Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-2779 Konferenzveröffentlichung Morais, Joao; Georgiev, Svetlin; Sprößig, Wolfgang Gürlebeck, Klaus; Lahmer, Tom; Werner, Frank A NOTE ON THE CLIFFORD FOURIER-STIELTJES TRANSFORM The purpose of this article is to provide an overview of the real Clifford Fourier- Stieltjes transform (CFST) and of its important properties. Additionally, we introduce the definition of convolution of Clifford functions of bounded variation. 13 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27794 10.25643/bauhaus-universitaet.2779 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-3385 Wissenschaftlicher Artikel Talebi, Hossein; Zi, Goangseup; Silani, Mohammad; Samaniego, Esteban; Rabczuk, Timon A simple circular cell method for multilevel finite element analysis A simple multiscale analysis framework for heterogeneous solids based on a computational homogenization technique is presented. The macroscopic strain is linked kinematically to the boundary displacement of a circular or spherical representative volume which contains the microscopic information of the material. The macroscopic stress is obtained from the energy principle between the macroscopic scale and the microscopic scale. This new method is applied to several standard examples to show its accuracy and consistency of the method proposed. Journal of Applied Mathematics 10.1155/2012/526846 Institut für Strukturmechanik (ISM) OPUS4-3163 Wissenschaftlicher Artikel Talebi, Hossein; Zi, Goangseup; Silani, Mohammad; Samaniego, Esteban; Rabczuk, Timon A simple circular cell method for multilevel finite element analysis A simple multiscale analysis framework for heterogeneous solids based on a computational homogenization technique is presented. The macroscopic strain is linked kinematically to the boundary displacement of a circular or spherical representative volume which contains the microscopic information of the material. The macroscopic stress is obtained from the energy principle between the macroscopic scale and the microscopic scale. This new method is applied to several standard examples to show its accuracy and consistency of the method proposed. Journal of Applied Mathematics urn:nbn:de:gbv:wim2-20170426-31639 10.1155/2012/526846 Institut für Strukturmechanik (ISM) OPUS4-3386 Wissenschaftlicher Artikel Jiang, Jin-Wu; Wang, Bing-Shen; Rabczuk, Timon Acoustic and breathing phonon modes in bilayer graphene with Moire-acute patterns The lattice dynamics properties are investigated for twisting bilayer graphene. There are big jumps for the inter-layer potential at twisting angle θ=0° and 60°, implying the stability of Bernal-stacking and the instability of AA-stacking structures, while a long platform in [8,55]° indicates the ease of twisting bilayer graphene in this wide angle range. Significant frequency shifts are observed for the z breathing mode around θ=0° and 60°, while the frequency is a constant in a wide range [8,55]°. Using the z breathing mode, a mechanical nanoresonator is proposed to operate on a robust resonant frequency in terahertz range. Applied Physics Letters 10.1063/1.4735246 Institut für Strukturmechanik (ISM) OPUS4-3137 Wissenschaftlicher Artikel Hildebrand, Jörg; Hecht, Kerstin; Bliedtner, Jens; Müller, Hartmut Advanced Analysis of Laser Beam Polishing of Quartz Glass Surfaces The laser beam is a small, flexible and fast polishing tool. With laser radiation it is possible to finish many outlines or geometries on quartz glass surfaces in the shortest possible time. It's a fact that the temperature developing while polishing determines the reachable surface smoothing and, as a negative result, causes material tensions. To find out which parameters are important for the laser polishing process and the surface roughness respectively and to estimate material tensions, temperature simulations and extensive polishing experiments took place. During these experiments starting and machining parameters were changed and temperatures were measured contact-free. The accuracy of thermal and mechanical simulation was improved in the case of advanced FE-analysis. 8 Physics Procedia 277 285 urn:nbn:de:gbv:wim2-20170418-31372 10.1016/j.phpro.2012.10.039 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2672 Wissenschaftlicher Artikel Köhler, Hermann; König, Reinhard Aktionsräume in Dresden In vorliegender Studie werden die Aktionsräume von Befragten in Dresden über eine standardisierte Befragung (n=360) untersucht. Die den Aktionsräumen zugrundeliegenden Aktivitäten werden unterschieden in Einkaufen für den täglichen Bedarf, Ausgehen (z.B. in Café, Kneipe, Gaststätte), Erholung im Freien (z.B. spazieren gehen, Nutzung von Grünanlagen) und private Geselligkeit (z.B. Feiern, Besuch von Verwandten/Freunden). Der Aktionsradius wird unterschieden in Wohnviertel, Nachbarviertel und sonstiges weiteres Stadtgebiet. Um aus den vier betrachteten Aktivitäten einen umfassenden Kennwert für den durchschnittlichen Aktionsradius eines Befragten zu bilden, wird ein Modell für den Kennwert eines Aktionsradius entwickelt. Die Studie kommt zu dem Ergebnis, dass das Alter der Befragten einen signifikanten - wenn auch geringen - Einfluss auf den Aktionsradius hat. Das Haushaltsnettoeinkommen hat einen mit Einschränkung signifikanten, ebenfalls geringen Einfluss auf alltägliche Aktivitäten der Befragten. urn:nbn:de:gbv:wim2-20160822-26726 10.25643/bauhaus-universitaet.2672 Professur Informatik in der Architektur OPUS4-1569 Buch (Monographie) Maier, Matthias; Simon-Ritz, Frank Alles digital? E-Books in Studium und Forschung : Weimarer EDOC-Tage 2011 Es ist ein Bild aus alten Tagen: ein wissbegieriger Student, auf der Suche nach fundierter wissenschaftlicher Information, begibt sich an den heiligsten Ort aller Bücher - die Universitätsbibliothek. Doch seit einiger Zeit tummeln sich Studierende nicht mehr nur in Bibliotheken, sondern auch immer häufiger im Internet. Sie suchen und finden dort digitale Bücher, sogenannte E-Books. Wie lässt sich der Wandel durch den Einzug des E-Books in das etablierte Forschungssystem beschreiben, welche Konsequenzen lassen sich daraus ablesen und wird schließlich alles digital, sogar die Bibliothek? Diesen Fragen geht ein elfköpfiges Expertenteam aus Deutschland und der Schweiz während der zweitägigen Konferenz auf den Grund. Bei den Weimarer E-DOC-Tagen geht es nun um die Veränderung des institutionellen Gefüges rund um das digitale Buch. Denn traditionell sind Verlage und Bibliotheken wichtige Bestandteile der Wissensversorgung in Studium und Lehre. Doch mit dem Aufkommen des E-Books verlagert sich die Recherche mehr und mehr ins Internet. Die Suchmaschine Google tritt als neuer Konkurrent der klassischen Bibliotheksrecherche auf. Aber auch Verlage müssen verstärkt auf die neuen Herausforderungen eines digitalen Buchmarktes reagieren. In Kooperation mit der Universitätsbibliothek und dem Master-Studiengang Medienmanagement diskutieren Studierende, Wissenschaftler, Bibliothekare und Verleger, wie das E-Book unseren Umgang mit Literatur verändert. Der Tagungsband stellt alle Perspektiven und Ergebnisse zum Nachlesen zusammen. Weimar Verlag der Bauhaus-Universität ca. 110 978-3-86068-454-2 urn:nbn:de:gbv:wim2-20120223-15699 10.25643/bauhaus-universitaet.1569 Professur Medienmanagement OPUS4-3381 Wissenschaftlicher Artikel Zhao, Jun-Hua; Guo, Wanlin; Rabczuk, Timon An analytical molecular mechanics model for the elastic properties of crystalline polyethylene We present an analytical model to relate the elastic properties of crystalline polyethylene based on a molecular mechanics approach. Along the polymer chains direction, the united-atom (UA) CH2-CH2 bond stretching, angle bending potentials are replaced with equivalent Euler-Bernoulli beams. Between any two polymer chains, the explicit formulae are derived for the van der Waals interaction represented by the linear springs of different stiffness. Then, the nine independent elastic constants are evaluated systematically using the formulae. The analytical model is finally validated by present united-atom molecular dynamics (MD) simulations and against available all-atom molecular dynamics results in the literature. The established analytical model provides an efficient route for mechanical characterization of