TY - JOUR A1 - Likhitruangsilp, Veerasak A1 - Ioannou, Photios T1 - Risk-sensitive Markov Decision Process for Underground Construction Planning and Estimating N2 - This paper presents an application of dynamic decision making under uncertainty in planning and estimating underground construction. The application of the proposed methodology is illustrated by its application to an actual tunneling project—The Hanging Lake Tunnel Project in Colorado, USA. To encompass the typical risks in underground construction, tunneling decisions are structured as a risk-sensitive Markov decision process that reflects the decision process faced by a contractor in each tunneling round. This decision process consists of five basic components: (1) decision stages (locations), (2) system states (ground classes and tunneling methods), (3) alternatives (tunneling methods), (4) ground class transition probabilities, and (5) tunneling cost structure. The paper also presents concepts related to risk preference that are necessary to model the contractor’s risk attitude, including the lottery concept, utility theory, and the delta property. The optimality equation is formulated, the model components are defined, and the model is solved by stochastic dynamic programming. The main results are the optimal construction plans and risk-adjusted project costs, both of which reflect the dynamics of subsurface construction, the uncertainty about geologic variability as a function of available information, and the contractor’s risk preference. KW - Mehragentensystem KW - Lernendes System KW - Tunnel KW - Markowschke KW - Kette Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2247 ER - TY - JOUR A1 - Yabuki, Nobuyoshi A1 - Kotani, Jun A1 - Shitani, Tomoaki T1 - A Steel Bridge Design System Architecture using VR-CAD and Web Service-based Multi-Agents N2 - This paper presents a new design environment based on Multi-Agents and Virtual Reality (VR). In this research, a design system with a virtual reality function was developed. The virtual world was realized by using GL4Java, liquid crystal shutter glasses, sensor systems, etc. And the Multi-Agent CAD system with product models, which had been developed before, was integrated with the VR design system. A prototype system was developed for highway steel plate girder bridges, and was applied to a design problem. The application verified the effectiveness of the developed system. KW - Mehragentensystem KW - Lernendes System KW - Stahlbrücke KW - Virtuelle Realität Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2146 ER - TY - JOUR A1 - Wehner, R. A1 - Steinmann, Frank A1 - Hübler, Reinhard T1 - FLEXOB - Entwicklungstool für dynamische, modellbasierte CAD-Systeme N2 - Objektorientierte Modellierungstechniken werden gegenwärtig vor allem Entwicklern von CAD-Systemen angeboten. Sie erzeugen über die Schritte OO-Modellanalyse und OO-Softwaredesign OO-Programme, die mit ihrer Compilation das durch den Softwareingenieur gefundene Modell festschreiben. Generell, aber insbesondere im Bauwerksdesign, ist dieses Vorgehen unbefriedigend, da hier eine Normung von Modellen nicht gelingt, der Entwurfsprozeß vergleichsweise lang ist und eine Kooperation von Ingenieurgewerken mit verschiedenen Modelldomänen die Regel sind. Darüber hinaus weisen die Modelle in frühen Phasen ein hohes Maß an Unschärfe und Abstraktion auf. CAD-Tools, die diese Phasen unterstützen, benötigen deshalb: statt eines genormten Produktmodells ein einheitliches, kognitiv begründetes Modellstrukturierungsparadigma, für das mit der Objektorientierung eine mögliche Ausprägung gegeben ist, ein explizites, verfügbares Domänenmodell zur fortwährenden Interpretation von Bauwerksmodellen, deskriptive Elemente, die die Interpretation von Objekten und Attributen erleichtern, ein Konzept zur Behandlung von Unschärfe und Abstraktion. Hieraus ergeben sich für die Entwicklung von CAD-Systemen folgende Forderungen : Explizite Verfügbarkeit von Klassenobjekten und deren Erzeugung und Veränderung zur Laufzeit, Vererbung auf Klassen- und Instanzniveau, Erweiterte Attributkonzepte (Facetten), Unterstützung der Aggregation als einer wesentlichen Modellstrukturierungsrelation, Verfügbarkeit von OO-Schnittstellen zum Aufbau von CAD-Systemen aus Tools einerseits, sowie zur Trennung von Modellverwaltung und Modellrepräsentation andererseits. Als ein herausragendes Merkmal des Objektorientierten Paradigmas wird die Anwendungsnähe genannt, da Erscheinungen der behandelten Domäne sich analog in Modellen und Programmen wiederfinden (sollen). Unter der Grundannahme, daß dieses Paradigma auch durch den Anwender zur Erstellung seiner Modellwelten verwendet wird, will FLEXOB eine homogene Umgebung schaffen, die die Modellwelt des Softwareingenieurs zu Analysezwecken dem Anwender zur Verfügung stellt und die die Erweiterung dieser Modellwelt auf deskriptivem Niveau ermöglicht. Das Tool FLEXOB und einige wesentliche Implementationsdetails werden im Beitrag vorgestellt. Es handelt sich bei diesem Tools um eine C++ Klassenbibliothek, die entweder als Objektmodul oder als Windows-DLL verwendet werden kann. Aspekte des Nutzungsregimes solch flexibler Modellverwaltungen werden im Beitrag ebenfalls angespochen. KW - CAD KW - Modellierung Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-4571 ER - TY - JOUR A1 - van Treeck, Christoph A1 - Rank, Ernst T1 - Analysis of building structure and topology based on Graph Theory N2 - Individual views on a building product of people involved in the design process imply different models for planning and calculation. In order to interpret these geometrical, topological and semantical data of a building model we identify a structural component graph, a graph of room faces, a room graph and a relational object graph as aids and we explain algorithms to derive these relations. The application of the technique presented is demonstrated by the analysis and discretization of a sample model in the scope of building energy simulation. KW - Produktmodell KW - Simulation KW - Bautechnik KW - Graphentheorie KW - Ingenieurbau Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2308 ER - TY - JOUR A1 - Lizounov, P. P. T1 - Dynamics of solid and deformable Bodies Systems at complex Movements N2 - Analytical models, describing oscillations of systems of interconnected solid and deformable bodies,making a complex movement in fields of inertia forces and gravitation forces, are resulted. Method of numerical investigation of dynamics of the specified systems, based on sharing of parameter prolongation method, Newton-Kantorovich algorithm, Flocke and Liapunov hteories, is developed. On the basis of constructed analytical models and numerical techniques a new, practically important problems of dynamics of systems, consisting of solid bodies, flexible rods, membranes and soft shells, which make a complex movement in fields of forces of inertia and gravity are solved. The received results are used during designing of responsible elements of structures, making a complex movement, which find application in construction and mechanical engineering. KW - Festkörpermechanik KW - Dynamische Belastung KW - Numerisches Verfahren Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5410 ER - TY - JOUR A1 - Weise, Matthias A1 - Katranuschkov, Peter A1 - Scherer, Raimar J. T1 - Generic Services for the Support of Evolving Building Model Data N2 - Many problems related to data integration in AEC can be better tackled by an approach that takes into account the heterogeneity of tasks, models and applications but does not require continuous consistency of the evolving design data, at each data management operation. Such an approach must incorporate adequate services that can facilitate reintegration of concurrently modified data at reasonably selected coordination points. In this paper we present a set of methods which, used in combination, can achieve that goal. After a description of the principal envisaged cooperative work scenario each of these methods is discussed in detail and current observations drawn from