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In this paper proposed the application of two-parameters damage model, based on non-linear finite element approach, to the analysis of masonry panels. Masonry is treated as a homogenized material, for which the material characteristics can be defined by using homogenization technique. The masonry panels subjected to shear loading are studied by using the proposed procedure within the framework of three-dimensional analyses. The nonlinear behaviour of masonry can be modelled using concepts of damage theory. In this case an adequate damage function is defined for taking into account different response of masonry under tension and compression states. Cracking can, therefore, be interpreted as a local damage effect, defined by the evolution of known material parameters and by one or several functions which control the onset and evolution of damage. The model takes into account all the important aspects which should be considered in the nonlinear analysis of masonry structures such as the effect of stiffness degradation due to mechanical effects and the problem of objectivity of the results with respect to the finite element mesh. Finally the proposed damage model is validated with a comparison with experimental results available in the literature.
This paper presents results of applying Fuzzy Inference System for estimation of the number of potential Park and Ride users. Usually it is difficult to evaluate the number of users because it depends on human factor and data in the considered system are uncertain. In such situation the traditional mathematical approaches can not take into consideration rough data. Therefore a fuzzy approach can be applied in this case. A fuzzy methodology is treated as a proper way to describe choice of mode of transport, and especially that uncertainty accompanied of choosing process has rather fuzzy character. The proposed approach is based on the Mamdani Fuzzy Inference System and for calculation there is used Matlab software with Fuzzy Logic Toolbox. Mamdani model requires, as an input data, knowledge of the shape of membership function. These functions can be calibrated taking into consideration results of questionnaires conducted among users of Park and Ride system. Due to lack of representative sample of users, one has decided to use results of experts' questionnaires as a input data for calibration the shape of membership functions. Describing factor will be generalized cost of the trip for different modes of transport. Proposed approach consists of two main stages: modeling of share of public/private transport trips and Multimodal model estimating number of Park and Ride users. Verification of presented methodology is treated as an indirect proof. Proposed approach can be applied for estimation of bi-modal split. Then the results are compared with traditional approaches based on logit functions. Comparable results of proposed fuzzy approach with traditional logit models can be treated as a confirmation of chosen methodology.
The concept is presented of the sensitivity analysis of the limit state of the structure with respect to selected basic variables. The sensitivity is presented in the form of the probability distribution of the limit state of the structure. The analysis is performed by the problem-oriented Monte Carlo simulation procedure. The procedure is based on the problem's definition of the elementary event, as a structural limit state. Thus the sample space consists of limit states of the structure. Defined on the sample space the one-dimensional random multiplier is introduced. This multiplier refers to the dominant basic variable (group of variables) of the problem. Numerical procedure results in the set of random numbers. Normalized relative histogram of this set is an estimator of the PDF of the limit state of the structure. Estimators of reliability, or the probability of failure are statistical characteristics of this histogram. The procedure is illustrated by the example of sensitivity analysis of the serviceability limit state of monumental structure. It is the colonnade of Licheń Basilica, situated in central Poland. Limit state of the structure is examined with reference to the upper deck horizontal deflection. Wind actions are taken as dominant variables. An assumption is made that the wind load intensities acting on the lower and on the upper storey of the colonnade, respectively, are identically distributed, but correlated random variables. Three correlation variants of these variables are considered. Relevant limit state histograms are analysed thereafter. The paper ends with the conclusions referring to the method and some general remarks on the fully probabilistic design.
