TY - CHAP A1 - Baitsch, Matthias A1 - Hartmann, Dietrich ED - Gürlebeck, Klaus ED - Könke, Carsten T1 - A FRAMEWORK FOR THE INTERACTIVE VISUALIZATION OF ENGINEERING MODELS N2 - Interactive visualization based on 3D computer graphics nowadays is an indispensable part of any simulation software used in engineering. Nevertheless, the implementation of such visualization software components is often avoided in research projects because it is a challenging and potentially time consuming task. In this contribution, a novel Java framework for the interactive visualization of engineering models is introduced. It supports the task of implementing engineering visualization software by providing adequate program logic as well as high level classes for the visual representation of entities typical for engineering models. The presented framework is built on top of the open source visualization toolkit VTK. In VTK, a visualization model is established by connecting several filter objects in a so called visualization pipeline. Although designing and implementing a good pipeline layout is demanding, VTK does not support the reuse of pipeline layouts directly. Our framework tailors VTK to engineering applications on two levels. On the first level it adds new – engineering model specific – filter classes to VTK. On the second level, ready made pipeline layouts for certain aspects of engineering models are provided. For instance there is a pipeline class for one-dimensional elements like trusses and beams that is capable of showing the elements along with deformations and member forces. In order to facilitate the implementation of a graphical user interface (GUI) for each pipeline class, there exists a reusable Java Swing GUI component that allows the user to configure the appearance of the visualization model. Because of the flexible structure, the framework can be easily adapted and extended to new problem domains. Currently it is used in (i) an object-oriented p-version finite element code for design optimization, (ii) an agent based monitoring system for dam structures and (iii) the simulation of destruction processes by controlled explosives based on multibody dynamics. Application examples from all three domains illustrates that the approach presented is powerful as well as versatile. KW - Architektur KW - CAD KW - Computerunterstütztes Verfahren Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170327-29194 UR - http://euklid.bauing.uni-weimar.de/ikm2006/index.php_lang=de&what=papers.html ER - TY - CHAP A1 - Baitsch, Matthias A1 - Hartmann, Dietrich T1 - Object Oriented Finite Element Analysis for Structural Optimization using p-Elements N2 - The optimization of continuous structures requires careful attention to discretization errors. Compared to ordinary low order formulation (h-elements) in conjunction with an adaptive mesh refinement in each optimization step, the use of high order finite elements (so called p-elements) has several advantages. However, compared to the h-method a higher order finite element analysis program poses higher demands from a software engineering point of view. In this article the basics of an object oriented higher order finite element system especially tailored to the use in structural optimization is presented. Besides the design of the system, aspects related to the employed implementation language Java are discussed. KW - Konzipieren KW - Bauwerk KW - Finite-Elemente-Methode Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1089 ER - TY - CHAP A1 - Bilek, Jochen A1 - Hartmann, Dietrich T1 - Agentenbasiertes Kooperationsmodell zur Unterstützung vernetzter Planungsprozesse in der Tragwerksplanung N2 - Die heutige Situation in der Tragwerksplanung ist durch das kooperative Zusammenwirken einer größeren Anzahl von Fachleuten verschiedener Disziplinen (Architektur, Tragwerksplanung, etc.) in zeitlich befristeten Projektgemeinschaften gekennzeichnet. Bei der Abstimmung der hierdurch bedingten komplexen, dynamischen und vernetzten Planungsprozesse kommt es dabei häufig zu Planungsmängeln und Qualitätseinbußen. Dieser Artikel zeigt auf, wie mit Hilfe der Agententechnologie Lösungsansätze zur Verbesserung der Planungssituation erreicht werden können. Hierzu wird ein Agentenmodell für die vernetzt-kooperative Tragwerksplanung vorgestellt und anhand der Planung einer Fußgängerbogenbrücke anschaulich demonstriert. Das Agentenmodell erfasst (1) die beteiligten Fachplaner und Organisationen, (2) die tragwerksspezifischen Planungsprozesse, (3) die zugehörigen (Teil-)Produktmodelle und (4) die genutzte (Ingenieur-)Software. Hieraus leiten sich die drei Teilmodelle (1) agentenbasiertes Kooperationsmodell, (2) agentenbasierte Produktmodellintegration und (3) Modell zur agentenbasierten Software-Integration ab. Der Fokus des Artikels liegt auf der Darstellung des agentenbasierten Kooperationsmodells. KW - Tragwerk KW - Planung KW - Computerunterstütztes Verfahren Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2791 ER - TY - CHAP A1 - Erlemann, Kai A1 - Hartmann, Dietrich ED - Gürlebeck, Klaus ED - Könke, Carsten T1 - PARALLELIZATION OF A MICROSCOPIC TRAFFIC SIMULATION SYSTEM USING MPIJAVA N2 - Traffic simulation is a valuable tool for the design and evaluation of road networks. Over the years, the level of detail to which urban and freeway traffic can be simulated has increased steadily, shifting from a merely qualitative macroscopic perspective to a very detailed microscopic view, where the behavior of individual vehicles is emulated realistically. With the improvement of behavioral models, however, the computational complexity has also steadily increased, as more and more aspects of real-life traffic have to be considered by the simulation environment. Despite the constant increase in computing power of modern personal computers, microscopic simulation stays computationally expensive, limiting the maximum network size than can be simulated on a single-processor computer in reasonable time. Parallelization can distribute the computing load from a single computer system to a cluster of several computing nodes. To this end, the exisiting simulation framework had to be adapted to allow for a distributed approach. As the simulation is ultimately targeted to be executed in real-time, incorporating real traffic data, only a spatial partition of the simulation was considered, meaning the road network has to be partitioned into subnets of comparable complexity, to ensure a homogenous load balancing. The partition process must also ensure, that the division between subnets does only occur in regions, where no strong interaction between the separated road segments occurs (i.e. not in the direct vicinity of junctions). In this paper, we describe a new microscopic reasoning voting strategy, and discuss in how far the increasing computational costs of these more complex behaviors lend themselves to a parallelized approach. We show the parallel architecture employed, the communication between computing units using MPIJava, and the benefits and pitfalls of adapting a single computer application to be used on a multi-node computing cluster. KW - Architektur KW - CAD KW - Computerunterstütztes Verfahren Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170327-29516 UR - http://euklid.bauing.uni-weimar.de/ikm2006/index.php_lang=de&what=papers.html ER - TY - CHAP A1 - Galffy, Mozes A1 - Baitsch, Matthias A1 - Wellmann Jelic, Andres A1 - Hartmann, Dietrich ED - Gürlebeck, Klaus ED - Könke, Carsten T1 - LIFETIME-ORIENTED OPTIMIZATION OF BRIDGE TIE RODS EXPOSED TO VORTEX-INDUCED ACROSS-WIND VIBRATIONS N2 - In recent years, damages in welded connections plates of vertical tie rods of several arched steel bridges have been reported. These damages are due to fatigue caused by wind-induced vibrations. In the present study, such phenomena are examined, and the corresponding lifetime of a reference bridge in Münster-Hiltrup, Germany, is estimated, based on the actual shape of the connection plate. Also, the results obtained are compared to the expected lifetime of a connection plate, whose geometry has been optimized separately. The structural optimization, focussing on the shape of the cut at the hanger ends, has been carried out using evolution strategies. The oscillation amplitudes have been computed by means of the Newmark-Wilson time-step method, using an appropriate load model, which has been validated by on-site experiments on the selected reference bridge. Corresponding stress-amplitudes are evaluated by multiplying the oscillation amplitudes with a stress concentration factor. This factor has been computed on the basis of a finite element model of the system "hanger-welding-connection plate", applying solid elements, according to the notch stress approach. The damage estimation takes into account the stochastics of the exciting wind process, as well as the stochastics of the material parameters (fatigue strength) given in terms of Woehler-curves. The shape optimization results in a substantial increase of the estimated hanger lifetime. The comparison of the lifetimes of the bulk plate and of the welding revealed that, in the optimized structure, the welding, being the most sensitive part in the original structure, shows much more resistance against potential damages than the bulk material. KW - Architektur KW - CAD KW - Computerunterstütztes Verfahren Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170327-29561 UR - http://euklid.bauing.uni-weimar.de/ikm2006/index.php_lang=de&what=papers.html ER - TY - JOUR A1 - Galffy, Mozes A1 - Wellmann Jelic, Andres A1 - Hartmann, Dietrich T1 - Lifetime-oriented modelling of vortex-induced across-wind vibrations on bridge tie rods N2 - The influence of vortex-induces vibrations on vertical tie rods has been proved as a determinant load factor in the lifetime-oriented dimensioning of arched steel bridges. Particularly, the welded connection plates between the suspenders and the arches often exhibit cracks induced primarily rods. In this context, the synchronization of the vortex-shedding to the rod motion in a critical wind velocity range, the so-called lock-in effect, is of essential interest. KW - Finite-Elemente-Methode KW - Physikalisches Verfahren KW - Brückenbau KW - Schwingung Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2536 ER - TY - CHAP A1 - Hartmann, Dietrich A1 - Galffy, Mozes A1 - Wellmann Jelic, Andres T1 - Lebensdauerorientierter Entwurf der Hängestangen bei Bogenbrücken - Modellierung als Mehrebenenproblem N2 - Der lebensdauerorientierte Entwurf von Stabbogenbrücken, mit Zuschnitt auf die Auslegung von Hängern, die durch Ermüdung infolge wirbelinduzierter Querschwingungen gefährdet sind, wird als stochastisches semi-infinites Optimierungsproblem formuliert. Zur Lösung dieses Problems sind mehrere Modellierungsebenen erforderlich, so dass ein Mehrebenenproblem entsteht. Es wird der derzeitige Entwicklungs- und Implementierungsstand bei der Umsetzung des Mehrebenenproblems in ein Entwurfsleitsystem (Software) aufgezeigt. Außerdem werden die Konzepte der noch ausstehenden Forschungsarbeit, die bereits erfolgreich beim lebensdauerorientierten Entwurf von Industriehallen mit Rahmensystem als Haupttragwerk eingesetzt wurden, diskutiert und ihre Einbildung in die bisher umgesetzte Forschungsarbeit erläutert. KW - Bogenbrücke KW - Zugstab KW - Optimierung KW - Lebensdauer KW - Materialermüdung Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-3046 ER - TY - CHAP A1 - Hartmann, Dietrich A1 - Meißner, Udo F. A1 - Rueppel, Uwe T1 - Integration of Productmodel Databases into Multi-Agent Systems N2 - This paper deals with two different agent-based approaches aimed at the incorporation of complex design information into multi-agent planning systems. The first system facilitates collaborative structural design processes, the second one supports fire engineering in buildings. Both approaches are part of two different research projects that belong to the DFG1 priority program 1103 entitled “Network-based Co-operative Planning Processes in Structural Engineering“ (DFG 2000). The two approaches provide similar database wrapper agents to integrate relevant design information into two multi-agent systems: Database wrapper agents make the relevant product model data usable for further agents in the multi-agent system, independent on their physical location. Thus, database wrapper agents act as an interface between multi-agent system and heterogeneous database systems. The communication between the database wrapper agents and other requesting agents presumes a common vocabulary: a specific database ontology that maps database related message contents into database objects. Hereby, the software-wrapping technology enables the various design experts to plug in existing database systems and data resources into a specific multi-agent system easily. As a consequence, dynamic changes in the design information of large collaborative engineering projects are adequately supported. The flexible architecture of the database wrapper agent concept is demonstrated by the integration of an XML and a relational database system. KW - Ingenieurbau KW - Verteiltes System KW - Planungsprozess KW - Modellierung KW - Mehragentensystem Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1410 ER - TY - CHAP A1 - Lehner, Karlheinz A1 - Hartmann, Dietrich ED - Gürlebeck, Klaus ED - Könke, Carsten T1 - USING INTERVAL ANALYSIS FOR STRUCTURAL ENGINEERING PROBLEMS N2 - Interval analysis extends the concept of computing with real numbers to computing with real intervals. As a consequence, some interesting properties appear, such as the delivery of guaranteed results or confirmed global values. The former property is given in the sense that unknown numerical values are in known to lie in a computed interval. The latter property states that the global minimum value, for example, of a given function is also known to be contained in a interval (or a finite set of intervals). Depending upon the amount computation effort invested in the calculation, we can often find tight bounds on these enclosing intervals. The downside of interval analysis, however, is the mathematically correct, but often very pessimistic size of the interval result. This is in particularly due to the so-called dependency effect, where a single variable is used multiple times in one calculation. Applying interval analysis to structural analysis problems, the dependency has a great influence on the quality of numerical results. In this paper, a brief background of interval analysis is presented and shown how it can be applied to the solution of structural analysis problems. A discussion of possible improvements as well as an outlook to parallel computing is also given. KW - Architektur KW - CAD KW - Computerunterstütztes Verfahren Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170327-29844 UR - http://euklid.bauing.uni-weimar.de/ikm2006/index.php_lang=de&what=papers.html ER - TY - CHAP A1 - Lehner, Karlheinz A1 - Hartmann, Dietrich T1 - Scenarios for the deployment of distributed engineering applications N2 - 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. KW - Ingenieurbau KW - Verteiltes System KW - Planungsprozess KW - Modellierung KW - Internet Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1476 ER -