TY  - JOUR
A1  - Bucher, Christian
A1  - Most, Thomas
T1  - A comparison of approximate response functions in structural reliability analysis
JF  - Probabilistic Engineering Mechanics
N2  - A comparison of approximate response functions in structural reliability analysis
KW  - Angewandte Mathematik
KW  - Strukturmechanik
Y1  - 2008
SP  - 154
EP  - 163
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  - Beer, Daniel G.
A1  - Firmenich, Berthold
A1  - Richter, Torsten
T1  - A Concept for CAD Systems with Persistent Versioned Data Models
N2  - The synchronous distributed processing of common source code in the software development process is supported by well proven methods. The planning process has similarities with the software development process. However, there are no consistent and similarly successful methods for applications in construction projects. A new approach is proposed in this contribution.
KW  - Produktmodell
KW  - Bautechnik
KW  - Forschungskooperation
KW  - Versionsverwaltung
KW  - CAD
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2046
ER  - 
TY  - CHAP
A1  - Al Diab, Ali
A1  - Henry, Eric
A1  - Boulemia, Cherif
T1  - A concerted and multi-criterion approach for helping to choose a Structure- Foundation system of building
N2  - The research of the best building design requires a concerted design approach of both structure and foundation. Our work is an application of this approach. Our objective is also to create an interactive tool, which will be able to define, at the early design stages, the orientations of structure and foundation systems that satisfy as well as possible the client and the architect. If the concerns of these two actors are primarily technical and economical, they also wish to apprehend the environmental and social dimensions of their projects. Thus, this approach bases on alternative studies and on a multi-criterion analysis. In this paper, we present the context of our work, the problem formulation, which allows a concerted design of Structure and Foundation systems and the feasible solutions identifying process.
KW  - Bauwerk
KW  - Gründung
KW  - CAD
KW  - Entscheidung bei mehrfacher Zielsetzung
KW  - Early design stage
KW  - building
KW  - foundation
KW  - multi-criterion analysis
KW  - decision making
Y1  - 2003
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2732
ER  - 
TY  - CHAP
A1  - Bock, Sebastian
A1  - Gürlebeck, Klaus
ED  - Gürlebeck, Klaus
ED  - Könke, Carsten
T1  - A Coupled Ritz-Galerkin Approach Using Holomorphic and Anti-holomorphic Functions
N2  - The contribution focuses on the development of a basic computational scheme that provides a suitable calculation environment for the coupling of analytical near-field solutions with numerical standard procedures in the far-field of the singularity. The proposed calculation scheme uses classical methods of complex function theory, which can be generalized to 3-dimensional problems by using the framework of hypercomplex analysis. The adapted approach is mainly based on the factorization of the Laplace operator EMBED Equation.3 by the Cauchy-Riemann operator EMBED Equation.3 , where exact solutions of the respective differential equation are constructed by using an orthonormal basis of holomorphic and anti-holomorphic functions.
KW  - Architektur <Informatik>
KW  - CAD
KW  - Computerunterstütztes Verfahren
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170327-29281
UR  - http://euklid.bauing.uni-weimar.de/ikm2006/index.php_lang=de&what=papers.html
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  - 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  - Alalade, Muyiwa
A1  - Reichert, Ina
A1  - Köhn, Daniel
A1  - Wuttke, Frank
A1  - Lahmer, Tom
ED  - Qu, Chunxu
ED  - Gao, Chunxu
ED  - Zhang, Rui
ED  - Jia, Ziguang
ED  - Li, Jiaxiang
T1  - A Cyclic Multi-Stage Implementation of the Full-Waveform Inversion for the Identification of Anomalies in Dams
JF  - Infrastructures
N2  - For the safe and efficient operation of dams, frequent monitoring and maintenance are required. These are usually expensive, time consuming, and cumbersome. To alleviate these issues, we propose applying a wave-based scheme for the location and quantification of damages in dams.
To obtain high-resolution “interpretable” images of the damaged regions, we drew inspiration from non-linear full-multigrid methods for inverse problems and applied a new cyclic multi-stage full-waveform inversion (FWI) scheme. Our approach is less susceptible to the stability issues faced by the standard FWI scheme when dealing with ill-posed problems. In this paper, we first selected an optimal acquisition setup and then applied synthetic data to demonstrate the capability of our approach in identifying a series of anomalies in dams by a mixture of reflection and transmission tomography. The results had sufficient robustness, showing the prospects of application in the field of non-destructive testing of dams.
KW  - Damm
KW  - Defekt
KW  - inverse analysis
KW  - damage identification
KW  - full-waveform inversion
KW  - dams
KW  - wave propagation
KW  - OA-Publikationsfonds2022
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20221201-48396
UR  - https://www.mdpi.com/2412-3811/7/12/161
VL  - 2022
IS  - Volume 7, issue 12, article 161
PB  - MDPI
CY  - Basel
ER  - 
TY  - THES
A1  - Lux, Christopher
T1  - A Data-Virtualization System for Large Model Visualization
N2  - Interactive scientific visualizations are widely used for the visual exploration and examination of physical data resulting from measurements or simulations. Driven by technical advancements of data acquisition and simulation technologies, especially in the geo-scientific domain, large amounts of highly detailed subsurface data are generated. The oil and gas industry is particularly pushing such developments as hydrocarbon reservoirs are increasingly difficult to discover and exploit. Suitable visualization techniques are vital for the discovery of the reservoirs as well as their development and production. However, the ever-growing scale and complexity of geo-scientific data sets result in an expanding disparity between the size of the data and the capabilities of current computer systems with regard to limited memory and computing resources.


In this thesis we present a unified out-of-core data-virtualization system supporting geo-scientific data sets consisting of multiple large seismic volumes and height-field surfaces, wherein each data set may exceed the size of the graphics memory or possibly even the main memory. Current data sets fall within the range of hundreds of gigabytes up to terabytes in size. Through the mutual utilization of memory and bandwidth resources by multiple data sets, our data-management system is able to share and balance limited system resources among different data sets. We employ multi-resolution methods based on hierarchical octree and quadtree data structures to generate level-of-detail working sets of the data stored in main memory and graphics memory for rendering. The working set generation in our system is based on a common feedback mechanism with inherent support for translucent geometric and volumetric data sets. This feedback mechanism collects information about required levels of detail during the rendering process and is capable of directly resolving data visibility without the application of any costly occlusion culling approaches. A central goal of the proposed out-of-core data management system is an effective virtualization of large data sets. Through an abstraction of the level-of-detail working sets, our system allows developers to work with extremely large data sets independent of their complex internal data representations and physical memory layouts.


Based on this out-of-core data virtualization infrastructure, we present distinct rendering approaches for specific visualization problems of large geo-scientific data sets. We demonstrate the application of our data virtualization system and show how multi-resolution data can be treated exactly the same way as regular data sets during the rendering process. An efficient volume ray casting system is presented for the rendering of multiple arbitrarily overlapping multi-resolution volume data sets. Binary space-partitioning volume decomposition of the bounding boxes of the cube-shaped volumes is used to identify the overlapping and non-overlapping volume regions in order to optimize the rendering process. We further propose a ray casting-based rendering system for the visualization of geological subsurface models consisting of multiple very detailed height fields. The rendering of an entire stack of height-field surfaces is accomplished in a single rendering pass using a two-level acceleration structure, which combines a minimum-maximum quadtree for empty-space skipping and sorted lists of depth intervals to restrict ray intersection searches to relevant height fields and depth ranges. Ultimately, we present a unified rendering system for the visualization of entire geological models consisting of highly detailed stacked horizon surfaces and massive volume data. We demonstrate a single-pass ray casting approach facilitating correct visual interaction between distinct translucent model components, while increasing the rendering efficiency by reducing processing overhead of potentially invisible parts of the model. The combination of image-order rendering approaches and the level-of-detail feedback mechanism used by our out-of-core data-management system inherently accounts for occlusions of different data types without the application of costly culling techniques.


The unified out-of-core data-management and virtualization infrastructure considerably facilitates the implementation of complex visualization systems. We demonstrate its applicability for the visualization of large geo-scientific data sets using output-sensitive rendering techniques. As a result, the magnitude and multitude of data sets that can be interactively visualized is significantly increased compared to existing approaches.
KW  - Computer Graphics
KW  - Visualisation
KW  - Volume Rendering
KW  - Large Data
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20130725-19855
ER  - 
TY  - THES
A1  - Hanko, Johanne
T1  - A decision-making tool for the selection of an appropriate integrated MSW management system for tropical Asian cities; the case of Bangkok
