@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} } @inproceedings{XieIssaO'Brien2004, author = {Xie, Haiyan and Issa, Raja and O'Brien, William}, title = {Structure of a Formal User Model for Construction Information Retrieval}, doi = {10.25643/bauhaus-universitaet.129}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1296}, year = {2004}, abstract = {Information science researchers and developers have spent many years addressing the problem of retrieving the exact information needed and using it for analysis purposes. In informationseeking dialogues, the user, i.e. construction project manager or supplier, often asks questions about specific aspects of the tasks they want to perform. But most of the time it is difficult for the software systems to unambiguously understand their overall intentions. The existence of information tunnels (Tannenbaum 2002) aggravates this phenomenon. This study includes a detailed case study of the material management process in the construction industry. Based on this case study, the structure of a formal user model for information retrieval in construction management is proposed. This prototype user model will be incorporated into the system design for construction information management and retrieval. This information retrieval system is a user-centered product based on the development of a user configurable visitor mechanism for managing and retrieving project information without worrying too much about the underlying data structure of the database system. An executable UML model combined with OODB is used to reduce the ambiguity in the user's intentions and to achieve user satisfaction.}, subject = {Bauwerk}, language = {en} } @inproceedings{WudtkeWerner, author = {Wudtke, Idna and Werner, Frank}, title = {MODELLING OF MATERIAL PHENOMENA OF STEEL IN CONSTITUTIVE RELATIONS IN CONTEXT OF WELDING}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, issn = {1611-4086}, doi = {10.25643/bauhaus-universitaet.2903}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170314-29032}, pages = {16}, abstract = {The application of partly decoupled approach by means of continuum mechanics facilitates the calculation of structural responses due to welding. The numerical results demonstrate the ability of a qualitative prediction of welded connections. As it is intended to integrate the local effects of a joint in structural analysis of steel constructions, it is necessary to meet higher approaches towards quality. The wide array of material parameters are presented, which are affecting the thermal, metallurgical and mechanical behavior, and which have to be identified. For that purpose further investigations are necessary to analyze the sensitivity of the models towards different material properties. The experimental determination of every material parameter is not possible due to the extraordinary laborious efforts needed. Besides that, experimentally identified parameters can be applied only for the tested steel quality for measured temperature-time regimes. For that reason alternative approaches for identification of material parameters, such as optimization strategies, have to be applied. After a definition of material parameters a quantitative prediction of welded connections will also be possible. Numerical results show the effect of phase transformation, activated by welding process, on residual stress state. As these phenomena occur in local areas in the range of crystal and grain sizes, the description of microscopic phenomena and their propagation on a macroscopic level due to approaches of homogenization might be expedient. Nevertheless, one should bear in mind, the increasing number of material parameters as well as the complexity of their experimental determination. Thus the microscopic approach should always be investigated under the scope of ability and efficiency of a required prediction. Under certain circumstances a step backwards, adopting a phenomenological approach, also can be beneficial.}, subject = {Angewandte Informatik}, language = {en} } @inproceedings{Wudtke, author = {Wudtke, Idna}, title = {CONSTITUTIVE MODELING OF CRYSTALLINE MATERIALS WITH TEXTURE CHARACTERISTICS}, series = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar}, booktitle = {Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar}, editor = {G{\"u}rlebeck, Klaus and Lahmer, Tom and Werner, Frank}, organization = {Bauhaus-Universit{\"a}t Weimar}, issn = {1611-4086}, doi = {10.25643/bauhaus-universitaet.2791}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170314-27910}, pages = {9}, abstract = {The analysis of the response of complex structural systems requires the description of the material constitutive relations by means of an appropriate material model. The level of abstraction of such model may strongly affect the quality of the prognosis of the whole structure. In context to this fact, it is necessary to describe the material in a convenient sense as exact but as simple as possible. All material phenomena of crystalline materials e.g. steel, affecting the behavior of the structure, rely on physical effects which are interacting over spatial scales