@article{KeinerBreyerSterner, author = {Keiner, Dominik and Breyer, Christian and Sterner, Michael}, title = {Coupling heat and electricity storage technologies for cost and self-consumption optimised residential PV prosumer systems in Germany}, series = {International Journal of Sustainable Energy Planning and Management}, volume = {21}, journal = {International Journal of Sustainable Energy Planning and Management}, publisher = {OJS/PKP}, doi = {10.5278/ijsepm.2019.21.4}, abstract = {Coupling energy sectors within the emerging residential PV prosumer systems is necessary for an optimised use of the houseowners' own produced electricity. But the pure availability of different energy technologies in the system is not enough. By optimising the electricity usage as well as the capacities of PV generators, storage technologies, heat pumps and battery electric vehicles, not only the best solution in a technical point of view can be achieved, the need of finding the most financially beneficial system composition for single-family houses and tenements is possible. The study provides a detailed model for average German single-family houses and tenements and results for the energy transition period until 2050 for the optimised energy systems regarding optimised PV and stationary battery capacities and different heat storage capacities. Most noticeable outcomes can be observed by using a vehicle-to-home car, where a car can mostly take over the tasks of a stationary battery and by introducing a solidarity model using this type of car in tenement systems.}, language = {en} } @article{EstermannNewboroughSterner, author = {Estermann, Thomas and Newborough, Marcus N. and Sterner, Michael}, title = {Power-to-gas systems for absorbing excess solar power in electricity distribution networks}, series = {International Journal of Hydrogen Energy}, volume = {41}, journal = {International Journal of Hydrogen Energy}, number = {32}, publisher = {Elsevier}, doi = {10.1016/j.ijhydene.2016.05.278}, pages = {13950 -- 13959}, abstract = {The feasibility of implementing power-to-gas systems, to absorb surplus solar power from electricity distribution networks and carbon dioxide from biomass anaerobic digestion (AD) plant, in order to produce synthetic methane was investigated for a region of Southern Germany that has a high solar power penetration. The analysis was based on time series electricity data for 2012 from which future load profiles were computed in accordance with the expected installed capacities of solar power across the period 2015-2025. The electrolyser capacity required to absorb 20\% of excess solar energy occurring within the region's low voltage network in 2025 was estimated to be 370 MWe. First order considerations of the region's gas grid, electricity network and existing AD sites suggest that such a deployment could be achieved by installing sub-MW (and some multi-MW) power-to-gas plant at several hundred AD sites.}, language = {en} } @inproceedings{RillButzRill, author = {Rill, Daniel and Butz, Christiane and Rill, Georg}, title = {Dynamic Interaction of Heavy Duty Vehicles and Expansion Joints}, series = {Multibody Dynamics 2019, Proceedings of the 9th ECCOMAS Thematic Conference on Multibody Dynamics}, volume = {53}, booktitle = {Multibody Dynamics 2019, Proceedings of the 9th ECCOMAS Thematic Conference on Multibody Dynamics}, editor = {Kecskem{\´e}thy, Andr{\´e}s and Geu Flores, Francisco}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-030-23131-6}, doi = {10.1007/978-3-030-23132-3_56}, pages = {471 -- 478}, abstract = {The "Smart Bridge (Intelligente Br{\"u}cke)" project cluster, initiated by the German Federal Highway Research Institute (Bundesanstalt f{\"u}r Straßenwesen, BASt) and the Federal Ministry of Transport and Digital Infrastructure (BMVI), focuses on "smart" monitoring devices that allow an efficient and economic maintenance management of bridge infrastructures. Among the participating projects, the one presented herein focuses on the development of a smart expansion joint, to assess the traffic parameters on site. This is achieved by measuring velocity and weight of crossing vehicles. In reference measurements, performed with a three-axle truck and a typical tractor semi-trailer