VARIATION OF ROTATIONAL RESTRAINT IN GRID DECK CONNECTION DUE TO CORROSION DAMAGE AND STRENGTHENING
(2006)
The approach to assessment of rotational restraint of stringer-to-crossbeam connection in a deck of 100-year old steel truss bridge is presented. Sensitivity of rotational restraint coefficient of the connection to corrosion damage and strengthening is analyzed. Two criteria of the assessment of the rotational restraint coefficient are applied: static and kinematic one. The former is based on bending moment distribution in the considered member, the latter one – on the member rotation at the given joint. 2D-element model of finite element method is described: webs and flanges are modeled with shell elements, while rivets in the connection – with system of beam and spring elements. The method of rivet modeling is verified by T-stub connection test results published in literature. FEM analyses proved that recorded extent of corrosion damage does not alter the initial rotational restraint of stringer-to-crossbeam connection. Strengthening of stringer midspan influences midspan bending moment and stringer end rotation in a different way. Usually restoring member load bearing capacity means strengthening its critical regions (where the highest stress levels occur). This alters flexural stiffness distribution over member length and influences rotational restraint at its connection to other members. The impact depends on criterion chosen for rotational restraint coefficient assessment.
Car following models are used to describe the behavior of a number of cars on the road dependent on the distance to the car in front. We introduce a system of ordinary differential equations and perform a theoretical and numerical analysis in order to find solutions that reflect various traffic situations. We present three different variations of the model motivated by reality.
In many branches companies often lose the visibility of their human and technical resources of their field service. On the one hand the people in the fieldservice are often free like kings on the other hand they do not take part of the daily communication in the central office and suffer under the lacking involvement in the decisions inside the central office. The result is inefficiency. Reproaches in both directions follow. With the radio systems and then mobile phones the ditch began to dry up. But the solutions are far from being productive.
Die Kommunale Wohnungsgesellschaft mbH Erfurt(KoWo) ist mit ihren rund 20.000 Wohnungen in der Landeshauptstadt das größte Wohnungsunternehmen in Thüringen. Der Immobilienbestand ist heterogen in seinem technischen Zustand und im Bezug auf die unterschiedlichen Lagen der Objekte. Bedingt durch Leerstände und unterschiedliche Modernisierungsmaßnahmen und -stände unterscheidet sich die Wirtschaftlichkeit verschiedener Objekte deutlich. Ohne eine einheitliche Einwertung des Immobilienbestandes im Bezug auf die Objektattraktivität, die Standortqualität und die Objektwirtschaftlichkeit fällt eine langfristige strategische Entwicklung des Immobilienportfolios schwer. Über die Schritte der technischen Bestandserfassung, die Einwertung über ein Scorintmodell, die Abbildung in einem Portfoliomodell mit zugehöriger Normstrategie bis hin zur Weiterverarbeitung der Daten in der 20-jährigen Instandsetzungsplanung wird praxisnah aufgezeigt, wie die Vorgehensweise bei der Einwertung des Immobilienportfolios ist.
Im Bereich der Altbausanierung und der Bestandserfassung im Bauwesen ist es häufig notwendig, bestehende Pläne hinsichtlich des Bauwerkszustandes zu aktualisieren oder, wenn diese Pläne nicht (mehr) zugänglich sind, gänzlich neue Planunterlagen des Ist-Zustandes zu erstellen. Ein komfortabler Weg, diese Bauwerksdaten zu erheben, eröffnet die Technologie der Laservermessung. Der vorliegende Artikel stellt in diesem Zusammenhang Ansätze zur Teilautomatisierung der Generierung eines dreidimensionalen Computermodells eines Bauwerkes vor. Als Ergebnis wird ein Volumenmodell bereitgestellt, in dem zunächst die geometrischen und topologischen Informationen über Flächen, Kanten und Punkte im Sinne eines B-rep Modells beschrieben sind. Die Objekte dieses Volumenmodells werden mit Verfahren aus dem Bereich der künstlichen Intelligenz analysiert und in Bauteilklassen systematisch kategorisiert. Die Kenntnis der Bauteilsemantik erlaubt es somit, aus den Daten ein Bauwerks-Produktmodell abzuleiten und dieses einzelnen Fachplanern – etwa zur Erstellung eines Energiepasses – zugänglich zu machen. Der Aufsatz zeigt den erfolgreichen Einsatz virtueller neuronaler Netze im Bereich der Bestandserfassung anhand eines komplexen Beispiels.
