@inproceedings{Hommel2000, author = {Hommel, Angela}, title = {The Theory of Difference Potentials in the Three-Dimensional Case}, doi = {10.25643/bauhaus-universitaet.595}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5956}, year = {2000}, abstract = {The method of difference potentials can be used to solve discrete elliptic boundary value problems, where all derivatives are approximated by finite differences. Considering the classical potential theory, an integral equation on the boundary will be investigated, which is solved approximately by the help of a quadrature formula. The advantage of the discrete method consists in the establishment of a linear equation system on the boundary, which can be immediately solved on the computer. The described method of difference potentials is based on the discrete Laplace equation in the three-dimensional case. In the first step the integral representation of the discrete fundamental solution is presented and the convergence behaviour with respect to the continuous fundamental solution is discussed. Because the method can be used to solve boundary value problems in interior as well as in exterior domains, it is necessary to explain some geometrical aspects in relation with the discrete domain and the double-layer boundary. A discrete analogue of the integral representation for functions in will be presented. The main result consists in splitting the difference potential on the boundary into a discrete single- and double-layer potential, respectively. The discrete potentials are used to establish and solve a linear equation system on the boundary. The actual form of this equation systems and the conditions for solvability are presented for Dirichlet and Neumann problems in interior as well as in exterior domains}, subject = {Randelemente-Methode}, language = {en} } @inproceedings{WardThorpePrice2004, author = {Ward, Michael and Thorpe, Tony and Price, Andrew}, title = {The Re-use of Site Data to Inform Business Processes}, doi = {10.25643/bauhaus-universitaet.130}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1308}, year = {2004}, abstract = {The increased implementation of site data capture technologies invariably results in an increase in data warehousing and database technologies to store captured data. However, restricted use of data beyond the initial application could potentially result in a loss of understanding of site processes. This could in turn lead to poor decision making at production, tactical and strategic levels. Concrete usage data have been collected from two piling processes. These data have been analysed and the results highlighted potential improvements that could be made to existing site management and estimating processes. A cost benefit analysis has been used to support decision making at the strategic level where the identified improvements require capital expenditure.}, subject = {Bauwerk}, language = {en} } @inproceedings{ReinhardtGarrettScherer2000, author = {Reinhardt, Jan and Garrett, James H. and Scherer, Raimar J.}, title = {The preliminary design of a wearable computer for supporting Construction Progress Monitoring}, doi = {10.25643/bauhaus-universitaet.590}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5901}, year = {2000}, abstract = {Progress monitoring has become more and more important as owners have increasingly demanded shorter times for the delivery of their projects. This trend is even more evident in high technology industries, such as the computer industry and the chemical industry. Fast changing markets, such as the computer industry, force companies to have to build new facilities quickly. To make a statement about construction progress, the status of a building has to be determined and monitored over a period of time. Depicting the construction progress in a diagram over time, statements can be made about the anticipated completion of the project and delays and problems in certain areas. Having this information, measures can be taken to efficiently >catch up< on the schedule of the project. New technologies, such as wearable computers, speech recognition, touch screens and wireless networks could help to move electronic data processing to the construction site. Progress monitoring could very much take advantage of this move, as several intermediate steps of processing progress data can be made unnecessary. The processing of progress data could be entirely done by computers, which means that data for supporting decisions can be made available at the moment the construction progress is measured. This paper describes a project, that investigates how these new technologies can be linked to create a system that enhances the efficiency of progress monitoring. During the project a first prototype of a progress monitoring system was developed that allows construction companies and site supervisors to measure construction progress on site using wearable computers that are speech controlled and connected to a central database via a wireless network.}, subject = {Bauablauf}, language = {en} } @article{MinchTrochanowski1997, author = {Minch, M. J. and Trochanowski, A.}, title = {The numerical Modelling and Analysis of RC cracked Structures}, doi = {10.25643/bauhaus-universitaet.527}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5278}, year = {1997}, abstract = {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.}, subject = {Tragwerk}, language = {en} } @article{TolokTolokGomenyuk1997, author = {Tolok, V. A. and Tolok, A. V. and Gomenyuk, S. I.}, title = {The instrumental System of Mechanics Problems Analysis of the deformed Solid Body}, doi = {10.25643/bauhaus-universitaet.536}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5361}, year = {1997}, abstract = {In the abstract proposed is the Instrumental System of mechanics problems analysis of the deformed solid body. It supplies the researcher with the possibility to describe the input data on the object under analyses and the problem scheme based upon the variational principles within one task. The particular feature of System is possibility to describe the information concerning the object of any geometrical shape and the computation sheme according to the program defined for purpose. The Methods allow to compute the tasks with indefinite functional and indefinite geometry of the object (or the set of objects). The System provides the possibility to compute the tasks with indefinite sheme based upon the Finite Element Method (FEM). The restrictions of the System usage are therefore determined by the restrictions of the FEM itself. It contrast to other known programms using FEM (ANSYS, LS-DYNA and etc) described system possesses more universality in defining input data and choosing computational scheme. Builtin is an original Subsytem of Numerical Result Analuses. It possesses the possibility to visualise all numerical results, build the epures of the unknown variables, etc. The Subsystem is approved while solving two- and three-dimensional problems of Elasticiti and Plasticity, under the conditions of Geometrical Unlinearity. Discused are Contact Problems of Statics and Dynamics.}, subject = {Festk{\"o}rpermechanik}, language = {en} } @inproceedings{BrackxDeSchepperSommen2003, author = {Brackx, Fred and De Schepper, Nele and Sommen, Frank}, title = {The Hermite Transformation in Quaternionic Analysis}, doi = {10.25643/bauhaus-universitaet.281}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2817}, year = {2003}, abstract = {The conventional way of describing an image is in terms of its canonical pixel-based representation. Other image description techniques are based on image transformations. Such an image transformation converts a canonical image representation into a representation in which specific properties of an image are described more explicitly. In most transformations, images are locally approximated within a window by a linear combination of a number of a priori selected patterns. The coefficients of such a decomposition then provide the desired image representation. The Hermite transform is an image transformation technique introduced by Martens. It uses overlapping Gaussian windows and projects images locally onto a basis of orthogonal polynomials. As the analysis filters needed for the Hermite transform are derivatives of Gaussians, Hermite analysis is in close agreement with the information analysis carried out by the human visual system. In this paper we construct a new higher dimensional Hermite transform within the framework of Quaternionic Analysis. The building blocks for this construction are the Clifford-Hermite polynomials rewritten in terms of Quaternionic analysis. Furthermore, we compare this newly introduced Hermite transform with the Quaternionic-Hermite Continuous Wavelet transform. The Continuous Wavelet transform is a signal analysis technique suitable for non-stationary, inhomogeneous signals for which Fourier analysis is inadequate. Finally the developed three dimensional filter functions of the Quaternionic-Hermite transform are tested with traditional scalar benchmark signals upon their selectivity at detecting pointwise singularities.