system. For future CO2 challenges, the usage of DI-instead of port fuel injection (PFI)-gasoline engines is unavoidable. Therefore, a state of the art particle management program-particle number (PN) system, the Horiba SPCS (2100) with an integrated CPC (condensation particle counter), was recalibrated from a 50% cutoff (D-50%) at 23 nm down to a cutoff at 10 nm and the PCRF (particle concentration reduction factor) for sizes smaller than 23 nm was checked. Two different modal points, out of a representative Real Driving Emission (RDE) cycle, were investigated with both calibrations, D-50%=10 nm and D-50%=23 nm. For these different load points, the fuel pressure (FUP) and the start of injection (SOI) were varied, to represent the difference in the structure and the ratio conc((10 nm))/conc((23 nm)) of the nanoparticle emissions. The particle characterization includes the particle number (PN), the particle size distribution (PSD), and the particle mass (PM). The particle number was measured with Horiba SPCS (2100). The particle size distribution was analyzed with a Grimm differential mobility analyzer (DMA) in combination with a Faraday cup electrometer (FCE). Micro Soot and Pegasor were used to determine the PM, and an optical characterization was done with a 120-kV Phillips CM12 transmission electron microscope (TEM). The position of all particle measurement systems was downstream the three-way catalyst (TWC). The results of this investigation showed that a higher injection pressure decreases the PN (without consideration of sub-23-nm particles) in general. The ratio conc((10 nm))/conc((23 nm)) was therefore higher, because smaller particles, especially ash particles, were less reduced from the FUP. This means higher FUP tends to a higher ratio. For the SOI, the main reasons of the ratio differences were explained by an encroachment between the injection jet and the piston, the valve and the wall. KW - DoE KW - GDI KW - Particle number Y1 - 2019 U6 - https://doi.org/10.1007/s40825-019-0114-1 VL - 5 IS - 1 SP - 7 EP - 22 PB - Springer Nature ER - TY - JOUR A1 - Schwanzer, Peter A1 - Schillinger, Maximilian A1 - Mieslinger, Johann A1 - Walter, Stefanie A1 - Hagen, Gunter A1 - Maerkl, Susanne A1 - Haft, Gerhard A1 - Dietrich, Markus A1 - Moos, Ralf A1 - Gaderer, Matthias A1 - Rabl, Hans-Peter T1 - A Synthetic Ash-Loading Method for Gasoline Particulate Filters with Active Oil Injection JF - SAR International Journal of Engines N2 - To reduce particulate emissions, the use of particulate filters in diesel engines is meanwhile state of the art, while the integration of such systems in gasoline engines is now also necessary in order to comply with today's regulations. Over its lifetime, a gasoline particulate filter (GPF) collects ash components of fuel, lubrication oil, and materials originating from the catalytic coating and from engine abrasion. In the development and application process, synthetic ashing from GPFs is challenging. The ash of the lubrication oil can be increased in various ways, like oil-doped fuel, a separate oil burner, or changes in the piston-cylinder system of the engine. However, these methods show major disadvantages. For this reason, an improved approach is presented in this study, which allows a quick response to changes in combustion (e.g., engine knocking) and producing ash, which is more realistic due to its primary particle size and the density of ash plugs, in a shorter time. Therefore, an approach to accelerate ash loading by active oil injection using a multi-point injection (MPI) system is introduced. With the help of this methodology, an ashing capacity of 1.21 g/h is implemented, which is a high rate compared to other investigations. The primary particle size (evaluated by means of a transmission electron microscope), is in the same size range as those detected at the full-load curve during regular operation. A computer tomographic (CT) analysis of the incinerated particulate filter also shows that a very high density of ash plugs can be realized, which has also been found in the literature for real applications. In addition, with the help of a mass spectrometer (MS) and an intermediate weighing of the particulate filter, the current ash loading of the GPF could be determined with an accuracy of 1%. KW - Ash KW - GDI KW - GPF KW - Particle Y1 - 2021 U6 - https://doi.org/10.4271/03-14-04-0029 SN - 1946-3936 SN - 1946-3944 VL - 14 IS - 4 SP - 493 EP - 506 PB - SAE International ER - TY - JOUR A1 - Schorr, Philipp A1 - Zentner, Lena A1 - Zimmermann, Klaus A1 - Böhm, Valter T1 - Jumping locomotion system based on a multistable tensegrity structure JF - Mechanical systems and signal processing N2 - All known locomotion principles are limited respective to environmental conditions. Often, the occurrence of obstacles or gaps means