crystalline polymers and related materials. Journal of Applied Physics 10.1063/1.4745035 Institut für Strukturmechanik (ISM) OPUS4-3393 Wissenschaftlicher Artikel Simpson, R.; Bordas, Stéphane Pierre Alain; Trevelyan, J.; Kerfriden, Pierre; Rabczuk, Timon An Isogeometric Boundary Element Method for elastostatic analysis The concept of isogeometric analysis, where functions that are used to describe geometry in CAD software are used to approximate the unknown fields in numerical simulations, has received great attention in recent years. The method has the potential to have profound impact on engineering design, since the task of meshing, which in some cases can add significant overhead, has been circumvented. Much of the research effort has been focused on finite element implementations of the isogeometric concept, but at present, little has been seen on the application to the Boundary Element Method. The current paper proposes an Isogeometric Boundary Element Method (BEM), which we term IGABEM, applied to two-dimensional elastostatic problems using Non-Uniform Rational B-Splines (NURBS). We find it is a natural fit with the isogeometric concept since both the NURBS approximation and BEM deal with quantities entirely on the boundary. The method is verified against analytical solutions where it is seen that superior accuracies are achieved over a conventional quadratic isoparametric BEM implementation. Computer Methods in Applied Mechanics and Engineering 10.1016/j.cma.2011.08.008 Institut für Strukturmechanik (ISM) OPUS4-1799 Dissertation Wendler, André Anachronismen: Historiografie und Kino Die Arbeit »Anachronismen: Historiografie und Kino« geht von einer zunächst einfachen Beobachtung aus: beinahe immer, wenn Historiker_innen sich mit Geschichtsfilmen auseinander setzen, findet sich die lautstark geführte Beschwerde über die zahlreichen und vermeidbaren Anachronismen der Filme, die sie als ernst zu nehmende historiografische Beiträge desavouieren. Von hier ausgehend verfolgt die Arbeit ein dreifaches Projekt: zunächst in einer kritischen Analyse geschichtstheoretischer Texte einige Hinweise für den Status von Anachronismen für die moderne westliche Historiografie zu gewinnen. Zweitens zu untersuchen, welche Rolle Anachronismen für den Geschichtsfilm spielen. Und drittens von dort aus das epistemische Potential anachronistischen Geschichtskinos zu untersuchen. Eine der Hauptthesen, welche den Blick sowohl auf die Filme wie auf die theoretischen Texte leitet, besagt, dass Anachronismen genau jene Punkte sind, an denen die Medien einer jeden Geschichtsschreibung beobachtbar werden. Die Beobachtung und Beschreibung dieser Medien der kinematografischen Geschichtsschreibung unternimmt die Arbeit unter Zuhilfenahme einiger theoretischer Überlegungen der Actor Network Theory (ANT). Die Arbeit ist in vier Kapitel gegliedert, in deren Zentrum jeweils die Diskussion eines ANT-Begriffs sowie die Analyse eines Geschichtsfilmes steht. Zu den untersuchten Filmen gehören Shutter Island (Martin Scorsese, 2010), Chronik der Anna Magdalena Bach (Jean-Marie Straub/Danièle Huillet, 1968), Cleopatra (Joseph L. Mankiewicz, 1963) und Caravaggio (Derek Jarman, 1986). Die Arbeit kommentiert außerdem theoretische Texte zur Historiografie und zu Anachronismen von Walter Benjamin, Leo Bersani, Georges Didi-Huberman, Siegfried Kracauer, Friedrich Meinecke, Friedrich Nietzsche, Jacques Rancière, Leopold Ranke, Paul Ricœur, Georg Simmel, Hayden White u. a. 284+81 urn:nbn:de:gbv:wim2-20121219-17991 10.25643/bauhaus-universitaet.1799 Professur Medienphilosophie OPUS4-1541 Masterarbeit / Diplomarbeit Esser, Julia Analyse von Einflussparametern auf bogenförmige überschnittene Bohrpfahlwände mit mehreren unbewehrten Zwischenpfählen wasserdichte Baugrubenumschließungen tiefer Baugruben mittels bogenförmiger, überschnittener Bohrpfahlwände 2011 urn:nbn:de:gbv:wim2-20120203-15416 10.25643/bauhaus-universitaet.1541 Professur Grundbau OPUS4-2782 Konferenzveröffentlichung Nechytailo, Oleksandr; Horokhov, Yevgen; Kushchenko, Vladimir Gürlebeck, Klaus; Lahmer, Tom; Werner, Frank ANALYSIS OF THE MODE OF DEFORMATION OF THE SUB-PULLEY STRUCTURES ON SHAFT SLOPING HEADGEAR STRUCTURES A numerical analysis of the mode of deformation of the main load-bearing components of a typical frame sloping shaft headgear was performed. The analysis was done by a design model consisting of plane and solid finite elements, which were modeled in the program «LIRA». Due to the numerical results, the regularities of local stress distribution under a guide pulley bearing were revealed and parameters of a plane stress under both emergency and normal working loads were determined. In the numerical simulation, the guidelines to improve the construction of the joints of guide pulleys resting on sub-pulley frame-type structures were established. Overall, the results obtained are the basis for improving the engineering procedures of designing steel structures of shaft sloping headgear. 16 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27826 10.25643/bauhaus-universitaet.2782 Graduiertenkolleg 1462 OPUS4-1589 Dissertation Karaki, Ghada Assessment of coupled models of bridges considering time-dependent vehicular loading Bridge vibration due to traffic loading has been a subject of extensive research in the last decades. The focus of such research has been to develop solution algorithms and investigate responses or behaviors of interest. However, proving the quality and reliability of the model output in structural engineering has become a topic of increasing importance. Therefore, this study is an attempt to extend concepts of uncertainty and sensitivity analyses to assess the dynamic response of a coupled model in bridge engineering considering time-dependent vehicular loading. A setting for the sensitivity analysis is proposed, which enables performing the sensitivity analysis considering random stochastic processes. The classical and proposed sensitivity settings are used to identify the relevant input parameters and models that have the most influence on the variance of the dynamic response. The sensitivity analysis exercises the model itself and extracts results without the need for measurements or reference solutions; however, it does not offer a means of ranking the coupled models studied. Therefore, concepts of total uncertainty are employed to rank the coupled models studied according to their fitness in describing the dynamic problem. The proposed procedures are applied in two examples to assess the output of coupled subsystems and coupled partial models in bridge engineering considering the passage of a heavy vehicle at various speeds. 184 urn:nbn:de:gbv:wim2-20120402-15894 10.25643/bauhaus-universitaet.1589 Graduiertenkolleg 1462 OPUS4-2766 Konferenzveröffentlichung Jung, Bastian; Morgenthal, Guido Gürlebeck, Klaus; Lahmer, Tom; Werner, Frank ASSESSMENT OF INTEGRAL BRIDGES USING QUANTITATIVE MODEL EVALUATION Numerical simulations in the general field of civil engineering are common for the design process of structures and/or the assessment of existing buildings. The behaviour of these structures is analytically unknown and is approximated with numerical simulation methods like the Finite Element Method (FEM). Therefore the real structure is transferred into a global model (GM, e.g. concrete bridge) with a wide range of sub models (partial models PM, e.g. material modelling, creep). These partial models are coupled together to predict the behaviour of the observed structure (GM) under different conditions. The engineer needs to decide which models are suitable for computing realistically and efficiently the physical processes determining the structural behaviour. Theoretical knowledge along with the experience from prior design processes will influence this model selection decision. It is thus often a qualitative selection of different models. The goal of this paper is to present a quantitative evaluation of the global model quality according to the simulation of a bridge subject to direct loading (dead load, traffic) and indirect loading (temperature), which induce restraint effects. The model quality can be separately investigated for each partial model and also for the coupled partial models in a global structural model. Probabilistic simulations are necessary for the evaluation of these model qualities by using Uncertainty and Sensitivity Analysis. The method is applied to the simulation of a semi-integral concrete bridge with a monolithic connection between the superstructure and the piers, and elastomeric bearings at the abutments. The results show that the evaluation of global model quality is strongly dependent on the sensitivity of the considered partial models and their related quantitative prediction quality. This method is not only a relative comparison between different models, but also a quantitative representation of model quality using probabilistic simulation methods, which can support the process of model selection for numerical simulations in research and practice. 