TY - CHAP A1 - Sikiwat, Tanongsak A1 - Breidt, Michael A1 - Hartmann, Dietrich ED - Gürlebeck, Klaus ED - Könke, Carsten T1 - COMPUTATIONAL STEERING FOR COLLAPSE SIMULATION OF LARGE SCALE COMPLEX STRUCTURES N2 - In order to model and simulate collapses of large scale complex structures, a user-friendly and high performance software system is essential. Because a large number of simulation experiments have to be performed, therefore, next to an appropriate simulation model and high performance computing, efficient interactive control and visualization capabilities of model parameters and simulation results are crucial. To this respect, this contribution is concerned with advancements of the software system CADCE (Computer Aided Demolition using Controlled Explosives) that is extended under particular consideration of computational steering concepts. Thereby, focus is placed on problems and solutions for the collapse simulation of real world large scale complex structures. The simulation model applied is based on a multilevel approach embedding finite element models on a local as well as a near field length scale, and multibody models on a global scale. Within the global level simulation, relevant effects of the local and the near field scale, such as fracture and failure processes of the reinforced concrete parts, are approximated by means of tailor-made multibody subsystems. These subsystems employ force elements representing nonlinear material characteristics in terms of force/displacement relationships that, in advance, are determined by finite element analysis. In particular, enhancements concerning the efficiency of the multibody model and improvements of the user interaction are presented that are crucial for the capability of the computational steering. Some scenarios of collapse simulations of real world large scale structures demonstrate the implementation of the above mentioned approaches within the computational steering. KW - Angewandte Informatik KW - Angewandte Mathematik KW - Architektur KW - Computerunterstütztes Verfahren KW - Computer Science Models in Engineering; Multiscale and Multiphysical Models; Scientific Computing Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-28908 UR - http://euklid.bauing.uni-weimar.de/ikm2009/paper.html SN - 1611-4086 ER - TY - CHAP A1 - Knabe, Tina ED - Gürlebeck, Klaus ED - Könke, Carsten T1 - CONSTITUTIVE MODELS FOR SUBSOIL IN THE CONTEXT OF STRUCTURAL ANALYSIS IN CONSTRUCTION ENGINEERING N2 - Parameters of constitutive models are obtained generally comparing the results of forward numerical simulations to measurement data. Mostly the parameter values are varied by trial-and-error in order to reach an improved fit and obtain plausible results. However, the description of complex soil behavior requires advanced constitutive models where the rising complexity of these models mainly increases the number of unknown constitutive parameters. Thus an efficient identification "by hand" becomes quite difficult for most practical geotechnical problems. The main focus of this article is on finding a vector of parameters in a given search space which minimizes discrepancy between measurements and the associated numerical result. Classically, the parameter values are estimated from laboratory tests on small samples (triaxial tests or oedometer tests). For this purpose an automatic population-based approach is present to determine the material parameters for reconstituted and natural Bothkennar Clay. After the identification a statistical assessment is carried out of numerical results to evaluate different constitutive models. On the other side a geotechnical problem, stone columns under an embankment, is treated in a well instrumented field trial in Klagenfurt, Austria. For the identification purpose there are measurements from multilevel-piezometers, multilevel-extensometers and horizontal inclinometer. Based on the simulation of the stone columns in a FE-Model the identification of the constitutive parameters is similar to the experimental tests by minimizing the absolute error between measurement and numerical curves. KW - Angewandte Informatik KW - Angewandte Mathematik KW - Architektur KW - Computerunterstütztes Verfahren KW - Computer Science Models in Engineering; Multiscale and Multiphysical