@article{ZhuangHuangLiangetal., author = {Zhuang, Xiaoying and Huang, Runqiu and Liang, Chao and Rabczuk, Timon}, title = {A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage}, series = {Mathematical Problems in Engineering}, journal = {Mathematical Problems in Engineering}, doi = {10.1155/2014/179169}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170428-31726}, abstract = {Renewable energy resources such as wind and solar are intermittent, which causes instability when being connected to utility grid of electricity. Compressed air energy storage (CAES) provides an economic and technical viable solution to this problem by utilizing subsurface rock cavern to store the electricity generated by renewable energy in the form of compressed air. Though CAES has been used for over three decades, it is only restricted to salt rock or aquifers for air tightness reason. In this paper, the technical feasibility of utilizing hard rock for CAES is investigated by using a coupled thermo-hydro-mechanical (THM) modelling of nonisothermal gas flow. Governing equations are derived from the rules of energy balance, mass balance, and static equilibrium. Cyclic volumetric mass source and heat source models are applied to simulate the gas injection and production. Evaluation is carried out for intact rock and rock with discrete crack, respectively. In both cases, the heat and pressure losses using air mass control and supplementary air injection are compared.}, subject = {Energiespeicherung}, language = {en} } @inproceedings{RueppelMeissnerGreb2004, author = {Rueppel, Uwe and Meißner, Udo F. and Greb, Steffen}, title = {A Petri Net based Method for Distributed Process Modelling in Structural Engineering}, doi = {10.25643/bauhaus-universitaet.133}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1338}, year = {2004}, abstract = {The contribution introduces a method for the distributed process modelling in order to support the process orientation in Structural Engineering, i.e., the modelling, analysis and management of planning processes. The approach is based on the Petri Net theory for the modelling of planning processes and workflows in Structural Engineering. Firstly, a central and coarse process model serves as a pre-structuring system for the detailed modelling of the technical planning activities. Secondly, the involved planning participants generate distributed process models with detailed technical workflow information. Finally, these distributed process models will be combined in the central workflow net. The final net is of great importance for the process orientation in Structural Engineering, i.e., the identification, publication, analysis, optimization and finally the management of planning processes.}, subject = {Ingenieurbau}, language = {en} } @article{Rebolj1997, author = {Rebolj, D.}, title = {A Product Model of a Road}, doi = {10.25643/bauhaus-universitaet.458}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4584}, year = {1997}, abstract = {Many errors and delays frequently appear when data is exchanged between particular tasks in the lifecycle of the road. Inter-task connections are therefore of great importance for the quality of the final product. The article describes a product model of a road wich is the kernel of an integrated information system intended to support all important stages of the road lifecycle: design, evaluation (through different analysis procedures), construction, and maintainance. Since particular tasks are often executed at different places and in different companies, the interconnections are supported by a special metafile which contains all specific data of the product model. The concept of the integrated system is object and component oriented. Additionally, existing conventional program packages are included to support some common tasks (methods). A conventional relational database system as well as an open spatial database system with the relevant GIS functionality are included to support the data structures of the model.}, subject = {Straße}, language = {en} } @inproceedings{Olivier2004, author = {Olivier, A. H.}, title = {An application-centred framework for distributed engineering applications}, doi = {10.25643/bauhaus-universitaet.135}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1353}, year = {2004}, abstract = {The conceptual structure of an application that can support the structural analysis task in a distributed collaboratory is described in (van Rooyen and Olivier 2004). The application described there has a standalone component for executing the finite element method on a local workstation in the absence of network access. This application is comparable to current, local workstation based finite element packages. However, it differs fundamentally from standard packages since the application itself, and its objects, are adapted to support distributed execution of the analysis task. Basic aspects of an object-oriented framework for the development of applications which can be used in similar distributed collaboratories are described in this paper. An important feature of this framework is its application-centred design. This means that an application can contain any number of engineering models, where the models are formed by the collection of objects according to semantic views within the application. This is achieved through very flexible classes Application and Model, which are described in detail. The advantages of the application-centred design approach is demonstrated with reference to the design of steel structures, where the finite element analysis model, member design model and connection design model interact to provide the required functionality.}, subject = {Ingenieurbau}, language = {en} } @inproceedings{Raue2003, author = {Raue, Erich}, title = {Anwendung der mathematischen Optimierung bei der Modellbildung und Analyse des nichtlinearen Tragverhaltens von Stahlbetontragwerken}, doi = {10.25643/bauhaus-universitaet.371}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3717}, year = {2003}, abstract = {In den zur{\"u}ckliegenden Jahren wurden an der Professur Massivbau I umfangreiche Untersuchungen zur Modellbildung und rechnerischen Erfassung des Tragverhaltens von Tragwerken und Tragwerkselementen aus Stahlbeton und Spannbeton unter Ber{\"u}cksichtigung von Rißbildungen und Plastizierungen durchgef{\"u}hrt. Diesen Untersuchungen liegt als einheitliches methodisches Konzept der mathematischen Problembeschreibung und Probleml{\"o}sung die mathematische Optimierung zugrunde. Bereits anl{\"a}ßlich des IKM 1994 [1] hatte der Verfasser Gelegenheit, zusammenfassend {\"u}ber Ergebnisse bei der Anwendung der mathematischen Optimierung im Bereich der nichtlinearen Tragwerksanalyse zu berichten. Der vorliegende Beitrag, soll einen {\"U}berblick {\"u}ber seitdem untersuchte Problemkreise und dabei gewonnene Ergebnisse und Erfahrungen vermitteln. Bei der Anwendung der linearen und quadratischen Optimierung sind wegen der geforderten Linearit{\"a}t der Nebenbedingungen Vereinfachungen bei der Modellbildung des stahlbetonspezifischen Tragverhaltens unumg{\"a}nglich. Besonders betroffen sind die Ans{\"a}tze zur Beschreibungen des Materialverhaltens. Durch den Einsatz allgemeiner nichtlinearer mathematischer Optimierungsmethoden l{\"a}sst sich eine methodisch bedingte Linearisierung des Berechnungsmodells umgehen....}, subject = {Tragwerk}, language = {de} } @inproceedings{RaueTimmlerSchueler1997, author = {Raue, Erich and Timmler, Hans-Georg and Sch{\"u}ler, H.}, title = {Anwendung der mathematischen Optimierung bei der physikalisch und geometrisch nichtlinearen Analyse und Bemessung seismisch beanspruchter Tragwerke}, doi = {10.25643/bauhaus-universitaet.442}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4421}, year = {1997}, abstract = {Moderne Bemessungskonzepte f{\"u}r seismisch beanspruchte Hochbauten, wie die Methode der Kapazit{\"a}ts-bemessung, planen inelastisches Verhalten einzelner Bereiche der Konstruktion beim Entwurf bewußt ein, um so einen Teil der durch das Beben eingetragenen Energie als inelastische Form{\"a}nderungsarbeit zu absorbieren. Wird bei Akzeptanz inelastischen Verhaltens eine bestimmte Belastungsintensit{\"a}t, die als adaptive Grenzlast oder Einspiellast bezeichnet wird, {\"u}berschritten, kann es infolge zyklischer Einwirkungen zu einer unbe-grenzten Akkumulation inelastischer Deformationen kommen. Die adaptive Grenzlast stellt damit f{\"u}r zyklische Einwirkungen eine geeignete Kenngr{\"o}ße zur Bewertung der Tragwerksqualit{\"a}t dar, bei der neben der Sicherung des Gleichgewichts ein bestimmtes Sch{\"a}digungsniveau nicht {\"u}berschritten wird. Im vorliegenden Beitrag werden die Grundz{\"u}ge eines Bemessungs- und Nachweiskonzeptes f{\"u}r seismisch beanspruchte Stahlbetontragwerke, das unter Einbeziehung der Grundprinzipe der Kapazit{\"a}tsbemessung von einem einheitlichen Kriterium zur Beschreibung des Grenzzustandes der Tragf{\"a}higkeit auf der Basis der adaptive Grenzlast ausgeht, vorgestellt. Dabei ist die Absch{\"a}tzung der Verformungen notwendiger Bestandteil des Nachweis- bzw. Bemessungskonzeptes. Bei Druckgliedern ist die Ber{\"u}cksichtigung des Einflusses der Verformungen notwendiger Bestandteil des Bemessungskonzeptes. Entsprechende Erweiterungen der Berechnungsmodelle zur Ber{\"u}cksichtigung des Einflusses geometrisch nichtlinearer Effekte im Sinne einer Theorie II. Ordnung werden vorgestellt.}, subject = {Bauwerk}, language = {de} } @phdthesis{Semar2010, author = {Semar, Olivier}, title = {Anwendung der Perkolationstheorie zur Analyse des suffosiven Partikeltransportes}, doi = {10.25643/bauhaus-universitaet.1438}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20101124-15252}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2010}, abstract = {Die vorliegende Arbeit besch{\"a}ftigt sich mit der geometrischen Suffosionsbest{\"a}ndigkeit von Erdstoffen. Mit dem wahrscheinlichkeitstheoretischen Ansatz der Perkolationstheorie wurde ein analytisches Verfahren gew{\"a}hlt, mit dem suffosive Materialtransportprozesse modelliert und quantifiziert werden k{\"o}nnen. Mit dem verwendeten Perkolationsmodell wurde eine beliebige Porenstruktur eines realen Erdstoffes im 3-Dimensionalen modelliert. M{\"o}gliche Materialtransportprozesse innerhalb der modellierten Porenstruktur wurden anschließend simuliert. Allgemein g{\"u}ltige Gesetzm{\"a}ßigkeiten wurden hergeleitet und Grenzbedingungen formuliert. Diese sind vom Erdstoff unabh{\"a}ngig und beschreiben Zusammenh{\"a}nge zwischen Materialtransport und Porenstruktur. Anwendbar sind diese Ergebnisse auf homogene, isotrope und selbst{\"a}hnliche Erdstoffgef{\"u}ge. Aussagen {\"u}ber konkrete Erdstoffe k{\"o}nnen {\"u}ber die Transformationsmethode erfolgen. F{\"u}r die Verwendung der Transformationsmethode ist vorab die relevante Porenstruktur, d. h. die Porenengstellenverteilung, zu ermitteln.