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In der heutigen Informationsgesellschaft sind alle Geschäftsprozesse in einem Unternehmen geprägt durch die Verwendung der vorhandenen Informations- und Kommunikationstechnologien. Diese haben zur Folge, dass Unternehmen mit einer wahren Flut an Informationen konfrontiert werden, die von extern und intern in das Unternehmen eingetragen wurden. Die erfolgreiche Beherrschung dieser Informationsflut bildet die Basis für das effektive Arbeiten im Unternehmen. Grundvoraussetzung hierfür ist vor allem ein harmonisches Zusammenspiel zwischen Mensch ↔ Organisation ↔ Technik. Dokumentenmanagementsysteme haben sich zur Aufgabe gemacht, den Anwender bei der technologischen Bewältigung dieser Aufgabenstellung zu unterstützen. Der hier vorgestellte Artikel zeigt die Probleme auf, die während der Umsetzung eines Dokumentenmanagementsystems auftreten können und konzentriert sich dabei besonders auf Kleinen und Mittleren Unternehmen (KMU) im Bauwesen. Charakteristisch für diese ist die Schwäche die eigenen Unternehmensstrukturen betriebswirtschaftlich aufzubereiten, woraus später bei einer technologischen Umsetzung schwerwiegende Probleme resultieren. Genau an diesem Punkt setzt der vorgestellte Artikel an und versucht den Zusammenhang zwischen Organisation und Technik herauszuarbeiten, um darauf aufsetzend einen allgemeingültigen Ansatz für die Umsetzung eines Dokumentenmanagementsystems zu liefern.
Die Sicherheit von Tragwerken hängt von der zuverlässigen Modellierung sämtlicher Tragwerksparameter ab. Üblicherweise werden diese Parameter als deterministische oder stochastische Größen beschrieben. Stochastische Größen sind Zufallsgrößen, die unscharfe Informationen über Tragwerksparameter mit Hilfe von Dichtefunktionen erfassen. Nicht alle unscharfen Tragwerksparameter lassen sich als Zufallsgrößen darstellen. Sie können jedoch als Fuzzy-Größen modelliert werden. Fuzzy-Größen beschreiben unscharfe Tragwerksparameter als unscharfe Menge mit Bewertungsfunktion (Zugehörigkeitsfunktion). Die Fuzzy-Modellierung im Bauingenieurwesen umfaßt die Fuzzifizierung, die Fuzzy-Analyse, die Defuzzifizierung und die Sicherheitsbeurteilung. Sie erlaubt es, Tragwerke mit nicht-stochastischen unscharfen Eingangsinformationen zu untersuchen. Nicht-stochastische Eingangsinformationen treten sowohl bei bestehenden als auch bei neuen Tragwerken auf. Die unscharfen Ergebnisse der Fuzzy-Modellierung gestatten es, das Systemverhalten zutreffender zu beurteilen; sie sind die Ausgangspunkte für eine neue Sicherheitsbeurteilung auf der Grundlage der Möglichkeitstheorie. Bei der Fuzzy-Analyse ist die alpha-Diskretisierung vorteilhaft einsetzbar. Bei fehlender Monotonie der deterministischen Berechnungen und unter Berücksichtigung der Nichtlinearität wird die Fuzzy-Analyse mit Optimierungsalgorithmen durchgeführt. Zwei Beispiele werden diskutiert: die Lösung eines transzendenten Eigenwertproblems und eines linearen Gleichungssystems. Die Systemantworten der Fuzzy-Analyse werden der Sicherheitsbeurteilung zugrunde gelegt. Für ausgewählte physikalische Größen werden Versagensfunktionen definiert. Diese bewerten die Möglichkeit des Versagens. Mit Hilfe von Min-max-Operationen der Fuzzy-Set-Theorie erhält man aus Versagensfunktion und Fuzzy-Antwort die Versagensmöglichkeit bzw. die Überlebensmöglichkeit. Die ermittelte Versagensmöglichkeit repräsentiert die subjektive Beurteilung der Möglichkeit, daß das Ereignis &qout;Versagen&qout; eintritt. Beispiele zeigen die Unterschiede zwischen der Sicherheitsbeurteilung mittels Fuzzy-Modells und mittels deterministischen Modells.
Assuring global consistency in a cooperative working environment is the main focus of many nowaday research projects in the field of civil engineering and others. In this paper, a new approach based on octrees will be discussed. It will be shown that by the usage of octrees not only the management and control of processes in a network-based working environment can be optimised but also an efficient integration platform for processes from various disciplines – such as architecture and civil engineering – can be provided. By means of an octree-based collision detection resp. consistency assurance a client-server-architecture will be described as well as sophisticated information services for a further support of cooperative work.
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.
This paper presents the combination of two different parallelization environments, OpenMP and MPI, in one numerical simulation tool. The computation of the system matrices and vectors is parallelized with OpenMP and the solution of the system of equations is done with the MPIbased solver MUMPS. The efficiency of both algorithms is shown on several linear and nonlinear examples using the Finite Element Method and a meshless discretization technique.
In this paper a meshless component is presented, which internally uses the common meshless interpolation technique >Moving Least Squares<. In contrast to usual meshless integration schemes like the cell quadrature and the nodal integration in this study integration zones with triangular geometry spanned by three nodes are used for 2D analysis. The boundary of the structure is defined by boundary nodes, which are similar to finite element nodes. By using the neighborhood relations of the integration zones an efficient search algorithm to detected the nodes in the influence of the integration points was developed. The components are directly coupled with finite elements by using a penalty method. An widely accepted model to describe the fracture behavior of concrete is the >Fictitious Crack Model< which is applied in this study, which differentiates between micro cracks and macro cracks, with and without force transmission over the crack surface, respectively. In this study the crack surface is discretized by node pairs in form of a polygon, which is part of the boundary. To apply the >Fictitious Crack Model< finite interface elements are included between the crack surface nodes. The determination of the maximum principal strain at the crack tip is done by introducing an influence area around the singularity. On a practical example it is shown that the included elements improve the model by the transmission of the surface forces during monotonic loading and by the representation of the contact forces of closed cracks during reverse loading.
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.
Digital maps are very easily applied as route guide maps. Route guide maps are provided through Web or a mobile phone services, and demand for such services is increasing. However, the production of a route guide map requires a great deal of time. Therefore, it is difficult for general users to make route guide maps. The purpose of the present research is the development of a system that can generate a route guide map using the Digital Map 2500 (Spatial Data Framework) published by the Geographical Survey Institute. This system will not require advanced equipment or expert knowledge. Therefore, anyone can produce route guide maps easily and quickly. By using the Digital Map 2500, the time and cost required in order to generate a map are reduced. Moreover, a useful route guide map can be created by simplifying the map form based on the human cognitive map.
This paper describes the concept and experiences of the international Open Distance Learning Course ‘HydroWeb’. This course deals with the introduction of Web-based Collaborative Engineering in standard education programmes of water related engineering and civil engineering based on information sharing. Organized under the umbrella of IAHR and ETNET21 this course is collaboration from several universities from all over the world. Started in 1999 the course demonstrates the potential and innovative opportunities of Web-Technology in education, research and engineering: Students from the different partner universities form small distributed teams to solve a given engineering problem in a time window of two weeks. To overcome the spatial distribution the students apply modern Web technology such as video conferencing, application sharing and document management. All results as well as the final reports are presented as Web document on a shared Web-based project platform (http://www.hydro-web.org). Besides the experiences to apply standard Web tools and working methods based on information sharing instead the conventional information exchange in the daily engineering work the students improve their soft skills operate successfully in international and interdisciplinary project environments as part of the ‘Technical Culture’ of nowadays.
The availability of the WWW technology and the introduction of the Internet as basic resource like water, electricity or gas changes dramatically normal live, business and of course civil engineering. New technologies enable innovative technical solutions and offer new potential for improvements towards support of humans nature appropriate ways of working. This demands a new culture of work and collaboration. To contribute to theses challenges is a matter the discipline 'Bauinformatik' by supporting related research, development, education and training in civil engineering. This contribution to the IKM Conference 2000 in Weimar sketches selected research and education activities of the institutes of the authors on the topics of WWW based simulation systems (example WEASEL) and of WWW based project platforms (projects MorWin and TaiGer as well as an European education experiment). Both topics supports the collaboration by new ways of tele cooperation in international, heterogeneous and interdisciplinary engineering. Demonstration from this developments and projects will be used to illustrate the dimension of changes in civil engineering in due to modern ICT.
This paper describes the concept, implementation and application of the Web-based Information System ‘Turtle’ for data monitoring, analysis, reporting and management in engineering projects. The system uses a generalised object-oriented approach for information modelling of physical state variables from measurements and simulations by sets of tensor objects and is implemented platform-independently as a Web application. This leads to a more flexible handling of measurement and simulation information in distributed and interdisciplinary engineering projects based on the concept of information sharing. The potential and advantages of Web-based information systems like ‘Turtle’ are described for one selected application example: a measurement programme dealing with the physical limnology of Lake Constance.
Die Bauwerksüberwachung gewinnt aus sicherheitstechnischen sowie aus wirtschaftlichen Gründen zunehmend an Bedeutung. Nicht nur die Bauwerkssicherheit kann durch leistungsfähige Monitoring-Systeme angemessen beurteilt, auch die Nutzungsdauer bestehender Bauwerke kann durch die gewonnenen Informationen deutlich verlängert werden. Das vorliegende Papier beschreibt die Entwicklung eines webbasierten Talsperren-Monitoring-Systems, das die automatisierte Erfassung von Daten vor Ort sowie die computergestützte Aufbereitung und Analyse der gesammelten Messdaten ermöglicht. Das Monitoring-System ist durch seinen modularen Aufbau nicht auf die Talsperren-Überwachung beschränkt, sondern kann ohne großen Aufwand an andere Überwachungsaufgaben angepasst werden. Das System besteht aus drei wesentlichen Modulen: (i) einer erweiterbaren Klassenbibliothek, die die Steuerung der im Bauwerk installierten Messelektronik ermöglicht, (ii) einem webbasierten Datenerfassungsmodul, das neben der automatischen Datenerfassung eine Fernsteuerung der Messelektronik erlaubt und Funktionen zur Verwaltung der Überwachungsaufgaben bereitstellt, sowie (iii) einem webbasierten Visualisierungs- und Auswertungsmodul zur Aufbereitung und Analyse der gesammelten Daten. Alle an der Überwachung beteiligten Mitarbeiter können mit einem üblichen Web-Browser über das Internet auf das entwickelte System zugreifen; ein Zugriff mittels Mobiltelefon ist alternativ möglich. Das implementierte Talsperren-Monitoring-System begleitet die beteiligten Fachleute von der Erfassung der Daten vor Ort bis hin zur Aufbereitung und Analyse der Messdaten an zentraler Stelle: Die Mitarbeiter werden durch einen einfachen Zugriff auf die installierte Messelektronik, automatisierte Messungen und umfangreiche Analysefunktionalitäten bei ihren spezifischen Aufgaben unterstützt. Der bisherige manuelle Arbeitsaufwand für Datenerfassung, -transfer und Analyse wird somit deutlich reduziert.
