@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} } @inproceedings{VoellingNonnSchneider, author = {V{\"o}lling, Alexander and Nonn, Aida and Schneider, Ingo}, title = {Anwendung des Koh{\"a}sivzonenmodells zur Abbildung von duktilem dynamischen Rissfortschritt in Gasfernleitungen}, series = {45. Tagung des AK Bruch, Berlin, Germany}, booktitle = {45. Tagung des AK Bruch, Berlin, Germany}, pages = {253 -- 262}, subject = {Ferngasleitung}, language = {de} } @inproceedings{NonnWesselSchmidt, author = {Nonn, Aida and Wessel, Waldemar and Schmidt, Tanja}, title = {Application of finite element analysis for assessment of fracture behavior of modern high toughness seamless pipeline steels}, series = {23rd International Society of Offshore and Polar Engineering 2013 (ISOPE 2013), Anchorage, USA}, booktitle = {23rd International Society of Offshore and Polar Engineering 2013 (ISOPE 2013), Anchorage, USA}, doi = {10.13140/2.1.4239.2322}, abstract = {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.}, subject = {Rissfortschritt}, language = {en} } @inproceedings{KofianiNonnWierzbickietal., author = {Kofiani, Kirki and Nonn, Aida and Wierzbicki, Tomasz and Kalwa, Christoph and Walters, Carey}, title = {Experiments and fracture modeling of high-strength pipelines for high and low stress triaxiality}, series = {22nd International Society of Offshore and Polar Engineering 2012 (ISOPE 2012), Rhodes, Greece, June 2012}, booktitle = {22nd International Society of Offshore and Polar Engineering 2012 (ISOPE 2012), Rhodes, Greece, June 2012}, abstract = {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.}, language = {en} } @inproceedings{NonnKalwa, author = {Nonn, Aida and Kalwa, Christoph}, title = {Failure modeling of pipeline X100 Material in temperature transition region}, series = {22nd International Society of Offshore and Polar Engineering 2012 (ISOPE 2012), Rhodes, Greece}, booktitle = {22nd International Society of Offshore and Polar Engineering 2012 (ISOPE 2012), Rhodes, Greece}, abstract = {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.}, language = {en} } @inproceedings{NonnKalwa, author = {Nonn, Aida and Kalwa, Christoph}, title = {The effect of microstructure, strain hardening and strain rate on the fracture behavior of high strength pipeline steels}, series = {2nd International Conference on Material Modelling (ICMM2), 31th August - 2nd September, 2011 at Mines Paris Tech, France}, booktitle = {2nd International Conference on Material Modelling (ICMM2), 31th August - 2nd September, 2011 at Mines Paris Tech, France}, language = {en} } @inproceedings{NonnKalwa, author = {Nonn, Aida and Kalwa, Christoph}, title = {Application of damage mechanics approach for crack propagation in pipeline}, series = {19th Biennial Joint Technical Meeting (JTM) on Pipeline Research, April 29 - May 3, 2013, Sydney, Australia}, booktitle = {19th Biennial Joint Technical Meeting (JTM) on Pipeline Research, April 29 - May 3, 2013, Sydney, Australia}, language = {en} } @inproceedings{NonnKalwa, author = {Nonn, Aida and Kalwa, Christoph}, title = {Application of probabilistic fracture mechanics for safety assessment of longitudinally welded linepipes}, series = {6th Pipeline Technology Conference (2013), Ostend, Belgium}, booktitle = {6th Pipeline Technology Conference (2013), Ostend, Belgium}, language = {en} } @techreport{NeidhartLerchWiesingeretal., author = {Neidhart, Thomas and Lerch, Maximilian and Wiesinger, Doris and Zrenner, Louis}, title = {Kompakte {\"U}bertragungsleitungen f{\"u}r hohe Gleichspannungen: Langzeituntersuchungen an einer erdverlegten Versuchsanlage}, doi = {10.35096/othr/pub-2173}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-21730}, pages = {62, 58}, abstract = {Durch den Ausstieg aus der Verstromung fossiler Energietr{\"a}ger und der daraus resultierenden dezentralen Stromerzeugung ist ein Aus- bzw. Umbau des deutschen {\"U}bertragungsnetzes erforderlich. Weil aus der dezentralen Energieerzeugung große Trassenl{\"a}ngen resultieren, welche bei Wechselstrom zu Blindleistungsproblematiken f{\"u}hren, wird dort vermehrt auf Hochspannungs-Gleichstrom-{\"U}bertragung zur{\"u}ckgegriffen. Im Rahmen des Forschungsprojekts DC CTL DBI (direct current compact transmission line - directly buried investigastions) wurde ein gasisolierte HG{\"U}-Leiter (GIL) erdverlegt und bei st{\"a}ndigem Monitoring {\"u}ber umfangreiche Sensorik einem Langzeitversuch unterzogen. Anstelle einer klassischen Sandbettung kam ein zeitweise fließf{\"a}higer, selbstverdichtender Verf{\"u}llbaustoff (ZFSV) zum Einsatz. Somit k{\"o}nnen Sch{\"a}den an der {\"U}bertragungsleitung infolge Verdichtungsaufwand vermieden und gleichzeitig bessere Bodeneigenschaften hinsichtlich der W{\"a}rme- und Wassertransportprozesse erreicht werden.}, language = {de} } @incollection{SternerStadler, author = {Sterner, Michael and Stadler, Ingo}, title = {Energiespeicher im Wandel der Zeit}, series = {Energiespeicher - Bedarf, Technologien, Integration}, booktitle = {Energiespeicher - Bedarf, Technologien, Integration}, edition = {2. Auflage}, publisher = {Springer Vieweg}, address = {Berlin ; Heidelberg}, isbn = {978-3-662-48893-5}, doi = {10.1007/978-3-662-48893-5_1}, pages = {3 -- 24}, subject = {Energiespeicher}, language = {de} } @incollection{SternerStadlerEckertetal., author = {Sterner, Michael and Stadler, Ingo and Eckert, Fabian and Thema, Martin}, title = {Speicherintegration in einzelnen Energiesektoren}, series = {Energiespeicher - Bedarf, Technologien, Integration}, booktitle = {Energiespeicher - Bedarf, Technologien, Integration}, edition = {2. Auflage}, publisher = {Springer Vieweg}, address = {Berlin ; Heidelberg}, isbn = {978-3-662-48893-5}, doi = {10.1007/978-3-662-48893-5_13}, pages = {685 -- 767}, subject = {Energiespeicher}, language = {de} } @incollection{SternerBauer, author = {Sterner, Michael and Bauer, Franz}, title = {Definition und Klassifizierung von Energiespeichern}, series = {Energiespeicher - Bedarf, Technologien, Integration}, booktitle = {Energiespeicher - Bedarf, Technologien, Integration}, edition = {2. Auflage}, publisher = {Springer Vieweg}, address = {Berlin ; Heidelberg}, isbn = {978-3-662-48892-8}, doi = {10.1007/978-3-662-48893-5_2}, pages = {25 -- 49}, subject = {Energiespeicher}, language = {de} } @inproceedings{HopfenspergerDaubnerHerrmannetal., author = {Hopfensperger, Bernhard and Daubner, Andreas and Herrmann, Fabian and Hopkins, Andrew and Mellor, Phil}, title = {Investigation of Shifted PWM Methods for a Dual Three-Phase System to Reduce Capacitor RMS Current}, series = {PCIM Europe Digital Days 2020: International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management: 07.-08.07.2020, Online [proceedings]}, booktitle = {PCIM Europe Digital Days 2020: International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management: 07.-08.07.2020, Online [proceedings]}, publisher = {VDE-Verlag}, address = {Berlin, Offenbach}, isbn = {978-3-8007-5245-4}, pages = {124 -- 131}, abstract = {Mild hybrid automotive topologies containing a 48V high power (>15 kW) electric drive system demand a high integration of power electronics and electrical machine. A multi-phase motor winding topology helps to keep the per-phase operating currents to a reasonable level. Close integration and multi-phase system have led to a drive system with dual 3-phase systems supplied by a common 48V DC-link, which allows to shift PWM patterns for reduction of DC-link capacitor ripple current and size. This paper derives some basic rules for combinations of common PWM methods for dual 3-phase systems without magnetic cross-coupling. Experimental measurements verify simulated results.}, subject = {Elektroantrieb}, language = {en} } @inproceedings{GrauvoglStauderHopfenspergeretal., author = {Grauvogl, Dominik and Stauder, Peter and Hopfensperger, Bernhard and Gerling, Dieter}, title = {Multiphysics Design of a Wound Field Synchronous Machine with Magnetic Asymmetry}, series = {Proceedings of the 2021 IEEE International Electric Machines \& Drives Conference (IEMDC): 17-20 May 2021, Hartford, CT, USA}, booktitle = {Proceedings of the 2021 IEEE International Electric Machines \& Drives Conference (IEMDC): 17-20 May 2021, Hartford, CT, USA}, doi = {10.1109/IEMDC47953.2021.9449564}, abstract = {In this paper a multiphysics development method is used for designing a novel wound field synchronous machine of the future generation of high voltage traction drives. This method covers the domains of electromagnetics, the mechanical strength, thermal behavior and the magnetic noise. It is shown that the proposed novel asymmetric design with a circular flux barrier in combination with an asymmetric pole offset is fulfilling the requirements according to performance and torque ripple. A fatigue strength rotor mechanic concept is included. A hybrid cooling concept consisting of a water jacket cooled stator and air cooled rotor ensures the needed continuous power. Unacceptable noise levels are excluded by investigating the equivalent radiated power (ERP) level due to radial forces in the air gap. Finally, the multi-physical workflow resulted in a fully developed component with a high degree of maturity.}, language = {en} } @inproceedings{GrauvoglKrabinskiStauderetal., author = {Grauvogl, Dominik and Krabinski, Jeffrey and Stauder, Peter and Hopfensperger, Bernhard and Gerling, Dieter}, title = {NVH Comparison of a Novel Wound Field Synchronous Machine with Magnetic Asymmetry with a PSM for a HV Electric Drive}, series = {2021 JSAE Annual Congress (Spring) Proceedings; online meeting (No.76-21)}, booktitle = {2021 JSAE Annual Congress (Spring) Proceedings; online meeting (No.76-21)}, publisher = {JSAE}, abstract = {This paper shows how magnetic noises can be reduced with a wound field synchronous machine (WFSM) with magnetic asymmetry compared to a permanent magnet synchronous machine (PSM), operating at base speed range and full load. In order to reproduce a real noise behavior, the two rotor types are operated in a complete electric drive unit (EDU) consisting of an electric motor, gearbox, inverter and overall housing. In the concept study, the noise characteristics of the two electric machines is evaluated and compared via mechanical finite element method (FEM) simulations using the equivalent radiated power (ERP) level and Campbell diagrams. Furthermore, it is shown that critical frequency orders can already be identified by the analysis of the magnetic force density from the electromagnetic design without computationally intensive ERP calculations. In this context, the ERP investigations have shown that the unique feature of the magnetically asymmetric WFSM is the reduction of the slot harmonics. At the current state of the art, the slot harmonics can only be reduced with a rotor skewing. The disadvantage of this is a reduction in performance and a more expensive production. It is also remarkable that the magnetic asymmetry reduces the slot harmonics more than the rotor skewing in the PSM. In addition, both machines are still considered with a short-pitched stator winding to optimize the overall noise level by reducing the 24th frequency order.}, subject = {Elektroantrieb}, language = {en} } @inproceedings{LangSteinbornSteffensetal., author = {Lang, Christian and Steinborn, Florian and Steffens, Oliver and Lang, Elmar Wolfgang}, title = {Electricity Load Forecasting - An Evaluation of Simple 1D-CNN Network Structures}, series = {International Conference on Time Series and Forecasting (ITISE 2019), Proceedings of Papers Vol. 2, 25-27 September 2019, Granada (Spain)}, booktitle = {International Conference on Time Series and Forecasting (ITISE 2019), Proceedings of Papers Vol. 2, 25-27 September 2019, Granada (Spain)}, isbn = {978-84-17970-78-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-16649}, pages = {797 -- 806}, abstract = {This paper presents a convolutional neural network (CNN)which can be used for forecasting electricity load profiles 36 hours intothe future. In contrast to well established CNN architectures, the inputdata is one-dimensional. A parameter scanning of network parameters isconducted in order to gain information about the influence of the kernelsize, number of filters, and dense size. The results show that a goodforecast quality can already be achieved with basic CNN architectures.The method works not only for smooth sum loads of many hundredconsumers, but also for the load of apartment buildings}, language = {en} } @incollection{LangSteinbornSteffensetal., author = {Lang, Christian and Steinborn, Florian and Steffens, Oliver and Lang, Elmar Wolfgang}, title = {Applying a 1D-CNN Network to Electricity Load Forecasting}, series = {Theory and Applications of Time Series Analysis}, booktitle = {Theory and Applications of Time Series Analysis}, editor = {Valenzuela, O. and Rojas, F. and Herrera, L.J. and Pomares, H. and Rojas, I.}, publisher = {Springer}, doi = {10.1007/978-3-030-56219-9_14}, pages = {205 -- 218}, abstract = {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.}, language = {en} } @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{ArrietaCastroWeberRill, author = {Arrieta Castro, Abel and Weber, Hans Ingo and Rill, Georg}, title = {Design an integrate vehicle control based-on hierarchical architecture for improve the performance of ground vehicles}, series = {COBEM2015 : 23rd ABCM International Congress of Mechanical Engineering, December 6-11, 2015, Rio de Janeiro, RJ, Brazi}, booktitle = {COBEM2015 : 23rd ABCM International Congress of Mechanical Engineering, December 6-11, 2015, Rio de Janeiro, RJ, Brazi}, organization = {Associa{\c{c}}{\~a}o Brasileira de Engenharia e Ci{\^e}ncias Mec{\^a}nicas}, doi = {10.20906/cps/cob-2015-1970}, language = {en} } @inproceedings{DessortChucholowskiRill, author = {Dessort, Ronnie and Chucholowski, Cornelius and Rill, Georg}, title = {Parametrical approach for modeling of tire forces and torques in TMeasy 5}, series = {16. Internationales Stuttgarter Symposium, Automobil- und Motorentechnik, Bd. 1}, booktitle = {16. Internationales Stuttgarter Symposium, Automobil- und Motorentechnik, Bd. 1}, editor = {Bargende, Michael and Reuss, Hans-Christian and Wiedemann, Jochen}, publisher = {Springer}, address = {Wiesbaden}, isbn = {978-3-658-13254-5}, doi = {10.1007/978-3-658-13255-2_31}, pages = {435 -- 449}, abstract = {For the dynamic simulation of on-road vehicles, the model-element "tire/road" is of special importance, according to its influence on the achievable results. Sufficient description of the interaction between tire and road is one of the most challenging tasks of vehicle modeling. Two groups of tire models can be classified: handling models and structural or high-frequency models. Usually, various assumptions are made in modeling vehicles as multibody systems. Therefore, in the interest of balanced modeling, the precision of the complete vehicle model should stand in reasonable relation to the performance of the applied tire model. Handling tire models are characterized by a useful compromise between user friendliness, model complexity, and efficiency in computation time on the one hand, and precision in representation on the other hand.