}, subject = {Perkolationstheorie}, language = {de} } @inproceedings{MostBucher2003, author = {Most, Thomas and Bucher, Christian}, title = {Application of the "fictious crack model" to meshless crack growth simulations}, doi = {10.25643/bauhaus-universitaet.335}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3359}, year = {2003}, abstract = {In this paper a meshless component is presented, which internally uses the common meshless interpolation technique >Moving Least Squares<. In contrast to usual meshless integration schemes like the cell quadrature and the nodal integration in this study integration zones with triangular geometry spanned by three nodes are used for 2D analysis. The boundary of the structure is defined by boundary nodes, which are similar to finite element nodes. By using the neighborhood relations of the integration zones an efficient search algorithm to detected the nodes in the influence of the integration points was developed. The components are directly coupled with finite elements by using a penalty method. An widely accepted model to describe the fracture behavior of concrete is the >Fictitious Crack Model< which is applied in this study, which differentiates between micro cracks and macro cracks, with and without force transmission over the crack surface, respectively. In this study the crack surface is discretized by node pairs in form of a polygon, which is part of the boundary. To apply the >Fictitious Crack Model< finite interface elements are included between the crack surface nodes. The determination of the maximum principal strain at the crack tip is done by introducing an influence area around the singularity. On a practical example it is shown that the included elements improve the model by the transmission of the surface forces during monotonic loading and by the representation of the contact forces of closed cracks during reverse loading.}, subject = {Bruchmechanik}, language = {en} } @inproceedings{Hartmann2004, author = {Hartmann, Ulrich C.}, title = {Collaboration in AEC Design : Web-enabling Applications using Peer-to-Peer Office Communicator}, doi = {10.25643/bauhaus-universitaet.138}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1386}, year = {2004}, abstract = {A market analysis conducted by Gartner Dataquest in August 2001 has shown the typical characteristics of the AEC design process. High volatility in membership of AEC design groups and members dispersed over several external offices is the common collaboration scenario. Membership is most times short lived, compared to the overall duration of the process. A technical solution has to take that into account by making joining and leaving a collaborative work group very easy. The modelling of roles of collaboration between group members must be based on a commonly understood principle like the publisher / subscriber model, where the individual that is responsible for the distribution of vital information is clear. Security issues and trust in the confidentiality of the system is a central concern for the acceptance of the system. Therefore, keeping the subset of data that will be published under the absolute control of the publisher is a must. This is not the case with server-based scenarios, sometimes even due to psychological reasons. A loosely bound Peer-to-Peer network offers advantages over a server-based solution, because of less administrative overhead and simple installation procedures. In a peer-to-peer environment, a publish/subscribe role model can be more easily implemented. The publish/subscribe model matches the way AEC processes are modelled in real world scenarios today, where legal proof of information exchange between external offices is of high importance. Workflow management systems for small to midsize companies of the AEC industry may adopt the peer-to-peer approach to collaboration in the future. Further investigations are being made on the research level (WINDS) by integrating the viewer and redlining application Collaborate! into a collaborative environment.}, subject = {Ingenieurbau}, language = {en} } @inproceedings{MilesJoitaBurnap2004, author = {Miles, John and Joita, Liviu and Burnap, Peter}, title = {Collaborative Engineering: Virtual Teams in a Grid Environment Supporting Consortia in the Construction Industry}, doi = {10.25643/bauhaus-universitaet.136}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1362}, year = {2004}, abstract = {In the AEC (Architecture / Engineering / Construction) industry a number of individuals and organisations collaborate and work jointly on a construction project. The resulting consortium has large pool of expertise and experience and can be defined as a Virtual Organisation (VO) formed for the duration of the project. VOs are electronically networked organisations where IT and web based communication technology play an important role in coordinating various activities of these organisations. This paper describes the design, development and implementation of a Grid enabled application called the Product Supplier Catalogue Database (PSCD) which supports collaborative working in consortia. As part of the Grid-enabling process, specialised metadata is being developed to enable PSCD to effectively utilise Grid middleware such as Globus and Java CoG toolkits. We also describe our experience whilst designing, developing and deploying the security service of the application using the Globus Security Interface (GSI).}, subject = {Ingenieurbau}, language = {en} } @inproceedings{Wittwer2003, author = {Wittwer, Christof}, title = {ColSim - Eine modulare Simulationsumgebung zur Entwicklung von Regelungsalgorithmen f{\"u}r Embedded Systems in Energieversorgungsanlagen}, doi = {10.25643/bauhaus-universitaet.380}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3803}, year = {2003}, abstract = {Am Fraunhofer ISE wurde in den letzten Jahren die Simulationsumgebung ColSim entwickelt, die sich speziell zur Untersuchung von Regelungssystemen in Geb{\"a}udeenergieversorgungssystemen eignet. Zielsetzung des Designs ist die Umsetzung des simulationsbasierten Regelungsentwurfs, der einen unmittelbaren Einsatz der Regelungsmodule auf sog. Enbedded Systems gestattet. Das Simulationswerkzeug zeichnet sich durch die modulare offene Struktur aus, die eine flexible Erweiterung erm{\"o}glicht (vgl. TRNSYS [1]). Die Implementierung erfolgte im genormten ANSI-C Code, der einen plattform- unabh{\"a}nigen Einsatz gew{\"a}hrleistet. Entwicklungsplattform stellt derzeit ein Linux Cluster dar, als Zielplattform wurden bisher sowohl eingebettete Industrie-PCs wie auch klassische Micro- controller Boards verwendet. Die Entwurfsmethode wird anhand einer Systemregelung f{\"u}r eine solarthermische Anlage mit 120m2 Kollektorfl{\"a}che (SolarThermie2000 Anlage) demonstriert, bei der ein vernetztes Regelungssystem mit Internet-Integration zum Einsatz kommt. Das Regelungssystem verf{\"u}gt seinerseits {\"u}ber ein Betriebssystem (schlankes embedded linux system), das die Kommunikation nach aussen gestattet. Das Regelungssystem vef{\"u}gt somit {\"u}ber Klima- bzw Strahlungsdaten, die f{\"u}r den Regelungsprozess von Bedeutung sind. Die externen Informationen k{\"o}nnen einerseits zur >Einsparung< von Sensorik genutzt werden, andererseits gestatten sie den Einsatz von pr{\"a}diktiver Regelungsmethodik, um den fossilen (Nachheiz-) Energieeinsatz zu minimieren. Mit Hilfe von simulationstechnischen Systemstudien kann ein adaptives Verhalten des Regelungssystems erprobt werden, das eine selbstst{\"a}ndige Strecken- identifikation realieren kann. Beispielsweise soll beim n{\"a}her beschriebenen solarthermischen System die Totzeit bestimmt werden, die sich infolge der Verrohrung zwischen Speicher und Entladegruppe ergibt. Der Betrieb der Entlade- pumpe wird einerseits in Abh{\"a}ngigkeit der Verf{\"u}gbarkeit des Pufferwassers erfolgen, andererseits in Abh{\"a}ngigkeit des erwarteten Zapfvolumens durch den Verbraucher. Die vernetzten Regelungssysteme, die auf Basis der Simulationsmodelle ent- wickelt werden, sollen k{\"u}nftig die gesamte Energieflußanalyse des Geb{\"a}udes realisieren, wobei eine transparente Darstellung des Systemverhaltens auf Basis einer Internet Visualisierung erfolgt. Der Betreiber und Nutzer wird unmittel- bar durch die Online Dienste (SMS,Email,Fax) {\"u}ber das (fehlerhafte) Anlagen- verhalten informiert. Gerade die sensitiven regenerativen Systeme neigen durch ihre Komplexit{\"a}t zu St{\"o}rungen, die oftmals nicht erkannt werden, weil die konventionellen Teilsysteme (z.B. Ergasbrenner) den Ausfall in der Regel >kompensieren<.}, subject = {Geb{\"a}ude}, language = {de} } @inproceedings{BaranskiBoron2003, author = {Baranski, Jacek and Boron, Jacek}, title = {Computer Modeling of the Joints for WGP Construction Systems}, doi = {10.25643/bauhaus-universitaet.293}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2935}, year = {2003}, abstract = {Poland is not situated in any seismic region of the earth, however there are still areas were underground mining is being conducted. In these areas, so-called 'paraseismic tremors', are very frequent phenomena. In the situation when a building examination is realized in order to define its safety, it is necessary to make a complete analysis, in which an influence of tremors should be included. To decide if a building is able to carry out any dynamic loads or not, it is necessary to compute its dynamic characteristics, i.e. natural frequencies. It is not possible using any standard techniques. After diagnosis a building in situ by an expert, computer techniques together with specialized software for dynamic, static, and strength analyses become a suitable tool. In this paper a special attention was paid to a typical twelve-store WGP (Wroclaw Great Plate) prefabricated building, concerning special type of joints. During dynamic actions these joints have a decisive influence on building's behavior. Paraseismic tremors are especially dangerous for these buildings and can be the reason of pre-failure states. It can be difficult and very expensive to prepare laboratory investigations of the part of a building or of a separate joint; therefore the computer modeling suitable to investigate behavior of such elements and whole buildings under different kinds of loads was used.}, subject = {Geb{\"a}ude}, language = {en} } @phdthesis{Hauschild2003, author = {Hauschild, Thomas}, title = {Computer Supported Cooperative Work-Applikationen in der Bauwerksplanung auf Basis einer integrierten Bauwerksmodellverwaltung}, doi = {10.25643/bauhaus-universitaet.64}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20040311-672}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2003}, abstract = {Gegenstand der vorliegenden Arbeit ist die Konzeption und prototypische Umsetzung von Techniken des Computer Supported Cooperative Work (CSCW) im Rahmen einer integrierten objektorientierten und dynamischen Bauwerksmodellverwaltung zur Unterst{\"u}tzung der Bauwerksplanung. Die Planung von Bauwerken ist durch einen hohen Grad an Arbeitsteiligkeit, aber auch durch eine schwache Strukturierung der ablaufenden Prozesse gekennzeichnet. Besonders durch den Unikatcharakter des Planungsgegenstands \'Bauwerk\' ergeben sich signifikante Unterschiede zum Entwurf anderer, durch Serienfertigung produzierter Industrieg{\"u}ter. Zunehmend wird die Planung von Bauwerken in Virtual Enterprises ausgef{\"u}hrt, die sich durch eine dynamische Organisationsstruktur, geographische Verteilung der Partner, schwer normierbare Informationsfl{\"u}sse und eine h{\"a}ufig stark heterogene informationstechnische Infrastruktur auszeichnen. Zur rechnerinternen Repr{\"a}sent! ation des Planungsgegenstands haben sich objektorientierte Bauwerksmodelle bew{\"a}hrt. Aufgrund der Ver{\"a}nderlichkeit der Bauwerke und deren rechnerinterner Repr{\"a}sentation im Laufe des Bauwerkslebenszyklus ist eine dynamische Anpassung der Modelle unumg{\"a}nglich. Derartige in Form von Taxonomien dargestellte dynamische Bauwerksmodellstrukturen k{\"o}nnen gemeinsam mit den in Instanzform vorliegenden konkreten Projektinformationen in entsprechenden Modellverwaltungssystemen (MVS) gehandhabt werden. Dabei wird aufgrund der Spezialisierung und Arbeitsteilung im Planungsprozess von einer inhaltlich verkn{\"u}pften Partialmodellstruktur, die r{\"a}umlich verteilt sein kann, ausgegangen. Die vorgeschlagenen Methoden zur Koordinierung der Teamarbeit in der Bauwerksplanung beruhen auf der Nutzung von CSCW-Techniken f{\"u}r \'Gemeinsame Informationsr{\"a}ume\' und \'Workgroup Computing\', die im Kontext der als Integrationsbasis fungierenden Modellverwaltungssysteme umgesetzt werden. Dazu werden die zur d! ynamischen Bauwerksmodellierung erforderlichen Metaebenenfunk! tionalit{\"a}ten sowie Ans{\"a}tze zur Implementierung von Modellverwaltungskernen systematisiert. Ebenso werden notwendige Basistechniken f{\"u}r die Realisierung von MVS untersucht und eine Architektur zur rollenspezifischen Pr{\"a}sentation dynamischer Modellinhalte vorgestellt. Da klassische Schichtenmodelle nicht auf die Verh{\"a}ltnisse in Virtual Enterprises angewendet werden k{\"o}nnen, wird eine physische Systemarchitektur mit einem zentralen Projektserver, Dom{\"a}nenservern und Dom{\"a}nenclients vorgestellt. Ebenso werden Techniken zur Sicherung des autorisierten Zugriffs sowie des Dokumentencharakters beschrieben. Zur Unterst{\"u}tzung der asynchronen Phasen der Kooperation wird der gemeinsame Informationsraum durch Mappingtechniken zur Propagation und Notifikation von {\"A}nderungsdaten bez{\"u}glich relevanter Modellinformationen erg{\"a}nzt. Zur Unterst{\"u}tzung synchroner Phasen werden Techniken zur Schaffung eines gemeinsamen Kontexts durch relaxierte WYSIWIS-Pr{\"a}sentationen auf Basis der Modellinformationen! verbunden mit Telepresence-Techniken vorgestellt. Weiterhin werden Methoden zur Sicherung der Group-Awareness f{\"u}r alle Kooperationsphasen betrachtet.