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.
The displacements and stresses in arch dams and their abutments are frequently determined with 20-node brick elements. The elements are distorted near the contact plane between the wall and the abutment. A cantilever beam testbed has been developed to investigate the consequences of this distortion. It is shown that the deterioration of the accuracy in the computed stresses is significant. A compatible 18-node wedge element with linear stress variation is developed as an alternative to the brick element. The shape of this element type is readily adapted to the shape of the contact plane. It is shown that the accuracy of the computed stresses in the vicinity of the contact plane is improved significantly by the use of wedge elements.
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.
In the AEC (Architecture / Engineering / Construction) industry a number of individuals and organisations collaborate and work jointly on a construction project. The resulting consortium has large pool of expertise and experience and can be defined as a Virtual Organisation (VO) formed for the duration of the project. VOs are electronically networked organisations where IT and web based communication technology play an important role in coordinating various activities of these organisations. This paper describes the design, development and implementation of a Grid enabled application called the Product Supplier Catalogue Database (PSCD) which supports collaborative working in consortia. As part of the Grid-enabling process, specialised metadata is being developed to enable PSCD to effectively utilise Grid middleware such as Globus and Java CoG toolkits. We also describe our experience whilst designing, developing and deploying the security service of the application using the Globus Security Interface (GSI).
At the start of the conceptual design process, designers start to give tangible form to their thoughts by sketching. This helps with reasoning and communicates ideas to other members of the team. Sketches are gradually worked up into more formal drawings which are then passed to the other stages of the design process. There are however some problems with basing early ideas on sketching. For example, due to their ad-hoc nature, sketches tend only to be diagrammatic representations and so designers cannot be sure that their ideas are feasible and what is being proposed meets the constraints described in the client brief. This can result in designers wasting time working up ideas which prove to be unsuitable. Also the process of constraint checking is complex and time consuming and so designers tend limit their search of possible options and instead choose satisfying rather than good solutions. This paper describes the INTEGRA project which examines the role of sketching in early conceptual design and how this can be linked to other aspects of the process and particularly automated constraint checking using an IT based approach. The focus for the work is the design of framed buildings. A multi-disciplinary approach has been adopted and the work has been undertaken in close collaboration with practising designers and clients.
Die Methode der Finiten Elemente ist ein numerisches Verfahren zur Interpolation vorgegebener Werte und zur numerischen Approximation von Lösungen stationärer oder instationärer partieller Differentialgleichungen bzw. Systemen partieller Differentialgleichungen. Grundlage dieser Verfahren ist die Formulierung geeigneter Finiter Elemente und Finiter Element Zerlegungen. Finite Elemente besitzen in der Regel eine geometrische Basis bestehend aus Strecken im eindimensionalen, Drei- oder Vierecken im zweidimensionalen und Tetra- oder Hexaedern im dreidimensionalen euklidischen Raum, eine Menge von Freiheitsgraden und eine Basis von Funktionen. Die geometrische Basis eines Finiten Elements wird verallgemeinert als geometrische Zelle formuliert. Diese geschlossene geometrische Formulierung führt zu einer geometrieunabhängigen Definition der Basisfunktionen eines Finiten Elements in den Zellkoordinaten der geometrischen Zelle. Finite Elemente auf der Basis geometrischer Zellen werden als Bestandteile Finiter Element Zerlegungen in Finiten Element Interpolationen und Finiten Element Approximationen verwendet. Die Finiten Element Approximationen werden am Beispiel der 2-dimensionalen Diffusionsgleichung über das Standard-Galerkin-Verfahren ermittelt.
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...
Numerische Approximation makroskopischer Verkehrsmodelle mit der Methode der Finiten Elemente
(2000)
Makroskopische Verkehrsmodelle sind ein wesentliches Hilfsmittel bei der Beurteilung und Steuerung von Verkehrsflüssen auf Hauptverkehrsadern. Für die notwendige Beeinflussung des Verkehrsablaufs werden Online-Messungen und prognostische numerische Simulationen benötigt. Für die Simulationen bieten sich makroskopische Verkehrsmodelle an, die den Verkehr als kontinuierliche Fahrzeugströmeabbilden. Aufgrund der Analogie zu den Modellen der Strömungsmechanik lassen sich die numerischen Verfahren aus diesem Bereich auch zur Lösung makroskopischer Verkehrsmodelle verwenden. Es wird eine Finite-Elemente-Approximation für die numerische Umsetzung makroskopischer Verkehrsmodelle vorgestellt. Exemplarisch wird sie am Verkehrsmodell von Kerner und Konhäuser erläutert. Dieses und andere makroskopische Verkehrsmodelle wurden bisher mit der Methode der Finiten Differenzen gelöst. Die vorgestellte Approximation entspricht einem Petrov-Galerkin-Verfahren, bei dem der Fehler eines Standard-Galerkin-Verfahrens mit Hilfe eines Upwinding-Koeffizienten minimiert wird. Die Wahl des Upwinding-Koeffizienten ist übertragbar und basiert ausschließlich auf dem Charakter der zugrundeliegenden Gleichungen. Die Ergebnisse zeigen typische Phänomene eines Verkehrsablaufs wie die Entstehung von Stop-and-Go-Wellen oder Staus. Die Finite-Elemente-Methode erweist sich für unter-schiedlichste Verkehrsmodelle als ausgesprochen stabil.
Hydro- und morphodynamischen Prozesse in Binnengewässern und im Küstennahbereich erzeugen hochkomplexe Phänomene. Zur Beurteilung der Entwicklung von Küstenzohnen, von Flussbetten sowie von Eingriffen des Menschen in Form von Schutzbauwerken sind geeignete numerische Modellwerkzeuge notwendig. Es wird ein holistischer Modellansatz zur Approximation gekoppelter Seegangs-, Strömungs- und Morphodynamischer Prozesse auf der Basis stabilisierter Finiter Elemente vorgestellt. Der Großteil der Modellgleichungen der Hydro- und Morphodynamik sind Transportgleichungen. Dem Transportcharakter dieser Gleichungen entsprechend wird ein stabilisiertes Finites Element Verfahren auf Dreiecken vorgestellt. Die vorgestellte Approximation entspricht einem streamline upwinding Petrov-Galerkin-Verfahrens für vektorwertige mehrdimensionale Probleme, bei dem der Fehler eines Standard-Galerkin-Verfahrens mit Hilfe eines Upwinding-Koeffizienten minimiert wird. Die Wahl des Upwinding-Koeffizienten ist übertragbar auf andere Problemklassen und basiert ausschließlich auf dem Charakter der zugrundeliegene Das Modell wurde für Seegangs- und Strömungs-Untersuchungen im Jade-Weser-Ästuar an der deutschen Nordseeküste eingesetzt.
Die Verfügbarkeit und die sichere Beherrschung moderner und kostengünstiger Informations- und Kommunikationstechnologien gestattet es auch kleinen unternehmerischen Einheiten im Bauwesen sich in betriebsübergreifenden Netzwerken zu organisieren und sich besser in die Wertschöpfungskette am Bau zu integrieren. In sogenannten >Virtuellen Organisationen< (VO) können diese für die Volkswirtschaft wichtigen Unternehmen ihre Wettbewerbsvorteile wie höhere Flexibilität, schnelle Reaktion auf Kundenwünsche und Marktnähe nutzen und somit ihr langfristiges Bestehen in einem liberalen Wettbewerb auf einem erweiterten EU-Markt sichern und ausbauen. Die derzeit existierenden Hindernisse im Informationsfluss zwischen Baustelle und Büro können durch den Einsatz mobiler, funkvernetzter Endgeräte, wie beispielsweise >Smart-Phones<, und einer neu zu gestaltenden Infrastruktur zum Wissensmanagement und zur kontextsensitiven Informationsdarstellung abgebaut werden. Im Rahmen dieser Veröffentlichung werden konzeptionelle Ansätze eines integrierten Informationsmanagements zur Unterstützung von VO, die im Rahmen des BMBF-Projektes >IuK-System Bau< derzeit entwickelt werden, vorgestellt.
We provide a critical overview of the current status of computational support for construction the management and building performance evaluation in North-America. This overview is based on the research conducted in relation to the design and construction of the Intelligent Workplace (IW), Carnegie Mellon University, Pittsburgh, Pennsylvania, USA. With regard to the commercial software products in the field of construction management the following limitations can be identified: Although project planning, cost estimating and construction simulation are supported, tasks like bidding as well as site and material management have not received the same level of attention. Few project management software packages are integrated in a total design support software system. Little analysis or evaluation options are provided to support managerial decision making. Various research groups address the construction planning and scheduling, construction contracting, site layout generation as well as the integration of these three topics. Currently problems such as efficient material management and calculation of environmental and energy responsive site management are insufficiently addressed within the ongoing research projects. In the domain of building performance simulation and decision support one can notice that, the development and application of computational tools is industry driven. As a result the concerns addressed by the tools are mainly issues pertaining to the selection and sizing of systems and components rather than an integrated performance evaluation. Consequently, these programs are rarely used by building designers, especially in the early design stages, where the predictive capabilities of simulation tools could be of significant value. Although many research institutions address the necessity for the integration of performance simulation within the overall design support environments most of the practically available performance simulation tools still remain mono-dimensional and isolated.