}, language = {en} } @inproceedings{Briem, author = {Briem, Ulrich}, title = {Fatigue Behaviour of 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}, publisher = {OIPEEC}, abstract = {The rope curve line of a tensioned rope can be described by means of the catenary curve. Opposed to that, the curved line of a free bent rope cannot be described by an analytical function. Practical applications of free bending are for example at tail ropes at the bottom of shaft in rope drives with traction sheaves. The question whether the maximum diameter of rope loop is small enough for the diameter of the shaft is highly interesting. In [1] a method was presented to calculate the curved line of free bent ropes numerically by help of energy methods. An analytical description of rope curve line would be very helpful. Beginning with the structure of a rope curve line of tensioned rope (catenary curve) and considering the influence of bending stiffness, the structure of an analytical equation for the curve line of a free bent rope will be developed. The main focus of this paper is to develop and to describe the structure of such an analytical equation. To get a first idea about the values of the constants in that analytical equation a few test results were evaluated. But these equations consider the static rope behavior only. Due to dynamic effects in the rope while running through the loop at the bottom of a shaft, pendulousness of the tail rope occurs.}, language = {en} } @inproceedings{Briem2019, author = {Briem, Ulrich}, title = {Mathematical Approach to Curve Line of free bent Ropes}, 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}, publisher = {OIPEEC}, year = {2019}, abstract = {The rope curve line of a tensioned rope can be described by means of the catenary curve. Opposed to that, the curved line of a free bent rope cannot be described by an analytical function. Practical applications of free bending are for example at tail ropes at the bottom of shaft in rope drives with traction sheaves. The question whether the maximum diameter of rope loop is small enough for the diameter of the shaft is highly interesting. In [1] a method was presented to calculate the curved line of free bent ropes numerically by help of energy methods. An analytical description of rope curve line would be very helpful. Beginning with the structure of a rope curve line of tensioned rope (catenary curve) and considering the influence of bending stiffness, the structure of an analytical equation for the curve line of a free bent rope will be developed. The main focus of this paper is to develop and to describe the structure of such an analytical equation. To get a first idea about the values of the constants in that analytical equation a few test results were evaluated. But these equations consider the static rope behavior only. Due to dynamic effects in the rope while running through the loop at the bottom of a shaft, pendulousness of the tail rope occurs.}, 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} } @article{LangMonkman, author = {Lang, A. and Monkman, Gareth J.}, title = {An analysis of the electrical capacitance between two conducting spheres}, series = {Journal of Electrostatics}, volume = {108}, journal = {Journal of Electrostatics}, publisher = {Elsevier}, doi = {10.1016/j.elstat.2020.103518}, abstract = {Many modern composites consist of dielectric polymer matrices containing embedded spherical particles. These particles can be electrically conducting and often have magnetic properties. In order to accurately model and simulate such materials, precise calculation of the electrical capacitance between identically sized spheres is required. This is of particular relevance at microscopic dimensions where many smart material-based micro devices are concerned. This may appear trivial for a small number of particles. However, many methods or their analysis appear to be questionable or not applicable at reduced dimensions. In this work, the various methods of analysis are scrutinized before being compared with both simulation and direct measurements. It is surprising to note that of the many works investigated only 3 are in close agreement with both simulation and measurement. Graphical abstract This paper deals with the precise calculation of the electrical capacitance between two conducting spheres of equal, or near equal size.The calculations have been verified by both experimental measurements and simulation. Algorithms in MatLab (Octave) format have been included in the supporting information.}, language = {en} } @article{ChenZhangSongetal., author = {Chen, Rui and Zhang, Zhuo and Song, Ruizhou and Fang, Cheng and Sindersberger, Dirk and Monkman, Gareth J. and Guo, Jianglong}, title = {Time-dependent electroadhesive force degradation}, series = {Smart Materials and Structures}, volume = {29}, journal = {Smart Materials and Structures}, number = {5}, publisher = {IOP Publishing}, doi = {10.1088/1361-665X/ab79b5}, abstract = {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.}, language = {en} } @article{SorokinStepanovShamoninChamonineetal., author = {Sorokin, Vladislav V. and Stepanov, Gennady V. and Shamonin (Chamonine), Mikhail and Monkman, Gareth J. and Kramarenko, Elena Yu}, title = {Magnetorheological behavior of magnetoactive elastomers filled with bimodal iron and magnetite particles}, series = {Smart materials and structures}, volume = {26}, journal = {Smart materials and structures}, number = {3}, publisher = {IOP Publishing}, doi = {10.1088/1361-665X/26/3/035019}, abstract = {Magnetoactive elastomers (MAE) based on soft silicone matrices, filled with various proportions of large diameter ( approximately 50 mu m) iron and small diameter ( approximately 0.5 mu m) magnetite particles are synthesized. Their rheological behavior in homogeneous magnetic fields up to 600 mT is studied in detail. The addition of small magnetite particles facilitates fabrication of uniformly distributed magnetic elastomer composites by preventing aggregation and sedimentation of large particles during curing. It is shown that using the proposed bimodal filler particles it is possible to tailor various magnetorheological (MR) properties which can be useful for different target applications. In particular, either absolute or relative magnetorheological effects can be tuned. The value of the damping factor as well as the range of deformation amplitudes for the linear viscoelastic regime can be chosen. The interdependencies between different MR properties of bimodal MAEs are considered. The results are discussed in the model framework of particle network formation under the simultaneous influence of external magnetic fields and mechanical deformation.}, language = {en} } @misc{ReindlErikssonNiemetzetal., author = {Reindl, Andrea and Eriksson, Lars and Niemetz, Michael and Sangyoung, Park and Meier, Hans}, title = {Control Concepts for a Decentralized Battery Management System Decentralized Battery Management System Global Control Level}, series = {16th International Renewable Energy Storage Conference (IRES2022), 20 to 22 September 2022, D{\"u}sseldorf}, journal = {16th International Renewable Energy Storage Conference (IRES2022), 20 to 22 September 2022, D{\"u}sseldorf}, publisher = {Eurosolar}, language = {en} } @inproceedings{KoernerReindlMeieretal., author = {K{\"o}rner, Patrick and Reindl, Andrea and Meier, Hans and Niemetz, Michael}, title = {A Theoretical Comparison of Different Virtual Synchronous Generator Implementations on Inverters}, series = {2022 24th European Conference on Power Electronics and Applications (EPE'22 ECCE Europe): 05-09 September 2022, Hannover, Germany}, booktitle = {2022 24th European Conference on Power Electronics and Applications (EPE'22 ECCE Europe): 05-09 September 2022, Hannover, Germany}, publisher = {IEEE}, pages = {9}, abstract = {The goal to overcome the global climate crisis leads to a rising demand for the usage of Renewable Energy Sources (RES). Decentralized control strategies are needed to allow the integration of RES into the grid. The Virtual Synchronous Generator (VSG) is proposed as a method to add virtual inertia to the grid by emulating the rotating mass of a Synchronous Generator (SG) on the control algorithm of an inverter. This paper presents the VSG control structure as well as the mathematical description in a unified form. Due to the fact that classical droop control can be seen as a special form of the VSG, their correlation is highlighted by evaluating the steady state output characteristics of the inverter. Furthermore, a theoretical comparison between different VSG topologies, including the VISMA-Method 2 and the synchronverter, is given. In order to achieve better voltage stability, principles to add virtual impedance to the inverter's output are described.}, language = {en} } @inproceedings{ParedesKeimNonnetal., author = {Paredes, Marcelo and Keim, Vincent and Nonn, Aida and Wierzbicki, Tomasz}, title = {Effect of plasticity parameter on the crack propagation in steel pipelines}, 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} } @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} } @article{BringoutErbFrikel, author = {Bringout, Ga{\"e}l and Erb, Wolfgang and Frikel, J{\"u}rgen}, title = {A new 3D model for Magnetic Particle Imaging using realistic magnetic field topologies for algebraic reconstruction}, series = {Inverse Problems}, volume = {36}, journal = {Inverse Problems}, number = {12}, publisher = {IOP Publishing}, doi = {10.1088/1361-6420/abb446}, abstract = {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.}, language = {en} } @misc{Rauch, type = {Master Thesis}, author = {Rauch, Johannes}, title = {Entwicklung eines Regelverfahrens f{\"u}r einen optimierten und zentralen Blindleistungsabruf zur Beeinflussung des Blindleistungshaushalts von Mittelspannungsnetzen unter Einhaltung von Netzrestriktionen}, doi = {10.35096/othr/pub-659}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-6595}, school = {Ostbayerische Technische Hochschule Regensburg}, pages = {115}, abstract = {Die Energiewende f{\"u}hrt zu neuen Herausforderungen f{\"u}r Verteilungsnetzbetreiber hinsichtlich der Er-bringung von Systemdienstleistungen, der Integration weiterer Erzeugungsanlagen und Lasten sowie der Gew{\"a}hrleistung einer hohen Versorgungssicherheit und normgerechten Spannungsqualit{\"a}t. Die De-ckung der auftretenden Blindleistungsbedarfe seitens der Netzbetriebsmittel, Verbraucher und Erzeu-gungsanlagen gewinnt durch den Wegfall der Großkraftwerke f{\"u}r Netzbetreiber zunehmend an Bedeu-tung. Das Projekt SyNErgie besch{\"a}ftigt sich diesbez{\"u}glich mit der Entwicklung neuartiger Blindleis-tungsmanagementsysteme f{\"u}r Mittelspannungsnetze. Ziel ist es, das bisher ungenutzte, freie Blindleis-tungspotential betrieblicher Kompensationsanlagen und dezentraler Erzeugungsanlagen (allgemein: Blindleistungsquellen) zu nutzen, um die Blindleistungs{\"a}nderungsf{\"a}higkeit eines Verteilungsnetzes zu erh{\"o}hen. Diese Arbeit besch{\"a}ftigt sich mit der Entwicklung eines zentralen Blindleistungsregelsystems, bei dem Blindleistungsquellen auf Basis von „Optimal Power Flow"-Berechnungen {\"u}ber eine zentrale Recheninstanz angesteuert werden. Zum Einsatz kommt dabei ein Optimierungsalgorithmus, der auf Basis des aktuellen Netzzustandes (Spannungs- und Auslastungsreserven) und des aktuellen Blindleis-tungspotentials der Blindleistungsquellen einen bedarfsoptimalen Abruf koordiniert. Das zentrale Re-gelverfahren wird in Netzmodellen verschiedenartiger Mittelspannungsnetzgruppen und unterschiedli-cher Art und Anzahl von Blindleistungsquellen angewendet sowie im Hinblick auf variierende Zielvor-gaben und Randbedingungen evaluiert und diskutiert.}, language = {de} } @misc{Urban, type = {Master Thesis}, author = {Urban, Johannes}, title = {Photoelektrisches Direktladen von Elektrofahrzeugen im Inselbetrieb}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-20285}, school = {Ostbayerische Technische Hochschule Regensburg}, pages = {118}, abstract = {Die Arbeit befasst sich mit der Ladung von Elektrofahrzeugen durch Solarenergie in einem Inselsystem. Diese Art der Ladung entlastet die Netze und hat einen sehr hohen Leistungswirkungsgrad. Es wurde ein Prototyp einer Direkt-ladestation gebaut, welche verschiedene Elektrofahrzeuge mit einem neuartigen Verfahren aufladen kann. Sie enth{\"a}lt einen optionalen Pufferakkumulator und einen Vollbr{\"u}cken-Gegentaktwandler f{\"u}r die Ladung bei schlechter Solarleistung. Ein Teil der Arbeit behandelt ausf{\"u}hrlich die Auslegung, die Komponenten und bisher undokumentiertes Verhalten von Gegentaktwandlern. Des Weiteren wird das Prinzip der Solardirekt-ladung und deren Umsetzung sowie die Umsetzung des Gesamtsystems beschrieben. Es folgt ein Kapitel zur Wirtschaftlichkeit der Solardirektladung mit Handlungsempfehlungen. Insgesamt l{\"a}sst sich schließen, dass Solardirektladung bei nutzungsorientierter Auslegung der Anlage und langer Laufzeit wirtschaftlich ist. This work addresses the charging of electric vehicles with solar power in an off-grid system. Charging this way reduces the stress on the grid and has a very high power efficiency. A prototype of a direct charging station was built which is able to charge several different electric vehicles in a novel way. It includes an optional buffer battery and a full bridge converter for being able to charge electric vehicles at times o flow solar power. One chapter explains in detail the design, the components and so far undocumented properties of full and half bridge converters. The principle and the implementation of direct solar charging and the implementation of the whole system is described. The last chapter covers the cost effectiveness of solar chargin gas well as recommendations. All in all it can be stated that solar direct charging is ecomomically advantageous if it is projected according to the user's demand.