}, subject = {Computer Supported Cooperative Work}, language = {de} } @article{GuerlebeckLegatiukNilssonetal., author = {G{\"u}rlebeck, Klaus and Legatiuk, Dmitrii and Nilsson, Henrik and Smarsly, Kay}, title = {Conceptual modelling: Towards detecting modelling errors in engineering applications}, series = {Mathematical Methods in Applied Sciences}, journal = {Mathematical Methods in Applied Sciences}, doi = {10.1002/mma.5934}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200110-40614}, pages = {1 -- 10}, abstract = {Rapid advancements of modern technologies put high demands on mathematical modelling of engineering systems. Typically, systems are no longer "simple" objects, but rather coupled systems involving multiphysics phenomena, the modelling of which involves coupling of models that describe different phenomena. After constructing a mathematical model, it is essential to analyse the correctness of the coupled models and to detect modelling errors compromising the final modelling result. Broadly, there are two classes of modelling errors: (a) errors related to abstract modelling, eg, conceptual errors concerning the coherence of a model as a whole and (b) errors related to concrete modelling or instance modelling, eg, questions of approximation quality and implementation. Instance modelling errors, on the one hand, are relatively well understood. Abstract modelling errors, on the other, are not appropriately addressed by modern modelling methodologies. The aim of this paper is to initiate a discussion on abstract approaches and their usability for mathematical modelling of engineering systems with the goal of making it possible to catch conceptual modelling errors early and automatically by computer assistant tools. To that end, we argue that it is necessary to identify and employ suitable mathematical abstractions to capture an accurate conceptual description of the process of modelling engineering systems.}, subject = {Angewandte Mathematik}, language = {en} } @article{LegatiukWeiszPatrault, author = {Legatiuk, Dmitrii and Weisz-Patrault, Daniel}, title = {Coupling of Complex Function Theory and Finite Element Method for Crack Propagation Through Energetic Formulation: Conformal Mapping Approach and Reduction to a Riemann-Hilbert Problem}, series = {Computational Methods and Function Theory}, volume = {2021}, journal = {Computational Methods and Function Theory}, publisher = {Springer}, address = {Heidelberg}, doi = {10.1007/s40315-021-00403-7}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20210805-44763}, pages = {1 -- 23}, abstract = {In this paper we present a theoretical background for a coupled analytical-numerical approach to model a crack propagation process in two-dimensional bounded domains. The goal of the coupled analytical-numerical approach is to obtain the correct solution behaviour near the crack tip by help of the analytical solution constructed by using tools of complex function theory and couple it continuously with the finite element solution in the region far from the singularity. In this way, crack propagation could be modelled without using remeshing. Possible directions of crack growth can be calculated through the minimization of the total energy composed of the potential energy and the dissipated energy based on the energy release rate. Within this setting, an analytical solution of a mixed boundary value problem based on complex analysis and conformal mapping techniques is presented in a circular region containing an arbitrary crack path. More precisely, the linear elastic problem is transformed into a Riemann-Hilbert problem in the unit disk for holomorphic functions. Utilising advantages of the analytical solution in the region near the crack tip, the total energy could be evaluated within short computation times for various crack kink angles and lengths leading to a potentially efficient way of computing the minimization procedure. To this end, the paper presents a general strategy of the new coupled approach for crack propagation modelling. Additionally, we also discuss obstacles in the way of practical realisation of this strategy.}, subject = {Angewandte Mathematik}, language = {en} } @inproceedings{PetzoldWenderDonathetal.2003, author = {Petzold, Frank and Wender, Katrin and Donath, Dirk and Weferling, Ulrich}, title = {Das Bauwerk als Informationscontainer in den fr{\"u}hen Phasen der Bauaufnahme - Ausgangspunkt f{\"u}r die Projektentwicklung und Entwurfsformulierung}, doi = {10.25643/bauhaus-universitaet.347}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3479}, year = {2003}, abstract = {Die digitale Unterst{\"u}tzung der Planungsprozesse ist ein aktueller Forschungs- und Arbeitsschwerpunkt der Professur Informatik in der Architektur (InfAR) und der Juniorprofessur Architekturinformatik der Fakult{\"a}t Architektur an der Bauhaus-Universit{\"a}t Weimar. Verankert in dem DFG Sonderforschungsbereich 524 >Werkzeuge und Konstruktionen f{\"u}r die Revitalisierung von Bauwerken< entstehen Konzepte und Prototypen f{\"u}r eine fachlich orientierte Planungsunterst{\"u}tzung. In dem Beitrag wird ein Konzept und prototypische Realisierung f{\"u}r die durchg{\"a}ngige Unterst{\"u}tzung des gesamten Bauaufnahmeprozesses f{\"u}r Altbausubstanz vorgestellt und diskutiert. Der Fokus liegt auf der fr{\"u}he Phase in der Bauaufnahme als ein Baustein in einer gesamtheitlichen IT-gest{\"u}tzen Planungsumgebung eingegangen. Durch gezielte Aufnahme planungsrelevanter Parameter und Auswertung hinsichtlich Wirtschaftlichkeit und Wiederverwendbarkeit bzw. der Varianten{\"u}berpr{\"u}fung von Nutungskonzepten, werden gerade in dieser Phase wesentliche Entscheidungen f{\"u}r eine kosteng{\"u}nstige Planung getroffen werden. In der Ver{\"o}ffentlichung wird der Fokus auf folgende Punkte gesetzt: - Strukturierung und Aufnahme der Informationen w{\"a}hrend der Erstbegehung - Skizzenhafte Abbildung als Basis f{\"u}r die Formulierung erster Entwurfsintensionen/ Variantenuntersuchungen - Navigations- und Informationsumgebung - gezielte Auswertungsm{\"o}glichkeiten (bspw. Wirtschaftlichkeitsberechnung, Wiederverwendung von Bauteilen, Kalkulation von Abrissmengen)}, subject = {Geb{\"a}ude}, language = {de} } @inproceedings{LaabsPahl1997, author = {Laabs, Andreas and Pahl, Peter Jan}, title = {Das Beobachterkonzept zum Erhalt der Konsistenz in Datenmodellen}, doi = {10.25643/bauhaus-universitaet.431}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4310}, year = {1997}, abstract = {Die Aufgaben des Bauingenieurwesens sind dadurch gepr{\"a}gt, daß sowohl die Planung als auch die Ausf{\"u}hrung von Bauwerken h{\"a}ufigen {\"A}nderungen unterliegen. Beschreibt man das Verhalten der Bauwerke und den Bauprozeß im Computer mit Modellen, so {\"a}ndern sich Umfang und Struktur der Modelle als Folge der {\"A}nderung in Planung und Ausf{\"u}hrung. Diesen Vorgang nennt man Dynamisierung des Modells. Die Dynamisierung f{\"u}hrt zu Ver{\"a}nderungen und Inkonsistenzen in den Modellen der Anwendungen. Die Aktualisierung und Abstimmung von Beziehungen innerhalb eines Modells sowie die Sicherung der Konsistenz der Modelle untereinander sind daher von zentraler Bedeutung f{\"u}r die L{\"o}sung von Bauingenieuraufgaben. Seit den letzten 10 Jahren wird die objektorientierte Methode in der Modellierung f{\"u}r Anwendungen im Bauingenieurwesen intensiv entwickelt und eingesetzt. Es hat sich gezeigt, daß die Anwendung dieser Methode in wichtigen Bereichen der Modellierung zu Verbesserungen f{\"u}hrt. Gleichzeitig hat sich aber auch herausgestellt, daß die f{\"u}r das Bauingenieurwesen wichtigen Aspekte der Aktualisierung und der Konsistenz nicht zweckm{\"a}ßig beschreibbar sind. In diesem Beitrag wird eine einfache Modelliermethode in ihrem Konzept und ihrer Realisierung gezeigt, mit der sich die Aktualisierung von Objekten und Modellen sowie die Sicherstellung der Konsistenz in Systemen des Bauingenieurwesens bearbeiten lassen.}, subject = {Bauwerk}, language = {de} } @phdthesis{Bubner2006, author = {Bubner, Andr{\´e}}, title = {Datenmodelle zur Bearbeitung von Ingenieuraufgaben am Beispiel von Wohnh{\"a}usern in Stahlbauweise}, doi = {10.25643/bauhaus-universitaet.808}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20070423-8580}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2006}, abstract = {Modelle bilden die Grundlage der Planung. Sie repr{\"a}sentieren die zur Bearbeitung erforderlichen Eigenschaften eines Bauwerks in einer an die spezifische Aufgabe angepassten Form. Zwischen den verschiedenen zur Abbildung des Bauwerks eingesetzten Modellen bestehen fachliche Zusammenh{\"a}nge bez{\"u}glich der darin abgebildeten Aspekte. Diese Abh{\"a}ngigkeiten werden in der praktischen Planungsbearbeitung gegenw{\"a}rtig auf Grundlage von Erfahrungswerten, normativen Vorgaben und vereinfachenden Annahmen ber{\"u}cksichtigt. Die detailliertere Modellierung von Bauwerkseigenschaften f{\"u}hrt zu einer engeren Verzahnung der verschiedenen Modelle. Um eine fachliche Inselbildung zu vermeiden, ist eine entsprechend angepasste Abbildung der zwischen den einzelnen Modellen bestehenden Beziehungen erforderlich. Mit den steigenden Anspr{\"u}chen an eine Bearbeitung von Ingenieuraufgaben gewinnt eine {\"u}ber den Zweck der Bereitstellung ausgew{\"a}hlter Informationen zum Bauwerk und der Unterst{\"u}tzung eines Datenaustauschs zwischen verschiedenen Fachplanern hinausgehende datentechnische Abbildung an Bedeutung. Dies setzt eine Diskussion der Anforderungen an eine solche Beschreibung aus fachlicher Sicht voraus. Die Untersuchung der fachlichen Anforderungen wird am Beispiel von Wohnh{\"a}usern in Stahlbauweise gef{\"u}hrt.}, subject = {Modellierung}, language = {de} } @inproceedings{LaehrBletzinger2004, author = {L{\"a}hr, Andr{\´e} and Bletzinger, Kai-Uwe}, title = {Design of an Analysis Environment for Planning Decision Support}, doi = {10.25643/bauhaus-universitaet.1370}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1370}, year = {2004}, abstract = {In this contribution, the design of an analysis environment is presented, that supports an analyst to come to a decision within a gradual collaborative planning process. An analyst represents a project manager, planner or any other person, involved in the planning process. Today, planning processes are managed by several geographically distributed planners and project managers. Thus, complexity of such a process rises even more. Prediction of consequences of many planning decisions is not possible, in particular since assessment of a planning advance is not trivial. There have to be considered several viewpoints, that depend on individual perceptions. In the following, methods are presented to realize planning decision support.