N2  - Einführung Tropische asiatische Entwicklungs- und Schwellenländer zeigten rasches städtisches Wachstum dadurch, dass Bauern einwanderten, um ein besseres Leben in der Stadt zu suchen. Dadurch ergab sich in vielen Städten ein Mangel an geeigneter Infrastruktur und an sozialen Diensten. Die städtische Müllversorgung bildet keine Ausnahme; sie wird sogar oft an das Ende der Prio-ritätenliste für städtische Aufgabenpläne gestellt, da dabei zuerst die Gesetze und Verordnun-gen formuliert und umgesetzt werden müssen. Das Problem des nicht entsorgten städtischen Mülls führt (mit Sicherheit) zu Luftverschmutzung, Krankheit und zur Verseuchung des Bo-dens und des Wassers. Diese Probleme stehen in tropischen Klimaten im Zusammenhang mit hoher Temperatur und Feuchtigkeit, mit heftigem Regen und mit häufigen Überschwemmun-gen. Stehendes Wasser und Ausschwemmung aus dem Abfall werden sehr schnell zu Brutstät-ten von Insekten, Nagern und Bakterien, und damit zu einer Gesundheitsgefahr für Arbeiter und die allgemeine Bevölkerung. Darüber hinaus kann Wasser- und Grundwasserverschmut-zung/Kontamination zu einer ernsten Umweltzerstörung führen, mit direkten Auswirkungen auf die Wasserressourcen, und auf raschen Qualitätsverlust der pflanzlichen Erzeugnisse, des Rückgrates der meisten tropischen asiatischen Länder. Müllentsorgung und die Verantwortlichkeiten Lokale Regierungen müssen die öffentliche Gesundheit ihrer lokalen Bevölkerung sicherstellen und sind deshalb für die Müllentsorgung verantwortlich. Asiatische tropische Klimate sich rasch ändernde Müllzusammensetzung machen die Müllbehandlung und –entsorgung zu einer dauernden Herausforderung der Entscheidungsträger. Vor einer Entscheidung über das ver-wendete Entsorgungssystem muss eine geeignete Abfall-Charakterisierung treten. Diese Cha-rakterisierung liefert Kenntnisse über die Abfallmenge, die Feuchte, den Heizwert und die Menge der verschiedenen Komponenten im Abfallstrom, wie z. B.: organisches Material, Plas-tik, Papier, Karton, Holz, Textilien, Gummi, Leder, Glas, Metalle, Nichtmetalle, Steine und Keramiken. Darüber hinaus ist die Herausforderung, der sich asiatische Länder gegenüber se-hen, ein Mangel an Raum und damit wird die Platzierung eine Deponie zunehmend schwierig. Die Abfallwirtschaft ist eine kostenintensive, aber trotzdem notwendige Maßnahme, um das Wohlergehen sowohl der Bevölkerung als auch für die Umwelt sicher zu stellen. Es wird ge-schätzt, dass Asien im Jahr 2025 etwa 47 Milliarden US$ aufwenden muss, um 0,5 bis 1 Kg städtischen Müll je Person und Tag abzufahren und zu behandeln, oder 5 US$ je Kopf und Jahr. In Entwicklungsländern sind unzählige Leute nicht in der Lage, diese hohen Preise für die Ab-fallentsorgung zu zahlen. Deshalb liegt es in der Verantwortung der Regierung, die Abfallent-sorgung zu betreiben und zu finanzieren, um die Bevölkerung, die Gemeinde und die Umwelt zu schützen. Tropische asiatische Städte müssen jetzt bezahlbare und nachhaltige Verfahren für die Entsorgung ihrer zunehmenden Menge täglichen Abfalls benennen, wobei gleichzeitig auf minimale Umweltbelastung, auf soziale Akzeptanz und auf minimale Landverbrauch zu achten ist. Eine leicht anwendbare Entscheidungshilfe zur Wahl des geeignetesten Abfallbehandlungs-system der Gemeinde wäre deshalb sehr nützlich. Proposition Der Zweck dieser Dissertation war die Entwicklung eines nutzerfreundlichen Instrumentariums für das Verwaltungs- und Regierungspersonal in tropischen Entwicklungs- und Schwellenlän-der. 1. Diese Vorgehensweise basiert auf einem Netzwerk, das eine Liste ausgewählter entschei-dungsrelevanter Tatsachen in Betracht zieht, die nötig sind, um eine informierte Entschei-dung machen zu können. Das entscheidungshelfende Verfahren muss von Entscheidungs-trägern bei einer vorläufigen Feststellung des Abfallentsorgungs- und -behandlungssystems für ihre Gemeinde benutzt werden. 2. Tropische asiatische Städte müssen eine Reihe von Faktoren berücksichtigen, wenn sie über ihren Abfallwirtschaftsplan entscheiden. Dazu gehören die immerwechselnde Menge und Zusammensetzung des Abfalls infolge der zunehmenden Bevölkerungszahl und des Ein-kommens je Kopf, der hohe Feuchtigkeitsgrad, Verbrennungswärme-Werte und die oft be-grenzten finanziellen Möglichkeiten. 3. Ferner sind gesetzliche, politische, verwaltungstechnische, soziale, finanzielle, ökonomi-sche und technische Faktoren bestimmend. 4. Die Verwaltung muss dabei die Wichtigkeit jedes Teilschrittes der Abfallwirtschaft im Au-ge behalten, also Abfallerzeugung, Sammlung, Transport, Abfallcharakterisierung, Entsor-gung und Behandlung. 5. Die Rolle der lokalen Gemeinden in der Entscheidungsfindung ist nicht hoch genug einzu-schätzen; deshalb müssen Mitglieder der Gemeinde aktiv am Schutz der Umwelt und an der Verhinderung ihrer Zerstörung mitwirken. Mehrere Entscheidungshilfsverfahren für ver-schiedene Anwendungen wurden entwickelt. Jedoch zieht die Mehrzahl von ihnen nicht notwendigerweise eine öffentliche Teilnahme in Betracht, und sie sind auch nicht benutzer-freundlich. 6. Um die Komplexität der Probleme besser zu verstehen, die bei tropischen asiatischen Städ-ten auftreten, wurde die Innenstadt von Bangkok, Thailands größte Stadt und Hauptstadt, als repräsentativer Fall ausgewählt, für die Entsorgung der 9000 t Müll der täglich produ-ziert wird. Thailands Klima ist, besonders während der jährlichen Monsunzeit, heiß und feucht mit einer mittleren Temperatur von 28,4°C und einer Feuchtigkeit zwischen 70 und 100%. Die Gesetze und Verordnungen zeigen sehr deutlich an, wie wichtig die Behandlung des städtischen Abfalls genommen wird. Zahlreiche Interviews, verbunden mit der Durch-sicht von Dokumenten, Berichten und Ortsbesichtigungen ergaben Kenntnisse der zahlrei-chen Entscheidungsmaßnahmen, denen sich die städtischen Entscheidungsträger einer tro-pischen Stadt gegenüber sehen. Die Durchsicht und die Analyse der Entscheidungsmaß-nahmen in Bangkoks Abfallentsorgungsstrategien zeigten, wie das Entscheiden als Werk-zeug in verschiedenen asiatischen tropischen Städten benutzt werden kann. 7. Ein Entscheidungsrahmen wurde erstellt auf der Grundlage von Literatur-Recherchen und persönliche Erfahrungen, und anhand der in der Stadt Bangkok gesammelte Daten über-prüft. Die Entscheidungspunkte im Netzwerk umfassen eine allgemeine Beschreibung der Stadt, ihre klimatischen und hydrogeologischen Bedingungen, die Menge und Art des er-zeugten Mülls, einen Überblick über die bestehenden Anlagen und die existierenden Pro-gramme, öffentliche Aufmerksamkeit zu gewinnen, den sozioökonomischen Aspekt eines Abfallbehandlungssystems und die öffentliche Teilnahme. Es berücksichtigt ferner Ge-sundheits- und Sicherheitsüberlegungen im Zusammenhang mit Abfallentsorgungsmög-lichkeiten und ihrer Kosten. 8. Das Entscheidungsinstrumentarium hat als Ziel, ein geeignetes Abfallbehandlungssystem zu ermöglichen, das als Grundlage soziale, klimatische und technische Informationen be-nutzt. Ihre Einfachheit erlaubt einem Verwaltungspersonal, das wenig Erfahrung mit Ab-fallwirtschaft und Computerwissen besitzt, verschiedene Optionen zu analysieren und Sze-narien auszutesten. Des weiteren werden verschiedene Möglichkeiten überprüft, und es wird versucht, die Optionen in die Abfallwirtschaft zu integrieren. 9. Das Instrumentarium beinhaltet über ein Hundert geschlossene Fragen, die auf das Analy-sieren der Bedürfnisse und der gegenwärtigen Situation der Abfallwirtschaft einer be-stimmten Gesellschaft ausgerichtet sind und die es ermöglichen, ein geeignetes Abfallwirt-schaftssystem für die entsprechende Gesellschaft zu wählen. Diese Fragen hatten als Grundlage die Rahmen und Eckpunkte des Entscheidungsinstrumentariums. Dieses Instru-mentarium ist selbsterklärend, und gleichzeitig bietet es Flexibilität bei der Entscheidung, um wie viel Prozent des Abfalls wieder verwertet wird, kompostiert oder behandelt durch irgend eine von den sechs Behandlungsoptionen; Kompostierung, Vergärung, nicht-Verbrennungssysteme, Verbrennung, Deponierung und Energiegewinnung. 10. Die Ziele eines integrierten Abfallwirtschaftssystems können vom Benutzer geändert und modifiziert werden. Dies ermöglicht die Überprüfung verschiedener Szenarien und die Auswahl des geeignetesten Abfallbehandlungssystems. Das System kann sehr einfach sein und nur ein Behandlungssystem beinhalten oder mit einer Auswahl mehrere Behandlungs-systeme sehr kompliziert sein. In einigen Ländern ist es Vorschrift mehrere Systeme anzu-wenden. Integrierte Abfallwirtschaftssysteme, die mindestens zwei oder drei Abfallbe-handlungssysteme beinhalten, sind deshalb gefragt. 11. Die Ziele der Gesellschaft sind ausschlaggebend und sind die Schlüsselfaktoren für den Entscheidungsprozess. Die Menge der wiederverwertbaren Materialien, die Brauchbarkeit des Komposts, die Interesse an Vergärung, die Möglichkeit einer Verbrennungsanlage, das Verstehen eines nicht-Verbrennungssystems und die Verfügbarkeit von Land für Deponien, die Notwendigkeit für Elektrizität sind einige Schlüsselfaktoren die überlegt werden müs-sen. Integrierte Abfallwirtschaft ist wahrscheinlich die vernünftigste Vorgehensweise. Dies ermöglicht Flexibilität bei Abfallwirtschaftstechniken und ergänzt sie gegenseitig. 12. Öffentliche Verwaltungen können DMT als eine erste Bewertung der geeignetesten Tech-nologie benutzen. Des weiteren gibt DMT dem Verwaltungspersonal Flexibilität in ihrer Wahl bezüglich der Menge an wiederverwertbarem Abfall unter der Anwendung verschie-denen Technologien, welches eine gut konstruiertes und gut integriertes Abfallbehand-lungssystem für die Gesellschaft darstellt. Fazit Das Fazit ist: die Abfallwirtschaft in einem tropischen Schwellenland ist mit bestimmten Her-ausforderungen verbunden, die behandelt werden müssen. Ökonomische, technische und sozi-ale Kriterien müssen in Betracht gezogen werden bei der Wahl geeigneter städtischer Abfall-wirtschaftsysteme. Begrenzte finanzielle Möglichkeiten, Mangel an öffentlichem Bewusstsein und ein schwaches Wirtschaftssystem sind manchmal verantwortlich für die Wahl eines schlechtes Abfallbehandlungssystems, mit kurzsichtigen und über die Jahren teuren Entschei-dungen statt langfristigen und vernünftigeren Entscheidungen. Wetterbedingungen und die Knappheit an Land in Stadtnähe sind besondere Herausforderungen. Das Entscheidungsinstru-mentarium DMT macht die Identifizierung von Schlüsselfragen nötig für die Formulierung eines nachhaltigen Abfallwirtschaftskonzepts und für die Wahl eines technisch-, ökonomisch- und sozial-akzeptierbaren Abfallwirtschaftssystems, das besonders geeignet ist für tropische Klimate. Die Ergebnisse der DMT-Daten-Analyse bietet eine faire Auswertung für ein adäquates integ-riertes Abfallbehandlungssystems. Wenn einmal ein System identifiziert wurde, werden weitere Studien bezüglich Umsetzbarkeit und Anwendbarkeit nötig sein. Jedoch wird die Notwendig-keit, ausführliche Studien am multiplen Szenarien durchzuführen, minimiert, was erhebliche Ersparnisse für die Stadtverwaltung bedeutet. Eine Feasibility-Study und ein Masterplan haben zu folgen, um die standortspezifischen und Finanzierungsfragen zu klären sowie die Auswahl der spezifischen Anlagentechnik zu definieren.