}, subject = {Fotovoltaik}, 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} } @inproceedings{SchorrBoehmZentneretal., author = {Schorr, Philipp and B{\"o}hm, Valter and Zentner, Lena and Zimmermann, Klaus}, title = {Dynamical Investigation of Crawling Motion System based on a Multistable Tensegrity Structure}, series = {Proceedings of the 15th International Conference on Informatics in Control, Automation and Robotics : Porto, Portugal, 29.07.2018 - 31.07.2018}, booktitle = {Proceedings of the 15th International Conference on Informatics in Control, Automation and Robotics : Porto, Portugal, 29.07.2018 - 31.07.2018}, publisher = {SCITEPRESS}, isbn = {978-989-758-321-6}, doi = {10.5220/0006852701220130}, pages = {122 -- 130}, abstract = {The basic idea of this article is the utilization of the multistable character of a compliant tensegrity structure to control the direction of motion of a crawling motion system. A crawling motion system basing on a two-dimensional tensegrity structure with multiple stable equilibrium states is considered. This system is in contact with a horizontal plane due to gravity. For a selected harmonic actuation of the system small oscillations around the given equilibrium state of the tensegrity structure occur and the corresponding uniaxial motion of the system is evaluated. A change of the equilibrium state of the tensegrity structure yields to novel configuration of the entire system. Moreover, the motion behavior of the novel configuration is totally different although the actuation strategy is not varied. In particular, the direction of motion changes. Therefore, this approach enables a uniaxial bidirectional crawling motion with a controllable direction of motion using only one actuat or with a selected excitation frequency.}, language = {en} } @article{SchorrBoehmZentneretal., author = {Schorr, Philipp and B{\"o}hm, Valter and Zentner, Lena and Zimmermann, Klaus}, title = {Motion characteristics of a vibration driven mobile tensegrity structure with multiple stable equilibrium states}, series = {Journal of Sound and Vibration}, volume = {437}, journal = {Journal of Sound and Vibration}, number = {December}, publisher = {Elsevier}, doi = {10.1016/j.jsv.2018.09.019}, pages = {198 -- 208}, abstract = {A novel type of a vibration driven motion system based on a compliant tensegrity structure with multiple stable equilibrium states is considered. These equilibrium configurations correspond to different prestress states with different dynamical properties. Therefore, the motion characteristics can be varied by changing the equilibrium state. For the application in the fields of mobile robotics, these discrete adjustable dynamics are advantageous. The vibration modes of the structure as well as the corresponding motion characteristics of the system can be adapted to the given environmental conditions in order to ensure a reliable motion. In this paper, dynamical investigations of an exemplary two-dimensional multistable tensegrity structure are considered. For the chosen parameter values the structure features two relevant equilibrium configurations. The resulting motion system is in contact to a horizontal plane due to gravity and the actuation is realized by the harmonic variation of the length of a single tensioned member. The motion of the system is simulated for various actuation frequencies with the different equilibrium states as an initial configuration. A uniaxial or a planar movement occurs depending on the selection of the actuated member within the tensegrity structure. The steady state motion is evaluated regarding motion characteristics like the steady state velocity. Moreover, the influences on the motion behavior caused by the different equilibrium states as an initial condition are emphasized. (C) 2018 Elsevier Ltd. All rights reserved.}, language = {en} } @inproceedings{BoehmSchorrZimmermannetal., author = {B{\"o}hm, Valter and Schorr, Philipp and Zimmermann, Klaus and Zentner, Lena}, title = {An Approach to the Estimation of the Actuation Parameters for Mobile Tensegrity Robots with Tilting Movement Sequences}, series = {2018 International Conference on Reconfigurable Mechanisms and Robots (ReMAR); 20-22 June 2018; Delft, Netherlands}, booktitle = {2018 International Conference on Reconfigurable Mechanisms and Robots (ReMAR); 20-22 June 2018; Delft, Netherlands}, publisher = {IEEE}, doi = {10.1109/REMAR.2018.8449871}, pages = {1 -- 8}, abstract = {This paper deals with the locomotion by tilting sequences of shape-variable compliant tensegrity structures. The shape of these structures is controlled by manipulating their prestress state. The tensegrity structure is tilting as consequence of a suitable variation of its shape. By multiple repetition of such tilting sequences a motion is generated. Quasi-static considerations for the considered structures are presented in order to estimate the actuation parameters. For a proper number of actuators this quasi-static approach enables an analytical calculation of the actuation parameters of the structure in order to control the geometrical configuration as required. As an example a two-dimensional tensegrity structure which is in contact with a horizontal plane due to gravity is considered. By successive tilting sequences a uniaxial motion results. The excitation of the structure is calculated for a given change of shape with the quasi-static analysis. The according results are compared with transient dynamic simulations. Qualitative conclusions about the motion behavior and the usability of the quasi-static approach are given.}, language = {en} } @inproceedings{CarrilloLiSchorrKaufholdetal., author = {Carrillo Li, Enrique Roberto and Schorr, Philipp and Kaufhold, Tobias and Rodr{\´i}guez Hern{\´a}ndez, Jorge Antonio and Zentner, Lena and Zimmermann, Klaus and B{\"o}hm, Valter}, title = {Kinematic analysis of the rolling locomotion of mobile robots based on tensegrity structures with spatially curved compressed components}, series = {Applicable Solutions in Non-Linear Dynamical Systems; 15th International Conference "Dynamical Systems - Theory and Applications" (DSTA 2019, 2-5 December, 2019, Lodz, Poland}, booktitle = {Applicable Solutions in Non-Linear Dynamical Systems; 15th International Conference "Dynamical Systems - Theory and Applications" (DSTA 2019, 2-5 December, 2019, Lodz, Poland}, editor = {Awrejcewicz, Jan and Ka{\'{z}}mierczak, Markek and Olejnik, Paweł}, publisher = {Wydawnictwo Politechniki Ł{\´o}dzkiej}, address = {Ł{\´o}d{\'{z}}, Polen}, isbn = {978-83-66287-30-3}, pages = {335 -- 344}, abstract = {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.}, language = {en} } @inproceedings{NonnParedesKeimetal., author = {Nonn, Aida and Paredes, Marcelo and Keim, Vincent and Wierzbicki, Tomasz}, title = {Comparison of Fracture Models to Quantify the Effects of Material Plasticity on the Ductile Fracture Propagation in Pipelines}, series = {Proceedings of the 2018 12th International Pipeline Conference, Volume 3: Operations, Monitoring, and Maintenance, Materials and Joining, September 24-28, 2018, Calgary, Alberta, Canada}, booktitle = {Proceedings of the 2018 12th International Pipeline Conference, Volume 3: Operations, Monitoring, and Maintenance, Materials and Joining, September 24-28, 2018, Calgary, Alberta, Canada}, doi = {10.1115/IPC2018-78366}, abstract = {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.}, language = {en} } @article{KeimParedesNonnetal., author = {Keim, Vincent and Paredes, Marcelo and Nonn, Aida and M{\"u}nstermann, Sebastian}, title = {FSI-simulation of ductile fracture propagation and arrest in pipelines}, series = {International Journal of Pressure Vessels and Piping}, volume = {182}, journal = {International Journal of Pressure Vessels and Piping}, number = {May}, publisher = {Elsevier}, doi = {10.1016/j.ijpvp.2020.104067}, abstract = {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.}, subject = {Bruchmechanik}, 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} } @inproceedings{SteiningerGadererDawoud, author = {Steininger, Peter and Gaderer, Matthias and Dawoud, Belal}, title = {Transient performance of a solar selective thermal insulation system}, series = {16th Advanced Building Skins Conference \& Expo, 21 - 22/10/2021, Bern, Switzerland}, booktitle = {16th Advanced Building Skins Conference \& Expo, 21 - 22/10/2021, Bern, Switzerland}, publisher = {Advanced Buidling Skins GmbH}, abstract = {A prototype of a thermal insulation system to offer high selectivity of the solar gain regarding the solar incidence angle (SATIS) was applied to a typical solid brick masonry for existing buildings in Germany. Light conducting elements (LCEs) inclined at 19 ° were incorporated in SATIS, which equals the average solar noon angle in southern Germany during winter. The entire wall construction was experimentally investigated in a differential climatic chamber test bench at four different irradiation angles according to a dynamic test procedure. In addition, a conventional wall construction (CWC) has been measured. At SATIS' design angle of 19 °, the SATIS wall construction shows a solar gain (SG) of 394.5 Wh/m², while the SG of the CWC amounts to only 25.4 Wh/m². The validated transient model of the SATIS wall construction showed that, at the end of the irradiation period of the dynamic test procedure (8 h), the solar heat penetrates to a depth of 253 mm and 111 mm inside the 385 mm thick brick wall masonry at the irradiation angles of 19 ° and 50 °, respectively. During the same time, the stored solar energy at 50 ° amounts to only 24.4 \% of that stored at 19 °.}, language = {en} } @article{SchaechingerBruecklBeckeretal., author = {Sch{\"a}chinger, J. and Br{\"u}ckl, Oliver and Becker, Mark and Lechner, Raphael}, title = {Results of the Research Project Optibiosy: Biogas plants as stabilizers of the power system?}, series = {BWK ENERGIE}, volume = {74}, journal = {BWK ENERGIE}, number = {11-12}, publisher = {VDI-Verlag}, address = {D{\"u}sseldorf}, issn = {1436-4883}, pages = {34 -- 39}, language = {en} } @techreport{KlitsmanStaudacherBrueckletal., author = {Klitsman, Maksym and Staudacher, Lars and Br{\"u}ckl, Oliver and Eller, Johannes and Brey, Ludwig and Eigenstetter, Florian}, title = {neos - NetzEntwicklungsOffensive Strom - Schlussbericht}, doi = {10.35096/othr/pub-4524}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-45248}, pages = {143}, abstract = {Im Zuge der Energiewende werden die erneuerbaren Energien zur tragenden S{\"a}ule unserer Stromversorgung. Bis 2025 sollen bundesweit 40-45 \% des Stroms aus erneuerbaren Quellen stammen, bis 2050 sogar 80 \%. Dabei wird der erzeugte Strom haupts{\"a}chlich aus Wind und Sonne stammen. Im Norden der Bundesrepublik wird Wind die Erzeugung dominieren, w{\"a}hrend im S{\"u}den, insbesondere in Bayern der Strom vornehmlich aus Photovoltaik gewonnen werden wird. Um die Ziele der Energiewende zu erreichen, wird neben den ausreichenden Erzeugungskapazit{\"a}ten auch eine leistungsf{\"a}hige Infrastruktur zur Verteilung und Nutzung des erneuerbaren Stroms notwendig sein. Planbarkeit und Sicherung der Versorgungsqualit{\"a}t bei zunehmenden Anteilen von volatiler Erzeugung werden dabei zu einer immer gr{\"o}ßeren Herausforderung. Das Projekt neos hat im engen Verbund mit den beteiligten Partnern wichtige tagesaktuelle Fragestellungen wissenschaftlich er{\"o}rtert und untersucht, die sich durch die laufende Transformation des Energiesystems und den rasanten Ausbau der Anlagen zur erneuerbaren Energieerzeugung den Projektpartnern stellen.}, subject = {Intelligentes Stromnetz}, language = {de} } @inproceedings{HaumerKral, author = {Haumer, Anton and Kral, Christian}, title = {The New EDrives Library: A Modular Tool for Engineering of Electric Drives}, series = {Proceedings of the 10th International Modelica Conference, March 10-12, 2014, Lund, Sweden}, booktitle = {Proceedings of the 10th International Modelica Conference, March 10-12, 2014, Lund, Sweden}, publisher = {Link{\"o}ping University Electronic Press}, isbn = {978-91-7519-380-9}, issn = {1650-3686}, doi = {10.3384/ecp14096155}, pages = {155 -- 163}, abstract = {Simulation is an indispensable tool for the engineering of systems containing electric drives. Depending on the design phase and the engineering task different levels of modeling details are required: proof of concept; investigation of energy and power consumption; design of control; etc. The new EDrives library provides three levels of abstraction for inverters: quasi static (neglecting electrical transients); averaging (neglecting switching effects) and switching - for serving different demands. The inverters can feed the machine models of the Modelica Standard Library: Modelica.Magnetic.FundamentalWave and the new Modelica.Magnetic.QuasiStatic.FundamentalWave. The EDrives library copes with arbitrary phase numbers and can be easily extended to develop new control algorithms. In this publication the structure of the library and the implemented control principles are presented. Furthermore; examples comparing the three different levels of abstraction are included.}, language = {en} } @article{GraggerHaumerEinhorn, author = {Gragger, Johannes V. and Haumer, Anton and Einhorn, Markus}, title = {Averaged Model of a Buck Converter for Efficiency Analysis}, series = {Engineering Letters}, volume = {18}, journal = {Engineering Letters}, address = {Hong Kong}, abstract = {In this work a buck converter model for multidomain simulations is proposed and compared with a state-of-the-art buck converter model. In the proposed model no switching events are calculated. By avoiding the computation of the switching events in power electronic models the processing time of multidomain simulations can be decreased significantly. The proposed model calculates any operation point of the buck converter in continuous inductor current conduction mode (CICM) while considering the conduction losses and switching losses. It is possible to utilize the proposed modeling approach also for other dc-to-dc converter topologies. Laboratory test results for the validation of the proposed model are included.