Unconstrained models are very often found in the broad spectrum of different theories of traffic demand models. In these models there are none or only one-sided restrictions influencing the choice of the individual. However in the traffic demand different deciding dependencies of the traffic volume with regard to the specific conditions of the territory structure potentials exist. Kichhoff and Lohse introduced bi- and tri-linearly constrained models to show these dependencies. In principle, the dependencies are described as hard, elastic and open boundary sum criteria. In this article a model is formulated which gets away from these predefined boundary sum criteria and allows a free determination of minimal and maximal boundary sum criteria. The iterative solution algorithm is shown according to a FURNESS procedure at the same time. With the approach of freely selectable minimal and maximal boundary sum criteria the modeling transport planner gets the possibility to show the traffic event even better. Furthermore all common boundary sum criteria can be calculated with this model. Therewith the often necessary and sensible standard and special cases can also be modeled.
Räume und Gebäude sind heute wegen der enormen Funktionalität der technischen Gebäudeausrüstung (TGA) in Kombination mit der sonstigen Ausstattung und den diversen Anwendungsprozessen und Nutzergruppen ohne innovative Konzepte der integrierten Bedienung kaum noch beherrschbar bzw. optimal nutzbar. Dies gilt sowohl für Wohn- als auch für Zweckimmobilien. Die Gebäudeleittechnik (GLT) und die Gebäudeautomation (GA) können hier unter sinnvoller Integration der Möglichkeiten der Mikroelektronik, Multimedia-, Kommunikations- und Informationstechnik erheblich zu nutzbringenden Innovationen beitragen. Die Automobilindustrie hat in den letzten Jahren gezeigt, wie durch einen integralen Systemansatz und durch Einsatz von Elektronik, Kommunikations- und Informationstechnik eine sinnvolle technische Assistenz der Anwender machbar ist. Genannt sei hier das Konzept des Cockpits mit integrierter Funktionsbündelung und der Informationskonzentration am Armaturenbrett. Im Gegensatz zum Automobil ist der Bereich der technischen Gebäudeausstattung in Wohn- und Nutzimmobilien gekennzeichnet durch eine starke Fragmentierung in unterschiedlichste Gewerke unter Beteiligung vieler oft schlecht koordinierter Akteure. Durch das Duisburger inHaus-Innovationszentrum für Intelligente Raum- und Gebäudesysteme der Fraunhofer-Gesellschaft wurden in den letzten Jahren neuartige Konzepte der Systemintegration heterogener Technik auf der Basis von Middleware-Plattformen und Multimedia-Technologien und -Geräten entwickelt, getestet und in die Anwendung getragen. Einer der ersten Systemanwendungen dieses offenen Infrastrukturkonzepts ist die integrierte Systembedienung mit zum Teil völlig neuen Bedienkonzepten und einer starken Bedienungsvereinfachung auch komplexester Technikausrüstungen in Immobilien. Der Beitrag beschreibt nach einer Analyse der Ausgangslage die technologischen Grundzüge der integrierten Systembedienung. Es folgen einige Anwendungsbeispiele und eine zusammenfassende Bewertung mit einem Ausblick auf weiterführende Aktivitäten.
In distributed project organisations and collaboration there is a need for integrating unstructured self-contained text information with structured project data. We consider this a process of text integration in which various text technologies can be used to externalise text content and consolidate it into structured information or flexibly interlink it with corresponding information bases. However, the effectiveness of text technologies and the potentials of text integration greatly vary with the type of documents, the project setup and the available background knowledge. The goal of our research is to establish text technologies within collaboration environments to allow for (a) flexibly combining appropriate text and data management technologies, (b) utilising available context information and (c) the sharing of text information in accordance to the most critical integration tasks. A particular focus is on Semantic Service Environments that leverage on Web service and Semantic Web technologies and adequately support the required systems integration and parallel processing of semi-structured and structured information. The paper presents an architecture for text integration that extends Semantic Service Environments with two types of integration services. Backbone to the Information Resource Sharing and Integration Service is a shared environment ontology that consolidates information on the project context and the available model, text and general linguistic resources. It also allows for the configuration of Semantic Text Analysis and Annotation Services to analyse the text documents as well as for capturing the discovered text information and sharing it through semantic notification and retrieval engines. A particular focus of the paper is the definition of the overall integration process configuring a complementary set of analyses and information sharing components.
