TY - JFULL ED - Engell, Lorenz ED - Siegert, Bernhard T1 - Schwerpunkt Synchronisation N2 - Nichts ist so aktuell wie die Gegenwart; gegenwärtig sein aber heißt gleichzeitig sein mit etwas anderem, und diese Gleichzeitigkeit muss immer eigens durch geeignete Operationen der Übertragung, der Überbrückung, der Abstimmung und ihre Werkzeuge hergestellt werden. So schlicht erklärt sich die grundlegende und aktuelle Relevanz des Themas der Synchronisierung ebenso wie seine kulturtechnische und medienphilosophische Ausformung. Die aktuelle medientheoretische und medienhistorische Aufmerksamkeit für die Verfertigung der Gegenwart (deren wichtigste Operation diejenige der Synchronisierung ist), wie sie sich auch im Jahresthema 2012/2013 der Forschungen am Internationalen Kolleg für Kulturtechnikforschung und Medienphilosophie (IKKM) niedergeschlagen hat, reagiert auf eine spezifische zeitphilosophische Spannungslage, die sich im Anschluss an die strukturale und poststrukturale sowie die systemtheoretische Differenztheorie einerseits und an eher empirische, phänomenale, aber auch technikhistorisch und -theoretisch relevante Sachverhalte andererseits ergeben hat. Den ersten Pol dieser Spannung bildet die Dekonstruktion der Präsenz, etwa, im Sinne Jacques Derridas, der Gleichzeitigkeit von Stimme und Ohr beim Sprechen, oder, im Sinne Deborah Eschs, der Live-Übertragung des Fernsehens. Den anderen Pol jedoch bilden die dennoch sich behauptenden phänomenalen und funktionalen Gleichzeitigkeitserfahrungen und -effekte. Sie umfassen etwa das Miterleben des Spielzuges im Sport, wie Hans Ulrich Gumbrecht es gefasst hat, und zahlreiche andere ästhetische, insbesondere erhabene Erfahrungen. Am anderen Ende der Skala gehören aber auch Prozesse wie die technische Einsteuerung und Abstimmung von Taktfrequenzen in Regelkreisen und Übertragungszusammenhängen zu den gültigen Formen effektiver Gleichzeitigkeit. Auch Verdichtungsvorgänge wie die mehr oder weniger instantane, ereignisbezogene wie ereignisförmige Bildung und Auflösung von Publika sind derlei relevante Präsenzeffekte. Die grundlegende Einsicht in die Gemachtheit und folglich Dekonstruierbarkeit der Gegenwart durch Synchronisierungs- und Desynchronisierungsoperationen jedenfalls widerstreitet nach medienwissenschaftlicher Überzeugung nicht ihrer Wirklichkeit im Sinne der Wirksamkeit – der lateinischen »actualitas«, als deren deutschsprachige Entsprechung die Scholastik des Mittelalters bei Meister Eckhart den Begriff der »Wirklichkeit« erst einführte. KW - Medienwissenschaft KW - Kulturwissenschaft Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20240507-48527 SN - 2366-0767 N1 - Lizenz CC-BY-NC-SA 3.0 VL - 2014 IS - 5.2014, Heft 2 PB - Felix Meiner Verlag CY - Hamburg ER - TY - JFULL ED - Engell, Lorenz ED - Siegert, Bernhard T1 - Focus Producing Places N2 - Producing places is a twofold topic. It can refer to places as sites that produce something, that are productive, that have operations unfold, or actions happen, or objects emerge. Or it can refer to the fabrication of places as specific entities themselves. With the extended availability and practicability of digital positioning, locating, and tracking systems, it has become evident that places are not just there, but that they are generated, that they are subject to mediatechnological operations and effects. Nonetheless, and at the same time, the aspect of places as being productive has also attracted considerable attention. Furthermore, in either perspective, a media-theoretical challenge has come up. It invests two different threads within the realm of conceptualizing not only space, but precisely place under conditions of media, both of them leading way back into the evolution of media societies and cultural technologies. KW - Medienwissenschaft KW - Kulturwissenschaft Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20240507-48519 SN - 2366-0767 N1 - Lizenz CC-BY-NC-SA 3.0 VL - 2014 IS - 5.2014, Heft 1 PB - Felix Meiner Verlag CY - Hamburg ER - TY - GEN A1 - Kleiner, Florian T1 - Charakterisierung des Einflusses der Wärmeleitfähigkeit von Kompositmaterialien auf die thermochemische Wärmespeicherung N2 - Mit dem stetigen Steigen des Anteils an erneuerbaren Energien wird der Einsatz von Speichern immer bedeutsamer. Neben der Speicherung elektrischer Energie ist die Speicherung anfallender solarer bzw. industrieller Wärme eine wichtige Herausforderung. Aufgrund der hohen Energiespeicherdichte kommt dabei der thermochemischen Wärmespeicherung eine entscheidende Rolle zu. Eine Klasse dieser Speichermaterialien bilden Kompositmaterialien, die aus einer offenporigen Matrix und einem darin eingelagerten Salzhydrat bestehen. Ausschlaggebend für eine hohe Speicherdichte ist bei dieser Materialklasse der schnelle Abtransport der durch Wasserdampfsorption entstandenen Wärme. Das entscheidende Kriterium für eine Anwendung als Speichermaterial ist somit die Wärmeleitfähigkeit des Materials. Im Rahmen der Arbeit wurden deshalb die Wärmeleitfähigkeiten ausgewählter Salze (NaCl, MgSO4 und ZnSO4) mit verschiedenen Kristallwassergehalten, Trägermaterialien wie Aktivkohle (Pellets und Pulver) und Zeolitpulver und an den daraus hergestellten Kompositmaterialien untersucht. Ziel war es außerdem Aussagen zu einer günstigen Materialkombination