}, language = {en} } @misc{Heberl, type = {Master Thesis}, author = {Heberl, Michael}, title = {Power-to-Ammoniak}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-22167}, school = {Ostbayerische Technische Hochschule Regensburg}, pages = {68}, abstract = {Ammoniak ist Grundbaustein f{\"u}r die Herstellung von D{\"u}ngemitteln und dementsprechend f{\"u}r die Nahrungsmittelindustrie unentbehrlich. Ca. 40-50 \% der Weltbev{\"o}lkerung sind von Nahrungsmitteln abh{\"a}ngig, die mit Hilfe von Ammoniakd{\"u}ngern hergestellten wurden. Weltweit wurden alleine im Jahr 2015 181 Mt Ammoniak produziert, wodurch die Ammoniakherstellung mit 1,2 \% am gesamten Energieverbrauch der Welt beteiligt ist und f{\"u}r 0,93 \% der globalen Treibhausgasemissionen zust{\"a}ndig ist. Auch in Zeiten der Energiewende ist diese Grundstoffchemikalie unentbehrlich, ist aber auf einem anderen Wege herzustellen. Ziel dieser Arbeit ist die Darstellung verschiedener M{\"o}glichkeiten zur erneuerbaren Elektrifizierung und Dekarbonisierung der Ammoniakindustrie, wodurch der Einsatz von herk{\"o}mmlichen Energietr{\"a}gern wie Erdgas, Kohle und {\"O}l negiert werden kann. Ammoniak wird aktuell {\"u}ber das Haber-Bosch-Verfahren aus den Rohstoffen Erdgas, Kohle und {\"O}l gewonnen. Bei diesem Verfahren wird {\"u}ber einen Prim{\"a}r- und Sekund{\"a}rreformer Wasserstoff und Stickstoff gewonnen. Andere Gasbestandteile werden gefiltert oder umgewandelt, um sch{\"a}dliche Katalysatorgifte (CO, H2S) zu entfernen. Im Reaktor wird an Eisenkatalysatoren aus Wasserstoff und Stickstoff letztendlich Ammoniak hergestellt. Der Energieverbrauch des Haber-Bosch Verfahrens schwankt zwischen 7,8 MWh/t NH3 f{\"u}r eine moderne und sehr effiziente Anlage mit Erdgas und 13,6 MWh/t NH3 f{\"u}r eine alte mit Kohle betriebene Anlage. An Emissionen treten pro hergestellter Tonne Ammoniak je nach Rohstoff 1,6-3,8 t CO2-eq auf. Neben der Biomassevergasung gibt es mehrere rein elektrische Ans{\"a}tze zur Ammoniakherstellung. Die unterschiedlichen elektrochemischen Ans{\"a}tze zur direkten Ammoniaksynthese, wie der Einsatz von Fl{\"u}ssigsalzelektrolyten oder Feststoffelektrolyten, wurden in Abschnitt 3.2 vorgestellt. Einige dieser Technologien zeigen vielversprechende Ans{\"a}tze, sind jedoch zum aktuellen Zeitpunkt noch zu weit von einem industriellen Einsatz entfernt. Der Einsatz der Wasserelektrolyse in Kombination mit einer Luftzerlegungseinheit ist die derzeit vielversprechendste Methode Ammoniak auf einem strombasierten und dekarbonisierten Wege herzustellen. Bei diesem System wird Wasserstoff im Elektrolyseur und Stickstoff in der Luftzerlegungseinheit hergestellt. Die Ammoniaksynthese findet hierbei in einem Reaktor nach Vorbild des Haber-Bosch-Prozesses statt. Mit diesem System ist ein Energieverbrauch von ca. 10 MWh/t NH3 notwendig. Durch den Einsatz von rein erneuerbar hergestelltem Strom als Energietr{\"a}ger l{\"a}sst sich mit diesem Technologiezusammenschluss die Ammoniakherstellung komplett Emissionsfrei gestalten. Dadurch k{\"o}nnen alleine in Deutschland j{\"a}hrlich bis zu 7,8 Mt CO2-eq eingespart werden. Eine zuk{\"u}nftige Umstrukturierung der Ammoniakherstellung und der gesamten chemischen Industrie ist unabdingbar. Diese kann aber nur parallel mit einem Ausbau erneuerbarer Energien umgesetzt werden. Mit der Wasserelektrolyse und der Luftzerlegungseinheit sind die technischen M{\"o}glichkeiten f{\"u}r diesen Umbau bereits heute gegeben und brauchen nur noch eingesetzt werden.}, language = {de} } @article{GaertnerMarxSchubachGadereretal., author = {G{\"a}rtner, Sebastian and Marx-Schubach, Thomas and Gaderer, Matthias and Schmitz, Gerhard and Sterner, Michael}, title = {Techno-Economic Analysis of Carbon Dioxide Separation for an Innovative Energy Concept towards Low-Emission Glass Melting}, series = {energies}, volume = {16}, journal = {energies}, number = {5}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/en16052140}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-53627}, pages = {1 -- 25}, abstract = {The currently still high fossil energy demand is forcing the glass industry to search for innovative approaches for the reduction in CO2 emissions and the integration of renewable energy sources. In this paper, a novel power-to-methane concept is presented and discussed for this purpose. A special focus is on methods for the required CO2 capture from typical flue gases in the glass industry, which have hardly been explored to date. To close this research gap, process simulation models are developed to investigate post-combustion CO2 capture by absorption processes, followed by a techno-economic evaluation. Due to reduced flue gas volume, the designed CO2 capture plant is found to be much smaller (40 m3 absorber column volume) than absorption-based CO2 separation processes for power plants (12,560 m3 absorber column volume). As there are many options for waste heat utilization in the glass industry, the waste heat required for CO2 desorption can be generated in a particularly efficient and cost-effective way. The resulting CO2 separation costs range between 41 and 42 EUR/t CO2, depending on waste heat utilization for desorption. These costs are below the values of 50-65 EUR/t CO2 for comparable industrial applications. Despite these promising economic results, there are still some technical restrictions in terms of solvent degradation due to the high oxygen content in flue gas compositions. The results of this study point towards parametric studies for approaching these issues, such as the use of secondary and tertiary amines as solvents, or the optimization of operating conditions such as stripper pressure for further cost reductions potential.}, language = {en} } @article{FreniFrazzicaDawoudetal., author = {Freni, Angelo and Frazzica, Andrea and Dawoud, Belal and Chmielewski, Stefanie and Calabrese, Luigi and Bonaccorsi, Lucio Maria}, title = {Adsorbent coatings for heat pumping applications: Verification of hydrothermal and mechanical stabilities}, series = {Applied Thermal Engineering}, volume = {50}, journal = {Applied Thermal Engineering}, number = {2}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2011.07.010}, pages = {1658 -- 1663}, abstract = {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.}, language = {en} } @article{Dawoud, author = {Dawoud, Belal}, title = {Water vapor adsorption kinetics on small and full scale zeolite coated adsorbers; A comparison}, series = {Applied thermal engineering}, volume = {50}, journal = {Applied thermal engineering}, number = {2}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2011.07.013}, pages = {1645 -- 1651}, abstract = {A possibility to enhance both heat and mass transfer characteristics of an adsorber heat exchanger is to apply the adsorbent directly to its surface in form of a consolidated layer. As the majority of the available publications on the effect of both coating technology and adsorbent layer thickness on the adsorption kinetics deals with small scale adsorbent samples, the results obtained can only represent the best case design of an adsorber heat exchanger. This article presents, therefore, a comparison between the adsorption kinetics of water vapour on small as well as two different full scale coated adsorber heat exchanger types with AQSOA-Z02 layers of Mitsubishi Plastics Incorporation under quasi isobaric conditions of adsorption heat pumps. The small scale coated samples have a zeolite dry mass of 200 mg and layer thicknesses of 200, 300 and 500 μm while the full scale adsorbers have a coated zeolite mass between 1.5 and 2.5 kg and layer thicknesses of 150, 200, 300, 400 and 500 μm. In the investigated adsorption heat pump module, up to 52.7 and 57.3\% of the equilibrium differential water loading measured with the small scale coated substrates have been obtained after an adsorption-evaporation times of 300 and 600 s, respectively.}, language = {en} } @techreport{SternerBauerHofrichteretal., author = {Sterner, Michael and Bauer, Franz and Hofrichter, Andreas and Heberl, Michael}, title = {Systemanalyse und -integration Power-to-X im Kontext von erneuerbarer Elektrizit{\"a}t als Prim{\"a}renergie (SPIKE)}, pages = {87}, abstract = {Durch das in Paris beschlossene Ziel, die globale mittlere Temperatur auf deutlich unter 2 Grad Celsius gegen{\"u}ber dem vorindustriellen Niveau zu begrenzen, ist ein Ausstieg aus der Nutzung fossiler Energietr{\"a}ger und Rohstoffe bis zum Jahr 2050 notwendig (WBGU 2016). Daher hat sich die Bundesregierung das Ziel gesetzt, bis zur Mitte des Jahrhunderts eine weitgehende Treibhausgasneutralit{\"a}t zu erreichen. Hierzu ist neben einer Steigerung der Energieeffizienz in allen Sektoren ein Ausbau erneuerbaren Energien notwendig. Dies beinhaltet haupts{\"a}chlich den Zubau von Wind- und Solarstromanlagen. Somit gewinnt die Sektorkopplung immer mehr an Bedeutung und wird in Zukunft eine tragende Rolle f{\"u}r die Defossilisierung des Energiesystems spielen (BMUB 2016). Als zentrales Element der Sektorkopplung gilt Strom, der {\"u}ber Power-to-X (PtX) sowohl energetisch im W{\"a}rme-, und Verkehrssektor als auch stofflich in der Industrie und vor allem im Chemiesektor eingesetzt werden kann (Ausfelder et al. 2018a). Im Rahmen des P2X-Vorhabens der Kopernikus Forschungsinitiative wird die Sektorkopplung durch die Umwandlung von Strom mittels elektrochemischer Prozesse in stoffliche Ressourcen wie Wasserstoff, Synthesegas oder Kohlenstoffmonoxid untersucht. Der Schwerpunkt liegt auf der Betrachtung der Kopplung von Strom und Verkehr sowie Strom und Chemie und der Untersuchung von Prozessen und Pfaden, die aus {\"o}kologischer, {\"o}konomischer und gesellschaftlicher Sicht vorteilhaft sind. Eine vergleichende Einordnung in den Gesamtkontext der Energiewende mit Abw{\"a}gung zahlreicher Alternativen und Konkurrenztechnologien ist dort allerdings nicht vorgesehen. Zudem werden einige relevante PtX-Technologien wie Power-to-Heat nicht betrachtet. Aus diesem Grund wurden in SPIKE erg{\"a}nzende PtX-Technologiepfade aus systemanalytischer Sicht untersucht. Dies sind Power-to-Heat (PtH) und Power-to-Gas (PtG) {\"u}ber Elektrolyse und optionaler anschließender Methanisierung sowie die Herstellung ausgew{\"a}hlter Pfade der strombasierten Herstellung von Produkten der energieintensiven Industrie. Ziel des Forschungsvorhabens war die Analyse von PtX-Technologien und Pfaden, deren vergleichende Einordnung im Gesamtkontext der Energiewende sowie die Unterst{\"u}tzung des P2X Roadmapping Prozesses und die Ableitung von Handlungsempfehlungen. Ein besonderer Schwerpunkt lag auf dem Einsatz von PtX im Industriesektor. F{\"u}r das Vorhaben wurden Arbeitspakete (AP) erstellt, die Untersuchungen zu Technologie, Potenzial, {\"O}konomie und {\"O}kologie von PtH (AP 1), PtG (AP 2), Power-to-Ammoniak, Power-to-Ethen und Power-to-Propen (AP 3) umfassten. Daraus wurde in AP 4 ein Systemvergleich mit Einordnung von PtX in die Energiewende durchgef{\"u}hrt. Auf dieser Basis und der Identifizierung regulatorischer Rahmenbedingungen f{\"u}r PtX (AP 5) wurde das deutsche Energiesystem samt PtX-Pfaden in einem Energiesystemmodell abgebildet (AP 6). Die Ergebnisse flossen in das Roadmapping ein (AP 7). Zudem erfolgte ein Austausch mit den Projektpartnern und das Verfassen wissenschaftlicher Abhandlungen (AP 8).}, language = {de} } @techreport{ThemaKaulSterneretal., author = {Thema, Martin and Kaul, Anja and Sterner, Michael and Heberl, Michael}, title = {Optimierung eines Rieselbett-Bioreaktors f{\"u}r die dynamische mikrobielle Biosynthese von Methan mit Archaeen-Mikroorganismen in Power-to-Gas-Anlagen}, doi = {10.2314/KXP:1815321555}, abstract = {Das {\"u}bergeordnete Ziel des Vorhabens war die Entwicklung neuer technologischer M{\"o}glichkeiten f{\"u}r den biologischen Methanisierungsprozess mit Archaeen1 in Power-to-Gas-Anwendungen. Im Gegensatz zur technisch ausgereiften chemisch-katalytischen Methanisierung sind hier noch Potenziale zur Optimierung verfahrenstechnischer und biologischer Prozesse f{\"u}r das Speicherkonzept Power-to-Gas [7] vorhanden. Dabei sollte zum einen ein Rieselbett-Bioreaktor optimiert, simuliert und f{\"u}r die Hochskalierung vorbereitet werden. Zum anderen sollte eine Kombination optimal geeigneter Mikroorganismen und Packungsmaterialien selektiert und deren Verhalten und Eignung im Reaktor analysiert werden. Das Verhalten des entwickelten Systems sollte zun{\"a}chst im Labor- und Technikumsmaßstab und anschließend im Feldtest an einer bestehenden Power-to-Gas-Anlage untersucht werden. Hauptziel w{\"a}hrend des Feldtests war die Produktion von einspeisef{\"a}higem Methan sowie dessen Einspeisung ins Gasnetz. Ein Hauptziel des Projektes war es, die Normung und Standardisierung notwendiger Systemparameter und Semantik zur Beschreibung und Einbindung biologischer Methanisierungseinheiten in Power-to-Gas-Anlagen voranzutreiben. Dies sollte zum einen die Vergleichbarkeit der wissenschaftlichen Erkenntnisse verbessern und zum anderen unterst{\"u}tzend bei der Kommerzialisierung der Technologie wirken. Aus dem Projekt heraus wurde so die neue Normungsreihe VDI 4635 Power-to-X beim Verein Deutscher Ingenieure angestoßen.}, language = {de} } @inproceedings{KlitsmanBruecklEller, author = {Klitsman, Maksym and Br{\"u}ckl, Oliver and Eller, Johannes}, title = {Analysis and simulation of the population driving behaviour and charging processes at different charging station types with electric vehicles}, series = {NEIS 2021, Conference on Sustainable Energy Supply and Energy Storage Systems: 13-14. September 2021, Hamburg}, booktitle = {NEIS 2021, Conference on Sustainable Energy Supply and Energy Storage Systems: 13-14. September 2021, Hamburg}, editor = {Schulz, Detlef}, publisher = {VDE-Verlag}, isbn = {978-3-8007-5651-3}, pages = {254 -- 260}, abstract = {Electric vehicles are one of the important components of the energy transition, which is necessary for the CO2 emission reduction. In order to estimate the influence of electromobility on electric grids at present day and in the future, the generation of realistic charge profiles is necessary. The main objective of this study is the development of an algorithm, which generates realistic charge time series of electric vehicles. The very huge and detailed input surveys enable to define different population groups, representing specific driving behaviour. These groups are then composed and scaled up, according to the statistical population structure of a chosen town or city in Germany, and show typical driving behaviour of all inhabitants. The charge profiles are calculated for several charge station types, based on daily electric vehicle user mobility, day type and household type. In addition, charge process occurrence is evaluated through a model, involving charge infrastructure presence, attractiveness of corresponding charge station type and charge process necessity.}, language = {en} } @article{SavelievFetisovChashinetal., author = {Saveliev, Dmitry V. and Fetisov, Leonid Y. and Chashin, Dmitri V. and Shabin, P. A. and Vyunik, D. A. and Fedulov, Feodor and Kettl, W. and Shamonin (Chamonine), Mikhail}, title = {Method of Measuring Deformations of Magnetoactive Elastomers under the Action of Magnetic Fields}, series = {Russian Technological Journal}, volume = {7}, journal = {Russian Technological Journal}, number = {4}, doi = {10.32362/2500-316x-2019-7-4-81-91}, pages = {81 -- 91}, language = {ru} } @article{GamischHuberGadereretal., author = {Gamisch, Bernd and Huber, Lea and Gaderer, Matthias and Dawoud, Belal}, title = {On the Kinetic Mechanisms of the Reduction and Oxidation Reactions of Iron Oxide/Iron Pellets for a Hydrogen Storage Process}, series = {Energies}, volume = {15}, journal = {Energies}, number = {21}, publisher = {MDPI}, doi = {10.3390/en15218322}, abstract = {This work aims at investigating the kinetic mechanisms of the reduction/oxidation (redox) reactions of iron oxide/iron pellets under different operating conditions. The reaction principle is the basis of a thermochemical hydrogen storage system. To simulate the charging phase, a single pellet consisting of iron oxide (90\% Fe2O3, 10\% stabilising cement) is reduced with different hydrogen (H2) concentrations at temperatures between 600 and 800 °C. The discharge phase is initiated by the oxidation of the previously reduced pellet by water vapour (H2O) at different concentrations in the same temperature range. In both reactions, nitrogen (N2) is used as a carrier gas. The redox reactions have been experimentally measured in a thermogravimetric analyser (TGA) at a flow rate of 250 mL/min. An extensive literature review has been conducted on the existing reactions' kinetic mechanisms along with their applicability to describe the obtained results. It turned out that the measured kinetic results can be excellently described with the so-called shrinking core model. Using the geometrical contracting sphere reaction mechanism model, the concentration- and temperature-dependent reduction and oxidation rates can be reproduced with a maximum deviation of less than 5\%. In contrast to the reduction process, the temperature has a smaller effect on the oxidation reaction kinetics, which is attributed to 71\% less activation energy (Ea,Re=56.9 kJ/mol versus Ea,Ox=16.0 kJ/mol). The concentration of the reacting gas showed, however, an opposite trend: namely, to have an almost twofold impact on the oxidation reaction rate constant compared to the reduction rate constant.