}, subject = {Ingenieurbau}, language = {en} } @inproceedings{YahiaouiHensenSoethout2004, author = {Yahiaoui, Azzedine and Hensen, Jan and Soethout, Luc}, title = {Developing CORBA-based distributed control and building performance environments by run-time coupling}, doi = {10.25643/bauhaus-universitaet.134}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1347}, year = {2004}, abstract = {Communication software and distributed applications for control and building performance simulation software must be reliable, efficient, flexible, and reusable. This paper reports on progress of a project, which aims to achieve better integrated building and systems control modeling in building performance simulation by run-time coupling of distributed computer programs. These requirements motivate the use of the Common Object Request Broker Architecture (CORBA), which offers sufficient advantage than communication within simple abstraction. However, set up highly available applications with CORBA is hard. Neither control modeling software nor building performance environments have simple interface with CORBA objects. Therefore, this paper describes an architectural solution to distributed control and building performance software tools with CORBA objects. Then, it explains how much the developement of CORBA based distributed building control simulation applications is difficult. The paper finishes by giving some recommendations.}, subject = {Ingenieurbau}, language = {en} } @article{FischerSteinhage1997, author = {Fischer, A. and Steinhage, V.}, title = {Ein modellbasiertes Konzept zur st{\"a}dteplanerischen Kartierung durch digitale Bildanalyse}, doi = {10.25643/bauhaus-universitaet.487}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4870}, year = {1997}, abstract = {There is an increasing need for 3D building extraction from aerial images for various applications such astown planning, environmental- and property-related studies. Aerial images usually reveal on one hand a certain amount of information not relevant for the given task of building extraction like vegetation, cars etc. On the other hand there is a loss of relevant information due to occlusions, low contrasts or disadvantageous perspectives. Therefore a promising concept for automated building reconstruction must incorporate a suffciantly complete model of the objects of interest. We propose a model-based approach to 3D building extraction from aerial images which reveals a tight coupling between a generic 3D object model and an explicit 2D image model. The generic object model employes domain specific volumetric primitives (i. e. building part models) and combination schemes. To cover the gap between 3D object models and 2D image data the image model is employed to predict the projective building appearences in aerial images. We present a strategy for a model-based building extraction based on the recognition-by-components principle and show first experimental results derived from international test sets}, subject = {Stadtplanung}, language = {de} } @inproceedings{KieselEngelsVoelker, author = {Kiesel, Gerd and Engels, Merit and V{\"o}lker, Conrad}, title = {Energetische Transformation im l{\"a}ndlichen Raum - Aufbau eines prozessorientierten Entwicklungs- und Moderationsmodells}, series = {Schriftenreihe des Fachgebiets Bauphysik/Energetische Geb{\"a}udeoptimierung}, booktitle = {Schriftenreihe des Fachgebiets Bauphysik/Energetische Geb{\"a}udeoptimierung}, editor = {Kornadt, Oliver and Carrigan, Svenja and Hofmann, Markus and V{\"o}lker, Conrad}, publisher = {Eigenverlag Technische Universit{\"a}t Kaiserslautern}, address = {Kaiserslautern}, isbn = {978-3-95974-176-7}, issn = {2363-8206}, doi = {10.25643/bauhaus-universitaet.4656}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220617-46566}, pages = {3}, abstract = {Kleine Kommunen im l{\"a}ndlichen Raum sind aufgrund ihrer oft eingeschr{\"a}nkten personellen und finanziellen Kapazit{\"a}ten bisher eher sporadisch in den Themenfeldern Energieeffizienz und Erneuerbare Energien aktiv. Immer wieder stellt sich daher Frage, wie die Klimaschutzstrategien des Bundes und der L{\"a}nder dort mit dem verf{\"u}gbaren Personal kosteng{\"u}nstig realisierbar sind. Vor diesem Hintergrund wird ein Werkzeug entwickelt, mit dessen Hilfe der aktive Einstieg in diese Thematik mit geringen Aufwand und {\"u}berwiegend barrierefrei m{\"o}glich ist. Der Aufbau eines prozessorientierten Entwicklungs- und Moderationsmodells zur Erprobung und Umsetzung bezahlbarer Handlungsoptionen f{\"u}r Energieeinsparungen und effizienten Energieeinsatz im {\"u}berwiegend l{\"a}ndlichen gepr{\"a}gten Raum ist der Schwerpunkt der Softwarel{\"o}sung. Kommunen werden mit deren Hilfe in die Lage versetzt, in die notwendigen Prozesse der Energie- und W{\"a}rmewende einzusteigen. Dabei soll der modulare Aufbau die regul{\"a}ren Schritte notwendiger (integrierter) Planungsprozesse nicht vollst{\"a}ndig ersetzen. Vielmehr k{\"o}nnen innerhalb der Online-Anwendung - {\"u}berwiegend automatisiert - konkrete Maßnahmenvorschl{\"a}ge erstellt werden, die ein solides Fundament der k{\"u}nftigen energetischen Entwicklung der Kommunen darstellen. F{\"u}r eine gezielte Validierung der Ergebnisse und der Ableitung potentieller Maßnahmen werden f{\"u}r die Erprobung Modellkommunen in Th{\"u}ringen, Bayern und Hessen als Reallabore einbezogen. Das Tool steht bisher zun{\"a}chst nur den beteiligten Modellkommunen zur Verf{\"u}gung. Die entwickelte Softwarel{\"o}sung soll k{\"u}nftig Schritt f{\"u}r Schritt allen interessierten Kommunen mit diversen Hilfsmitteln und einer Vielzahl anderer praktischer Bestandteile zur Verf{\"u}gung gestellt werden.}, subject = {Modellierung}, language = {de} } @phdthesis{Goebel, author = {G{\"o}bel, Luise}, title = {Experimental and semi-analytical multiscale approaches for the characterization of the elastic and viscoelastic behavior of polymer-modified cement-based materials}, publisher = {Bauhaus-Universit{\"a}tsverlag}, address = {Weimar}, isbn = {978-3-95773-269-9}, doi = {10.25643/bauhaus-universitaet.3827}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20181211-38279}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {259}, abstract = {Polymer-modified cement concrete (PCC) is a heterogeneous building material with a hierarchically organized microstructure. Therefore, continuum micromechanics-based multiscale models represent a promising method to estimate the mechanical properties. By means of a bottom-up approach, homogenized properties at the macroscopic scale are derived considering microstructural characteristics. The extension of existing multiscale models for the application to PCC is the main objective of this work. For that, cross-scale experimental studies are required. Both macroscopic and microscopic mechanical tests are performed to characterize the elastic and viscoelastic properties of different PCC. The comparison between experiment and model prediction illustrates the success of the modeling approach.}, subject = {Elastizit{\"a}tsmodul}, language = {en} } @article{StaubFrench2004, author = {Staub-French, Sheryl}, title = {Feature-based Product Modeling for Building Construction}, doi = {10.25643/bauhaus-universitaet.233}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2331}, year = {2004}, abstract = {Current building product models explicitly represent components, attributes of components, and relationships between components. These designer-focused product models, however, do not represent many of the design conditions that are important for construction, such as component similarity, uniformity, and penetrations. Current design and construction tools offer limited support for detecting these construction-specific design conditions. This paper describes the ontology we developed using the manufacturing concept of features to represent the design conditions that are important for construction. The feature ontology provides the blueprint for the additions and changes needed to transform a standard product model into a constructionspecific product model. The ontology formalizes three classes of features, defines the attributes and functions of each feature type, and represents the relationships between features explicitly. The descriptive semantics of the ontology allows practitioners to represent their varied preferences for naming features, specifying features that result from component intersections and the similarity of components, and grouping features that affect a specific construction domain. A software prototype that implements the ontology enables practitioners to transform designer-focused product models into feature-based product models that represent the construction perspective.}, subject = {Produktmodell}, language = {en} } @inproceedings{BergerGraeffWeinberg1997, author = {Berger, Hans and Graeff-Weinberg, K.}, title = {FEM-Detailuntersuchungen an Tragwerken unter Einsatz von pNh-{\"U}bergangselementen}, doi = {10.25643/bauhaus-universitaet.426}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4267}, year = {1997}, abstract = {Detailuntersuchungen an Tragwerken f{\"u}hren bei FE-Berechnungen immer wieder auf das Problem einer geeigneten Netzgestaltung. W{\"a}hrend in weiten Bereichen ein grobes Netz ausreicht, muß an kritischen Stellen ein sehr feines Netz gew{\"a}hlt werden, um gerade dort hinreichend genaue Ergebnisse zu erhalten. Bei der Realisierung lokaler Netzverdichtungen stellt die Gestaltung des {\"U}bergangs vom groben zum feinen Netz das Hauptproblem dar. Im Beitrag wird hierzu eine Familie von FE-{\"U}bergangselementen vorgestellt, mit denen sich eine voll-kompatible Kopplung von wenigen großen Elementen mit vielen kleinen Elementen bereits {\"u}ber nur eine Stufe erzielen l{\"a}ßt. Diese neu entwickelten sogenannten pNh-Elemente erm{\"o}glichen an einer oder mehreren Seiten den Anschluß von N kleineren Elementen (Elementseiten f{\"u}r h-Verfeinerung). Das wird durch N st{\"u}ckweise definierte Ansatzfunktionen an den entsprechenden Seiten erreicht, wobei die Teilung nicht {\"a}quidistant sein braucht. Dar{\"u}ber hinaus ist es m{\"o}glich, Elemente unterschiedlichen Polynomgrades p an den Standardseiten und den Verfeinerungsseiten anzuschließen. Der praktische Einsatz der {\"U}bergangselemente setzt geeignete automatische oder halbautomatische Netzgeneratoren voraus, die diese Elemente einbeziehen. Im Rahmen einer substrukturorientierten Modellierung l{\"a}ßt sich dies besonders g{\"u}nstig realisieren. Im Beitrag wird gezeigt, wie durch Zerlegung des Gesamtmodells in Bereiche mit grobem Netz, mit {\"U}bergangsnetz und mit feinem Netz, eine effektive Generierung der Netzverdichtungen zu erreichen ist. An einem praktischen Beispiel aus dem Bauingenieurwesen werden die Vorteile des vorgestellten {\"U}bergangselementkonzeptes umfassend demonstriert.