}, subject = {Quaternion}, language = {en} } @article{KazakevitchVolkova1997, author = {Kazakevitch, M. I. and Volkova, Viktorija}, title = {The exact Solution of the free pre-stressed Bar-Oscillations}, doi = {10.25643/bauhaus-universitaet.535}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5356}, year = {1997}, abstract = {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}, subject = {Bauteil}, language = {en} } @article{StrukeljSkrinar1997, author = {Strukelj, A. and Skrinar, Matjaz}, title = {The Evaluation of the Dynamical Soil-Bridge Interaction}, doi = {10.25643/bauhaus-universitaet.539}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5397}, year = {1997}, abstract = {In the design of a structure, the implementation of reliable soil-foundation-structure interaction into the analysis process plays a very important role. The paper presents a determination of parameters of a suitably chosen soil-foundation model and their influence on the structure response. Since the mechanical data for the structure can be determined with satisfactory accuracy, the properties of the soil-foundation model were identified using measured dynamic response of the real structure. A simple model describing soil-foundation structure was incorporated into the classical 3-D finite element analysis of the structure with commercial software. Results obtained from the measured data on the pier were afterwards compared with those obtained with the finite model of the pier-foundation-soil structure. On the basis of this comparison the coefficients describing the properties in the soil-foundation model were adjusted until the calculated dynamic response coincided with the measured ones. In this way, the difference between both results was reduced to 1\%. Full-scale tests measuring eigenmotion of the bridge were performed through all erection stages of the new bridge in Maribor. In this way an effective and experimentally verified 3-D model for a complex dynamic analysis of the bridge under the earthquake loading was obtained. The significant advantage of the obtained model is that it was updated on the basis of the dynamic measurements thus improving the model on the basis of in-situ geomechanical measurements. The model is very accurate in describing the upper structure and economical in describing the soil mass thus representing an optimal solution regarding computational efforts.}, subject = {Boden-Bauwerk-Wechselwirkung}, language = {en} } @article{KazakevitchKulyabkoDubichvost1997, author = {Kazakevitch, M. I. and Kulyabko, V. V. and Dubichvost, A. A.}, title = {The discrete dynamic Models of the Interaction of complex - composite Structures with the dynamic Loads}, doi = {10.25643/bauhaus-universitaet.521}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5219}, year = {1997}, abstract = {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.}, subject = {Verbundtragwerk}, language = {en} } @inproceedings{PetzoldDonath2004, author = {Petzold, Frank and Donath, Dirk}, title = {The building as a container of information : the starting point for project development and design formulation}, doi = {10.25643/bauhaus-universitaet.184}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1848}, year = {2004}, abstract = {For planning in existing built contexts, the building survey is the starting point for initial planning proposals, for the diagnosis and documentation of building damages, for the creation of objectives catalogues, for the detailed design of renovation and conversion measures and for ensuring fulfilment of building legislation, particularly by change of use and refitting. An examination of currently available IT-tools shows insufficient support for planning within existing contexts, most notably a deficit with regard to information capture and administration. This paper discusses the concept for a modular surveying system (basic concept, separation of geometry from semantic data, and separation into sub-systems) and the prototypical realisation of a system for the complete support of the entire building surveying process for existing buildings. The project aims to contribute to the development of a planning system for existing buildings. ...}, subject = {Architektur}, language = {en} } @article{Volkova2004, author = {Volkova, Viktorija}, title = {The analysis of dynamic behaviour of pre-stressed systems under polyharmonic excitations}, doi = {10.25643/bauhaus-universitaet.265}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2656}, year = {2004}, abstract = {Pre-stressed structural elements are widely used in large-span structures. As a rule, they have higher stiffness characteristics. Pre-stressed rods can be applied as girders of different purpose, and as their separate parts, e.g. rods of trusses and frames. Among numerous ways of prestressing the compression of girders, trusses, and frames by tightenings from high-strength materials is under common application.}, subject = {Verkehrsplanung}, language = {en} } @inproceedings{KonradChudobaButenweg2003, author = {Konrad, Martin and Chudoba, Rostislav and Butenweg, Christoph}, title = {Textile Reinforced Concrete Part II: Multi-Level Modeling Concept}, doi = {10.25643/bauhaus-universitaet.323}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3230}, year = {2003}, abstract = {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.}, subject = {Beton}, language = {en} } @inproceedings{ChudobaButenwegPfeiffer2003, author = {Chudoba, Rostislav and Butenweg, Christoph and Pfeiffer, Frank}, title = {Textile Reinforced Concrete Part I: Process Model for Collaborative Research and Development}, doi = {10.25643/bauhaus-universitaet.286}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2866}, year = {2003}, abstract = {The goal of the collaborative research center (SFB 532) >Textile reinforced concrete (TRC): the basis for the development of a new material technology< installed in 1998 at the Aachen University is a complex assessment of mechanical, chemical, economical and productional aspects in an interdisciplinary environment. The research project involves 10 institutes performing parallel research in 17 projects. The coordination of such a research process requires effective software support for information sharing in form of data exchange, data analysis and data archival. Furthermore, the processes of experiment planning and design, modification of material compositions and design parameters and development of new material models in such an environment call for systematic coordination applying the concepts of operational research. Flexible organization of the data coming from several sources is a crucial premise for a transparent accumulation of knowledge and, thus, for a successful research in a long run. The technical information system (TRC-TIS) developed in the SFB 532 has been implemented as a database-powered web server with a transparent definition of the product and process model. It serves as an intranet server with access domains devoted to the involved research groups. At the same time, it allows the presentation of selected results just by granting a data object an access from the public area of the server via internet.}, subject = {Beton}, language = {en} } @inproceedings{HauschildHuebler2003, author = {Hauschild, Thomas and H{\"u}bler, Reinhard}, title = {Techniken der Verwaltung dynamischer digitaler Bauwerksmodelle f{\"u}r Revitalisierungsvorhaben}, doi = {10.25643/bauhaus-universitaet.305}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3054}, year = {2003}, abstract = {Modellverwaltungssysteme sind eine geeignete technologische Basis zum Management digitaler Bauwerksmodelle bei Planungst{\"a}tigkeiten f{\"u}r den Neubau als auch f{\"u}r die Revitalisierung von Bauwerken. Die Unterst{\"u}tzung von Revitalisierungsprozessen impliziert f{\"u}r den Entwurf integrierter Planungsumgebungen spezifische Anforderungen wie die Repr{\"a}sentation von Informationen, die mit verschiedenen Typen von Vagheit behaftet sind, die Notwendigkeit, den Soll- sowie den Ist- Zustand des Bauwerks abzubilden und die F{\"a}higkeit des Umgangs mit temporal inkonsistenten Modellzust{\"a}nden. Die erforderliche Dynamik der Dom{\"a}nenmodelle und die erforderliche Nutzbarkeit in Virtual Enterprises stellen weitere Anspr{\"u}che an die Realisierungsbasis der Modellverwaltungssysteme. Zur Implementierung derartiger Systeme erweist es sich als vorteilhaft, Eigenschaften objektorientierter Programmiersprachen mit nichtstatischen Typsystemen auszunutzen, da diese durch die vorhandene Metaebene sowie Introspektions- und Reflektionsmechanismen eine effiziente Realisierungsbasis bereitstellen. Zur effektiven Unterst{\"u}tzung synchroner kooperativer Planungst{\"a}tigkeiten innerhalb einzelner Fachdisziplinen wurde ein Benachrichtigungsmechanismus realisiert, der an das Modellverwaltungssystem angekoppelte Fachapplikationen {\"u}ber nebenl{\"a}ufig vorgenommene Modifikationen am zugeh{\"o}rigen Dom{\"a}nenmodell oder an Projektinformationen informiert. Weiterhin existiert ein Mechanismus zur vereinfachten Anbindung von existierenden Applikationen, die auf statischen Partialmodellen beruhen oder standardisierte, modellbasierte Austauschformate unterst{\"u}tzen. Abschließend wird eine aus einem zentralen Projektserver, Dom{\"a}nenservern und Dom{\"a}nenclients bestehende hybride Systemarchitektur vorgestellt, die geeignet ist, unter den Randbedingungen kooperativer und geographisch verteilter Arbeit bei Revitalisierungsvorhaben in Virtual Enterprises eingesetzt zu werden.