their software realisation are given. Whilst the suggested approach is valid for any EXPRESS-based data model, the practical focus of work has been on facilitating IFC-driven integration. KW - Produktmodell KW - Bautechnik KW - Forschungskooperation KW - EXPRESS Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2077 ER - TY - JOUR A1 - Abdalla, Jamal T1 - Elements of an Agent-based Mediative Communication Protocol for Design Objects N2 - Integrated structural engineering system usually consists of large number of design objects that may be distributed across different platforms. These design objects need to communicate data and information among each other. For efficient communication among design objects a common communication protocol need to be defined. This paper presents the elements of a communication protocol that uses a mediator agent to facilitate communication among design objects. This protocol is termed the Mediative Communication Protocol (MCP). The protocol uses certain design communication performatives and the semantics of an Agent Communication language (ACL) mainly the Knowledge and Query Manipulation Language (KQML) to implement its steps. Details of a Mediator Agent, that will facilitate the communication among design objects, is presented. The Unified Modeling Language (UML) is used to present the Meditative protocol and show how the mediator agent can be use to execute the steps of the meditative communication protocol. An example from structural engineering application is presented to demonstrate and validate the protocol. It is concluded that the meditative protocol is a viable protocol to facilitate object-to-object communication and also has potential to facilitate communication among the different project participants at the higher level of integrated structural engineering systems. KW - Mehragentensystem KW - Lernendes System KW - Kommunikationsprotokoll Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2207 ER - TY - JOUR A1 - Gao, Zuoren A1 - Wu, Weiyu A1 - Ren, Aizhu T1 - Physically Based Modeling and Multi-Physical Simulation System for Wood Structure Fire Performance N2 - This research is devoted to promoting the performance-based engineering in wood structure fire. It looks into the characteristic of the material, structural composing and collapse detecting to find out the main factors in the wood structure collapse in fire. The aim of the research is to provide an automatic simulation platform for the complicated circulation. A physically based model for slim member for beams and columns and a frame of multi-physical simulation are provided to implement the system. The physically based model contains material model, structural mechanics model, material mechanics model, as well as geometry model for the compositive simulation. The multi-physical simulation is built on the model and has the capacity to carry out a simulation combining structural, fire (thermal, CFD) and material degradation simulation. The structural and fire simulation rely on two sophisticated software respectively, ANSYS (an FEA software) and FDS (with a core of CFD). Researchers of the paper develop system by themselves to combine the two existing ones. The system has the capability to calculate the wood char to find out the loss of cross-section and to detect the collapse caused in different ways. The paper gives a sample of Chinese traditional house to show how this simulation system works. KW - Produktmodell KW - Simulation KW - Bautechnik KW - Holzbau KW - Brandschutz Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2381 ER - TY - JOUR A1 - Takagi, Kousuke A1 - Tani, Akinori A1 - Kawamura, Hiroshi T1 - Research on Intelligent Fuzzy Optimal Active and Hybrid Control Systems of Building Structures - Verification of Optimization Method on Switching Rules of Control Forces N2 - Recently, many reseraches on active control systems of building structures are preformed based on modern control theory and are installed real buildings. The authors have already proposed intelligent fuzzy optimal active control (IFOAC) systems. IFOAC systems imitate intelligent activities of human brains such as prediction, adaptation, decision-kaking and so on. In IFOAC systems, objective and subjective judgements on the active control can be taken into account. However, IFOAC systems are considered to be suitable for far-field erathquake and control effect becomes small in case of near-field earthqaukes which include a few velosity pules with large amplitudes. To improve control effect in case of near-souece earthquakes, the authors have also proposed hybrid control (HC) systems, in which IFOAC systems and fuzzy control system are combined. In HC systems, the fuzzy control systems are introduced as a reflective fuzzy active control (RFAC) system and imitates spinal reflection of human. In HC systems, active control forces are activated to buildings in accordance with switching rules on active control forces. In this paper, optimizations on fuzzy control rules in RFAC system and switching rules of active control forces in HC system are performed by Parameter-Free Genetic Algorithms (PfGAs). Here, the optimization is performed by using different earthquake inputs. The results of digital simulations show that the HC system can reduce maximal response displacements under restrictions on strokes of the actuator effectively in case of a near-source earthquake and the effectiveness of the proposed HC system is discussed and clarified. KW - Mehragentensystem KW - Lernendes System KW - Fuzzy-Logik KW - Optimierung Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2238 ER - TY - JOUR A1 - Willenbacher, Heiko A1 - Hübler, Reinhard T1 - Intelligent Link-Management for the Support of Integration in Building Life Cycle N2 - The processes in the life cycle of buildings are characterised by highly distinct teamwork. The integration of all the distributed working participants, by providing an environment, which especially supports the communication and collaboration between the actors, is a fundamental step to improve the efficiency of the involved processes and to reduce the total costs. In this article, a link based modelling approach and its “intelligent” link management is introduced (1). This approach realises an integration environment based on a special building model that acts as a decision support system. The link-based modelling is characterised by the definition and specialisation of links between partial models. These intelligent managed links enable a very flexible and task specific data access and exchange between all the different views and partial models of the participants. KW - Mehragentensystem KW - Lernendes System KW - Bauwerk KW - Lebenszyklus Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2223 ER - TY - JOUR A1 - Motawa, Ibrahim A1 - Anumba, Chimay A1 - El-Hamalawi, A. T1 - Development of a Fuzzy System for Change Prediction in Construction Projects N2 - Change management has been the focus of different IT systems. These IT systems were developed to represent design information, record design rationale, facilitate design coordination and changes. They are largely based on managing reactive changes, particularly design changes, in which changes are recorded and then propagated to the relevant project members. However, proactive changes are hardly dealt with in IT systems. Proactive changes require estimating the likelihood of occurrence of a change event as well as estimating the degree of change impacts on project parameters. Changes in construction projects often result from the uncertainty associated with the imprecise and vague knowledge of much project information at the early stages of projects. This is a major outcome of the case studies carried out as part of this research. Therefore, the proposed model considers that incomplete knowledge and certain project characteristics are always behind change causes. For proactive changes, predicting a change event is the main task for modelling. The prediction model should strive to integrate these main