N2  - Abstract Developing and emerging tropical Asian countries have encountered fast urban development due to the migration of farmers seeking a better life in the city. This resulted in a lack of appro-priate infrastructure and inappropriate social services in many cities. Municipal solid waste management is no exception and is in fact often placed at the bottom of the list of priorities for the cities’ appropriate urban management plans since laws and regulations must first be for-mulated and implemented. The problem of unmanaged municipal solid waste certainly leads to air pollution, disease, and to soil and water contamination. These problems in tropical climates are compounded with high temperature, high-level humidity, heavy rainfall and frequent flooding. Stagnant water and leachate from waste quickly become the breeding grounds of in-sects, rodents and bacteria, thus creating a health hazard for workers and local populations. Moreover, water and groundwater contamination may lead to serious environmental degrada-tion with direct impacts on water supplies, and in the fast degradation of agricultural products, the backbone of most tropical Asian countries. Many cities still allow or tolerate dumping of waste in uncontrolled sites, and open burning that disperses particulates that most likely contain dioxins and furans. Even with increasingly scarce land availability within or in proximity of the cities, sanitary landfill is still the most often cho-sen disposal method around Asia because of its lower cost when compared to modern treatment systems. Yet, most of these landfill sites do not have proper lining, daily covering, methane recovery devices, leachate control systems, nor do they have long-term closure and monitoring plans, which implies short and long-term hazards. Some municipalities opted for incineration, which usually entails high operation and maintenance costs because of the need for supple-mental fuel and often-inappropriate running conditions. Although tropical conditions appear to favor certain disposal systems such as composting, appropriate technology needs to be identi-fied in order to reduce operation and maintenance costs while ensuring good quality outputs; compost plants have often been closed because of poor quality products due to the high content of plastic and glass particulates in the finished product. Tropical Asian cities are now required to identify affordable and sustainable solutions for the management of their increasing amount of waste generated daily, while ensuring minimal environmental impact, social acceptance and minimal land use. The purpose of this dissertation was to develop a user-friendly decision-making tool for public administrators and government officials in tropical Asian developing and emerging cities. This tool was developed based on a list of selected decision-making issues necessary in making an informed decision. The decision-making tool is to be used by decision-makers in making a pre-liminary assessment of a most appropriate waste management and treatment system for their municipality. Tropical Asian cities must consider a number of issues when deciding on their waste management plan such as the continuously changing quantum and composition of waste associated with the increasing population and income per capita, the high humidity levels, and the often-limited financial resources. Other determinant factors include legal, political, institu-tional, social and technical issues. Furthermore, administrators must realize the importance of each stage involved in waste management, which includes waste generation, collection, trans-port, waste characteristics, disposal and treatment. To better understand the complexity of the issues involved in tropical Asian municipalities, the city of Bangkok, Thailand’s largest city and capital, was selected as a case study for the management of its 9,000 tonnes of waste gen-erated daily. Numerous interviews, meetings along with the review of documents, reports and site visits offered an inside view of the tropical city’s various decision-making issues towards its waste management plan, and examine specific problems encountered by the city’s decision-makers. The review and analysis of the decision-making issues involved in Bangkok’s waste management plan showed how the decision-making tool can be used in various Asian tropical cities. In conclusion, waste management in an emerging tropical country involves specific challenges that need to be addressed. Economical, technical and social criteria need to be fully understood as to capacitate government officials in the selection of the most appropriate urban waste man-agement system. Limited budgets, lack of public awareness and poor systems’ management often cloud decision-makers in choosing what appears to be the best solution in the short term, but more costly over the years. Weather conditions and scarcity of land in proximity of the city make waste management especially challenging. The decision-making framework offers a tool to decision-makers, as to facilitate the understanding and identification of key issues necessary in the formulation of a sustainable urban waste management plan and in the selection of a tech-nically, economically and socially acceptable integrated MSW management system. A detailed feasibility study and master plan will follow the preliminary study as to define the plant´s specifications, its location and its financing.
T2  - Werkzeuge zur Entscheidungsfindung für die Auswahl angepasster integrierter Abfallwirtschaftssysteme für tropische Städte Asiens, am Beispiel von Bangkok
KW  - Abfall
KW  - Abfallwirtschaftsplan
KW  - Entwicklungsländer
KW  - Klimaschutz
KW  - Computermodul
KW  - Waste
KW  - Waste management concept
KW  - Developing countries
KW  - Computer model
KW  - Environment
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20071213-10034
ER  - 
TY  - CHAP
A1  - Tsutsumi, Kazutoshi
A1  - Hashimoto, Hiromi
T1  - A Development of the Building Kansei Information Retrieval System
N2  - The purpose of this research is to develop the method to retrieve a building name from the impression of the building. First, the images of the building are registered as database by the questionnaire. Next, the images of the objective building are compared with the degree of matching in image databases, and the building with high synthetic matching degree is retrieved. This system could get a good retrieval result. Moreover, image processing was done, and image databases are trained by neural network from the amount of characteristics of the image, and the retrieval system by image processing was examined.
KW  - Mehragentensystem
KW  - Lernendes System
KW  - Informationssystem
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1884
ER  - 
TY  - JOUR
A1  - Zhang, Chao
A1  - Wang, Cuixia
A1  - Lahmer, Tom
A1  - He, Pengfei
A1  - Rabczuk, Timon
T1  - A dynamic XFEM formulation for crack identification
JF  - International Journal of Mechanics and Materials in Design
N2  - A dynamic XFEM formulation for crack identification
KW  - Angewandte Mathematik
KW  - Stochastik
KW  - Strukturmechanik
Y1  - 2016
SP  - 427
EP  - 448
ER  - 
TY  - THES
A1  - Nour, Mohamed
T1  - A Flexible Model for Incorporating Construction Product Data into Building Information Models
N2  - When considering the integration and interoperability between AEC-FM software applications and construction products' data, it is essential to investigate the state-of-the-art and conduct an extensive review in the literature of both Building Information Models and electronic product catalogues. It was found that there are many reasons and key-barriers that hinder the developed solutions from being implemented. Among the reasons that are attributed to the failure of many previous research projects to achieve this integration aim are the proprietary developments of CAD vendors, the fragmented nature of construction product data i.e. commercial and technical data, the prefabrication versus on-site production, marketing strategies and brand-naming, the referencing of a product to the data of its constituents, availability of life-cycle data in a single point in time where it is needed all over the whole life-cycle of the product itself, taxonomy problems, the inability to extract search parameters from the building information model to participate in the conduction of parametric searches. Finally and most important is keeping the product data in the building information model consistent and up-to-date. Hence, it was found that there is a great potential for construction product data to be integrated to building information models by electronic means in a dynamic and extensible manner that prevents the model from getting obsolete. The study has managed to establish a solution concept that links continually updated and extensible life-cycle product data to a software independent building information model (IFC) all over the life span of the product itself. As a result, the solution concept has managed to reach a reliable building information model that is capable of overcoming the majority of the above mentioned barriers. In the meantime, the solution is capable of referencing, retrieving, updating, and merging product data at any point in time. A distributed network application that represents all the involved parties in the construction product value chain is simulated by real software tools to demonstrate the proof of concept of this research work.
N2  - Die vorliegende Dissertation stellt ein flexibles und dynamisches Gebäudeinformationsmodell vor, mit dem die Produktinformationen der Bauteile erfragt und aktualisiert werden können. Dazu werden Beziehungen zwischen den Bauteilen im Gebäudeinformationsmodell und den Produktinformationen der Hersteller und Lieferanten definiert. Die Produktinformationen können über eindeutige Produktnamen und über verallgemeinerte Produktparameter identifiziert werden. Der Stand der Technik bei den digitalen Bauteilkatalogen besteht überwiegend in einer Beschreibung der Produkte in Dokumenten im HTML- oder PDF-Format. Diese Dokumente können mit Hilfe von Schlüsselwörtern durchsucht werden. Hierbei besteht das Problem, dass die Produktinformationen nicht dauerhaft den Objekten im Gebäudeinformationsmodell zuzuordnen sind. Demzufolge kann verfügbare CAD-Software die verwendeten Produkte der Bauteile nicht vollständig beschreiben. Da viele Prozesse aktuelle Informationen der Bauteilprodukte benötigen, ist eine Erweiterung vorhandener Gebäudeinformationsmodelle um diesen Aspekt erforderlich. Obwohl dies Gegenstand zahlreicher proprietärer Entwicklungen ist, ist der Austausch von Daten infolge fehlender Standardisierung nicht ohne Informationsverluste möglich. Diesem Thema widmen sich derzeit unabhängige Forschungsprojekte, in denen neue Taxonomien und Ontologien für die Beschreibung der Semantik von Bauteildaten auf Basis von XML entwickelt werden. Diese Lösungsansätze haben den Nachteil, dass die Produktinformationen der Hersteller und Lieferanten notwendigerweise in einer gemeinsamen Datenbasis gespeichert werden müssen. Die Untersuchung des Lebenszyklus von Bauwerken im Hinblick auf die Wertschöpfungskette und die Beschaffungskette ergab, dass die Informationen sowohl der Bauteile als auch der Produkte über die gesamte Lebensdauer des Bauwerks verfügbar sein müssen. Aus kaufmännischer Sicht besteht das Problem, dass die Produkte eines Herstellers unter verschiedenen Markennamen angeboten und verkauft werden. Untersuchungen haben gezeigt, dass der Markenname ein wesentlicher Faktor einer Marktstrategie ist. Auch die Zwischenhändler spielen hierbei eine wichtige Rolle – selbst dann, wenn die Geschäfte über das Internet abgewickelt werden. Bauteile haben die Besonderheit, dass sie teilweise oder ganz auf der Baustelle hergestellt werden. Dies muss bei der Konzeption eines Informationssystems, das sich mit der Wertschöpfungskette von Bauwerken befasst, beachtet werden. Eine Erkenntnis der vorliegenden Arbeit ist, dass eine parametrisierte Produktsuche nur möglich ist, wenn die Produkte eindeutige Namen und standardisierte Parameter besitzen. Dieser Lösungsansatz könnte die derzeitige Arbeitsweise in der Praxis ändern. Für die prototypische Umsetzung im Rahmen der Dissertation hat sich eine Abstützung auf das verfügbare IFC-Modell als besonders geeignet erwiesen, da dieses Modell nicht-proprietär, fachübergreifend sowie durch Eigenschaften erweiterbar ist. Der Kerngedanke des vorgestellten Lösungskonzepts besteht in der Entwicklung des OIP-Konzepts (Object Information Pack), welches eine dauerhafte und dynamische Datenquelle für Gebäudeinformationsmodelle behandelt. Die OIP ist nicht nur ein eindeutiger Produktname, sondern eine ganze Datenstruktur für Produktinformationen im Bauwesen. Die OIP besteht aus einer dreischichtigen Hierarchie, welche sich sowohl in der Struktur der Datenbasis als auch in der Struktur der Klassen widerspiegelt. Diese Struktur wird über eine Gruppe von Relationen vom OIP-Kern verwaltet. Das Format der OIP-Namen sowie die Verteilung der Daten zwischen den Beteiligten (produktunabhängige technische Daten und produktabhängige Daten der Lieferanten) sind die wesentlichen Neuerungen gegenüber den bekannten Ansätzen mit einer zentralen Datenbasis. Das in dieser Arbeit vorgestellte Lösungskonzept basiert auf einer eingehenden Betrachtung und Analyse der Beschaffungskette von Bauwerken unter Beachtung der Besonderheiten des Bauwesens. Es hat sich herausgestellt, dass das OIP-Konzept allein nicht ausreicht, um eine Brücke zwischen den Daten der Hersteller und Händler auf der einen und dem Kunden auf der anderen Seite zu schlagen. Darüber hinaus wurde eine integrierte Softwarelösung für die Umsetzung des Konzepts benötigt, die zum Zeitpunkt des Entstehens dieser Dissertation nicht verfügbar war. Daher hat der Autor Werkzeuge mit folgender Funktionalität entwickelt: Parsen von STEP-ISO-10303-P21-Dateien Interpretation der geparsten Daten in IFC2x-Java-Klassen Abbildung und Integration von Produktdaten in das IFC-Modell Instanziierung, Löschen und Änderung von Objekten Definition von Suchparametern durch den Anwender Extraktion von Suchparametern aus dem CAD/IFC-Model Durchführen von parametrisierten Suchen Bereitstellung verschiedener Arten der Visualisierung des IFC Modells Export des modifizierten IFC-Modells in Form einer STEP-P21-Datei Mit diesen Werkzeugen konnte das Konzept der Arbeit verifiziert werden. Aufgrund ihres flexiblen Entwurfs können diese Werkzeuge darüber hinaus auch bei anderen Problemstellungen im Zusammenhang mit dem IFC-Modell verwendet werden. Es handelt sich nämlich um einfache Werkzeuge, die eine Integration des IFC-Modells in andere Applikationen ermöglichen. Die Einführung des Konzepts in die Praxis erfordert die Verwaltung durch eine eigene Organisation. Die Rolle dieser OIP-Organisation und das Internetportal der Hersteller wurden ebenfalls innerhalb einer verteilten Applikation simuliert. Zur übersichtlichen Darstellung der Ergebnisse und zum Nachweis der Anwendbarkeit des Konzeptes wurden alle Werkzeuge mit einer graphischen Nutzeroberflächen ausgestattet. Schließlich möchte der Autor betonen, dass eine Übernahme eines solchen „Business Process Re-engeneering“ (BPR) Konzeptes in die industrielle Praxis nicht frei von Barrieren und Problemen ist. Aus der Literatur über Firmenkultur und Psychologie ist bekannt, dass Nutzer oft ablehnend auf die Einführung neuer Systeme reagieren, wenn diese die gewohnte Arbeitsweise in Frage stellen. Hierbei spielt es keine Rolle, ob das resultierende Ergebnis auf lange Sicht zu einer Optimierung und Reduzierung des Aufwands führt. Ein Wechsel der derzeitigen Praxis könnte jedoch erreicht werden, wenn einige innovative Unternehmen ihren Anwendern die Gelegenheit gäben, sich von den Vorteilen der neuen Arbeitsweise zu überzeugen.