}, subject = {Bauwerk}, language = {de} } @phdthesis{Beer2005, author = {Beer, Daniel G.}, title = {Systementwurf f{\"u}r verteilte Applikationen und Modelle im Bauplanungsprozess}, doi = {10.25643/bauhaus-universitaet.750}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20060418-7892}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2005}, abstract = {Der Planungsprozess im Konstruktiven Ingenieurbau ist gekennzeichnet durch drei sich zyklisch wiederholende Phasen: die Phase der Aufgabenverteilung, die Phase der parallelen Bearbeitung mit entsprechenden Abstimmungen und die Phase der Zusammenf{\"u}hrung der Ergebnisse. Die verf{\"u}gbare Planungssoftware unterst{\"u}tzt {\"u}berwiegend nur die Bearbeitung in der zweiten Phase und den Austausch der Datenbest{\"a}nde durch Dokumente. Gegenstand der Arbeit ist die Entwicklung einer Systemarchitektur, die in ihrem Grundsatz alle Phasen der verteilten Bearbeitung und unterschiedliche Arten der Kooperation (asynchron, parallel, wechselseitig) ber{\"u}cksichtigt und bestehende Anwendungen integriert. Das gemeinsame Arbeitsmaterial der Beteiligten wird nicht als Dokumentmenge, sondern als Menge von Objekt- und Elementversionen und deren Beziehungen abstrahiert. Elemente erweitern Objekte um applikationsunabh{\"a}ngige Eigenschaften (Features). F{\"u}r die Bearbeitung einer Aufgabe werden Teilmengen auf Basis der Features gebildet, f{\"u}r deren Elemente neue Versionen abgeleitet und in einen privaten Arbeitsbereich geladen werden. Die Bearbeitung wird auf Operationen zur{\"u}ckgef{\"u}hrt, mit denen das gemeinsame Arbeitsmaterial konsistent zu halten ist. Die Systemarchitektur wird formal mit Mitteln der Mathematik beschrieben, verf{\"u}gbare Technologie beschrieben und deren Einsatz in einem Umsetzungskonzept dargestellt. Das Umsetzungskonzept wird pilothaft implementiert. Dies erfolgt in der Umgebung des Internet in der Sprache Java unter Verwendung eines Versionsverwaltungswerkzeuges und relationalen Datenbanken.}, subject = {Planungsprozess}, language = {de} } @inproceedings{AmezianeLasserre2003, author = {Ameziane, Farid and Lasserre, Stephane}, title = {SYSBAT - An Application to the Building ProductionBased on Computer Supported Cooperative Work}, doi = {10.25643/bauhaus-universitaet.274}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2748}, year = {2003}, abstract = {Our proposed solution is to enable partners of a construction project to share all the technical data produced and handled during the building production process by building a system through the use of internet technology. The system links distributed databases and allows building partners to access remotely and manipulate specific information. It provides an updated building representation that is being enriched and refined all along the building production process. A recent collaboration with Nemetschek France (subsidiary company of Nemetschek AG, AEC CAD software leader) focus on a building product repository available in a web context. The aim is to help building project actors to choose a technical solution that fits its professional needs, and maintain our information system with up to date information. It starts with the possibility to build on line building product catalogs, in order to link Allplan CAD entities with building technical features. This paper presents the conceptual approaches on which our information system is built. Starting from a general organization diagram organization, we focus on the product and the description branches of construction works (including last IFC model specifications). Our aim is to add decisional support to the construction works selection process. To do so, we consider the actor's role upon the system and the pieces of information each one needs to achieve a given task.}, subject = {Bauplanung}, language = {en} } @inproceedings{Vasilkov2003, author = {Vasilkov, Dmitry M.}, title = {Surface design based upon a combined mesh}, doi = {10.25643/bauhaus-universitaet.367}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3671}, year = {2003}, abstract = {The subject of this talk is the problem of surface design based upon a mesh that may contain both triangular and quadrangular domains. We investigate the cases when such a combined mesh occurs more preferable for bivariate data interpolation than a pure triangulation. First we describe a modification of the well-known flipping algorithm that constructs a locally optimal combined mesh with a predefined quality criterion. Then we introduce two quality measures for triangular and quadrangular domains and present the results of a computational experiment that compares integral interpolation errors and errors in gradients caused by the piecewise surface models produced by the flipping algorithm with the introduced quality measures. The experiment shows that triangular meshes with the Delaunay quality measure provide better interpolation accuracy only if the interpolated function is strictly convex, as well as a saddle-shaped function is better interpolated by bilinear patches within a combined mesh. For a randomly shaped function combined meshes demonstrate smaller error values and better stability in compare with pure triangulations. At the end we consider other resources for mesh improvement, such as excluding >bad< points from the input set for the mesh generating procedure. Because the function values at these points should not be lost, some linear or bilinear patches are replaced by nonlinear patches that pass through the excluded points.}, subject = {Oberfl{\"a}che}, language = {en} } @inproceedings{BuergyGarrett2004, author = {B{\"u}rgy, Christian and Garrett, James H.}, title = {Supporting Domain Experts in Determining Viable User Interface Designs for Wearable Computers Used in AEC Work Situations}, doi = {10.25643/bauhaus-universitaet.116}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1168}, year = {2004}, abstract = {The design of mobile IT systems, especially the design of wearable computer systems, is a complex task that requires computer science knowledge, such as that related to hardware configuration and software development, in addition to knowledge of the domain in which the system is intended to be used. Particularly in the AEC sector, it is necessary that the support from mobile information technology fit the work situation at hand. Ideally, the domain expert alone can adjust the wearable computer system to achieve this fit without having to consult IT experts. In this paper, we describe a model that helps in transferring existing design knowledge from non-AEC domains to new projects in the construction area. The base for this is a model and a methodology that describes the usage scenarios of said computer systems in an application-neutral and domain-independent way. Thus, the actual design information and experience will be transferable between different applications and domains.}, subject = {Mobile Computing}, language = {en} } @inproceedings{AldaCremersBilek2004, author = {Alda, Sascha and Cremers, Armin B. and Bilek, Jochen}, title = {Support of Collaborative Structural Design Processes through the Integration of Peer-to-Peer and Multiagent Architectures}, doi = {10.25643/bauhaus-universitaet.148}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1481}, year = {2004}, abstract = {Structural engineering projects are increasingly organized in networked cooperations due to a permanently enlarged competition pressure and a high degree of complexity while performing the concurrent design activities. Software that intends to support such collaborative structural design processes implicates enormous requirements. In the course of our common research work, we analyzed the pros and cons of the application of both the peer-to-peer (University of Bonn) and multiagent architecture style (University of Bochum) within the field of collaborative structural design. In this paper, we join the benefits of both architecture styles in an integrated conceptual approach. We demonstrate the surplus value of the integrated multiagent-peer-to-peer approach by means of an example scenario in which several structural engineers are co-operatively designing the basic structural elements of an arched bridge, applying heterogeneous CAD systems.}, subject = {Ingenieurbau}, language = {en} } @inproceedings{Abramian1997, author = {Abramian, A. K.}, title = {Superelliptic Shells as new constructive Forms}, doi = {10.25643/bauhaus-universitaet.434}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4347}, year = {1997}, abstract = {In the superelliptic shell joined to a circular cylinder bending stresses are absent when it is subjected to uniform pressure.Some geometrical characteristics have been found. Expressions for determining stresses in the shell crest(in the singular point of plane type) are suggested. The problem of a theoretical critical buckling load of an elongated shell supported by frames is studied. A critical buckling load for two shells with different specifications was found experimentally.