Models; Scientific Computing Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-28628 UR - http://euklid.bauing.uni-weimar.de/ikm2009/paper.html SN - 1611-4086 ER - TY - CHAP A1 - Fröbel, Toni A1 - Firmenich, Berthold A1 - Koch, Christian ED - Gürlebeck, Klaus ED - Könke, Carsten T1 - COUPLING PATTERNS IN CIVIL ENGINEERING APPLICATIONS N2 - Buildings can be divided into various types and described by a huge number of parameters. Within the life cycle of a building, especially during the design and construction phases, a lot of engineers with different points of view, proprietary applications and data formats are involved. The collaboration of all participating engineers is characterised by a high amount of communication. Due to these aspects, a homogeneous building model for all engineers is not feasible. The status quo of civil engineering is the segmentation of the complete model into partial models. Currently, the interdependencies of these partial models are not in the focus of available engineering solutions. This paper addresses the problem of coupling partial models in civil engineering. According to the state-of-the-art, applications and partial models are formulated by the object-oriented method. Although this method solves basic communication problems like subclass coupling directly it was found that many relevant coupling problems remain to be solved. Therefore, it is necessary to analyse and classify the relevant coupling types in building modelling. Coupling in computer science refers to the relationship between modules and their mutual interaction and can be divided into different coupling types. The coupling types differ on the degree by which the coupled modules rely upon each other. This is exemplified by a general reference example from civil engineering. A uniform formulation of coupling patterns is described analogously to design patterns, which are a common methodology in software engineering. Design patterns are templates for describing a general reusable solution to a commonly occurring problem. A template is independent of the programming language and the operating system. These coupling patterns are selected according to the specific problems of building modelling. A specific meta-model for coupling problems in civil engineering is introduced. In our meta-model the coupling patterns are a semantic description of a specific coupling design. KW - Angewandte Informatik KW - Angewandte Mathematik KW - Architektur KW - Computerunterstütztes Verfahren KW - Computer Science Models in Engineering; Multiscale and Multiphysical Models; Scientific Computing Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-28443 UR - http://euklid.bauing.uni-weimar.de/ikm2009/paper.html SN - 1611-4086 ER - TY - CHAP A1 - Siekierski, Wojciech ED - Gürlebeck, Klaus ED - Könke, Carsten T1 - CRITICAL STRESS ASSESSMENT IN ANGLE TO GUSSET PLATE BOLTED CONNECTION BY SIMPLIFIED FEM MODELLING N2 - Simplified modelling of friction grip bolted connections of steel member – to – gusset plate is often applied in engineering practise. The paper deals with the simplification of pre-tensioned bolt model and simplification of load transfer within connection. Influence on normal strain (and thus stress) distribution at critical cross-section is investigated. Laboratory testing of single-angle or double-angle members – to – gusset plates bolted connections were taken as basis for numerical analysis. FE models were created using 1D and 2D elements. Angles and gusset plates were modelled with shell elements. Two methods of modelling of friction grip bolting were considered: bolt-regarding approach with 1D element systems modelling bolts and two variants of bolt-disregarding approach with special constraints over some part of member and gusset plate surfaces in contact: a) constraints over whole area of contact, b) constraints over the area around each bolt shank (“partially tied”). Modelling of friction grip bolted connections using simplified bolt modelling may be effective, especially in the case of analysis concerning elastic range only. In such a case disregarding bolts and replacing them with “partially tied” modelling seems to be more attractive. It is less time-consuming and provides results of similar accuracy in comparison to analysis utilizing simplified