The use of virtual reality techniques in the development of educational applications brings new perspectives to the teaching of subjects related to the field of civil construction in Civil Engineering domain. In order to obtain models, which would be able to visually simulate the construction process of two types of construction work, the research turned to the techniques of geometric modelling and virtual reality. The applications developed for this purpose are concerned with the construction of a cavity wall and a bridge. These models make it possible to view the physical evolution of the work, to follow the planned construction sequence and to visualize details of the form of every component of the works. They also support the study of the type and method of operation of the equipment necessary for these construction procedures. These models have been used to distinct advantage as educational aids in first-degree courses in Civil Engineering. Normally, three-dimensional geometric models, which are used to present architectural and engineering works, show only their final form, not allowing the observation of their physical evolution. The visual simulation of the construction process needs to be able to produce changes to the geometry of the project dynamically. In the present study, two engineering construction work models were created, from which it was possible to obtain three-dimensional models corresponding to different states of their form, simulating distinct stages in their construction. Virtual reality technology was applied to the 3D models. Virtual reality capacities allow the interactive real-time viewing of 3D building models and facilitate the process of visualizing, evaluating and communicating.
Die effektive Kooperation aller beteiligten Fachplaner im Bauplanungsprozess ist die Voraussetzung für wirtschaftliches und qualitativ hochwertiges Bauen. Bauprojektorganisationen bestehen in der Regel aus zahlreichen unabhängigen Planungspartnern, die örtlich verteilt spezifische Planungsaufgaben bearbeiten und die Ergebnisse in Teilproduktmodellen ablegen. Da Planungsprozesse im Bauwesen stark arbeitsteilig ablaufen, sind die Teilproduktmodelle der einzelnen Fachplanungen in hohem Maße voneinander abhängig. Ziel des hier vorgestellten Ansatzes ist die Integration der Teilproduktmodelle der Gebäudeplanung in einem netzwerkbasierten Modellverbund am Beispiel der Brandschutzplanung. Im Beitrag werden die Probleme der Verteiltheit und insbesondere der semantischen Heterogenität der involvierten Teilproduktmodelle betrachtet. Der verteilte Zugriff wird mithilfe mobiler Software-Agenten realisiert. Die Agenten können sich dabei frei im netzwerkbasierten Planungsverbund bewegen und agieren als Vertreter der Fachplaner. Das Problem der semantischen Heterogenität der Teilproduktmodelle wird auf der Basis von Ontologien gelöst. Dazu werden erstens Domänenontologien entwickelt, die Objekte der realen Welt einer abgeschlossenen Domäne, hier des Brandschutzes, abbilden. Zweitens werden Applikationsontologien entwickelt, die die einzelnen proprietären Datenhaltungen (im Sinne von Teilproduktmodellen) der jeweiligen Fachplanungen repräsentieren. Beide Ontologien werden mit einem regelbasierten Ansatz verknüpft. Im vorgestellten Anwendungsfall Brandschutz dient die Domänenontologie als einheitliche Schnittstelle für den Zugriff auf die verteilten Modelle und abstrahiert dabei von deren Datenbankspezifika und proprietären Schemata. Mithilfe von mobilen Agenten und semantischen Technologien kann so eine Plattform zur Verfügung gestellt werden, die erstens die dynamische Integration von Ressourcen in den Planungsverbund erlaubt und zweitens auf deren Basis unabhängig von der Verteiltheit und Heterogenität der eingebundenen Ressourcen ingenieurgerechte Verarbeitungsmethoden realisiert werden können.