}, subject = {Schale}, language = {en} } @article{KeJianMing2004, author = {Ke, Chen and Jian Ming, Lu}, title = {Study of Analysis System for Bridge Test}, doi = {10.25643/bauhaus-universitaet.254}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2547}, year = {2004}, abstract = {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.}, subject = {Finite-Elemente-Methode}, language = {en} } @phdthesis{Coulon1997, author = {Coulon, Carl-Helmut}, title = {Strukurorientiertes Fallbasiertes Schließen}, doi = {10.25643/bauhaus-universitaet.24}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20040212-265}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {1997}, abstract = {Das Ziel dieser Arbeit war es, durch Verwendung geeigneter vorhandener CAD-Pl{\"a}ne die Bearbeitung neuer CAD-Pl{\"a}ne zu unterst{\"u}tzen. Entstanden ist ein generischer Ansatz zum fallbasierten Schließens. Da in CAD-Pl{\"a}nen die r{\"a}umliche Struktur eine wichtige Rolle spielt, ist das Konzept auf strukturorientierte Anwendungen ausgerichtet. Deshalb bezeichne ich es als ein Konzept zum " strukturorientierten fallbasierten Schließen". Die Arbeit spezifiziert das Minimum an Wissen, welches zur Suche und Wiederverwendung von F{\"a}llen ben{\"o}tigt wird, wie das dar{\"u}ber hinausgehende Wissen verarbeitet wird, welche Zusammenh{\"a}nge es zum Beispiel zwischen Vergleichs- und Anpassungswissen gibt und wie man das Wissen modellieren kann. Zur Erl{\"a}uterung wird das ben{\"o}tigte Wissen anhand verschiedener Anwendungen dargestellt. Das in der Arbeit vorgestellte Konzept erlaubt die Erg{\"a}nzung, Detaillierung und Korrektur einer Anfrage. Die beiden entscheidenden Algorithmen dienen dem Vergleich von Anfrage und Fall und der Anpassung der Information des Falles zur Modifikation der Anfrage.}, subject = {Fallbasiertes Schließen}, language = {de} } @inproceedings{XieIssaO'Brien2004, author = {Xie, Haiyan and Issa, Raja and O'Brien, William}, title = {Structure of a Formal User Model for Construction Information Retrieval}, doi = {10.25643/bauhaus-universitaet.129}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1296}, year = {2004}, abstract = {Information science researchers and developers have spent many years addressing the problem of retrieving the exact information needed and using it for analysis purposes. In informationseeking dialogues, the user, i.e. construction project manager or supplier, often asks questions about specific aspects of the tasks they want to perform. But most of the time it is difficult for the software systems to unambiguously understand their overall intentions. The existence of information tunnels (Tannenbaum 2002) aggravates this phenomenon. This study includes a detailed case study of the material management process in the construction industry. Based on this case study, the structure of a formal user model for information retrieval in construction management is proposed. This prototype user model will be incorporated into the system design for construction information management and retrieval. This information retrieval system is a user-centered product based on the development of a user configurable visitor mechanism for managing and retrieving project information without worrying too much about the underlying data structure of the database system. An executable UML model combined with OODB is used to reduce the ambiguity in the user's intentions and to achieve user satisfaction.}, subject = {Bauwerk}, language = {en} } @inproceedings{KoenigKlingerBerkhahn2004, author = {K{\"o}nig, Markus and Klinger, Axel and Berkhahn, Volker}, title = {Structural Correctness of Planning Processes in Building Engineering}, doi = {10.25643/bauhaus-universitaet.169}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1690}, year = {2004}, abstract = {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.}, subject = {Baubetrieb}, language = {de} } @inproceedings{PerevalovaPahl2004, author = {Perevalova, Julia and Pahl, Peter Jan}, title = {Structural and Functional Dependence of Objects in Data Bases}, doi = {10.25643/bauhaus-universitaet.168}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1683}, year = {2004}, abstract = {Let the information of a civil engineering application be decomposed into objects of a given set of classes. Then the set of objects forms the data base of the application. The objects contain attributes and methods. Properties of the objects are stored in the attributes. Algorithms which the objects perform are implemented in the methods of the objects. If objects are modified by a user, the consistency of data in the base is destroyed. The data base must be modified in an update to restore its consistency. The sequence of the update operations is not arbitrary, but is governed by dependence between the objects. The situation can be described mathematically with graph theory. The available algorithms for the determination of the update sequence are not suitable when the data base is large. A new update algorithm for large data bases has been developed and is presented in this paper.}, subject = {Baubetrieb}, language = {en} } @article{Fink2004, author = {Fink, Thomas}, title = {Structural analysis, design and detailing using standard CAD software and standard building information model}, doi = {10.25643/bauhaus-universitaet.270}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2702}, year = {2004}, abstract = {This paper describes the concept of a german commercial software package developed for the needs of structural engineers. Using a standard CAD software as user interface for all geometrical data and to save all important input data, there is a natural link to upcoming building information models.}, subject = {Bauindustrie}, language = {en} } @article{RombergNigglvanTreeck2004, author = {Romberg, Richard and Niggl, Andreas and van Treeck, Christoph}, title = {Structural Analysis based on the Product Model Standard IFC}, doi = {10.25643/bauhaus-universitaet.243}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2433}, year = {2004}, abstract = {In this paper we present a computer aided method supporting co-operation between different project partners, such as architects and engineers, on the basis of strictly three-dimensional models. The center of our software architecture is a product model, described by the Industry Foundation Classes (IFC) of the International Alliance for Interoperability (IAI). From this a geometrical model is extracted and automatically transferred to a computational model serving as a basis for various simulation tasks. In this paper the focus is set on the advantage of the fully three-dimensional structural analysis performed by p-version of the finite element analysis. Other simulation methods are discussed in a separate contribution of this Volume (Treeck 2004). The validity of this approach will be shown in a complex example.}, subject = {Produktmodell}, language = {en} } @article{GirlichKovalevZaporozhets1997, author = {Girlich, E. and Kovalev, M. and Zaporozhets, A.}, title = {Standardization problem: Ressource Allocation in a Network}, doi = {10.25643/bauhaus-universitaet.517}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5172}, year = {1997}, abstract = {We consider the standardization problem (SP) which can be formulated as follows. It is known demand bi in each type i in {1, 2, ..., n} of items. Production of yi items of the ith type brings a profit fi (yi), where fi is a nondecreasing concave function for each i in {1, 2, ..., n}.It is necessary to satisfy the demand and to maximize the total profit provided that there exist >standardization possibilities< . These possibilities means that some types of items can be replaced by some another types. We introduce generalized standardization problem (GSP) in which titems demand is given as the set of admissible demand vectors. We show that GSP and SP are special cases of the resource allocation problem over a network polymatroid. Ibasing on this observation we propose a polynomial time solution algorithm for GSP and SP.}, subject = {Ressourcenallokation}, language = {en} } @article{SchneiderBeucke1997, author = {Schneider, Ulrich and Beucke, Karl}, title = {Standardisierung der Kommunikation als Integrationsansatz f{\"u}r das Bauwesen}, doi = {10.25643/bauhaus-universitaet.548}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5483}, year = {1997}, abstract = {Eine der wichtigsten Aufgaben und Herausforderungen der Bauinformatik ist gegenw{\"a}rtig die Realisierung des durchg{\"a}ngigen, fach{\"u}bergreifenden Datenflusses im Planungsprozeß eines Bauvorhabens. Im Hinblick auf die internationale Wettbewerbsf{\"a}higkeit der deutschen Bauwirtschaft ist es unumg{\"a}nglich, vorhandene Effizienzpotentiale in der Bauplanung auszusch{\"o}pfen, welche durch eine qualitative Verbesserung der Planung sowie durch eine Verringerung der Bearbeitungszeit aller beteiligten Fachplanern erreicht werden k{\"o}nnen. Nach dem gegenw{\"a}rtigen Stand der Technik werden die Informationsobjekte standardisiert, damit sie durchg{\"a}ngig nutzbar sind. Diese werden in einem allgemeing{\"u}ltigen Format den speziellen Programmen der Fachplaner zur Verf{\"u}gung gestellt. In dieser Arbeit wird der Ansatz verfolgt, eine Integration durch die Standardisierung der Kommunikation zwischen den Informationsobjekten und ihren Anwendungsprogrammen zu erreichen. Dabei kann auf die Standardisierung der zu {\"u}bertragenden Objekte verzichtet werden. Ziel der Ausarbeitung ist die Definition von implementationstechnischen Regeln, die alle auszutauschenden Objekte sowie die Anwendungen, die solche Objekte aufnehmen wollen, erf{\"u}llen m{\"u}ssen. Die Bearbeitung der Objekte soll in den gewohnten Anwendungen in unver{\"a}nderter Weise erfolgen.