}, subject = {Tragwerk}, language = {de} } @article{WehnerSteinmannHuebler1997, author = {Wehner, R. and Steinmann, Frank and H{\"u}bler, Reinhard}, title = {FLEXOB - Entwicklungstool f{\"u}r dynamische, modellbasierte CAD-Systeme}, doi = {10.25643/bauhaus-universitaet.457}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4571}, year = {1997}, abstract = {Objektorientierte Modellierungstechniken werden gegenw{\"a}rtig vor allem Entwicklern von CAD-Systemen angeboten. Sie erzeugen {\"u}ber die Schritte OO-Modellanalyse und OO-Softwaredesign OO-Programme, die mit ihrer Compilation das durch den Softwareingenieur gefundene Modell festschreiben. Generell, aber insbesondere im Bauwerksdesign, ist dieses Vorgehen unbefriedigend, da hier eine Normung von Modellen nicht gelingt, der Entwurfsprozeß vergleichsweise lang ist und eine Kooperation von Ingenieurgewerken mit verschiedenen Modelldom{\"a}nen die Regel sind. Dar{\"u}ber hinaus weisen die Modelle in fr{\"u}hen Phasen ein hohes Maß an Unsch{\"a}rfe und Abstraktion auf. CAD-Tools, die diese Phasen unterst{\"u}tzen, ben{\"o}tigen deshalb: statt eines genormten Produktmodells ein einheitliches, kognitiv begr{\"u}ndetes Modellstrukturierungsparadigma, f{\"u}r das mit der Objektorientierung eine m{\"o}gliche Auspr{\"a}gung gegeben ist, ein explizites, verf{\"u}gbares Dom{\"a}nenmodell zur fortw{\"a}hrenden Interpretation von Bauwerksmodellen, deskriptive Elemente, die die Interpretation von Objekten und Attributen erleichtern, ein Konzept zur Behandlung von Unsch{\"a}rfe und Abstraktion. Hieraus ergeben sich f{\"u}r die Entwicklung von CAD-Systemen folgende Forderungen : Explizite Verf{\"u}gbarkeit von Klassenobjekten und deren Erzeugung und Ver{\"a}nderung zur Laufzeit, Vererbung auf Klassen- und Instanzniveau, Erweiterte Attributkonzepte (Facetten), Unterst{\"u}tzung der Aggregation als einer wesentlichen Modellstrukturierungsrelation, Verf{\"u}gbarkeit von OO-Schnittstellen zum Aufbau von CAD-Systemen aus Tools einerseits, sowie zur Trennung von Modellverwaltung und Modellrepr{\"a}sentation andererseits. Als ein herausragendes Merkmal des Objektorientierten Paradigmas wird die Anwendungsn{\"a}he genannt, da Erscheinungen der behandelten Dom{\"a}ne sich analog in Modellen und Programmen wiederfinden (sollen). Unter der Grundannahme, daß dieses Paradigma auch durch den Anwender zur Erstellung seiner Modellwelten verwendet wird, will FLEXOB eine homogene Umgebung schaffen, die die Modellwelt des Softwareingenieurs zu Analysezwecken dem Anwender zur Verf{\"u}gung stellt und die die Erweiterung dieser Modellwelt auf deskriptivem Niveau erm{\"o}glicht. Das Tool FLEXOB und einige wesentliche Implementationsdetails werden im Beitrag vorgestellt. Es handelt sich bei diesem Tools um eine C++ Klassenbibliothek, die entweder als Objektmodul oder als Windows-DLL verwendet werden kann. Aspekte des Nutzungsregimes solch flexibler Modellverwaltungen werden im Beitrag ebenfalls angespochen.}, subject = {CAD}, language = {de} } @phdthesis{Haefner2006, author = {H{\"a}fner, Stefan}, title = {Grid-based procedures for the mechanical analysis of heterogeneous solids}, doi = {10.25643/bauhaus-universitaet.858}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20070830-9185}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2006}, abstract = {The importance of modern simulation methods in the mechanical analysis of heterogeneous solids is presented in detail. Thereby the problem is noted that even for small bodies the required high-resolution analysis reaches the limits of today's computational power, in terms of memory demand as well as acceptable computational effort. A further problem is that frequently the accuracy of geometrical modelling of heterogeneous bodies is inadequate. The present work introduces a systematic combination and adaption of grid-based methods for achieving an essentially higher resolution in the numerical analysis of heterogeneous solids. Grid-based methods are as well primely suited for developing efficient and numerically stable algorithms for flexible geometrical modeling. A key aspect is the uniform data management for a grid, which can be utilized to reduce the effort and complexity of almost all concerned methods. A new finite element program, called Mulgrido, was just developed to realize this concept consistently and to test the proposed methods. Several disadvantages which generally result from grid discretizations are selectively corrected by modified methods. The present work is structured into a geometrical model, a mechanical model and a numerical model. The geometrical model includes digital image-based modeling and in particular several methods for the theory-based generation of inclusion-matrix models. Essential contributions refer to variable shape, size distribution, separation checks and placement procedures of inclusions. The mechanical model prepares the fundamentals of continuum mechanics, homogenization and damage modeling for the following numerical methods. The first topic of the numerical model introduces to a special version of B-spline finite elements. These finite elements are entirely variable in the order k of B-splines. For homogeneous bodies this means that the approximation quality can arbitrarily be scaled. In addition, the multiphase finite element concept in combination with transition zones along material interfaces yields a valuable solution for heterogeneous bodies. As the formulation is element-based, the storage of a global stiffness matrix is superseded such that the memory demand can essentially be reduced. This is possible in combination with iterative solver methods which represent the second topic of the numerical model. Here, the focus lies on multigrid methods where the number of required operations to solve a linear equation system only increases linearly with problem size. Moreover, for badly conditioned problems quite an essential improvement is achieved by preconditioning. The third part of the numerical model discusses certain aspects of damage simulation which are closely related to the proposed grid discretization. The strong efficiency of the linear analysis can be maintained for damage simulation. This is achieved by a damage-controlled sequentially linear iteration scheme. Finally a study on the effective material behavior of heterogeneous bodies is presented. Especially the influence of inclusion shapes is examined. By means of altogether more than one hundred thousand random geometrical arrangements, the effective material behavior is statistically analyzed and assessed.}, subject = {B-Spline}, language = {en} } @inproceedings{Walukiewicz2003, author = {Walukiewicz, Henryk}, title = {Identification of Structural Models as a Problem of Group Representation Theory}, doi = {10.25643/bauhaus-universitaet.372}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3725}, year = {2003}, abstract = {It has been shown that symmetries of moment functions of stochastic processes play an important role in identification of systems. They provide the group-theoretic method of choice of the model structure and model parameters. In the first stage the group-theoretic analysis of some fundamental concepts of stochastic dynamics: stochastic processes and functional series of Volterra-Wiener type has been undertaken. The analysis of group representations of the moment functions of order m for stochastic processes is the basic, original concept of the work. The following groups: symmetric Sm, special affine SAff(m), general linear GL(n, R), GL(n,C) and their subgroups play the main role in the models. In the second stage the informational entropy has been introduced as a measure of the randomness in the identified models. The group-theoretic approach underlines the unity of the nonlinear system identification and leads to useful engineering results in the range of the second-order (stochastic) theory.}, subject = {Bauwerk}, language = {en} } @inproceedings{GebbekenBaumhauerIonita2004, author = {Gebbeken, Norbert and Baumhauer, Andreas and Ionita, Mihai}, title = {Increasing the Reliability and Performance through Automatization and Parallel Working}, doi = {10.25643/bauhaus-universitaet.139}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1397}, year = {2004}, abstract = {Re-examination of the behaviour of structures can be necessary due to deterioration or changes in the traffic situation during their lifetime. The Finite Element Method (FEM) is widely used in order to accomplish numerical analysis. Considering the development of computer performance, more detailed FEM models can be analyzed, even on site, with mobile computers. To compensate the increasing amount of data needed for the model input, measures need to be taken to save time, by distributing the work. In order to provide consistency to the model, fedback data must be checked upon reception. A local wireless computer network of ultra-portable devices linked together with a computer can provide the coordination necessary for efficient parallel working. Based on a digital model consisting of all data gathered, structural modelling and numerical analysis are performed automatically. Thus, the user is released from the work that can be automatized and the time needed for the overall analysis of a structure is decreased.}, subject = {Ingenieurbau}, language = {en} } @inproceedings{HauschildBorrmannHuebler2004, author = {Hauschild, Thomas and Borrmann, Andr{\´e} and H{\"u}bler, Reinhard}, title = {Integration of Constraints into Digital Building Models for Cooperative Planning Processes}, doi = {10.25643/bauhaus-universitaet.177}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1775}, year = {2004}, abstract = {The uniqueness and the long life cycle of buildings imply a dynamically modifiable building model. The technological foundation for the management of digital building models, a dynamic model management system (MMS), developed by our research group, allows to explicitly access and to modify the object model of the stored planning data. In this paper, the integration of constraints in digital building models will be shown. Constraints are conditions, which apply to the instances of domain model classes, and are defined by the user at runtime of the information system. For the expression of constraints, the Constraint Modelling Language (CML) has been developed and will be described in this paper. CML is a powerful, intuitively usable object-oriented language, which allows the expression of constraints at a high semantic level. A constrained-enabled MMS can verify, whether an instance fulfils the applying constraints. To ensure flexibility, the evaluation of constraints is not implicitly performed by the systems, but explicitly initiated by the user. A classification of constraint types and example usage scenarios are given.}, subject = {Architektur}, language = {en} } @inproceedings{HartmannMeissnerRueppel2004, author = {Hartmann, Dietrich and Meißner, Udo F. and Rueppel, Uwe}, title = {Integration of Productmodel Databases into Multi-Agent Systems}, doi = {10.25643/bauhaus-universitaet.141}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1410}, year = {2004}, abstract = {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.}, subject = {Ingenieurbau}, language = {en} } @phdthesis{Willenbacher2002, author = {Willenbacher, Heiko}, title = {Interaktive verkn{\"u}pfungsbasierte Bauwerksmodellierung als Integrationsplattform f{\"u}r den Bauwerkslebenszyklus}, doi = {10.25643/bauhaus-universitaet.30}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20040216-328}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2002}, abstract = {Den Gegenstand der Dissertation bilden die Konzeption und die exemplarische Realisierung eines verkn{\"u}pfungsbasierten Bauwerksmodellierungsansatzes zur Schaffung einer integrierenden Arbeits- und Planungsumgebung f{\"u}r den Lebenszyklus von Bauwerken. Die Basis der Integration bildet ein deklarativ ausgerichteter Bauwerksmodellverbund bestehend aus abstrahierten, dom{\"a}nenspezifischen Partialmodellen. Auf Grund der de facto existierenden Dynamik im Bauwerkslebenszyklus werden sowohl der Bauwerksmodellverbund als auch die einzelnen Partialmodelle dynamisch modifizierbar konzipiert und auf Basis spezieller Modellverwaltungssysteme technisch realisiert. Die Verst{\"a}ndigung innerhalb der vorgeschlagenen Gesamtbauwerksmodellarchitektur basiert auf anwenderspezifisch zu erstellenden Verkn{\"u}pfungen zwischen den Partialmodellen und wird im Sinne einer hybriden Modellarchitektur durch eine zentrale, die Verkn{\"u}pfungen verwaltende Komponente koordiniert. Zur Verwaltung und Abarbeitung der Verkn{\"u}pfungen wird der Einsatz von Softwareagenten im Rahmen eines Multiagentensystems vorgeschlagen und diskutiert.