elements: 1) project characteristics that lead to change 2) causes of change, 3) the likelihood of change occurrence, and 4) the change consequences. It should also define the dependency relationships between these elements. However, limited data (documented) are only available from previous projects for change cases and many of the above elements can only be expressed in linguistic terms. This means that the model will simulate the uncertainty and subjectivity associated with these sets of elements. Therefore, a fuzzy model is proposed in this research to capture these elements. The model analyses the impact of each set of elements on the other by assigning fuzzy values for these elements that express the uncertainty and subjectivity of their impact. The main aim is to predict change events and evaluate change effects on project parameters. The fuzzy model described above was developed in an IT system for operational purposes and was designed as a Java package of components with their supporting classes, beans, and files. This paper describes the development and the architecture of the proposed IT system to achieve these requirements. The system is intended to help project teams in dealing with change causes and then the change consequences in construction projects. KW - Mehragentensystem KW - Lernendes System KW - Fuzzy-Logik Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2180 ER - TY - JOUR A1 - Foorgber, U. A1 - Müller, Christian T1 - A Planning Process Model for Computer Supported Cooperative Work in Building Construction N2 - Increasing complexity of today's buildings requires a high level of integration in the planning process. Common planning strategies, where individual project partners cooperate mainly to exchange results, are not suitable to jointly develop project goals and objectives. Integrated planning, a more holistic approach to deal with complex problems, is based on a high degree of communication amoung team members and leads to a goal oriented cooperation. Current approaches in the reasearch area of Computer Supported Cooperative Work (CSCW) poorly meet the requirements in planning. A planning process model, based on the principles of integrated planning will be introduced, aimed to provide the background for the implementation of a CSCW-platform. KW - Bauwesen KW - Integrierte Planung KW - Computer Supported Cooperative Work Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-4922 ER - TY - JOUR A1 - Yabuki, Nobuyoshi A1 - Yoshimura, Yutaka T1 - An Evaluation System for Steel Structures of Hydroelectric Power Stations based on Fault Tree Analysis and Performance Maps N2 - This paper presents an evaluation system for steel structures of hydroelectric power stations, including hydraulic gates and penstocks, based on Fault Tree Analyasis (FTA) and performance maps. This system consists of fault tree diagrams of FTA, performance maps, design and analysis systems, and engineerin databases. These four modules are integrated by appropriate hyperlinks so that the user of this system can use it easily and seamlessly. A well developed system was applied to some illustrative example cases, and they showed that the developed methodology and system worked well and the users found the system useful and effective for their maintenance tasks at powerstations. KW - Wissensmanagement KW - Stahlbau KW - Wasserkraftwerk Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2564 ER - TY - JOUR A1 - Kicinger, Rafal A1 - Arciszewski, Tomasz A1 - De Jong, Kenneth T1 - Distributed Evolutionary Design: Island-Model-based Optimization of Steel Skeleton Structures in Tall Buildings N2 - This paper presents results of a study on distributed, or parallel, evolutionary computation in the topological design of steel structural systems in tall buildings. It describes results of extensive experimental research on various parallel evolutionary architectures applied to a complex structural design problem. The experiments were conducted using Inventor 2003, a networkbased evolutionary design support tool developed at George Mason University. First, a general introduction to evolutionary computation is provided with an emphasis on recent developments in parallel evolutionary architectures. Next, a discussion of conceptual design of steel structural systems in tall buildings is presented. Further, Inventor 2003 is briefly introduced as well as its design representation and evolutionary computation characteristics. Next, the results obtained from systematic design experiments conducted with Inventor 2003 are discussed. The objective of these experiments was to qualitatively and quantitatively investigate evolution of steel structural systems in tall buildings during a distributed evolutionary design process as well as to compare efficiency and effectiveness of various parallel evolutionary architectures with the traditional evolutionary design approaches. Two connectivity topologies (ring topology and fully-connected topology) have been investigated for four populations of structural designs evolving in parallel and using various migration strategies. Also, results of the initial sensitivity studies are reported in which two ways of initializing distributed evolutionary design processes were investigated, using either arbitrarily selected designs as initial parents or randomly generated ones. Finally, initial research conclusions are presented. KW - Mehragentensystem KW - Lernendes System KW - Stahlbau KW - Skelettbau KW - Optimierung Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2195 ER - TY - JOUR A1 - Milbradt, Peter A1 - Schierbaum, Jochen A1 - Schwöppe, Axel T1 - Finite Cell-Elements of Higher Order N2 - The method of the finite elements is an adaptable numerical procedure for interpolation as well as for the numerical approximation of solutions of partial differential equations. The basis of these procedure is the formulation of suitable finite elements and element decompositions of the solution space. Classical finite elements are based on triangles or quadrangles in the two-dimensional space and tetrahedron or hexahedron in the threedimensional space. The use of arbitrary-dimensional convex and non-convex polyhedrons as the geometrical basis of finite elements increases the flexibility of generating finite element decompositions substantially and is sometimes the only way to get a clear decomposition... KW - Finite-Elemente-Methode KW - Physikalisches Verfahren Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2524 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 - JOUR A1 - Rüppel, Uwe T1 - Multimediale Gestaltung von Bestandsverwaltungsprozessen im Bauwesen N2 - Die Kosten für die Unterhaltung von Bauwerken über den Lebenszyklus sind im Vergleich zu den Planungs- und Herstellungskosten erheblich größer. Insbesondere setzt eine Reduzierung des Instandhaltungsaufwandes als Teilprozeß der Bestandsverwaltung das rechtzeitige Erkennen von Bauschäden und das vorausschauende Ergreifen von Gegenmaßnahmen voraus. Das planmäßige Vorgehen beim Erkennen von Bauschäden, d.h. die regelmäßige Überwachung baulicher Anlagen, dient nicht nur dem sparsamen Umgang mit vorhandenen Mitteln, sondern verringert auch die Gefahr des plötzlichen Versagens von tragenden Bauteilen. Dadurch werden Gefahren für die Nutzer der Bauwerke frühzeitig abgewendet. Die Notwendigkeit der systematischen Instandhaltung mit modernen Methoden wird auch in den Schlußfolgerungen des dritten Bauschadensberichts des Bundesministeriums für Raumordnung, Bauwesen und Städtebau unterstrichen. Um den Zustand eines Bauteils festzustellen, werden ausreichende Informationen über Struktur, Material, Alter, Belastungen, Umweltbedingungen etc. benötigt. Zur Verarbeitung dieser Fülle von Informationen unterschiedlichen Typs (z.B. technische Dokumente, CAD-Zeichnungen, Photos etc.) bei der Überwachung und Dokumentation baulicher Anlagen ist eine geeignete DV-Unterstützung notwendig. Zur Verwaltung der komplexen Baustrukturinformationen werden objektorientierte Bauwerksmodelle benötigt. Zur