}, subject = {Bauwesen}, language = {de} } @phdthesis{Schneider2000, author = {Schneider, Ulrich}, title = {Standardisierung der Kommunikation als Integrationsansatz f{\"u}r das Bauwesen}, doi = {10.25643/bauhaus-universitaet.72}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20040311-751}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2000}, abstract = {In dieser Arbeit wird eine neue Methode f{\"u}r die Integration von Informationen in digitalen Planungsunterlagen erarbeitet. Die Grundidee des Integrationsansatzes st{\"u}tzt sich auf die aktive Einbeziehung der Anwender w{\"a}hrend der Realisierung der {\"U}bernahme von Informationen und bei der Aktualisierung von Planungsunterlagen, die inkonsistent zu anderen Planungsunterlagen sind. Diese Grundidee kombiniert mit den M{\"o}glichkeiten neuer Kommunikationstechnologien war f{\"u}r die Spezifikation von neuen Methoden f{\"u}r die {\"U}bernahme von Informationen und f{\"u}r die {\"U}berwachung von Ver{\"a}nderungen ausschlaggebend. Die neuen Methoden werden in dieser Ausarbeitung erarbeitet und vorgestellt. Ziel der Ausarbeitung ist die Definition von implementationstechnischen Regeln, die alle auszutauschenden Objekte erf{\"u}llen m{\"u}ssen. Die Realisierung der Integrationsaufgaben durch den Anwender basiert dabei auf den M{\"o}glichkeiten der traditionellen Integration analoger Dokumente.}, subject = {Bauwesen}, language = {de} } @inproceedings{Sotskov2003, author = {Sotskov, Yuri N.}, title = {Stability of an optimal schedule for a flow-shop problem with two jobs}, doi = {10.25643/bauhaus-universitaet.369}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3690}, year = {2003}, abstract = {The problem F|n=2|F is to minimize the given objective function F(C1,m, C2,m) of completion times Ci,m of two jobs i {\^I} J={1, 2} processed on m machines M={1, 2, …, m}. Both jobs have the same technological route through m machines. Processing time ti,k of job i{\^I} J on machine k{\^I} M is known. Operation preemptions are not allowed. Let R2m be space of non-negative 2m-dimensional real vectors t=(t1,1,…, t1,m, t2,1,…, t2,m) with Chebyshev's distance d(t, t*). To solve problem F|n=2|F, we can use the geometric algorithm, which includes the following steps: 1) construct digraph (V, A) for problem F|n=2|F and find so-called border vertices in (V, A); 2) construct the set of trajectories corresponding to the shortest paths Rt in digraph (V, A) from the origin vertex to each of the border vertices; 3) find an optimal path in the set Rt that represents a schedule with minimal value of the objective function F. Let path tu {\^I} Rt be optimal for the problem F|n=2|F with operation processing times defined by vector t. If for any small positive real number e > 0 there exists vector t*{\^I} R2m such that d(t, t*) = e and path tu is not optimal for the problem F|n=2|F with operation processing times defined by vector t*, then optimality of path tu is not stable. The main result of the paper is the proof of necessary and sufficient conditions for optimality stability of path tu. If objective function F is continuous non-decreasing (e.g., makespan, total completion time, maximal lateness or total tardiness), then to test whether optimality of the path tu {\^I} Rt is stable takes O(m log m) time.}, subject = {Ablaufplanung}, language = {en} } @inproceedings{Milbradt2003, author = {Milbradt, Peter}, title = {Stabilisierte Finite Elemente in der Hydrodynamik}, doi = {10.25643/bauhaus-universitaet.332}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3327}, year = {2003}, abstract = {Hydro- und morphodynamischen Prozesse in Binnengew{\"a}ssern und im K{\"u}stennahbereich erzeugen hochkomplexe Ph{\"a}nomene. Zur Beurteilung der Entwicklung von K{\"u}stenzohnen, 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-, Str{\"o}mungs- 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 f{\"u}r vektorwertige mehrdimensionale Probleme, bei dem der Fehler eines Standard-Galerkin-Verfahrens mit Hilfe eines Upwinding-Koeffizienten minimiert wird. Die Wahl des Upwinding-Koeffizienten ist {\"u}bertragbar auf andere Problemklassen und basiert ausschließlich auf dem Charakter der zugrundeliegene Das Modell wurde f{\"u}r Seegangs- und Str{\"o}mungs-Untersuchungen im Jade-Weser-{\"A}stuar an der deutschen Nordseek{\"u}ste eingesetzt.}, subject = {Hydrodynamik}, language = {de} } @inproceedings{Counsell2000, author = {Counsell, John}, title = {Spatial Database Management and Generation of VRML Models}, doi = {10.25643/bauhaus-universitaet.579}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5791}, year = {2000}, abstract = {The cost of keeping large area urban computer aided architectural design (CAAD) models up to date justifies wider use and access. This paper reviews the potential for collaborative groupwork creation and maintenance of such models and suggests an approach to data entry, data management and generation of appropriate levels of detail models from a Geographic Information System (GIS). Staff at the University of the West of England (UWE) modelled a large area of Bristol to demonstrate millennium landmark proposals. It became swiftly apparent that continued amendment of the model to keep it an accurate reflection of changes on the ground was a major data management problem. Piecing in new CAAD models received from Architectural Practices to visualise them in context as part of the planning negotiation process has often taken staff several days of work for each instance. The model is so complex and proprietary that Bristol City operates a specialist visualisation bureau service. UWE later modelled the environs of the Tower of London to support bids for funding and to provide the context for judging the visual impact of iterative design development. Further research continued to develop more effective approaches to. Data conversion and amalgamation from all the diverse sources was the major impediment to effective group working to create the models. It became apparent that a GIS would assist retrieving all the appropriate data that described the part of the model under creation. It was possible to predict that management of many historic part models stepping back through time, allowing for different expert interpretations to co-exist would be in itself a major task requiring a spatial database/GIS. UWE started afresh from the original source data, to explore the collaborative use of GIS and Virtual Reality Modelling Language (VRML) to integrate models and interventions from various sources and to generate an overall navigable interactive whole. Current exploration of the combination of event driven behaviours and Structured Query Language is seeking to define how appropriately to modify objects in the VRML model on demand. This is beginning to realise the potential for use of this process for: asynchronous group modelling on the lines of a collaborative virtual design studio; historic building maintenance management; visitor management; interpretation of historic sites to visitors and public planning information.}, subject = {Raumordnung}, language = {en} } @inproceedings{ChangwanHaasCaldas2004, author = {Changwan, Kim and Haas, Carl and Caldas, Carlos}, title = {Spatial data acquisition, integration, and modeling for real-time project life-cycle applications}, doi = {10.25643/bauhaus-universitaet.128}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1280}, year = {2004}, abstract = {Current methods for site modeling employs expensive laser range scanners that produce dense point clouds which require hours or days of post-processing to arrive at a finished model. While these methods produce very detailed models of the scanned scene, useful for obtaining as-built drawings of existing structures, the associated computational time burden precludes the methods from being used onsite for real-time decision-making. Moreover, in many project life-cycle applications, detailed models of objects are not needed. Results of earlier research conducted by the authors demonstrated novel, highly economical methods that reduce data acquisition time and the need for computationally intensive processing. These methods enable complete local area modeling in the order of a minute, and with sufficient accuracy for applications such as advanced equipment control, simple as-built site modeling, and real-time safety monitoring for construction equipment. This paper describes a research project that is investigating novel ways of acquiring, integrating, modeling, and analyzing project site spatial data that do not rely on dense, expensive laser scanning technology and that enable scalability and robustness for real-time, field deployment. Algorithms and methods for modeling objects of simple geometric shape (geometric primitives from a limited number of range points, as well as methods provide a foundation for further development required to address more complex site situations, especially if dynamic site information (motion of personnel and equipment). Field experiments are being conducted to establish performance parameters and validation for the proposed methods and models. Initial experimental work has demonstrated the feasibility of this approach.