Processing technical and environmental data on building materials, components, and systems has become more important during the last few years. Increased sensitivity towards environmental and energy problems has lead to the demand for simulation and evaluation of the long term behavior of buildings. The results of such simulations are expected to enable architects and engineers to develop a broader, interdisciplinary understanding of the impact of their products (buildings) on the environment. However, conducting such evaluations is currently hampered by the lack of comprehensive, up-to-date, and ecologically relevant data on building materials, components, and systems. To address this problem, this paper proposes an approach to deal with the absent or uncertain attributes of building materials, components, and systems. In the past, various information systems have been developed to provide data on a limited set of building materials, including precise values pertaining to some of their characteristics, such as availability, manufacturers, costs, etc. These traditional information systems have difficulty in dealing with uncertain, incomplete and sparse data. However, uncertainty and incompleteness characterize the nature of most of the available and environmentally related characteristics of materials, components, and systems. In this paper, a fuzzy-logic-based augmentation of traditional information systems is proposed towards providing management, utilization and manipulation of incomplete and uncertain data.
The AEC industry is conscious of the potentials arising from the usage of mobile computer systems to increase productivity by streamlining their business processes. Discussions are no longer on whether or not to use a mobile computer solution, but rather, on how it should be used. However, the implantation process of this new technology in Architecture, Engineering and Construction (AEC) and Facility Management (FM) practise is very slow and should be improved. One way to encourage and ease the usage of mobile computer systems in AEC is a more process-oriented usability and context appropriateness of mobile computer solutions. Context-sensitivity is defined as a crucial feature to be taken into account for further research in the area of Mobile Computing. Context-sensitive, mobile IT-solutions depend on two features: (1) flexible definitions of (construction) processes describing the context and (2) tools for flexible, multi-dimensional information management representing the context. It is on this premise that the authors propose the n-dimensional data management approach for the implementation of mobile computing solutions. In this paper, we analyse working scenarios in the AEC and FM sector, defining context aspects which are transformed and formalized as dimension hierarchies of the envisaged context model.
Creation of hierarchical sequence of the plastic and viscoplastic models according to different levels of structure approximations is considered. Developed strategy of multimodel analysis, which consists of creation of the inelastic models library, determination of selection criteria system and caring out of multivariant sequential clarifying computations, is described. Application of the multimodel approach in numerical computations has demonstrated possibility of reliable prediction of stress-strain response under wide variety of combined nonproportional loading.
The phenomenological and computational aspects of the various damage models applications for the low and multi cyclic fatigue processes are investigated. Damage is considered as internal state variable, describing macroscopic effects of the progressive material degradation, within the framework of continuum damage mechanics. Present analysis is restricted to the case of isotropic damage, which can be modeled by a scalar variable. The strain, force and power types of kinetic equations for the damage evolution description are considered. The original mixed strain-power type damage model is developed for taking into account the different physical fracture mechanism in monotone and cyclic loading. The constitutive equations of plastic flow theory coupled and uncoupled to damage has been considered. The rational algorithm of implementation into finite element code is considered for developed damage models. Set of the computational experiments has been carried out for the various structures (huge aerials, pipelines, fastening units, vessel of nuclear reactor) and cases of loading. The comparison of the predictions of the developed model with experimental data is performed for 1X18H10T steel tubular specimens for complex paths of loading and for complex profiles beams under cyclic loading. Damage field distribution is the basic information for the prediction of crack initiation in structures. The developed method of structural parameter for stress concentration zones is discussed for correcting of crack location. It allows to describe the crack initiation near surface domain as observe in numerous experiments.
The research reported in this article was conducted to mainly explore the two common numeric prediction techniques, the model tree and the regression tree, when used in conjunction with bagging as a wrapper method. Bagging is used to improve the prediction accuracy of these two algorithms, and results are compared with the ones obtained earlier by the k-nearest neighbor (KNN) algorithm. From the conducted experiments, both the bagged regression tree and bagged model tree produce better results than not only their corresponding regression tree and model tree alone, but also the KNN with optimal value of k equal to 7. In addition, the bagged model tree yields the lowest prediction errors and a highest correlation coefficient of 0.81. It is demonstrated that it is feasible to use the bagged model tree for engineering applications in prediction problems such as estimating the remaining service life of bridge decks.
Building design in Civil Engineering is characterized by the cooperation of experts in multiple disciplines. Close cooperation of engineers in different fields is the basis of high product quality, short development periods and a minimum of investment costs. For each building the engineers have to create a new fire engineering model. The consistent realization of the fire engineering model in all details has high demands on communication, collaboration and building models. Thereby, to preserve the related design models consistent to each other and compatible with the rules of fire engineering is a complex task. In addition, regulations and guidelines vary according to the building location, so the knowledge base must be integrated dynamically into the planning process. This contribution covers the integration of engineers and design models into a cooperation network on the basis of mobile agents. The distributed models of architectural design, structural planning and fire engineering are supported. These models are implemented as XML-based models which can be accessed by mobile agents for information retrieval and for processing tasks. Agents are provided to all planners, they are enabled to check up the distributed design models with the knowledge base of the fire protection regulations,. With the use of such an agent each planner is supported to check up his planning for accordance with the fire protection requirements. The fire-engineering-agent analyzes the design and detects inconsistencies by processing fire protection requirements and design model facts in a rule-based expert system. The possibility to check the planning information at an early state in the sense of compatibility to the fire protection regulations enables a comprehensive diagnosis of the design and the reduction of planning errors.
In Anbetracht der leistungsstarken Computernetzwerke und der intensiven Globalisierung von Wissenschaft und Technik im Bauwesen ist es das Ziel der Bauinformatik, die Planungsprozesse des Konstruktiven Ingenieurbaus für die Nutzung verteilter Ressourcen zu gestalten, geeignete Kooperationsmodelle für die Fachplanung im Informationsverbund der Projektbeteiligten zu entwickeln und die kooperative Projektbearbeitung unter Nutzung verteilter Fachmodelle in Netzen zu ermöglichen. Dazu werden neue methodische Grundlagen geschaffen, welche die tiefgreifenden Veränderungen der Arbeits- und Organisationsstrukturen berücksichtigen. Vor diesem Hintergrund zeigt der Beitrag aktuelle Forschungsinhalte der Bauinformatik auf, die insbesondere im Rahmen des DFG-Schwerpunktprogramms 1103 'Vernetzt-kooperative Planungsprozesse im Konstruktiven Ingenieurbau' von verschiedenen Projekten arbeitsteilig entwickelt werden. Es wird ein integratives Prozessmodell vorgestellt, das die Grundlage für die Unterstützung der vernetzt-kooperativen Planung mit modernen Methoden der Informationsverarbeitung und Kommunikationstechnik zusammenführt. An einem Beispiel aus dem baulichen Brandschutz werden die methodischen Ansätze der Prozessmodellierung mit Petri-Netzen und der mobilen Softwareagenten zur Unterstützung der Kooperation in der Fachplanung des Bauwesens dargestellt und erläutert.
The US Department of Highways is embarked on a very ambitious program to renovate much of the bridges and highways allover the USA. While it is doing so, it is also trying to take advantage of using such program to enhance the research for future programs. One of those projects is a 1000 ft. (305 m) long concrete bridge in the State of Vermont, located in the North East of USA. It is scheduled for renovation, in which the deck and its side parapet walls will be replaced. New England Transportation Consortium (NETC) decided to make further use of this project to find what effect will the heavy demolition tools have on the concrete to remain in place. The goal is to find out the extent of the experimental measurement agreement with the analytical results. In order to accomplish such a goal, numerous strain gages were installed at and in the vicinity of the demolition areas. Those gages will measure the effect of the demolition on the adjacent areas, and how far the destructive effect of the powerful demolition tools can propagate through different parts of the structure. The gages are connected to National Instruments data acquisition equipment, which is connected to a lap top computer to save all the acquired data. The analytical part the project will be using the energy method, which means that the energy applied by the demolition tools should equal the energy absorbed by the demolished structure, in elastic and plastic deformation forms.
In der vorliegenden Arbeit geht es um die Anwendung von biorthogonalen Waveletsystemen in der Parameteridentifikation. Es sollen Grundlagen geschaffen werden, um bei der Auswertung dynamischer Experimente derartige Wavelets und damit die schnelle Wavelet-Transformation (FWT) systematisch und effektiv zu nutzen. Zu diesem Zweck wird von den Waveletfiltern ein System von Verbindungskoeffizienten abgeleitet. Mit deren Hilfe erfolgen die Projektionen von Operatoren, insbesondere die von Differentiations- und Integrationsoperatoren, in die entsprechenden Wavelet-Räume. Sämtliche Verbindungskoeffizienten können rekursiv und in endlich vielen Schritten exakt berechnet werden. Ausgehend von den dynamischen Krafteinwirkungen und den gemessenen Reaktionsbeschleunigungen oder Reaktionsgeschwindigkeiten bezüglich der einzelnen Freiheitsgrade können dann unbekannte Steifigkeiten und Dämpfungen identifiziert werden. Dazu erfolgt nach entsprechenden Wavelet-Zerlegungen aller relevanten Zeitsignale ein Abgleich auf den einzelnen Frequenzbändern. Dieser führt insbesondere zu einem System von linearen Matrizengleichungen zur Bestimmung der unbekannten Parameter. Vorgeschlagen wird im Falle einer größeren Zahl von Freiheitsgraden und Parametern, ein mehrstufiges Optimierungsverfahren anzuwenden. Gegenüber Identifikationsverfahren im Zeitbereich werden aufwendige numerische Quadraturverfahren und die daraus resultierenden Fehlerquellen und Stabilitätsprobleme vermieden. Gegenüber Verfahren im Frequenzbereich, die ausschließlich mit Hilfe der FFT formuliert werden, sind Störungen in den Randspektren besser beherrschbar und eliminierbar. Außerdem werden mit einem FWT-Verfahren einfachere Denoising-Algorithmen anwendbar. Letztendlich wird im Vergleich zu einem FFT-Verfahren ein späterer Übergang zur Identifikation nichtlinearer MDOF-Systeme methodisch erleichtert.
After more than hundred years of arguments in favour and against quaternions, of exciting odysseys with new insights as well as disillusions about their usefulness the mathematical world saw in the last 40 years a burst in the application of quaternions and its generalizations in almost all disciplines that are dealing with problems in more than two dimensions. Our aim is to sketch some ideas - necessarily in a very concise and far from being exhaustive manner - which contributed to the picture of the recent development. With the help of some historical reminiscences we firstly try to draw attention to quaternions as a special case of Clifford Algebras which play the role of a unifying language in the Babylon of several different mathematical languages. Secondly, we refer to the use of quaternions as a tool for modelling problems and at the same time for simplifying the algebraic calculus in almost all applied sciences. Finally, we intend to show that quaternions in combination with classical and modern analytic methods are a powerful tool for solving concrete problems thereby giving origin to the development of Quaternionic Analysis and, more general, of Clifford Analysis.