10 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27662 10.25643/bauhaus-universitaet.2766 Graduiertenkolleg 1462 OPUS4-2673 Wissenschaftlicher Artikel Knecht, Katja; König, Reinhard Automatische Grundstücksumlegung mithilfe von Unterteilungsalgorithmen und typenbasierte Generierung von Stadtstrukturen Dieses Arbeitspapier beschreibt, wie ausgehend von einem vorhandenen Straßennetzwerk Bebauungsareale mithilfe von Unterteilungsalgorithmen automatisch umgelegt, d.h. in Grundstücke unterteilt, und anschließend auf Basis verschiedener städtebaulicher Typen bebaut werden können. Die Unterteilung von Bebauungsarealen und die Generierung von Bebauungsstrukturen unterliegen dabei bestimmten stadtplanerischen Einschränkungen, Vorgaben und Parametern. Ziel ist es aus den dargestellten Untersuchungen heraus ein Vorschlagssystem für stadtplanerische Entwürfe zu entwickeln, das anhand der Umsetzung eines ersten Softwareprototyps zur Generierung von Stadtstrukturen weiter diskutiert wird. urn:nbn:de:gbv:wim2-20160822-26730 10.25643/bauhaus-universitaet.2673 Junior-Professur Computational Architecture OPUS4-1673 Bachelorarbeit Schürenberg, Philipp Automatisierte fachliche Qualitätssicherung in einem Crowdsourcing-basierten bauphysikalischen Lernspiel In crowdsourcingbasierten Systemen kommt der Qualitätssicherung des durch Benutzer generierten Inhaltes große Bedeutung für die Erhaltung der Benutzbarkeit zu. Das bauphysikalische Lehrspiel "BuildVille" benutzt für die Quiz-Anwendung einen Crowdsourcing-Ansatz: Die Quiz-Fragen werden von den Benutzern selbst generiert. Mit Hilfe dieser Arbeit soll sichergestellt werden, dass fehlerhafte, irrtümlicherweise oder zum Spaß eingegebene Fragen möglichst früh erkannt, korrigiert oder von der weiteren Verbreitung ausgeschlossen werden. Dazu soll mit Hilfe einer Analyse bestehender crowdsourcingbasierter Systeme bezüglich umgesetzter Qualitätssicherungsmaßnahmen ein Konzept für die QS-Maßnahmen in BuildVille entwickelt werden. 53 urn:nbn:de:gbv:wim2-20120704-16734 10.25643/bauhaus-universitaet.1673 Professur Bauphysik OPUS4-2785 Konferenzveröffentlichung Schmeikal, Bernd Anton Gürlebeck, Klaus; Lahmer, Tom; Werner, Frank BAUHAUS ISOMETRY AND FIELDS While integration increases by networking, segregation strides ahead too. Most of us fixate our mind on special topics. Yet we are relying on our intuition too. We are sometimes waiting for the inflow of new ideas or valuable information that we hold in high esteem, although we are not entirely conscious of its origin. We may even say the most precious intuitions are rooting in deep subconscious, collective layers of the mind. Take as a simple example the emergence of orientation in paleolithic events and its relation to the dihedral symmetry of the compass. Consider also the extension of this algebraic matter into the operational structures of the mind on the one hand and into the algebra of geometry, Clifford algebra as we use to call it today, on the other. Culture and mind, and even the individual act of creation may be connected with transient events that are subconscious and inaccessible to cognition in principle. Other events causative for our work may be merely invisible too us, though in principle they should turn out attainable. In this case we are just ignorant of the whole creative process. Sometimes we begin to use unusual tools or turn into handicraft enthusiasts. Then our small institutes turn into workshops and factories. All this is indeed joining with the Bauhaus and its spirit. We shall go together into this, and we shall present a record of this session. 9 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27859 10.25643/bauhaus-universitaet.2785 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-1772 Bachelorarbeit Franke, Carolin Bauphysikalisches Quartett Quartett ist ein ebenso altes, wie auch beliebtes Kartenspiel. Vor allem bei Kindern erfreut es sich großer Beliebtheit, während in den älteren Generationen kaum jemand mit Quartettkarten spielt. Quartettspiele speziell für Kleinkinder sind zum Großteil mit Inhalten versehen, die Wissen auf spielerische Art und Weise vermitteln. Dabei werden gute Lernerfolge in dieser Zielgruppe verzeichnet. Wie lassen sich also diese Lernerfolge durch das Spielen mit Quartettkarten erzielen? Und wie kann dieser Effekt auch auf Studenten übertragen werden? Ziel dieser Arbeit ist es, das Konzept des Quartettkartenspiels auf bauphysikalische Inhalte anzuwenden und gegebenenfalls die Spielprinzipien zu erweitern oder zu verändern. Dabei sind die Studenten der Fakultät Bauingenieurswesen die Zielgruppe, an die sich das Spiel richten soll. Besondere Herausforderung ist es, unterschiedliche Objekteklassen von bauphysikalischer Relevanz in einem Spiel zusammenzubringen und vergleichbar zu machen. Das sich ergebende Quartettkartenspiel sollte nicht nur eine Objektklasse, sondern mehrere Objektklassen zum Inhalt haben. Dabei sollen die Objektklassen so gewählt werden, dass sich Kategorien mit bauphysikalischem Inhalt finden lassen. Augenmerk sollte auch auf die Strukturierung der Lerninhalte gelegt werden, um eine leichte Übertragung des Spielkonzepts auf andere Fachdomänen zu ermöglichen. Das Ergebnis der Arbeit sind zwei fertige und spielbare Quartette. 74 urn:nbn:de:gbv:wim2-20121130-17723 10.25643/bauhaus-universitaet.1772 Professur Bauphysik OPUS4-1556 Dissertation Keitel, Holger Bewertungsmethoden für die Prognosequalität von Kriechmodellen des Betons Ziel dieser Arbeit ist die Entwicklung von Methoden, mit denen die Prognosequalität von Kriechmodellen des Betons bestimmt werden kann. Die Methoden werden in zwei Ausgangsszenarien unterschieden: die Bewertung ohne und die Bewertung mit Verwendung von spezifischen Versuchsdaten zum Kriechverhalten des Betons. Die Modellqualität wird anhand der Gesamtunsicherheit der prognostizierten Kriechnachgiebigkeit quantifiziert. Die Unsicherheit wird für die Kriechprognose ohne Versuchsdaten über eine Unsicherheitsanalyse unter Berücksichtigung korrelierter Eingangsparameter ermittelt. Bei der Verwendung experimenteller Daten werden die stochastischen Eigenschaften der Modellparameter mittels Bayesian Updating bestimmt. Die Bewertung erfolgt erneut basierend auf einer Unsicherheitsanalyse sowie alternativ mittels Modellselektion nach Bayes. Weiterhin wird eine auf Graphentheorie und Sensitivitätsanalysen basierende Methode zur Bewertung von gekoppelten Partialmodellen entwickelt. Damit wird der Einfluss eines Partialmodells auf das Verhalten einer globalen Tragstruktur quantifiziert, Interaktionen von Partialmodellen festgestellt und ein Maß für die Qualität eines Gesamtmodells ermittelt. Weimar Verlag der Bauhaus-Universität Weimar 390 978-3-86068-466-5 urn:nbn:de:gbv:wim2-20120207-15569 10.25643/bauhaus-universitaet.1556 Graduiertenkolleg 1462 OPUS4-2788 Konferenzveröffentlichung Suzuki, Osamu; Lawrynowicz, Julian; Nouno, Kiyoharu; Nagayama, Daiki Gürlebeck, Klaus; Lahmer, Tom; Werner, Frank BINARY AND TERNARY CLIFFORD ANALYSIS ON NONION ALGEBRA AND SU(3) A concept of non-commutative Galois extension is introduced and binary and ternary extensions are chosen. Non-commutative Galois extensions of Nonion algebra and su(3) are constructed. Then ternary and binary Clifford analysis are introduced for non-commutative Galois extensions and the corresponding Dirac operators are associated. 