bolt modelling. KW - Angewandte Informatik KW - Angewandte Mathematik KW - Architektur KW - Computerunterstütztes Verfahren KW - Computer Science Models in Engineering; Multiscale and Multiphysical Models; Scientific Computing Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-28897 UR - http://euklid.bauing.uni-weimar.de/ikm2009/paper.html SN - 1611-4086 ER - TY - THES A1 - Gorski, Michael T1 - Cryptanalysis and Design of Symmetric Primitives N2 - Der Schwerpunkt dieser Dissertation liegt in der Analyse und dem Design von Block- chiffren und Hashfunktionen. Die Arbeit beginnt mit einer Einführung in Techniken zur Kryptoanalyse von Blockchiffren. Wir beschreiben diese Methoden und zeigen wie man daraus neue Techniken entwickeln kann, welche zu staerkeren Angriffen fuehren. Im zweiten Teil der Arbeit stellen wir eine Reihe von Angriffen auf eine Vielzahl von Blockchiffren dar. Wir haben dabei Angriffe auf reduzierte Versionen von ARIA und dem AES entwickelt. Darueber hinaus praesentieren wir im dritten Teil Angriffe auf interne Blockchiffren von Hashfunktionen. Wir entwickeln Angriffe, welche die inter- nen Blockchiffren von Tiger und HAS-160 auf volle Rundenanzahl brechen. Die hier vorgestellten Angriffe sind die ersten dieser Art. Ein Angriff auf eine reduzierte Ver- sion von SHACAL-2 welcher fast keinen Speicherbedarf hat, wird ebenfalls vorgestellt. Der vierte Teil der Arbeit befasst sich mit den Design und der Analyse von kryp- tographischen Hashfunktionen. Wir habe einen Slide Angriff, eine Technik welche aus der Analyse von Blockchiffren bekannt ist, im Kontext von Hashfunktionen zur Anwendung gebracht. Dabei praesentieren wir verschiedene Angriffe auf GRINDAHL und RADIOGATUN. Aufbauend auf den Angriffen des zweiten und dritten Teils dieser Arbeit stellen wir eine neue Hashfunktion vor, welche wir TWISTER nennen. TWISTER wurde fuer den SHA-3 Wettbewerb entwickelt und ist bereits zur ersten Runde angenommen. N2 - This thesis focuses on the cryptanalysis and the design of block ciphers and hash func- tions. The thesis starts with an overview of methods for cryptanalysis of block ciphers which are based on differential cryptanalysis. We explain these concepts and also sev- eral combinations of these attacks. We propose new attacks on reduced versions of ARIA and AES. Furthermore, we analyze the strength of the internal block ciphers of hash functions. We propose the first attacks that break the internal block ciphers of Tiger, HAS-160, and a reduced round version of SHACAL-2. The last part of the thesis is concerned with the analysis and the design of cryptographic hash functions. We adopt a block cipher attack called slide attack into the scenario of hash function cryptanalysis. We then use this new method to attack different variants of GRINDAHL and RADIOGATUN. Finally, we propose a new hash function called TWISTER which was designed and pro- posed for the SHA-3 competition. TWISTER was accepted for round one of this com- petition. Our approach follows a new strategy to design a cryptographic hash function. We also describe several attacks on TWISTER and discuss the security issues concern- ing these attack on TWISTER. T2 - Kryptoanalyse und Design von symmetrischen Primitiven KW - Differentielle Kryptoanalyse KW - Kryptoanalyse KW - Advanced Encryption Standard KW - Hash-Algorithmus KW - Blockchiffre KW - Kryptologie KW - SHACAL-2 KW - HAS-160 KW - Tiger KW - ARIA KW - slide attacks KW - Grindahl KW - RadioGatun KW - differential cryptanalysis KW - hash function KW - block ciphers KW - slide attacks KW - HAS-160 KW - ARIA KW - AES-192 KW - AES-256 KW - Tiger KW - Grindahl KW - RadioGatun Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20101130-15267 ER - TY - GEN A1 - Theiler, Michael T1 - Documentation and conceptual development of software components for the execution of geometric Boolean set operations on the basis of Java3D N2 - Complex buildings and other structures are cumulatively planned with software that supports the export of building information in the STEP-format on the basis of the IFC (Industry Foundation Classes). Because of the availability of this interface, it is possible to use the data of a building for further processing. Within the IFC, several geometrical models for the visualization of building elements