}, language = {en} } @inproceedings{GaertnerRankHeberletal., author = {G{\"a}rtner, Sebastian and Rank, Daniel and Heberl, Michael and Gaderer, Matthias and Sterner, Michael}, title = {Integration of Power-To-Methane into Glass Melting Processes}, series = {Proceedings of the International Renewable Energy Storage Conference (IRES 2022)}, volume = {16}, booktitle = {Proceedings of the International Renewable Energy Storage Conference (IRES 2022)}, publisher = {Atlantis Press}, issn = {2589-4943}, doi = {10.2991/978-94-6463-156-2_12}, pages = {147 -- 161}, abstract = {The glass industry is facing increased challenges regarding climate protection targets and rising energy costs. The integration of renewable energy including conversion and storage is a key for both challenges in this energy-intensive industrial sector, which has been mainly relying on fossil gas so far. The options considered to this point for reducing CO2 emissions and switching to a renewable energy supply involve far-reaching changes of the established melting processes. This entails significant risks in terms of influences on glass quality and stable production volumes. The presented approach for the integration of a Power-to-Methane (PtM) system into the glass industry is a completely new concept and has not been considered in detail before. It allows the use of established oxyfuel melting processes, the integration of fluctuating renewable energy sources and a simultaneous reduction of CO2 emissions by more than 78\%. At the same time, natural gas purchases become obsolete. A techno-economic evaluation of the complete PtM process shows, that 1,76 €/m3 or 1,26 €/kg synthetic natural gas are possible with renewable energy supply. Using electricity from the energy grid would require electricity prices < 0,126 €/kWh to allow cost competitive PtM processes in the glass industry. Such electricity prices could be achieved by electricity market-based optimization and operation of the PtM system. This operation strategy would require AI-based algorithms predicting availabilities and prices on future-based markets.}, language = {en} } @article{KralHaumerGrabner, author = {Kral, Christian and Haumer, Anton and Grabner, Christian}, title = {Consistent Induction Motor Parameters for the Calculation of Partial Load Efficiencies by Means of an Advanced Simulation Model}, series = {Engineering Letters}, volume = {18}, journal = {Engineering Letters}, number = {1}, address = {Hong Kong}, issn = {1816-0948}, abstract = {From the rating plate data of an induction motor the nominal efficiency can be determined. Without detailed knowledge of equivalent circuit parameters, partial load behavior cannot be computed. Therefore, a combined calculation and estimation scheme is presented, where the consistent parameters of an equivalent circuit are elaborated, exactly matching the nominal operating point. From these parameters part load efficiencies can be determined.}, language = {en} } @article{KlenkGalka, author = {Klenk, Eva Marianne and Galka, Stefan}, title = {Analysis of real-time tour building and scheduling strategies for in-plant milk-run systems with volatile transportation demand}, series = {IFAC - PapersOnLine}, volume = {52}, journal = {IFAC - PapersOnLine}, number = {13}, publisher = {Elsevier}, doi = {10.1016/j.ifacol.2019.11.517}, pages = {2110 -- 2115}, abstract = {In modern manufacturing systems, milk run (MR) systems represent route-based, cyclic material-handling systems that are used widely and enable frequent deliveries of containerized parts in small lot sizes from a central storage area to multiple points of use on the factory floor. Usually, deliveries take place at predetermined, constant time intervals. As in real-world MR systems, the number of containers to deliver in each interval varies in the short term, peaks in the number of deliveries may lead to capacity bottlenecks and late deliveries. In this paper, we develop three alternative strategies to determine starting times of MR cycles in real-time based on the current number of delivery orders in the system aiming to better handle variations in the number of orders. We evaluate the three strategies for different system load scenarios with respect to delivery service levels, order lead times, systems utilization and necessary number of MR trains using a discrete-event simulation model.}, language = {en} } @misc{PershinaSavelievGlavanetal., author = {Pershina, K. V. and Saveliev, Dmitry V. and Glavan, Gašper and Chashin, Dmitri V. and Belyaeva, Inna A. and Fetisov, Leonid Y. and Shamonin (Chamonine), Mikhail}, title = {The voltage response of a structure comprising a magnetoactive-elastomer cylinder and a piezoelectric material to magnetic field step excitations}, series = {The 4th International Baltic Conference on Magnetism (IBCM 2021) : Svetlogorsk, Russia August 29 - September 2, 2021 : Book of Abstracts}, journal = {The 4th International Baltic Conference on Magnetism (IBCM 2021) : Svetlogorsk, Russia August 29 - September 2, 2021 : Book of Abstracts}, publisher = {Immanuel Kant Baltic Federal University, Kaliningrad, Russia}, pages = {182}, language = {en} } @techreport{RankHeberlSterner, author = {Rank, Daniel and Heberl, Michael and Sterner, Michael}, title = {Die CO2-Bilanz der OTH [Ostbayerischen Technische Hochschule Regenburg]}, language = {de} } @misc{SternerHeberl, author = {Sterner, Michael and Heberl, Michael}, title = {The ORBIT-Project: Biological methanation in a trickle-bed reactor - key results and next steps}, series = {5th Nuremberg Workshop on Methanation and 2nd Generation, N{\"u}rnberg Friedrich-Alexander-Universit{\"a}t, 28.05.2021}, journal = {5th Nuremberg Workshop on Methanation and 2nd Generation, N{\"u}rnberg Friedrich-Alexander-Universit{\"a}t, 28.05.2021}, organization = {Friedrich-Alexander-Universit{\"a}t Erlangen-N{\"u}rnberg / Lehrstuhl f{\"u}r Energieverfahrenstechnik}, language = {en} } @misc{AltmannGebhard, author = {Altmann, Robert and Gebhard, J{\"u}rgen}, title = {Ph{\"a}nomenologische Untersuchung des Einspritzprozesses eines Injektors aus dem Off-Highway-Segment mit Diesel- und Raps{\"o}lkraftstoff}, series = {16. Internationaler Fachkongress "Kraftstoffe der Zukunft 2019", Berlin}, journal = {16. Internationaler Fachkongress "Kraftstoffe der Zukunft 2019", Berlin}, language = {de} } @incollection{GrabnerGraggerKapelleretal., author = {Grabner, Christian and Gragger, Johannes V. and Kapeller, Hansj{\"o}rg and Haumer, Anton and Kral, Christian}, title = {Sensorless PM-Drive Aspects}, series = {Electronic Engineering and Computing Technology}, booktitle = {Electronic Engineering and Computing Technology}, editor = {Ao, Sio-Iong and Gelman, Len}, publisher = {Springer}, address = {Dordrecht}, isbn = {978-90-481-8775-1}, doi = {10.1007/978-90-481-8776-8_3}, pages = {25 -- 35}, abstract = {The development procedure of permanent magnet drives for sensor less operation beginning from standstill under overload conditions has to consider different design aspects coevally. First, the robust rotor position sensing by test signal enforces a design with a strongly different behavior of the spatial dq-oriented differential inductance values. Therefore, the interior rotor magnet array arrangement is from principle predestinated for the controlled sensor less mode including standstill. Fortunately, in order to reduce costs, the distinct reluctance torque capability of such interior magnet arrangement is additionally used for a significantly increased torque by applying a pre-oriented stator current space vectors within the quasi-steady control.}, language = {en} } @article{GamischEttengruberGadereretal., author = {Gamisch, Bernd and Ettengruber, Stefan and Gaderer, Matthias and Dawoud, Belal}, title = {Dynamic simulation of isothermal and non-isothermal reduction and oxidation reactions of iron oxide for a hydrogen storage process}, series = {Renewable and Sustainable Energy}, volume = {1}, journal = {Renewable and Sustainable Energy}, number = {1}, publisher = {ELSP, International Open Science Platform}, doi = {10.55092/rse20230004}, abstract = {This work aims first to develop a dynamic lumped model for the isothermal reactions of hydrogen/steam with a single iron oxide/iron pellet inside a tubular reactor and to validate the model results against the experimental reaction kinetic data with the help of our STA device. To describe the temporal change in mass, and consequently, the temporal heat of reaction, the shrinking core model, based on the geometrical contracting sphere, is applied. It turned out that, the simulation model can reproduce the experimental, temporal concentration and temperature-dependent conversion rates with a maximum deviation of 4.6\% during the oxidation reactions and 3.1\% during the reduction reactions. In addition, a measured isothermal storage process comprising one reduction and one oxidation phase with a holding phase in between on a single reacting pellet could be reproduced with a maximum absolute deviation in the conversion rate of 1.5\%. Moreover, a lumped, non-isothermal simulation model for a pelletized tubular redox-reactor including 2kg of iron oxide pellets has been established, in which the heat of reaction, heat transfer to the ambient and heat transfer between the solid and gas phases are considered. The temporal courses of the outlet gas concentration as well as the temperatures of the gas stream and the solid material at a constant input gas flow rate and a constant reacting gas inlet concentration but different input gas temperatures are estimated. Because of the endothermic nature of the reduction reaction, the inlet reacting gas temperature shall be kept high to prevent the severe temperature drop in the solid phase and, consequently, the significant reduction of the reaction rate. Contrary to that, the oxidation process requires lower input gas temperatures to avoid the excessive overheating of the reaction mass and, consequently, the sintering of the reacting pellets. Finally, five of the previous reactors have been connected in series to explore the influence of the changing inlet gas temperatures and concentrations on the dynamic performance of each storage mass.}, language = {en} } @article{WalterSchwanzerHagenetal., author = {Walter, Stefanie and Schwanzer, Peter and Hagen, Gunter and Rabl, Hans-Peter and Dietrich, Markus and Moos, Ralf}, title = {Soot Monitoring of Gasoline Particulate Filters Using a Radio-Frequency-Based Sensor}, series = {Sensors}, volume = {23}, journal = {Sensors}, number = {18}, publisher = {MDPI}, issn = {1424-8220}, doi = {10.3390/s23187861}, pages = {1 -- 19}, abstract = {Owing to increasingly stringent emission limits, particulate filters have become mandatory for gasoline-engine vehicles. Monitoring their soot loading is necessary for error-free operation. The state-of-the-art differential pressure sensors suffer from inaccuracies due to small amounts of stored soot combined with exhaust gas conditions that lead to partial regeneration. As an alternative approach, radio-frequency-based (RF) sensors can accurately measure the soot loading, even under these conditions, by detecting soot through its dielectric properties. However, they face a different challenge as their sensitivity may depend on the engine operation conditions during soot formation. In this article, this influence is evaluated in more detail. Various soot samples were generated on an engine test bench. Their dielectric properties were measured using the microwave cavity perturbation (MCP) method and compared with the corresponding sensitivity of the RF sensor determined on a lab test bench. Both showed similar behavior. The values for the soot samples themselves, however, differed significantly from each other. A way to correct for this cross-sensitivity was found in the influence of exhaust gas humidity on the RF sensor, which can be correlated with the engine load. By evaluating this influence during significant humidity changes, such as fuel cuts, it could be used to correct the influence of the engineon the RF sensor.}, language = {en} } @article{RillSchuderer, author = {Rill, Georg and Schuderer, Matthias}, title = {A Second-Order Dynamic Friction Model Compared to Commercial Stick-Slip Models}, series = {Modelling}, volume = {4}, journal = {Modelling}, number = {3}, publisher = {MDPI}, issn = {2673-3951}, doi = {10.3390/modelling4030021}, pages = {366 -- 381}, abstract = {Friction has long been an important issue in multibody dynamics. Static friction models apply appropriate regularization techniques to convert the stick inequality and the non-smooth stick-slip transition of Coulomb's approach into a continuous and smooth function of the sliding velocity. However, a regularized friction force is not able to maintain long-term stick. That is why dynamic friction models were developed in recent decades. The friction force depends herein not only on the sliding velocity but also on internal states. The probably best-known representative, the LuGre friction model, is based on a fictitious bristle but realizes a too-simple approximation. The recently published second-order dynamic friction model describes the dynamics of a fictitious bristle more accurately. It is based on a regularized friction force characteristic, which is continuous and smooth but can maintain long-term stick due to an appropriate shift in the regularization. Its performance is compared here to stick-slip friction models, developed and launched not long ago by commercial multibody software packages. The results obtained by a virtual friction test-bench and by a more practical festoon cable system are very promising. Thus, the second-order dynamic friction model may serve not only as an alternative to the LuGre model but also to commercial stick-slip models.}, language = {en} } @article{RillBauerKirchbeck, author = {Rill, Georg and Bauer, Florian and Kirchbeck, Mathias}, title = {VTT - a virtual test truck for modern simulation tasks}, series = {Vehicle system dynamics}, volume = {59}, journal = {Vehicle system dynamics}, number = {4}, publisher = {Taylor\&Francis}, doi = {10.1080/00423114.2019.1705356}, pages = {635 -- 656}, abstract = {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.