}, subject = {Bauwerk}, language = {de} } @article{Rudnicki1997, author = {Rudnicki, Andrzej}, title = {Investigation by Computer Simulation - some aspect of transportation service reliability in urban public transport}, doi = {10.25643/bauhaus-universitaet.482}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4829}, year = {1997}, abstract = {Essence of service unreliability on account of irregularity has been given. The reasons of occurance of overcrowded vehicles have been listed. The factor of service unreliability on account of irregularity has been determined. It is probability of the event, that the passenger finds departing vehicle fully filled, i.e. when all places seating and standing are occupied or condition of the travel, which would be not acceptable for passenger. Large dispersion of headways (i.e. irregularity) increases probability of such situations. To calculate the mentioned factor, the computer simulation was used. Both, passenger arrivals and vehicle operation have been modelled as stochastic interacted processes. Distributions of headways and passenger arrivals have been fixed by statistical methods. The >maximal capacity< of a vehicle has been determined. The set of parameters values for simulation runs has been given. The transformed results of computer simulation are series of nomographs for determination of a factor value. They were prepared for many types of trams and city buses, but only one nomograph has been presented. Difficulties in verification of model were discussed. Recommendations for rational utilisation level of public transport means capacity in the condition of randomness of passenger arrivals and disturbances in vehicle operation have been proposed. The other possibilities of service unreliability have been mentioned. General conclusions have been given}, subject = {{\"O}ffentlicher Personennahverkehr}, language = {en} } @article{KreibichPirothSeifertetal., author = {Kreibich, H. and Piroth, K. and Seifert, I. and Maiwald, Holger and Kunert, U. and Schwarz, Jochen and Merz, B. and Thieken, A. H.}, title = {Is flow velocity a significant parameter in flood damage modelling?}, series = {Natural Hazards and Earth System Science}, journal = {Natural Hazards and Earth System Science}, doi = {10.25643/bauhaus-universitaet.3145}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170425-31455}, pages = {1679 -- 1692}, abstract = {Flow velocity is generally presumed to influence flood damage. However, this influence is hardly quantified and virtually no damage models take it into account. Therefore, the influences of flow velocity, water depth and combinations of these two impact parameters on various types of flood damage were investigated in five communities affected by the Elbe catchment flood in Germany in 2002. 2-D hydraulic models with high to medium spatial resolutions were used to calculate the impact parameters at the sites in which damage occurred. A significant influence of flow velocity on structural damage, particularly on roads, could be shown in contrast to a minor influence on monetary losses and business interruption. Forecasts of structural damage to road infrastructure should be based on flow velocity alone. The energy head is suggested as a suitable flood impact parameter for reliable forecasting of structural damage to residential buildings above a critical impact level of 2m of energy head or water depth. However, general consideration of flow velocity in flood damage modelling, particularly for estimating monetary loss, cannot be recommended.}, subject = {Str{\"o}mungsgeschwindigkeit}, language = {en} } @inproceedings{Weitzmann2003, author = {Weitzmann, R{\"u}diger}, title = {Limit state design of hybrid structures with meshless methods using mathematical optimization}, doi = {10.25643/bauhaus-universitaet.6}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-67}, year = {2003}, abstract = {The revitalization of existing structures belongs to the frequently tasks in urban reconstruction processes. The adaptation for new requirements will commonly affect substantial changes in the general configuration of structures. The resulting revitalized structures are characterized by a hybrid design, where old and new, identical or diverse materials and members will be coupled in different ways. In the planning stage the treatment of these systems leads to application of complex and hybrid mechanical models respectively. High performance numerical instruments have to be applied for solving not only analysis but also targeted design problems. Because of the hybrid character of mechanical models in revitalization planning processes the use of hybrid technologies is advantageous. In this paper mixed domain technique will be used for connecting EFG and FE. The models derived will be adopted for design purposes of non-linear loaded hybrid structures. The investigations show a good adaptability of the meshless methods to the design of hybrid structures by using optimization strategies. With this method the advantages of both finite element and meshless methods can be utilized most suitable. With the property of a minimum amount of unknowns by maintaining an adequate quality of the results the application of mixed finite element and meshless methods is a promising alternative to traditional methods in structural analysis and optimization.}, subject = {Geb{\"a}ude}, language = {de} } @inproceedings{GrigrievaLymarenko2003, author = {Grigrieva, Polina and Lymarenko, Yulia}, title = {Mathematical modeling of nonlinear effects for vibrodiagnostics of fatigue cracks}, doi = {10.25643/bauhaus-universitaet.291}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2917}, year = {2003}, abstract = {The vibration control of complicated mechanical structures is impossible without proper mathematical models that allow to have a true apprehension of events occurring in structural member before the starting of the experiment and correct the diagnostic experiment in case of need. An approach that implies using of a discrete model reflecting all required features of a prototype system and permitting of an effective analytical and numerical investigation is proposed in the work. At first a discrete model of a bladed disk with flaw is considered. Taking into account the symmetry of the structure by utilization of mathematical tools of group presentation theory the number of degrees of freedom of the system is diminished. Small damage of the disk is regarded as perturbation of structure symmetry. The distinction of vibration characteristics such as natural frequencies and mode shapes of damaged and undamaged systems is determined theoretically with the help of perturbation theory and can be used as an effective diagnostic criterion of a small-scale damage of the structure. In the second part of the work a non-linear two-mass model of an acoustic emission in a damaged structure is proposed. On basis of the numerical integration of the nonlinear differential equations and expansion of the derived solution into a Fourier series free and forced vibrations of the model are investigated. It is shown that proposed model reflects all characteristic properties of vibrations of damaged structures: reduction of natural frequency, sub- and super-resonances, acoustic effects.}, subject = {Nichtlineare Mechanik}, language = {en} } @article{Legatiuk, author = {Legatiuk, Dmitrii}, title = {Mathematical Modelling by Help of Category Theory: Models and Relations between Them}, series = {mathematics}, volume = {2021}, journal = {mathematics}, number = {volume 9, issue 16, article 1946}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/math9161946}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20210817-44844}, pages = {17}, abstract = {The growing complexity of modern practical problems puts high demand on mathematical modelling. Given that various models can be used for modelling one physical phenomenon, the role of model comparison and model choice is becoming particularly important. Methods for model comparison and model choice typically used in practical applications nowadays are computationbased, and thus time consuming and computationally costly. Therefore, it is necessary to develop other approaches to working abstractly, i.e., without computations, with mathematical models. An abstract description of mathematical models can be achieved by the help of abstract mathematics, implying formalisation of models and relations between them. In this paper, a category theory-based approach to mathematical modelling is proposed. In this way, mathematical models are formalised in the language of categories, relations between the models are formally defined and several practically relevant properties are introduced on the level of categories. Finally, an illustrative example is presented, underlying how the category-theory based approach can be used in practice. Further, all constructions presented in this paper are also discussed from a modelling point of view by making explicit the link to concrete modelling scenarios.}, subject = {Kategorientheorie}, language = {en} } @inproceedings{PopovaDatchevaIankov2003, author = {Popova, E. D. and Datcheva, Maria and Iankov, Roumen}, title = {Mechanical Models with Interval Parameters}, doi = {10.25643/bauhaus-universitaet.348}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3482}, year = {2003}, abstract = {In this paper we consider modelling of composite material with inclusions where the elastic material properties of both matrix and inclusions are uncertain and vary within prescribed bounds. Such mechanical systems, involving interval uncertainties and modelled by finite element method, can be described by parameter dependent systems of linear interval equations and process variables depending on the system solution. A newly developed hybrid interval approach for solving parametric interval linear systems is applied to the considered model and the results are compared to other interval methods. The hybrid approach provides very sharp bounds for the process variables - element strains and stresses. The sources for overestimation when dealing with interval computations are demonstrated. Based on the element strains and stresses, we introduce a definition for the values of nodal strains and stresses by using a set-theoretic approach.