bedarfsgerechten Aufbereitung der unterschiedlichen Informationsarten und -qualitäten ist zusätzlich eine multimediale Informationsverarbeitung sowohl intern als auch in der Benutzungsschnittstelle erforderlich. Im Beitrag werden die Grundlagen objektorientierter Methoden zur Bauwerksmodellierung sowie von Multimedia mit den Bereichen Text, Graphik (Vektor- und Pixelgraphik), Audio, Photo und Video einschließlich deren Verknüpfungsmöglichkeiten im Sinne von Hypermedia an Beispielen erläutert. Zusätzlich werden aktuelle Entwicklungstendenzen im Bereich der Telekommunikation mit den Möglichkeiten des Computernetzes INTERNET zur Bestandsverwaltung in verteilten Systemen aufgezeigt. Abschließend werden Anwendungen der objektorientierten und multimedialen Informationsverarbeitung in der täglichen Ingenieurpraxis am Beispiel des DV-Systems BestandManager zur Überwachung und Dokumentation baulicher Anlagen vorgestellt. KW - Bauwerk KW - Langzeitverhalten KW - Bauschaden KW - Instandhaltung KW - Objektmodell Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-4839 ER - TY - JOUR A1 - Kaklauskas, Gintaris A1 - Cervenka, Vladimir A1 - Cervenka, Jan T1 - Deflection Calculation of RC Beams: Finite Element Software versus Design Code Methods N2 - The paper investigates accuracy of deflection predictions made by the finite element package ATENA and design code methods ACI and EC2. Deflections have been calculated for a large number of experimental reinforced concrete beams reported by three investigators. Statistical parameters have been established for each of the technique at different load levels, separately for the beams with small and moderate reinforcement ratio. KW - Finite-Elemente-Methode KW - Physikalisches Verfahren KW - Balken Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2498 ER - TY - JOUR A1 - Minch, M. J. A1 - Trochanowski, A. T1 - The numerical Modelling and Analysis of RC cracked Structures N2 - The purpose of this paper is to review model for finite element techniques for non-linear crack analysis of reinforced concrete beams and slabs. The non-linear behaviour of concrete and steel were described. Some calculations of >self-stress< for concrete and reinforced concrete beam was made. Current computational aspects are discussed. Several remarks for future studies are also given. The numerical model of the concrete and reinforced concrete was described. The paper shows the results of calculations on a reinforced concrete plane stress panel with cracks. The non-linear, numerical model of calculations of reinforced concrete was assumed. Using finite elements method some calculations were made. The results of calculations like displacements, stresses and cracking are shown on diagrams. They were compared with experimental results and other finding. Some conclusions about the described model and results of calculation are shown. KW - Tragwerk KW - Stahlbeton KW - Rissbildung KW - Modellierung Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5278 ER - TY - JOUR A1 - Dudek, Mariusz T1 - Zur Bewertung der Struktur von Verkehrsnetzen N2 - In diese Veröffentlichung werden die Kennziffern dargestellt, die zur Beurteilung der Struktur von Verkehrsnetzen behilflich sein können. Zu diesem Zweck wurde die Graphentheorie angewendet. Eine erste Gruppe von Bewertungen stützt sich auf die Anzahl der Knoten und Bögen des Netzes. Detailliertere Informationen über Engpässe oder Schwachstellen im Verkehrsnetz erhält man durch die Analyse der Kantenzusammenhangs. Die Unabhängigkeit der einzelnen Verkehrsarten , ihre Bewertung und Maßnahmen, sie zu verbessern werden vorgeschlagen und diskutiert. Weiteren Untersuchungen werden angeregt. KW - Verkehrsnetz KW - Kennzahl KW - Bewertung KW - Graphentheorie Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-4634 ER - TY - JOUR A1 - Katranuschkov, Peter A1 - Gehre, Alexander A1 - Scherer, Raimar J. T1 - User Requirements Capture in Distributed Project Environments: A Process-centred Approach N2 - Efforts to define standards for representing AEC/FM data have been fairly successful. However defining a standard reference process model has not met with the same success. Yet almost every conceptual modelling or software development project starts by defining the business processes to be supported and the related requirements to be satisfied. This paper describes a new process-centred methodology for user requirements capture developed in the ICCI project (IST-2001-33022). Its essence is in recognising user requirements and use cases in the context of the real construction process, identifying the actors and roles for each individual activity and associating these activities with information, communication and standardisation requirements on the basis of a formalised specification, named the Process Matrix. In the paper we outline the history of process matrix development, introduce the basic structure of the matrix and show how it can be further extended and refined. We present also a web-based software implementation of the developed approach, describe how it has been used in ICCI and outline further perspectives. KW - Informationstechnik KW - Forschung KW - Europa KW - Bedarfsforschung Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2029 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 - JOUR A1 - Êirinhevsky, V. V. A1 - Dîkhnyak, B. M. A1 - Êirichevsky, R. V. A1 - Êîzub, Y. G. T1 - Determination of the Temperature of Dissipative Warming and Parameters of Fracture in Elastomers with using of Singular Finite Elements N2 - For modeling of singular fields of stresses and deformations in elasters with a crack is offered to use of three-dimesional a special finite element. Weak compessible of elasters is taken into account on the basis of threefold approximation of fields of displacements, deformations and function of volume change. At intensive cyclic loading of the elastomer constructions with a crack it is necessary to take into account warming and large deformations at the crack top. The stress-deformed state elasters with a crack is determined from the decision of a nonlinear problem by a modified method Newton-Kantorovich. Account stress intensity factors for a rectangular plate with a various arrangement of a through crack is executed. Process of development of a surface crack and dissipative warming in prismatic a element of shift is investigated. KW - Elastomer KW - Temperatur KW - Finite-Elemente-Methode Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5471 ER - TY - JOUR A1 - Kang, Shihchung A1 - Miranda, Eduardo T1 - Automated Simulation of the Erection Activities in Virtual Construction N2 - The goal of the research is the development of a computer system to plan, simulate and visualize erection processes in construction. In the research construction cranes are treated as robots with predefined degrees of freedom and crane-specific motion planning techniques are developed to generate time-optimized and collision-free paths for each piece to be erected in the project. Using inverse kinematics and structural dynamics simulation, the computer system then computes the crane motions and velocities necessary to achieve the previously calculated paths. The main benefits of the research are the accurate planning and scheduling of crane operations leading to optimization of crane usage and project schedules, as well as improving overall crane safety in the project. This research is aimed at the development of systems that will allow computer-assisted erection of civil infrastructure and ultimately to achieve fully-automated erection processes using robotic cranes... KW - Produktmodell KW - Simulation KW - Bautechnik KW - Baukonstruktion KW - Virtuelle Realität Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2310 ER - TY - JOUR A1 - Neuberg, Frank A1 - Fank, Ernst A1 - Ekkerlein, Christian T1 - Integrated Life Cycle Simulation and Assessment of Buildings N2 - Buildings require both for construction and, due to their comparatively long life cycle for maintenance, significant raw material and energy resources. So