aus offenporigem Trägermaterial und Salzhydrat sowie eines geeigneten Porenfüllgrades zu treffen und Ansätze für die Modellierung der Wärmeleitfähigkeit der Komposite zu liefern. N2 - With the steady increase of renewable energies, the use of storage systems is becoming increasingly important. In addition to the storage of electrical energy, the storage of solar and industrial heat is an important challenge. Due to their high energy storage density, thermochemical heat storage materials are very promising. One class of these storage materials are composit materials, which consist of an porous matrix and an embedded salt hydrate. The decisive factor for a high storage density in this type of materials is the rapid removal of the heat generated by water vapor sorption. The decisive criterion for an application as a storage material is therefore the thermal conductivity of the material. The thermal conductivity of selected salts (NaCl, MgSO4 and ZnSO4) with different crystal water contents, carrier materials such as activated carbon (pellets and powder) and zeolite powder and the resulting composite materials were therefore investigated as part of the work. The aim was also to make statements on a favorable material combination of porous carrier material and salt hydrate as well as a suitable degree of pore filling and to provide approaches for modeling the thermal conductivity of the composites. KW - Wärmespeicher KW - Wärmeleitfähigkeit KW - Werkstoffkunde KW - Wärmespeicher KW - Wärmeleitfähigkeit KW - Hydratsalz KW - thermochemische Wärmespeicherung KW - thermochemical heat storage Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210921-44968 ER - TY - THES A1 - Habtemariam, Abinet Kifle T1 - Numerical Demolition Analysis of a Slender Guyed Antenna Mast N2 - The main purpose of the thesis is to ensure the safe demolition of old guyed antenna masts that are located in different parts of Germany. The major problem in demolition of this masts is the falling down of the masts in unexpected direction because of buckling problem. The objective of this thesis is development of a numerical models using finite element method (FEM) and assuring a controlled collapse by coming up with different time setups for the detonation of explosives which are responsible for cutting down the cables. The result of this thesis will avoid unexpected outcomes during the demolition processes and prevent risk of collapsing of the mast over near by structures. KW - Abbruch KW - Finite-Elemente-Methode KW - Optimierung KW - Demolition KW - Guyed antenna masts KW - Explicit finite element method KW - Optimization Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210723-44609 ER - TY - JOUR A1 - Chen, Zhen A1 - Schwing, Moritz A1 - Karlovšek, Jurij A1 - Wagner, Norman A1 - Scheuermann, Alexander T1 - Broadband Dielectric Measurement Methods for Soft Geomaterials: Coaxial Transmission Line Cell and Open-Ended Coaxial Probe JF - International Journal of Engineering and Technology N2 - Broadband dielectric measurement methods based on vector network analyzer coupled with coaxial transmission line cell (CC) and open-ended coaxial probe (OC) are simply reviewed, by which the dielectric behaviors in the frequency range of 1 MHz to 3 GHz of two practical geomaterials are investigated. Kaolin after modified compaction with different water contents is measured by using CC. The results are consistent with previous study on standardized compacted kaolin and suggest that the dielectric properties at frequencies below 100 MHz are not only a function of water content but also functions of other soil state parameters including dry density. The hydration process of a commercial grout is monitored in real time by using OC. It is found that the time dependent dielectric properties can accurately reveal the different stages of the hydration process. These measurement results demonstrate the practicability of the introduced methods in determining dielectric properties of soft geomaterials. KW - Impedanzspektroskopie KW - Electromagnetic properties of porous materials KW - Koaxialkabel KW - Dielectric spectroscopy KW - open-ended coaxial probe KW - coaxial transmission line KW - real-time monitoring KW - physicochemical properties of geomaterials Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210408-43984 UR - http://www.ijetch.org/index.php?m=content&c=index&a=show&catid=58&id=838 VL - 2014 IS - volume 6, number 5 SP - 373 EP - 380 ER - TY - THES A1 - Kavrakov, Igor T1 - Structural Optimization of Composite Cross-Sections and Elements using Energy Methods N2 - Structural optimization has gained considerable attention in the design of structural engineering structures, especially in the preliminary phase. This study introduces an unconventional approach for structural optimization by utilizing the Energy method with Integral Material Behavior (EIM), based on the Lagrange’s principle of minimum potential energy. An automated two-level optimization search process is proposed, which integrates the EIM, as an alternative method for nonlinear structural analysis, and the bilevel optimization. The proposed procedure secures the equilibrium through minimizing the potential energy on one level, and on a higher level, a design objective function. For this, the most robust