}, language = {en} } @inproceedings{ArrietaCastroRill, author = {Arrieta Castro, Abel and Rill, Georg}, title = {Kinematic Versus Elasto-Kinematic Model of a Twistbeam Suspension}, series = {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}, booktitle = {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}, editor = {Orlova, Anna and Cole, David}, publisher = {Springer Nature}, doi = {10.1007/978-3-031-07305-2_59}, pages = {505 -- 605}, abstract = {The Twistbeam axle suspension is a cheap and robust layout for rear axles at front wheel driven midsize cars. Appropriate models have to take the elastic deformation of the torsion beam into account. A Finite Element approach requires detailed informations of the material properties and the shape which are usually only available in the final production stage. This paper presents a lumped mass model which can easily be integrated into a multibody vehicle model and can be used in the early stage of development. An approximation by the design kinematics further reduces the complexity of the model and considers only the kinematic properties of the Twistbeam suspension. Simulations using a nonlinear and three-dimensional vehicle model with different maneuvers, such as steady-state cornering, step steer input, and driving straight ahead on random road, demonstrate the performance and, in particular, the difference of the presented Twistbeam suspension models.}, language = {en} } @article{RillBauerTopcagic, author = {Rill, Georg and Bauer, Florian and Topcagic, Edin}, title = {Performance of leaf spring suspended axles in model approaches of different complexities}, series = {Vehicle System Dynamics}, volume = {60}, journal = {Vehicle System Dynamics}, number = {8}, publisher = {Taylor\&Francis}, doi = {10.1080/00423114.2021.1928249}, pages = {2871 -- 2889}, abstract = {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.}, language = {en} } @inproceedings{BuenteRillRuggaberetal., author = {B{\"u}nte, Tilman and Rill, Georg and Ruggaber, Julian and Tobol{\´a}ř, Jakub}, title = {Modelling and Validation of the TMeasy Tyre Model for Extreme Parking Manoeuvres}, series = {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}, booktitle = {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}, editor = {Orlova, Anna and Cole, David}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-07305-2}, doi = {10.1007/978-3-031-07305-2_94}, pages = {1015 -- 1025}, abstract = {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.}, language = {en} } @inproceedings{Rill, author = {Rill, Georg}, title = {A Three-Dimensional and Nonlinear Virtual Test Car}, series = {ENOC 2022, book of abstracts, 10th European Nonlinear Dynamics Conference: July 17-22, 2022, Lyon, France}, booktitle = {ENOC 2022, book of abstracts, 10th European Nonlinear Dynamics Conference: July 17-22, 2022, Lyon, France}, address = {Lyon}, pages = {49 -- 58}, abstract = {Virtual testing procedures have become a standard in vehicle dynamics. The increasing complexity of driver assistance sys- tems demand for more and more virtual tests, which are supposed to produce reliable results even in the limit range. As a consequence, simplified vehicle models, like the classical bicycle model or 4-wheel vehicle models, have to be replaced by a fully three-dimensional and nonlinear vehicle model, which also encompasses the details of the suspension systems. This paper presents a passenger car model, where the chassis, the four knuckles, and the four wheels are described by rigid bodies, the suspension system is modeled by the generic design kinematics, and the TMeasy tire model provides the tire forces and torques in all driving situations.}, 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{RillArrietaCastro, author = {Rill, Georg and Arrieta Castro, Abel}, title = {A Novel Approach for Parametrization of Suspension Kinematics}, series = {Advances in Dynamics of Vehicles on Roads and Tracks: Proceedings of the 26th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2019), August 12-16, 2019, Gothenburg, Sweden}, booktitle = {Advances in Dynamics of Vehicles on Roads and Tracks: Proceedings of the 26th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2019), August 12-16, 2019, Gothenburg, Sweden}, editor = {Klomp, Matthijs and Bruzelius, Fredrik and Nielsen, Jens and Hillemyr, Angela}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-030-38076-2}, doi = {10.1007/978-3-030-38077-9_210}, pages = {1848 -- 1857}, abstract = {n the automotive industry, simulations are needed to analyse the dynamics of vehicles and also of its main components and subsystems, e.g. tires, brakes and suspension systems. These simulations are required for an early-stage development and in consequence, they must deliver realistic results. Suspension systems plays a key role in comfort and safety of road vehicles. They usually consist of rigid links and force elements that are arranged with a specific topology. In addition, some of their functionalities are to carry the weight of the car and the passengers, and maintain a correct wheel alignment. In simulations involving suspension systems, lookup-tables are frequently used. They are obtained from a Kinematic and Compliance (KnC) test and then standardized for a specific vehicle simulation software. Nonetheless, lookup-tables require a reasonable number of characteristic points. Additionally, derivatives, interpolation, and extrapolation are not necessarily smooth. This produces results that depend on the interpolation technique and may be inaccurate. In this paper, a novel method called "design kinematics" is proposed. This method can describe the kinematic properties of almost any type of suspension systems. Comparisons with an analytic calculation and a KnC measurement shown that the design kinematics is able to represent the kinematic and compliance properties of suspension systems extremely well and very efficiently.}, language = {en} } @article{Rill, author = {Rill, Georg}, title = {Sophisticated but quite simple contact calculation for handling tire models}, series = {Multibody system dynamics}, volume = {45}, journal = {Multibody system dynamics}, number = {2}, publisher = {Springer Nature}, organization = {SPRINGER}, doi = {10.1007/s11044-018-9629-4}, pages = {131 -- 153}, abstract = {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.}, language = {en} } @inproceedings{RillArrietaCastro, author = {Rill, Georg and Arrieta Castro, Abel}, title = {The Influence of Axle Kinematics on Vehicle Dynamics}, series = {Interdisciplinary Applications of Kinematics. Proceedings of the Third International Conference (IAK)}, volume = {71}, booktitle = {Interdisciplinary Applications of Kinematics. Proceedings of the Third International Conference (IAK)}, editor = {Kecskem{\´e}thy, Andr{\´e}s and Geu Flores, Francisco and Carrera, Eliodoro and Elias, Dante A.}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-030-16422-5}, doi = {10.1007/978-3-030-16423-2_2}, pages = {23 -- 31}, abstract = {The automotive industry employs many different kinds of axle suspension systems at modern passenger cars. Important criteria are costs, space requirements, kinematic properties, and compliance attributes. This paper illustrates that in particular the kinematic properties of a suspension system have a significant influence on the dynamics of vehicles. As a consequence, the kinematics of a suspension system must be modeled very precisely and nonlinear. Typical kinematical features of a suspension system are discussed by analyzing the most common double wishbone axle suspension system. The influence of the axle kinematics on vehicle dynamics is finally demonstrated by simulation results generated with a fully nonlinear and three-dimensional multibody vehicle model.}, language = {en} } @inproceedings{Rill, author = {Rill, Georg}, title = {TMeasy 6.0-A handling tire model that incorporates the first two belt eigenmodes}, series = {Proceedings of the XI International Conference on Structural Dynamics (EURODYN 2020): Athens, Greece, 23.11.2020 - 26.11.2020}, booktitle = {Proceedings of the XI International Conference on Structural Dynamics (EURODYN 2020): Athens, Greece, 23.11.2020 - 26.11.2020}, publisher = {EASD Procedia}, doi = {10.47964/1120.9054.18673}, pages = {676 -- 689}, abstract = {TMeasy 6.0, an extension to the standard TMeasy tire model of version 5.3, takes the relevant first two rigid body eigenmodes of the belt into consideration. These modes represent the in plane longitudinal and rotational movements of the belt relative to the rim. The dynamics of the longitudinal force is of higher order then and reproduces the tire wheel vibrations, required for indirect tire-pressure monitoring systems (iTPMS), sufficiently well. A tailored implicit solver, which takes the stiff coupling between the longitudinal force and the belt motions into account, still provides real-time performance in addition. Simulation examples show that a rigid body vehicle model equipped with TMeasy 6.0 makes it possible to investigate second generation indirect tire-pressure monitoring systems.}, language = {en} } @book{RillArrietaCastro, author = {Rill, Georg and Arrieta Castro, Abel}, title = {Road Vehicle Dynamics}, publisher = {CRC Press}, address = {Boca Raton, Fla.}, isbn = {9780429244476}, doi = {10.1201/9780429244476}, abstract = {Road Vehicle Dynamics: Fundamentals and Modeling with MATLAB®, Second Edition combines coverage of vehicle dynamics concepts with MATLAB v9.4 programming routines and results, along with examples and numerous chapter exercises. Improved and updated, the revised text offers new coverage of active safety systems, rear wheel steering, race car suspension systems, airsprings, four-wheel drive, mechatronics, and other topics. Based on the lead author's extensive lectures, classes, and research activities, this unique text provides readers with insights into the computer-based modeling of automobiles and other ground vehicles. Instructor resources, including problem solutions, are available from the publisher.}, subject = {Fahrdynamik}, language = {en} } @incollection{Rill, author = {Rill, Georg}, title = {Multibody Systems and Simulation Techniques}, series = {Vehicle Dynamics of Modern Passenger Cars}, booktitle = {Vehicle Dynamics of Modern Passenger Cars}, editor = {Lugner, Peter}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-319-79007-7}, doi = {10.1007/978-3-319-79008-4_6}, pages = {309 -- 375}, abstract = {This part begins with an introduction to Multibody Systems (MBS). It presents the elements of MBS and discusses different modeling aspects. Then, different methods to generate the equations of motion are presented. Solvers for ordinary differential equations (ODE) as well as differential algebraic equations (DAE) are discussed. Finally, techniques for "online" and "offline" simulations including real-time applications are presented like necessary for car development. Special examples show the connection between simulation and test results.}, language = {en} } @incollection{ArrietaCastroRillWeber, author = {Arrieta Castro, Abel and Rill, Georg and Weber, Hans I.}, title = {Development of a Robust Integrated Control System to Improve the Stability of Road Vehicles}, series = {Multibody Mechatronic Systems}, volume = {54}, booktitle = {Multibody Mechatronic Systems}, editor = {Carvalho, Jo{\~a}o Carlos Mendes and Martins, Daniel and Simoni, Roberto and Simas, Henrique}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-67566-4}, doi = {10.1007/978-3-319-67567-1_48}, pages = {506 -- 516}, abstract = {Nowadays, new technologies are pushing the road vehicle limits further. Promising applications, e.g., self-driving cars, require a suitable control system that can maintain the vehicle's stability in critical scenarios. In most of current cars, the control systems actuates independently, meaning there is not a coordination or data sharing between them. This approach can produce a conflict between these standalone controllers and thus, no improvements on the vehicle's stability are achieved or even a worse scenario can be generated. In order to overcome these problems, an integrated approach is developed in this work. This integration, defined in this work as Integrated Control (IC), is done by an intelligence coordination of all standalone controllers inside the vehicle, i.e., Anti-Lock Braking System (ABS), Electronic Stability Program (ESP) and Four-Wheel Steering System (4WS). The ABS model was built using Fuzzy logic, for which only three rules were necessary to get a good performance. To design the ESP and the 4WS, the simple handling vehicle model was used as a reference behavior. The IC was designed using the hierarchical approach with two layers, i.e., the upper and lower layer. The upper one, observes the side slip angle and depends of its value the upper layer triggers the ESP or the 4WS. Finally, in order to prove the improvements of the IC system over the non-integrated approach, a full-size vehicle model was used to perform simulation in run-off-road and μ-split scenarios.}, language = {en} } @inproceedings{ArrietaCastroChavesRilletal., author = {Arrieta Castro, Abel and Chaves, Rafael B. and Rill, Georg and Weber, Hans I.}, title = {Use of Integrated Control to Enhance the Safety of Vehicles in Run-Off-Road Scenarios}, series = {Proceedings of DINAME 2017 : Selected Papers of the XVII International Symposium on Dynamic Problems of Mechanics}, booktitle = {Proceedings of DINAME 2017 : Selected Papers of the XVII International Symposium on Dynamic Problems of Mechanics}, editor = {Fleury, Agenor de T. and Rade, Domingos A. and Kurka, R. G.}, edition = {1. Auflage}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-91217-2}, issn = {2195-4356}, doi = {10.1007/978-3-319-91217-2_30}, pages = {431 -- 443}, abstract = {In this work, an integrated vehicle control system (IC) is tested in run-off-road scenarios. The integrated approach was employed in order to coordinate vehicle control systems, i.e. the Anti-Lock Brake System (ABS), Four-wheel Steering (4WS) and the Electronic Stability Program (ESP). To perform a run-off-road maneuver, a fuzzy virtual test driver was designed. By receiving the lateral position of an obstacle and the vehicle's relative yaw angle, the virtual test driver is capable of following a reference trajectory. Furthermore, to test the performance of the standalone controllers, i.e. ABS, ESP and 4WS, individual maneuvers are performed using a multibody vehicle model. The vehicle without any coordination between the control systems is used as reference. For the simulation results, it is concluded that the IC improves the vehicle stability and maneuverability in comparison with the non-integrated approach.