from subatomic to macroscopic range. Nevertheless, if the material is microscopically heterogenic, it might be appropriate to use phenomenological models for the purpose of civil engineering. Although constantly applied, these models are insufficient for steel materials with microscopic characteristics such as texture, typically occurring in hot rolled steel members or heat affected zones of welded joints. Hence, texture is manifested in crystalline materials as a regular crystallographic structure and crystallite orientation, influencing macroscopic material properties. The analysis of structural response of material with texture (e.g. rolled steel or heat affected zone of a welded joint) obliges the extension of the phenomenological material description of macroscopic scale by means of microscopic information. This paper introduces an enrichment approach for material models based on a hierarchical multiscale methodology. This has been done by describing the grain texture on a mesoscopic scale and coupling it with macroscopic constitutive relations by means of homogenization. Due to a variety of available homogenization methods, the question of an assessment of coupling quality arises. The applicability of the method and the effect of the coupling method on the reliability of the response are presented on an example.}, subject = {Angewandte Informatik}, language = {en} } @inproceedings{WoywodeWeikert2001, author = {Woywode, Norbert and Weikert, Fritz}, title = {Qualit{\"a}ts- und Sicherheitsprobleme in der Schweißtechnik}, doi = {10.25643/bauhaus-universitaet.400}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4005}, year = {2001}, abstract = {Im Beitrag wird belegt, dass es viele Gemeinsamkeiten von Qualit{\"a}tsverletzungen und Verst{\"o}ßen gegen die Sicherheitsvorschriften gibt. An Hand einiger Beispiele wird gezeigt, wie sich durch - Schwachstellen in der technischen und technologischen Vorbereitung, - M{\"a}ngel im Gesundheits-, Arbeits- und Brandschutz, - ungen{\"u}gende Qualifikation sowie subjektives Fehlverhalten von Arbeitern, - Material-, Fertigungs- und Konstruktionsfehler Unf{\"a}lle, Schadensf{\"a}lle, Gesundheitssch{\"a}den und Br{\"a}nde insbesondere beim Schweißen ereignet haben und damit die aufgezeigten Zusammenh{\"a}nge best{\"a}tigen.}, subject = {Arbeitsschutz}, language = {de} } @inproceedings{WoszczynaKaminskiMajetal., author = {Woszczyna, Anna and Kaminski, Mieczysław and Maj, Marek and Ubysz, Andrzej}, title = {ANALYSING THE INFLUENCE OF THE REINFORCED CONCRETE CHIMNEY GEOMETRY CHANGES ON THE STRESSES IN THE CHIMNEY SHAFT}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.3038}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-30388}, pages = {7}, abstract = {Analysis of the reinforced concrete chimney geometry changes and their influence on the stresses in the chimney mantle was made. All the changes were introduced to a model chimney and compared. Relations between the stresses in the mantle of the chimney and the deformations determined by the change of the chimney's vertical axis geometry were investigated. The vertical axis of chimney was described by linear function (corresponding to the real rotation of the chimney together with the foundation), and by parabolic function (corresponding to the real dislocation of the chimney under the influence of the horizontal forces - wind). The positive stress pattern in the concrete as well as the negative stress pattern in the reinforcing steel have been presented. The two cases were compared. Analysis of the stress changes in the chimney mantle depending on the modification in the thickness of the mantle (the thickness of the chimney mantle was altered in the linear or the abrupt way) was carried out. The relation between the stresses and the chimney's diameter change from the bottom to the top of the chimney was investigated. All the analyses were conducted by means of a specially developed computer program created in Mathematica environment. The program makes it also possible to control calculations and to visualize the results of the calculations at every stage of the calculation process.}, subject = {Architektur }, language = {en} } @inproceedings{WolkowiczRuthStahr, author = {Wolkowicz, Christian and Ruth, J{\"u}rgen and Stahr, Alexander}, title = {TOOL TO CHECK TOPOLOGY AND GEOMETRY FOR SPATIAL STRUCTURES ON BASIS OF THE EXTENDED MAXWELL'S RULE}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, doi = {10.25643/bauhaus-universitaet.3037}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170327-30370}, pages = {8}, abstract = {One of the simplest principle in the design of light-weight structures is to avoid bending. This can be achieved by dissolving girders into members acting purely in axial tension or compression. The employment of cables for the tensioned members leads to even lighter structures which are called cable-strut structures. They constitute a subclass of spatial structures. To give fast information about the general feasibility of an architectural concept employing cable-strut structures is a challenging task due to their sophisticated mechanical behavior. In this regard it