the break-off for the operating motion systems. For such circumstances, a controllable jumping locomotion is required to cross these barriers. However, this locomotion demands sophisticated requirements to the actuation. The abrupt actuation is commonly realized by high dynamic actuators or complex mechanisms. In this work, a simple solution utilizing the multistability of a compliant tensegrity structure is described. Therefore, a two-dimensional tensegrity structure featuring four stable equilibria is considered. Based on bifurcation analyses a feasible actuation to control the current equilibrium configuration is derived. Changing between selected equilibrium states enables a great difference in potential energy, which yields a jumping motion of the structure. Based on numerical simulations a suitable actuation strategy is chosen to overcome obstacle and steps by jumping forward or backward, respectively. The theoretical approach is examined experimentally with a prototype of the multistable tensegrity structure. (c) 2020 Elsevier Ltd. All rights reserved. All known locomotion principles are limited respective to environmental conditions. Often, the occurrence of obstacles or gaps means the break-off for the operating motion systems. For such circumstances, a controllable jumping locomotion is required to cross these barriers. However, this locomotion demands sophisticated requirements to the actuation. The abrupt actuation is commonly realized by high dynamic actuators or complex mechanisms. In this work, a simple solution utilizing the multistability of a compliant tensegrity structure is described. Therefore, a two-dimensional tensegrity structure featuring four stable equilibria is considered. Based on bifurcation analyses a feasible actuation to control the current equilibrium configuration is derived. Changing between selected equilibrium states enables a great difference in potential energy, which yields a jumping motion of the structure. Based on numerical simulations a suitable actuation strategy is chosen to overcome obstacle and steps by jumping forward or backward, respectively. The theoretical approach is examined experimentally with a prototype of the multistable tensegrity structure. KW - Compliant tensegrity structure KW - Multibody dynamics KW - Multistability KW - Non-classical locomotion Y1 - 2021 U6 - https://doi.org/10.1016/j.ymssp.2020.107384 IS - 152 PB - Elsevier ER - TY - JOUR A1 - Sindersberger, Dirk A1 - Prem, Nina A1 - Monkman, Gareth J. T1 - Self-assembling structure formation in low-density magnetoactive polymers JF - Journal of Applied Polymer Science N2 - The formation of microstructures in magnetoactive polymers (MAPs) is a recently discovered phenomenon found only with very low filler particle concentrations (less than 3 wt %). Due to the degassing process, filler particles collect around an ascending bubble, which dissolves at a certain point leaving particulate rings within the matrix. The formation of toroidal microstructures commences as filler concentration approaches 1 wt %. The development of coherent parallel aligned rings with a compact order continues as particle concentrations increase toward 2 wt %. Between 2 and 3 wt % capillary doublets develop, while mass percentages higher than 3% result in increasing entropy as the random order of particle agglomeration found in higher concentration MAP dominates. Self-structured samples of different filler material and concentrations between 1 and 3 wt % have been investigated using X-ray tomography, where the emerging structures can be observed and visualized. The ring structures resulting from this research represent microinductivities which can be fabricated in a targeted manner, thus enabling new applications in the high-frequency radio field. Furthermore, these anisotropic, but well-organized, structures have magnetic field-dependent implications for optical, thermal, acoustic, and medical applications. KW - composites KW - ELASTOMERS KW - magnetism and magnetic properties KW - Particle KW - PERMEABILITY KW - self-assembly KW - sensors and actuators KW - VISCOELASTIC PROPERTIES KW - X-ray Y1 - 2019 U6 - https://doi.org/10.1002/app.48291 VL - 137 IS - 3 PB - Wiley 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 - CHAP A1 - Bogomolov, Maxim A1 - Kral, Christian A1 - Haumer, Anton A1 - Lomonova, Elena T1 - Modeling of permanent magnet synchronous machine with fractional slot windings T2 - Proceedings IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society ; Ecole de Technologie Superieure de Montreal, Universite du Quebec Montreal, Canada 25 - 28 October, 2012 N2 - This paper focuses on simulation of permanent magnet synchronous machine (PMSM) with fractional-slot windings (FSW) in Modelica. Modeling of the electrical machines with object-oriented approach