}, subject = {Bauwerk}, language = {en} } @article{Strukelj1997, author = {Strukelj, A.}, title = {Some Problems in Obtaining the Green's Function of the Layered Soil}, doi = {10.25643/bauhaus-universitaet.538}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5388}, year = {1997}, abstract = {The frame of this paper is the development of methods and procedures for the description of the motion of an arbitrary shaped foundation. Since the infinite half-space cannot be properly described by a model of finite dimensions without violating the radiation condition, the basic problems are infinite dimensions of the half-space as well as its non-homogeneous nature. Consequently, an approach has been investigated to solve this problem indirectly by developing Green's function in which the non-homogeneity and the infiniteness of the half-space has been included. When the Green's function is known, the next step will be the evaluation of contact stresses acting between the foundation and the surface of the half-space through an integral equation. The equation should be solved in the area of the foundation using Green's function as the kernel. The derivation of three-dimensional Green's function for the homogeneous half-space (Kobayashi and Sasaki 1991) has been made using the potential method. Partial differential equations occurring in the problem have been made ordinary ones through the Hankel integral transform. The general idea for obtaining the three-dimensional Green's function for the layered half-space is similar. But in that case some additional phenomena may occur. One of them is the possibility of the appearance of Stonely surface waves propagating along the contact surfaces of layers. Their contribution to the final result is in most cases important enough that they should not be neglected. The main advantage of results presented in comparing to other obtained with numerical methods is their accuracy especially in the case of thin layers because all essential steps of Green's function evaluation except of the contour integration along the branch cut have been made analytically. On the other hand the disadvantage of this method is that the mathematical effort for obtaining the Green's function is increasing drastically with the increase of the number of layers. Future work will therefore be directed in simplifying of the above described process}, subject = {Bodenmechanik}, language = {en} } @article{BucherSchorling1997, author = {Bucher, Christian and Schorling, York}, title = {SLang - the Structural Language : Solving Nonlinear and Stochastic Problems in Structural Mechanics}, doi = {10.25643/bauhaus-universitaet.495}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4957}, year = {1997}, abstract = {Recent developments in structural mechanics indicate an increasing need of numerical methods to deal with stochasticity. This process started with the modeling of loading uncertainties. More recently, also system uncertainty, such as physical or geometrical imperfections are modeled in probabilistic terms. Clearly, this task requires close connenction of structural modeling with probabilistic modeling. Nonlinear effects are essential for a realistic description of the structural behavior. Since modern structural analysis relies quite heavily on the Finite Element Method, it seems to be quite reasonable to base stochastic structural analysis on this method. Commercially available software packages can cover deterministic structural analysis in a very wide range. However, the applicability of these packages to stochastic problems is rather limited. On the other hand, there is a number of highly specialized programs for probabilistic or reliability problems which can be used only in connection with rather simplistic structural models. In principle, there is the possibility to combine both kinds of software in order to achieve the goal. The major difficulty which then arises in practical computation is to define the most suitable way of transferring data between the programs. In order to circumvent these problems, the software package SLang (Structural Language) has been developed. SLang is a command interpreter which acts on a set of relatively complex commands. Each command takes input from and gives output to simple data structures (data objects), such as vectors and matrices. All commands communicate via these data objects which are stored in memory or on disk. The paper will show applications to structural engineering problems, in particular failure analysis of frames and shell structures with random loads and random imperfections. Both geometrical and physical nonlinearities are taken into account.}, subject = {Baustatik}, language = {en} } @inproceedings{SchnellenbachHeldDenkGeibig2003, author = {Schnellenbach-Held, Martina and Denk, Heiko and Geibig, Oliver}, title = {SiReAM - An Agent Based Virtual Marketplace for AEC-Bidding}, doi = {10.25643/bauhaus-universitaet.361}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3611}, year = {2003}, abstract = {Today´s procedures for the awarding of public construction performance contracts are mainly paper-based. Although the usage of electronic means is permitted in the VOB, the regulations are not sufficient yet. Especially software agents within the AEC-bidding process were not considered at all. The acceptance of an agent-based virtual marketplace for AEC-bidding depends on a reliable and trustworthy public key infrastructure according to the (German) digital signature act. Only if confidentiality, integrity, non-repudiation, and authentication are provided reliably, users will assign sensitive business processes like public tendering procedures to software agents. The development of a secure agent-based virtual marketplace for AEC-bidding according to legal regulations is an entirely new approach from a technical as well as from a legal point of view. The objective of this research project is the development of intelligent software-agents which are able to legally call for bids, to calculate proposals, and to award the successful bidder.}, subject = {Ausschreibung}, language = {en} } @inproceedings{HuebnerWalhornKoelke2003, author = {H{\"u}bner, Bj{\"o}rn and Walhorn, Elmar and K{\"o}lke, Andreas}, title = {Simultane L{\"o}sung gekoppelter Struktur-Fluid-Systeme}, doi = {10.25643/bauhaus-universitaet.311}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3114}, year = {2003}, abstract = {Ein simultanes L{\"o}sungsverfahren f{\"u}r Fluid-Struktur-Wechselwirkungen aus dem Bereich des Bauingenieurwesens wird vorgestellt. Die Modellierung der Tragwerksdynamik erfolgt mit der geometrisch nichtlinearen Elastizit{\"a}tstheorie in total Lagrangescher Formulierung. Die Str{\"o}mung wird mit den inkompressiblen Navier-Stokes-Gleichungen beschrieben. Wenn Turbulenzeffekte massgeblich sind, kommen die Reynolds-Gleichungen in Verbindung mit dem k-omega-Turbulenzmodell von Wilcox zum Einsatz. Zur Beschreibung von komplexen freien Oberfl{\"a}chen wird die Level-Set-Methode eingesetzt. Die einheitliche Diskretisierung von Fluid und Struktur mit der Raum-Zeit-Finite-Element-Methode f{\"u}hrt zu einem konsistenten Berechnungsmodell f{\"u}r das gekoppelte System. Da die isoparametrischen Raum-Zeit-Elemente ihre Geometrie in Zeitrichtung {\"a}ndern k{\"o}nnen, erlaubt die Methode eine nat{\"u}rliche Beschreibung des infolge der Strukturbewegung zeitver{\"a}nderlichen Str{\"o}mungsgebiets. Die gewichtete Integralformulierung der Kopplungsbedingungen mit globalen Freiwerten f{\"u}r die Interface-Spannungen sichert eine konservative Kopplung von Fluid und Struktur. Ausgew{\"a}hlte Anwendungsbeispiele zeigen die Leistungsf{\"a}higkeit der entwickelten Methodik und belegen die guten Konvergenzeigenschaften des simultanen L{\"o}sungsverfahrens.}, subject = {Bauwerk}, language = {de} } @inproceedings{FediorHamel, author = {Fedior, Marco and Hamel, Wido}, title = {Simulationsumgebung zur Evaluation von umweltorientierten Verkehrsmanagement-Strategien}, series = {30. Forum Bauinformatik}, booktitle = {30. Forum Bauinformatik}, editor = {Steiner, Maria and Theiler, Michael and Mirboland, Mahsa}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.3867}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190328-38678}, pages = {6}, abstract = {Der vorliegende Beitrag beschreibt die Problematik bei der Prognose verkehrsbedingter Schadstoff-Immissionen. Im Mittelpunkt steht die Entwicklung und der Aufbau einer Simulationsumgebung zur Evaluation von umweltorientierten Verkehrsmanagement-Strategien. Die Simulationsumgebung wird {\"u}ber die drei Felder Verkehr, Emission, Immission entwickelt und findet zun{\"a}chst Anwendung in der Evaluation verkehrlicher Maßnahmen f{\"u}r die Friedberger Landstraße in Frankfurt am Main.