12 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27880 10.25643/bauhaus-universitaet.2788 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-1753 Studienarbeit Großmann, Felix Capturing Sheep With Minecraft Capturing Sheep With Minecraft befasst sich mit ausgewählten Problemen der Bauphysik und deren Umsetzung mithilfe des Computerspiels Minecraft. Es werden ausgewählte Probleme der Bauphysik in Minecraft abgebildet um diese Schülern und Studenten näher zu bringen. Es wurde ein Szenario in Minecraft entworfen welches durch entgegenwirken der abgebildeten Probleme, durch den Spieler gelöst werden soll. 24 urn:nbn:de:gbv:wim2-20121107-17530 10.25643/bauhaus-universitaet.1753 Professur Bauphysik OPUS4-2778 Konferenzveröffentlichung Morais, Joao; Georgiev, Svetlin Gürlebeck, Klaus; Lahmer, Tom; Werner, Frank COMPLETE ORTHOGONAL SYSTEMS OF 3D SPHEROIDAL MONOGENICS In this paper we review two distint complete orthogonal systems of monogenic polynomials over 3D prolate spheroids. The underlying functions take on either values in the reduced and full quaternions (identified, respectively, with R3 and R4), and are generally assumed to be nullsolutions of the well known Riesz and Moisil Théodoresco systems in R3. This will be done in the spaces of square integrable functions over R and H. The representations of these polynomials are explicitly given. Additionally, we show that these polynomial functions play an important role in defining the Szegö kernel function over the surface of 3D spheroids. As a concrete application, we prove the explicit expression of the monogenic Szegö kernel function over 3D prolate spheroids. 14 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27785 10.25643/bauhaus-universitaet.2778 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-3389 Wissenschaftlicher Artikel Nguyen-Xuan, Hung; Rabczuk, Timon; Nguyen-Thoi, T.; Tran, T.; Nguyen-Thanh, Nhon Computation of limit and shakedown loads using a node-based smoothed finite element method This paper presents a novel numerical procedure for computing limit and shakedown loads of structures using a node-based smoothed FEM in combination with a primal-dual algorithm. An associated primal-dual form based on the von Mises yield criterion is adopted. The primal-dual algorithm together with a Newton-like iteration are then used to solve this associated primal-dual form to determine simultaneously both approximate upper and quasi-lower bounds of the plastic collapse limit and the shakedown limit. The present formulation uses only linear approximations and its implementation into finite element programs is quite simple. Several numerical examples are given to show the reliability, accuracy, and generality of the present formulation compared with other available methods. 23 International Journal for Numerical Methods in Engineering 287 310 10.1002/nme.3317 Institut für Strukturmechanik (ISM) OPUS4-2759 Konferenzveröffentlichung Castillo-Pérez, Raúl; Cedillo - Díaz, A. del C.; Kravchenko, Vladislav; Oviedo - Galdeano, H. Gürlebeck, Klaus; Lahmer, Tom; Werner, Frank COMPUTATION OF THE REFLECTANCE AND TRANSMITTANCE FOR AN INHOMOGENEOUS LAYERED MEDIUM WITH TURNING POINT S USING THE WKB AND SPPS METHODS Electromagnetic wave propagation is currently present in the vast majority of situations which occur in veryday life, whether in mobile communications, DTV, satellite tracking, broadcasting, etc. Because of this the study of increasingly complex means of propagation of lectromagnetic waves has become necessary in order to optimize resources and increase the capabilities of the devices as required by the growing demand for such services. Within the electromagnetic wave propagation different parameters are considered that characterize it under various circumstances and of particular importance are the reflectance and transmittance. There are several methods or the analysis of the reflectance and transmittance such as the method of approximation by boundary condition, the plane wave expansion method (PWE), etc., but this work focuses on the WKB and SPPS methods. The implementation of the WKB method is relatively simple but is found to be relatively efficient only when working at high frequencies. The SPPS method (Spectral Parameter Powers Series) based on the theory of pseudoanalytic functions, is used to solve this problem through a new representation for solutions of Sturm Liouville equations and has recently proven to be a powerful tool to solve different boundary value and eigenvalue problems. Moreover, it has a very suitable structure for numerical implementation, which in this case took place in the Matlab software for the valuation of both conventional and turning points profiles. The comparison between the two methods allows us to obtain valuable information about their perfor mance which is useful for determining the validity and propriety of their application for solving problems where these parameters are calculated in real life applications. 16 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170306-27598 10.25643/bauhaus-universitaet.2759 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2791 Konferenzveröffentlichung Wudtke, Idna Gürlebeck, Klaus; Lahmer, Tom; Werner, Frank CONSTITUTIVE MODELING OF CRYSTALLINE MATERIALS WITH TEXTURE CHARACTERISTICS The analysis of the response of complex structural systems requires the description of the material constitutive relations by means of an appropriate material model. The level of abstraction of such model may strongly affect the quality of the prognosis of the whole structure. In context to this fact, it is necessary to describe the material in a convenient sense as exact but as simple as possible. All material phenomena of crystalline materials e.g. steel, affecting the behavior of the structure, rely on physical effects which are interacting over spatial scales from subatomic to macroscopic range. Nevertheless, if the material is microscopically heterogenic, it might be appropriate to use phenomenological models for the purpose of civil engineering. Although constantly applied, these models are insufficient for steel materials with microscopic characteristics such as texture, typically occurring in hot rolled steel members or heat affected zones of welded joints. Hence, texture is manifested in crystalline materials as a regular crystallographic structure and crystallite orientation, influencing macroscopic material properties. The analysis of structural response of material with texture (e.g. rolled steel or heat affected zone of a welded joint) obliges the extension of the phenomenological material description of macroscopic scale by means of microscopic information. This paper introduces an enrichment approach for material models based on a hierarchical multiscale methodology. This has been done by describing the grain texture on a mesoscopic scale and coupling it with macroscopic constitutive relations by means of homogenization. Due to a variety of available homogenization methods, the question of an assessment of coupling quality arises. The applicability of the method and the effect of the coupling method on the reliability of the response are presented on an example. 9 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27910 10.25643/bauhaus-universitaet.2791 Graduiertenkolleg 1462 OPUS4-1775 misc Simon-Ritz, Frank; Liehr, Harald S. Das Urheberrecht - ein Pulverfass für Lehre und Forschung Radiodiskussion bei bauhaus.fm am 5. November 2012. Harald S. Liehr ist Lektor und Leiter der Niederlassung Weimar des Böhlau-Verlags (Wien / Köln / Weimar), Dr. Frank Simon-Ritz ist Direktor der Universitätsbibliothek der Bauhaus-Universität Weimar. Die Fragen stellten René Tauschke und Jean-Marie Schaldach. urn:nbn:de:gbv:wim2-20121130-17753 10.25643/bauhaus-universitaet.1775 Universitätsbibliothek OPUS4-2767 Konferenzveröffentlichung Karaki, Ghada Gürlebeck, Klaus; Lahmer, Tom; Werner, Frank DEPENDENCY OF THE INFLUENCE OF INPUT PARAMETERS OF BVI MODELS ON THE INITIAL EXCITATIONS AND SPEED RANGES Bridge vibration due to traffic loading has been subject of extensive research in the last decades. Such studies are concerned with deriving solutions for the bridge-vehicle interaction (BVI) and analyzing the dynamic responses considering randomness of the coupled model's (BVI) input parameters and randomness of road unevenness. This study goes further to examine the effects of such randomness of input parameters and processes on the variance of