is shortly described, and a new Modelica library for simulation of electrical machines is introduced. The results of simulation of PMSMs with fractional slot windings are presented and explained. Special attention is paid to the higher harmonics and subharmonics produced by the winding and their influence on machine operation. KW - Concentrated KW - fractional slot KW - harmonics KW - Modelica KW - permanent magnet KW - subharmonics KW - synchronous machines KW - Torque KW - windings Y1 - 2012 SN - 978-1-4673-2421-2 SN - 978-1-4673-2419-9 SN - 978-1-4673-2420-5 U6 - https://doi.org/10.1109/IECON.2012.6388912 SN - 1553-572X SP - 1894 EP - 1899 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Reindl, Andrea A1 - Singer, Thomas A1 - Meier, Hans A1 - Niemetz, Michael A1 - Park, Sangyoung T1 - Framework to Test DC-DC Converters Developed for a Decentralized Battery Management System T2 - 2021 International Conference on Applied Electronics (AE): 7-8 Sept. 2021, Pilsen, Czech Republic N2 - DC- DC converters control the power flow and thus the power distribution between the components on different voltage levels. They are essential for (dis)charging batteries and influence the safety and stability of the entire battery management system (BMS). Therefore, testing the functionality and the reliability of DC-DC converters is crucial. This is especially true for decentralized battery management systems (DBMS), where multiple nodes communicate to collectively control the system. The used DC-DC converters are modified to parameterize them during operation via microcontroller interfaces. Integrating the communication into the control loop requires an analysis of the control behavior due to additional delays. Therefore, this paper proposes a framework to test DC-DC converters considering the control and communication perspectives. The response time, the control accuracy and stability of these DC-DC converters, e.g., under continuous and abrupt load changes, are measured in automated tests. The dedicated software framework simulates the DBMS and stimulates the hardware components (e.g. electronic loads, data acquisition) via respective interfaces (CAN, RS232). This allows the test of various DC-DC converters with flexibly adaptable load and power generation profiles. An initial application validates the test framework by verifying the aforementioned aspects and thus the applicability of a DC-DC converter within the DBMS. KW - Batteries KW - Battery management system KW - Battery management systems KW - Control systems KW - DC-DC converter KW - DC-DC power converters KW - decentralized control KW - hardware in the loop testing KW - object oriented programming KW - Power system stability KW - Python KW - Stability analysis KW - system testing KW - Time measurement Y1 - 2021 U6 - https://doi.org/10.23919/AE51540.2021.9542882 SP - 1 EP - 6 PB - IEEE ER - TY - CHAP A1 - Brkic, Jovan A1 - Ceran, Muaz A1 - Elmoghazy, Mohamed A1 - Kavlak, Ramazan A1 - Haumer, Anton A1 - Kral, Christian T1 - Open Source PhotoVoltaics Library for Systemic Investigations T2 - Proceedings of the 13th International Modelica Conference, March 4-6, 2019, Regensburg, Germany N2 - For the planning of photovoltaic power plants standard software tools are used. Most of these software tools use statistical solar data to determine the overall energy harvest of a photovoltaic plant over one year. The calculations rely on stationary location and ideal boundary conditions, e.g., constant ambient temperature. Even though, for example, shadowing may be considered by standard software, the investigation of untypical configurations and problems cannot be performed by such software, as most configurations cannot be changed by the user. The presented PhotoVoltaics library was developed with the intention to provide a flexible framework for standard and non-standard problems. Particularly, the PhotoVoltaics library can be coupled with other Modelica libraries to perform systemic investigations. An application library, PhotoVoltaics_TGM, is provided as add-on, where measured data of two photovoltaic pants of the TGM in Vienna can be compared with simulation results. This add-on library serves as validation of the PhotoVoltaics library. KW - CELL KW - converter KW - data sheet KW - irradiance KW - maximum power tracking KW - module KW - Photovoltaics KW - plant KW - terrestrial solar model Y1 - 2019 U6 - https://doi.org/10.3384/ecp1915741 SP - 41 EP - 50 PB - Linköing University Electronic Press ER - TY - CHAP A1 - Scharfenberg, Georg A1 - Elis, Ludek A1 - Hofmann, Gerhard T1 - New Design Methodology – Using VHDL-AMS Models to Consider Aging Effects in Automotive Mechatronic Circuits for Safety Relevant Functions T2 - 2019 International Conference on Applied Electronics (AE), 10-11 Sept. 2019, Pilsen, Czech Republic