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.
Ideally, multiple computational building evaluation routines (particularly simulation tools) should be coupled in real-time to the representational design model to provide timely performance feed-back to the system user. In this paper we demonstrate how this can be achieved effectively and conveniently via homology-based mapping. We consider two models as homologous if they entail isomorphic topological information. If the general design representation (i.e., a shared object model) is generated in a manner so as to include both the topological building information and pointers to the semantic information base, it can be used to directly derive the domain representations (>enriched< object models with detailed configurational information and filtered semantic data) needed for evaluation purposes. As a proof of concept, we demonstrate a computational design environment that dynamically links an object-oriented space-based design model, with structurally homologous object models of various simulation routines.
There are many construction projects in China and mass documents are exchanged among the multi-party, including the owner, the contractor and the engineer in the projects. Based on previous studies, an approach to the utilization of the exchanged documents is established by using data warehouse technology and a prototype system called EXPLYZER is developed. The approach and the prototype system are verified through their application in a construction project. It is concluded that the approach can support the decision-making in project management.
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.
Plausibilität im Planungsprozess - Digitale Planungshilfen für die Bebaubarkeit von Grundstücken
(2003)
Die digitale Unterstützung der Planungsprozesse ist ein aktueller Forschungs- und Arbeitsschwerpunkt der Professur Informatik in der Architektur (InfAR) und der Juniorprofessur Architekturinformatik der Fakultät Architektur an der Bauhaus-Universität Weimar. Verankert in dem DFG Sonderforschungsbereich 524 >Werkzeuge und Konstruktionen für die Revitalisierung von Bauwerken< werden Konzepte und Prototypen für eine fachlich orientierte Planungsunterstützung entwickelt. Die Vielfalt der unterschiedlichen Faktoren, die Einfluss auf den Planungsprozess nehmen können, sowie deren Abhängigkeiten voneinander werden von heutigen Planungssystemen in nur unzureichender Weise aufbereitet und verwaltet. Diese Faktoren bedingen Planungstools, deren Aufgabe die Beschaffung, Verarbeitung, Integration und Verwaltung von Informationen sowie die Veranschaulichung der komplexen Informationszusammenhänge ist. Die Entwicklung solcher Systeme ist technisch möglich. Die Schwierigkeit liegt in der Beschaffung und Strukturierung der für den Planungsprozess relevanten Informationen sowie in ihrer Aufbereitung und Integration in eine digitale Planungsumgebung. Das Bestreben des Forschungsprojektes ist es, Grundlagen für digitale Werkzeuge zu entwickeln die zu plausiblen Lösungen im Planungsprozess und somit zu erhöhter Planungssicherheit für die am Bau beteiligten Auftragnehmer und Auftraggeber führen. Es wird angestrebt Programm-Module zu entwickeln, die den Planer bei der Ermittlung von Lösungswegen zu einer Fachfrage inhaltlich unterstützen und die Nachvollziehbarkeit und Richtigkeit einer Planungsentscheidung gewährleisten und plausibel darlegen. Mit Hilfe der Module sollen Entscheidungsfindungen katalysiert werden. Die Bauvorhaben der Zukunft werden zu einem großen Teil im Bestand liegen. Dieses Faktum erfordert planerische Maßnahmen, für die vollends Werkzeuge und Hilfsmittel fehlen, die zu plausiblen und sicheren Planungsentscheidungen führen. Die Entwicklung solcher Hilfsmittel ist Ziel dieser Forschung. Der Beitrag stellt prototypische Software-Module vor, die sich mit der Problematik der potenziellen Bebaubarkeit einer Grundstücksfläche auseinander setzen. Die Module verarbeiten Regeln, die den einschlägigen Normen und Verordnungen entnommen sind, die bei der Erarbeitung einer Planungslösung eingehalten werden müssen.
Bei der Gründung von schweren Bauwerken (z.B. Hochhäusern auf Gründungsplatten und pfählen) wird der Lastabtrag in den Baugrund durch eine starke Interaktion zwischen Bauwerk und Baugrund bestimmt. Der Baugrund kann phänomenologisch als Mehrphasenkontinuum beschrieben werden, bei dem die Phasen Feststoff, Flüssigkeit und Gas in mechanische Wechselwirkung treten. Die Wechselwirkung zwischen der Deformation des Feststoffes und der Strömung des Porenwassers spielt unter der Lasteinwirkung des Bauwerks und unter dynamischer Erregung eine zentrale Rolle. Bei komplexen Gründungsverhältnissen können die Deformations- und Spannungszustände realitätsnah nur durch dreidimensionale Modelle erfasst werden. Je nach Baufortschritt stellen sich die Probleme dabei unterschiedlich dar. Der vorliegende Beitrag beschäftigt sich mit der für die mit der Simulation mit der Methode der finiten Elemente notwendigen Modellierung und der rechnergestützten Netzgenerierung für die Baugrund-Tragwerk-Strukturen. Bei komplexen dreidimensionalen Gründungskonstruktionen ist eine solche rechnergestützte Diskretisierung mit finiten Elementen zweckmäßig, die das geotechnische System und dessen Randbedingungen und Lasten umfassend beschreiben und verwalten kann. Dafür werden geeignete Software-Werkzeuge vorgestellt, mit denen sich dreidimensionale, zeitabhängige Systeme modellieren und diskretisieren lassen. Die Kontaktproblematik zwischen Baugrund und Tragwerk und die Besonderheiten des Mehrphasenkontinuums stellen besondere Ansprüche an die Diskretisierung. Zudem werden Methoden vorgestellt, die das akkumulierte Gründungsmodell, das sich über den Bauablauf ergibt, verwalten und die verschiedenen Bauzustände in einem dynamischen Modell bereitstellen.
Parallele Netzgenerierung
(1997)
Bei der Berechnung von statischen oder dynamischen Problemen mit Hilfe der Methode der Finiten Elemente ist eine Diskretisierung des zu berechnenden Gebietes notwendig. Bei einer sinnvollen Modellierung des Gebietes ist die Elementgröße meist nicht konstant, sondern ist an kritischen Stellen kleiner. Die Vorgaben hierfür können einerseits aus Erfahrungen des Anwenders, andererseits aus einer Fehlerabschätzung einer vorangegangenen FE-Berechnung resultieren [5]. Soll die FE-Berechnung auf einem Parallelrechner geschehen, ist eine Partitionierung des Gebietes, d.h. eine Zuordnung der Elemente zu den Prozessoren, notwendig. Bei dem hier beschriebenen Ansatz werden nun im Gegensatz zu den üblichen Verfahren erst die Eingangsdaten für den Netzgenerator umgewandelt und dann das Elementnetz direkt auf dem Parallelrecher gleichzeitig auf allen Prozessoren erzeugt. Eine Aufteilung der Elemente auf die Prozessoren entsteht als Nebenprodukt der Netzaufteilung. Die entstehenden Teilgebietsgrenzen werden geometrisch minimiert. Die Lastbalance der Netzaufteilung sowie der FE-Rechnung wird durch ein annähernd gleiche Anzahl der Elemente je Partition gewährleistet. Als Eingabedaten wird eine Beschreibung des Gebietes durch Polygonzüge, sowie einer Netzdichtefunktion, z.B. durch Punkte mit Angaben über die angestrebte Elementgröße, benötigt.
In this contribution, the design of an analysis environment is presented, that supports an analyst to come to a decision within a gradual collaborative planning process. An analyst represents a project manager, planner or any other person, involved in the planning process. Today, planning processes are managed by several geographically distributed planners and project managers. Thus, complexity of such a process rises even more. Prediction of consequences of many planning decisions is not possible, in particular since assessment of a planning advance is not trivial. There have to be considered several viewpoints, that depend on individual perceptions. In the following, methods are presented to realize planning decision support.
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.
Advances in construction data analysis techniques have provided useful tools to discover explicit knowledge on historical databases supporting project managers’ decision making. However, in many situations, historical data are extracted and preprocessed for knowledge discovery based on time-consuming and problem-specific data preparation solutions, which often results in inefficiencies and inconsistencies. To overcome the problem, we are working on the development of a new data fusion methodology, which is designed to provide timely and consistent access to historical data for efficient and effective management knowledge discovery. The methodology is intended to be a new bridge between historical databases and data analysis techniques, which shields project managers from complex data preparation solutions, and enables them to use discovered knowledge for decision making more conveniently. This paper briefly describes the motivation, the background and the initial results of the ongoing research.
A vast growth of advanced information technology systems and tools nowadays is opening new ways to collect accurate as-built data. Since the turn of the millennium, new technology developments enable for the first time to gather accurate as-built information. Accurate as-built data will be of great usage to construction management as well as to designers and engineers. Given that most of the planned data are already digitally available, as-built data remains on paper forms. Information technology developments are opening new ways to digitize construction field data in order to develop intelligent tools for construction management allowing design engineers to update as-planned data. 3D Laser scanning, digital close-range photogrammetry and mobile computing are among the promising data collection technologies, which are auspicious to create new opportunities to develop advanced construction management and engineering tools. Primarily, accurate collected as-built data will be highly beneficial for the process of updating as-planned data.
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.
The failure mechanisms of textile reinforced concrete (TRC), which is a composite of bundles of long fibers and fine concrete, are complex. Most important for the ductility is the successive debonding of the fibers from the surrounding matrix when the brittle matrix is cracking. Therefore, one of the main issues is the simulation of the bond behavior between the reinforcement and the matrix. By introducing a hierarchical material model for TRC the mechanical behavior is simulated by means of representative volume elements modelled on the meso scale. Finite element analysis is used to determine the effective properties of TRC within a periodic homogenization framework. Further, a multiscale finite element technique is suggested, where constitutive equation are formulated only on the meso level.