}, subject = {Verbundwerkstoff}, language = {en} } @inproceedings{RueppelMeissnerGutzke2003, author = {R{\"u}ppel, Uwe and Meißner, Iris and Gutzke, Thomas}, title = {Mobile Computing in der Grundwasserbewirtschaftung}, doi = {10.25643/bauhaus-universitaet.354}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3547}, year = {2003}, abstract = {Die Bewirtschaftung von Grundwasser umfasst zum einen die Nutzungserfordernisse und Versorgungsbed{\"u}rfnisse und zum andern den Schutz des Grundwassers als Bestandteil des Naturhaushaltes. Die Verwendung von Informations- und Kommunikationsmethoden zur numerischen Grundwassermodellierung und zur Verwaltung von großfl{\"a}chigen qualitativen und quantitativen Grundwasserinformationen er{\"o}ffnen die M{\"o}glichkeit einer nachhaltigen wasserwirtschaftlichen Planung sowie einer gezielten Steuerung der Auswirkungen von Grundwasserentnahmen und -versickerungen. Im Rahmen des Pilotprojektes Grundwasser-Online im Hessischen Ried (www.grundwasser-online.de) wurden gezielt die Arbeitsabl{\"a}ufe bei der Erfassung der Daten zur Grundwasserbewirtschaftung sowie der anschließenden Verarbeitung analysiert, bewertet und software-technisch umgesetzt. Ein wichtiger Aspekt dabei ist die Datenerfassung an den r{\"a}umlich verteilten Grundwassermessstellen. Der vorliegende Beitrag zeigt auf, wie mobile EDV Ger{\"a}te mit einer geeigneten Software die Arbeitsabl{\"a}ufe beim Einsatz vor Ort effizienter gestalten und die Einhaltung der Messvorgaben unterst{\"u}tzen k{\"o}nnen. Durch die Minimierung von Fehlerquellen kann dabei eine Qualit{\"a}tsverbesserung des Datenbestandes erreicht werden. Es wird ein Konzept zur mobilen Erfassung von Grundwasserdaten unter Verwendung von GPS-Positionsdaten und Plausibilit{\"a}tspr{\"u}fungen vorgestellt. Die Technologien und Herausforderungen bei der prototypischen Umsetzung werden aufgezeigt.}, subject = {Grundwasser}, language = {de} } @article{PiskunovMarchuk1997, author = {Piskunov, V. G. and Marchuk, A. V.}, title = {Model of stressed-strained State of Multilayer Masses with regard for Non-Ideal Contact of Layers}, doi = {10.25643/bauhaus-universitaet.542}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5427}, year = {1997}, abstract = {Thus, mathematical model stressed- strained of a condition of layered masses is constructed. The model has high accuracy. It allows to simulate slippery contact of layers without friction. Thus not the order of permitting system of the equations is increased, and at its realization the method of fenite elements does not increase quantity of required degrees freedom. The differential operators included in system the equations are similar known in the classical theory of shells. It facilitates construction of a finite element. Presence in system of the differential equations of derivative of external forces allows to use her for the decision of contact problems with a stain of contact commensurable with thickness of a masses.}, subject = {Geschichtetes Medium}, language = {en} } @inproceedings{Huhnt2000, author = {Huhnt, Wolfgang}, title = {Modellierung der Prozesse als Basis der Informationssysteme f{\"u}r Bauunternehmen}, doi = {10.25643/bauhaus-universitaet.596}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5969}, year = {2000}, abstract = {Die fachlichen Grundlagen der Aufgaben, die in einem Bauunternehmen zu bearbeiten sind, wurden in verschiedenen Disziplinen entwickelt. Maßgeblich waren der Baubetrieb und die Betriebswirtschaftslehre. Die parallele Entwicklung hat jedoch dazu gef{\"u}hrt, dass grundlegende Begriff und Verfahren zwischen den Disziplinen nicht aufeinander abgestimmt sind. Die verschiedenen Aufgaben beeinflussen jedoch einander. Innerhalb der jeweiligen Disziplin wurden Informationssysteme entwickelt, mit denen sich die Aufgaben aus der jeweiligen Disziplin bearbeiten lassen. Zur Verbindung der "verschiedenen Welten" existieren zwar ausgew{\"a}hlte Schnittstellen, eine durchg{\"a}ngige verteilte Bearbeitung der verschiedenen Aufgaben wird jedoch noch nicht umfassend unterst{\"u}tzt. Im vorliegenden Beitrag wird ein Vorgehen vorgestellt, auf dessen Grundlage eine verteilte Bearbeitung der fachgebiets{\"u}bergreifenden Aufgaben erfolgen kann. Das Vorgehen beruht auf der Modellierung der Prozesse sowie der zur Bearbeitung der als Bestandteil der Prozesse spezifizierten Aufgaben ben{\"o}tigten Informationen. Dieses Modell wird auf der Grundlage der Mengenlehre mit einem entsprechenden Werkzeug aufgebaut. Die Spezifikation der Informationen wird genutzt, um Datenbankschemata zu generieren, die Spezifikation der Aufgaben wird genutzt, um Werkzeuge zur Bearbeitung zu identifizieren. Diese Werkzeuge sind in Java als Applets implementiert und k{\"o}nnen {\"u}ber entsprechende Treiber auf die Datenbanken zugreifen. Das Prozessmodell wird in einem n{\"a}chsten Schritt erweitert. Personen werden eingef{\"u}hrt. Diesen Personen werden Aufgaben zugewiesen, deren Bearbeitung sie ausf{\"u}hren sollen. Auf der Grundlage des erweiterten Prozessmodells werden die Applets, die eine Person ben{\"o}tigt, auf einer entsprechenden Internet-Seite zusammengestellt. Damit kann projektspezifisch ein Informationssystem zusammengestellt werden, das eine verteilte Bearbeitung der verschiedenartigen Aufgaben unterst{\"u}tzt.}, subject = {Baubetrieb}, language = {de} } @article{Dudek1997, author = {Dudek, Mariusz}, title = {Modellierung der Verkehrsmittelwahl}, doi = {10.25643/bauhaus-universitaet.481}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4817}, year = {1997}, abstract = {Die Zielstellung der Modal­Split­Betrachtungen l{\"a}uft darauf hinaus, Entscheidungs-kriterien zu erarbeiten, nach denen die einzelnen Personen ihre Verkehrsmittel ausw{\"a}hlen. In dieser Ver{\"o}ffentlichung wurden alle drei Gruppen der Modelle (klassische, verhaltensorientierte und der Analyse) der Verkehrsaufteilung kurz charakterisiert. Dann wurden vier ausgew{\"a}hlte Modelle genauer beschrieben. Zum Schluß wird das Modell der Verkehrsmittelwahl dargestellt , das f{\"u}r die Untersuchung der Verkehrsaufteilung in Krakau verwendet wurde .}, subject = {Verkehrsmittelwahl}, language = {de} } @inproceedings{LaemmerMeissnerRuben2003, author = {L{\"a}mmer, Lutz and Meißner, Udo F. and Ruben, Jochen}, title = {Modellierung von Baugrund-Tragwerk-Systemen f{\"u}r die parallele numerische Simulation unter Ber{\"u}cksichtigung dynamischer Aspekte}, doi = {10.25643/bauhaus-universitaet.327}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3276}, year = {2003}, abstract = {Bei der Gr{\"u}ndung von schweren Bauwerken (z.B. Hochh{\"a}usern auf Gr{\"u}ndungsplatten und pf{\"a}hlen) wird der Lastabtrag in den Baugrund durch eine starke Interaktion zwischen Bauwerk und Baugrund bestimmt. Der Baugrund kann ph{\"a}nomenologisch als Mehrphasenkontinuum beschrieben werden, bei dem die Phasen Feststoff, Fl{\"u}ssigkeit und Gas in mechanische Wechselwirkung treten. Die Wechselwirkung zwischen der Deformation des Feststoffes und der Str{\"o}mung des Porenwassers spielt unter der Lasteinwirkung des Bauwerks und unter dynamischer Erregung eine zentrale Rolle. Bei komplexen Gr{\"u}ndungsverh{\"a}ltnissen k{\"o}nnen die Deformations- und Spannungszust{\"a}nde realit{\"a}tsnah nur durch dreidimensionale Modelle erfasst werden. Je nach Baufortschritt stellen sich die Probleme dabei unterschiedlich dar. Der vorliegende Beitrag besch{\"a}ftigt sich mit der f{\"u}r die mit der Simulation mit der Methode der finiten Elemente notwendigen Modellierung und der rechnergest{\"u}tzten Netzgenerierung f{\"u}r die Baugrund-Tragwerk-Strukturen. Bei komplexen dreidimensionalen Gr{\"u}ndungskonstruktionen ist eine solche rechnergest{\"u}tzte Diskretisierung mit finiten Elementen zweckm{\"a}ßig, die das geotechnische System und dessen Randbedingungen und Lasten umfassend beschreiben und verwalten kann. Daf{\"u}r werden geeignete Software-Werkzeuge vorgestellt, mit denen sich dreidimensionale, zeitabh{\"a}ngige Systeme modellieren und diskretisieren lassen. Die Kontaktproblematik zwischen Baugrund und Tragwerk und die Besonderheiten des Mehrphasenkontinuums stellen besondere Anspr{\"u}che an die Diskretisierung. Zudem werden Methoden vorgestellt, die das akkumulierte Gr{\"u}ndungsmodell, das sich {\"u}ber den Bauablauf ergibt, verwalten und die verschiedenen Bauzust{\"a}nde in einem dynamischen Modell bereitstellen.}, subject = {Boden-Bauwerk-Wechselwirkung}, language = {de} } @phdthesis{Salavati, author = {Salavati, Mohammad}, title = {Multi-Scale Modeling of Mechanical and Electrochemical Properties of 1D and 2D Nanomaterials, Application in Battery Energy Storage Systems}, doi = {10.25643/bauhaus-universitaet.4183}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200623-41830}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {166}, abstract = {Material properties play a critical role in durable products manufacturing. Estimation of the precise characteristics in different scales requires complex and expensive experimental measurements. Potentially, computational methods can provide a platform to determine the fundamental properties before the final experiment. Multi-scale computational modeling leads to the modeling of the various time, and length scales include nano, micro, meso, and macro scales. These scales can be modeled separately or in correlation with coarser scales. Depend on the interested scales modeling, the right selection of multi-scale methods leads to reliable results and affordable computational cost. The present dissertation deals with the problems in various length and time scales using computational methods include density functional theory (DFT), molecular mechanics (MM), molecular dynamics (MD), and finite element (FE) methods. Physical and chemical interactions in lower scales determine the coarser scale properties. Particles interaction modeling and exploring fundamental properties are significant challenges of computational science. Downscale modelings need more computational effort due to a large number of interacted atoms/particles. To deal with this problem and bring up a fine-scale (nano) as a coarse-scale (macro) problem, we extended an atomic-continuum framework. The discrete atomic models solve as a continuum problem using the computationally efficient FE method. MM or force field method based on a set of assumptions approximates a solution on the atomic scale. In this method, atoms and bonds model as a harmonic oscillator with a system of mass and springs. The negative gradient of the potential energy equal to the forces on each atom. In this way, each bond's total potential energy includes bonded, and non-bonded energies are simulated as equivalent structural strain energies. Finally, the chemical nature of the atomic bond is modeled as a piezoelectric beam element that solves by the FE method. Exploring novel materials with unique properties is a demand for various industrial applications. During the last decade, many two-dimensional (2D) materials have been synthesized and shown outstanding properties. Investigation of the probable defects during the formation/fabrication process and studying their strength under severe service life are the critical tasks to explore performance prospects. We studied various defects include nano crack, notch, and point vacancy (Stone-Wales defect) defects employing MD analysis. Classical MD has been used to simulate a considerable amount of molecules at micro-, and meso- scales. Pristine and defective nanosheet structures considered under the uniaxial tensile loading at various temperatures using open-source LAMMPS codes. The results were visualized with the open-source software of OVITO and VMD. Quantum based first principle calculations have been conducting at electronic scales and known as the most accurate Ab initio methods. However, they are computationally expensive to apply for large systems. We used density functional theory (DFT) to estimate the mechanical and electrochemical response of the 2D materials. Many-body Schr{\"o}dinger's equation describes the motion and interactions of the solid-state particles. Solid describes as a system of positive nuclei and negative electrons, all electromagnetically interacting with each other, where the wave function theory describes the quantum state of the set of particles. However, dealing with the 3N coordinates of the electrons, nuclei, and N coordinates of the electrons spin components makes the governing equation unsolvable for just a few interacted atoms. Some assumptions and theories like Born Oppenheimer and Hartree-Fock mean-field