far available knowledge about resource consumption during an entire life cycle of a building is still quite rare, because various criteria affect each other and/or overlay mutually. In this contribution a model based software concept is presented using an integrated approach for life cycle simulation and assessment of buildings. The essential point of the development consists of connecting an IFC compliant product model of a building via the Internet with data bases for the resource and energy requirement of building materials. Furthermore, numerical simulations allow calculating and minimizing the energy consumption, the resource requirement, the waste streams and also the noxious emissions. In the context of this paper we present the first release of software programs for architects and engineers, which help them to evaluate their design decisions objectively in early planning steps. Additionally the usage of the software is demonstrated by a test case study for a real world building. By applying this software in practice a substantial contribution for saving energy and natural resources can be provided in the sense of sustainable and ecological building design. KW - Produktmodell KW - Simulation KW - Bautechnik KW - Lebenszyklus Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2351 ER - TY - JOUR A1 - Semenov, Vitaly A1 - Alekseeva, Elena A1 - Tarlapan, Oleg T1 - Virtual Construction using Map-based Approach N2 - The paper presents a general map-based approach to prototyping of products in virtual reality environments. Virtual prototyping of products is considered as a consistent simulation and visualization process mapping the source product model into its target visual representations. The approach enables to interrelate formally the product and visual information models with each other by defining mapping rules, to specify a prototyping scenario as a composition of map instances, and then to explore particular product models in virtual reality environments by interpreting the composed scenario. Having been realized, the proposed approach provides for the strongly formalized method and the common software framework to build virtual prototyping applications. As a result, the applications gain in expressiveness, reusability and reliability, as well as take on additional runtime flexibility... KW - Produktmodell KW - Simulation KW - Bautechnik KW - Virtuelle Realität KW - Bauwerk Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2447 ER - TY - JOUR A1 - Kiviniemi, Arto A1 - Fischer, Martin T1 - Requirements Management Interface to Building Product Models N2 - In current AEC practice client requirements are typically recorded in a building program, which, depending on the building type, covers various aspects from the overall goals, activities and spatial needs to very detailed material and condition requirements. This documentation is used as the starting point of the design process, but as the design progresses, it is usually left aside and changes are made incrementally based on the previous design solution. These incremental small changes can lead to a solution that may no longer meet the original requirements. In addition, design is by nature an iterative process and the proposed solutions often also cause evolution in the client requirements. However, the requirements documentation is usually not updated accordingly. Finding the latest updates and evolution of the requirements from the documentation is very difficult, if not impossible. This process can lead to an end result, which is significantly different from the documented requirements. Some important requirements may not be satisfied, and even if the design process was based on agreed-upon changes in the scope and requirements, differences in the requirements documents and in the completed building can lead to well-justified doubts about the quality of the design and construction process... KW - Produktmodell KW - Simulation KW - Bautechnik KW - Bauwerk KW - Modellierung Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2427 ER - TY - JOUR A1 - Kang, Shihchung A1 - Miranda, Eduardo T1 - Physics Based Model for Simulating the Dynamics of Tower Cranes N2 - The goal of the research is to increase the understanding of dynamic behaviors during the crane operation, and develops computer-aided methods to improve the training of crane operators. There are approximately 125,000 cranes in operation today in the construction industry, responsible for major portion of erection activities. Unfortunately, many accidents occur every year in the U.S. and other countries related to the operation of cranes in construction sites. For example on November 28, 1989 a tower crane collapse during the construction of a building in San Francisco killing four construction workers, one civilian and injuring 28. According to the statistics from Occupational Safety Health Administration (OSHA), there were 137 crane-related fatalities from 1992 to 2001 in the US. A well-known internet website that keeps track of crane-related accidents (craneaccidents.com), reports 516 accidents and 277 fatalities from 2000 to 2002. These statistics show that even though many measures have been taken to decrease the number of crane-related accidents (Braam, 2002), the number of crane related accidents is still very large. It is important to recognize that each construction related fatality is not only a great human loss but also increases the costs of insurance, lawsuits, and the construction budget due to delay of a project (Paulson 1992)... KW - Produktmodell KW - Simulation KW - Bautechnik KW - Turmdrehkran KW - Dynamische Belastung Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2409 ER - TY - JOUR A1 - Holtzhauer, Eric A1 - Saal, Helmut T1 - Product modelling in the steel construction domain N2 - The complexity of the relationships between the actors of a building project requires high efficiency in communication. Among other things, data sharing is crucial. The exchange of data is made possible by interfaces between expert programs, which rely on product models. The latter are neutral standards with formal definitions of building objects and their attributes. This paper deals with the state of the art and the research activities concerning product models in the steel construction domain and the advantages provided by this technology for the sector. KW - Produktmodell KW - Simulation KW - Bautechnik KW - Stahlbau Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2415 ER - TY - JOUR A1 - Rose, Martin T1 - Modeling of Freeway Traffic N2 - An integrated modeling of freeway traffic is developed, whose implementation in an uniform computer –aided simulation model facilitate comparative evaluation and systematic coupling of several traffic simulations, traffic controls, traffic measurements and traffic scenarios. The integrated modeling of freeway traffic is a basic mapping of freeway networks, control methods, measurements and different simulations of traffic flow... KW - Verkehrsplanung KW - Simulation KW - Autobahn Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2639 ER - TY - JOUR A1 - Shih, Naai-Jung A1 - Lee, Wen-Pang T1 - Particle Simulation and Evaluation of Personal Exposure to Contaminant Sources in an Elevation Space N2 - An elevator, which figures a small volume, is normally used by everyone for a short period of time and equipped with simple ventilation system..Any contaminant released within it may cause serious problem. This research adapt a fire and smoke simulation software (FDS) into non-fire indoor airflow scario. Differently from previous research, particles are chosen as a risk evalution unit. A personal and multi-personal exposure model is proposed. The model takes the influence of the human thermal boundary, coughing, inhalation, exhalation, standing position, and the fan factor into account. The model is easy-to-use and suitable for the design of elevator system in practice. KW - Produktmodell KW - Simulation KW - Bautechnik KW - Luft KW - Schadstoffkonzentration Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2376 