}, language = {en} } @article{Rill2017, author = {Rill, Georg}, title = {Reducing the cornering resistance by torque vectoring (X International Conference on Structural Dynamics, EURODYN 2017)}, series = {Procedia Engineering}, volume = {199}, journal = {Procedia Engineering}, publisher = {Elsevier}, doi = {10.1016/j.proeng.2017.09.393}, pages = {3284 -- 3289}, year = {2017}, abstract = {Usually, torque vectoring is used to reduce a significant understeer behavior at high speed cornering. Thus, providing larger vehicles with a sportive touch. Even on typical front wheel driven cars torque vectoring control is available now. Torque vectoring is nearly a standard on electric driven vehicles. Complex control and optimization strategies are applied to improve the maneuverability in particular or to enhance the driving behavior and reduce the energy consumption in addition. This paper shows, that a quite simple strategy will enhance the maneuverability and simultaneously reduce the cornering resistance in sharp bends. At first, a case study with a fully non-linear and three-dimensional vehicle model is performed. It turned out that a full drive torque shift to the outer wheels improves the maneuverability and reduces the cornering resistance in addition. This results are verified by an optimization performed with a simpler four-wheeled handling model. Here, the front steering angles and the driving torques at each of the four wheels are considered as free parameters. Minimizing the cornering resistance by taking the equations of motion for the four-wheeled handling model as constraints will deliver an optimal set of parameters then.}, language = {en} } @inproceedings{HacklHirschbergLexetal., author = {Hackl, Andreas and Hirschberg, W. and Lex, C. and Rill, Georg}, title = {Tyre type dependent transient force behaviour by means of a maxwell model}, series = {The Dynamics of Vehicles on Roads and Tracks : Proceedings of the 25th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2017), Rockhampton, Queensland, Australia, 14-18 August 2017}, booktitle = {The Dynamics of Vehicles on Roads and Tracks : Proceedings of the 25th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2017), Rockhampton, Queensland, Australia, 14-18 August 2017}, editor = {Spiryagin, Maksym and Gordon, Timothy and Cole, Colin and McSweeney, Tim}, publisher = {CRC Press}, address = {London}, isbn = {1351057170}, doi = {10.1201/9781315265506}, pages = {157 -- 162}, abstract = {The present papers deals with the usability of an extended Maxwell model to describe the tyre dynamics during transient driving manoeuvres. In the present article, the para-metrisation process of a dynamic tyre model is investigated in a first step, using measurement data of tyre forces from a flat trac tyre test bench, (IABG 2016). Two tyre types of dimensions 255/50 R19 and 175/55 R15 are used. The practical applicability is discussed, considering the measurement procedure and the parameter optimisation process. In a second step, the performance of the dynamic tyre model is validated using measurements of manoeuvres under higher dynamic excitation. As a last step, an outlook is given on further research planned in which the presented model and parametrisation are adapted to a larger frequency range.}, language = {en} } @inproceedings{Rill, author = {Rill, Georg}, title = {Real-Time capable Multibody Model of dual Truck Front Axles}, series = {Proceedings of DINAME 2023 - Selected Papers of the XIX International Symposium on Dynamic Problems of Mechanics, 26 Feb - 03 Mar 2023, Piren{\´o}polis, Brazil}, booktitle = {Proceedings of DINAME 2023 - Selected Papers of the XIX International Symposium on Dynamic Problems of Mechanics, 26 Feb - 03 Mar 2023, Piren{\´o}polis, Brazil}, editor = {Fleury, Agenor de T.}, publisher = {Springer}, abstract = {Dual front steering axles are quite common in multi-axled heavy duty trucks. In standard layouts of such axle combinations, the steer motions of the wheels depend not only on the rotation of the steering wheel but also on the movements of the axles. As a consequence, the model complexity of the steering system should match with the complexity of the suspension model. The development of new technologies like advanced driver assistance systems or autonomous driving can only be accomplished efficiently using extensive simulation methods. Such kind of applications demand for computationally efficient vehicle models. This paper presents a steering system model for dual front axles of heavy duty trucks which supplements the suspension model of the axles. The model takes the torsional compliance of the steering column as well as the stiffness of the tie rods and the coupling rod into account. A quasi-static solution provides a straight forward computation including the partial derivatives required for an efficient implicit solver. The steering system model matches perfectly with comparatively lean, but sufficiently accurate multibody suspension models.}, language = {en} } @techreport{MichaelSternerMareikeJentschUweHolzhammer, author = {Michael Sterner, and Mareike Jentsch, and Uwe Holzhammer,}, title = {Energiewirtschaftliche und {\"o}kologische Bewertung eines Windgas-Angebotes}, publisher = {Fraunhofer Institute for Energy Economics and Energy System Technology}, address = {Kassel}, doi = {10.13140/RG.2.2.25093.68328}, abstract = {In this technical report, (1) the benefits of the new technology for future energy supply are discussed, (2) the climate protection effect of wind gas is discussed, and (3) a reasonable use of wind energy for gas generation is analyzed. In particular, windgas in the heat market is discussed in the utilization cascade of wind energy. The new "power-to-gas" concept opens up completely new possibilities for the integration of renewable energies and for coupling the electricity and gas grids. The Sabatier process, which has been known for 100 years, was first developed for this purpose in 2008 under the leadership of the Center for Solar Energy and Hydrogen Research and Fraunhofer IWES (formerly ISET) with electrolysis to create the "power-to-gas" concept for energy storage. A first pilot plant was built by ZSW Stuttgart on behalf of SolarFuel in 2009. This plant proves the technical feasibility of the new technology. Renewable gas is stored, transported and used as required as control and reserve energy via reconversion, e.g. in combined cycle power plants. In this way, decentrally generated renewable electricity is converted into a CO2 -neutral energy carrier with high energy density. The key advantage of renewable methane is the use of existing infrastructure such as gas grids, gas storage and end-use equipment for the integration of renewable energy. Technologies for natural gas are state of the art and commercially available. Methane also has three times the energy density of hydrogen.}, language = {en} } @techreport{ZacherlWopperMieslingeretal., author = {Zacherl, Florian and Wopper, Christoph and Mieslinger, Johann and Peis, Michael and Rabl, Hans-Peter}, title = {Schlussbericht zum Verbundvorhaben NAMOSYN: Nachhaltige Mobilit{\"a}t durch synthetische Kraftstoffe}, address = {Regensburg}, pages = {156}, abstract = {Im Labor f{\"u}r Verbrennungsmotoren und Abgasnachbehandlung der OTH-Regensburg sollten im Zuge des NAMOSYN-Projektes zwei Vertreter klimaneutraler Kraftstoffe an verschiedenen Systempr{\"u}fst{\"a}nden (Motor-, Einspritzpr{\"u}fstand, optisch zug{\"a}ngliche Einspritzkammer, …) und mit Hilfe von Simulationsmethoden f{\"u}r den Einsatz in bestehenden Verbrennungsmotoren untersucht werden. Synthetische Kraftstoffe aus der Gruppe der Oxymethylenether (OME) stellen eine CO2-neutrale Alternative zu fossilem Dieselkraftstoff dar. F{\"u}r Ottomotoren wurde untersucht, ob der synthetische Kraftstoff DMC/MeFo (Dimethylcarbonat \& Methylformiat) einen Ersatz f{\"u}r Ottokraftstoff darstellen kann, bzw. eine Drop-In-F{\"a}higkeit gegeben ist. Die OTH Regensburg bearbeitete 2 unabh{\"a}ngige Teilvorhaben zur motorischen Testung von synthetischen Kraftstoffen: „FC 1A: Motorische Testung von OME" und „FC 2: Untersuchung von C1-Oxygenaten f{\"u}r Ottomotoren". Die Projektlaufzeit betrug 3,5 Jahre, inkl. kostenneutraler Verl{\"a}ngerung um 6 Monate aufgrund der Corona-Pandemie. Im FC1A "AP2-Nachr{\"u}stung Dieselmotoren" der OTH Regensburg lag der Fokus auf der Erforschung der Potentiale und der Umr{\"u}stung eines Einzylinder-Dieselmotors mit Pumpe-Leitung-D{\"u}se-(PLD)-Einspritzsystem des Projektpartners Motorenfabrik Hatz GmbH und Co. KG f{\"u}r OME-Betrieb. Im AP2.1 wurden umfangreiche Daten gesammelt und Simulationsmodelle des Motors und PLD-Einspritzsystems erstellt und mit Dieselkraftstoff und OME validiert. Nachfolgend wurden Parameterstudien zur Geometrie des Einspritzsystems und der physikalischen Eigenschaften von OME durchgef{\"u}hrt. In AP2.2 und AP2.3 wurden umfangreiche Untersuchungen an einem Motor- und Einspritzsystempr{\"u}fstand mit Diesel und OME durchgef{\"u}hrt und der Steuerger{\"a}tedatensatz f{\"u}r den OME-Betrieb optimiert. Die Ergebnisse zeigen, dass die Umstellung des Kraftstoffs auf OME, insbesondere bei einfachen Motoren mit rudiment{\"a}rer Einspritztechnik und ohne Mittel zur NOx-Reduzierung (keine AGR oder SCR), ein enormes Potenzial zur Steigerung des Wirkungsgrads bei gleichzeitiger Reduzierung aller regulierten Schadstoffe (NOx, 𝑃N, 𝑃M, CO und 𝑉OC) er{\"o}ffnet. Die Ergebnisse und generierten Simulationsmodelle unterst{\"u}tzen eine schnelle Serienentwicklung und Einf{\"u}hrung von OME-Umr{\"u}stl{\"o}sungen. In FC 2 werden die vielversprechenden Kraftstoffe Methylformiat (MeFo) und Dimethylcarbonat (DMC) motorisch getestet. Untersuchungen am Kraftstoffsystem und wichtigen Komponenten dienen als Grundlage f{\"u}r das AP3. Im AP3 wird die Machbarkeit der DMC/MeFo-Verbrennung am Vollmotor demonstriert und die erwarteten Emissionsvorteile gegen{\"u}ber herk{\"o}mmlichen Ottokraftstoffen gezeigt. Abweichend von der urspr{\"u}nglichen Planung werden an der OTH Regensburg Kraftstoffblends aus Benzin und MeFo untersucht, um den Einsatzbereich des Kraftstoffs zu erweitern. In AP5 werden potentielle Mischungsverh{\"a}ltnisse analysiert und die Eigenschaften der ausgew{\"a}hlten Kraftstoffmischungen an einem Einspritzratenpr{\"u}fstand, an der Einspritzkammer und am Vollmotor untersucht. Es werden Einspritzverhalten, Gemischaufbereitung und Abgasemissionen bewertet. Zudem wird eine Kraftstoffmischanlage entwickelt und ein optischer Zugang am Vollmotor erm{\"o}glicht. Eine {\"O}lverd{\"u}nnungsmesstechnik wird eingesetzt, um den Kraftstoffeintrag ins Motor{\"o}l zu untersuchen}, language = {de} } @article{SchuemannMorichKaufholdetal., author = {Sch{\"u}mann, Malte and Morich, J. and Kaufhold, T. and B{\"o}hm, Valter and Zimmermann, Klaus and Odenbach, Stefan}, title = {A mechanical characterisation on multiple timescales of electroconductive magnetorheological elastomers}, series = {Magnetism and Magnetic Materials}, volume = {453}, journal = {Magnetism and Magnetic Materials}, number = {May}, publisher = {Elsevier}, doi = {10.1016/j.jmmm.2018.01.029}, pages = {198 -- 205}, abstract = {Magnetorheological elastomers are a type of smart hybrid material which combines elastic properties of a soft elastomer matrix with magnetic properties of magnetic micro particles. This leads to a material with magnetically controllable mechanical properties of which the magnetorheological effect is the best known. The addition of electroconductive particles to the polymer mix adds electrical properties to the material behaviour. The resulting electrical resistance of the sample can be manipulated by external magnetic fields and mechanical loads. This results in a distinct interplay of mechanical, electrical and magnetic effects with a highly complex time behaviour. In this paper a mechanical characterisation on multiple time scales was conducted to get an insight on the short and long-term electrical and mechanical behaviour of this novel material. The results show a complex resistivity behaviour on several timescales, sensitive to magnetic fields and strain velocity. The observed material exhibits fatigue and relaxation behaviour, whereas the magnetorheological effect appears not to interfere with the piezoresistive properties.}, language = {en} } @inproceedings{KetterlHeinrichReitmeieretal., author = {Ketterl, Hermann and Heinrich, Tobias and Reitmeier, Torsten and Hoelscher, Clemens}, title = {Emissionsabh{\"a}ngige Leistungsregelung f{\"u}r BHKW's}, series = {Tagungsband AALE 2020: Automatisierung und Mensch-Technik-Interaktion, 17. Fachkonferenz, 4. bis 6. M{\"a}rz 2020, Leipzig}, volume = {2020}, booktitle = {Tagungsband AALE 2020: Automatisierung und Mensch-Technik-Interaktion, 17. Fachkonferenz, 4. bis 6. M{\"a}rz 2020, Leipzig}, editor = {J{\"a}kel, Jens and Thiel, Robert}, publisher = {VDE-Verlag}, isbn = {978-3-8007-5180-8}, pages = {7}, language = {de} } @misc{OPUS4-6542, title = {Energieforschung}, edition = {Ausgabe 2023}, publisher = {OTH Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg / Regensburg Center of Energy and Resources (RCER)}, doi = {10.35096/othr/pub-6542}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-65422}, abstract = {{\"U}ber uns Das Regensburg Center of Energy and Resources (RCER) b{\"u}ndelt seit 2012 die Aktivit{\"a}ten der Ostbayerischen Technischen Hochschule Regensburg (OTH Regensburg) und der regionalen Wirtschaftsunternehmen auf dem Strategiefeld „Energie und Ressourcen". Mission: Energieforschung: vernetzen, voranbringen, vermitteln Das RCER f{\"o}rdert die Vernetzung verschiedener Disziplinen der Energieforschung innerhalb der OTH Regensburg und mit externen Partnern (Firmen, F{\"o}rdertr{\"a}gern, Forschungsinstitutionen, {\"o}ffentlichen Einrichtungen). Das RCER ist Ihr Partner beim Voranbringen von Kooperationen und Forschungsvorhaben durch Unterst{\"u}tzung in der Antragsphase, bei der Einwerbung von Projektmitteln und Projektbegleitung im Energiebereich. Das RCER steht f{\"u}r die Vermittlung von Know-how, Basiswissen, aktuellen Fragen und den Technologietransfer rund um das Thema Energie zwischen Wissenschaft, Wirtschaft, Gesellschaft und Politik. Vision Wir sind Ihr erster Ansprechpartner und Motor f{\"u}r innovative Energieforschung. Werte Verl{\"a}sslichkeit, Kompetenz, Verantwortungsbewusstsein.Regional verwurzelt und weltoffen}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Strom - W{\"a}rme - Verkehr - Industrie: das Zusammenspiel der Sektoren {\"u}ber Power-to-X}, series = {Deutscher Ingenieurtag 2021, D{\"u}sseldorf 20. Mai 2021}, journal = {Deutscher Ingenieurtag 2021, D{\"u}sseldorf 20. Mai 2021}, publisher = {VDI-Verlag}, language = {de} } @article{MikhaeilGadererDawoud, author = {Mikhaeil, Makram and Gaderer, Matthias and Dawoud, Belal}, title = {On the application of adsorber plate heat exchangers in thermally driven chillers}, series = {Applied Thermal Engineering}, volume = {220}, journal = {Applied Thermal Engineering}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2022.119713}, abstract = {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.