and Hohenberg-Kohn theories are needed to treat with this equation. First, Born Oppenheimer approximation reduces it to the only electronic coordinates. Then Kohn and Sham, based on Hartree-Fock and Hohenberg-Kohn theories, assumed an equivalent fictitious non-interacting electrons system as an electron density functional such that their ground state energies are equal to a set of interacting electrons. Exchange-correlation energy functionals are responsible for satisfying the equivalency between both systems. The exact form of the exchange-correlation functional is not known. However, there are widely used methods to derive functionals like local density approximation (LDA), Generalized gradient approximation (GGA), and hybrid functionals (e.g., B3LYP). In our study, DFT performed using VASP codes within the GGA/PBE approximation, and visualization/post-processing of the results realized via open-source software of VESTA. The extensive DFT calculations are conducted 2D nanomaterials prospects as anode/cathode electrode materials for batteries. Metal-ion batteries' performance strongly depends on the design of novel electrode material. Two-dimensional (2D) materials have developed a remarkable interest in using as an electrode in battery cells due to their excellent properties. Desirable battery energy storage systems (BESS) must satisfy the high energy density, safe operation, and efficient production costs. Batteries have been using in electronic devices and provide a solution to the environmental issues and store the discontinuous energies generated from renewable wind or solar power plants. Therefore, exploring optimal electrode materials can improve storage capacity and charging/discharging rates, leading to the design of advanced batteries. Our results in multiple scales highlight not only the proposed and employed methods' efficiencies but also promising prospect of recently synthesized nanomaterials and their applications as an anode material. In this way, first, a novel approach developed for the modeling of the 1D nanotube as a continuum piezoelectric beam element. The results converged and matched closely with those from experiments and other more complex models. Then mechanical properties of nanosheets estimated and the failure mechanisms results provide a useful guide for further use in prospect applications. Our results indicated a comprehensive and useful vision concerning the mechanical properties of nanosheets with/without defects. Finally, mechanical and electrochemical properties of the several 2D nanomaterials are explored for the first time—their application performance as an anode material illustrates high potentials in manufacturing super-stretchable and ultrahigh-capacity battery energy storage systems (BESS). Our results exhibited better performance in comparison to the available commercial anode materials.}, subject = {Batterie}, language = {en} } @inproceedings{EslimyIsfahanyPegels2004, author = {Eslimy-Isfahany, S. H. R. and Pegels, Georg}, title = {Net-distributed Co-operation Including Developing Countries, Practical Case Study - Iran}, doi = {10.25643/bauhaus-universitaet.142}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1421}, year = {2004}, abstract = {The scientific transfer of key technology features to developing countries, together with adequate competence, localisation and adaptation, is the primary purpose of the proposed investigation. It is evident that introducing high-level CAD design and detailing will improve the planning process in developing countries. Successful utilization of applied information technology for the planning process, however, depends on the user-interface of individual software. Therefore, to open the great opportunity embedded in CAD software for clients globally, the language and character-set barrier of traditional user-interfaces must be overcome. A proposal for a research program is given here to address such issue in favour of global civil engineering.}, subject = {Ingenieurbau}, language = {en} } @inproceedings{SchleyMejstrikHolz2004, author = {Schley, Frank and Mejstrik, Marcus and Holz, K.-Peter}, title = {Network Based Co-operation Platform for Geotechnical Engineering}, doi = {10.25643/bauhaus-universitaet.143}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1431}, year = {2004}, abstract = {This paper describes an approach to support co-operation of experts in heterogeneous geotechnical engineering project environments during both regular execution and handling of exceptional situations. A co-operation platform is introduced which is based on a generalized information model mapping key information about the construction project, the construction process as well as the organization structure. Several tools are provided to operate the information model in a network based environment.}, subject = {Ingenieurbau}, language = {en} } @inproceedings{MeissnerRueppelTheiss2004, author = {Meißner, Udo F. and Rueppel, Uwe and Theiss, Mirko}, title = {Network-Based Fire Engineering Supported by Agents}, doi = {10.25643/bauhaus-universitaet.144}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1447}, year = {2004}, abstract = {Building design in Civil Engineering is characterized by the cooperation of experts in multiple disciplines. Close cooperation of engineers in different fields is the basis of high product quality, short development periods and a minimum of investment costs. For each building the engineers have to create a new fire engineering model. The consistent realization of the fire engineering model in all details has high demands on communication, collaboration and building models. Thereby, to preserve the related design models consistent to each other and compatible with the rules of fire engineering is a complex task. In addition, regulations and guidelines vary according to the building location, so the knowledge base must be integrated dynamically into the planning process. This contribution covers the integration of engineers and design models into a cooperation network on the basis of mobile agents. The distributed models of architectural design, structural planning and fire engineering are supported. These models are implemented as XML-based models which can be accessed by mobile agents for information retrieval and for processing tasks. Agents are provided to all planners, they are enabled to check up the distributed design models with the knowledge base of the fire protection regulations,. With the use of such an agent each planner is supported to check up his planning for accordance with the fire protection requirements. The fire-engineering-agent analyzes the design and detects inconsistencies by processing fire protection requirements and design model facts in a rule-based expert system. The possibility to check the planning information at an early state in the sense of compatibility to the fire protection regulations enables a comprehensive diagnosis of the design and the reduction of planning errors.}, subject = {Ingenieurbau}, language = {en} } @inproceedings{WeferlingDonathPetzoldetal.2003, author = {Weferling, Ulrich and Donath, Dirk and Petzold, Frank and Thurow, Torsten}, title = {Neue Techniken in der Bestandserfassung}, doi = {10.25643/bauhaus-universitaet.373}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3734}, year = {2003}, abstract = {Die digitale Unterst{\"u}tzung der Planungsprozesse ist ein aktueller Forschungs- und Arbeitsschwerpunkt der Professur Informatik in der Architektur (InfAR) und der Juniorprofessur Architekturinformatik der Fakult{\"a}t Architektur an der Bauhaus-Universit{\"a}t Weimar. Verankert in dem DFG Sonderforschungsbereich 524 >Werkzeuge und Konstruktionen f{\"u}r die Revitalisierung von Bauwerken< entstehen Konzepte und Prototypen f{\"u}r eine fachlich orientierte Planungsunterst{\"u}tzung. Als ein Teilaspekt wird in diesem Beitrag gezeigt, wie das Handaufmaß unter Einsatz modernen taktiler Erfassungsmethoden eine ganz neue Bedeutung f{\"u}r die Datenerfassung gewinnen kann. Das Potenzial der verschiedenen Verfahren zur Koordinatenbestimmung mit taktilen Werkzeugen wird evaluiert. Daraus wird eine Strategie entwickelt, die f{\"u}r die unterschiedlichen Notwendigkeiten im Planungsfortschritt den optimierten Einsatz der taktilen Erfassung in Kombination mit klassischen Erfassungsmethoden aufzeigt. Die Realisierbarkeit eines derartigen Konzeptes wird durch Fallstudien und m{\"o}gliche Ablaufszenarien f{\"u}r einzelne Verfahren nachgewiesen. Durch die Integration taktiler Messverfahren in die Bestandserfassung kann erreicht werden, dass - relevante (Geometrie-) Informationen in ein umfassendes Bauwerksmodell integriert werden k{\"o}nnen, - die Bauaufnahme wieder im direkten Kontakt zum Bauaufnahmeobjekt erfolgen kann und - die Verfahren so einfach und leicht von allen Beteiligten eingesetzt werden k{\"o}nnen, um die Bauaufnahme und die Planung wieder miteinander zu verzahnen.}, subject = {Geb{\"a}ude}, language = {de} } @inproceedings{HahnWeitzmann2003, author = {Hahn, Stephan and Weitzmann, R{\"u}diger}, title = {Nichtlineare Analyse von hybriden Konstruktionen unter Verwendung von selektiv gekoppelten Tragwerks- und Querschnittsmodellen}, doi = {10.25643/bauhaus-universitaet.302}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3026}, year = {2003}, abstract = {Bei der Untersuchung hybrider Strukturen kann eine Kopplung von Modellen unterschiedlicher Modellebenen vorteilhaft sein. Durch selektive Kopplung von Tragwerks- und Querschnittsmodellen in ausgew{\"a}hlten Bereichen der Konstruktion kann z.B. eine Verbesserung der Abbildungsgenauigkeit erzielt werden. Dadurch werden erweiterte Aussagen {\"u}ber das Querschnittstragverhalten in extrem beanspruchten Teilen des Tragwerks bei optionaler Skalierbarkeit des Modellumfangs m{\"o}glich. Im Beitrag werden ausgew{\"a}hlte Varianten der Modellbildung gegen{\"u}bergestellt und bewertet. Hierbei werden Aspekte der physikalischen Nichtlinearit{\"a}t von hybriden Konstruktionen insbesondere von Stahlbetonkonstruktionen ber{\"u}cksichtigt. Die Einbeziehung von Verfahren der mathematischen Optimierung in die Berechnungsstrategie erm{\"o}glicht die L{\"o}sung der zugrunde liegenden nichtlinearen Problemstellungen unter Vorgabe von Bemessungszielen und unter Beachtung von Grenzzustandsbedingungen.}, subject = {Tragwerk}, language = {de} } @inproceedings{vanRooyenOlivier2004, author = {van Rooyen, G.C. and Olivier, A. H.}, title = {Notes on structural analysis in a distributed collaboratory}, doi = {10.25643/bauhaus-universitaet.145}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1451}, year = {2004}, abstract = {The worldwide growth of communication networks and associated technologies provide the basic infrastructure for new ways of executing the engineering process. Collaboration amongst team members seperated in time and location is of particular importance. Two broad themes can be recognized in research pertaining to distributed collaboration. One theme focusses on the technical and technological aspects of distributed work, while the other emphasises human aspects thereof. The case of finite element structural analysis in a distributed collaboratory is examined in this paper. An approach is taken which has its roots in human aspects of the structural analysis task. Based on experience of how structural engineers currently approach and execute this task while utilising standard software designed for use on local workstations only, criteria are stated for a software architechture that could support collaborative structural analysis. Aspects of a pilot application and the results of qualitative performance measurements are discussed.}, subject = {Ingenieurbau}, language = {en} }