N2 - In this paper a design method for mechatronic functions in an early design phase under consideration of the requirements of functional safety is proposed [14]. The goal of the method is to discover threats for the safety goals and to prove or optimize the diagnostic mechanisms. At the current design process a lifetime endurance test is performed in a late project phase. In order to avoid unexpected late design changes the method should be applied in an early design phase. The method is an additional way to avoid design failures for E/E functions with special focus on aging in the field of functional safety applications. The method is developed out of three standards VDI 2221 methodology for development and construction of technical systems and products [1]), VDI 2206 design methodology for mechatronic systems [2] and the ISO 26262 road vehicles - Functional Safety [3] by using the V-Model. Furthermore, a core element of the design method is simulating aging effects by applying VHDL - AMS. To demonstrate the design methodology a sensor out of the EGAS function is chosen as a safety relevant automotive system. The limitation is the availability of aging data for electrical components. KW - Aging KW - Design methodology KW - Functional Safety KW - Integrated circuit modeling KW - Mechatronic design method KW - Mechatronics KW - Resistor aging KW - safety Y1 - 2019 U6 - https://doi.org/10.23919/AE.2019.8867034 SP - 1 EP - 5 ER - TY - JOUR A1 - Braun, Peter A1 - Durner, Bernhard A1 - Rabl, Hans-Peter A1 - Matysik, Frank-Michael T1 - Investigations on the decomposition of AdBlue urea in the liquid phase at low temperatures by an electrochemically induced pH shift JF - Monatshefte für Chemie N2 - Ammonia-based selective catalytic reduction (SCR) systems are the most widely used technology for reduction of nitrogen oxide emissions from lean-burn engines such as diesel engines. However, at low exhaust temperatures, the SCR process is limited by difficulties in the decomposition of the ammonia precursor urea, which is carried on-board using an aqueous solution "AdBlue". In this study, the decomposition of AdBlue urea induced by electrical current and the resulting associated pH shifts were investigated in a divided cell configuration in the liquid phase. The decomposition was found to be favored in both electrochemical compartments, anodic and cathodic, at temperatures of 60-80 degrees C compared to a reference without electrochemical treatment. In addition to the determination of ammonia contents using an ammonia sensor, IC/HPLC analyses were carried out for each sample. Different side products such as biuret, nitrate, cyanuric acid, ammelide, and others were formed. In the anodic compartment, nitrate formation could be observed due to oxidation of ammonia at the electrode surface. [GRAPHICS] . KW - Ammonia KW - Catalysis KW - CONVERSION KW - Diesel Engine KW - DOPED MN/TIO2 KW - Electrochemistry KW - HYDROLYSIS KW - In situ pH shift KW - NOX KW - OXIDATION KW - PRODUCTS KW - REMOVAL KW - SCR KW - SELECTIVE CATALYTIC-REDUCTION KW - Thermochemistry Y1 - 2019 U6 - https://doi.org/10.1007/s00706-019-02406-6 VL - 150 IS - 9 SP - 1633 EP - 1641 PB - Springer ER - TY - JOUR A1 - Braun, Peter A1 - Rabl, Hans-Peter A1 - Matysik, Frank-Michael T1 - Investigations on the Liquid-Phase Decomposition of AdBlue Urea for the Selective Catalytic Reduction Process JF - Chemie Ingenieur Technik N2 - Difficulties in decomposing AdBlue to ammonia limit the applicability of selective catalytic reduction systems at low exhaust temperatures. Investigations on the decomposition of AdBlue in the liquid phase under elevated pressure at temperatures up to 165 degrees C were carried out. Besides effects of inorganic catalysts, the impact of pH on urea decomposition was examined. After dissolution in aqueous phase, the compounds ZnO, WO3, and MoO3 were found to be effective in liquid-phase AdBlue decomposition. However, the efficiency was dropping significantly over few hours. Decomposition of AdBlue urea was also found to be favored for alkaline and acidic conditions. KW - AdBlue urea KW - Ammonia KW - DeNO(x) KW - EMISSIONS KW - HYDROLYSIS KW - KINETICS KW - Liquid-phase decomposition KW - LOW-TEMPERATURE SCR KW - MODEL KW - NOX KW - Selective catalytic reduction Y1 - 2019 U6 - https://doi.org/10.1002/cite.201800055 VL - 91 IS - 7 SP - 961 EP - 968 PB - Wiley ER - TY - GEN A1 - Weiss, Nils T1 - Vulnerabilities of OBD2 Dongles T2 - RCAR Annual Conference, 2018, Munich, Germany Y1 - 2018 ER - TY - GEN A1 - Weiss, Nils T1 - Vulnerabilities of Connected Cars and beyond T2 - Applied Research Colloquium, 2019, Università Padua, Italy Y1 - 2019 ER - TY - JOUR A1 - Palomba, Valeria A1 - Nowak, Sebastian A1 - Dawoud, Belal A1 - Frazzica, Andrea T1 - Dynamic modelling of Adsorption systems: a