ER - TY - JOUR A1 - Volkova, Viktorija T1 - The analysis of dynamic behaviour of pre-stressed systems under polyharmonic excitations N2 - Pre-stressed structural elements are widely used in large-span structures. As a rule, they have higher stiffness characteristics. Pre-stressed rods can be applied as girders of different purpose, and as their separate parts, e.g. rods of trusses and frames. Among numerous ways of prestressing the compression of girders, trusses, and frames by tightenings from high-strength materials is under common application. KW - Verkehrsplanung KW - Simulation KW - Baukonstruktion KW - Dynamische Belastung KW - Tragwerk / Vorspannung KW - Vorgespannte Konstruktion Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2656 ER - TY - JOUR A1 - Cerovsek, Tomo A1 - Turk, Ziga T1 - Working Together: ICT Infrastructures to Support Collaboration N2 - The paper summarizes a part of research carried out in ICCI project and provides a current review of ICT infrastructures supporting collaboration. It covers taxonomies, protocols, standards, components, typical subsystems as well as future trends and recommendation for two most important technologies with applications in AEC: (1) EIP (Enterprise information portal) – a single gateway to a company's information, knowledge base, and applications for all actors; (2) RTC (Real-Time Communication and Collaboration technologies) that provide means for asynchronous communication between geographically dislocated people using ICT. Proposed future developments are: orientation towards web services - with building information models, business intelligence, personalization, AEC information retrieval, p2p workspaces and grids. KW - Informationstechnik KW - Forschung KW - Europa KW - Teamwork Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2055 ER - TY - JOUR A1 - Makanae, Koji T1 - Highway Sequence Editor based on the Length-based Highway Product Model N2 - The highway product model based on the length information of the centerline, and the application system is developed. This paper shows the schema and the modeling process of the product model, which includes geometric elements such as an alignment, lanes, sidewalks, shoulders and sprits, and accessories such as guard fences, plantings and signs. Furthermore, The Highway Sequence Editor (HSE) is developed as an application system to verify the model. KW - Produktmodell KW - Simulation KW - Bautechnik KW - Straßenbau Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2347 ER - TY - JOUR A1 - Rebolj, D. T1 - A Product Model of a Road N2 - Many errors and delays frequently appear when data is exchanged between particular tasks in the lifecycle of the road. Inter-task connections are therefore of great importance for the quality of the final product. The article describes a product model of a road wich is the kernel of an integrated information system intended to support all important stages of the road lifecycle: design, evaluation (through different analysis procedures), construction, and maintainance. Since particular tasks are often executed at different places and in different companies, the interconnections are supported by a special metafile which contains all specific data of the product model. The concept of the integrated system is object and component oriented. Additionally, existing conventional program packages are included to support some common tasks (methods). A conventional relational database system as well as an open spatial database system with the relevant GIS functionality are included to support the data structures of the model. KW - Straße KW - Modellierung Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-4584 ER - TY - JOUR A1 - Berkowski, P. A1 - Boron, Jacek T1 - An Algorithm of compromise structural Optimisation of Bar Structures N2 - Authors' own research in applied unicriterial and multicriterial optimisation of bar structures, and also an analysis of accessible bibliography on structural synthesis allows to present herein an attempt to define a general algorithm for proceeding in formulation of a structural optimisation problem. A practical aspect of such an algorithm consists, in author's opinion, in enabling a designer a correct creation of a mathematical model of synthesis problems, independently of known mathematical methods employed to looking for an unconditional extremum of function of several variables. A proposed algorithm is not a ready-for-use tool for solving all the optimisation problems, but it constitutes an easy-to-expand theoretical basis. This basis should allow a designer to create a proper set of compromises on the way to construct a mathematical model of a specific optimisation problem. The algorithm, presented in the paper, is constructed as a sequence of the one-after-another problem questions, on which the designer answers: yes or no, and a set of selections from the knowledge base consisting of the elements of an optimisation problem components. The order of making questions adopted by the authors in the algorithm is subjective, however it is supported by their experience, both in applied optimisation and in designing of structures like trusses or frames. KW - Stabwerk KW - Optimierung Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5264 ER - TY - JOUR A1 - Kazakevitch, M. I. A1 - Volkova, Viktorija T1 - The exact Solution of the free pre-stressed Bar-Oscillations N2 - In this paper the results of the investigations of the free oscillations of the pre-stressed flexible structure elements are presented . Two cases of the central preliminary stress are investigated : without intermediate fastening of the tie to the flexible element and with the intermediate fastening in the middle of the element length. The given physical model can be applied to the flexible sloping shells and arches, membranes, large space antenna fields (besides flexible elements). The peculiarity of these systems is the possibility of the non-adjacent equilibrium form existence at the definite relations of the physical parameters . The transition from one stable equilibrium form to another, non-adjacent form, may be treated as jump. In this case they are called systems with buckling or the systems with two potential «gaps». These systems commenced the new section of the mathematical physics - the theory of chaos and strange attractors. The analysis of the solutions confirms the received for the first time by the author and given in effect of the oscillation period doubling of the system during the transition from the «small» oscillations relatively center to the >large< relatively all three equilibrium conditions. The character of the frequency (period) dependence on the free oscillation amplitudes of the non-linear system also confirms the received earlier result of the duality of the system behaviour : >small< oscillations possess the qualities of soft system; >large< oscillations possess the qualities of rigid system. The >small< oscillation natural frequency changing, depending on the oscillation amplitudes, is in the internal . Here the frequency takes zero value at the amplitude values Aa and Ad (or Aa and Ae ); the frequency takes maximum value at the amplitude value near point b .The >large< oscillation natural frequency changes in the interval . Here is also observed . The influence of the tie intermediate fastening doesn't introduce qualitative changes in the behaviour of the investigated system. It only increases ( four times ) the critical value of the preliminary tension force KW - Bauteil KW - Vorspannung KW - Freie Schwingung Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5356 ER - TY - JOUR A1 - Misztal, S. A1 - Misztal, G. T1 - Anwendung von Delta-Dirac-Funktion und Heviside-Funktion zur Berechnung der inneren Kräfte und Verschiebungen in gebogenen Balken N2 - Die d - Dirac - Funktion d(x-xi) und Heviside - Funktion wurden vor allem zur Beschreibung diskontinuierlicher Belastungsfunktionen von gebogenen Balken angewendet. Im Referat werden die mathematischen Operationen