are provided. Among others, geometric Boolean set operations are needed to "subtract" openings from building elements (e.g. for windows or doors) - CSG (Constructive Solid Geometry). Therefore, software components based on the algorithms [Laidlaw86] and [Hubbard90] were developed at the professorship Informatik im Bauwesen that support these functionalities on the basis of Java3D. However, it turned out in praxis, that these components are numerically instable and that there is no acceptable robustness or tolerance of errors. This is caused by mistakes in the implementation (bugs) as well as the insufficient handling of numerical inaccuracies. Further, a verification and, where applicable, a correction of qualitative substandard initial data is missing. Prior to this student research project, the implementation of a self-contained application for a visual error control was initiated. This tool visualizes several program steps and their corresponding data. With use of this tool, the implemented algorithms can be analyzed in detail. The papers [Laidlaw86] and [Hubbard90] are unsatisfactory describing some essential steps of the algorithm as well as implementation details to execute Boolean set operations on the basis of a B-rep (Boundary Representation) model. Hence, the algorithm should be documented comprehensible with the help of figures and pseudo code. Moreover, problems within the existing implementation shall be identified and possible solution strategies shall be provided. KW - Boolean Operations Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20130603-19430 ER - TY - GEN A1 - Ballerstedt, Stefanie A1 - Beccu, Annelie A1 - Büttner, Theres A1 - Friedmann, Christin A1 - Korritke, Constanze A1 - Kuppler, Jana A1 - Winzer, Sandra A1 - Zigahn, Britta A1 - Cheng, Jin A1 - Cheynel, Mary A1 - Ciabrini, Charlotte A1 - Deligny, Céline A1 - Köneke, Sarah A1 - Martin, Anna A1 - Hernandez, Catherine Mirallas A1 - Neubauer, Tanja A1 - Riesch, Sarah A1 - Bartling, Inga A1 - Dreßig, Sandra A1 - Gröne, Sarah A1 - Kloth, Daniela A1 - Reuter, Mika A1 - Sandtner, Lisa A1 - Sänger, Tom A1 - Schauer, Christine A1 - Stegmann, Markus A1 - Wasserek, Moritz T1 - E-Book : Ergebnisse aus der digitalen Forschungswerkstatt T1 - E-Book : Research findings from the digital factory N2 - Digitale Lesezeichen, Volltextsuche und Multimedia-Inhalte – die Ende des 20. Jahrhunderts durch das Internet ausgelöste Medienrevolution ließ auch das Buch nicht unberührt. Die Verbreitung des World Wide Webs parallel zur rasanten Entwicklung der Computertechnologie ermöglichte die Digitalisierung des Buches und bildete das E-Book als neue Publikationsform heraus. Seit etwa zehn Jahren können Bücher nicht mehr nur gedruckt, sondern auch elektronisch zur Verfügung gestellt werden, was für die Buchbranche und den Leser einige Veränderungen bedeutet. Moderne Lesegeräte, auch E-Reader genannt, erlauben die Speicherung einer ganzen Bibliothek auf einem einzigen mobilen Endgerät. Dabei steht das einzelne E-Book dem gedruckten Buch in seiner Lesequalität in nichts nach und ermöglicht zudem das Einfügen elektronischer Notizen und Lesezeichen, die Volltextsuche nach bestimmten Wörtern und die Verbindung von Text mit Bild, Ton und Video. Dennoch kann das E-Book seit seinem Aufkommen in Deutschland noch keine Erfolgsgeschichte schreiben. Insbesondere hohe Preise für die Lesegeräte halten immer noch viele Leser vom Nutzen der E-Books ab. Zu sehr ist das gedruckte Buch für zahlreiche Menschen noch fester Bestandteil ihres alltäglichen Lebens, als das sie es bereits durch das E-Book austauschen würden. Eine Situation, die einige Fragen aufwirft: Wird sich das EBook als Medium durchsetzen und das gedruckte Buch langfristig ablösen? Kann das EBook neben Zeitung, Radio, Fernsehen und Buch überhaupt als ein neues Medium verstanden werden? Und welche Veränderungen würde die massenhafte Verbreitung elektronischer Bücher mit sich bringen? KW - Elektronisches Buch KW - Leseverhalten KW - Verlag KW - Bibliothek KW - Wertschöpfung KW - Marktstruktur KW - E-Book Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20110418-15455 ER - TY - THES A1 - Nguyen, Quang Minh T1 - Ein Konzept für ökologischen Siedlungsbau in Hanoi und seiner Umgebung am Beispiel der Siedlung Phung Khoang N2 - Der Siedlungsbau in