KW  - Produktinformation
KW  - Bauteil
KW  - Informationsmodell
KW  - Construction Product data
KW  - IFC
KW  - BIM
KW  - Building Information Model
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20060317-7781
ER  - 
TY  - CHAP
A1  - Freundt, Martin
A1  - Beucke, Karl
T1  - A flexible model for scheduling building processes based on graph theory and fuzzy numbers
N2  - The methods currently used for scheduling building processes have some major advantages as well as disadvantages. The main advantages are the arrangement of the tasks of a project in a clear, easily readable form and the calculation of valuable information like critical paths. The main disadvantage on the other hand is the inflexibility of the model caused by the modeling paradigms. Small changes of the modeled information strongly influence the whole model and lead to the need to change many more details in the plan. In this article an approach is introduced allowing the creation of more flexible schedules. It aims towards a more robust model that lowers the need to change more than a few information while being able to calculate the important propositions of the known models and leading to further valuable conclusions.
KW  - Baubetrieb
KW  - Computerunterstütztes Verfahren
KW  - Scheduling
KW  - Fuzzy-Logik
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1587
ER  - 
TY  - CHAP
A1  - Schapke, Sven-Eric
A1  - Scherer, Raimar J.
T1  - A Four Layer Bayesian Network for Product Model Based Information Mining
N2  - Business and engineering knowledge in AEC/FM is captured mainly implicitly in project and corporate document repositories. Even with the increasing integration of model-based systems with project information spaces, a large percentage of the information exchange will further on rely on isolated and rather poorly structured text documents. In this paper we propose an approach enabling the use of product model data as a primary source of engineering knowledge to support information externalisation from relevant construction documents, to provide for domain-specific information retrieval, and to help in re-organising and re-contextualising documents in accordance to the user’s discipline-specific tasks and information needs. Suggested is a retrieval and mining framework combining methods for analysing text documents, filtering product models and reasoning on Bayesian networks to explicitly represent the content of text repositories in personalisable semantic content networks. We describe the proposed basic network that can be realised on short-term using minimal product model information as well as various extensions towards a full-fledged added value integration of document-based and model-based information.
KW  - Bauwerk
KW  - Datenmanagement
KW  - Produktmodell
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1207
ER  - 
TY  - CHAP
A1  - Brehm, Maik
A1  - Most, Thomas
T1  - A Four-Node Plane EAS-Element for Stochastic Nonlinear Materials
N2  - Iso-parametric finite elements with linear shape functions show in general a too stiff element behavior, called locking. By the investigation of structural parts under bending loading the so-called shear locking appears, because these elements can not reproduce pure bending modes. Many studies dealt with the locking problem and a number of methods to avoid the undesirable effects have been developed. Two well known methods are the >Assumed Natural Strain< (ANS) method and the >Enhanced Assumed Strain< (EAS) method. In this study the EAS method is applied to a four-node plane element with four EAS-parameters. The paper will describe the well-known linear formulation, its extension to nonlinear materials and the modeling of material uncertainties with random fields. For nonlinear material behavior the EAS parameters can not be determined directly. Here the problem is solved by using an internal iteration at the element level, which is much more efficient and stable than the determination via a global iteration. To verify the deterministic element behavior the results of common test examples are presented for linear and nonlinear materials. The modeling of material uncertainties is done by point-discretized random fields. To show the applicability of the element for stochastic finite element calculations Latin Hypercube Sampling was applied to investigate the stochastic hardening behavior of a cantilever beam with nonlinear material. The enhanced linear element can be applied as an alternative to higher-order finite elements where more nodes are necessary. The presented element formulation can be used in a similar manner to improve stochastic linear solid elements.
KW  - Nichtlineare Mechanik
KW  - Finite-Elemente-Methode
KW  - Zufallsvariable
Y1  - 2003
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2825
ER  - 
TY  - THES
A1  - Vogler, Verena
T1  - A framework for artificial coral reef design: Integrating computational modelling and high precision monitoring strategies for artificial coral reefs – an Ecosystem-aware design approach in times of climate change
N2  - Tropical coral reefs, one of the world’s oldest ecosystems which support some of the highest levels of biodiversity on the planet, are currently facing an unprecedented ecological crisis during this massive human-activity-induced period of extinction. Hence, tropical reefs symbolically stand for the destructive effects of human activities on nature [4], [5]. Artificial reefs are excellent examples of how architectural design can be combined with ecosystem regeneration [6], [7], [8]. However, to work at the interface between the artificial and the complex and temporal nature of natural systems presents a challenge, i.a. in respect to the B-rep modelling legacy of computational modelling. 
The presented doctorate investigates strategies on how to apply digital practice to realise what is an essential bulwark to retain reefs in impossibly challenging times. Beyond the main question of integrating computational modelling and high precision monitoring strategies in artificial coral reef design, this doctorate explores techniques, methods, and linking frameworks to support future research and practice in ecology led design contexts.
Considering the many existing approaches for artificial coral reefs design, one finds they often fall short in precisely understanding the relationships between architectural and ecological aspects (e.g. how a surface design and material composition can foster coral larvae settlement, or structural three-dimensionality enhance biodiversity) and lack an integrated underwater (UW) monitoring process. Such a process is necessary in order to gather knowledge about the ecosystem and make it available for design, and to learn whether artificial structures contribute to reef regeneration or rather harm the coral reef ecosystem. 
For the research, empirical experimental methods were applied: Algorithmic coral reef design, high precision UW monitoring, computational modelling and simulation, and validated through parallel real-world physical experimentation – two Artificial Reef Prototypes (ARPs) in Gili Trawangan, Indonesia (2012–today). Multiple discrete methods and sub techniques were developed in seventeen computational experiments and applied in a way in which many are cross valid and integrated in an overall framework that is offered as a significant contribution to the field. Other main contributions include the Ecosystem-aware design approach, Key Performance Indicators (KPIs) for coral reef design, algorithmic design and fabrication of Biorock cathodes, new high precision UW monitoring strategies, long-term real-world constructed experiments, new digital analysis methods and two new front-end web-based tools for reef design and monitoring reefs. The methodological framework is a finding of the research that has many technical components that were tested and combined in this way for the very first time.
In summary, the thesis responds to the urgency and relevance in preserving marine species in tropical reefs during this massive extinction period by offering a differentiated approach towards artificial coral reefs – demonstrating the feasibility of digitally designing such ‘living architecture’ according to multiple context and performance parameters. It also provides an in-depth critical discussion of computational design and architecture in the context of ecosystem regeneration and Planetary Thinking. In that respect, the thesis functions as both theoretical and practical background for computational design, ecology and marine conservation – not only to foster the design of artificial coral reefs technically but also to provide essential criteria and techniques for conceiving them.

Keywords: Artificial coral reefs, computational modelling, high precision underwater monitoring, ecology in design.
N2  - Charakteristisch für das Zeitalter des Klimawandels sind die durch den Menschen verursachte Meeresverschmutzung sowie ein massiver Rückgang der Artenvielfalt in den Weltmeeren. Tropische Korallenriffe sind als eines der ältesten und artenreichsten Ökosysteme der Erde besonders stark gefährdet und stehen somit symbolisch für die zerstörerischen Auswirkungen menschlicher Aktivitäten auf die Natur [4], [5]. Um dem massiven Rückgang der Korallenriffe entgegenzuwirken, wurden von Menschen künstliche Riffsysteme entwickelt [6], [7]. Sie sind Beispiele dafür, wie Architektur und die Regenerierung von Ökosystemen miteinander verbunden werden können [8]. Eine Verknüpfung von einerseits künstlichen und andererseits komplexen, sich verändernden natürlichen Systemen, stellt jedoch eine Herausforderung dar, u.a. in Bezug auf die Computermodellierung (B-Rep Modellierung). 
Zum Erhalt der Korallenriffe werden in der vorliegende Doktorarbeit Strategien aus der digitalen Praxis neuartig auf das Entwerfen von künstlichen Korallenriffen angewendet. Die Hauptfrage befasst sich damit, wie der Entwurfsprozess von künstlichen Korallenriffen unter Einbeziehung von Computermodellierung und hochpräzisen Überwachungsstrategien optimiert werden kann. In diesem Zusammenhang werden Techniken, Methoden sowie ein übergeordnetes Framework erforscht, welche zukünftige Forschung und Praxis in Bezug auf Ökologie-geleitete Entwurfsprozesse fördern soll. 
In Anbetracht der vielen vorhandenen künstlichen Riffsysteme, kann man feststellen, dass die Zusammenhänge zwischen Architektur- und Ökosystem-Anforderungen nicht genau untersucht und dadurch bei der Umsetzung nicht entsprechend berücksichtigt werden. Zum Beispiel wie Oberflächenbeschaffenheit und Materialität eine Ansiedlung von Korallenlarven begünstigt oder wie eine räumlich vielseitige Struktur die Artenvielfalt verbessern kann. Zudem fehlt ein integrierter Unterwasser-Überwachungsprozess, welcher Informationen über das Ökosystem liefert und diese dem Entwurf bereitstellt. Zusätzlich ist eine Unterwasser-Überwachung notwendig, um herauszufinden, ob die künstlichen Riffstrukturen zur Regenerierung beitragen oder dem Ökosystem gänzlich schaden.
In dieser Forschungsarbeit werden empirische und experimentelle Methoden angewendet: Algorithmisches Entwerfen für Korallenriffe, hochpräzise Unterwasser-Überwachung, Computermodellierung und -simulation. Die Forschung wird seit 2012 bis heute durch zwei Riffprototypen (Artificial Reef Prototypes – ARPs) in Gili Trawangan, Indonesien validiert. Zusätzlich wurden weitere separate Methoden und Techniken in insgesamt siebzehn computergestützten Experimenten entwickelt und so angewendet, dass viele kreuzvalidiert und in ein Framework integriert sind, welches dann als bedeutender Beitrag dem Forschungsgebiet zur Verfügung steht. Weitere Hauptbeiträge sind der Ökosystem-bewusste Entwurfsansatz (Ecosystem-aware design approach), Key Performance Indicators (KPIs) für das Gestalten von Korallenriffen, algorithmisches Entwerfen und die Herstellung von Biorock-Kathoden, neue hochpräzise Unterwasser-Überwachungsstrategien, reale Langzeitexperimente, neue digitale Analysemethoden, sowie zwei webbasierte Softwareanwendungen für die Gestaltung und die Überwachung von künstlichen Korallenriffen. Das methodische Framework ist das Hauptergebnis der Forschung, da die vielen technischen Komponenten in dieser Weise zum ersten Mal getestet und kombiniert wurden.