auf den erwähnten Funktionen dargestellt. Darüber hinaus wird die Möglichkeit eindeutiger Aufschreibung von belibigen Belestungsfunktionen vorgeschlagen, die fast alle Fälle der in der Ingenieurpraxis auftretenden Belastungen umfassen. Die vorgeschlagenen Lösungen geben die Möglichkeit leichter Aufschreibung im Form eines Algorithmus, das die Ausnutzung von Komputertechnik in statischen Berechnungen ermöglicht. Am Ende des Referates werden die Zahlebeispiele dargestellt, die die Möglichkeiten praktischer Anwendungen der besprochenen Funktionen darstellen. KW - Balken KW - Belastung KW - Mathematisches Modell KW - Computerunterstütztes Verfahren Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5308 ER - TY - JOUR A1 - Firmenich, Berthold T1 - Product Models in Network Based Co-operation in Structural Engineering N2 - The Priority Programme ‘Network Based Co-operation in Structural Engineering’ of the ‘German Research Foundation’ (DFG) has been established in the year 2000. This paper describes and discusses the main research directions and first results of the workgroup ‘Distributed Product Models’. The five projects of the workgroup have developed completely different solutions for specific application domains. Each solution concept deals with a consistent product modeling and knowledge processing in a distributed environment in the planning process. The individual solution approaches of the projects are described and the underlying basic assumptions are discussed. A unified system architecture is described for all projects of the workgroup. Two different approaches (object-oriented and graph-based models) have been introduced for product and knowledge modeling. The common structure of these models will be explained to fully understand the differences of these modeling approaches. Finally the concepts for co-operative work and conflict management in a distributed environment are described: The solution approaches will be distinguished by classifying the supported co-operation according to time. A final scientific summary describes the state-of-the-art in network based co-operation in structural engineering: The role of research directions like knowledge modeling, standard product modeling and versioning in the distributed planning process will be explained. KW - Produktmodell KW - Bautechnik KW - Forschungskooperation Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2119 ER - TY - JOUR A1 - Huhn, Michael T1 - Abstract and Concrete Scenarios in Concurrent Engineering N2 - An architecture of a distributed planning system for the building industry has been developed. The emphasis is on highly collaborative environments in steelwork, timber construction etc. where designers concurrently handle 3D models. The overall system connects local design systems by the so-called Design Framework DFW. This framework consists of the definition of distributed components and protocols which make the collaborative design work. The process of collaborative design has been formalized on an abstract level. This paper describes how this has been done. A sample is given to illustrate the mapping of concrete scenarios of the ‘real design world’ to an abstract scenario level. This work is funded by the Deutsche Forschungsgemeinschaft DFG as part of the project SPP1103 (Meißner et al. 2003). KW - Produktmodell KW - Bautechnik KW - Forschungskooperation KW - Framework Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2068 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 - JOUR A1 - Schnellenbach-Held, Martina A1 - Hartmann, Markus T1 - Knowledge Based Systems in Distributed Desgin Environments N2 - Today’s building industry not only demands more and more reduced construction time on building site, but also an advanced and mostly construction attendant design phase. Even though there is software available to support design processes in distributed environments, most applications only support simple document based exchange of information. In this paper a knowledge based system is presented to support cooperative, comprehensive design processes in distributed environments. The presented research project is financially supported by the German Research Community (DFG – Deutsche Forschungsgemeinschaft). KW - Produktmodell KW - Bautechnik KW - Forschungskooperation KW - Wissensmanagement Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2106 ER - TY - JOUR A1 - Strukelj, A. T1 - Some Problems in Obtaining the Green's Function of the Layered Soil N2 - The frame of this paper is the development of methods and procedures for the description of the motion of an arbitrary shaped foundation. Since the infinite half-space cannot be properly described by a model of finite dimensions without violating the radiation condition, the basic problems are infinite dimensions of the half-space as well as its non-homogeneous nature. Consequently, an approach has been investigated to solve this problem indirectly by developing Green's function in which the non-homogeneity and the infiniteness of the half-space has been included. When the Green's function is known, the next step will be the evaluation of contact stresses acting between the foundation and the surface of the half-space through an integral equation. The equation should be solved in the area of the foundation using Green's function as the kernel. The derivation of three-dimensional Green's function for the homogeneous half-space (Kobayashi and Sasaki 1991) has been made using the potential method. Partial differential equations occurring in the problem have been made ordinary ones through the Hankel integral transform. The general idea for obtaining the three-dimensional Green's function for the layered half-space is similar. But in that case some additional phenomena may occur. One of them is the possibility of the appearance of Stonely surface waves propagating along the contact surfaces of layers. Their contribution to the final result is in most cases important enough that they should not be neglected. The main advantage of results presented in comparing to other obtained with numerical methods is their accuracy especially in the case of thin layers because all essential steps of Green's function evaluation except of the contour integration along the branch cut have been made analytically. On the other hand the disadvantage of this method is that the mathematical effort for obtaining the Green's function is increasing drastically with the increase of the number of layers. Future work will therefore be directed in simplifying of the above described process KW - Bodenmechanik KW - Geschichtetes Medium KW - Green-Funktion Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5388 ER - TY - JOUR A1 - Fink, Thomas T1 - Structural analysis, design and detailing using standard CAD software and standard building information model N2 - This paper describes the concept of a german commercial software package developed for the needs of structural engineers. Using a standard CAD software as user interface for all geometrical data and to save all important input data, there is a natural link to upcoming building information models. KW - Bauindustrie KW - CAD KW - Bauwerk KW - Modellierung Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2702 ER - TY - JOUR A1 - Kaplinski, O. T1 - Phenomenon of inhertia in the Production Systems reliability Analysis N2 - The paper analyses the influence of the effect of inertia on the reliability of production systems. Systems inertia represents the phenomenon of continuing work for some time after the breakdown of one of the former phases. In our considerations, inertia is treated as the time elapsed from the onset of breakdown till the system's inability to work. A special method had to be devised to investigate the effect of inertia in order to evaluate the reliability of production systems and to attempt algorithmization to control the reliability of production system by means of inertia or reserving. The method of reliability analysis is presented only in an inform aspect. The possibilities