dynamic responses in quantitative measures. The input parameters examined in the sensitivity analysis are, stiffness and damping of vehicle's suspension system, axle spacing, and stiffness and damping of bridge. This study also examines the effects of the initial excitation of a vehicle on the influences of the considered input parameters. Variance based sensitivity analysis is often applied to deterministic models. However, the models for the dynamic problem is a stochastic one due to the simulations of the random processes. Thus, a setting using a joint meta-model; one for the mean response and other for the dispersion of the response is developed. The joint model is developed within the framework of Generalized Linear Models (GLM). An enhancement of the GLM procedure is suggested and tested; this enhancement incorporates Moving Least Squares (MLS) approximation algorithms in the fitting of the mean component of the joint model. The sensitivity analysis is then performed on the joint-model developed for the dynamic responses caused by BVI. 13 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27675 10.25643/bauhaus-universitaet.2767 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-1598 Teil eines Buches Trommershausen, Anke Die schwerelose Ökonomie auf der Suche nach ihrem Gewicht : wissenschaftliche E-Books in den USA Beitrag während der Weimarer EDOC-Tage 2011 Weimar Verlag der Bauhaus-Universität 12 Alles digital? : E-Books in Studium und Lehre 80 92 urn:nbn:de:gbv:wim2-20120404-15987 10.25643/bauhaus-universitaet.1598 Universitätsbibliothek OPUS4-2790 Konferenzveröffentlichung Musial, Michal; Kamiński, Mieczysław; Ubysz, Andrzej Gürlebeck, Klaus; Lahmer, Tom; Werner, Frank DISCRETE CRACK MODEL OF BORCZ FOR CALCULATING THE DEFLECTIONS OF BENDING REINFORCED CONCRETE BEAM In the design of the reinforced concrete beams loaded by the bending moment, it is assumed that the structure can be used at a level of load, that there are local discontinuities - cracks. Designing the element demands checking two limit states of construction, load capacity and usability. Limit states usability include also the deflection of the element. Deflections in the reinforced concrete beams with cracks are based on actual rigidity of the element. After cracking there is a local change in rigidity of the beam. The rigidity is variable in the element's length and due to the heterogeneous structure of concrete, it is not possible to clearly describe those changes. Most standards of testing methods tend to simplify the calculations and take the average value of the beam's rigidity on its entire length. The rigidity depends on the level of the maximal load of the beam. Experimental researches verify the value by inserting the coefficients into the formulas used in the theory of elasticity. The researches describe the changes in rigidity in the beam's length more precisely. The authors take into consideration the change of rigidity, depending on the level of maximum load (continuum models), or localize the changes in rigidity in the area of the cracks (discrete models). This paper presents one of the discrete models. It is distinguished by the fact that the left side of the differential equation, that depends on the rigidity, is constant, and all effects associated with the scratches are taken as the external load and placed on the right side of the equation. This allows to generalize the description. The paper presents a particular integral of the differential equation, which allow analyzing the displacement and vibration for different rigidity of the silo's walls, the flow rate and type of the flowing material. 11 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27907 10.25643/bauhaus-universitaet.2790 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-1595 Teil eines Buches Upmeier, Arne E-Books : Die Frustrationen des Urheberrechts Beitrag während der Weimarer EDOC-Tage 2011 Weimar Verlag der Bauhaus-Universität 5 Alles digital? : E-Books in Studium und Lehre 66 71 urn:nbn:de:gbv:wim2-20120404-15954 10.25643/bauhaus-universitaet.1595 Universitätsbibliothek OPUS4-1594 Teil eines Buches Mirallas Hernandez, Catherine E-Books : Interessenkonflikte zwischen Bibliotheken, Nutzern und Verlagen Beitrag während der Weimarer EDOC-Tage 2011 Weimar Verlag der Bauhaus-Universität 9 Alles digital? : E-Books in Studium und Lehre 54 63 urn:nbn:de:gbv:wim2-20120404-15941 10.25643/bauhaus-universitaet.1594 Universitätsbibliothek OPUS4-1597 Teil eines Buches Simon-Ritz, Frank E-Books an einer kleinen Universitätsbibliothek : Probleme und Perspektiven Beitrag während der Weimarer EDOC-Tage 2011 Weimar Verlag der Bauhaus-Universität 3 Alles digital? : E-Books in Studium und Lehre 74 77 urn:nbn:de:gbv:wim2-20120404-15977 10.25643/bauhaus-universitaet.1597 Universitätsbibliothek OPUS4-1591 Teil eines Buches Mumenthaler, Rudolf E-Books und E-Reader als Herausforderung für Bibliotheken Beitrag während der Weimarer EDOC-Tage 2011 Weimar Verlag der Bauhaus-Universität 7 Alles digital? : E-Books in Studium und Lehre 44 51 urn:nbn:de:gbv:wim2-20120403-15913 10.25643/bauhaus-universitaet.1591 Universitätsbibliothek OPUS4-1599 Teil eines Buches Wasserek, Moritz Enhanced E-Books : Veränderungen und Chancen für Akteure der Buchbranche durch die Einführung elektronischer Lesegeräte Beitrag während der Weimarer EDOC-Tage 2011 Weimar Verlag der Bauhaus-Universität 14 Alles digital? : E-Books in Studium und Lehre 96 110 urn:nbn:de:gbv:wim2-20120404-15996 10.25643/bauhaus-universitaet.1599 Universitätsbibliothek OPUS4-3379 Wissenschaftlicher Artikel Jiang, Jin-Wu; Park, Harold S.; Rabczuk, Timon Enhancing the mass sensitivity of graphene nanoresonators via nonlinear oscillations: The effective strain mechanism Enhancing the mass sensitivity of graphene nanoresonators via nonlinear oscillations: The effective strain mechanism Nanotechnology Institut für Strukturmechanik (ISM) OPUS4-1644 Bachelorarbeit Böwe, Annelie Entscheidungsfindung im Herstellungsprozess von Brückenkappen Im Rahmen dieser Arbeit wurde die Entscheidungsfindung im Herstellungsprozess von Brückenkappen untersucht. Es stellte sich heraus, dass die Fuzzy-Methode ein geeignetes Werkzeug sein könnte, die Teilprozesse auf die Möglichkeit ihrer Parallelisierung hin zu untersuchen. Um diese Theorie zu testen, wurde auf den Grundlagen von Arbeiten der Professur Baubetrieb und Bauverfahren der Prozess näher analysiert und unterstützend durch eigene Recherchen ein UML-Diagramm erstellt, welches als Aktivitätsdiagramm ausgebildet wurde. Aufbauend auf diesem Ablauf und den gewonnenen Kenntnissen zur Herstellung einer Brückenkappe, konnten die einzelnen Prozesse zu Teilprozessen, sogenannten Bausteinen, zusammengefasst werden. Diese Bausteine sind entstanden, um die Simulation möglich zu machen, indem der Ablauf weniger komplex wird und nur die Prozesse zu beurteilen sind, die beeinflusst bzw. in ihrer Reihenfolge bis zu einem gewissen Grad variabel sind. Eine erleichterte Interaktion mit den Bausteinen und deren Überführung in ein Simulationsprogramm wurde über Templates realisiert. So besitzt jeder Baustein eine einheitliche Struktur. Unter anderem beinhalten die Bausteine die jeweiligen Ressourcen und Parameter, sowie die Abhängigkeiten der Prozesse untereinander und die zugehörige Priorität. Zur Entscheidungsfindung wurde die Fuzzylogik herangezogen und die Problemstellung der Parallelisierung zum Ziel gesetzt. Die Realisierung wurde über einen Entscheidungsbaum und das daraus resultierende Regelwerk erreicht. Somit ließen sich, ausgehend von einem festgelegten Prozess und durch die Fuzzifizierung der Eingangsparameter Priorität, Prozessdauer und Verfügbarkeit der Ressourcen und Arbeitskräfte, verschiedene Pfade identifizieren, allerdings nur in Verbindung mit den vorher analysierten Abhängigkeiten. Für jeden der Eingangsparameter wurden so Fuzzy-Sets erstellt. Über den Entscheidungsbaum, welcher mit den linguistischen Variablen versehen wurde, konnte über sogenannte "und" - Verknüpfungen das Regelwerk aufgestellt werden. Das gekürzte Regelwerk in dieser Arbeit beinhaltet grundsätzlich nur die Regeln, die auch zu einer wirklichen Entscheidung führen. Daraus folgt, dass es möglich ist mittels der Fuzzy-Methode eine Entscheidung darüber zu fällen, ob zwei Prozesse zu