Zusammenfassend reagiert die vorliegende Doktorarbeit sowohl auf die Dringlichkeit als auch auf die Relevanz der Erhaltung von Artenvielfalt in tropischen Korallenriffen in Zeiten eines massiven Aussterbens, indem sie einen differenzierten Entwurfsansatz für künstliche Korallenriffe offeriert. Die Arbeit zeigt auf, dass ein digitales Entwerfen einer solchen „lebendigen Architektur“ unter Berücksichtigung vielfältiger Anforderungen und Leistungsparametern machbar ist. Zusätzlich bietet sie eine ausführliche kritische Diskussion über die Rolle von computergestützten Entwerfen und Architektur im Zusammenhang mit Regenerierung von Ökosystemen und “Planetary Thinking”. In dieser Hinsicht fungiert die Doktorarbeit als theoretischer und praktischer Hintergrund für computergestütztes Entwerfen, Ökologie und Meeresschutz. Eine Verbesserung des Entwerfens von künstlichen Korallenriffen wird nicht nur auf technischer Ebene aufgezeigt, sondern es werden auch die wesentlichen Kriterien und Techniken für deren Umsetzung benannt.

Schlüsselwörter: Künstliche Korallenriffe, Computermodellierung, hochpräzise Unterwasser-Überwachung, Ökologie im Architekturentwurf.
KW  - Korallenriff
KW  - Algorithmus
KW  - Architektur
KW  - Meeresökologie
KW  - Software
KW  - Artificial coral reefs
KW  - Computational modelling
KW  - High precision underwater monitoring
KW  - Ecology in design
KW  - Künstliche Korallenriffe
KW  - Unterwasserarchitektur
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220322-46115
UR  - https://artificialreefdesign.com/
SN  - 978-3-00-074495-2
N1  - Die URL führt zu 3D Modelle von echten Korallenriffen.
ER  - 
TY  - CHAP
A1  - Bédard, Claude
A1  - Mora, Rodrigo
A1  - Rivard, Hugues
T1  - A Framework for Computer-Aided Conceptual Design of Building Structures
N2  - This paper describes a framework for computer-aided conceptual design of building structures that results from building architectural considerations. The central task that is carried out during conceptual design is the synthesis of the structural system. This paper proposes a methodology for the synthesis of structural solutions. Given the nature of architectural constraints, user-model interactivity is devised as the most suitable computer methodology for driving the structural synthesis process. Taking advantage of the hierarchical organization of the structural system, this research proposes a top-down approach for structural synthesis. Through hierarchical refinement, the approach lends itself to the synthesis of global and local structural solutions. The components required for implementing the proposed methodology are briefly described. The main components have been incorporated in a proof-of-concept prototype that is being tested and validated with actual buildings.
KW  - Konzipieren <Technik>
KW  - Bauwerk
KW  - Software Engineering
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1018
ER  - 
TY  - CHAP
A1  - Baitsch, Matthias
A1  - Hartmann, Dietrich
ED  - Gürlebeck, Klaus
ED  - Könke, Carsten
T1  - A FRAMEWORK FOR THE INTERACTIVE VISUALIZATION OF ENGINEERING MODELS
N2  - Interactive visualization based on 3D computer graphics nowadays is an indispensable part of any simulation software used in engineering. Nevertheless, the implementation of such visualization software components is often avoided in research projects because it is a challenging and potentially time consuming task. In this contribution, a novel Java framework for the interactive visualization of engineering models is introduced. It supports the task of implementing engineering visualization software by providing adequate program logic as well as high level classes for the visual representation of entities typical for engineering models. The presented framework is built on top of the open source visualization toolkit VTK. In VTK, a visualization model is established by connecting several filter objects in a so called visualization pipeline. Although designing and implementing a good pipeline layout is demanding, VTK does not support the reuse of pipeline layouts directly. Our framework tailors VTK to engineering applications on two levels. On the first level it adds new – engineering model specific – filter classes to VTK. On the second level, ready made pipeline layouts for certain aspects of engineering models are provided. For instance there is a pipeline class for one-dimensional elements like trusses and beams that is capable of showing the elements along with deformations and member forces. In order to facilitate the implementation of a graphical user interface (GUI) for each pipeline class, there exists a reusable Java Swing GUI component that allows the user to configure the appearance of the visualization model. Because of the flexible structure, the framework can be easily adapted and extended to new problem domains. Currently it is used in (i) an object-oriented p-version finite element code for design optimization, (ii) an agent based monitoring system for dam structures and (iii) the simulation of destruction processes by controlled explosives based on multibody dynamics. Application examples from all three domains illustrates that the approach presented is powerful as well as versatile.
KW  - Architektur <Informatik>
KW  - CAD
KW  - Computerunterstütztes Verfahren
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170327-29194
UR  - http://euklid.bauing.uni-weimar.de/ikm2006/index.php_lang=de&what=papers.html
ER  - 
TY  - JOUR
A1  - Ma, Zhiliang
A1  - Qin, Liang
T1  - A Framework of Management Information System for Construction Projects
N2  - A comprehensive framework of information management system for construction projects in China has been established through extensive literature survey and field investigation. It utilizes the potential information technologies and covers the practical management patterns as well as the major aspects of construction project management. It can be used to guide and evaluate the design of the information management systems for construction projects in order to make the system to be applicable to a wide variety of construction projects and survive the changes in project management.
KW  - Mehragentensystem
KW  - Lernendes System
KW  - Managementinformationssystem
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2126
ER  - 
TY  - INPR
A1  - Wetzstein, Gordon
A1  - Bimber, Oliver
T1  - A Generalized Approach to Radiometric
N2  - We propose a novel method that applies the light transport matrix for performing an image-based radiometric compensation which accounts for all possible types of light modulation. For practical application the matrix is decomposed into clusters of mutually influencing projector and camera pixels. The compensation is modeled as a linear system that can be solved with respect to the projector patterns. Precomputing the inverse light transport in combination with an efficient implementation on the GPU makes interactive compensation rates possible. Our generalized method unifies existing approaches that address individual problems. Based on examples, we show that it is possible to project corrected images onto complex surfaces such as an inter-reflecting statuette, glossy wallpaper, or through highly-refractive glass. Furthermore, we illustrate that a side-effect of our approach is an increase in the overall sharpness of defocused projections.
KW  - Association for Computing Machinery / Special Interest Group on Graphics
KW  - CGI <Computergraphik>
KW  - Maschinelles Sehen
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-7625
ER  - 
TY  - CHAP
A1  - Wiggenbrock, Jens
A1  - Smarsly, Kay
ED  - Gürlebeck, Klaus
ED  - Lahmer, Tom
T1  - A GENERIC FRAMEWORK SUPPORTING DISTRIBUTED COMPUTING IN ENGINEERING APPLICATIONS
T2  - Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar
N2  - Modern distributed engineering applications are based on complex systems consisting of various subsystems that are connected through the Internet. Communication and collaboration within an entire system requires reliable and efficient data exchange between the subsystems. Middleware developed within the web evolution during the past years provides reliable and efficient data exchange for web applications, which can be adopted for solving the data exchange problems in distributed engineering applications. This paper presents a generic approach for reliable and efficient data exchange between engineering devices using existing middleware known from web applications. Different existing middleware is examined with respect to the suitability in engineering applications. In this paper, a suitable middleware is shown and a prototype implementation simulating distributed wind farm control is presented and validated using several performance measurements.
KW  - Angewandte Informatik
KW  - Angewandte Mathematik
KW  - Building Information Modeling
KW  - Computerunterstütztes Verfahren
KW  - Data, information and knowledge modeling in civil engineering; Function theoretic methods and PDE in engineering sciences; Mathematical methods for (robotics and) computer vision; Numerical modeling in engineering; Optimization in engineering applications
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-28260
SN  - 1611-4086
ER  - 
TY  - CHAP
A1  - Häfner, Stefan
A1  - Eckardt, Stefan
A1  - Könke, Carsten
T1  - A geometrical inclusion-matrix model for the finite element analysis of concrete at multiple scales
N2  - This paper introduces a method to generate adequate inclusion-matrix geometries of concrete in two and three dimensions, which are independent of any specific numerical discretization. The article starts with an analysis on shapes of natural aggregates and discusses corresponding mathematical realizations. As a first prototype a two-dimensional generation of a mesoscale model is introduced. Particle size distribution functions are analysed and prepared for simulating an adequate three-dimensional representation of the aggregates within a concrete structure. A sample geometry of a three-dimensional test cube is generated and the finite element analysis of its heterogeneous geometry by a uniform mesh is presented. Concluding, aspects of a multiscale analysis are discussed and possible enhancements are proposed.
KW  - Beton
KW  - Dreidimensionales Modell
KW  - Finite-Elemente-Methode
Y1  - 2003
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-3018
ER  - 
TY  - INPR
A1  - Mosavi, Amir
A1  - Torabi, Mehrnoosh
A1  - Hashemi, Sattar
A1  - Saybani, Mahmoud Reza
A1  - Shamshirband, Shahaboddin
T1  - A Hybrid Clustering and Classification Technique for Forecasting Short-Term Energy Consumption
N2  - Electrical energy distributor companies in Iran have to announce their energy demand at least three 3-day ahead of the market opening. Therefore, an accurate load estimation is highly crucial. This research invoked methodology based on CRISP data mining and used SVM, ANN, and CBA-ANN-SVM (a novel hybrid model of clustering with both widely used ANN and SVM) to predict short-term electrical energy demand of Bandarabbas. In previous studies, researchers introduced few effective parameters with no reasonable error about Bandarabbas power consumption. In this research we tried to recognize all efficient parameters and with the use of CBA-ANN-SVM model, the rate of error has been minimized. After consulting with experts in the field of power consumption and plotting daily power consumption for each week, this research showed that official holidays and weekends have impact on the power consumption. When the weather gets warmer, the consumption of electrical energy increases due to turning on electrical air conditioner. Also, con-sumption patterns in warm and cold months are different. Analyzing power consumption of the same month for different years had shown high similarity in power consumption patterns. Factors with high impact on power consumption were identified and statistical methods were utilized to prove their impacts. Using SVM, ANN and CBA-ANN-SVM, the model was built. Sine the proposed method (CBA-ANN-SVM) has low MAPE 5 1.474 (4 clusters) and MAPE 5 1.297 (3 clusters) in comparison with SVM (MAPE 5 2.015) and ANN (MAPE 5 1.790), this model was selected as the final model. The final model has the benefits from both models and the benefits of clustering. Clustering algorithm with discovering data structure, divides data into several clusters based on similarities and differences between them. Because data inside each cluster are more similar than entire data, modeling in each cluster will present better results. For future research, we suggest using fuzzy methods and genetic algorithm or a hybrid of both to forecast each cluster. It is also possible to use fuzzy methods or genetic algorithms or a hybrid of both without using clustering. It is issued that such models will produce better and more accurate results.
This paper presents a hybrid approach to predict the  electric energy usage of weather-sensitive loads. The presented methodutilizes the clustering paradigm along with ANN and SVMapproaches for accurate short-term prediction of electric energyusage, using weather data. Since the methodology beinginvoked in this research is based on CRISP data mining, datapreparation has received a gr eat deal of attention in thisresear ch. Once data pre-processing was done, the underlyingpattern of electric energy consumption was extracted by themeans of machine learning methods to precisely forecast short-term energy consumption. The proposed approach (CBA-ANN-SVM) was applied to real load data and resulting higher accu-racy comparing to the existing models.
2018 American Institute of Chemical Engineers Environ Prog, 2018 
https://doi.org/10.1002/ep.12934
KW  - Data Mining
KW  - support vector machine (SVM)
KW  - Machine Learning
KW  - forecasting
KW  - Prediction
KW  - Electric Energy Consumption
KW  - clustering
KW  - artificial neural networks (ANN)
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20180907-37550
N1  - This is the pre-peer reviewed version of the following article: https://onlinelibrary.wiley.com/doi/10.1002/ep.12934, which has been published in final form at 
https://doi.org/10.1002/ep.12934. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.