}, subject = {Verkehr}, language = {de} } @inproceedings{ReinhardtGarrettAkinci2004, author = {Reinhardt, Jan and Garrett, James H. and Akinci, Burcu}, title = {SiDaCoS: Product and Process Models on Construction Sites}, doi = {10.25643/bauhaus-universitaet.115}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1156}, year = {2004}, abstract = {Site superintendents performing project management tasks on construction sites need to access project documents and need to collect information that they observe while inspecting the site. Often, information that is observed on a construction site needs to be integrated into electronic documents or project control systems. In the future, we expect integrated product and process models to be the medium for storing and handling construction project management information. Even though mobile computing devices today are already capable of storing and handling such integrated product and process data models, the user interaction with such large and complex models is difficult and not adequately addressed in the existing research. In this paper, we introduce a system that supports project management tasks on construction sites effectively and efficiently by making integrated product and process models accessible. In order to effectively and efficiently enter or access information, site superintendents need visual representations of the project data that are flexible with respect to the level of detail, the decomposition structure, and the type of visual representation. Based on this understanding of the information and data collection needs, we developed the navigational model framework and the application Site Data Collection System (SiDaCoS), which implements that framework. The navigational model framework allows site superintendents to create customized representations of information contained in a product and process model that correspond to their data access and data collection needs on site.}, subject = {Mobile Computing}, language = {en} } @article{MoellerBeerGrafetal.1997, author = {M{\"o}ller, B. and Beer, M. and Graf, W. and Hoffmann, Alfred}, title = {Sicherheitsbeurteilung von Tragwerken mit Fuzzy-Modellen}, doi = {10.25643/bauhaus-universitaet.462}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4625}, year = {1997}, abstract = {Die Sicherheit von Tragwerken h{\"a}ngt von der zuverl{\"a}ssigen Modellierung s{\"a}mtlicher Tragwerksparameter ab. {\"U}blicherweise werden diese Parameter als deterministische oder stochastische Gr{\"o}ßen beschrieben. Stochastische Gr{\"o}ßen sind Zufallsgr{\"o}ßen, die unscharfe Informationen {\"u}ber Tragwerksparameter mit Hilfe von Dichtefunktionen erfassen. Nicht alle unscharfen Tragwerksparameter lassen sich als Zufallsgr{\"o}ßen darstellen. Sie k{\"o}nnen jedoch als Fuzzy-Gr{\"o}ßen modelliert werden. Fuzzy-Gr{\"o}ßen beschreiben unscharfe Tragwerksparameter als unscharfe Menge mit Bewertungsfunktion (Zugeh{\"o}rigkeitsfunktion). 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 f{\"u}r eine neue Sicherheitsbeurteilung auf der Grundlage der M{\"o}glichkeitstheorie. Bei der Fuzzy-Analyse ist die alpha-Diskretisierung vorteilhaft einsetzbar. Bei fehlender Monotonie der deterministischen Berechnungen und unter Ber{\"u}cksichtigung der Nichtlinearit{\"a}t wird die Fuzzy-Analyse mit Optimierungsalgorithmen durchgef{\"u}hrt. Zwei Beispiele werden diskutiert: die L{\"o}sung eines transzendenten Eigenwertproblems und eines linearen Gleichungssystems. Die Systemantworten der Fuzzy-Analyse werden der Sicherheitsbeurteilung zugrunde gelegt. F{\"u}r ausgew{\"a}hlte physikalische Gr{\"o}ßen werden Versagensfunktionen definiert. Diese bewerten die M{\"o}glichkeit des Versagens. Mit Hilfe von Min-max-Operationen der Fuzzy-Set-Theorie erh{\"a}lt man aus Versagensfunktion und Fuzzy-Antwort die Versagensm{\"o}glichkeit bzw. die {\"U}berlebensm{\"o}glichkeit. Die ermittelte Versagensm{\"o}glichkeit repr{\"a}sentiert die subjektive Beurteilung der M{\"o}glichkeit, daß das Ereignis \&qout;Versagen\&qout; eintritt. Beispiele zeigen die Unterschiede zwischen der Sicherheitsbeurteilung mittels Fuzzy-Modells und mittels deterministischen Modells.}, subject = {Tragwerk}, language = {de} } @inproceedings{Mueller2000, author = {M{\"u}ller, Karl-Heinz}, title = {Sicherheitsbeurteilung der Grenzlastzust{\"a}nde von Stahlbetontragwerken}, doi = {10.25643/bauhaus-universitaet.605}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-6059}, year = {2000}, abstract = {Die Ber{\"u}cksichtigung stochastischer System- und Lastparameter bei der nach EC zul{\"a}ssigen Analyse des Tragwerksverhaltens unter Ber{\"u}cksichtigung globalen nichtlinearen Systemverhaltens sind notwendig, da dies ein anderes Sicherheitskonzept erfordert. Wird der plastische Grenzlastfaktor (PGLF), der die Ausnutzung der Systemkapazit{\"a}ten bis zum Kollaps erm{\"o}glicht, zur Grenzzustandsbeurteilung herangezogen, wird dies besonders deutlich. F{\"u}r das Modell eines ebenen Stahlbetontragwerks wird starr-ideal-plastisches Materialverhalten vorausgesetzt. Die Bestimmung des PGLFs f{\"u}r ein gegebenes Lastbild kann ausgehend von einem Extremalprinzip {\"u}ber die L{\"o}sung einer Optimierungsaufgabe erfolgen. Diese direkte Bestimmung des Kollapses bereitet aber bei der stochastischen Analyse Schwierigkeiten, da die zugeh{\"o}rigen Grenzzustandsgleichungen (GZG) nicht gutartig sind. Es wird die stochastische Methode des Multi-Modal Importance Sampling (MMIS) vorgeschlagen, die unter Ber{\"u}cksichtigung der Eigenschaften dieses mechanischen Modells die Versagenswahrscheinlichkeit bestimmt, d.h. das Verfahren nimmt auf die nur st{\"u}ckweise Stetigkeit GZG des speziellen Problems R{\"u}cksicht. Es setzt die zugeh{\"o}rige Grenzzustandsfunktion voraus. Die wesentlichen Bemessungspunkte werden durch Anwendung des Betaverfahrens gesucht und dann mit einem Importance-Sampling-Algorithmus mit multimodaler Sampling Dichte die Versagenswahrscheinlichkeit bestimmt . Das Verfahren sucht und ber{\"u}cksichtigt die wesentlichen Versagensbereiche des Problems mit vertretbarem Aufwand. Verbesserungen k{\"o}nnten sowohl bei den enthaltenen Such- und Iterationsalgorithmen als auch bei der Wahl der einzelnen Sampling-Dichten erzielt werden, was Gegenstand weiterer Untersuchungen ist.}, subject = {Tragwerk}, language = {de} } @inproceedings{Henning2003, author = {Henning, Andr{\´e}}, title = {Short Listing f{\"u}r multikriterielle Job-Shop Scheduling Probleme}, doi = {10.25643/bauhaus-universitaet.298}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2988}, year = {2003}, abstract = {In ersten Teil des Vortrages wird eine Heuristik zur Approximation der Pareto Menge multikriterielle verallgemeinerter Job-Shop Scheduling-Probleme vorgestellt. Der Algorithmus basiert auf einer genetischen lokale Suche Heuristik. Die Mittelwertbildung der Startzeiten der Vorg{\"a}nge wurde hierbei als Rekombinationsoperator verwendet. Als lokale Suche wurde ein Threshold Accepting Algorithmus implementiert. Der Algorithmus wurde auf einer großen Menge von Benchmark-Instanzen und den Zielfunktionen Makespan, Tardiness, Lateness und Summe der Fertigstellungszeiten getestet. Die Ergebnisse zu den verschiedenen Zielfunktionen werden vorgestellt. Die vom Algorithmus erzeugte Approximation der Pareto Menge kann eine große Anzahl von L{\"o}sungen enthalten. Aus dieser Menge muss der Entscheidungstr{\"a}ger eine L{\"o}sung ausw{\"a}hlen. Da die Datenmenge schon bei moderaten Problemdimensionen sehr umfangreich wird, stellt dies ein Problem f{\"u}r den Entscheider dar. Deshalb muss die große Menge der L{\"o}sungen auf eine {\"u}berschaubare Anzahl reduziert werden. Bei dieser Reduktion der L{\"o}sungen muss die Diversit{\"a}t der verbleibenden L{\"o}sungen beachtet werden. Diese Reduzierung wird als Short Listing bezeichnet und im zweiten Teil des Vortrages vorgestellt. Im ersten Schritt des Short Listings werden die L{\"o}sungen mittels Abstandsmaßen im L{\"o}sungsraum geclustert. Die dazu verwendeten Abstandsmaße werden auf den Permutationen der Vorg{\"a}nge auf den Ressourcen definiert. Es wurden f{\"u}nf Abstandsmaße und zwei Clusterverfahren, ein hierarchisches und ein nicht-hierarchisches, untersucht. Im zweiten Schritt wird aus jedem Cluster jeweils eine L{\"o}sung ausgew{\"a}hlt und dem Entscheidungstr{\"a}ger vorgelegt. Dabei wurden zwei Methoden untersucht. Im ersten Fall wurde die bez{\"u}glich einer Ranking-Funktion beste L{\"o}sung und im zweiten Fall die Medianl{\"o}sung bez{\"u}glich des Abstandsmaßes ausgew{\"a}hlt. Die Abstandsmaße, Clusteralgorithmen und Auswahlmethoden wurden auf einer großen Menge von Benchmark-Instanzen verglichen. Die Ergebnisse werden im Vortrag vorgestellt.}, subject = {Reihenfolgeproblem}, language = {de} } @article{EmelichevGirlichPodkopaev1997, author = {Emelichev, V. A. and Girlich, E. and Podkopaev, D. P.