Werden Bauwerke für eine begrenzte Lebensdauer ausgelegt, kann es sinnvoll sein, die Tragfähigkeit von Tragkonstruktionen zu überwachen, um Schäden zu vermeiden und eine sichere Funktionsweise zu gewährleisten. Die Überwachung, hier auf Basis von Schwingungen der Struktur, wird zumeist von einer rechnergestützten Messtechnik automatisch durchgeführt. Der Computer überprüft spezielle physikalische Kennwerte oder Kennfunktionen des Tragwerks auf Veränderungen. Eine Schädigung ruft eine Veränderung hervor. Aufgabe der Systemidentifikation ist es, eine solche Veränderung zu erkennen. Eine Modellbildung kann z.B. auf theoretischer Basis als Finite Element Modellierung, oder als Black Box Modellierung aus Messwerten mit der Methodik der deterministischen oder stochastischen Systemidentifikation vorgenommen werden. In diesem Aufsatz werden die Analyse allgemeiner deterministischer und stochastischer Erregungen und deren Schwingungsantworten zur Modellbildung und Systemidentifikation beschrieben. Als Anwendungsbeispiele für die Bauwerksüberwachung werden Methoden zur Schadens-Erfassung und -Lokalisation vorgestellt. Den Abschluss bilden Ausführungen zur numerischen Modellierung von Windlasten als stochastischen Prozess und der Kopplung dieser Modelle mit finiten Element-Modellen, um eine bessere Abschätzung der Lebensdauer eines Bauwerks schon im Entwurfsprozess zu ermöglichen.
Although there are some good reasons to design engineering software as a stand-alone application for a single computer, there are also numerous possibilities for creating distributed engineering applications, in particular using the Internet. This paper presents some typical scenarios how engineering applications can benefit from including network capabilities. Also, some examples of Internet-based engineering applications are discussed to show how the concepts presented can be implemented.
PKPM series CAD software is an integrated CAD system for building design, which integrated the following parts: architectural design, structural design, building service design and statistic analysis of quantity and budget. These four parts share the same database with high efficiency. Over 80% of design corporation in China are using PKPM series CAD software. The detailed information and some key modules of PKPM series CAD software are mainly introduced in this paper.
Framed-tube system with multiple internal tubes is analysed using an orthotropic box beam analogy approach in which each tube is individually modelled by a box beam that accounts for the flexural and shear deformations, as well as the shear-lag effects. A simple numerical modeling technique is proposed for estimating the shear-lag phenomenon in tube structures with multiple internal tubes. The proposed method idealizes the framed-tube structures with multiple internal tubes as equivalent multiple tubes, each composed of four equivalent orthotropic plate panels. The numerical analysis is based on the minimum potential energy principle in conjunction with the variational approach. The shear-lag phenomenon of such structures is studied taking into account the additional bending moments in the tubes. A detailed work is carried out through the numerical analysis of the additional bending moment. The moment factor is further introduced to identify the shear lag phenomenon along with the additional moment.
This paper describes a research project that addresses the difficulties in dealing with regulatory documents such as national and regional codes. These documents tend to be voluminous, heavily cross-referenced, possibly ambiguous and even conflicting at times. There are often multiple documents that need to be consulted and satisfied; however it is a difficult task to locate all of the relevant provisions. In addition, sections dealing with the same or similar conceptual ideas sometimes lay down conflicting requirements. We propose a framework for regulation representation, analysis and comparison with emphasis on the extraction of similarities between provisions. We focus on accessibility regulations, whose intent is to provide the same or equivalent access to a building and its facilities for disabled persons. An XML regulatory repository is developed to extract structural as well as non-structural features from government regulations to help user understanding and computational analysis. A similarity analysis is performed between different sources of regulations. In order to achieve a better comparison between provisions, we employ a combination of feature matching and structural analysis. Results are shown on comparisons between American and European codes, as well as on the domain of electronic-rulemaking.
Die Aufgaben des Bauingenieurwesens sind dadurch geprägt, daß sowohl die Planung als auch die Ausführung von Bauwerken häufigen Änderungen unterliegen. Beschreibt man das Verhalten der Bauwerke und den Bauprozeß im Computer mit Modellen, so ändern sich Umfang und Struktur der Modelle als Folge der Änderung in Planung und Ausführung. Diesen Vorgang nennt man Dynamisierung des Modells. Die Dynamisierung führt zu Veränderungen und Inkonsistenzen in den Modellen der Anwendungen. Die Aktualisierung und Abstimmung von Beziehungen innerhalb eines Modells sowie die Sicherung der Konsistenz der Modelle untereinander sind daher von zentraler Bedeutung für die Lösung von Bauingenieuraufgaben. Seit den letzten 10 Jahren wird die objektorientierte Methode in der Modellierung für Anwendungen im Bauingenieurwesen intensiv entwickelt und eingesetzt. Es hat sich gezeigt, daß die Anwendung dieser Methode in wichtigen Bereichen der Modellierung zu Verbesserungen führt. Gleichzeitig hat sich aber auch herausgestellt, daß die für das Bauingenieurwesen wichtigen Aspekte der Aktualisierung und der Konsistenz nicht zweckmäßig beschreibbar sind. In diesem Beitrag wird eine einfache Modelliermethode in ihrem Konzept und ihrer Realisierung gezeigt, mit der sich die Aktualisierung von Objekten und Modellen sowie die Sicherstellung der Konsistenz in Systemen des Bauingenieurwesens bearbeiten lassen.
Wirklichkeitsnahe Erfassung und Beschreibung des Trag- und Verformungsverhaltens von Strukturen baulicher Anlagen hat in den letzten Jahrzehnten ständig an Bedeutung gewonnen. Konstruktionen im Hoch- und Industriebau werden zunehmend multifunktional genutzt - die >Grenzen< zwischen Bauwerk und Tragwerk, zwischen Hüll- und Tragkonstruktion lösen sich auf. Werden raumabschließende Elemente (Wände, Decken, Dächer) gleichzeitig als Tragelemente und wärme- und schalldämmende Konstruktionen ausgeführt, so entstehen beispielsweise Sandwichplatten, deren Schichten sehr stark differierende Materialeigenschaften aufweisen. Beim Aufbau des FEM-Modells für vielschichtige Schalen können die Formänderungshypothesen für jede Schicht einzeln als auch für die Schale insgesamt gegeben werden. Im ersten Fall ist der Knotenfreiheitsgrad von der Schichtenzahl abhängig, im zweiten Fall nicht. Im weiteren wird eine Formänderungshypothese für das Schichtenpaket angenommen. Ausgegangen wird von den Gleichungen der 3D-Elastizitätstheorie. Die Berücksichtigung der Querkraftschubverformungen ergibt die Möglichkeit einer adäquaten Beschreibung der Verformungen sowohl dünner Schalen als auch von Schalen mittlerer Dicke; die Berechnung der Krümmungen und der LAMEschen Parameter der Bezugsfläche zu umgehen, was für komplizierte Schalenformen eine selbständige Aufgabe ist; eines natürlichen Übergangs von homogenen zu geschichteten Schalen. Das vielschichtige isoparametrische Schalen-FE wird vorgestellt, seine Implementierung in das in Entwicklung befindliche Programmsystem SLANG wird vorbereitet.
The planning of projects in building engineering is a complex process which is characterized by a dynamical composition and many modifications during the definition and execution time of processes. For a computer-aided and network-based cooperation a formal description of the planning process is necessary. In the research project “Relational Process Modelling in Cooperative Building Planning” a process model is described by three parts: an organizational structure with participants, a building structure with states and a process structure with activities. This research project is part of the priority program 1103 “Network-Based Cooperative Planning Processes in Structural Engineering” promoted by the German Research Foundation (DFG). Planning processes in civil engineering can be described by workflow graphs. The process structure describes the logical planning process and can be formally defined by a bipartite graph. This structure consists of activities, transitions and relationships between activities and transitions. In order to minimize errors at execution time of a planning process a consistent and structurally correct process model must be guaranteed. This contribution considers the concept and the algorithms for checking the consistency and the correctness of the process structure.
Diskrete Arbeitsvorgänge lassen sich mit Hilfe von Petri--Netzen formal beschreiben. Petri--Netze basieren auf der Graphentheorie. Die Elemente zweier Knotenmengen werden Stellen und Transitionen genannt und sind durch gerichtete Kanten miteinander verknüpft. Stellen repräsentieren Bedingungen oder Zustände und Transitionen Ereignisse oder Vorgänge. Durch Petri--Netze ist es möglich nicht nur eine statische Vorgänger--Nachfolger--Struktur abzubilden, vielmehr können ebenso Ereignisse, Alternativen und Nebenläufigkeiten modelliert werden. In diesem Beitrag wird vorgestellt, wie ein Bauablauf gegeben durch ein Vorgangsknoten-Netzplan mit sehr wenigen Schritten auf ein Bedingungs/Ereignis-Netz abgebildet werden kann. Alle notwenigen Teilschritte wie das Bilden von Teilnetzen oder das Vergröbern und Verfeinern von Knoten basieren auf einem mathematisch abgesicherten Fundament. Im Gegensatz zu anderen Formulierungen von Bauabläufen ist die Theorie der Petri-Netze eine allgemeingültige Theorie und kann in vielen Bereichen eingesetzt werden. Die Verwendung einer solchen mathematischen Abstraktion ermöglicht die Wiederverwendung von bereits entwickelten Lösungsansätzen. So können die gewonnenen Erfahrungen auch bei der Modellie-rung von anderen Arbeitsvorgängen verwendet werden.
Bei der Betrachtung von Stapelproblemen ergibt sich unter anderem folgendes Problem: Ein gegebener Stapel - bestehend aus den Elementen v i der Menge V - soll an anderer Stelle in einer vorgeschriebenen, veränderten Struktur wieder aufgebaut werden. Dazu stehen Hilfsstapelplätze zur Verfügung. Die Optimierung dieses Problems hinsichtlich der Anzahl der benötigten Hilfsstapelplätze ist NP-vollständig. Es werden Erfahrungen mit einem Branch-and-Bound Algorithmus zur Lösung des Problems vorgestellt sowie ein heuristischer Algorithmus diskutiert
With the help of functional analytical methods complex analysis is a powerful tool in treating non-linear first-order partial differential equations in the plane. Some of the most important of these equations are the Beltrami equations. This is due to the fact that the theory of Beltrami systems is related to many problems of geometry and analysis, like non-linear subsonic two-dimensional hydrodynamics, problems of conformal and quasiconformal mappings of two-dimensional Riemannian manifolds, or complex analytic dynamics. The theory of Beltrami equations is strongly connected with the -operator. This singular integral operator is immediately recognized as two-dimensional Hilbert-transform, known also under the name of integral operator with Beurling kernel, acting as an isometry of L2(C) onto L2(C). In hypercomplex function theory the Beltrami equations have not yet this importance, but nevertheless, they are a basic condition for the transfer of complex methods and efforts for solving partial differential equations, especially of non-linear type, to the spatial case. Here we deal with hypercomplex Beltrami systems. For this we restrict ourselves to the quaternionic case, but without any loss of generality. We will show how a spatial generalization of the complex -operator can be used to solve systems of non-linear partial differential equations, in particular different types of spatial Beltrami systems. Also, the for practical purposes so important norm estimates will be derived. Some of our results are stronger as known results in the complex case, but they are applicable in the complex situation, too.