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  - Harirchian, Ehsan
A1  - Kumari, Vandana
A1  - Jadhav, Kirti
A1  - Raj Das, Rohan
A1  - Rasulzade, Shahla
A1  - Lahmer, Tom
T1  - A Machine Learning Framework for Assessing Seismic Hazard Safety of Reinforced Concrete Buildings
JF  - Applied Sciences
N2  - Although averting a seismic disturbance and its physical, social, and economic disruption is practically impossible, using the advancements in computational science and numerical modeling shall equip humanity to predict its severity, understand the outcomes, and equip for post-disaster management. Many buildings exist amidst the developed metropolitan areas, which are senile and still in service. These buildings were also designed before establishing national seismic codes or without the introduction of construction regulations. In that case, risk reduction is significant for developing alternatives and designing suitable models to enhance the existing structure’s performance. Such models will be able to classify risks and casualties related to possible earthquakes through emergency preparation. Thus, it is crucial to recognize structures that are susceptible to earthquake vibrations and need to be prioritized for retrofitting. However, each building’s behavior under seismic actions cannot be studied through performing structural analysis, as it might be unrealistic because of the rigorous computations, long period, and substantial expenditure. Therefore, it calls for a simple, reliable, and accurate process known as Rapid Visual Screening (RVS), which serves as a primary screening platform, including an optimum number of seismic parameters and predetermined performance damage conditions for structures. In this study, the damage classification technique was studied, and the efficacy of the Machine Learning (ML) method in damage prediction via a Support Vector Machine (SVM) model was explored. The ML model is trained and tested separately on damage data from four different earthquakes, namely Ecuador, Haiti, Nepal, and South Korea. Each dataset consists of varying numbers of input data and eight performance modifiers. Based on the study and the results, the ML model using SVM classifies the given input data into the belonging classes and accomplishes the performance on hazard safety evaluation of buildings.
KW  - Erdbeben
KW  - Vulnerability
KW  - Earthquake
KW  - damaged buildings
KW  - earthquake safety assessment
KW  - soft computing techniques
KW  - rapid visual screening
KW  - Machine Learning
KW  - vulnerability assessment
KW  - OA-Publikationsfonds2020
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20201022-42744
UR  - https://www.mdpi.com/2076-3417/10/20/7153
VL  - 2020
IS  - Volume 10, issue 20, article 7153
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Yang, Shih-Wei
A1  - Budarapu, Pattabhi Ramaiah
A1  - Mahapatra, D.R.
A1  - Bordas, Stéphane Pierre Alain
A1  - Zi, Goangseup
A1  - Rabczuk, Timon
T1  - A Meshless Adaptive Multiscale Method for Fracture
JF  - Computational Materials Science
N2  - A Meshless Adaptive Multiscale Method for Fracture
KW  - Angewandte Mathematik
KW  - Strukturmechanik
Y1  - 2015
SP  - 382
EP  - 395
ER  - 
TY  - CHAP
A1  - Rickelt, Christian
A1  - Reese, Stefanie
T1  - A model adaptive and model reduction strategy combining system-theoretical methods and substructuring
N2  - This paper focuses on a new three-level discretisation strategy which enables the transition between continuum/structural (I) and structural/black box modelling (II). The transition (I) is realised by means of a model adaptive concept based on an innovative finite element technology. For transition (II) we apply the truncated balanced realisation method (TBR). The latter represents an established system theoretical model reduction technique which is here combined with a novel substructure technique. The approach provides a modular concept to facilitate the computational analysis of complex structures. The final goal is to apply the strategy to life time estimation.
KW  - Adaptives System
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1516
ER  - 
TY  - JOUR
A1  - Karimimoshaver, Mehrdad
A1  - Hajivaliei, Hatameh
A1  - Shokri, Manouchehr
A1  - Khalesro, Shakila
A1  - Aram, Farshid
A1  - Shamshirband, Shahaboddin
T1  - A Model for Locating Tall Buildings through a Visual Analysis Approach
JF  - Applied Sciences
N2  - Tall buildings have become an integral part of cities despite all their pros and cons. Some current tall buildings have several problems because of their unsuitable location; the problems include increasing density, imposing traffic on urban thoroughfares, blocking view corridors, etc. Some of these buildings have destroyed desirable views of the city. In this research, different criteria have been chosen, such as environment, access, social-economic, land-use, and physical context. These criteria and sub-criteria are prioritized and weighted by the analytic network process (ANP) based on experts’ opinions, using Super Decisions V2.8 software. On the other hand, layers corresponding to sub-criteria were made in ArcGIS 10.3 simultaneously, then via a weighted overlay (map algebra), a locating plan was created. In the next step seven hypothetical tall buildings (20 stories), in the best part of the locating plan, were considered to evaluate how much of theses hypothetical buildings would be visible (fuzzy visibility) from the street and open spaces throughout the city. These processes have been modeled by MATLAB software, and the final fuzzy visibility plan was created by ArcGIS. Fuzzy visibility results can help city managers and planners to choose which location is suitable for a tall building and how much visibility may be appropriate. The proposed model can locate tall buildings based on technical and visual criteria in the future development of the city and it can be widely used in any city as long as the criteria and weights are localized.
KW  - Gebäude
KW  - Energieeffizienz
KW  - Sustainability
KW  - Infrastructures
KW  - OA-Publikationsfonds2020
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210122-43350
UR  - https://www.mdpi.com/2076-3417/10/17/6072
VL  - 2020
IS  - Volume 10, issue 17, article 6072
SP  - 1
EP  - 25
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Most, Thomas
A1  - Bucher, Christian
T1  - A moving least squares weighting function for the element-free Galerkin method which almost fulfills essential boundary conditions
JF  - Structural Engineering and Mechanics
N2  - A moving least squares weighting function for the element-free Galerkin method which almost fulfills essential boundary conditions
KW  - Angewandte Mathematik
KW  - Strukturmechanik
Y1  - 2005
SP  - 315
EP  - 332
ER  - 
TY  - CHAP
A1  - Brackx, Fred
A1  - De Knock, B.
A1  - De Schepper, Hennie
ED  - Gürlebeck, Klaus
ED  - Könke, Carsten
T1  - A MULTI--DIMENSIONAL HILBERT TRANSFORM IN ANISOTROPIC CLIFFORD ANALYSIS
N2  - In earlier research, generalized multidimensional Hilbert transforms have been constructed in m-dimensional Euclidean space, in the framework of Clifford analysis. Clifford analysis, centred around the notion of monogenic functions, may be regarded as a direct and elegant generalization to higher dimension of the theory of the holomorphic functions in the complex plane. The considered Hilbert transforms, usually obtained as a part of the boundary value of an associated Cauchy transform in m+1 dimensions, might be characterized as isotropic, since the metric in the underlying space is the standard Euclidean one. In this paper we adopt the idea of a so-called anisotropic Clifford setting, which leads to the introduction of a metric dependent m-dimensional Hilbert transform, showing, at least formally, the same properties as the isotropic one. The Hilbert transform being an important tool in signal analysis, this metric dependent setting has the advantage of allowing the adjustment of the co-ordinate system to possible preferential directions in the signals to be analyzed. A striking result to be mentioned is that the associated anisotropic (m+1)-dimensional Cauchy transform is no longer uniquely determined, but may stem from a diversity of (m+1)-dimensional "mother" metrics.
KW  - Architektur <Informatik>
KW  - CAD
KW  - Computerunterstütztes Verfahren
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170327-29297
UR  - http://euklid.bauing.uni-weimar.de/ikm2006/index.php_lang=de&what=papers.html
ER  - 
TY  - JOUR
A1  - El-Rayes, Khaled
A1  - Hyari, Khalied
T1  - A Multi-objective Model for Optimizing Construction Planning of Repetitive Infrastructure Projects
N2  - This paper presents the development of a model for optimizing resource utilization in repetitive infrastructure projects. The model provides the capability of simultaneous minimization of both project duration and work interruptions for construction crews. The model provides in a single run, a set of nondominated solutions that represent the tradeoff between these two objectives. The model incorporates a multiobjective genetic algorithm and scheduling algorithm. The model initially generates a randomly selected set of solutions that evolves to a near optimal set of tradeoff solutions in subsequent generations. Each solution represents a unique scheduling solution that is associated with certain project duration and a number of interruption days for utilized construction crews. As such, the model provides project planners with alternative schedules along with their expected duration and resource utilization efficiency.
KW  - Mehragentensystem
KW  - Lernendes System
KW  - Infrastruktur
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2135
ER  - 
TY  - CHAP
A1  - Most, Thomas
A1  - Bucher, Christian
A1  - Macke, M.
ED  - Gürlebeck, Klaus
ED  - Könke, Carsten
T1  - A NATURAL NEIGHBOR BASED MOVING LEAST SQUARES APPROACH WITH INTERPOLATING WEIGHTING FUNCTION
N2  - The Element-free Galerkin Method has become a very popular tool for the simulation of mechanical problems with moving boundaries. The internally applied Moving Least Squares approximation uses in general Gaussian or cubic weighting functions and has compact support. Due to the approximative character of this method the obtained shape functions do not fulfill the interpolation condition, which causes additional numerical effort for the imposition of the essential boundary conditions. The application of a singular weighting function, which leads to singular coefficient matrices at the nodes, can solve this problem, but requires a very careful placement of the integration points. Special procedures for the handling of such singular matrices were proposed in literature, which require additional numerical effort. In this paper a non-singular weighting function is presented, which leads to an exact fulfillment of the interpolation condition. This weighting function leads to regular values of the weights and the coefficient matrices in the whole interpolation domain even at the nodes. Furthermore this function gives much more stable results for varying size of the influence radius and for strongly distorted nodal arrangements than classical weighting function types. Nevertheless, for practical applications the results are similar as these obtained with the regularized weighting type presented by the authors in previous publications. Finally a new concept will be presented, which enables an efficient analysis of systems with strongly varying node density. In this concept the nodal influence domains are adapted depending on the nodal configuration by interpolating the influence radius for each direction from the distances to the natural neighbor nodes. This approach requires a Voronoi diagram of the domain, which is available in this study since Delaunay triangles are used as integration background cells. In the numerical examples it will be shown, that this method leads to a more uniform and reduced number of influencing nodes for systems with varying node density than the classical circular influence domains, which means that the small additional numerical effort for interpolating the influence radius leads to remarkable reduction of the total numerical cost in a linear analysis while obtaining similar results. For nonlinear calculations this advantage would be even more significant.
KW  - Architektur <Informatik>
KW  - CAD
KW  - Computerunterstütztes Verfahren
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170327-29943
UR  - http://euklid.bauing.uni-weimar.de/ikm2006/index.php_lang=de&what=papers.html
ER  - 
TY  - JOUR
A1  - Most, Thomas
T1  - A natural neighbour-based moving least-squares approach for the element-free Galerkin method
JF  - International Journal for Numerical Methods in Engineering
N2  - A natural neighbour-based moving least-squares approach for the element-free Galerkin method
KW  - Angewandte Mathematik
KW  - Strukturmechanik
Y1  - 2007
SP  - 224
EP  - 252
ER  - 
TY  - CHAP
A1  - Montag, U.
T1  - A New Efficient Concept for Elasto-plastic Simulations of Shell Responses
N2  - For the analysis of arbitrary, by Finite Elements discretized shell structures, an efficient numerical simulation strategy with quadratic convergence including geometrically and physically nonlinear effects will be presented. In the beginning, a Finite-Rotation shell theory allowing constant shear deformations across the shell thickness is given in an isoparametric formulation. The assumed-strain concept enables the derivation of a locking-free finite element. The Layered Approach will be applied to ensure a sufficiently precise prediction of the propagation of plastic zones even throughout the shell thickness. The Riks-Wempner-Wessels global iteration scheme will be enhanced by a Line-Search procedure to ensure the tracing of nonlinear deformation paths with rather great load steps even in the post-peak range. The elastic-plastic material model includes isotropic hardening. A new Operator-Split return algorithm ensures considerably exact solution of the initial-value problem even for greater load steps. The combination with consistently linearized constitutive equations ensures quadratic convergence in a close neighbourhood to the exact solution. Finally, several examples will demonstrate accuracy and numerical efficiency of the developed algorithm.