of increasing reliability of production systems are listed. A comparison of the redundancy method and inertia method is presented. The results of this comparison and simulated investigations of influence of inertia on reliability of system are essential scope of the paper. Selected conclusions are as follows: when inertia approaches the last phase in the system, its influence on the shape of the distribution of the system's ability increases; an increase in inertia causes an increase in the availability of the system which approaches a certain border value; dependence of the average of a system's disability on inertia has a saddle-like character whereas dependence of the number of breakdowns (stoppages) in the system has the nature of an S-curve. KW - Zuverlässigkeitstheorie KW - Trägheit Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5320 ER - TY - JOUR A1 - Ganev, T. A1 - Marinov, M. T1 - Towards Optimal Designing of thin elastic Plates with a specific free Oscillations Frequency N2 - Thin elastic plates are the basic constructional elements and are very often subjected to dynamic effects especially in the machine-building structures. Their saving design of resonance conditions of operation is an extremely complicated task which cannot be solved analytically. In the present report an efficient and sufficiently general method for optimal design of thin plates is worked out on the basis of energy resonance method of Wilder, the method of the finite elements for dynamic research and the methods of parameter optimization. By means of these methods various limitations and requirements put by the designer to the plates can be taken into account. A programme module for numerical investigation of the weight variation of the plate depending on the taken variable of the designed thickness at different supporting conditions is developed. The reasons for the considerable quantity and quality difference between the obtained optimal designs are also analysed. KW - Platte KW - Optimierung KW - Freie Schwingung KW - Finite-Elemente-Methode Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5375 ER - TY - JOUR A1 - Skrinar, Matjaz T1 - Computation of Stresses and Settlements under an arbitrary Point in Homogenous, elastic, isotropic Half-Space, under the Load described by a uniform Load over a general quadrilateral N2 - The problem of the computation of stresses and settlements in the half-space under various types of loads is often presented in geotechnical engineering. In 1885 Boussinesq advanced theoretical expressions to determine stresses at a point within an ideal mass. His equation considers a point load on the surface of a semi-infinite, homogeneous, isotropic, weightless, elastic half-space. Newmark in 1942 performed the integration of Boussinesq's equations for the vertical stress under a corner of a rectangular area loaded with a uniform load. The problem of the determination of vertical stresses under a rectangular shaped footing has been satisfactorily solved with renewal integration of the Boussinesq's equation over the arbitrary rectangle on surface of the half-space, with a non-uniform load represented with piecewise linear interpolation functions. The problem of the determination of stresses in the case when the footing shape is an arbitrary quadrilateral however remains unsolved. The paper discusses an approach to the computation of vertical stresses and settlements in an arbitrary point of the half-space, loaded with a uniform load, which shape in the ground plan can be a general four noded form with straight edges. Since the form is transformed into a biunit square and all integrations are performed over this area, all solutions are valid also for an arbitrary triangle by the implementation of the degeneration rule. KW - Halbraum KW - Isotropie KW - Spannung KW - Setzung Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5338 ER - TY - JOUR A1 - Aziz, Zeeshan A1 - Anumba, Chimay A1 - Miles, John T1 - Towards a Semantic Grid Computing Platform for Disaster Management in Built Environment N2 - Current disaster management procedures rely primarily on heuristics which result in their strategies being very cautious and sub-optimum in terms of saving life, minimising damage and returning the building to its normal function. Also effective disaster management demands decentralized, dynamic, flexible, short term and across domain resource sharing, which is not well supported by existing distributing computing infrastructres. The paper proposes a conceptual framework for emergency management in the built environment, using Semantic Grid as an integrating platform for different technologies. The framework supports a distributed network of specialists in built environment, including structural engineers, building technologists, decision analysts etc. It brings together the necessary technology threads, including the Semantic Web (to provide a framework for shared definitions of terms, resources and relationships), Web Services (to provide dynamic discovery and integration) and Grid Computing (for enhanced computational power, high speed access, collaboration and security control) to support rapid formation of virtual teams for disaster management. The proposed framework also make an extensive use of modelling and simulation (both numerical and using visualisations), data mining (to find resources in legacy data sets) and visualisation. It also include a variety of hardware instruments with access to real time data. Furthermore the whole framework is centred on collaborative working by the virtual team. Although focus of this paper is on disaster management, many aspects of the discussed Grid and Visualisation technologies will be useful for any other forms of collaboration. Conclusions are drawn about the possible future impact on the built environment. KW - Mehragentensystem KW - Lernendes System KW - Katastrophenmanagement KW - Software Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2084 ER - TY - JOUR A1 - Romberg, Richard A1 - Niggl, Andreas A1 - van Treeck, Christoph T1 - Structural Analysis based on the Product Model Standard IFC N2 - In this paper we present a computer aided method supporting co-operation between different project partners, such as architects and engineers, on the basis of strictly three-dimensional models. The center of our software architecture is a product model, described by the Industry Foundation Classes (IFC) of the International Alliance for Interoperability (IAI). From this a geometrical model is extracted and automatically transferred to a computational model serving as a basis for various simulation tasks. In this paper the focus is set on the advantage of the fully three-dimensional structural analysis performed by p-version of the finite element analysis. Other simulation methods are discussed in a separate contribution of this Volume (Treeck 2004). The validity of this approach will be shown in a complex example. KW - Produktmodell KW - Simulation KW - Bautechnik KW - Statik KW - Standard Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2433 ER - TY - JOUR A1 - Kaiser, Wolfgang T1 - Die unbegrenzten Einsatzmöglichkeiten von 3D-Modellierern N2 - Der Funktionsumfang von 3D-Modellierern und die Leistung allgemein zur Verfügung stehender Rechnersysteme gestatten die Modellierung beliebiger Objekte in jeder nur denkbaren Fachdisziplin. Das potentielle Leistungsvermögen von 3D-Modellierern sollte Anreiz sein, sie so alltäglich einzusetzen, wie die etablierten Standardapplikationen. Die im Vortrag gezeigten Modelle umfassen ein kleines Spektrum der möglichen Anwendungsgebiete. Weder vom (Daten)Umfang noch von ihrem Kompliziertheitsgrad stellen sie etwas Besonderes dar. Sie sollen nur das Interesse für einen alltäglichen Einsatz von 3D-Modellierern wecken und eventuell vorhandenen Einsatzschwellen abbauen helfen. Die im Vortrag gezeigten Bildfolgen sind unter http://www.uni-weimar.de/animationen zu finden. KW - Dreidimensionales Modell KW - Anwendung Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5257 ER -