Durch die Betrachtung des Produktions-Prozesses als zentrales Transformationselement wird die Struktur der Bauproduktion realitätsnah gefasst. Die Integration der prozessorientierten Kostendefinition setzt relevante Kostenparameter und Produktionsfaktoren so in Beziehung, dass sie im Einklang mit der realen Kostenstruktur und Kostendynamik einer Baustelle stehen. Die Beziehung zwischen Bauzeit und Kosten wird direkt erfasst und ausgewertet. Der hohen Dynamik der Bauproduktion zwischen kapazitätsbeschränkten Einsatzmitteln und Produktionsprozessen wurde durch das Poolmodell und der Simulation als Berechnungsmethode Rechnung getragen. Eine einfache Modellierung von sich zyklusartig wiederholenden Arbeitsvorgängen (Taktplanung) ist möglich. Die Taktbildung vollzieht sich bei der Simulation durch Kapazitätsbeschränkungen ohne Zutun des Benutzers. Durch eine Optimierungsmethode kann automatisiert nach der kostengünstigsten oder zeitlich schnellsten Produktionsvariante gesucht werden
MODELLING THE PLASTIC HINGE IN THE STATICALLY INDETERMINABLE REINFORCED CONCRETE BAR ELEMENTS
(2006)
The paper presents the example numerical model to calculate the reinforced concrete bar structures. Usually applied methods of structure dimensioning do not include the case of plastic hinges occurrence under the limit load of construction. The model represented by A. Borcz is based on the differential equation of deflection line of the beam and it includes the effects of rearrangement of the internal forces and reological effects. The experimental parameters obtained in earlier investigations describe effects resulting from the rise of plastic hinges in the proposed equation.
The paper presents a linear static analysis on continuous orthotropic thin-walled shell structures simply supported at the transverse ends with a random deformable contour of the cross section. The external loads can be random as well. The class of this structures involves most of the bridges, scaffold bridges, some roof structures etc. A numerical example of steel continuous structures on five spans with an open contour of the cross-section has been solved. The examination of the structure has used the following two computation models: a prismatic structure consisting of isotropic strips, a plates and ribs, with considering their real interaction, and a smooth orthotropic plate equivalent to the structure in the first model. The displacements and forces of the structure characterizing its stressed and deformed condition have been determined. The results obtained from the two solutions have been analyzed. The study on the structure is made with the force method in combination with the analytical finite strip method (AFSM) in displacements. The basic system is obtained by separating the superstructure from the understructure at the places of intermediate supports and consists of two parts. The first part is a single span thin-walled prismatic shell structure; the second part presents supports (columns, space frames etc.). The connection between the superstructure and intermediate supports is made under random supporting conditions. The forces at the supporting points in the direction of the connections removed are assumed to be the basic unknowns of the force method. The solution of the superstructure has been accomplished by the AFSM in displacements. The structure is divided in only one (transverse) direction into a finite number of plain strips connected to each other in longitudinal linear nodes. The three displacements of the points on the node lines and the rotation around those lines have been assumed to be the basic unknown in each node. The boundary conditions of each strip of the basic system correspond to the simply support along the transverse ends and the restraint along the longitudinal ones. The particular strip of the basic system has been solved by the method of the single trigonometric series. The method is reduced to solving a discrete structure in displacements and restoring its continuity at the places of the sections made in respect to both the displacements and forces. The two parts of the basic system have been solved in sequence under the action of single values of each of the basic unknowns and with the external load. The solution of the support part is accomplished using software for analyzing structures by the FEM. The basic unknown forces have been determined from system of canonic equations, the conditions of the deformations continuity on the places of the removed connections under superstructure and intermediate supports. The final displacements and forces at a random point of a continuous superstructure have been determined using the principle of superposition. The computations have been carried by software developed with Visual Fortran version 5.0 for PC.
The paper is dedicated to decidability exploration of market segmentation problem with the help of linear convolution algorithms. Mathematical formulation of this problem represents interval task of bipartite graph cover by stars. Vertices of the first partition correspond to types of commodities, vertices of the second – to customers groups. Appropriate method is offered for interval problem reduction to two-criterion task that has one implemented linear convolution algorithm. Unsolvability with the help of linear convolution algorithm of multicriterion, and consequently interval, market segmentation problem is proved.