Hanoi kan heutzutage - über 20 Jahre nach dem Beginn der Renovierungspolitik udn der Markwirtschaft, die dem Städtebau eine große Gelegenheit zur Verbesserung gegeben haben - zurückblickend und eingeschätz werden. Die letzten 20 Jahre sind eine kurze Zeit in der tausendjährigen Geschichte der Stadt, trotzdem entwickelte sich die Stadt in diesem Zeitraum am schnellsten und auch am problematischten aus Sicht der Umwelt. Ohne eine passende Entwicklungsstategie oder eine geeignete Maßnahme bei der Stadtplanung vergrößert sich der Konflikt Ökonomie - Ökologie immer weiter. ... Die Findung eines neuen Wohnkonzeptes im Gleichgewicht zwischen Ökonomie und der Ökologie ist eine hochaktuelle Frage geworden. N2 - The climat change, the enlargement of the ozone hole, the destruction of forests, the desertification and the other negative effects, which are cused by human daily activities, become global issues. However, they are particularly serous in developing and newly industialized countries. Vietnam has to face such problems as well. Under this circumstance, human beings are both offenders and victims. Environment-friendly or not? Economy with or without ecology? As living dreatures in nature human beings must answer these questions themselves and react on these challenge in time. KW - Siedlung KW - Städtebau KW - Bauökologie KW - Siedlungsbau KW - Hanoi KW - Phung Khoang KW - ecological architecture KW - urban planning KW - urban building Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20100902-15183 ER - TY - GEN A1 - Marschetzky, Henrik T1 - Energie-basierte Auslegung von Tragsystemen für Hochhäuser in Abhängigkeit von der Größenordnung N2 - Angelehnt an Entwicklungen des aktuellen Hochhausbaus, die Gebäudehöhen von über 600 m vorsehen, behandelt die vorliegende Arbeit Möglichkeiten der Konzeption von Aussteifungssystemen. Ein ausgewähltes Tragwerk aus Stahlbetonschubwänden und einer Höhe von 800 m wird mit der 3D-Analyse-Software ETABS (Version 9.0.9) bemessen. Dieses Tragwerk wird mit extremen Einwirkungen infolge Wind und Erdbeben belastet. Da ein solch hohes Gebäude außerhalb der Anwendungsgrenzen internationaler Normen liegt, wird ein eigener Ansatz für den Lastfall Wind zur Analyse des Schwingungsverhaltens gewählt. Aufbauend auf den Ergebnissen der Analyse werden Möglichkeiten der Reduktion bzw. Dämpfung von kritischen Gebäudeschwingungen diskutiert. Die konkrete Dämpfungsvariante „Passiver Schwingungsdämpfer“ (Tuned Mass Damper) wird, unter Verwendung von Optimierungskriterien, in ETBAS modelliert und in die Berechnungen eingebunden. Dieses Tragwerk wird zwei kleineren Tragwerken (H = 200 m bzw. 400 m) gegenübergestellt und mittels dem MIPS-Konzept (Material-Input pro Serviceeinheit) analysiert. Ziel ist es dabei, qualitative Aussagen zur Nachhaltigkeit und ökologischer Effizienz besonders hoher Gebäude zu treffen. KW - Hochhaus KW - Tragsystem KW - Schwingungsdämpfer KW - Etabs KW - Tuned Mass Damper KW - TMD KW - MIPS-Konzept KW - Ressourcenanalyse Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20101011-15224 ER - TY - CHAP A1 - Eckardt, Stefan A1 - Könke, Carsten ED - Gürlebeck, Klaus ED - Könke, Carsten T1 - ENERGY RELEASE CONTROL FOR NONLINEAR MESOSCALE SIMULATIONS N2 - In nonlinear simulations the loading is, in general, applied in an incremental way. Path-following algorithms are used to trace the equilibrium path during the failure process. Standard displacement controlled solution strategies fail if snap-back phenomena occur. In this contribution, a path-following algorithm based on the dissipation of the inelastic energy is presented which allows for the simulation of snap-backs. Since the constraint is defined in terms of the internal energy, the algorithm is not restricted to continuum damage models. Furthermore, no a priori knowledge about the final damage distribution is required. The performance of the proposed algorithm is illustrated using nonlinear mesoscale simulations. KW - Angewandte Informatik KW - Angewandte Mathematik KW - Architektur KW - Computerunterstütztes Verfahren KW - Computer Science Models in Engineering; Multiscale and Multiphysical Models; Scientific Computing Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-28414 UR - http://euklid.bauing.uni-weimar.de/ikm2009/paper.html SN - 1611-4086 ER -