In this paper, systematic analyses for the shoring systems installed to support the applied loads during construction are performed on the basis of the numerical approach. On the basis of a rigorous time-dependent analysis, structural behaviors of reinforced concrete (RC) frame structures according to the changes in design variables such as the types of shoring systems, shore stiffness and shore spacing are analyzed and discussed. The time-dependent deformations of concrete such as creep and shrinkage and construction sequences of frame structures are also taken into account to minimize the structural instability and to reach to an improved design of shoring system because these effects may increase the axial forces delivered to the shores. In advance, the influence of the column shortening effect, generally mentioned in a tall building structure, is analyzed. From many parametric studies, it has been finally concluded that the most effective shoring system in RC frame structures is 2S1R (two shores and one reshore) regardless of the changes in design variables.
This study aims at constructing the simulation system of distribution patterns of solar irradiance, sunshine duration and sky factor with the user-friendly interface and sharing this system with users on the Internet. The characteristics of this simulation system are as follows: (1) Web-based user interface, (2) Accessible system through the Internet and (3) Sunlight and skylight simulation based on physically accurate equations with considering various sky conditions and the reflection from the surface of objects. As a case study, impact of the development plans are analyzed and evaluated using this system. Solar irradiance, sunshine duration and sky factor are calculated at the surface of the buildings and open spaces every 10 minutes from 8 to 16 on the winter solstice. The values of these indices are expressed as the ratio to those calculated under the condition with no buildings. In conclusion, this web-based simulation system can be useful for visualizing the sunlight and skylight conditions on outdoor open spaces and the surface of the buildings to evaluate development plans objectively. Users can make access to the system from almost all of the computers connected with the Internet and modify parameters by themselves to get desirable results. Further improvement of the user interface is necessary using more advanced technology of CGI, Java and JavaScript.
Es wird gezeigt, daß im allgemeinen die Zeichnungsinhalte von Entwurfsplänen im konstruktiven Ingenieurbau in Teilzeichnungen zerlegt werden können, denen fachspezifische Objekte des Bauwesen entsprechen. Solche Objekte sind beispiels- weise Querschnitte, Träger, Stützen und Fundamente. Diese Teilobjekte werden durch eine unterschiedliche Anzahl von Parametern festgelegt werden. Wählt man für diese Parameter die entsprechendnen Fachbegriffe, so hat man durch diese die Möglichkeit die Teilobjekte auch in Datenbanken zu speichern. Neben den Sachparametern müssen auch zeichnungs- technische Werte, wie Maßstab, gewählte Längeneinheiten (m,cm..) und Einsatzpunkt - für die Lage des Teilobjektes im Gesamtplan - gespeichert werden. Zeichenmodule für jedes Teilobjekt können dann bei Aufruf eines bestimmten Planes aus den Daten der Datenbank die Teilzeichnungen generieren, sodaß eine Planspeicherung in der übliche Speicherform (Speicherelemente Punkt, Linie usw.) nicht mehr erforderlich ist. Neben der reinen Darstellung können die Programmodule auch dahingehend erweitert werden, daß auch die zugehörigen Berechnungen durchgeführt werden. Die numerischen Ergebnisse wie auch die Eingabewerte werden in einem alfanumerischen Dokument abgelegt. Damit ergibt sich dann ein Konstruktionsystem für den Entwurf, das insbesondere die Berechnung von Varianten sehr erleichertert. In Sonderfällen können auch die Pläne in ein Standard CAD Programm eingelesen werden, um allfällige Besonderheiten interaktiv zu ergänzen. Das relationale Modell wird weiters vorgestellt, nach dem die Zeichnungsinhalte gespeichert werden. Neben reinen Teilobjektsätzen werden auch Tabellensätze verwendet, um unter einem Namen mehrere numersiche Daten verwalten zu können. Es werden auch sogenannte Fort- setzungssätze besprochen, die in Entsprechung der stark unterschiedlichen Anzahl der Objektattibute verwendet werden.
Für den Entwurf der i.a. aus langen schmalen Rechtecken bestehenden Schal- bzw. Werkpläne wird eine Entwurfsunterstützung vorgestellt, bei der die Größe der Rechtecke wie immer festgelegt wird, die Lage der Rechtecke aber durch topologische Angaben. Letztere bilden programmtechnisch Bedingungen, wobei zwischen Berühr- und Bündigkeitsbedingen unterschieden wird. Diese Angaben positionieren das neue Rechteck im Bezug zu einem bereits platzierten. Zum Beispiel erlaubt die Angabe, die Säule ist oberhalb des Fundamentes und belastet dieses mittig, eine eindeutige Festlegung der Lage der Säule bei gegebener Lage des Fundamentes und gegebenen Abmessungen beider Rechtecke. Die Formulierung mittels Bedingungen hat den Vorteil daß diese auch bei Änderung von Abmessungen gültig bleiben. Die hier vorgestellte Eingabeart der relativen Positionierung ist eine Erweiterung des Orthomodus, wie er bei Bau-CAD-Programmen stets gefunden wird.
Seit mehreren Jahren wird im Fachbereich Gestaltung, Studiengang Innenarchitektur 3D-Computergrafik und -animation in Lehrveranstaltungen ausgebildet und in Projekt- und Diplomarbeiten als Darstellungsmedium angewandt. Eine besondere Herausforderung stellen dabei die 3D-Visualisierungen von historischen Gebäuden dar. Mit den beiden nachfolgenden Beispielen soll der Einsatz und die curricularen Verknüpfung der CA-Technologie mit Studienarbeiten und Projekten zum Thema >Denkmalpflege< aufgezeigt werden. Rekonstruktion und Visualisierung des ehemaligen >Jagdschlosses Platte< bei Wiesbaden. Mit Unterstützung einer Kunsthistorikerin wurde in einer Studienarbeit das im Krieg zerstörte ehemalige Jagdschloß im Computer nachgebildet. Neben der Darstellung des Gebäudeäußeren und des zentralen Innenbereiches wurde eine Animation über die Triangulierung der klassizistischen Geometrie erstellt. Umnutzung historischer Bausubstanz am Beispiel der ehemaligen Klostersanlage >Schiffenberg< bei Gießen. Im Rahmen einer Projektarbeit wurden mehrer Konzepte entwickelt, Entwürfe erstellt und mittels Computeranimationen öffentlich präsentiert. In Kooperation mit dem Studiengang Fernsehtechnik (FH-Wiesbaden) wurde von zwei Studenten eine Videodokumentation über den gesamten Projektverlauf erstellt. Neben dem Aufzeigen der Arbeitsprozesse und dem Vorstellen des Lehrkonzeptes für die curriculare Einbindung der CA-Technologie werden aktuelle Studienergebnisse anhand von Videoprojektionen vorgestellt.
We show a transformation K which allows us to rewrite the Dirac equation in its covariant form in a purely real quaternionic equation. We discuss how this transformation allows us for obtaining a involutive symmetry of the Dirac equation, as well as one simplification of the traditional vector of currents of the Dirac equation in traditional form. We also show the corresponding quaternionic equation for the problem of charge conjugation in the hole theory, and the quaternionic equation of conservation of currents. Finally, we discuss one decomposition of the quaternionic Dirac operator in two Maxwell's operators corresponding to time-harmonic case in homogeneous media, without sources which surprisingly agrees with the well known relation in quantum mechanics between the frequency ù and the impulse p E=p²c²+m²c, where E denotes the energy.
With the aid of factorization of the Schrödinger operator by quaternionic differential operators of first order proposed in recent works by S. Bernstein and K. Gürlebeck we study the system describing forcefree magnetic fields with nonconstant proportionality factor, the static Maxwell system for inhomogeneous media, the Beltrami condition and the Dirac equation with different types of potentials depending on one variable. We obtain integral representations for solutions of these systems.
In our project, we develop new tools for the conceptual design phase. During conceptual design, the coarse functionality and organization of a building is more important than a detailed worked out construction. We identify two roles, first the knowledge engineer who is responsible for knowledge definition and maintenance; second the architect who elaborates the conceptual design. The tool for the knowledge engineer is based on graph technology, it is specified using PROGRES and the UPGRADE framework. The tools for the architect are integrated to the industrial CAD tool ArchiCAD. Consistency between knowledge and conceptual design is ensured by the constraint checker, another extension to ArchiCAD.
Computational Steering provides methods for the integration of modeling, simulation, visualization, data analysis and post processing. The user has full control over a running simulation and the possibility to modify objects (geometry and other properties), boundary conditions and other parameters of the system interactively. The objective of such a system is to explore the effects of changes made immediately and thus to optimize the target problem interactively. We present a computational steering based system for fluid flow problems in civil engineering. It is based on three software components as shown in figure 1. The modeler is the CAD-system AutoCAD, which offers a powerful programming interface allowing an efficient access to the geometric data. It also offers convenient manipulators for geometric objects. The simulation kernel is a Lattice-Boltzmann (LB) solver for the Navier-Stokes equations, which is especially suitable for instationary flows in complex geometries. For the visualization and postprocessing we use the software tool AVS, which provides a powerful programming interface and allows the efficient visualization of flow fields. These three components are interconnected through two communication modules and three interfaces as depicted in figure 1. Interface 1 is responsible for the transformation of the modified system for the simulation kernel, interface 2 is responsible for the proper preparation of the simulation data whereas interface 3 transforms the data from the modeler into a format suitable for the visualization system. The whole system is synchronized by the two communication modules.