parallelisieren sind oder nicht und aufgetretene Verzögerungen wieder eingeholt werden können. urn:nbn:de:gbv:wim2-20120425-16447 10.25643/bauhaus-universitaet.1644 Professur Baubetrieb und Bauverfahren OPUS4-1522 Bachelorarbeit Kühnert, Christin Entwicklung von Spielmechaniken für ein bauphysikalisches Social Game Eine der jüngsten Entwicklungen in der Games Branche sind sogenannte Social Games. Hierbei handelt es sich um digitale Spiele, die innerhalb von sozialen Netzwerken, wie z.B. Facebook und Myspace, gespielt werden. Studien zeigen, dass kommerzielle digitale Spiele mehr als nur ein Zeitvertreib sind. Sie fördern sowohl kognitive, als auch affektive und psychomotorische Kompetenzen. Aus diesem Grund werden seit Jahrzehnten digitale Spiele in der Pädagogik eingesetzt, um ihre Motivationskraft zu nutzen, um Lerneffekte zu erzielen. Ziel dieser Arbeit ist es Spielmechaniken für ein bauphysikalisches Social Game zu entwickeln. Ausgehend von der Identifikation von Spielmechaniken, basierend auf einer Analyse der Funktionsweisen existierender populärer Social Games, und einem grundlegenden pädagogischen Verständnis bezüglich Digital Game Based Learning (DGBL), werden Spielmechaniken entwickelt, mit deren Hilfe bauphysikalische Fachkompetenzen vermittelt werden können. 2011 urn:nbn:de:gbv:wim2-20120117-15227 10.25643/bauhaus-universitaet.1522 Professur Bauphysik OPUS4-1524 Bachelorarbeit Held, Janina Entwurf eines Spieler-Modells für eine erweiterbare Spielplattform zur Ausbildung in der Bauphysik Im Projekt Intelligentes Lernen beschäftigen sich die Professuren Content Management und Web-Technologien, Systeme der Virtuellen Realität und Bauphysik der Bauhaus- Universität Weimar mit der Entwicklung innovativer Informationstechnologien für eLearning- Umgebungen. In den Teilbereichen Retrieval, Extraktion und Visualisierung großer Dokumentkollektionen, sowie simulations- und planbasierter Wissensvermittlung werden Algorithmen und Werkzeuge erforscht, um eLearning-Systeme leistungsfähiger zu machen und um somit den Lernerfolg zu optimieren. Ziel des Projekts, auf dem Gebiet des simulationsbasierten Wissenstransfers, ist die Entwicklung eines Multiplayer Online Games (MOG) zur Ausbildungsunterstützung in der Bauphysik. Im Rahmen der vorliegenden Bachelorarbeit wird für diese digitale Lernsoftware ein Spieler- Modell zur Verwaltung der spielerspezifischen Daten entworfen und in das bestehende Framework integriert. Der Schwerpunkt der Arbeit liegt in der Organisation der erlernten Fähigkeiten des Spielers und in der an den Wissensstand angepassten Auswahl geeigneter Spielaufgaben. Für die Anwendung im eLearning-Bereich ist die Erweiterbarkeit des Modells um neue Lernkomplexe eine wesentliche Anforderung. 2011 65 urn:nbn:de:gbv:wim2-20120117-15249 10.25643/bauhaus-universitaet.1524 Professur Bauphysik OPUS4-2670 Wissenschaftlicher Artikel Köhler, Hermann Ergebnisse der Befragung zu Wohnstandortpräferenzen von Lebensweltsegmenten in Dresden In vorliegender Studie werden die Wohnstandortpräferenzen der Sinus-Milieugruppen in Dresden über eine standardisierte Befragung (n=318) untersucht. Es wird unterschieden zwischen handlungsleitenden Wohnstandortpräferenzen, die durch Anhaltspunkte auf der Handlungsebene stärker in Betracht gezogen werden sollten, und Wohnstandortpräferenzen, welche eher orientierenden Charakter haben. Die Wohnstandortpräferenzen werden untersucht anhand der Kategorien Ausstattung/Zustand der Wohnung/des näheren Wohnumfeldes, Versorgungsstruktur, soziales Umfeld, Baustrukturtyp, Ortsgebundenheit sowie des Aspektes des Images eines Stadtviertels. Um die Befragten den Sinus-Milieugruppen zuordnen zu können, wird ein Lebensweltsegment-Modell entwickelt, welches den Anspruch hat, die Sinus-Milieugruppen in der Tendenz abzubilden. Die Studie kommt zu dem Ergebnis, dass die Angehörigen der verschiedenen Lebensweltsegmente in jeder Kategorie - wenn auch z.T. auf geringerem Niveau - signifikante Unterschiede in der Bewertung einzelner Wohnstandortpräferenzen aufweisen. urn:nbn:de:gbv:wim2-20160822-26704 10.25643/bauhaus-universitaet.2670 Professur Informatik in der Architektur OPUS4-3117 Wissenschaftlicher Artikel Aguinaga, José Guillermo De Error in prediction due to data type availability in a coupled hydro-mechanical model Different types of data provide different type of information. The present research analyzes the error on prediction obtained under different data type availability for calibration. The contribution of different measurement types to model calibration and prognosis are evaluated. A coupled 2D hydro-mechanical model of a water retaining dam is taken as an example. Here, the mean effective stress in the porous skeleton is reduced due to an increase in pore water pressure under drawdown conditions. Relevant model parameters are identified by scaled sensitivities. Then, Particle Swarm Optimization is applied to determine the optimal parameter values and finally, the error in prognosis is determined. We compare the predictions of the optimized models with results from a forward run of the reference model to obtain the actual prediction errors. The analyses presented here were performed calibrating the hydro-mechanical model to 31 data sets of 100 observations of varying data types. The prognosis results improve when using diversified information for calibration. However, when using several types of information, the number of observations has to be increased to be able to cover a representative part of the model domain. For an analysis with constant number of observations, a compromise between data type availability and domain coverage proves to be the best solution. Which type of calibration information contributes to the best prognoses could not be determined in advance. The error in model prognosis does not depend on the error in calibration, but on the parameter error, which unfortunately cannot be determined in inverse problems since we do not know its real value. The best prognoses were obtained independent of calibration fit. However, excellent calibration fits led to an increase in prognosis error variation. In the case of excellent fits; parameters' values came near the limits of reasonable physical values more often. To improve the prognoses reliability, the expected value of the parameters should be considered as prior information on the optimization algorithm. 12 Electronic Journal of Geotechnical Engineering 2459 2471 urn:nbn:de:gbv:wim2-20170413-31170 10.25643/bauhaus-universitaet.3117 Graduiertenkolleg 1462 OPUS4-1676 Bachelorarbeit Müller, Naira Erweiterung von Fliplife mit bauphysikalischen Inhalten In dieser Arbeit wurde ein Konzept erstellt, das Fliplife um einen bauphysikalischen Karriereweg erweitert. In das Spiel wurden beispielhaft bauphysikalische Inhalte sowie spielkonzept-kompatible und wissensvermittelnde Spielmechaniken implementiert. 105 urn:nbn:de:gbv:wim2-20120704-16763 10.25643/bauhaus-universitaet.1676 Professur Bauphysik OPUS4-2787 Konferenzveröffentlichung Stutz, Henning; Wuttke, Frank Gürlebeck, Klaus; Lahmer, Tom; Werner, Frank EVALUATION OF SOIL-STRUCTURE INTERACTION MODELS USING DIFFERENT MODEL-ROBUSTNESS APPROACHES The aim of this study is to show an application of model robustness measures for soilstructure interaction (henceforth written as SSI) models. Model robustness defines a measure for the ability of a model to provide useful model answers for input parameters which typically have a wide range in geotechnical engineering. The calculation of SSI is a major problem in geotechnical engineering. Several different models exist for the estimation of SSI. These can be separated into analytical, semi-analytical and numerical methods. This paper focuses on the numerical models of SSI specific macro-element type models and more advanced finite element method models using contact description as continuum or interface elements. A brief description of the models used is given in the paper. Following this description, the applied SSI problem is introduced. The observed event is a static loaded shallow foundation with an inclined load. The different partial models to consider the SSI effects are assessed using different robustness measures during numerical application. The paper shows the investigation of the capability to use these measures for the assessment of the model quality of SSI partial models. A variance based robustness and a mathematical robustness approaches are applied. These different robustness measures are used in a framework which allows also the investigation of computational time consuming models. Finally the result shows that the concept of using robustness approaches combined with other model-quality indicators (e.g. model sensitivity or model reliability) can lead to unique model-quality assessment for SSI models. 