combination with five axles in total, it was shown that the interaction between the vehicle and the expansion joint is highly dynamic and depends on several factors. To get more insight into this dynamic problem, a virtual test rig was set up. Although nearly all vehicle parameters had to be estimated, the simulation results conform very well with the measurements and are robust to vehicle parameter variations. In addition, they indicate a significant influence of the expansion joint dynamic to the peak values of the measured wheel loads, in particular on higher driving velocities. By compensating the relevant dynamic effects in the measurements, a "smart" data processing algorithm makes it possible to determine the actual vehicle weights in random traffic with reliability and appropriate accuracy.}, language = {en} } @inproceedings{BuschmannBriem, author = {Buschmann, Knut and Briem, Ulrich}, title = {Ultra Deep Temperature Behaviour of Wire Rope and Rope Wires}, series = {Proceedings of the OIPEEC Conference, La Rochelle, France, 12th - 15th March 2019}, booktitle = {Proceedings of the OIPEEC Conference, La Rochelle, France, 12th - 15th March 2019}, editor = {Dohm, Martin}, abstract = {Mobile cranes are regularly operated in regions which experience ultra deep operating temperatures of down to -60?C (-76?F). In safety regulated work environments crane operations will be suspended simply because the lowest wire rope working temperature stated in the applicable standards is -40?C/F. Examples of ultra deep temperature wire rope application are shown in Figure 1.1 and 1.3. It should be noted that this paper is written in conjunction with a paper written by the co-author Ulrich Briem titled "Fatigue Behaviour of Rope Wires", presented and published in unison with this one. In order to analyze the behaviour under ultra deep temperature conditions, tests on wire rope as well as on rope wires were carried out. In the following, static tensile and bending test results with rope and rope wires will be reported, which were carried out in conditions of down to -95?C (-139?F) as well as at room temperature. The conclusion is that the results of these tests can be adopted to crane wire rope as well.}, language = {en} } @inproceedings{HofmeisterKrebsSchickhuberetal., author = {Hofmeister, Justus and Krebs, Stefan and Schickhuber, Gerald and Scharfenberg, Georg}, title = {Design and development of a Pico Hydro turbine system for the use in developing countries}, series = {2015 5th International Youth Conference on Energy (IYCE), 27-30 May 2015, Pisa, Italy}, booktitle = {2015 5th International Youth Conference on Energy (IYCE), 27-30 May 2015, Pisa, Italy}, publisher = {IEEE}, doi = {10.1109/IYCE.2015.7180767}, pages = {1 -- 7}, abstract = {In Sub-Saharan Africa less than 10\% of the rural population has access to electricity [1]. Stand-alone power systems (SPS) can be a solution to the problem of the lack of electricity, which highlights challenges such as modules installation costs as well as the sufficient knowledge required for installing, maintaining and operating such systems. With this fact in mind, a 250 W Low Head turbine system was developed and optimized to have the advantage of the simplicity of installation and a construction from readily available materials. This design scores the electrical efficiency of 60\%, reduces manufacturing unit coast to 130 € and takes into account the necessity of providing a clear and simple manual describing the manufacturing and installation. A better version of the load controller, using a microcomputer is under current development. Mounting of the system have been simplified to reduce the amount of construction material required to provide uninterrupted 230 V at 50 Hz AC or optional 12 V DC power supply. Current efforts aim on transferring the required mechanical and electrical knowledge for building, programming, installing and maintaining such system to schools in targeted countries. This project doesn't only provide people in rural developing countries a gleam of hope to catch up with the developed countries, but also helps students to use their theoretical knowledge to realize practical applications.