strategy of bilevel optimization, the nested method is used. The function of the potential energy is investigated along with its instabilities for physical nonlinear analysis through principle examples, by which the advantages and limitations using this method are reviewed. Furthermore, optimization algorithms are discussed. A numerical fully functional code is developed for nonlinear cross section, element and 2D frame analysis, utilizing different finite elements and is verified against existing EIM programs. As a proof of concept, the method is applied on selected examples using this code on cross section and element level. For the former one a comparison is made with standard procedure, by employing the equilibrium equations within the constrains. The validation of the element level was proven by a theoretical solution of an arch bridge and finally, a truss bridge is optimized. Most of the principle examples are chosen to be adequate for the everyday engineering practice, to demonstrate the effectiveness of the proposed method. This study implies that with further development, this method could become just as competitive as the conventional structural optimization techniques using the Finite Element Method. KW - Strukturoptimierung Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20190815-39593 ER - TY - JOUR A1 - Völker, Conrad A1 - Mämpel, Silvio A1 - Kornadt, Oliver T1 - Measuring the human body’s micro‐climate using a thermal manikin JF - Indoor Air N2 - The human body is surrounded by a micro‐climate which results from its convective release of heat. In this study, the air temperature and flow velocity of this micro‐climate were measured in a climate chamber at various room temperatures, using a thermal manikin simulating the heat release of the human being. Different techniques (Particle Streak Tracking, thermography, anemometry, and thermistors) were used for measurement and visualization. The manikin surface temperature was adjusted to the particular indoor climate based on simulations with a thermoregulation model (UCBerkeley Thermal Comfort Model). We found that generally, the micro‐climate is thinner at the lower part of the torso, but expands going up. At the head, there is a relatively thick thermal layer, which results in an ascending plume above the head. However, the micro‐climate shape strongly depends not only on the body segment, but also on boundary conditions: the higher the temperature difference between the surface temperature of the manikin and the air temperature, the faster the air flow in the micro‐climate. Finally, convective heat transfer coefficients strongly increase with falling room temperature, while radiative heat transfer coefficients decrease. The type of body segment strongly influences the convective heat transfer coefficient, while only minimally influencing the radiative heat transfer coefficient. KW - Raumklima KW - Mikroklima KW - Wärmeübertragung KW - Strömungsmechanik KW - thermal manikin KW - climate chamber KW - micro climate KW - heat transfer coefficient KW - CFD KW - thermography Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20181025-38153 UR - https://onlinelibrary.wiley.com/doi/abs/10.1111/ina.12112 N1 - This is the peer reviewed version of the following article: "Measuring the human body’s micro‐climate using a thermal manikin", which has been published in final form at https://doi.org/10.1111/ina.12112. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. IS - 24, 6 SP - 567 EP - 579 ER - TY - JOUR A1 - Zhuang, Xiaoying A1 - Huang, Runqiu A1 - Rabczuk, Timon A1 - Liang, C. T1 - A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage JF - Mathematical Problems in Engineering N2 - A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Amiri, Fatemeh A1 - Millán, D. A1 - Shen, Y. A1 - Rabczuk, Timon A1 - Arroyo, M. T1 - Phase-field modeling of fracture in linear thin shells JF - Theoretical and Applied Fracture Mechanics N2 - Phase-field modeling of fracture in linear thin shells KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 102 EP - 109 ER - TY - JOUR A1 - Thai, Chien H. A1 - Ferreira, A.J.M. A1 - Bordas, Stéphane Pierre Alain A1 - Rabczuk, Timon A1 - Nguyen-Xuan, Hung T1 - Isogeometric analysis of laminated composite and sandwich plates using a new inverse trigonometric shear deformation theory JF - European Journal of Mechanics N2 - Isogeometric analysis of laminated composite and sandwich plates using a new inverse trigonometric shear deformation theory KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 89 EP - 108 ER - TY - JOUR A1 - Nanthakumar, S.S. A1 - Lahmer, Tom A1 - Rabczuk, Timon T1 - Detection of multiple flaws in piezoelectric structures using XFEM and level sets JF - Computer Methods in Applied Mechanics and Engineering N2 - Detection of multiple flaws in piezoelectric structures using XFEM and level sets KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2014 SP - 98 EP - 112 ER - TY - JOUR A1 - Chen, Lei A1 - Nguyen-Thanh, Nhon A1 - Nguyen-Xuan, Hung A1 - Rabczuk, Timon A1 - Bordas, Stéphane Pierre Alain A1 - Limbert, Georges T1 - Explicit finite deformation analysis of isogeometric membranes JF - Computer Methods in Applied Mechanics and Engineering N2 - Explicit finite deformation analysis of isogeometric membranes KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 104 EP - 130 ER - TY - JOUR A1 - Vu-Bac, N. A1 - Lahmer, Tom A1 - Keitel, Holger A1 - Zhao, Jun-Hua A1 - Zhuang, Xiaoying A1 - Rabczuk, Timon T1 - Stochastic predictions of bulk properties of amorphous polyethylene based on molecular dynamics simulations JF - Mechanics of Materials N2 - Stochastic predictions of bulk properties of amorphous polyethylene based on molecular dynamics simulations KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2014 SP - 70 EP - 84 ER - TY - JOUR A1 - Ghasemi, Hamid A1 - Rafiee, Roham A1 - Zhuang, Xiaoying A1 - Muthu, Jacob A1 - Rabczuk, Timon T1 - Uncertainties propagation in metamodel-based probabilistic optimization of CNT/polymer composite structure using stochastic multi-scale modeling JF - Computational Materials Science N2 - Uncertainties propagation in metamodel-based probabilistic optimization of CNT/polymer composite structure using stochastic multi-scale modeling KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 295 EP - 305 ER - TY - JOUR A1 - Ghasemi, Hamid A1 - Brighenti, Roberto A1 - Zhuang, Xiaoying A1 - Muthu, Jacob A1 - Rabczuk, Timon T1 - Optimization of fiber distribution in fiber reinforced composite by using NURBS functions JF - Computational Materials Science N2 - Optimization of fiber distribution in fiber reinforced composite by using NURBS functions KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 463 EP - 473 ER - TY - JOUR A1 - Jiang, Jin-Wu A1 - Park, Harold S. A1 - Rabczuk, Timon T1 - MoS2 nanoresonators: intrinsically better than graphene? JF - Nanoscale N2 - MoS2 nanoresonators: intrinsically better than graphene? KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 3618 EP - 3625 ER - TY - JOUR A1 - Luu, M. A1 - Martinez-Rodrigo, M.D. A1 - Zabel, Volkmar A1 - Könke, Carsten T1 - H∞ optimization of fluid viscous dampers for reducing vibrations of high-speed railway bridges JF - Journal of Sound and Vibration N2 - H∞ optimization of fluid viscous dampers for reducing vibrations of high-speed railway bridges KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 2421 EP - 2442 ER - TY - JOUR A1 - Nguyen-Thanh, Nhon A1 - Muthu, Jacob A1 - Zhuang, Xiaoying A1 - Rabczuk, Timon T1 - An adaptive three-dimensional RHT-splines formulation in linear elasto-statics and elasto-dynamics JF - Computational Mechanics N2 - An adaptive three-dimensional RHT-splines formulation in linear elasto-statics and elasto-dynamics KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 369 EP - 385 ER - TY - JOUR A1 - Amani, Jafar A1 - Bagherzadeh, Amir Saboor A1 - Rabczuk, Timon T1 - Error estimate and adaptive refinement in Mixed Discrete Least Squares Meshless method JF - Mathematical Problems in Engineering N2 - Error estimate and adaptive refinement in Mixed Discrete Least Squares Meshless method KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Budarapu, Pattabhi Ramaiah A1 - Gracie, Robert A1 - Yang, Shih-Wei A1 - Zhuang, Xiaoying A1 - Rabczuk, Timon T1 - Efficient Coarse Graining in Multiscale Modeling of Fracture JF - Theoretical and Applied Fracture Mechanics N2 - Efficient Coarse Graining in Multiscale Modeling of Fracture KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 126 EP - 143 ER - TY - JOUR A1 - Nguyen-Thoi, T. A1 - Rabczuk, Timon A1 - Lam-Phat, T. A1 - Ho-Huu, V. A1 - Phung-Van, P. T1 - Free vibration analysis of cracked Mindlin plate using an extended cell-based smoothed discrete shear gap method (XCS-DSG3) JF - Theoretical and Applied Fracture Mechanics N2 - Free vibration analysis of cracked Mindlin plate using an extended cell-based smoothed discrete shear gap method (XCS-DSG3) KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Jamshidian, M. A1 - Rabczuk, Timon T1 - Phase field modelling of stressed grain growth: Analytical study and the effect of microstructural length scale JF - Journal of Computational Physics N2 - Phase field modelling of stressed grain growth: Analytical study and the effect of microstructural length scale KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 23 EP - 35 ER - TY - JOUR A1 - Vu-Bac, N. A1 - Lahmer, Tom A1 - Zhang, Yancheng A1 - Zhuang, Xiaoying A1 - Rabczuk, Timon T1 - Stochastic predictions of interfacial characteristic of polymeric nanocomposites (PNCs) JF - Composites Part B Engineering N2 - Stochastic predictions of interfacial characteristic of polymeric nanocomposites (PNCs) KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2014 SP - 80 EP - 95 ER - TY - JOUR A1 - Jiang, Jin-Wu A1 - Wang, Bing-Shen A1 - Rabczuk, Timon T1 - Phonon modes in single-walled molybdenum disulphide nanotubes: lattice dynamics calculation and molecular dynamics simulation JF - Nanotechnology N2 - Phonon modes in single-walled molybdenum disulphide nanotubes: lattice dynamics calculation and molecular dynamics simulation KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Zhang, Yancheng A1 - Zhuang, Xiaoying A1 - Muthu, Jacob A1 - Mabrouki, Tarek A1 - Fontaine, Michaël A1 - Gong, Yadong A1 - Rabczuk, Timon T1 - Load transfer of graphene/carbon nanotube/polyethylene hybrid nanocomposite by molecular dynamics simulation JF - Composites Part B Engineering N2 - Load transfer of graphene/carbon nanotube/polyethylene hybrid nanocomposite by molecular dynamics simulation KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 27 EP - 33 ER - TY - JOUR A1 - Areias, Pedro A1 - Pinto da Costa, A. A1 - Rabczuk, Timon A1 - Queiros de Melo, F. J. M. A1 - Dias-da-Costa, D. T1 - An alternative formulation for quasi-static frictional and cohesive contact problems JF - Computational Mechanics N2 - An alternative formulation for quasi-static frictional and cohesive contact problems KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 807 EP - 824 ER - TY - JOUR A1 - Talebi, Hossein A1 - Silani, Mohammad A1 - Bordas, Stéphane Pierre Alain A1 - Kerfriden, Pierre A1 - Rabczuk, Timon T1 - A computational library for multiscale modeling of material failure JF - Computational Mechanics N2 - A computational library for multiscale modeling of material failure KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Zhao, Jun-Hua A1 - Lu, Lixin A1 - Rabczuk, Timon T1 - Binding energy and mechanical stability of single- and multi-walled carbon nanotube serpentines JF - The Journal of Chemical Physics N2 - Binding energy and mechanical stability of single- and multi-walled carbon nanotube serpentines KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 U6 - http://dx.doi.org/10.1063/1.4878115 ER - TY - JOUR A1 - Budarapu, Pattabhi Ramaiah A1 - Gracie, Robert A1 - Bordas, Stéphane Pierre Alain A1 - Rabczuk, Timon T1 - An adaptive multiscale method for quasi-static crack growth JF - Computational Mechanics N2 - This paper proposes an adaptive atomistic- continuum numerical method for quasi-static crack growth. The phantom node method is used to model the crack in the continuum region and a molecular statics model is used near the crack tip. To ensure self-consistency in the bulk, a virtual atom cluster is used to model the material of the coarse scale. The coupling between the coarse scale and fine scale is realized through ghost atoms. The ghost atom positions are interpolated from the coarse scale solution and enforced as boundary conditions on the fine scale. The fine scale region is adaptively enlarged as the crack propagates and the region behind the crack tip is adaptively coarsened. An energy criterion is used to detect the crack tip location. The triangular lattice in the fine scale region corresponds to the lattice structure of the (111) plane of an FCC crystal. The Lennard-Jones potential is used to model the atom–atom interactions. The method is implemented in two dimensions. The results are compared to pure atomistic simulations; they show excellent agreement. KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 U6 - http://dx.doi.org/10.1007/s00466-013-0952-6 SP - 1129 EP - 1148 ER - TY - JOUR A1 - Nguyen-Xuan, Hung A1 - Nguyen, Hiep Vinh A1 - Bordas, Stéphane Pierre Alain A1 - Rabczuk, Timon A1 - Duflot, Marc T1 - A cell-based smoothed finite element method for three dimensional solid structures JF - KSCE Journal of Civil Engineering N2 - This paper extends further the strain smoothing technique in finite elements to 8-noded hexahedral elements (CS-FEM-H8). The idea behind the present method is similar to the cell-based smoothed 4-noded quadrilateral finite elements (CS-FEM-Q4). In CSFEM, the smoothing domains are created based on elements, and each element can be further subdivided into 1 or several smoothing cells. It is observed that: 1) The CS-FEM using a single smoothing cell can produce higher stress accuracy, but insufficient rank and poor displacement accuracy; 2) The CS-FEM using several smoothing cells has proper rank, good displacement accuracy, but lower stress accuracy, especially for nearly incompressible and bending dominant problems. We therefore propose 1) an extension of strain smoothing to 8-noded hexahedral elements and 2) an alternative CS-FEM form, which associates the single smoothing cell issue with multi-smoothing cell one via a stabilization technique. Several numerical examples are provided to show the reliability and accuracy of the present formulation. KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 U6 - http://dx.doi.org/10.1007/s12205-012-1515-7 SP - 1230 EP - 1242 ER - TY - JOUR A1 - Joshi, Suraj A1 - Hildebrand, Jörg A1 - Aloraier, Abdulkareem S. A1 - Rabczuk, Timon T1 - Characterization of material properties and heat source parameters in welding simulation of two overlapping beads on a substrate plate JF - Computational Materials Science N2 - This paper presents several aspects of characterization of welding heat source parameters in Goldak’s double ellipsoidal model using Sysweld simulation of welding of two overlapping beads on a substrate steel plate. The overlap percentages ranged from 40% to 80% in increments of 10%. The new material properties of the fused metal were characterized using Weldware and their continuous cooling transformation curves. The convective and radiative heat transfer coefficients as well as the cooling time t8/5 were estimated using numerical formulations from relevant standards. The effects of the simulation geometry and mesh discretization were evaluated in terms of the factor F provided in Sysweld. Eventually, the parameters of Goldak’s double ellipsoidal heat source model were determined for the welding simulation of overlapping beads on the plate and the simulated bead geometry, extent of the molten pool and the HAZ were compared