}, language = {en} } @article{FrazzicaPalombaDawoud, author = {Frazzica, Andrea and Palomba, Valeria and Dawoud, Belal}, title = {Thermodynamic Performance of Adsorption Working Pairs for Low-Temperature Waste Heat Upgrading in Industrial Applications}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {8}, publisher = {MDPI}, doi = {10.3390/app11083389}, abstract = {The present work aims at the thermodynamic analysis of different working pairs in adsorption heat transformers (AdHT) for low-temperature waste heat upgrade in industrial processes. Two different AdHT configurations have been simulated, namely with and without heat recovery between the adsorbent beds. Ten working pairs, employing different adsorbent materials and four different refrigerants, have been compared at varying working boundary conditions. The effects of heat recovery and the presence of a temperature gradient for heat transfer between sinks/sources and the AdHT components have been analyzed. The achieved results demonstrate the possibility of increasing the overall performance when internal heat recovery is implemented. They also highlight the relevant role played by the existing temperature gradient between heat transfer fluids and components, that strongly affect the real operating cycle of the AdHT and thus its expected performance. Both extremely low, i.e., 40-50 degrees C, and low (i.e., 80 degrees C) waste heat source temperatures were investigated at variable ambient temperatures, evaluating the achievable COP and specific energy. The main results demonstrate that optimal performance can be achieved when 40-50 K of temperature difference between waste heat source and ambient temperature are guaranteed. Furthermore, composite sorbents demonstrated to be the most promising adsorbent materials for this application, given their high sorption capacity compared to pure adsorbents, which is reflected in much higher achievable specific energy.}, language = {en} } @article{ThemaWeidlichKauletal., author = {Thema, Martin and Weidlich, Tobias and Kaul, Anja and B{\"o}llmann, Andrea and Huber, Harald and Bellack, Annett and Karl, J{\"u}rgen and Sterner, Michael}, title = {Optimized biological CO2-methanation with a pure culture of thermophilic methanogenic archaea in a trickle-bed reactor}, series = {Bioresource Technology}, journal = {Bioresource Technology}, number = {333}, publisher = {Elsevier}, doi = {10.1016/j.biortech.2021.125135}, abstract = {In this study, a fully automated process converting hydrogen and carbon dioxide to methane in a high temperature trickle-bed reactor was developed from lab scale to field test level. The reactor design and system performance was optimized to yield high methane content in the product gas for direct feed-in to the gas grid. The reaction was catalyzed by a pure culture of Methanothermobacter thermoautotrophicus IM5, which formed a biofilm on ceramic packing elements. During 600 h in continuous and semi-continuous operation in countercurrent flow, the 0.05 m3 reactor produced up to 95.3 \% of methane at a methane production rate of 0.35 mCH43mR-3h-1. Adding nitrogen as carrier gas during startup, foam control and dosing of ammonium and sodium sulfide as nitrogen and sulfur source were important factors for process automation.}, language = {en} } @article{GaertnerRankHeberletal., author = {G{\"a}rtner, Sebastian and Rank, Daniel and Heberl, Michael and Gaderer, Matthias and Dawoud, Belal and Haumer, Anton and Sterner, Michael}, title = {Simulation and Techno-Economic Analysis of a Power-to-Hydrogen Process for Oxyfuel Glass Melting}, series = {Energies}, volume = {14}, journal = {Energies}, number = {24}, publisher = {MDPI}, doi = {10.3390/en14248603}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-22713}, abstract = {As an energy-intensive industry sector, the glass industry is strongly affected by the increasingly stringent climate protection targets. As established combustion-based production systems ensure high process stability and glass quality, an immediate switch to low greenhouse gas emission processes is difficult. To approach these challenges, this work investigates a step-by-step integration of a Power-to-Hydrogen concept into established oxyfuel glass melting processes using a simulation approach. This is complemented by a case study for economic analysis on a selected German glass industry site by simulating the power production of a nearby renewable energy park and subsequent optimization of the power-to-hydrogen plant performance and capacities. The results of this study indicate, that the proposed system can reduce specific carbon dioxide emissions by up to 60\%, while increasing specific energy demand by a maximum of 25\%. Investigations of the impact of altered combustion and furnace properties like adiabatic flame temperature (+25 °C), temperature efficiency (∆ξ = -0.003) and heat capacity flow ratio (∆zHL = -0.009) indicate that pure hydrogen-oxygen combustion has less impact on melting properties than assumed so far. Within the case study, high CO2 abatement costs of 295 €/t CO2-eq. were determined. This is mainly due to the insufficient performance of renewable energy sources. The correlations between process scaling and economic parameters presented in this study show promising potential for further economic optimization of the proposed energy system in the future.}, language = {en} } @article{SchorrZentnerZimmermannetal., author = {Schorr, Philipp and Zentner, Lena and Zimmermann, Klaus and B{\"o}hm, Valter}, title = {Jumping locomotion system based on a multistable tensegrity structure}, series = {Mechanical systems and signal processing}, journal = {Mechanical systems and signal processing}, number = {152}, publisher = {Elsevier}, doi = {10.1016/j.ymssp.2020.107384}, abstract = {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.}, language = {en} } @article{EmbergerAltmannGebhardetal., author = {Emberger, Peter and Altmann, Robert and Gebhard, J{\"u}rgen and Thuneke, Klaus and Winkler, Markus and T{\"o}pfer, Georg and Rabl, Hans-Peter and Remmele, Edgar}, title = {Combustion characteristics of pure rapeseed oil fuel after injection in a constant volume combustion chamber with a non-road mobile machinery engine solenoid injector}, series = {Fuel}, journal = {Fuel}, number = {320}, publisher = {Elsevier}, doi = {10.1016/j.fuel.2022.123979}, abstract = {Pure rapeseed oil fuel (R100) according to standard DIN 51605 is a greenhouse gas saving option for the mobility sector. With its high energy density close to diesel fuel, R100 is suitable to operate non-road mobile machinery with a high power demand and long operating time, where electric drives reach their limits. Advantages are indicated for its use in environmentally sensitive areas like agriculture since R100 is highly biodegradable and non-toxic. However, R100 is characterised by differing physical and chemical properties compared to diesel. The objective of the research is to investigate the differences in the ignition and combustion behaviour of R100 compared to diesel fuel (DF). For this purpose, a constant volume combustion chamber is used, which is equipped with a modern solenoid injector for engines of non-road mobile machinery. The researched injector shows a different hydraulic behaviour when using R100 compared to DF in that the injected fuel mass is lower with R100 than with DF. In combination with the 14 \% by mass lower calorific value, less energy output is determined with R100. When varying the injection pressure, the impact on the ignition delay and combustion behaviour is much higher for R100 than for DF. Specifically, an increase of the injection pressure supports mixture preparation and thus partially compensates the differing physical properties of R100. The results of ignition delay measurements and net heat release analysis are as follows: At low load conditions with low injection pressure as well as a low combustion chamber temperature and pressure, R100 ignites later and shows a further delayed combustion compared to diesel. The opposite is observed for medium and high load conditions, where R100 ignites faster and without delayed combustion in comparison to DF. Thus, an adjustment of the heat release of R100 at the same level as for DF is possible by modifying the injection strategy. The research shows that for an optimised combustion of R100 the injection settings must be adjusted for every operation point separately. The results indicate how the injection parameters should be adjusted for different load conditions to realise a high-quality engine calibration for R100.}, language = {en} } @inproceedings{TremmelNaglerKutteretal., author = {Tremmel, Florian and Nagler, O. and Kutter, C. and Holmer, Rainer}, title = {Smart Cantilever Probe with Integrated Force and Acoustic Emission Sensor}, series = {2023 IEEE SENSORS, Vienna, Austria, 10/29/2023 - 11/1/2023}, booktitle = {2023 IEEE SENSORS, Vienna, Austria, 10/29/2023 - 11/1/2023}, publisher = {IEEE}, isbn = {979-8-3503-0387-2}, doi = {10.1109/SENSORS56945.2023.10325021}, pages = {1 -- 4}, abstract = {Acoustic emission (AE) testing recently found its application in the wafer testing sector of the semiconductor industry. To find out the mechanical robustness of semiconductor devices, contact pads on the chip surface are intentionally overstressed with an indenter tip and the appearing oxide cracks are detected with help of the generated AE signals. This is done in a customized test bench with a patented sensor-indenter system. This paper presents an improved version of the measurement setup that solves certain disadvantages of it and can be used in a standard wafer prober. The main components of the developed sensor system are a strain gauge for contact force measurement and a piezoelectric sensor element for AE signal detection. Both components are integrated on a cantilever beam which has an exchangeable indenter tip at its free end. The cantilever probe is electrically conductive to enable electrical tests via the indenter tip. This smart sensor-cantilever combination (SCC) can be mounted with several adapter components on a carrier plate to place it in a wafer prober. For both sensor elements amplifier circuits are developed to enhance their signal-to-noise ratios (SNRs). A prototype setup is shown together with simulated and experimental results to demonstrate its performance. The mechanical properties of the cantilever, as well as the force sensor and the AE crack signals, already fulfill the requirements for an implementation in a wafer prober. To further improve the sensor resolutions and detection limits, several optimizations regarding the design of the SCC are in progress.}, language = {en} } @article{ThemaBauerSterner, author = {Thema, Martin and Bauer, Franz and Sterner, Michael}, title = {Power-to-Gas: Electrolysis and methanation status review}, series = {Renewable and Sustainable Energy Reviews}, volume = {112}, journal = {Renewable and Sustainable Energy Reviews}, number = {7}, publisher = {Elsevier}, doi = {10.1016/j.rser.2019.06.030}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-26238}, pages = {775 -- 787}, abstract = {This review gives a worldwide overview on Power-to-Gas projects producing hydrogen or renewable substitute natural gas focusing projects in central Europe. It deepens and completes the content of previous reviews by including hitherto unreviewed projects and by combining project names with details such as plant location. It is based on data from 153 completed, recent and planned projects since 1988 which were evaluated with regards to plant allocation, installed power development, plant size, shares and amounts of hydrogen or substitute natural gas producing examinations and product utilization phases. Cost development for electrolysis and carbon dioxide methanation was analyzed and a projection until 2030 is given with an outlook to 2050. The results show substantial cost reductions for electrolysis as well as for methanation during the recent years and a further price decline to less than 500 euro per kilowatt electric power input for both technologies until 2050 is estimated if cost projection follows the current trend. Most of the projects examined are located in Germany, Denmark, the United States of America and Canada. Following an exponential global trend to increase installed power, today's Power-to-Gas applications are operated at about 39 megawatt. Hydrogen and substitute natural gas were investigated on equal terms concerning the number of projects.}, language = {en} } @article{MonkmanSindersbergerPrem, author = {Monkman, Gareth J. and Sindersberger, Dirk and Prem, Nina}, title = {Magnetically enhanced photoconductive high voltage control}, series = {ISSS Journal of Micro and Smart Systems}, volume = {11}, journal = {ISSS Journal of Micro and Smart Systems}, publisher = {Springer Nature}, doi = {10.1007/s41683-021-00088-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-30606}, pages = {317 -- 328}, abstract = {The recent surge of interest in electrostatic actuators, particularly for soft robotic applications, has placed increasing demands on high voltage control technology. In this respect, optoelectronic bidirectional switching and analogue regulation of high voltages is becoming increasingly important. One common problem is the leakage current due to dark resistance of the material or device used. Another is the physical size of such elements. However, their ability to provide galvanic separation makes them a very attractive alternative to conventional (wired) semiconductor elements. This paper gives an overview of available methods and devices before introducing a concept based on the combination of photoresistive and magnetoresistive effects in Gallium Arsenide that are potentially applicable to other semiconductor materials.}, language = {en} } @article{HaugVetter, author = {Haug, Sonja and Vetter, Miriam}, title = {Altersgerechtes Wohnen im Quartier}, series = {Standort - Zeitschrift f{\"u}r angewandte Geographie}, volume = {45}, journal = {Standort - Zeitschrift f{\"u}r angewandte Geographie}, publisher = {Springer Nature}, issn = {1432-220X}, doi = {10.1007/s00548-020-00678-3}, pages = {11 -- 17}, abstract = {Im Alter nimmt das Quartier aufgrund geringerer Aktionsradien an Bedeutung zu. Der Beitrag befasst sich mit der Frage, welche Besonderheiten sich bei Senioren-Haushalten im Hinblick auf Wohnen und soziale Teilhabe zeigen. Aus dem Projekt MAGGIE werden Ergebnisse einer schriftlichen Haushaltsbefragung (N=195) in der Wohngenossenschaft Margaretenau Regensburg dargestellt. Hierbei wird auf die aktuelle und zuk{\"u}nftige Wohnsituation, den Ver{\"a}nderungsbedarf, den Wunsch nach Gemeinschaftsangeboten und die soziale Einbettung eingegangen. Es zeigt sich eine geringe Ver{\"a}nderungsbereitschaft und ein {\"u}berdurchschnittlich hohes Maß an lokalem Sozialkapital. Am Ende werden Schlussfolgerungen f{\"u}r das Sanierungs- und Quartiersmanagement gezogen.}, subject = {Alter}, language = {de} }