}, language = {en} } @article{FederrathMottokPloessletal., author = {Federrath, H. and Mottok, J{\"u}rgen and Pl{\"o}ßl, K. and V{\"o}lkl, Thomas}, title = {Automotive safety and security}, series = {Jahresr{\"u}ckblick 2007 des Bayerischen IT-Sicherheitsclusters}, journal = {Jahresr{\"u}ckblick 2007 des Bayerischen IT-Sicherheitsclusters}, pages = {25}, language = {de} } @article{SykoraMarkovaDiamantidis, author = {S{\´y}kora, Miroslav and Markova, Jana and Diamantidis, Dimitris}, title = {Bayesian network application for the risk assessment of existing energy production units}, series = {Reliability Engineering \& System Safety}, volume = {169}, journal = {Reliability Engineering \& System Safety}, number = {January}, publisher = {Elsevier}, doi = {10.1016/j.ress.2017.09.006}, pages = {312 -- 320}, abstract = {The assessment of existing infrastructures in the energy sector is of great economic significance worldwide. Fossil power stations are reaching their design service life and rational decisions concerning extensions of service life, maintenance and replacements of devices should be based on updated information of the actual conditions of the energy devices and their components, and on cost-benefit analysis using risk analysis and probabilistic optimisation procedures. The contribution provides an integrated framework for probabilistic reliability and risk assessment of existing energy production units considering availability and human safety criteria. An extensive case study focused on risks of an energy production unit in a fossil power station is provided to support practical applications. A Bayesian network is thereby implemented to assess the risks of the selected production unit. Special emphasis is given to the input data consisting of failure rates obtained from recorded data and expert judgements. The influence of uncertainties in the considered performance indicators on the availability of the unit is analysed. It is shown that a reasonably simplified framework can provide a valuable assessment of the influence of individual devices and their components on availability and societal risk, identifying thus the major risk contributors. (C) 2017 Elsevier Ltd. All rights reserved.}, language = {en} } @article{WeberHaug, author = {Weber, Karsten and Haug, Sonja}, title = {Ist automatisiertes Fahren nachhaltig?}, series = {TATuP - Zeitschrift f{\"u}r Technikfolgenabsch{\"a}tzung in Theorie und Praxis}, volume = {27}, journal = {TATuP - Zeitschrift f{\"u}r Technikfolgenabsch{\"a}tzung in Theorie und Praxis}, number = {2}, publisher = {Karlsruhe Institute of Technology (KIT)}, doi = {10.14512/tatup.27.2.16}, pages = {16 -- 22}, abstract = {Automatisiertes Fahren st{\"o}ßt derzeit noch auf große Skepsis. Eine disruptive Strategie bei der Einf{\"u}hrung (voll-)automatisierten Fahrens k{\"o}nnte daher auf fehlende Akzeptanz treffen. Um dem zu entgehen, laufen evolution{\"a}re Strategien darauf hinaus, durch die Entwicklung adaptiver Fahrassistenzsysteme Vertrautheit, Vertrauen und damit Akzeptanz bei den prospektiven NutzerInnen zu schaffen. Erste Ergebnisse einer Pilotstudie lassen jedoch Zweifel an der Nachhaltigkeit dieser Strategie aufkommen.}, language = {de} } @inproceedings{KeimNonnLenzetal., author = {Keim, Vincent and Nonn, Aida and Lenz, D. and Brinnel, Viktoria and M{\"u}nstermann, Sebastian}, title = {Simulation of the ductile fracture behaviour of high toughness pipeline steels using combined damage models}, series = {Proceedings of the conference on Technology for future and ageing piplines, Ghent, Belgium}, booktitle = {Proceedings of the conference on Technology for future and ageing piplines, Ghent, Belgium}, language = {en} } @inproceedings{NonnKalwa, author = {Nonn, Aida and Kalwa, Christoph}, title = {Simulation of ductile crack propagation in high-strength pipeline steel using damage models}, series = {9th International Pipeline Conference 2012 (IPC 2012), Calgary, Canada}, booktitle = {9th International Pipeline Conference 2012 (IPC 2012), Calgary, Canada}, doi = {10.1115/IPC2012-90653}, pages = {7}, abstract = {The performance of engineering design of high-strength steel pipelines has revealed the necessity to revise current design procedures. Therefore, an improved and detailed comprehension of fracture mechanisms and development