with the macrographs of cross-sections of the experimental weldments. The results showed excellent matching, thus verifying this methodology for determination of welding heat source parameters. KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 U6 - http://dx.doi.org/10.1016/j.commatsci.2012.11.029 SP - 559 EP - 565 ER - TY - JOUR A1 - Zhao, Jun-Hua A1 - Jiang, Jin-Wu A1 - Jia, Yue A1 - Guo, Wanlin A1 - Rabczuk, Timon T1 - A theoretical analysis of cohesive energy between carbon nanotubes, graphene and substrates JF - Carbon N2 - Explicit solutions for the cohesive energy between carbon nanotubes, graphene and substrates are obtained through continuum modeling of the van der Waals interaction between them. The dependence of the cohesive energy on their size, spacing and crossing angles is analyzed. Checking against full atom molecular dynamics calculations and available experimental results shows that the continuum solution has high accuracy. The equilibrium distances between the nanotubes, graphene and substrates with minimum cohesive energy are also provided explicitly. The obtained analytical solution should be of great help for understanding the interaction between the nanostructures and substrates, and designing composites and nanoelectromechanical systems. KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 U6 - http://dx.doi.org/10.1016/j.carbon.2013.01.041 SP - 108 EP - 119 ER - TY - JOUR A1 - Areias, Pedro A1 - Rabczuk, Timon A1 - Barbosa, J.I. T1 - The extended unsymmetric frontal solution for multiple-point constraints JF - Engineering Computations N2 - The extended unsymmetric frontal solution for multiple-point constraints KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Zhao, Jiyun A1 - Jiang, Jin-Wu A1 - Wang, L. A1 - Guo, Wanlin A1 - Rabczuk, Timon T1 - Coarse-grained potentials of single-walled carbon nanotubes JF - Journal of the Mechanics and Physics of Solids N2 - Coarse-grained potentials of single-walled carbon nanotubes KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Beex, L.A.A. A1 - Kerfriden, Pierre A1 - Rabczuk, Timon A1 - Bordas, Stéphane Pierre Alain T1 - Quasicontinuum-based multiscale approaches for plate-like beam lattices experiencing in-plane and out-of-plane deformation JF - Computer Methods in Applied Mechanics and Engineering N2 - Quasicontinuum-based multiscale approaches for plate-like beam lattices experiencing in-plane and out-of-plane deformation KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Areias, Pedro A1 - Rabczuk, Timon A1 - Camanho, P.P. T1 - Finite strain fracture of 2D problems with injected anisotropic softening elements JF - Theoretical and Applied Fracture Mechanics N2 - Finite strain fracture of 2D problems with injected anisotropic softening elements KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Jia, Yue A1 - Anitescu, Cosmin A1 - Ghorashi, Seyed Shahram A1 - Rabczuk, Timon A1 - Dias-da-Costa, D. T1 - Extended Isogeometric Analysis for Material Interface Problems JF - Journal of Applied Mathematics N2 - Extended Isogeometric Analysis for Material Interface Problems KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Xu, G. A1 - Mourrain, B. A1 - Galligo, A. A1 - Rabczuk, Timon T1 - High-quality construction of analysis-suitable trivariate NURBS solids by reparameterization methods JF - Computational Mechanics N2 - High-quality construction of analysis-suitable trivariate NURBS solids by reparameterization methods KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Nguyen, V.P. A1 - Kerfriden, Pierre A1 - Bordas, Stéphane Pierre Alain A1 - Rabczuk, Timon T1 - Isogeometric analysis suitable trivariate NURBS representation of composite panels with a new offset algorithm JF - Computer-Aided Design N2 - Isogeometric analysis suitable trivariate NURBS representation of composite panels with a new offset algorithm KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Silani, Mohammad A1 - Ziaei-Rad, S. A1 - Talebi, Hossein A1 - Rabczuk, Timon T1 - A Semi-Concurrent Multiscale Approach for Modeling Damage in Nanocomposites JF - Theoretical and Applied Fracture Mechanics N2 - A Semi-Concurrent Multiscale Approach for Modeling Damage in Nanocomposites KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Zhao, Jun-Hua A1 - Kou, Liangzhi A1 - Jiang, Jin-Wu A1 - Rabczuk, Timon T1 - Tension-induced phase transition of single-layer molybdenum disulphide (MoS2) at low temperatures JF - Nanotechnology N2 - Tension-induced phase transition of single-layer molybdenum disulphide (MoS2) at low temperatures KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 U6 - http://dx.doi.org/10.1088/0957-4484/25/29/295701 ER - TY - JOUR A1 - Ghasemi, Hamid A1 - Brighenti, Roberto A1 - Zhuang, Xiaoying A1 - Muthu, Jacob A1 - Rabczuk, Timon T1 - Sequential reliability based optimization of fiber content and dispersion in fiber reinforced composite by using NURBS finite elements JF - Structural and Multidisciplinary Optimization N2 - Sequential reliability based optimization of fiber content and dispersion in fiber reinforced composite by using NURBS finite elements KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Ilyani Akmar, A.B. A1 - Lahmer, Tom A1 - Bordas, Stéphane Pierre Alain A1 - Beex, L.A.A. A1 - Rabczuk, Timon T1 - Uncertainty quantification of dry