15 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27878 10.25643/bauhaus-universitaet.2787 Graduiertenkolleg 1462 OPUS4-3384 Wissenschaftlicher Artikel Nguyen-Vinh, H.; Bakar, I.; Msekh, Mohammed Abdulrazzak; Song, Jeong-Hoon; Muthu, Jacob; Zi, Goangseup; Le, P.; Bordas, Stéphane Pierre Alain; Simpson, R.; Natarajan, S.; Lahmer, Tom; Rabczuk, Timon Extended Finite Element Method for Dynamic Fracture of Piezo-Electric Materials We present an extended finite element formulation for dynamic fracture of piezo-electric materials. The method is developed in the context of linear elastic fracture mechanics. It is applied to mode I and mixed mode-fracture for quasi-steady cracks. An implicit time integration scheme is exploited. The results are compared to results obtained with the boundary element method and show excellent agreement. 12 Engineering Fracture Mechanics 19 31 10.1016/j.engfracmech.2012.04.025 Institut für Strukturmechanik (ISM) OPUS4-3390 Wissenschaftlicher Artikel Chen, Lei; Rabczuk, Timon; Liu, G.R.; Zeng, K.Y.; Kerfriden, Pierre; Bordas, Stéphane Pierre Alain Extended finite element method with edge-based strain smoothing (ESm-XFEM) for linear elastic crack growth This paper presents a strain smoothing procedure for the extended finite element method (XFEM). The resulting "edge-based" smoothed extended finite element method (ESm-XFEM) is tailored to linear elastic fracture mechanics and, in this context, to outperform the standard XFEM. In the XFEM, the displacement-based approximation is enriched by the Heaviside and asymptotic crack tip functions using the framework of partition of unity. This eliminates the need for the mesh alignment with the crack and re-meshing, as the crack evolves. Edge-based smoothing (ES) relies on a generalized smoothing operation over smoothing domains associated with edges of simplex meshes, and produces a softening effect leading to a close-to-exact stiffness, "super-convergence" and "ultra-accurate" solutions. The present method takes advantage of both the ES-FEM and the XFEM. Thanks to the use of strain smoothing, the subdivision of elements intersected by discontinuities and of integrating the (singular) derivatives of the approximation functions is suppressed via transforming interior integration into boundary integration. Numerical examples show that the proposed method improves significantly the accuracy of stress intensity factors and achieves a near optimal convergence rate in the energy norm even without geometrical enrichment or blending correction. Computer Methods in Applied Mechanics and Engineering 10.1016/j.cma.2011.08.013 Institut für Strukturmechanik (ISM) OPUS4-1572 Studienarbeit Müller, Naira; Hennig, Christoph; Aubel, Mario; Hesse, Tobias; Schneider, Sascha FlipLife als Mitarbeiterrekrutierungsquelle Ausgehend von der Aufgabenstellung umreißt diese Arbeit die Besonderheiten der Mitarbeiterrekrutierung und deren Anwendung im Internet, im speziellen bei Social-Games, gemessen an dem Spiel FlipLife. 101 urn:nbn:de:gbv:wim2-20120229-15727 10.25643/bauhaus-universitaet.1572 Professur Bauphysik OPUS4-1749 Dissertation Urbina Cazenave, Mario Humberto Gaze Controlled Applications and Optical-See-Through Displays - General Conditions for Gaze Driven Companion Technologies Gaze based human-computer-interaction has been a research topic for over a quarter century. Since then, the main scenario for gaze interaction has been helping handicapped people to communicate an interact with their environment. With the rapid development of mobile and wearable display technologies, a new application field for gaze interaction has appeared, opening new research questions. This thesis investigates the feasibility of mobile gaze based interaction, studying deeply the use of pie menus as a generic and robust widget for gaze interaction as well as visual and perceptual issues on head mounted (wearable) optical see-through displays. It reviews conventional gaze-based selection methods and investigates in detail the use of pie menus for gaze control. It studies and discusses layout issues, selection methods and applications. Results show that pie menus can allocate up to six items in width and multiple depth layers, allowing a fast and accurate navigation through hierarchical levels by using or combining multiple selection methods. Based on these results, several text entry methods based on pie menus are proposed. Character-by-character text entry, text entry with bigrams and with text entry with bigrams derived by word prediction, as well as possible selection methods, are examined in a longitudinal study. Data showed large advantages of the bigram entry methods over single character text entry in speed and accuracy. Participants preferred the novel selection method based on saccades (selecting by borders) over the conventional and well established dwell time method. On the one hand, pie menus showed to be a feasible and robust widget, which may enable the efficient use of mobile eye tracking systems that may not be accurate enough for controlling elements on conventional interface. On the other hand, visual perception on mobile displays technologies need to be examined in order to deduce if the mentioned results can be transported to mobile devices. Optical see-through devices enable observers to see additional information embedded in real environments. There is already some evidence of increasing visual load on the respective systems. We investigated visual performance on participants with a visual search tasks and dual tasks presenting visual stimuli on the optical see-through device, only on a computer screen, and simultaneously on both devices. Results showed that switching between the presentation devices (i.e. perceiving information simultaneously from both devices) produced costs in visual performance. The implications of these costs and of further perceptual and technical factors for mobile gaze-based interaction are discussed and solutions are proposed. 106 urn:nbn:de:gbv:wim2-20121107-17492 10.25643/bauhaus-universitaet.1749 Junior-Professur Psychophysiologie und Wahrnehmung OPUS4-2059 Dissertation Schrader, Kai Hybrid 3D simulation methods for the damage analysis of multiphase composites Modern digital material approaches for the visualization and simulation of heterogeneous materials allow to investigate the behavior of complex multiphase materials with their physical nonlinear material response at various scales. However, these computational techniques require extensive hardware resources with respect to computing power and main memory to solve numerically large-scale discretized models in 3D. Due to a very high number of degrees of freedom, which may rapidly be increased to the two-digit million range, the limited hardware ressources are to be utilized in a most efficient way to enable an execution of the numerical algorithms in minimal computation time. Hence, in the field of computational mechanics, various methods and algorithms can lead to an optimized runtime behavior of nonlinear simulation models, where several approaches are proposed and investigated in this thesis. Today, the numerical simulation of damage effects in heterogeneous materials is performed by the adaption of multiscale methods. A consistent modeling in the three-dimensional space with an appropriate discretization resolution on each scale (based on a hierarchical or concurrent multiscale model), however, still contains computational challenges in respect to the convergence behavior, the scale transition or the solver performance of the weak coupled problems. The computational efficiency and the distribution among available hardware resources (often based on a parallel hardware architecture) can significantly be improved. In the past years, high-performance