@article{SykoraDiamantidisHolickyetal., author = {S{\´y}kora, Miroslav and Diamantidis, Dimitris and Holick{\´y}, Milan and Markov{\´a}, Jana and R{\´o}zs{\´a}s, {\´A}rp{\´a}d}, title = {Assessment of compressive strength of historic masonry using non-destructive and destructive techniques}, series = {Construction and Building Materials}, volume = {193}, journal = {Construction and Building Materials}, number = {December}, publisher = {Elsevier}, doi = {10.1016/j.conbuildmat.2018.10.180}, pages = {196 -- 210}, abstract = {Masonry structures were built by various techniques using different materials, the properties of which exhibit a considerable scatter dependent on periods of construction and region-specific conditions. For historic structures with a heritage value, various non- or minor-destructive tests (NDTs) are commonly applied, while the application of destructive tests (DTs) is minimized. The contribution is based on investigations of 15 historic stone and clay brick masonry structures, for which NDT strengths of masonry units are verified by DTs. The proposed operational approach makes it possible to account for statistical uncertainty due to a limited number of DTs used to calibrate NDTs.}, language = {en} } @article{KasparRablMayer, author = {Kaspar, Marcel and Rabl, Hans-Peter and Mayer, Wolfgang}, title = {Ion-Molecule Reaction for the Selective Detection of Hydrocarbons in Diesel Exhaust Gas}, series = {Chemie Ingenieur Technik}, volume = {90}, journal = {Chemie Ingenieur Technik}, number = {6}, publisher = {WILEY-VCH}, doi = {10.1002/cite.201700075}, pages = {826 -- 834}, abstract = {The hydrocarbons present in the diesel exhaust gas are analyzed. A mass spectrometer is used for the measurements, and it operates on the basis of an ion-molecule reaction. This method is especially suitable because it is selective, is as free of fragments as possible, and is highly sensitive to the species that need to be measured. The study shows that numerous hydrocarbons in diesel exhaust gas can be identified. In particular, three molecules, ethyne, ethene and propene, were analyzed online in-depth on an engine test bench under different engine operating conditions.}, 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} } @article{daSilvaMotaHinckelRoccoetal., author = {da Silva Mota, Fabio Antonio and Hinckel, Jose Nivaldo and Rocco, Evandro Marconi and Schlingloff, Hanfried}, title = {Modeling and Analysis of a LOX/Ethanol Liquid Rocket Engine}, series = {Journal of Aerospace Technology and Management}, volume = {10}, journal = {Journal of Aerospace Technology and Management}, publisher = {Inst Aeronautica \& Espaco-IAE}, doi = {10.5028/jatm.v10.914}, abstract = {This work studies the performance and dry mass of the under development LOX/Ethanol L75 liquid rocket engine. To this end, an object-oriented program written in C++ was developed. The program is intended to be versatile and easily extensible in order to analyze different configurations of liquid rocket engines. The UML (Unified Modeling Language) tool is used to model the architecture of the codes. UML diagrams help to visualize the code structure and the communication between objects, enabling a high degree of abstraction. The cryogenics Vulcain and HM7B engines power cycles along with the staged-combustion SSME engine perform the verification of the codes. Finally, the influence of changes in design parameters on the performance and dry mass of the L75 rocket engine is analyzed.}, language = {en} } @article{BraunGebhardMatysiketal., author = {Braun, Peter and Gebhard, J{\"u}rgen and Matysik, Frank-Michael and Rabl, Hans-Peter}, title = {Potential Technical Approaches for Improving Low-Temperature NOx Conversion of Exhaust Aftertreatment Systems}, series = {Chemie Ingenieur Technik}, volume = {90}, journal = {Chemie Ingenieur Technik}, number = {6}, publisher = {WILEY-VCH}, doi = {10.1002/cite.201700122}, pages = {762 -- 773}, abstract = {Lean-burn engines, such as diesel engines, are widely used in mobile and stationary applications. Operation of lean-burn engines leads to formation of distinct amounts of nitrogen oxides (NO and NO2). Efficient aftertreatment is mandatory to meet legal requirements, especially at low exhaust temperatures, as for the future a decline of the exhaust temperature level can be predicted due to improved engine efficiencies. Within this review, potential technical solutions to enhance the DeNO(x)-aftertreatment efficiency at low exhaust temperatures are presented.}, language = {en} } @article{BarzSeligerMarxetal., author = {Barz, Tilman and Seliger, Dominik and Marx, Klemens and Sommer, Andreas and Walter, Sebastian F. and Bock, Hans Georg and Koerkel, Stefan}, title = {State and state of charge estimation for a latent heat storage}, series = {Control Engineering Practice}, volume = {72}, journal = {Control Engineering Practice}, publisher = {Pergamon-Elsevier d.}, doi = {10.1016/j.conengprac.2017.11.006}, pages = {151 -- 166}, abstract = {A nonlinear state observer is designed for a thermal energy storage with solid/liquid phase change material (PCM). Using a physical 2D dynamic model, the observer reconstructs transient spatial temperature fields inside the storage and estimates the stored energy and the state of charge. The observer has been successfully tested with a lab-scale latent heat storage with a single pass tube bundle and the phase change material located in a shell around each tube. It turns out that the observer robustly tracks the real process data with as few as four internal PCM temperature sensors. © 2017 Elsevier Ltd. All rights reserved.}, language = {en} } @article{daSilvaMotaHinckelRoccoetal., author = {da Silva Mota, Fabio Antonio and Hinckel, Jose Nivaldo and Rocco, Evandro Marconi and Schlingloff, Hanfried}, title = {Trajectory Optimization of Launch Vehicles Using Object-oriented Programming}, series = {Journal of aerospace technology and management}, volume = {10}, journal = {Journal of aerospace technology and management}, publisher = {Institute of Aeronautics and Space}, doi = {10.5028/jatm.v10.948}, abstract = {The aim of this study is to model launch vehicles with focus on 3-DOF trajectory optimization using a modular approach. Despite the large number of operational launch vehicles, they usually consist of basic components and subsystems. In other words, a launch vehicle is an assembly of stages, which in turn is divided into propellant system and engine, and the engine is an assembly of basic components such as pumps, turbines, combustion chamber, and nozzle. To allow future extension and reuse of the codes, a modular structure using object-oriented programming is used. Two formulations of state equations of the trajectory and two optimization methods are described. The launch vehicle performance will be measured by payload mass for a given mission. The simulations of the VLS-1, Ariane 5 and VLS-Alfa were performed and showed good agreement with the literature.}, language = {en} } @article{GaertnerRablZink, author = {G{\"a}rtner, Uwe and Rabl, Hans-Peter and Zink, Uwe}, title = {Exhaust Gas Aftertreatment of the Future}, series = {MTZ worldwide}, volume = {79}, journal = {MTZ worldwide}, number = {7-8}, publisher = {Springer}, doi = {10.1007/s38313-018-0060-2}, pages = {70 -- 75}, language = {en} } @article{SchuemannMorichKaufholdetal., author = {Sch{\"u}mann, Malte and Morich, J. and Kaufhold, Tobias 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{HacklHirschbergLexetal., author = {Hackl, Andreas and Hirschberg, Wolfgang and Lex, Cornelia 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} }