woven fabrics: A sensitivity analysis on material properties JF - Composite Structures N2 - Uncertainty quantification of dry woven fabrics: A sensitivity analysis on material properties KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2014 U6 - http://dx.doi.org/10.1016/j.compstruct.2014.04.014 SP - 1 EP - 17 ER - TY - JOUR A1 - Massaretti, Pier Giorgio T1 - Dagli inizi dell’urbanismo teorico alla città moderna. Visioni urbanistiche del totalitarismo – Italia JF - Anthologie zum Städtebau. Das Phänomen Großstadt und die Entstehung der Stadt der Moderne N2 - La prima edizione di questo testo è apparsa, in tedesco, nel volume II.2.: Anthologie zum Städtebau. Das Phänomen Großstadt und die Entstehung der Stadt der Moderne, a cura di Vittorio Magnago Lampugnani, Katia Frey, Eliana Perotti, con il sostegno di Departement Architektur der Eidgenössischen Technischen Hochschule, Zürich (Gebr. Mann Verlag, Berlin 2014, pp. 1307-1390). Previ specifici accordi con l’editore, viene qui presentata la versione originaria, in italiano, dell’intero capitolo: Modernität und Emphase. Städtebau im italienischen Faschismus, e comprendente: i) una capiente saggio introduttivo – in una versione più ampia ed articolata (comprensiva della “Bibliografia sistematica”, di riferimento) del testo in tedesco; ii) la versione in italiano del repertorio antologico di riferimento – e comprensiva di una “Scheda introduttiva”, sull’Autore-Opera, e di una selezione del testo in esame. KW - Städtebau Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170529-32228 SP - 1 EP - 45 ER - TY - CHAP A1 - Massaretti, Pier Giorgio T1 - La ri-fondazione della Libia balbiana (1933-1939). Il poderoso racconto fotografico dei “Ventimila” T2 - Città mediterranee in trasformazione N2 - La prima edizione di questo testo è apparsa negli atti del VI Convegno Internazionale di Studi del CIRICE – Centro Interdipartimentale di Ricerca sull’Iconografia della Città Europea − Università di Napoli Federico II, (Napoli, 13-15 marzo 2014), dal titolo: Città mediterranee in trasformazione. Identità e immagine del paesaggio urbano tra Sette e Novecento, a cura di A. Buccaro e C. de Seta (Collana: Polis, 6; Napoli: Edizioni Scientifiche Italiane, 2014; pp. 1216; ISBN 9788849528145), all’interno della sessione 7, Le trasformazioni del paesaggio urbano nella fotografia e nella cinematografia, coordinatori: F. Capano, M. Iuliano, pp. 1085-1098. Il Convegno, aperto a studiosi di ambito nazionale e internazionale, si poneva l’obiettivo di fare il punto sulla storiografia riguardante la città mediterranea in età contemporanea, con particolare riferimento alla sua identità, struttura e immagine, dall’inizio dell’industrializzazione all’età post-illuminista e borghese, fino ai temi inerenti l’evoluzione/involuzione del territorio e del paesaggio post-industriale, nonché lo sviluppo del modello turistico tra Otto e Novecento. KW - Städtebau Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170529-32234 ER - TY - JOUR A1 - Zhuang, Xiaoying A1 - Huang, Runqiu A1 - Liang, Chao A1 - Rabczuk, Timon T1 - A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage JF - Mathematical Problems in Engineering N2 - Renewable energy resources such as wind and solar are intermittent, which causes instability when being connected to utility grid of electricity. Compressed air energy storage (CAES) provides an economic and technical viable solution to this problem by utilizing subsurface rock cavern to store the electricity generated by renewable energy in the form of compressed air. Though CAES has been used for over three decades, it is only restricted to salt rock or aquifers for air tightness reason. In this paper, the technical feasibility of utilizing hard rock for CAES is investigated by using a coupled thermo-hydro-mechanical (THM) modelling of nonisothermal gas flow. Governing equations are derived from the rules of energy balance, mass balance, and static equilibrium. Cyclic volumetric mass source and heat source models are applied to simulate the gas injection and production. Evaluation is carried out for intact rock and rock with discrete crack, respectively. In both cases, the heat and pressure losses using air mass control and supplementary air injection are compared. KW - Energiespeicherung KW - Druckluft KW - Kaverne KW - Modellierung Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170428-31726 ER - TY - JOUR A1 - Völske, Michael A1 - Gollub, Tim A1 - Hagen, Matthias A1 - Stein, Benno T1 - A keyquery-based classification system for CORE JF - D-Lib Magazine N2 - We apply keyquery-based taxonomy composition to compute a classification system for the CORE dataset, a shared crawl of about 850,000 scientific papers. Keyquery-based taxonomy composition can be understood as a two-phase hierarchical document clustering technique that utilizes search queries as cluster labels: In a first phase, the document collection is indexed by a reference search engine, and the documents are tagged with the search queries they are relevant—for their so-called keyqueries. In a second phase, a hierarchical clustering is formed from the keyqueries within an iterative process. We use the explicit topic model ESA as document retrieval model in order to index the CORE dataset in the reference search engine. Under