of failure prediction tools are required in order to derive new design criteria. In last decades the most successful failure prediction tools for steel structures subjected to various type of loading can be encountered in the field of damage mechanics. This paper aims to describe ductile fracture behavior of high-strength steel pipelines by applying three different damage models, Gurson-Tvergaard-Needelman (GTN), Fracture Locus Curve (FLC) and Cohesive Zone (CZ). These models are evaluated regarding their capability to estimate ductile crack propagation in laboratory specimens and linepipe components without adjusting the calibrated parameters. It can be shown that appropriate parameter sets can be identified to reproduce load-deformation and fracture resistance curves accurately. The strain rate effect on the fracture behavior is examined by dynamic tests on the BDWT specimens. Finally, the shortcomings of the applied models are pointed out with the reference to possible extensions and modifications.}, language = {en} } @article{LeeSchubertOoietal., author = {Lee, Wai-Kong and Schubert, Martin J. W. and Ooi, Boon Yaik and Ho, Stanley Jian-Qin}, title = {Multi-source energy harvesting and storage for floating wireless sensor network nodes with Long Range Communication Capability}, series = {IEEE Transactions on Industry Applications}, volume = {54}, journal = {IEEE Transactions on Industry Applications}, number = {3}, publisher = {IEEE}, doi = {10.1109/TIA.2018.2799}, pages = {2606 -- 2615}, abstract = {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.}, language = {en} } @article{HaugVetterWeber, author = {Haug, Sonja and Vetter, Miriam and Weber, Karsten}, title = {Geb{\"a}udesanierung zwischen Energieeffizienz und Sozialvertr{\"a}glichkeit}, series = {TATuP - Zeitschrift f{\"u}r Technikfolgenabsch{\"a}tzung in Theorie und Praxis}, volume = {29}, journal = {TATuP - Zeitschrift f{\"u}r Technikfolgenabsch{\"a}tzung in Theorie und Praxis}, number = {3}, publisher = {oekom-Verlag}, issn = {2567-8833}, doi = {10.14512/tatup.29.3.56}, pages = {56 -- 63}, abstract = {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 sozialvertr{\"a}glichen Sanierung wurde jeweils ein hohes Maß an Energieeffizienz bei den technischen L{\"o}sungen ange-strebt. Haushaltsbefragungen und qualitative Interviews zeigen die hohe Akzeptanz von Sanierungsmaßnahmen, sofern die Senkung der Energiekosten die erh{\"o}hte Miete kompensiert. Abschließend werden Akzeptanzfaktoren wie Partizipation, Vertrauen, Sozialvertr{\"a}glichkeit und Autarkie er{\"o}rtert.}, subject = {Altbaumodernisierung}, language = {de} } @inproceedings{WeberHaug, author = {Weber, Karsten and Haug, Sonja}, title = {Automatisiertes Fahren: Evolution{\"a}re Weiterentwicklung statt Disruption}, series = {Vierte Jahreskonferenz des Netzwerks INDIGO zum Thema "Mobilit{\"a}t", 23.11.2018, , TH Deggendorf}, booktitle = {Vierte Jahreskonferenz des Netzwerks INDIGO zum Thema "Mobilit{\"a}t", 23.11.2018, , TH Deggendorf}, language = {de} } @inproceedings{DeNiklasRooneyetal., author = {De, Sangita and Niklas, Michael and Rooney, Brian and Mottok, J{\"u}rgen and Brada, Premek}, title = {Towards Translation of Semantics of Automotive Interface Description Models from Franca to AUTOSAR Frameworks}, series = {2019 International Conference on Applied Electronics (AE), 10-11 Sept. 2019, Pilsen, Czech Republic}, booktitle = {2019 International Conference on Applied Electronics (AE), 10-11 Sept. 2019, Pilsen, Czech Republic}, publisher = {University of West Bohemia}, doi = {10.23919/AE.2019.8867018}, pages = {1 -- 6}, abstract = {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.}, language = {en} } @article{SelmairMaurerLaietal., author = {Selmair, Maximilian and Maurer, Tobias and Lai, Chun-Han and Grant, David}, title = {Enhancing the efficiency of charging \& parking processes for Autonomous Mobile Robot fleets}, series = {Journal of Power Sources}, volume = {521}, journal = {Journal of Power Sources}, number = {3}, publisher = {Elsevier}, doi = {10.1016/j.jpowsour.2021.230894}, abstract = {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.