is essential to control if the structure is stable and if pre-stress can be applied. This paper presents a tool using the spreadsheet software Microsoft (MS) Excel which can give such information. Therefore it is not necessary to purchase special software and the according time consuming training is much lower. The tool was developed on basis of the extended Maxwell's rule, which besides topology also considers the geometry of the structure. For this the rank of the node equilibrium matrix is crucial. Significance and determination of the rank and the implementation of the corresponding algorithms in MS Excel are described in the following. The presented tool is able to support the structural designer in an early stage of the project in finding a feasible architectural concept for cable-strut structures. As examples for the application of the software tool two special cable-strut structures, so called tensegrity structures, were examined for their mechanical behavior.}, subject = {Architektur }, language = {en} } @inproceedings{Wolff1997, author = {Wolff, Ulrich}, title = {Konzept zur rechnergest{\"u}tzten integrierten Projektsteuerung im Bauwesen}, doi = {10.25643/bauhaus-universitaet.453}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4531}, year = {1997}, abstract = {Projektsteuerung gewinnt als Aufgabenfeld bei der Realisierung von Investitionsprojekten st{\"a}ndig an Bedeutung. Zur Bew{\"a}ltigung der umfangreichen und komplizierten Aufgaben des Projektsteuerers wird zunehmend Software angeboten und genutzt. Dabei ist feststellbar, daß von einer integrierten Projektsteuerung unter Ber{\"u}cksichtigung der Kriterien Leistung, Termin und Kosten nicht gesprochen werden kann, weil wesentliche theoretische und praktische Voraussetzungen fehlen. Im Beitrag werden Defizite der praktizierten Vorgehensweise und L{\"o}sungsans{\"a}tze f{\"u}r eine integrierte rechnergest{\"u}tzte Projektsteuerung vorgestellt. Durch geeignete Formen der Projektstrukturierung und eine Kopplung auf dem Mark befindlicher Standardsoftware k{\"o}nnen geeignete L{\"o}sungen gefunden werden. Problempunkte dabei stellen die Schnittstellen zwischen den Anwenderprogrammen die Datenbeschaffung und -verwaltung sowie geeignete Verfahren zur Kostenermittlung und -verfolgung dar. Im Beitrag werden eine bereits praktizierte und eine in Entwicklung befindliche L{\"o}sung vorgestellt.}, subject = {Bauwesen}, language = {de} } @inproceedings{Wolff2006, author = {Wolff, Ulrich}, title = {Die richtige Weiterbildung f{\"u}r den systematischen Kompetenzaufbau}, doi = {10.25643/bauhaus-universitaet.848}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-8480}, year = {2006}, subject = {Weimar / Bauhaus-Universit{\"a}t / Professur Baubetrieb und Bauverfahren}, language = {de} } @inproceedings{Wolff, author = {Wolff, Sebastian}, title = {NODALLY INTEGRATED FINITE ELEMENTS}, editor = {G{\"u}rlebeck, Klaus and K{\"o}nke, Carsten}, organization = {Bauhaus-Universit{\"a}t Weimar}, issn = {1611-4086}, doi = {10.25643/bauhaus-universitaet.2902}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170314-29028}, pages = {16}, abstract = {Nodal integration of finite elements has been investigated recently. Compared with full integration it shows better convergence when applied to incompressible media, allows easier remeshing and highly reduces the number of material evaluation points thus improving efficiency. Furthermore, understanding it may help to create new integration schemes in meshless methods as well. The new integration technique requires a nodally averaged deformation gradient. For the tetrahedral element it is possible to formulate a nodal strain which passes the patch test. On the downside, it introduces non-physical low energy modes. Most of these "spurious modes" are local deformation maps of neighbouring elements. Present stabilization schemes rely on adding a stabilizing potential to the strain energy. The stabilization is discussed within this article. Its drawbacks are easily identified within numerical experiments: Nonlinear material laws are not well represented. Plastic strains may often be underestimated. Geometrically nonlinear stabilization greatly reduces computational efficiency. The article reinterpretes nodal integration in terms of imposing a nonconforming C0-continuous strain field on the structure. By doing so, the origins of the spurious modes are discussed and two methods are presented that solve this problem. First, a geometric constraint is formulated and solved using a mixed formulation of Hu-Washizu type. This assumption leads to a consistent representation of the strain energy while eliminating spurious modes. The solution is exact, but only of theoretical interest since it produces global support. Second, an integration scheme is presented that approximates the stabilization criterion. The latter leads to a highly efficient scheme. It can even be extended to other finite element types such as hexahedrals. Numerical efficiency, convergence behaviour and stability of the new method is validated using linear tetrahedral and hexahedral elements.}, subject = {Angewandte Informatik}, language = {en} }