comprehensive calibrated dataset for heat pump and storage applications JF - Journal of energy storage N2 - The growing efforts for the development of clean and efficient energy systems require the use of a multi-disciplinary approach and the integration of multiple generation appliances. Among the fields that can be considered enabling technologies, adsorption systems for air conditioning and thermal energy storages, are constantly increasing their maturity. However, for a proper design and integration of such systems, there is the need for a simulation framework that is reliable and computationally convenient. In the present paper, the implementation of a dynamic model for adsorption systems is presented, which includes different components (adsorber, phase changer, sorption materials) and is structured as a library. Modelica language and the commercial software Dymola (R) are used for the analysis. Data for different heat exchangers and working pairs are calibrated using experimental results and the calibrated model is subsequently used for the design of an adsorber based on a plate heat exchanger for thermal energy storage applications. The results proved that the model is fast and can reproduce experimental results with good accuracy, thus being a useful tool for the design and optimization of the different components of sorption systems. KW - CHILLERS KW - DIFFUSION KW - ETHANOL ADSORPTION KW - Optimization KW - PERFORMANCE KW - SCALE KW - simulation KW - THERMAL-ENERGY STORAGE KW - TRANSFORMATION KW - WATER-ADSORPTION Y1 - 2021 U6 - https://doi.org/10.1016/j.est.2020.102148 VL - 33 PB - Elsevier ER - TY - JOUR A1 - Rill, Georg A1 - Bauer, Florian A1 - Kirchbeck, Mathias T1 - VTT - a virtual test truck for modern simulation tasks JF - Vehicle system dynamics N2 - The development of new technologies like advanced driver assistance systems or automated driving requires a flexible simulation environment of sufficient complexity. In general this flexibility is not provided by commercial software packages. This paper presents a three-dimensional and nonlinear hand-made model for heavy commercial vehicles including tractor and trailer as well as tractor and semitrailer combinations that can be used in different simulation environments, as well as in real-time applications. As typical for trucks, the torsional flexibility of the frame and a suspended driver's cabin are taken into account. The design kinematics makes it possible to handle different and quite complex axle suspensions very efficiently. Appropriate force elements are used to model various couplings between tractor and trailer or tractor and semitrailer, respectively. The virtual test truck environment (VTT) coded in ANSI C is extremely portable and can easily be embedded in commercial simulation packages like MATLAB/Simulink. It includes the TMeasy tyre model and offers flexible interfaces to third-party software tools. KW - coupled air springs KW - design Kinematics KW - heavy commercial vehicles KW - MATLAB KW - Simulink KW - TMeasy tyre model KW - vehicle coupling KW - Vehicle modelling Y1 - 2021 U6 - https://doi.org/10.1080/00423114.2019.1705356 VL - 59 IS - 4 SP - 635 EP - 656 PB - Taylor&Francis ER - TY - JOUR A1 - Rill, Georg T1 - Sophisticated but quite simple contact calculation for handling tire models JF - Multibody system dynamics N2 - Handling tire models like Pacejka (Tire and Vehicle Dynamics, 3rd edn., Elsevier, Amsterdam, 2012) or TMeasy (Rill in Proc. of the XV Int. Symp. on Dynamic Problems of Mechanics, Buzios, RJ, Brazil, 2013) consider the contact patch as one coherent plane. As a consequence, the irregularities of a rough road profile must be approximated by an appropriate local road plane that serves as an effective road plane in order to calculate the geometric contact point and the corresponding contact velocities. The Pacejka/SWIFT tire model employs a road enveloping model that generates the effective height and slope by elliptical cams. TMeasy just uses four representative road points for that purpose. In addition, TMeasy replaces the geometric contact point by the static contact point and shifts it finally to the dynamic contact point that represents the point where the contact forces are applied. In doing so, a rather sophisticated but still simple contact calculation is possible. Simulations obtained with a virtual tire test rig and fully nonlinear three-dimensional multibody system models of a motor-scooter and a passenger car demonstrate the potential of this contact approach. KW - Dynamic contact point KW - Effective road plane KW - Geometric contact point KW - Static contact point KW - Tire road contact KW - TMeasy tire model KW - Vehicle modeling Y1 - 2019 U6 - https://doi.org/10.1007/s11044-018-9629-4 VL - 45 IS - 2 SP - 131 EP - 153 PB - Springer Nature ER -