Review of Discrete Optimization Techniques for CAD Discrete optimization in the structure design Morphological method The alternative graph approach Convex discrete optimization without objective function Matroidal Decomposition in design Decomposition of layered matrices Discrete Optimization in Designing Packing problem Optimal arrangement of rectangles and shortest paths in L1-metrics Partition problems Discrete optimization in computational geometry and computer graphics Maxima of a point set on the plane Triangulation One of the main problems in computer graphics is removing hidden lines and surfaces
At present time neuronet's technologies have got a wide application in a different fields of technique. At the same time they give insufficient consideration to using neuron nets in the field of building. Use of approximating neuron nets will allow to definite the deflected mode of constructions elements using noticeably less computing facilities then by using universal methods, finite-element method for instance. Today neuron nets are used for calculation separate elements of building constructions. In this work use of neuron nets for calculation deflected mode of construction which consists of many elements is consider. The main idea of suggested analysis is using neuron nets for calculation internal intensities and transferences pieces of model which are selected by there functional destination. For example, a plate is destine for adoption intensity distributed among area, the purpose of core is taking up surface distributed intensity. Elements involved as intensity converter. Plate serve for intensities dispersion and their transfer. A template is associated with functional destination. A template regards as composition of model elements which has define functional destinations. A single template can incarnate several functional destinations. On receipt values of components transference the estimation of their permissibility is put into practice. In the case of detection a violation of permissible limit, in the component database is making a search for component with analogous functional destination, according to the type of violation. If such component is found than a change a previous component into new one is realized. Thus besides control a condition of construction by components there is a possibility to make a search for decisions of revealed problem....
Cost and Schedule Controlling in Relation to Liquidity Management during Construction Projects
(2004)
The present paper describes a software application which can be used for relating the scheduled events of a construction project with the respective financial parameters, leading to an overall improvement in general controlling and liquidity management. For this purpose, existing construction schedules are taken and details of the assignment are recorded. Thus it becomes possible to assess a future payment status should changes in the designated schedule occur.
The development of a consistent material model for textile reinforced concrete requires the formulation and calibration of several sub-models on different resolution scales. Each of these models represents the material structure at the corresponding scale. While the models at the micro-level are able to capture the fundamental failure and damage mechanisms of the material components (e.g. filament rupture and debonding from the matrix) their computational costs limit their application to the small size representative unit cells of the material structure. On the other hand, the macro-level models provide a sufficient performance at the expense of limited range of applicability. Due to the complex structuring of the textile reinforced concrete at several levels (filament - yarn - textile - matrix) it is a non-trivial task to develop a multiscale model from scratch. It is rather more effective to develop a set of conceptually related sub-models for each structural level covering the selected phenomena of the material behavior. The homogenized effective material properties obtained at the lower level may be verified and validated using experiments and models at the higher level(s). In this paper the development of a consistent material model for textile reinforced concrete is presented. Load carrying and failure mechanisms at the micro, meso and macro scales are described and models with the focus on the specified scales are introduced. The models currently being developed in the framework of the collaborative research center are classified and evaluated with respect to the failure mechanisms being captured. The micromechanical modeling of the yarn and bonding behavior is discussed in detail and the correspondence with the experiments focused on the selected failure and interaction mechanisms is shown. The example of modeling the bond layer demonstrates the application of the presented strategy.
This paper introduces the current development of electronic catalogues of construction products. The common system architecture of Web-based electronic products catalogues are discussed, followed by a discussion on construction products information standardization and latest distributed-systems technologies for communicating construction products information. Finally, this paper presents an implementation of Web service in e-commerce systems to enable sharing of construction products information.
Trotz der langjährigen Erfahrung bei der Anwendung objektorientierter Konzepte bei der Modellierung von Gebäuden ist es bisher nicht gelungen, ein allgemein anerkanntes Gebäudemodell im Rechner abzubilden. Das mag zum einen daran liegen, daß die Standardisierung eines solchen Modells bis heute zu keinem Abschluß gekommen ist. Zum anderen aber scheint vor allem die Problematik der Abbildung eines solchen Gebäudemodells in das Objektmodell einer Programmiersprache bisher unterschätzt worden zu sein. Die erhoffte Durchgängigkeit von objektorientierter Analyse, Entwurf und Programmierung gelingt bei Anwendungen für Entwurfsaufgaben nicht. Das gilt vor allem für Anwendungen, die frühe Entwurfsphasen unterstützen und damit erst zur Definition eines Gebäudemodells beitragen. Im Bereich der Softwareentwicklung wird das Konzept des Objektes als Ordnungsbegriff zur Strukturierung von Softwaremodulen benutzt. Die Übertragung dieser Ordnung in die Welt des Ingenieurs oder Architekten zur Bezeichnung eines konkreten Elements aus einem Modell (Raum 42 aus der Menge aller Räume des Gebäudes Blumenstraße 7) kann daher nur zu begrenzten Erfolgen führen. Aus der Analyse der Widersprüchlichkeit des Objektbegriffs zwischen Softwareentwickler (Programmierer) und Softwareanwender (Ingenieur, Architekt) wird im folgenden ein Laufzeitsystem für dynamische Objektstrukturen entwickelt, das es dem Softwareentwickler erlaubt, sowohl auf die Struktur als auch auf die Ausprägung eines Modells zuzugreifen. Dem Softwareanwender können damit Werkzeuge zur Verfügung gestellt werden, die es ihm gestatten, Gebäudemodelle zu definieren. Das Laufzeitsystem enthält zum einen eine Reihe von Klassen, die es ermöglichen, die Struktur von Anwenderobjekten dynamisch zu beschreiben und zu analysieren. Eine zweite Art von Klassen erlaubt das Erzeugen und Verändern von Anwenderobjekten, die diesen Strukturen entsprechen
Bauwerke werden heute mit umfassender Systematik Bauwerke werden heute mit umfassender Systematik die Brauchbarkeit der Bauwerke werden durch Normung und Prüfung intensiv beeinflußt. Der Computereinsatz ist in diesem Bereich allgemein üblich. Im Gegensatz zu Planungs- und Ausführungsphase eines Bauwerks ist die Betriebsphase wenig systematisiert. Dies ist überraschend, da die Betriebsphase über die Lebensdauer eines Bauwerks hinweg wesentlich größere Kosten verursacht, als der Rohbau und da der Nutzen des Bauwerks ja nicht in seiner Errichtung sondern in seinem Betrieb liegt. Die mangelnde Systematik der Bewirtschaftung ist beispielsweise daran ersichtlich, daß es im allgemeinen noch keine brauchbare Dokumentation der Gebäudebewirtschaftung, wenige Normen und wenig Software für diesen Aufgabenbereich gibt.
Development of Urban Land Use Model to Compare Transit-Oriented and Automobile-Oriented Cities
(2004)
This study is an attempt to develop a simple simulation model that can compare the differences between automobile-oriented and transit-oriented cities, and clarify the difference between city forms by transportation modes. Following a theoretical model development, a series of simulation runs are tried. The model allocates people who commute to CBD from residential zones along a transportation corridor. As a result of many simulation analyses, it is shown that automobiles need much more traffic space in comparison with the transit as is shown by the proposed traffic space ratio both in CBD and along the corridor.
In this Paper, we explored the relation between the electricity consumption in residential sector and the automobile energy consumption in transportation sector in accordance with the location of city by employing Geographic Information System (GIS). We found in the study that the electricity consumption per capita has a tendency that is higher in city center and lower in suburbs in Utsunomiya city. It is also noted that there is little difference among total consumption between city center and suburbs, despite the fact that the density of electric appliances tends to increase in a small size house of city center and the amount of automobile energy consumption from residence is lower in city center than in suburbs.
Building design, realization, operation and refurbishment have to take into account the environmental impacts as well as the resulting costs over a long period of time. LCA methods had to be developed for buildings because of their complexity, their long life duration and through a large number of actors who are involved. This was realized by integrating life cycle analysis, life cycle costing and building product models in integrated LCA models. However the use of such models leads to difficulties. The principal ones are the uncertainty treatment in LCA models and the lack of experience of practitioners who are not LCA specialists. Answers to these problems are the management of uncertainty and the development of simplified models for building design, construction and operation. This can be achieved with the mean of experimental plans or Monte Carlo simulation. The paper will focus on how these techniques can be used, what are their possibilities and disadvantages, particularly concerning the development of simplified models.
In the rpocess of project construction organization under conditions of limited resources the problem of investor arises, which in onecriteria setting is as follows N invsted projects reindexed i=1,2,...,n are considered, initial parameters of the problem are:- duraion of iproject construction, - expected profit per unit of time from i project after putting it info operation ,-the time fixed , after the expiry of it a fine is paid for each overdued unit of time units in number. The investor resources are limited, i.e., at every moment of time investor can provid delivering of necessary resources only for one project .Any admissible problem decision of investor represents one of n! permutation of of numbers 1,2,..,n. X={x}-is the set of all admissible solutions (SAS) of this problem . In works of different authors the quality of decision is evaluated either by objective function (OF) of the type MINSUM where,by the objective function of the of the type MINMAX
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...
In recent years, the survey is performed for repair, such as a bridge and a building built in past, spending great expense. And it is anxious for the survey technique that doesn’t need cost and time more. Then, we made an idea of the technique of precise 3D model creation by 2D pictures. However, the technique of performing the improvement in accuracy of convergent photographing and automatic acquisition of corresponding points was not established. Therefore, in this research, we try to obtain a semi-automation of corresponding points acquisition from initial corresponding points and the improvement in accuracy of convergent photographing. Moreover, we applied the research to the used house of Japanese real estate, and the applicable field was selected as the high needs of the residence of 3D model. And we developed the system that everyone could create Web / 3D model house by VRML easily without requiring expensive apparatuses or expertise.
The dynamic behaviour of shells, which are widely used in construction and mechanical engineering as critical components of machinery and 3-D structures, under static and dynamic loadings is described by system of deep nonlinear differential equations. Solution of these equations can be received with assistance of technique basing on a modern numerical algorithms and computer modeling.. The system of nonlinear differential equations of vibration of the shells is proposed taking into account the inertia forces in the tangential and normal directions. Its solution is based on combination of parameter prolongation method, finite-difference method and the Newton-Kantorovich iterative algorithm that allows plotting the loading trajectories and determination of bifurcation points on them. Package of Applied Programs >SEVSOR< is a computation means to be used in research of deformation, stability and vibration in thin axically-symmetric shells of complicated shape Input data include information on shell geometry, physical and mechanical properties, bearing conditions, types of loadings and load application. Frame output of motion forms in real time or either in decelerated or accelerated time scales for creating cartoons or video films is used for analysis of the compound dynamic processes in shell-type structures.