computing (HPC) and graphics processing unit (GPU) based computation techniques were established for the investigationof scientific objectives. Their application results in the modification of existing and the development of new computational methods for the numerical implementation, which enables to take advantage of massively clustered computer hardware resources. In the field of numerical simulation in material science, e.g. within the investigation of damage effects in multiphase composites, the suitability of such models is often restricted by the number of degrees of freedom (d.o.f.s) in the three-dimensional spatial discretization. This proves to be difficult for the type of implementation method used for the nonlinear simulation procedure and, simultaneously has a great influence on memory demand and computational time. In this thesis, a hybrid discretization technique has been developed for the three-dimensional discretization of a three-phase material, which is respecting the numerical efficiency of nonlinear (damage) simulations of these materials. The increase of the computational efficiency is enabled by the improved scalability of the numerical algorithms. Consequently, substructuring methods for partitioning the hybrid mesh were implemented, tested and adapted to the HPC computing framework using several hundred CPU (central processing units) nodes for building the finite element assembly. A memory-efficient iterative and parallelized equation solver combined with a special preconditioning technique for solving the underlying equation system was modified and adapted to enable combined CPU and GPU based computations. Hence, it is recommended by the author to apply the substructuring method for hybrid meshes, which respects different material phases and their mechanical behavior and which enables to split the structure in elastic and inelastic parts. However, the consideration of the nonlinear material behavior, specified for the corresponding phase, is limited to the inelastic domains only, and by that causes a decreased computing time for the nonlinear procedure. Due to the high numerical effort for such simulations, an alternative approach for the nonlinear finite element analysis, based on the sequential linear analysis, was implemented in respect to scalable HPC. The incremental-iterative procedure in finite element analysis (FEA) during the nonlinear step was then replaced by a sequence of linear FE analysis when damage in critical regions occured, known in literature as saw-tooth approach. As a result, qualitative (smeared) crack initiation in 3D multiphase specimens has efficiently been simulated. 174 urn:nbn:de:gbv:wim2-20131021-20595 10.25643/bauhaus-universitaet.2059 Institut für Strukturmechanik (ISM) OPUS4-3388 Wissenschaftlicher Artikel Areias, Pedro; Rabczuk, Timon; Dias-da-Costa, D.; Piresh, E.B. Implicit solutions with consistent additive and multiplicative components This work describes an algorithm and corresponding software for incorporating general nonlinear multiple-point equality constraints in a implicit sparse direct solver. It is shown that direct addressing of sparse matrices is possible in general circumstances, circumventing the traditional linear or binary search for introducing (generalized) constituents to a sparse matrix. Nested and arbitrarily interconnected multiple-point constraints are introduced by processing of multiplicative constituents with a built-in topological ordering of the resulting directed graph. A classification of discretization methods is performed and some re-classified problems are described and solved under this proposed perspective. The dependence relations between solution methods, algorithms and constituents becomes apparent. Fracture algorithms can be naturally casted in this framework. Solutions based on control equations are also directly incorporated as equality constraints. We show that arbitrary constituents can be used as long as the resulting directed graph is acyclic. It is also shown that graph partitions and orderings should be performed in the innermost part of the algorithm, a fact with some peculiar consequences. The core of our implicit code is described, specifically new algorithms for direct access of sparse matrices (by means of the clique structure) and general constituent processing. It is demonstrated that the graph structure of the second derivatives of the equality constraints are cliques (or pseudo-elements) and are naturally included as such. A complete algorithm is presented which allows a complete automation of equality constraints, avoiding the need of pre-sorting. Verification applications in four distinct areas are shown: single and multiple rigid body dynamics, solution control and computational fracture. 16 Finite Elements in Analysis and Design 15 31 10.1016/j.finel.2012.03.007 Institut für Strukturmechanik (ISM) OPUS4-2760 Konferenzveröffentlichung De Aguinaga, José Guillermo Gürlebeck, Klaus; Lahmer, Tom; Werner, Frank INFLUENCE OF DIFFERENT DATA TYPES FOR THE ESTIMATION OF HYDROMECHANICAL PARAMETERS FOR A WATER RETAINING DAM USING SYNTHETIC DATA The present research analyses the error on prediction obtained under different data availability scenarios to determine which measurements contribute to an improvement of model prognosis and which not. A fully coupled 2D hydromechanical model of a water retaining dam is taken as an example. Here, the mean effective stress in the porous skeleton is reduced due to an increase in pore water pressure under drawdown conditions. Relevant model parameters are ranked by scaled sensitivities, Particle Swarm Optimization is applied to determine the optimal parameter values and model validation is performed to determine the magnitude of error forecast. We compare the predictions of the optimized models with results from a forward run of the reference model to obtain actual prediction errors. The analyses presented here were performed to 31 data sets of 100 observations of varying data types. Calibrating with multiple information types instead of only one sort, brings better calibration results and improvement in model prognosis. However, when using several types of information the number of observations have to be increased to be able to cover a representative part of the model domain; otherwise a compromise between data availability and domain coverage prove best. Which type of information for calibration contributes to the best prognoses, could not be determined in advance. For the error in model prognosis does not depends on the error in calibration, but on the parameter error, which unfortunately can not be determined in reality since we do not know its real value. Excellent calibration fits with parameters' values near the limits of reasonable physical values, provided the highest prognosis errors. While models which included excess pore pressure values for calibration provided the best prognosis, independent of the calibration fit. 12 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170306-27607 10.25643/bauhaus-universitaet.2760 Graduiertenkolleg 1462 OPUS4-2457 Konferenzveröffentlichung Gürlebeck, Klaus; Lahmer, Tom; Werner, Frank International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar The 19th International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering will be held at the Bauhaus University Weimar from 4th till 6th July 2012. Architects, computer scientists, mathematicians, and engineers from all over the world will meet in Weimar for an interdisciplinary exchange of experiences, to report on their results in research, development and practice and to discuss. The conference covers a broad range of research areas: numerical analysis, function theoretic methods, partial differential equations, continuum mechanics, engineering applications, coupled problems, computer sciences, and related topics. Several plenary lectures in aforementioned areas will take place during the conference. We invite architects, engineers, designers, computer scientists, mathematicians, planners, project managers, and software developers from business, science and research to participate in the conference! 434 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20150916-24571 10.25643/bauhaus-universitaet.2457 Professur Stahlbau