}, language = {en} } @inproceedings{JupkeReindlMeieretal., author = {Jupke, Michael and Reindl, Andrea and Meier, Hans and Niemetz, Michael}, title = {Bidirectional DC-DC Converter with Digital Droop Parameterization}, series = {26th 2021 International Conference on Applied Electronics (AE): 7-8 Sept. 2021 Pilsen, Czech Republic}, booktitle = {26th 2021 International Conference on Applied Electronics (AE): 7-8 Sept. 2021 Pilsen, Czech Republic}, editor = {Pinker, Jiř{\´i}}, publisher = {Institute of Electrical and Electronics Engineers}, isbn = {978-80-261-0972-3}, doi = {10.23919/AE51540.2021.9542920}, pages = {1 -- 6}, abstract = {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.}, language = {en} } @inproceedings{BoccaraDiamantidisSykora, author = {Boccara, R. and Diamantidis, Dimitris and S{\´y}kora, Miroslav}, title = {Optimal design of ground-mounted solar systems}, series = {Safety and reliability : methodology and applications : proceedings of the European Safety and Reliability Conference, ESREL 2014, Wrocław, Poland, 14-18 September 2014}, booktitle = {Safety and reliability : methodology and applications : proceedings of the European Safety and Reliability Conference, ESREL 2014, Wrocław, Poland, 14-18 September 2014}, publisher = {CRC Press}, address = {Boca Raton}, isbn = {978-1-138-02681-0}, pages = {2175 -- 2181}, abstract = {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.}, language = {en} } @inproceedings{KasparKleinerRabl, author = {Kaspar, Marcel and Kleiner, Florian and Rabl, Hans-Peter}, title = {Online-Analyse und Optimierung der Schmier{\"o}lverd{\"u}nnung bei direkteinspritzenden Ottomotoren}, series = {7. VDI-Fachtagung mit Fachausstellung Zylinderlaufbahn, Kolben, Pleuel : Baden-Baden, 03. und 04. Juni 2014}, booktitle = {7. VDI-Fachtagung mit Fachausstellung Zylinderlaufbahn, Kolben, Pleuel : Baden-Baden, 03. und 04. Juni 2014}, publisher = {VDI-Verlag}, address = {D{\"u}sseldorf}, isbn = {978-3-18-092230-0}, pages = {65 -- 77}, abstract = {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 Motor{\"o}l vermischen kann. Eine Verst{\"a}rkung dieses Kraftstoffauftrags ist unter anderem der Verschiebung der Motorbetriebspunkte zu h{\"o}heren Mitteldr{\"u}cken und damit einem Wirkungsgrad optimaleren Betrieb geschuldet. Eine Ver{\"a}nderung der physikalischen und chemischen Eigenschaften des Motor{\"o}ls durch die Verd{\"u}nnung mit Kraftstoff ist die Folge. Durch die Verringerung der Viskosit{\"a}t des Motor{\"o}ls kann es zu einer verminderten Schmierwirkung des {\"O}ls kommen, die im schlimmsten Fall zur Sch{\"a}digung des Motors f{\"u}hrt. 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 Schmier{\"o}lverd{\"u}nnung dar. Durch neue Entwicklungstrends bei Ottomotoren ist es jedoch unbedingt notwendig, die Mechanismen des Kraftstoffein- und -austrags in das und aus dem Motor{\"o}l genauer zu untersuchen. Mit der an der OTH Regensburg neu entwickelten Messtechnik wurde eine Vorgehensweise erarbeitet, mit der die zeitlichen Verl{\"a}ufe des Kraftstoffein- und -austragsverhaltens bei Ottomotoren quantitativ in kurzer Zeit bestimmt und optimiert werden k{\"o}nnen. 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.}, language = {de} } @article{KeimMarxNonnetal., author = {Keim, Vincent and Marx, P. and Nonn, Aida and M{\"u}nstermann, Sebastian}, title = {Fluid-structure-interaction modeling of dynamic fracture propagation in pipelines transporting natural gases and CO2-mixtures}, series = {International Journal of Pressure Vessels and Piping}, volume = {175}, journal = {International Journal of Pressure Vessels and Piping}, number = {August}, publisher = {Elsevier}, doi = {10.1016/j.ijpvp.2019.103934}, abstract = {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.}, subject = {Fluid-Struktur-Wechselwirkung}, language = {en} } @article{KeimNonnMuenstermann, author = {Keim, Vincent and Nonn, Aida and M{\"u}nstermann, Sebastian}, title = {Application of the modified Bai-Wierzbicki model for the prediction of ductile fracture in pipelines}, series = {International Journal of Pressure Vessels and Piping}, volume = {171}, journal = {International Journal of Pressure Vessels and Piping}, number = {March}, publisher = {Elsevier}, doi = {10.1016/j.ijpvp.2019.02.010}, pages = {104 -- 116}, abstract = {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.}, language = {en} }