the ESA retrieval model, documents are represented as vectors of similarities to Wikipedia articles; a methodology proven to be advantageous for text categorization tasks. Our paper presents the generated taxonomy and reports on quantitative properties such as document coverage and processing requirements. KW - Massendaten KW - Taxonomie KW - Dynamic Taxonomy Composition, Keyquery, Classification Systems, Reverted Index, Big Data Problem Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170426-31662 ER - TY - JOUR A1 - Nagel, Falk A1 - Simon, Flaviu A1 - Kümmel, Benjamin A1 - Bergmann, Jean Pierre A1 - Hildebrand, Jörg T1 - Optimization Strategies for Laser Welding High Alloy Steel Sheets JF - Physics Procedia N2 - A known phenomenon during laser welding of thin sheets is the deformation caused by thermally induced stresses. This deformation can result in a change of the gap width between the welded parts, which leads to an unstable welding process. Inducing displacements by using a second heat source will compensate for the change in gap width, hence optimizing the welding process. The base material is 1 mm thick austenitic stainless steel 1.4301, which is welded by a CO2 laser. The second heat source is a diode laser. The gap between the welded parts was set between 0.05 mm and 0.1 mm. The influence of the second heat source on the welding process and the welding result is described. The usage of a second heat source allows a higher gap width to be set prior to the welding process. The results of the numerical simulation were found to be corresponding to those of the experiments. KW - Edelstahl KW - Laserschweißen KW - Laser Welding; CO2; Diode; Distortion; Finite Element Analysis; Thermal Analysis; Mechanical Analysis; Numerical Model Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170425-31554 SP - 1242 EP - 1251 ER - TY - JOUR A1 - Motra, Hem Bahadur A1 - Hildebrand, Jörg A1 - Dimmig-Osburg, Andrea T1 - Assessment of strain measurement techniques to characterise mechanical properties of structural steel JF - Engineering Science and Technology, an International Journal N2 - Strain measurement is important in mechanical testing. A wide variety of techniques exists for measuring strain in the tensile test; namely the strain gauge, extensometer, stress and strain determined by machine crosshead motion, Geometric Moire technique, optical strain measurement techniques and others. Each technique has its own advantages and disadvantages. The purpose of this study is to quantitatively compare the strain measurement techniques. To carry out the tensile test experiments for S 235, sixty samples were cut from the web of the I-profile in longitudinal and transverse directions in four different dimensions. The geometry of samples are analysed by 3D scanner and vernier caliper. In addition, the strain values were determined by using strain gauge, extensometer and machine crosshead motion. Three techniques of strain measurement are compared in quantitative manner based on the calculation of mechanical properties (modulus of elasticity, yield strength, tensile strength, percentage elongation at maximum force) of structural steel. A statistical information was used for evaluating the results. It is seen that the extensometer and strain gauge provided reliable data, however the extensometer offers several advantages over the strain gauge and crosshead motion for testing structural steel in tension. Furthermore, estimation of measurement uncertainty is presented for the basic material parameters extracted through strain measurement. KW - Baustahl KW - Werkstoffprüfung KW - Zugversuch KW - Affecting factors; Measurement uncertainty; Materials testing; Quantitative comparison; Strain comparison; Tensile test Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170425-31540 SP - 260 EP - 269 ER - TY - JOUR A1 - Masood, R. A1 - Kharal, M. K. N. A1 - Nasir, A.R. T1 - Is BIM Adoption Advantageous for Construction Industry of Pakistan? JF - Procedia Engineering N2 - Lack of Information technology applications on construction projects lead to complex flow of data during project life cycle. Building Information Modeling (BIM) has gained attention in the Architectural, Engineering and Construction (AEC) industry, envisage the use of virtual n-dimensional (n-D) models to identify potential conflicts in design, construction or operational of any facility. A questionnaire has been designed to investigate perceptions regarding BIM advantages. Around 102 valid responses received from diversified stakeholders. Results showed very low BIM adoption with low level of ‘Buzz’. BIM is a faster and more effective method for designing and construction management, it improves quality of the design and construction and reduces rework during construction; which came out as the top thee advantages according to the perception of AEC professionals of Pakistan.BIM has least impact on reduction of cost, time and human resources. This research is a bench mark study to understand adoption and advantageous of BIM in Pakistan Construction Industry. KW - Building Information Modeling KW - Bauindustrie KW - Pakistan KW - BIM, BIM Adoption, BIM Advantages , Construction Industry, Pakistan Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170425-31509 SP - 229 EP - 238 ER -