}, title = {Several kinds of Stability of efficient Solutions in Vector Trajectorial discrete Optimization Problem}, doi = {10.25643/bauhaus-universitaet.503}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5030}, year = {1997}, abstract = {This work was partially supported by DAAD, Fundamental Researches Foundation of Belarus and International Soros Science Education Program We consider a vector discrete optimization problem on a system of non- empty subsets (trajectories) of a finite set. The vector criterion of the pro- blem consists partial criterias of the kinds MINSUM, MINMAX and MIN- MIN. The stability of eficient (Pareto optimal, Slater optimal and Smale op- timal) trajectories to perturbations of vector criterion parameters has been investigated. Suficient and necessary conditions of eficient trajectories local stability have been obtained. Lower evaluations of eficient trajectories sta- bility radii, and formulas in several cases, have been found for the case when l(inf) -norm is defined in the space of vector criterion parameters.}, subject = {Diskrete Optimierung}, language = {en} } @article{Dzwigon1997, author = {Dzwigon, Wieslaw}, title = {Sch{\"a}tzung der Verkehrs-Verteilung (O-D Matrix) bei der Anwendung der Verkehrsst{\"a}rkemessung in den Straßenquerschnitten}, doi = {10.25643/bauhaus-universitaet.464}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4647}, year = {1997}, abstract = {O-D Matrix sind die wichtigste Informationsquelle, die den Bedarf an Transport in der Stadt betrifft. Sie dienen den richtigen Bildung von Straßennetz und {\"O}ffentlichen Personen Verkehrslinien. Anhand diesen Grundlagen gerechnet man Verkehrsst{\"a}rken, die zur Dimensionierung der Verkehrsinfrastruktur benutzt werden. Im Verkehrsplannung zur Rechnung O-D Matrix wird Vier - Stufen - Methode angewendet. In dieser Methode verwendet man die Angaben aus den Haushaltsumfragen und aus den Kordonumfragen. Diese Methode fordert einen großen Arbeitsaufwand und Kosten. Hier wird die andere Methode dargestellt. Bei Sch{\"a}tzung der O-D Matrix verwendet man die Verkehrsst{\"a}rken, die in den Straßenquerschnitten gemessen werden. Wir brauchen gemessene Verkehrsst{\"a}rken auch f{\"u}r andere Ziele (z. B. f{\"u}r Signalsteuerung, f{\"u}r Beobachtung des Motorisierungstrendes). Darum ist diese Methode billiger als das traditionelle Verfahren. In diesen Methode haben wir zwei M{\"o}glichkeiten. Die erste - von Verkehrsst{\"a}rkemessungen kann man O-D Matrix direkt sch{\"a}tzen. Und zweite M{\"o}glichkeit - zuerst rechnen wir die Verkehrserzeugungen und sp{\"a}ter O-D Matrix. Das zweite Verfahren hat einen wesentlichen Vorteil und zwar, anhand der Verkehrserzeugungen ist es m{\"o}glich alle Elemente O-D Matrix zu rechnen. Bei der Sch{\"a}tzung der O-D Matrix unmittelbar von den Messungen (das erste Verfahren) bekommt man nur diese Elemente, die in den beobachtenen Straßenquerschnitten auftreten.}, subject = {Stadtverkehr}, language = {de} } @inproceedings{AdamskiBryniarska1997, author = {Adamski, A. and Bryniarska, Z.}, title = {Schedule Synchronisation in public Transport by Tabu Search and Genetic Method}, doi = {10.25643/bauhaus-universitaet.414}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4146}, year = {1997}, abstract = {This paper concerns schedule synchronization problems in public transit networks. In particular, it consists of three main parts. In the first the subject area is introduced, the terms are defined and framework for optimal synchronization in the form of problem representation and formulation is proposed. The second part is devoted to transfer synchronization problem when passengers changing transit lines at transfer points. The intergrated Tabu Search and Genetic solution method is developed with respect to this specific problem. The third part deals with headways harmonization problem i.e. synchronization of different transit lines schedules on a common segments of routes. For the solution of this problem a new bilevel optimization method is proposed with zones harmonization at the bottom level and co-ordination of zones, by time buffers assigned to timing points, at the upper level. Finally, the synchronization problems are numerically illustrated by real-life examples of the public transport lines in Cracow.}, subject = {{\"O}ffentlicher Personennahverkehr}, language = {en} } @inproceedings{LehnerHartmann2004, author = {Lehner, Karlheinz and Hartmann, Dietrich}, title = {Scenarios for the deployment of distributed engineering applications}, doi = {10.25643/bauhaus-universitaet.147}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1476}, year = {2004}, abstract = {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.}, subject = {Ingenieurbau}, language = {en} } @inproceedings{HartmannSmarslyLahmer, author = {Hartmann, Veronika and Smarsly, Kay and Lahmer, Tom}, title = {ROBUST SCHEDULING IN CONSTRUCTION ENGINEERING}, series = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar}, booktitle = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar}, editor = {G{\"u}rlebeck, Klaus and Lahmer, Tom}, organization = {Bauhaus-Universit{\"a}t Weimar}, issn = {1611-4086}, doi = {10.25643/bauhaus-universitaet.2799}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170314-27994}, pages = {5}, abstract = {In construction engineering, a schedule's input data, which is usually not exactly known in the planning phase, is considered deterministic when generating the schedule. As a result, construction schedules become unreliable and deadlines are often not met. While the optimization of construction schedules with respect to costs and makespan has been a matter of research in the past decades, the optimization of the robustness of construction schedules has received little attention. In this paper, the effects of uncertainties inherent to the input data of construction schedules are discussed. Possibilities are investigated to improve the reliability of construction schedules by considering alternative processes for certain tasks and by identifying the combination of processes generating the most robust schedule with respect to the makespan of a construction project.}, subject = {Angewandte Informatik}, language = {en} } @article{LikhitruangsilpIoannou2004, author = {Likhitruangsilp, Veerasak and Ioannou, Photios}, title = {Risk-sensitive Markov Decision Process for Underground Construction Planning and Estimating}, doi = {10.25643/bauhaus-universitaet.224}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2247}, year = {2004}, abstract = {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.}, subject = {Mehragentensystem}, language = {en} } @inproceedings{PetkovChristov2003, author = {Petkov, Zdravko B. and Christov, Christo T.}, title = {Response Spectra Evaluation Including Pounding Effect}, doi = {10.25643/bauhaus-universitaet.346}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3464}, year = {2003}, abstract = {Most of the existing seismic resistant design codes are based on the response spectrum theory. The influence of inelastic deformations can be evaluated by considering inelastic type of resisting force and then the inelastic spectrum is considerably different from the elastic one. Also, the influence of stiffness degradation and strength deterioration can be accounted for by including more precise models from material point of view. In some recent papers the corresponding changes in response spectra due to the P- {\"A} effect are discussed. The experience accumulated from the recent earthquakes indicates that structural pounding may considerably influence the response of structures and should be taken into account in design procedures. The most convenient way to do that is to predict the influence of the pounding on the response spectra for accelerations, velocities and displacements. Generally speaking the contact problems such as pounding are characterized by large extent of nonlinearity and slow convergence of the computational procedures. Thus obtaining spectra where the contact problem is accounted for seems very attractive from engineering point of view because could easy be implemented into the design procedures. However it is worth nothing that there is not rigorous mathematical proof that the original system can be decomposed into single equations related to single degree of freedom systems. It is the porpose of the paper to study the influence of the pounding on the response spectra and to evaluate the amplification due to the impact. For this purpose two adjacent SDOF systems are considered that are able to interact during the vibration process. This problem is solved versus the elastic stiffness ratio, which appears to be very important for such assemblage. The contact between masses is numerically simulated using opening gap elements as links. Comparisons between calculated response spectra and linear response spectra are made in order to derive analytical relationships to simply obtain the contribution of pounding. The results are graphically illustrated in response spectra format and the influence of the stiffness ratio is clarified.}, subject = {Bauwerk}, language = {en} }