Das Eintreffen der Passagiere einer Haltestelle eines öffentlichen Nahverkehrsmittel wird als stochastischer Prozeß beschrieben . Die Ankünfte der Nahverkehrsmittel stellen einen Erneuerungsprozeß dar , wohingegen die Ankünfte der Personen innerhalb einer Erneuerungsperiode als instationärer Poissonprozeß aufgefaßt wird. Über die Intensitätsfunktion liegen Messungen vor. Betrachtet wird die Gesamt- wartezeit der Personen an einer Haltestelle .
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.
In [1] a quaternionic reformulation of the time-harmonic Maxwell equations for chiral media was proposed and used in [2] in order to construct complete systems of quaternionic fundamental solutions convenient for numerical analysis of scattering boundary value problems. In the present contribution we give a quaternionic reformulation of time-dependent Maxwell's equations for chiral media. The Maxwell system is written as a single quaternionic equation. We obtain a fundamental solution of this equation and use it for solving Maxwell's system with sources. This is a joint work with V. V. Kravchenko. [1] Khmelnytskaya, K. V., Kravchenko, V. V. and H. Oviedo: Quaternionic integral representations for electromagnetic fields in chiral media. Telecommunications and Radio Engineering 56 (2001), # 4&5, 53-61. [2]Khmelnytskaya, K. V. , Kravchenko, V. V. and V. S. Rabinovich: Quaternionic Fundamental Solutions for Electromagnetic Scattering Problems and Application. Zeitschrift für Analysis und ihre Anwendungen 22 (2003), 147--166.
Im Rahmen eines BMWT-geförderten Projekts entstand innerhalb einer Kooperation der Ritter Energie-und Umwelttechnik mit der Universität Karlsruhe (Fachbereich Bauphysik und Technischer Ausbau) eine bedarfsgeführte Fuzzy-Regelung für eine Lüftungsanlage mit Wärmerückgewinnung. Da bei Niedrigenergie-und Passivhäusern die Wärmeverluste über die Lüftung vergleichsweise hoch sind, besteht hier noch Einsparbedarf.Eine bedarfsgeführte Regelung kann die Lüftungsrate reduzieren, wenn z.B. mehrere Bewohner abwesend sind oder Fensterlüftung betrieben wird und die Luftqualität somit gut genug ist. Ausserdem wird die Lüftung reduziert, wenn die Raumluft in der Heizperiode zu trocken wird. Die sog. Fuzzy-Logik eignet sich gut für solche Regelungsaufgaben, bei denen menschliches Empfinden und Entscheiden nachgebildet werden soll. Fuzzy bedeutet eigentlich >unscharf<, d.h. es wird mit unscharfen Begriffen gearbeitet. Eine typische Anweisung in einer Fuzzy-Regelbasis lautet z.B. >Wenn die Luft trocken ist dann wenig lüften<. Der Prozess, in dem die Zugehörigkeit einer scharfen Messgröße zu den verschiedenen Fuzzy-Sets wie >trocken<, >mittel< und >feucht< bestimmt wird, heisst >Fuzzifizierung<. Das Anwenden der Regeln und das Extrahieren des unscharfen Ergebnisses heisst >Interferenz<. Abschließend wird eine >Defuzzifizierung< vorgenommen, um wieder ein scharfes Ergebnis zu erhalten. Die Fuzzy-Lüftungsregelung hat sich in Feldtests sehr gut bewährt. Simulationsrechnungen mit dem Gebäudesimulationsprogramm >ColSim< haben ausserdem gezeigt, dass im Passivhaus bis zu 16% der für Heizen und Lüften verbrauchten Primärenergie eingespart werden kann, wenn die Fuzzy-Regelung gegen eine konventionelle Drei-Stufen-Regelung auf Stufe >Normal< antritt. Gleichzeitig wird der Wohnkomfort deutlich erhöht, da Luftqualität und Feuchte stets im richtigten Bereich bleiben.
The management of resources is an essential task in each construction company. Today, ERP systems and e-Business systems are available to assist construction companies to efficiently organise the allocation of their personnel and equipment within the company, but they cannot provide the company with the idle resources for every single task that has to be performed during a construction project. Therefore, companies should have an alternative solution to better exploit expensive resources and compensate their fixed costs, but also have them available at the right time for their own business activities. This paper outlines the approach taken by the EU funded project “e-Sharing” (IST-2001-33325) to support resource management between construction companies. It will describe requirements for the management of construction resources, its core features, and the integration approach. Therefore, we will outline the approach of an integrated resource type model supporting the management and classification of construction equipment, construction tasks and qualification profiles. The development is based on a cross-domain analysis and evaluation of existing models. ...
Analysis System for Bridge Test (Chinese name abbr.: QLJC) is an application software specially designed for bridge test to analyze the static and dynamic character of bridge structures, calculate efficiency ratio of load test, pick up the results of observation points and so on. In this paper, research content, system design, calculation theory, characteristics and practical application of QLJC is introduced in detail.
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
In the given paper the generalized formulation of the problem of computer modelling of the complex-composite structure interaction with different types of dynamic loads and effects is discussed. Here the analysis is given as for the usage of some universal computing systems for the solution of such problems. Also if is shown that the quantification of the dynamic models of the complex-composite systems with the variable structure, depending on the character and intensivity of the effects, is necessary. The different variants of the joint and the space structure element modelling are gested. It allows to consider the complex modes of the joint bending-torsional oscillations of such structures as bridges, towers, high-rise buildings. The peculiarities of the modelling and testing of some problems of the objects aerodynamics and the interaction of the frameworks constructions with shock and movable loads are considered. In this paper the examples of the complex-composite structure dynamic analysis are shown. It is achieved by means of some special methods of the input of the real inducements and loads of the exploitated analog-object into the computing model. The suggested models found a wide use both at the design of new structures and the dynamic monitoring of the exploitated structures.
Some key facts about the economic environment of construction industry are explained. It is shown that construction industry is very heterogeneous and has changed drastically during the recent years due to a rapidly moving commercial environment. Two examples of todays’s use of virtual construction tools in construction projects are presented. The first example is the document control for a large international project. The second is the application of 4D modelling in the preconstruction phase of a dam project. It is shown that virtual construction, is a major international trend that currently takes up speed. Some generic industry needs for Research and Development which aims at short and medium term results are presented.
The paper presents the abstraction of process relevant information in order to enable the workflow management based on semantic data. It is shown for three examples, how the standards define the information needed to perform a certain planning activity. Abstraction of process relevant information is discussed for different granularities of the underlying processmodel. As one possible application ProMiSE is introduced, which uses process relevant data in individual tokens in a petri-net based process-model.
Der Beitrag basiert auf den Ansätzen und Ergebnissen des Forschungsprojekts >Prozessorientierte Vernetzung von Ingenieurplanungen am Beispiel der Geotechnik<, das im Rahmen des Schwerpunktprogramms 1103 >Vernetzt-kooperative Planungsprozesse im Konstruktiven Ingenieurbau< von der DFG gefördert wird. Ziel des gemeinsam mit dem Institut für Numerische Methoden und Informatik im Bauwesen an der TU Darmstadt durchgeführten Forschungsprojekts ist die Entwicklung einer netzwerkbasierten Kooperationsplattform zur Unterstützung von geotechnischen Ingenieurplanungen. Daher konzentriert sich das Forschungsprojekt auf die Abbildung und Koordination der Planungsprozesse für Projekte des Konstruktiven Ingenieurbaus vor dem Hintergrund der stark arbeitsteiligen Projektbearbeitung in einer verteilten Rechnerumgebung. Der Beitrag stellt die Abstraktion von Prozessmustern im Bauplanungsprozess als Basis für die dynamische Prozessmodellierung in einem Kooperationsmodell dar. Ziel ist es, durch die Identifikation der mit dem Entwurf und der Dimensionierung eines Bauteils verbundenen Planungs- und Abstimmungsprozesse einen bauteilbezogenen Katalog von Prozessmustern zu abstrahieren. Die einzelnen Prozessmuster werden in jedem Bauplanungsprozess dynamisch über geeignete Kopplungsmechanismen in das aktuelle Prozessmodell integriert, so dass die für den Bauplanungsprozess typischen Veränderungen der Konstruktion und der Zusammensetzung des Planungsteams im Prozessmodell berücksichtigt werden können. Dazu werden im Beitrag die bisherigen Ergebnisse der Analyse des Planungsprozesses eines großen innerstädtischen Bauvorhabens, das als Referenzobjekt dient, sowie typischer Planungsszenarien in der Geotechnik vorgestellt. Anschließend werden Grundlagen und methodische Ansätze zur Modellierung von Prozessen mit der Methode der farbigen Petri-Netze mit individuellen Marken vorgestellt. Anhand von Beispielen für bauteilorientierte Prozessmuster wird die Funktionalität der Prozessmuster in sich und im gegenseitigen Zusammenspiel erläutert
The contribution introduces an adaptable process model to meet the special requirements of the coordination of planning activities in AEC (Architecture, Engineering, Construction). The process model is based on the concept of Coloured Petri-Nets and uses metainformation to characterize process-relevant information and to enable process-control based on the actual results of the planning.
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.
A large-scale computer modeling and simulation method is presented for environmental flows in urban area. Several GIS and CAD data were used for the preparation of shape model and an automatic mesh generation method based on Delaunay method was developed. Parallel finite element method based on domain decomposition method was employed for the numerical simulation of natural phenomena. The present method was applied to the simulation of flood flow and wind flow in urban area. The present method is shown to be a useful planning and design tool for the natural disasters and the change of environments.
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.
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...
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)...
Most retaining walls and box culverts built for arterial road construction are simple, and the design process of these structures is often repetitive and labor-intensive because they are so similar in structural configuration. Although some integrated design automation systems developed for retaining walls and box culverts have expedited the design process of these structures, the process of collecting and distributing the resultant engineering documents has not been fully integrated with the computer applications. We have been developing a Web-based design automation system to manage the resultant documents as well as to speed up the repetitive design process. Manipulation of engineering drawings in the Web page is one of the critical functions needed for Web-based design automation. eXtensible Markup Language (XML) and XML-based vector graphics are expected to facilitate the representation of engineering drawings in the Web page. In this paper, we present how we used XML and Scalable Vector Graphics (SVG) to compose engineering drawings and represent them in the Web page. XML Data Island we designed to define drawing components turned out effective in manipulating the engineering drawings in the Web page.