KW  - Schale
KW  - Elastoplastizität
KW  - Finite-Elemente-Methode
Y1  - 1997
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-4364
ER  - 
TY  - JOUR
A1  - Saadatfar, Hamid
A1  - Khosravi, Samiyeh
A1  - Hassannataj Joloudari, Javad
A1  - Mosavi, Amir
A1  - Shamshirband, Shahaboddin
T1  - A New K-Nearest Neighbors Classifier for Big Data Based on Efficient Data Pruning
JF  - Mathematics
N2  - The K-nearest neighbors (KNN) machine learning algorithm is a well-known non-parametric classification method. However, like other traditional data mining methods, applying it on big data comes with computational challenges. Indeed, KNN determines the class of a new sample based on the class of its nearest neighbors; however, identifying the neighbors in a large amount of data imposes a large computational cost so that it is no longer applicable by a single computing machine. One of the proposed techniques to make classification methods applicable on large datasets is pruning. LC-KNN is an improved KNN method which first clusters the data into some smaller partitions using the K-means clustering method; and then applies the KNN for each new sample on the partition which its center is the nearest one. However, because the clusters have different shapes and densities, selection of the appropriate cluster is a challenge. In this paper, an approach has been proposed to improve the pruning phase of the LC-KNN method by taking into account these factors. The proposed approach helps to choose a more appropriate cluster of data for looking for the neighbors, thus, increasing the classification accuracy. The performance of the proposed approach is evaluated on different real datasets. The experimental results show the effectiveness of the proposed approach and its higher classification accuracy and lower time cost in comparison to other recent relevant methods.
KW  - Maschinelles Lernen
KW  - Machine learning
KW  - K-nearest neighbors
KW  - KNN
KW  - classifier
KW  - big data
KW  - clustering
KW  - cluster shape
KW  - cluster density
KW  - classification
KW  - reinforcement learning
KW  - data science
KW  - computation
KW  - artificial intelligence
KW  - OA-Publikationsfonds2020
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200225-40996
UR  - https://www.mdpi.com/2227-7390/8/2/286
VL  - 2020
IS  - volume 8, issue 2, article 286
PB  - MDPI
ER  - 
TY  - JOUR
A1  - Schirmer, Ulrike
A1  - Osburg, Andrea
T1  - A new method for the quantification of adsorbed styrene acrylate copolymer particles on cementitious surfaces: a critical comparative study
JF  - SN Applied Sciences
N2  - The amount of adsorbed styrene acrylate copolymer (SA) particles on cementitious surfaces at the early stage of hydration was quantitatively determined using three different methodological approaches: the depletion method, the visible spectrophotometry (VIS) and the thermo-gravimetry coupled with mass spectrometry (TG–MS). Considering the advantages and disadvantages of each method, including the respectively required sample preparation, the results for four polymer-modified cement pastes, varying in polymer content and cement fineness, were evaluated.

To some extent, significant discrepancies in the adsorption degrees were observed. There is a tendency that significantly lower amounts of adsorbed polymers were identified using TG-MS compared to values determined with the depletion method. Spectrophotometrically generated values were ​​lying in between these extremes. This tendency was found for three of the four cement pastes examined and is originated in sample preparation and methodical limitations.

The main influencing factor is the falsification of the polymer concentration in the liquid phase during centrifugation. Interactions in the interface between sediment and supernatant are the cause. The newly developed method, using TG–MS for the quantification of SA particles, proved to be suitable for dealing with these revealed issues. Here, instead of the fluid phase, the sediment is examined with regard to the polymer content, on which the influence of centrifugation is considerably lower.
KW  - Zement
KW  - Polymere
KW  - polymer adsorption
KW  - cement
KW  - visible spectrophotometry
KW  - depletion method
KW  - mass spectrometry
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210804-44729
UR  - https://link.springer.com/article/10.1007/s42452-020-03825-5
VL  - 2020
IS  - Volume 2, article 2061
SP  - 1
EP  - 11
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Nguyen-Xuan, Hung
A1  - Rabczuk, Timon
A1  - Nguyen-Thanh, Nhon
A1  - Nguyen-Thoi, T.
A1  - Bordas, Stéphane Pierre Alain
T1  - A node-based smoothed finite element method (NS-FEM) for analysis of Reissner-Mindlin plates
JF  - Computational Mechanics
N2  - A node-based smoothed finite element method (NS-FEM) for analysis of Reissner-Mindlin plates
KW  - Angewandte Mathematik
KW  - Strukturmechanik
Y1  - 2010
SP  - 679
EP  - 701
ER  - 
TY  - CHAP
A1  - Oeljeklaus, Michael
T1  - A Non-Modal Structural-Damage-Location Method and its Application
N2  - The paper is about model based parameter identification and damage localization of elastomechanical systems using input and output measurements in the frequency domain. An adaptation of the Projective Input Residual Method to subsystem damage identification is presented. For this purpose the projected residuals were adapted with respect to a given subsystem to be analysed. Based on the gradients of these projected subsystem residuals a damage indicator was introduced which is sensitive to parameter changes and structural damages in this subsystem. Since the computations are done w.r.t. the smaller dimension of a subsystem this indicator shows a computational performance gain compared to the non-subsystem approach. This gain in efficiency makes the indicator applicable in online-monitoring and online-damage-diagnosis where continuous and fast data processing is required. The presented application of the indicator to a gantry robot could illustrate the ability of the indicator to indicate and locate real damage of a complex structure. Since in civil engineering applications the system input is often unknown, further investigations will focus on the output-only case since the generalization of the presented methods to this case will broaden its application spectrum.
KW  - Bruchmechanik
KW  - Modalanalyse
KW  - Parameteridentifikation
Y1  - 2003
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-3397
ER  - 
TY  - THES
A1  - Zhang, Yongzheng
T1  - A Nonlocal Operator Method for Quasi-static and Dynamic Fracture Modeling
N2  - Material failure can be tackled by so-called nonlocal models, which introduce an intrinsic length scale into the formulation and, in the case of material failure, restore the well-posedness of the underlying boundary value problem or initial boundary value problem. Among nonlocal models, peridynamics (PD) has attracted a lot of attention as it allows the natural transition from continuum to discontinue and thus allows modeling of discrete cracks without the need to describe and track the crack topology, which has been a major obstacle in traditional discrete crack approaches. This is achieved by replacing the divergence of the Cauchy stress tensor through an integral over so-called bond forces, which account for the interaction of particles. A quasi-continuum approach is then used to calibrate the material parameters of the bond forces, i.e., equating the PD energy with the energy of a continuum. One major issue for the application of PD to general complex problems is that they are limited to fairly simple material behavior and pure mechanical problems based on explicit time integration. PD has been extended to other applications but losing simultaneously its simplicity and ease in modeling material failure. Furthermore, conventional PD suffers from instability and hourglass modes that require stabilization. It also requires the use of constant horizon sizes, which drastically reduces its computational efficiency. The latter issue was resolved by the so-called dual-horizon peridynamics (DH-PD) formulation and the introduction of the duality of horizons.

Within the nonlocal operator method (NOM), the concept of nonlocality is further extended and can be considered a generalization of DH-PD. Combined with the energy functionals of various physical models, the nonlocal forms based on the dual-support concept can be derived. In addition, the variation of the energy functional allows implicit formulations of the nonlocal theory. While traditional integral equations are formulated in an integral domain, the dual-support approaches are based on dual integral domains. One prominent feature of NOM is its compatibility with variational and weighted residual methods. The NOM yields a direct numerical implementation based on the weighted residual method for many physical problems without the need for shape functions. Only the definition of the energy or boundary value problem is needed to drastically facilitate the implementation. The nonlocal operator plays an equivalent role to the derivatives of the shape functions in meshless methods and finite element methods (FEM). Based on the variational principle, the residual and the tangent stiffness matrix can be obtained with ease by a series of matrix multiplications. In addition, NOM can be used to derive many nonlocal models in strong form.

The principal contributions of this dissertation are the implementation and application of NOM, and also the development of approaches for dealing with fractures within the NOM, mostly for dynamic fractures. The primary coverage and results of the dissertation are as follows:

-The first/higher-order implicit NOM and explicit NOM, including a detailed description of the implementation, are presented. The NOM is based on so-called support, dual-support, nonlocal operators, and an operate energy functional ensuring stability. The nonlocal operator is a generalization of the conventional differential operators. Combining with the method of weighted residuals and variational principles, NOM establishes the residual and tangent stiffness matrix of operate energy functional through some simple matrix without the need of shape functions as in other classical computational methods such as FEM. NOM only requires the definition of the energy drastically simplifying its implementation. For the sake of conciseness, the implementation in this chapter is focused on linear elastic solids only, though the NOM can handle more complex nonlinear problems. An explicit nonlocal operator method for the dynamic analysis of elasticity solid problems is also presented. The explicit NOM avoids the calculation of the tangent stiffness matrix as in the implicit NOM model. The explicit scheme comprises the Verlet-velocity algorithm. The NOM can be very flexible and efficient for solving partial differential equations (PDEs). It's also quite easy for readers to use the NOM and extend it to solve other complicated physical phenomena described by one or a set of PDEs.  Several numerical examples are presented to show the capabilities of this method.

-A nonlocal operator method for the dynamic analysis of (thin) Kirchhoff plates is proposed. The nonlocal Hessian operator is derived from a second-order Taylor series expansion. NOM is higher-order continuous, which is exploited for thin plate analysis that requires $C^1$ continuity. The nonlocal dynamic governing formulation and operator energy functional for Kirchhoff plates are derived from a variational principle. The Verlet-velocity algorithm is used for time discretization. After confirming the accuracy of the nonlocal Hessian operator, several numerical examples are simulated by the nonlocal dynamic Kirchhoff plate formulation.

-A nonlocal fracture modeling is developed and applied to the simulation of quasi-static and dynamic fractures using the NOM. The phase field's nonlocal weak and associated strong forms are derived from a variational principle. The NOM requires only the definition of energy. We present both a nonlocal implicit phase field model and a nonlocal explicit phase field model for fracture; the first approach is better suited for quasi-static fracture problems, while the key application of the latter one is dynamic fracture. To demonstrate the performance of the underlying approach, several benchmark examples for quasi-static and dynamic fracture are solved.
T3  - ISM-Bericht // Institut für Strukturmechanik, Bauhaus-Universität Weimar - 2022,9 
KW  - Variationsprinzip
KW  - Partial Differential Equations
KW  - Taylor Series Expansion
KW  - Peridynamics
KW  - Variational principle
KW  - Phase field method
KW  - Peridynamik
KW  - Phasenfeldmodell
KW  - Partielle Differentialgleichung
KW  - Nichtlokale Operatormethode
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20221026-47321
ER  - 
TY  - CHAP
A1  - Morais, Joao
A1  - Georgiev, Svetlin
A1  - Sprößig, Wolfgang
ED  - Gürlebeck, Klaus
ED  - Lahmer, Tom
ED  - Werner, Frank
T1  - A NOTE ON THE CLIFFORD FOURIER-STIELTJES TRANSFORM
T2  - Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar
N2  - 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.
KW  - Angewandte Informatik
KW  - Angewandte Mathematik
KW  - Computerunterstütztes Verfahren
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-27794
UR  - http://euklid.bauing.uni-weimar.de/ikm2012
SN  - 1611-4086
ER  - 
TY  - CHAP
A1  - Taha, M. M. Reda
A1  - Sherif, Alaa
A1  - Hegger, Josef
T1  - A nouvelle approach for predicting the shear cracking angle in RC and PC beams using artificial neural networks
N2  - The truss model for predicting shear resistance of reinforced concrete beams has usually been criticized because of its underestimation of the concrete shear strength especially for beams with low shear reinforcement. Two challengers are commonly encountered in any truss model and are responsible for its inaccurate shear strength prediction. First: the cracking angle is usually assumed empirically and second the shear contribution of the arching action is usually neglected. This research introduces a nouvelle approach, by using Artificial Neural Network (ANN) for accurately evaluating the shear cracking angle of reinforced and prestressed concrete beams. The model inputs include the beam geometry, concrete strength, the shear reinforcement ratio and the prestressing stress if any. ...
KW  - Neuronales Netz
KW  - Wasserbau
KW  - Scherung
KW  - Rissbildung
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1071
ER  - 
TY  - JOUR
A1  - Jia, Yue
A1  - Zhang, Yongjie
A1  - Rabczuk, Timon
T1  - A Novel Dynamic Multilevel Technique for Image Registration
JF  - Computers and Mathematics with Applications
N2  - A Novel Dynamic Multilevel Technique for Image Registration
KW  - Angewandte Mathematik
KW  - Strukturmechanik
Y1  - 2015
ER  - 
TY  - JOUR
A1  - Nguyen-Tuan, Long
A1  - Lahmer, Tom
A1  - Datcheva, Maria
A1  - Stoimenova, Eugenia
A1  - Schanz, Tom
T1  - A novel parameter identification approach for buffer elements involving complex coupled thermo-hydro-mechanical analyses
JF  - Computers and Geotechnics
N2  - A novel parameter identification approach for buffer elements involving complex coupled thermo-hydro-mechanical analyses
KW  - Angewandte Mathematik
KW  - Stochastik
KW  - Strukturmechanik
Y1  - 2016
SP  - 23
EP  - 32
ER  - 
TY  - JOUR
A1  - Ibanez, Stalin
A1  - Kraus, Matthias
T1  - A Numerical Approach for Plastic Cross Cross-Sectional Analyses of Steel Members
JF  - ce/papers
N2  - Global structural analyses in civil engineering are usually performed considering linear-elastic material behavior. However, for steel structures, a certain degree of plasticization depending on the member classification may be considered. Corresponding plastic analyses taking material nonlinearities into account are effectively realized using numerical methods. Frequently applied finite elements of two and three-dimensional models evaluate the plasticity at defined nodes using a yield surface, i.e. by a yield condition, hardening rule, and flow rule. Corresponding calculations are connected to a large numerical as well as time-consuming effort and they do not rely on the theoretical background of beam theory, to which the regulations of standards mainly correspond. For that reason, methods using beam elements (one-dimensional) combined with cross-sectional analyses are commonly applied for steel members in terms of plastic zones theories. In these approaches, plasticization is in general assessed by means of axial stress only. In this paper, more precise numerical representation of the combined stress states, i.e. axial and shear stresses, is presented and results of the proposed approach are validated and discussed.
KW  - Stahlkonstruktion
KW  - Plastizität
KW  - Strukturanalyse
KW  - Stahlbauteil
KW  - Axialspannung
KW  - Finite-Elemente-Methode
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220112-45622
UR  - https://onlinelibrary.wiley.com/doi/full/10.1002/cepa.1527
VL  - 2021
IS  - Volume 4, issue 2-4
SP  - 2098
EP  - 2106
PB  - Ernst & Sohn, a Wiley brand
CY  - Berlin
ER  - 
TY  - THES
A1  - Mukherjee, Nilangshu
T1  - A numerical comparison of the impact of different climatic conditions in different geographic locations on the construction of an office building
N2  - The aim of my research is to observe the variance of energy efficiency of a typical multi-story office building under the exposure of different climatic conditions. Energy efficiency requirements in building codes or energy standards are among the most important single measures for buildings’ energy efficiency. Therefore, this study can be set up for a better understanding of how energy efficiency of a building changes under the effect of adverse to moderate climatic conditions which possess a mentionable effect on the operation of a building.
This thesis is structured in three balanced and conceptual steps. Following the aim of the project, the virtual building model is to be analyzed under the effect of seven distinct climatic conditions namely work environment of New Delhi, Mumbai, Berlin, Lisbon, Copenhagen, Dubai and Montreal. Firstly, the task is to do a complete literature research based on the scope of similar researches and studying the problems in detail along with the theoritical background all the concepts which are implemented to get the numerical results. This chapter also comprises a detailed study of the climatic conditions of the above-mentioned cities. Different climatic traits like temperature variations, count of heating and cooling degree days, relative humidity, temperature range and comfort zonal charts for the specified cities are studied in detail. This study helps to understand the effect of these adverse to moderate climates on the operation of the building. On the second step, the virtual building model is prepared on a software platform named Revit Structures. This virtual building model is not necessarily a complete building, but it has the relevant functionalities of a real building. We perform the energy analysis and the heating and cooling analysis on this virtual building model to study the operational outcome of the building under different climatic conditions in detail. By the end of these above two tasks, two scenarios are observed. On one hand, we have a literature research and on the other hand we have the numerical results. Therefore, finally we present a comparative scenario based on the energy efficient performances of the building under such variant climatic conditions. This is followed by the prediction of thermal comfort level inside the building and it based on Fanger’s PMV Model. Understanding the literature and the numerical values in detail helps us to predict the index thermal comfort level inside the building.
The conclusion of this master thesis focuses mainly on the scopes of improvement of energy efficiency requirements in energy codes if any, differentiated according to specific locations. The initial aim of my hypothesis which is to study the impacts of climatic variations on the energy efficient performances of a building is fulfilled but as such topics have very deep and broad roots, the scope of further improvements is always predominant.
KW  - Klima
KW  - Energieeffizienz
KW  - Climatic conditions
KW  - Building performance
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170811-32700
ER  - 
TY  - THES
A1  - Hollberg, Alexander
T1  - A parametric method for building design optimization based on Life Cycle Assessment
N2  - The building sector is responsible for a large share of human environmental impacts. Architects and planners are the key players for reducing the environmental impacts of buildings, as they define them to a large extent. Life Cycle Assessment (LCA) allows for the holistic environmental analysis of a building. However, it is currently not employed to improve the environmental performance of buildings during the design process, although the potential for optimization is greatest there. One main reason is the lack of an adequate means of applying LCA in the architectural design process. As such, the main objective of this thesis is to develop a method for environmental building design optimization that is applicable in the design process. The key concept proposed in this thesis is to combine LCA with parametric design, because it proved to have a high potential for design optimization.
The research approach includes the analysis of the characteristics of LCA for buildings and the architectural design stages to identify the research gap, the establishment of a requirement catalogue, the development of a method based on a digital, parametric model, and an evaluation of the method.
An analysis of currently available approaches for LCA of buildings indicates that they are either holistic but very complex or simple but not holistic. Furthermore, none of them provide the opportunity for optimization in the architectural design process, which is the main research gap. The requirements derived from the analysis have been summarized in the form of a catalogue. This catalogue can be used to evaluate both existing approaches and potential methods developed in the future. In this thesis, it served as guideline for the development of the parametric method – Parametric Life Cycle Assessment (PLCA). The unique main feature of PLCA is that embodied and operational environmental impact are calculated together. In combination with the self-contained workflow of the method, this provides the basis for holistic, time-efficient environmental design optimization. The application of PLCA to three examples indicated that all established mandatory requirements are met. In all cases, environmental impact could be significantly reduced. In comparison to conventional approaches, PLCA was shown to be much more time-efficient.
PLCA allows architects to focus on their main task of designing the building, and finally makes LCA practically useful as one of several criteria for design optimization. With PLCA, the building design can be time-efficiently optimized from the beginning of the most influential early design stages, which has not been possible until now. PLCA provides a good starting point for further research. In the future, it could be extended by integrating the social and economic aspects of sustainability.
T3  - bauhaus.ifex research series - 4 
KW  - Bauentwurf
KW  - Architektur
KW  - Bauökologie
KW  - Nachhaltigkeit
KW  - Life Cycle Assessment
KW  - Parametric Design
KW  - Building Information Modelling
KW  - BIM
KW  - Optimization
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20180928-38000
ER  - 
TY  - THES
A1  - Hollberg, Alexander
T1  - A parametric method for building design optimization based on Life Cycle Assessment - Appendix
T2  - A parametric method for building design optimization based on Life Cycle Assessment
N2  - The building sector is responsible for a large share of human environmental impacts, over which architects and planners have a major influence. The main objective of this thesis is to develop a method for environmental building design optimization based on Life Cycle Assessment (LCA) that is applicable as part of the design process. The research approach includes a thorough analysis of LCA for buildings in relation to the architectural design stages and the establishment of a requirement catalogue. The key concept of the novel method called Parametric Life Cycle Assessment(PLCA) is to combine LCA with parametric design. The application of this method to three examples shows that building designs can be optimized time-efficiently and holistically from the beginning of the most influential early design stages, an achievement which has not been possible until now.
KW  - Ökobilanz
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20161101-26884
ER  - 
TY  - JOUR
A1  - Kerfriden, Pierre
A1  - Goury, O.
A1  - Rabczuk, Timon
A1  - Bordas, Stéphane Pierre Alain
T1  - A partitioned model order reduction approach to rationalise computational expenses in nonlinear fracture mechanics
JF  - Computer Methods in Applied Mechanics and Engineering
N2  - A partitioned model order reduction approach to rationalise computational expenses in nonlinear fracture mechanics
KW  - Angewandte Mathematik
KW  - Strukturmechanik
Y1  - 2013
SP  - 169
EP  - 188
ER  - 
TY  - CHAP
A1  - Halfmann, Ansgar
A1  - Rank, Ernst
A1  - Glück, M.
A1  - Breuer, M.
A1  - Durst, F.
T1  - A partitioned solution approach for the fluid-structure interaction of wind and thin-walled structures
N2  - In many engineering applications two or more different interacting systems require the numer-ical solution of so-called multifield problems. In civil engineering the interaction of fluid and structures plays an important role, i.e. for fabric tensile structures of light and flexible materials often used for large roof systems, capacious umbrellas or canopies. Whereas powerful numerical simulation techniques have been established in structural engineering as well as in fluid mechan-ics, only relatively few approaches to simulate the interaction of fluids with civil engineering constructions have been presented. To determine the wind loads on complex structures, it is still state-of-the-art to apply semi-empirical, strongly simplifying methods or to perform expensive ex-periments in wind tunnels. In this paper an approach of a coupled fluid-structure simulation will be presented for membrane and thin shell structures. The interaction is described by the struc-tural deformation as response to wind forces, resulting in a modification of the fluid flow domain. Besides a realistic determination of the wind loads, information on the structural stability can be obtained. The so-called partitioned solution is based on an iterative frame algorithm, integrating different codes for Computational Fluid Dynamics (CFD) and for Computational Structural Dy-namics (CSD) in an explicit or an implicit time-stepping procedure. All data exchange between the two different applications is performed via a neutral geometric model provided by a coupling interface. A conservative interpolation method is used for the interpolation of the nodal loads. The time-dependent motion of the structure requires a dynamic modification of the different grids and a redefinition of the Navier-Stokes equations in an Arbitrary Langrangian Eulerian (ALE) formulation. As an example for the present implementation, results of a coupled fluid-structure simulation for a textile membrane canopy will be presented.
KW  - Tragwerk
KW  - Dünnwandiges Bauelement
KW  - Windlast
KW  - Flüssigkeit-Bauwerk-Wechselwirkung
Y1  - 2000
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5858
ER  -